Changes in rates of arthroscopy due to degenerative knee disease and traumatic meniscal tears in Finland and Sweden

ResultsIn Finland, the annual number of operations was 16,389 in 1997, reached 20,432 in 2007, and declined to 15,018 in 2012. In Sweden, the number of operations was 9,944 in 2001, reached 11,711 in 2008, and declined to 8,114 in 2012. The knee arthroscopy incidence for OA was 124 per 10⁵ person-years in 2012 in Finland and it was 51 in Sweden. The incidence of knee arthroscopies for meniscal tears coded as traumatic steadily increased in Finland from 64 per 10⁵ person-years in 1997 to 97 per 10⁵ person-years in 2012, but not in Sweden.InterpretationThe incidence of arthroscopies for degenerative knee disease declined after 2008 in both countries. Remarkably, the incidence of arthroscopy for degenerative knee disease and traumatic meniscal tears is 2 to 4 times higher in Finland than in Sweden. Efficient implementation of new high-quality evidence in clinical practice could reduce the number of ineffective surgeries.Degenerative knee disease produces a variety of symptoms, clinical findings, and tissue abnormalities, eventually leading to knee osteoarthritis (OA). Nonoperative treatment of degenerative knee disease is recommended in guidelines, but arthroscopy is widely used (Kim et al. 2011, Nelson et al. 2014). Arthroscopic treatment includes debridement (lavage, smoothening, and removal of loose articular cartilage fragments), treatment of cartilage lesions, and resection of meniscal lesions (Felson 2010). Meniscal repair is preferred for acute traumatic tears of the meniscus (Sgaglione 2005). However, it is often difficult to distinguish between degenerative and traumatic meniscal tears. In older individuals and in patients with knee OA, meniscal tears are often degenerative and their prevalence increases with age (Curl et al. 1997, Metcalf and Barrett 2004, Englund et al. 2008). In younger patients, traumatic meniscal tears usually result from acute knee injury and are often associated with tears of the anterior cruciate ligament (Poehling et al. 1990).The practice of knee arthroscopy is in turmoil. In 2002, a pivotal randomized and placebo- (surgery) controlled trial found that arthroscopic debridement or lavage is no better than a sham procedure for treating knee OA (Moseley et al. 2002). This finding was later corroborated by Kirkley et al. (2008). This evidence led to recommendations to avoid knee arthroscopy procedures for patients with a primary diagnosis of knee OA (Conaghan et al. 2008, Richmond et al. 2009, Zhang et al. 2010). The recommendations, however, provided the option of knee arthroscopy in patients with signs and symptoms of a torn meniscus (Conaghan et al. 2008, Richmond et al. 2009) and for patients with low-grade OA (Zhang et al. 2010).Previous reports regarding the trends in a number of knee arthroscopic procedures indicate a reduced incidence of arthroscopies for knee OA, and a steady increase in the number of arthroscopic meniscus surgeries (Hawker et al. 2008, Kim et al. 2011, Abrams et al. 2013). In the UK, the incidence of arthroscopic meniscal resections more than doubled from 2000 to 2012 in patients over 60 years of age (Lazic et al. 2014). Similarly, in Denmark the number of meniscal procedures in patients aged 35 years or more increased during the period 2000–2011 (Thorlund et al. 2014).In this bi-national registry-based study involving the entire populations of Finland and Sweden, we assessed the numbers and incidence trends of arthroscopic knee procedures for degenerative knee disease and meniscal tears in Finland (between 1997 and 2012) and in Sweden (between 2001 and 2012).     

The risk of revision in total knee arthroplasty is not affected by previous high tibial osteotomy: A 15-year follow-up of 32,476 total knee arthroplasties in the Norwegian Arthroplasty Register

Background and purpose — Previous studies have found different outcomes after revision of knee arthroplasties performed after high tibial osteotomy (HTO). We evaluated the risk of revision of total knee arthroplasty with or without previous HTO in a large registry material.Patients and methods — 31,077 primary TKAs were compared with 1,399 TKAs after HTO, using Kaplan-Meier 10-year survival percentages and adjusted Cox regression analysis.Results — The adjusted survival analyses showed similar survival in the 2 groups. The Kaplan-Meier 10-year survival was 93.8% in the primary TKA group and 92.6% in the TKA-post-HTO group. Adjusted RR was 0.97 (95% CI: 0.77–1.21; p = 0.8).Interpretation — In this registry-based study, previous high tibial osteotomy did not appear to compromise the results regarding risk of revision after total knee arthroplasty compared to primary knee arthroplasty.High tibial osteotomy (HTO) is a well-established joint preserving procedure for the treatment of medial knee osteoarthritis. The goal is to achieve unloading of the affected medial compartment of the knee to prevent or postpone the need for an artificial knee joint. This is performed by slightly overcorrecting the knee joint from varus malalignment to valgus or neutral position. Osteotomy was a standard treatment option for unicompartmental knee osteoarthritis in earlier years before knee arthroplasty was a surgical option, but osteotomy lost importance in the 1980s because of the success of knee replacement surgery (Smith et al. 2013). However, there has been an increase in osteotomies during the last 15 years, especially in younger patients in some countries (Seil et al. 2013). National arthroplasty registers have demonstrated higher risk of revision for knee arthroplasty in younger patients (under the age of 60) (NAR 2014, SKAR 2013). The 2 most commonly used methods for HTO are lateral closing wedge and medial opening wedge osteotomy. Both methods have shown improvement in knee pain and function (Naudie et al. 1999, van Raaij et al. 2008, Efe et al. 2011, W-Dahl et al. 2012). Nevertheless, some patients later require a second procedure, a total knee arthroplasty (Naudie et al. 1999), depending on the degree of osteoarthritis, their level of pain and function, and the degree of correction achieved. Although total knee arthroplasty appears to be technically more challenging after HTO in cases with severe overcorrection, bone stock loss, altered joint line (Figures 1 and ​and2),2), or patella infera, only a few studies have found inferior results compared to primary TKA (Windsor et al. 1988, Parvizi et al. 2004, Haslam et al. 2007, Farfalli et al. 2012). The aim of this study was to evaluate the risk of revision after TKA, comparing primary TKA with and without previous high tibial osteotomy using data from the Norwegian Arthroplasty Register (NAR).Open in a separate windowFigure 1.Example of extra-articular malalignment after high tibial osteotomy (HTO) with opening wedge technique. The red line on the left radiograph (a) indicates the mechanical axis lateral to the knee joint. The radiograph to the right (b) indicates the extra-articular angulation of the tibia in the osteotomy area.Open in a separate windowFigure 2.Example of intra-articular malalignment after high tibial osteotomy (WTO) with closing wedge technique. The solid red line indicates that the tibial plateau has been elevated medially and is not perpendicular to the tibial axis.     

Muscular strength after total hip arthroplasty: A prospective comparison of 3 surgical approaches

ResultsDifferences in maximal strength change were greatest after 2 and 8 days. The posterior and anterior approaches produced less decrease in muscular strength than the direct lateral approach. 6 weeks postoperatively, the posterior approach produced greater increase in muscular strength than the direct lateral approach, and resulted in a greater increase in abduction strength than the anterior approach. At 3-month follow-up, no statistically significant differences between the groups were found. The operated legs were 18% weaker in leg press and 15% weaker in abduction than the unoperated legs, and the results were similar between groups.InterpretationThe posterior and anterior approaches appeared to have the least negative effect on abduction and leg press muscular strength in the first postoperative week; the posterior approach had the least negative effect, even up to 6 weeks postoperatively. THA patients have reduced muscle strength in the operated leg (compared to the unoperated leg) 3 months after surgery.Regaining muscular strength is important for postoperative function after hip arthroplasty. Inactivity reduces muscular strength and physical function (McGuire et al. 2001, Suesada et al. 2007, Kortebein et al. 2008), and muscular strength decreases substantially in the first week after total hip arthroplasty (THA) (Holm et al. 2013). Early recovery and rehabilitation of the weakened musculature is therefore of importance (Sicard-Rosenbaum et al. 2002). The type of surgical approach used has a major impact on THA stability and muscle function (Masonis and Bourne 2002).The direct lateral approach (DLA) is associated with a low dislocation risk (Witzleb et al. 2009), but of concern is that it traumatizes the abductor muscles, which can lead to permanent postoperative limp and weakness (Edmunds and Boscainos 2011). The posterior approach (PA) has been associated with postoperative dislocations (Edmunds and Boscainos 2011, Brooks 2013), mainly owing to the small femoral heads used to prevent wear (Bystrom et al. 2003). However, the introduction of highly cross-linked polyethylene into the articulation has reduced wear independently of head diameter (Bragdon et al. 2007), leading to increased use of larger head diameters (Lombardi et al. 2011). It has also been shown that a posterior soft-tissue repair following PA reduces the dislocation rate (van Stralen et al. 2003, Suh et al. 2004). The anterior approach (AA), first described by Robert Judet in 1947 as a modified Smith-Petersen approach, follows the principles of minimally invasive surgery. This approach provides intermuscular and internervous exposure to the hip (Wojciechowski et al. 2007), leading to reduced soft-tissue dissection and trauma (Bergin et al. 2011). Concerns have been related to higher complication rates owing to wound complications, intraoperative fracture, and compromised fixation after minimally invasive surgery, with increased risks of early revision surgery (Graw et al. 2010).There is no consensus on the relative functional advantages of different surgical approaches (Gulati et al. 2008, Edmunds and Boscainos 2011), and differences in maximal strength have not been examined. To our knowledge, there have been no studies comparing the DLA, the PA, and the AA in terms of early maximal muscular strength. We compared these 3 surgical approaches with regard to regaining of maximal muscular strength by 3 months postoperatively in patients undergoing THA.     

Osseointegrated total knee replacement connected to a lower limb prosthesis: 4 cases

Background and purpose — Osseointegrated implants are an alternative for prosthetic attachment in individuals with amputation who are unable to wear a socket. However, the load transmitted through the osseointegrated fixation to the residual tibia and knee joint can be unbearable for those with transtibial amputation and knee arthritis. We report on the feasibility of combining total knee replacement (TKR) with an osseointegrated implant for prosthetic attachment.Patients and methods — We retrospectively reviewed all 4 cases (aged 38–77 years) of transtibial amputations managed with osseointegration and TKR in 2012–2014. The below-the-knee prosthesis was connected to the tibial base plate of a TKR, enabling the tibial residuum and knee joint to act as weight-sharing structures. A 2-stage procedure involved connecting a standard hinged TKR to custom-made implants and creation of a skin-implant interface. Clinical outcomes were assessed at baseline and after 1–3 years of follow-up using standard measures of health-related quality of life, ambulation, and activity level including the questionnaire for transfemoral amputees (Q-TFA) and the 6-minute walk test.Results — There were no major complications, and there was 1 case of superficial infection. All patients showed improved clinical outcomes, with a Q-TFA improvement range of 29–52 and a 6-minute walk test improvement range of 37–84 meters.Interpretation — It is possible to combine TKR with osseointegrated implants.Socket-related discomfort leads to a significant reduction in the quality of life of individuals with lower limb amputation (Dillingham et al. 2001, Gholizadeh et al. 2014). Socket-skin interface problems lead to poor fit, diminished proprioception in the amputated limb, lack of rotational control, and reduction of ipsilateral proximal joint movement (Legro et al. 1999, Lyon et al. 2000, Meulenbelt et al. 2006).A direct connection of the prosthetic limb to the bone using osseointegrated implants can address these socket-related problems (Van de Meent et al. 2013, Tsikandylakis et al. 2014). Brånemark introduced this surgical procedure in 1995. He adapted osseointegration principles established in dental surgery to the rehabilitation of individuals with transfemoral amputation using a percutaneous bone anchoring implant screwed into the femur (Brånemark et al. 2001). Hip replacement spongiosa surface coating technology has been used to make a chrome cobalt intramedullary press-fit implant (Endo-Exo Prosthesis) allowing larger surface area for osseointegration and faster rehabilitation (Staubach and Grundei 2001). Al Muderis et al. (2015) adapted highly porous plasma-sprayed titanium implants to provide optimum initial press-fit and solid bone ingrowth.Studies of transfemoral implants have found improved quality of life, prosthetic use, body image, hip range of motion, sitting comfort, and walking ability (Van de Meent et al. 2013, Hagberg et al. 2014). For example, substantial improvements in health-related quality of life using the Global component of the questionnaire for transfemoral amputees (Q-TFA)—of 38 points (Hagberg et al. 2014) and 24 points (Van de Meent et al. 2013)—have been reported in 2 case series of 51 and 22 patients, respectively.Similar benefits could be expected for transtibial amputees using osseointegrated implants, as the knee joint could possibly enhance their gait. A study of 39 cases involving upper and lower limb prostheses (Tillander et al. 2010) found infections in 7 patients at an average follow-up period of 54 (3–132) months, with no infections reported for 1 tibial implant. At our own center, preliminary evidence of the safety and effectiveness of the tibial impants in 22 transtibial amputees with a minimum of 6 months of follow-up gave results consistent with the published results for transfemoral amputations (Khemka et al. 2015).Few authors have reported on the safety of this procedure (Brånemark et al. 2014, Tsikandylakis et al. 2014). One of the largest studies included 51 patients and reported superficial infections in approximately half of these patients at 2-year follow-up. In that study, the implant was removed in 1 patient due to deep infection and in 3 patients due to aseptic loosening (Brånemark et al. 2014).Osseointegrated implants are not currently recommended for transtibial amputees with ultra-short residuum. In addition to the practical technical challenges, biomechanical studies have suggested that small bone-implant contact is more likely to increase the risk of loosening (Lohr et al. 2000, Henriksen et al. 2003, Carvalho et al. 2012). Osseointegration is also not currently recommended for those suffering from ipsilateral knee osteoarthritis because it is hypothesized that an osseointegrated tibial implant will aggravate arthritic symptoms due to mechanical forces (Frossard et al. 2008).We describe the surgical procedure and early results of combining a total knee replacement (TKR) with an osseointegrated implant for prosthetic attachment for the first time.     

Perioperative local infiltration anesthesia with ropivacaine has no effect on postoperative pain after total hip arthroplasty: A randomized,double-blind,placebo-controlled trial with 116 patients

Background and purpose — The local infiltration analgesia (LIA) technique has been widely used to reduce opioid requirements and to improve postoperative mobilization following total hip arthroplasty (THA). However, the evidence for the efficacy of LIA in THA is not yet clear. We determined whether single-shot LIA in addition to a multimodal analgesic regimen would reduce acute postoperative pain and opioid requirements after THA.Patients and methods — 116 patients undergoing primary THA under spinal anesthesia were included in this randomized, double-blind, placebo-controlled trial. All patients received oral opioid-sparing multimodal analgesia: etoricoxib, acetaminophen, and glucocorticoid. The patients were randomized to receive either 150 mL ropivacaine (2 mg/mL) and 0.5 mL epinephrine (1 mg/mL) or 150 mL 0.9% saline. Rescue analgesic consisted of morphine and oxycodone as needed. The primary endpoint was pain during mobilization in the recovery unit. Secondary endpoints were pain during mobilization on the day after surgery and total postoperative opioid requirements on the first postoperative day.Results — The levels of pain during mobilization—both in the recovery unit and on the day after surgery—and consumption of opioids on the first postoperative day were similar in the 2 groups.Interpretation — LIA did not provide any extra analgesic effect after THA over and above that from the multimodal analgesic regimen used in this study.Implementation of accelerated clinical pathways based on the fast-track principles reduces morbidity and enhances recovery for patients undergoing THA (Kehlet and Wilmore 2008). One of the key prerequisites is optimized pain relief, allowing early postoperative mobilization (Kehlet and Wilmore 2008). This requires that the pain treatment should be safe and effective, both at rest and during activity (Srikandarajah and Gilron 2011).The concept of multimodal analgesia for acute postoperative pain is to combine analgesics with additive or synergistic effects, which is meant to reduce the use of—and the adverse effects of—opioids and to allow early mobilization (Kehlet and Dahl 1993, Kehlet et al. 1999, Buvanendran and Kroin 2009). Multimodal analgesia in THA usually includes analgesics such as opioids, gabapentin, NSAIDs, acetaminophen, glucocorticoids, and local infiltration (Kardash et al. 2008, Kerr and Kohan 2008, Toms et al. 2008, Fredheim et al. 2011, Maund et al. 2011, Zhang et al. 2011).Kerr and Kohan (2008) reported reduced opioid requirements and reduced hospital stay with the use of LIA consisting of ropivacaine and NSAIDs. However, trials investigating the effect of ropivacaine in LIA have not determined whether ropivacaine alone gives similar improvements following THA (Lunn et al. 2011, Dobie et al. 2012, Zoric et al. 2014). Studies using LIA have often combined different analgesics (Kerr and Kohan 2008, Kuchalik et al. 2013), and this complicates interpretation of the results regarding the extent to which ropivacaine alone contributes to the outcome.Various studies have shown that LIA does not provide any additional analgesic benefit or reduce opioid consumption after THA (Lunn et al. 2011, Dobie et al. 2012, Solovyova et al. 2013, Zoric et al. 2014), and some authors do not recommend LIA in addition to a multimodal analgesic regimen after THA (Andersen et al. 2011, Lunn et al. 2011). Other studies have shown that LIA reduces the opioid consumption (Andersen et al. 2007, Kerr and Kohan 2008, Busch et al. 2010, Murphy et al. 2012, Kuchalik et al. 2013) and shortens the hospital stay after THA (Kerr and Kohan 2008, Scott et al. 2012) The results are thus conflicting, and the role of LIA in THA surgery still needs to be clarified.We investigated whether a single-shot LIA with ropivacaine in addition to a multimodal analgesic regimen would reduce acute postoperative pain and opioid requirements after THA.     

Better survival of hybrid total knee arthroplasty compared to cemented arthroplasty: A report from the Norwegian Arthroplasty Register 1999–2012

Background and purpose — There have been few comparative studies on total knee replacement (TKR) with cemented tibia and uncemented femur (hybrid TKR). Previous studies have not shown any difference in revision rate between cemented and hybrid fixation, but these studies had few hybrid prostheses. We have evaluated the outcome of hybrid TKR based on data from the Norwegian Arthroplasty Register (NAR).Patients and methods — We compared 4,585 hybrid TKRs to 20,095 cemented TKRs with risk of revision for any cause as the primary endpoint. We included primary TKRs without patella resurfacing that were reported to the NAR during the years 1999–2012. To minimize the possible confounding effect of prosthesis brands, only brands that were used both as hybrids and cemented in more than 200 cases were included. Kaplan-Meier survival analysis and Cox regression analysis were done with adjustment for age, sex, and preoperative diagnosis. To include death as a competing risk, cumulative incidence function estimates were calculated.Results — Estimated survival at 11 years was 94.3% (95% CI: 93.9–94.7) in the cemented TKR group and 96.3% (CI: 95.3–97.3) in the hybrid TKR group. The adjusted Cox regression analysis showed a lower risk of revision in the hybrid group (relative risk = 0.58, CI: 0.48–0.72, p < 0.001). The hybrid group included 3 brands of prostheses: LCS classic, LCS complete, and Profix. Profix hybrid TKR had lower risk of revision than cemented TKR, but the LCS classic and LCS complete did not. Kaplan-Meier estimated survival at 11 years was 96.8% (CI: 95.6–98.0) in the hybrid Profix group and 95.2% (CI: 94.6–95.8) in the cemented Profix group. Mean operating time was 17 min longer in the cemented group.Interpretation — Survivorship of the hybrid TKR at 11 years was better than that for cemented TKR, or the same, depending on the brand of prosthesis. Hybrid fixation appears to be a safe and time-efficient alternative to cemented fixation in total knee replacement surgery.Total knee joint replacement (TKR) is a highly successful operation with survival rates of more than 90% at 10 years (Carr et al. 2012). Only a few large comparative studies on different designs have been published (Knutson et al. 1986, Rand and Ilstrup 1991, Knutson et al. 1994, Robertsson 2000, Furnes et al. 2002, 2007, Sibanda et al. 2008). Most previous studies were not conclusive, due to their being too small or being biased with potential conflicts of interests (Carr et al. 2012). In the only meta-analysis on this topic, Nakama et al. (2012) found only 3 small randomized controlled studies that could be included for quantitative analysis. These authors were not able to make any conclusions about whether the prostheses should be cement-fixated, cementless, or hybrid.The fixation of primary TKRs has been extensively discussed, but no general agreement has been reached (Nakama et al. 2012). Cemented prostheses are regarded as the gold standard for TKR, supported by the long-term clinical success and survivorship analysis from registry-based and clinical studies (Robertsson 2000, Bellemans et al. 2005, Nakama et al. 2012). Cementless fixation is, however, still of interest to clinicians, who have used it in an attempt to reduce operation time, improve prosthetic durability, and preserve bone stock (Bassett 1998, Duffy et al. 1998, Nelissen et al. 1998, Regner 1998, Abu-Rajab et al. 2006).There have been few studies comparing the survival of different prosthesis brands and implant designs. A previous study from the Norwegian Arthroplasty Register (NAR) did not find any significant short-term differences at 5 years between the most commonly used brands in Norway (Furnes et al. 2002). The study did not show any significant differences in the overall revision rates between different fixation methods, but the number of hybrid prostheses was low, with only 739 knees (10%). The median follow-up time was short, number of prosthesis brands was high (7), and the power of the study was low regarding fixation method, due to low numbers of hybrid and cementless prostheses.In Sweden, almost all TKRs are cemented (SKAR, 2012). In Australia, there is more variation in fixation; more than 20% of TKRs have hybrid fixation (AOA 2012). In the report from 2011, for the first time hybrid fixation performed better than both cemented and cementless fixation at 10 years. Annual cumulative percent revision of primary TKR at 10 years was 5.6% (5.3–6.0) with cement fixation and 5.0 (4.6–5.3) with hybrid fixation (p = 0.02) (AOA 2012).There have been very few randomized prospective studies comparing primary TKRs using cemented fixation and primary TKRs using hydroxyapatite-coated, hybrid fixation. Most of them have compared uncemented fixation of the tibia and cemented fixation of the tibia. These studies have shown similar or inferior results for uncemented fixation (Nilsson et al. 1999, Regner et al. 2000, Carlsson et al. 2005, Beauprè et al. 2007). Short-term studies of hybrid fixation with cemented femur showed promising results (Faris et al. 2008). However, 1 medium-term report of 65 press-fit condylar arthroplasties had unacceptable implant survivorship and problems with the femoral component (Campbell et al. 1998).We compared the failure rates and mechanisms of failure of primary hybrid TKRs with those of primary cemented TKRs using the nationwide prospective observational register of knee implants in Norway.     

Local delivery of a selective androgen receptor modulator failed as an anabolic agent in a rat bone marrow ablation model

Background and purpose — Selective androgen receptor modulators (SARMs) have been developed to have systemic anabolic effects on bones and muscles without the adverse effects of steroidal androgens. One unexplored therapeutic option is the targeted application of SARMs for the enhancement of local new bone formation. We evaluated the osteogenic efficacy of a locally released SARM (ORM-11984).Methods — ORM-11984 was mixed with a copolymer of L-lactide and ɛ-caprolactone (PLCL). An in vitro dissolution test confirmed the sustainable release of ORM-11984 from the matrix. A bone marrow ablation model was used in female Sprague-Dawley rats. Implants containing 10%, 30%, or 50% ORM-11984 by weight or pure PLCL were inserted into the medullary canal of the ablated tibia. At 6 and 12 weeks, the volume of intramedullary new bone and the perimeter of bone-implant contact were measured by micro-computed tomography and histomorphometry.Results — Contrary to our hypothesis, there was a negative correlation between the amount of new bone around the implant and the dose of ORM-11984. There was only a mild (and not statistically significant) enhancement of bone formation in ablated bones subjected to the lowest dose of the SARM (10%).Interpretation — This study suggests that intramedullary/endosteal osteogenesis had a negative, dose-dependent response to locally released SARM. This result highlights the complexity of androgenic effects on bones and also suggests that there are biological limits to the targeted local application of SARMs.Male and female hormones, which act mainly via androgen receptors (ARs) and estrogen receptors (ERs), are physiological regulators of bone remodeling (Clarke and Khosla 2009, Vanderschueren et al. 2014). Drug development programs have successfully launched non-steroidal selective estrogen receptor modulators (SERMs) for various clinical indications, including postmenopausal osteoporosis (Komm and Mirkin 2014). The common goal of the corresponding programs for non-steroidal tissue-selective androgen receptor modulators (SARMs), which act as AR ligands, is to achieve systemic anabolic effects on bones and muscles without adverse androgenic effects (Mohler et al. 2009). Preclinical models have shown that the systemic administration of SARMs can protect the skeleton from the catabolic effects of orchiectomy and ovariectomy (Gao et al. 2005, Kearbey et al. 2007), partially restore the bone mass lost by ovariectomy (Kearbey et al. 2009), and enhance the therapeutic effects of anti-resorptive drug treatment (Vajda et al. 2009). The main clinical target of SARMs is aging populations with sarcopenia and bone frailty (Mohler et al. 2009), but no SARMs have yet reached the market.ARs are highly expressed in mature osteoblasts and osteocytes (Abu et al. 1997, Wiren et al. 2002), and androgens have been traditionally claimed to have direct anabolic bone effects. Data from studies on androgen-insensitive null mice with non-functional ARs (Yeh et al. 2002, Kawano et al. 2003, Venken et al. 2006, Sinnesael et al. 2012) and in mice that overexpress ARs (Wiren et al. 2004, 2008) have confirmed the physiological significance of AR-mediated bone remodeling processes. The androgenic action may be partly compartment-specific, and anabolic effects mainly appear at periosteal surfaces (Wiren et al. 2004, 2008, 2010, 2011), but several studies have clearly demonstrated that the lack of AR action results in general trabecular bone loss (Vanderschueren et al. 2014).Clinically, there are unmet needs for bone enhancement agents in elective reconstructive procedures and also in trauma surgery. One unexplored therapeutic option would be local application of SARMs as an anabolic bone agent. In this pilot study, the osteogenic efficacy of a SARM compound (ORM-11984) was tested in a rat bone marrow ablation model. Bone marrow ablation is a unique bone-healing model in which robust endosteal intramembranous bone formation is induced transiently by surgical ablation of the bone marrow (Suva et al. 1993). ARs are present in mesenchymal stromal stem cells of the bone marrow (Bellido et al. 1995), which are among the repair cells responsible for bone-healing processes (Bais et al. 2009). We hypothesized that the intramedullary administration of ORM-11984 would have androgenic anabolic effects on bone marrow-derived precursor cells and produce a dose-dependent enhancement of the local osteogenic response.     

Which patients do not recover from shoulder impingement syndrome,either with operative treatment or with nonoperative treatment?: Subgroup analysis involving 140 patients at 2 and 5 years in a randomized study

Background and purpose — Shoulder impingement syndrome is common, but treatment is controversial. Arthroscopic acromioplasty is popular even though its efficacy is unknown. In this study, we analyzed stage-II shoulder impingement patients in subgroups to identify those who would benefit from the operation.Patients and methods — In a previous randomized study, 140 patients were either treated with a supervised exercise program or with arthroscopic acromioplasty followed by a similar exercise program. The patients were followed up at 2 and 5 years after randomization. Self-reported pain was used as the primary outcome measure.Results — Both treatment groups had less pain at 2 and 5 years, and this was similar in both groups. Duration of symptoms, marital status (single), long periods of sick leave, and lack of professional education appeared to increase the risk of persistent pain despite the treatment. Patients with impingement with radiological acromioclavicular (AC) joint degeneration also had more pain. The patients in the exercise group who later wanted operative treatment and had it did not get better after the operation.Interpretation — The natural course probably plays a substantial role in the outcome. Based on our findings, it is difficult to recommend arthroscopic acromioplasty for any specific subgroup. Regarding operative treatment, however, a concomitant AC joint resection might be recommended if there are signs of AC joint degeneration. Even more challenging for the development of a treatment algorithm is the finding that patients who do not recover after nonoperative treatment should not be operated either.Shoulder impingement syndrome has traditionally been divided into 3 progressive stages: (1) edema and hemorrhage (stage I), (2) fibrosis and tendinitis (stage II), and (3) tears of the rotator cuff, biceps ruptures, and bone changes (stage III) (Neer 1983). Nowadays, the term impingement syndrome is used to refer to a full range of rotator cuff abnormalities, being still a diagnosis based on physical examination (Papadonikolakis et al. 2011). Diercks et al. (2014) highlighted the need for a combination of clinical tests in the diagnosis, and suggested the use of an imaging test after prolonged symptoms (of more than 6 weeks) to rule out rotator cuff tears. Shoulder impingement is a common cause of shoulder pain (van der Windt et al. 1995, Urwin et al. 1998). Tendinopathy is considered to have a multifarious etiology: intrinsic mechanisms may be more important than extrinsic mechanisms (Factor and Dale 2014).Both nonoperative treatment and operative treatment have been used to treat this syndrome (Coghlan et al. 2008, Dorrestijn et al. 2009, Kromer et al. 2009, Chaudhury et al. 2010). It has been shown that arthroscopic acromioplasty is not superior to a supervised exercise program (Ketola et al. 2009, 2013, Papadonikolakis et al. 2011, Diercks et al. 2014, Saltychev et al. 2015). However, arthroscopic acromioplasty has been increasingly used during the last decade (Paloneva et al. 2015). Similar results have been obtained with open and arthroscopic acromioplasty (Davis et al. 2010). It is unclear whether a specific subgroup of patients who would benefit from arthroscopic acromioplasty can be identified. In most studies, the inclusion criterion has simply been failure of nonoperative treatment (Brox et al. 1999, Henkus et al. 2009). We have already done a cost-effectiveness study that suggested that arthroscopic acromioplasty followed by a structural exercise program is less cost-effective than exercise treatment alone (Ketola et al. 2009), and this was confirmed by Saltychev et al. (2015). We have now analyzed the 140 impingement patients from our previous study (Ketola et al. 2009) in subgroups to find out whether there is a subgroup of patients who would really benefit from arthroscopic acromioplasty. Secondly, we wanted to determine whether there is a subgroup in which the procedure should be avoided.     

The role of “cell therapy” in osteonecrosis of the femoral head: A systematic review of the literature and meta-analysis of 7 studies

ResultsThe pooled estimate of effect size for structural failure of the femoral head favored the cell therapy group, as, in this treatment group, the odds of progression of the femoral head to the collapse stage were reduced by a factor of 5 compared to the CD group (odds ratio (OR) = 0.2, 95% CI: 0.08–0.6; p = 0.02). The respective summarized estimate of effect size yielded halved odds for conversion to THR in the cell therapy group compared to CD group (OR = 0.6, 95% CI: 0.3–1.02; p = 0.06).InterpretationOur findings suggest that implantation of autologous mesenchymal stem cells (MSCs) into the core decompression track, particularly when employed at early (pre-collapse) stages of ONFH, would improve the survivorship of femoral heads and reduce the need for hip arthroplasty.Osteonecrosis of the femoral head (ONFH) is a progressive disease caused by a critical reduction in the blood supply to the femoral head and elevation of intraosseous pressure. Although its pathogenesis is poorly understood, it is generally accepted that various traumatic and non-traumatic insults compromise the already precarious circulation of the femoral head, leading to bone marrow and osteocyte death—and eventually collapse of the necrotic segment (Mont and Hungerford 1995). It mostly affects young adults, causing considerable morbidity (Slobogean et al. 2015). The annual incidence of ONFH in the USA is estimated to be 15,000–20,000 cases (Vail and Covington 1997). Most cases without any treatment progress to femoral head collapse and joint destruction, with total hip arthroplasty being the only treatment option (Lieberman et al., 2003). Magnetic resonance imaging (MRI) has contributed to early (pre-collapse) detection of the disease, providing an opportunity for timely intervention in order to avoid femoral head collapse and subsequent joint destruction.Various nonoperative and operative treatment modalities have been used to prevent—or at least delay—the progress of the disease towards femoral head collapse. Core decompression is a commonly used procedure, particularly in pre-collapse stages, but its effectiveness remains controversial (Ficat 1985, Learmonth et al. 1990, Markel et al. 1996, Saito et al. 1988, Yoon et al. 2001). Current research has focused on clarifying the molecular mechanisms involved in the pathogenesis of ONFH (Gangji and Hauzeur 2009, Kasten et al. 2008, Lee et al. 2009). Particular attention has been paid to multipotent mesenchymal stem cells (MSCs) and their ability to maintain mitotic multiplication while being capable of differentiating into various cellular types, such as osteoblasts, osteocytes, chondrocytes, and adipocytes (Baksh et al. 2004). Experimentally, MSCs have been shown to enhance tissue regeneration when transplanted in areas of necrotic bone (Yan et al. 2009). Various researchers have pioneered the clinical application of cell-based methods for the treatment of ONFH (Hernigou and Beaujean 2002, Gangji and Hauzeur 2005, Calori et al. 2014). Their technique was used in conjunction with the classical core decompression procedure and involved harvesting of autologous bone marrow aspirate, isolation of its mononuclear cell fraction, and injection of it into the necrotic zone of the femoral head through the canal of the preceding core decompression. This treatment strategy was based on the hypothesis that multiipotent MSCs in the bone marrow aspirate could repopulate the trabeculae of the necrotic zone within the femoral head, enhancing regeneration and remodeling of the necrotic bone (Hernigou et al. 2004).We performed a meta-analysis to investigate whether implantation of autologous bone marrow aspirate, containing MSCs, into the core decompression track would improve the clinical and radiological results of ONFH compared to the classical method of core decompression alone. The primary outcomes of interest were structural failure (collapse) of the femoral head and conversion to total hip replacement (THR).     

Effect of rotational alignment on outcome of total knee arthroplasty: A systematic review of the literature and correlation analysis

Background and purpose

Poor outcomes have been linked to errors in rotational alignment of total knee arthroplasty components. The aims of this study were to determine the correlation between rotational alignment and outcome, to review the success of revision for malrotated total knee arthroplasty, and to determine whether evidence-based guidelines for malrotated total knee arthroplasty can be proposed.

Patients and methods

We conducted a systematic review including all studies reporting on both rotational alignment and functional outcome. Comparable studies were used in a correlation analysis and results of revision were analyzed separately.

Results

846 studies were identified, 25 of which met the inclusion criteria. From this selection, 11 studies could be included in the correlation analysis. A medium positive correlation (ρ = 0.44, 95% CI: 0.27–0.59) and a large positive correlation (ρ = 0.68, 95% CI: 0.64–0.73) were found between external rotation of the tibial component and the femoral component, respectively, and the Knee Society score. Revision for malrotation gave positive results in all 6 studies in this field.

Interpretation

Medium and large positive correlations were found between tibial and femoral component rotational alignment on the one hand and better functional outcome on the other. Revision of malrotated total knee arthroplasty may be successful. However, a clear cutoff point for revision for malrotated total knee arthroplasty components could not be identified.About 1 in 5 TKA patients are dissatisfied with the outcome (Bourne et al. 2010). A systematic review by the European Arthroplasty Register reported the results of 6 national joint registry datasets. A combined revision rate of 1.3 revisions per 100 observed component years after primary TKA was reported, and revision rates of about 6% after 5 years and 12% after 10 years are to be expected (Labek et al. 2011). Many possible causes of painful or malfunctioning TKAs have been defined, but the true cause often remains unknown (Thornhill 2002, Dennis 2004, Toms et al. 2009). Rotational errors of TKA components are frequently overlooked as the origin of problems, which can lead to unnecessary procedures (Bedard et al. 2011). Poor outcomes and major complications—e.g. patellofemoral pain, instability, and stiffness after TKA—have been linked to errors in rotational alignment of the components (Mochizuki and Schurman 1979, Rhoads et al. 1990, Berger et al. 1998, Miller et al. 2001, Sikorski 2008). Thus, the aims of the present study were (1) to examine the correlation between rotational alignment of the TKA component and outcome, (2) to review the results of revision operations for rotational malaligned TKA, and (3) to investigate whether practical recommendations can be made to guide treatment of a rotational malaligned TKA.     

PTH 1-34 (teriparatide) may not improve healing in proximal humerus fractures: A randomized,controlled study of 40 patients

Results39 patients completed the follow-up. The radiographic assessment showed a correct correlation, “better” in the teriparatide group and “normal” in the control group, in 21 of the 39 cases. There were no statistically significant differences in pain, in use of strong analgesics, or in function between the groups at the follow-up examinations.InterpretationThere were no radiographic signs of enhanced healing or improved clinical results in the group treated with teriparatideDuring the last 15 years, researchers have tried to improve fracture healing by using additional medication or growth factors such as bisphosphonates, bone morphogenetic proteins (BMPs), and parathyroid hormone (PTH). The hopes for improvement involved 2 different considerations, faster fracture healing and a reduced proportion of non-unions (Aspenberg 2013).Bisphosphonates, systemic or locally administered, have been shown to improve implant fixation, but their role in fracture treatment is unclear (Abtahi et al. 2012, Hilding and Aspenberg 2006, 2007). BMPs are thought to initiate fracture healing, but they have obvious side effects such as local swelling, pain, and increased risk of wound infections (Aro et al. 2011, Carragee et al. 2011). Studies sponsored by industry have obviously not reported the adverse effects associated with the administration of BMPs in spinal fusion (Carragee et al. 2011). There is also reason to believe that there is an increased risk of cancer after BMP treatment (Carragee et al. 2013).Animal studies have shown that there is accelerated fracture healing after intermittent injections with parathyroid hormone (PTH) (Skripitz and Aspenberg 2004, Chalidis et al. 2007). So far, only 3 papers have been published concerning PTH and fracture repair in humans. 2 papers with data from the same randomized trial involving distal radius fractures showed accelerated healing and improved callus formation (Aspenberg et al. 2010, Aspenberg and Johansson 2010). The radiological analysis showed minimal improvement in the position of the healed fracture, and there was no improvement in function. The third paper compared PTH 1-84 with placebo, and showed better healing in pubic bone fractures at 2 months in the treatment group, together with less pain and better walking ability (Peichl et al. 2011). However, that study had some methodological shortcomings. In conclusion, these studies have suggested that PTH may improve fracture healing in humans but the clinical importance for different diagnoses must be investigated and confirmed.The main aim of this study was to determine whether teriparatide enhances fracture healing of proximal humerus fractures, as evaluated on radiographs at 7 weeks. Secondary aims were to compare function, pain, and the use of opioid analgesics before the fracture, at 7 weeks, and after 3 months.     

Preliminary experience with the patient-specific templating total knee arthroplasty

Background and purpose

Patient-specific templating total knee arthroplasty (TKA) is a new method for alignment of a total knee arthroplasty that uses disposable guides. We present the results of the first 40 consecutive patients who were operated on using this technique.

Methods

In this case-control study, we compared blood loss, operation time, and alignment of 40 TKAs performed using a patient-specific templating alignment technique with values from a matched control group of patients who were operated on by conventional intramedullary alignment technique. Alignment of the mechanical axis of the leg and flexion/extension and varus/valgus of the individual prosthesis components were measured on standing, long-leg, and standard lateral digital radiographs. The fraction of outliers (> 3˚) was determined.

Results

Mean mechanical axis of templating TKAs was 181° with a fraction of outliers of 0.3, and mean mechanical axis of conventional TKAs was 179˚ (outlier fraction 0.5). Fraction of outliers in the frontal plane for femoral components was 0.05 in the templating TKAs and 0.4 in the conventional TKAs, and for tibial components the corresponding values were 0.2 and 0.2. In the templating TKAs and conventional TKAs, fraction of outliers in the sagittal plane was 0.4 and 0.9, respectively, for femoral components and 0.4 and 0.6 for tibial components. Mean operation time was 10 min shorter and blood loss was 60 mL less for templating TKA than for intramedullary-aligned TKAs.

Interpretation

Patient-specific templating TKA showed improved accuracy of alignment and a small reduction in blood loss and operating time compared to intramedullary-aligned TKA, but the fraction of outliers was relatively high. Larger RCTs are needed for further evaluation of the technique and to define the future role of patient-specific template alignment techniques for TKA.Nowadays, there are several methods for alignment of total knee arthroplasties (TKAs). These alignment methods can be divided into conventional techniques and navigational or image-guided surgery.Complications associated with conventional techniques that use intramedullary alignment rods include extra blood loss perioperatively (Raut et al. 1993), embolization of medullary content (Caillouette and Anzel 1990, Fahmy et al. 1990), and difficulty in intramedullary rod passage due to deformity, retained hardware, or pathological bone disease (Dennis et al. 1993). An important factor influencing implant survival is the alignment of the mechanical axis; malalignment is associated with poorer survivorship (Lotke and Ecker 1977, Bargren et al. 1983, Jeffery et al. 1991, Ritter et al. 1994,), substantial change in pressure distribution (Hsu et al. 1990), and change in total load in the medial and lateral compartments of the tibial component (Werner et al. 2005). Computer navigation has been developed to improve implant and limb alignment and instability in conventionally placed prostheses (Beringer et al. 2007). A recent meta-analysis showed that malalignment of the mechanical axis of more than 3° occurs in one third of conventional TKA patients. In contrast, only one tenth of computer-assisted TKAs result in malalignment of the mechanical axis of more than 3° (Mason et al. 2007).Peroperative navigation has some major drawbacks, however. They include the need for accurate landmark registration (Lombardi et al. 2008), increased surgical time and cost (Radermacher et al. 1998, Lombardi et al. 2008), pin loosening and bone fractures (Lombardi et al. 2008), complexity (Radermacher et al. 1998), long set-up time (Radermacher et al. 1998), and a substantial learning curve (Lombardi et al. 2008).Recently, a patient-specific alignment guide, Signature Personalized Patient Care (SPPC) (Biomet Inc., Warsaw, IN) was developed, based on a preoperative MRI scan of the patient’s leg. With this alignment guide the intramedullary cavity is not opened, thus eliminating the risks associated with it. In addition, the new technique theoretically eliminates most of the disadvantages of intraoperative navigation.We present the preliminary results of our first 40 consecutive cases operated with this new technique and compared them with results from a matched control group operated using conventional intramedullary alignment technique. We expected operation time and degree of blood loss to be lower in the SPPC group. Alignment, in terms of fraction of outliers, was expected to be superior in the SPPC group than in the conventional intramedullary alignment technique.     

Quadriceps force after TKA with femoral single radius

Background and purpose

New implant designs have incorporated a single radius instead of a multiple radius to the femoral component in order to improve the mechanical function after TKA. We investigated the amount of quadriceps force required to extend the knee during an isokinetic extension cycle of different total knee designs, focusing on the radius of the femoral component (single vs. multiple).

Methods

Human knee specimens (n = 12, median patient age 68 (63–70) years) were tested in a kinematic knee-simulating machine untreated and after implantation of 2 types of knee prosthesis systems, one with a single femoral radius design and one with a multiple femoral radius design. During the test cycle, a hydraulic cylinder, which simulated the quadriceps muscle, applied sufficient force to the quadriceps tendon to produce a constant extension moment of 31 Nm. The quadriceps extension force was measured from 120° to full knee extension.

Results

The shape of the quadriceps force curve was typically sinusoidal before and after TKA, reaching a maximum value of 1,493 N at 110°. With the single femoral radius design, quadriceps force was similar to that of the normal knee: 1,509 N at 110° flexion (p = 0.4). In contrast, the multiple femoral radius design showed an increase in quadriceps extension force relative to the normal knee, with a maximum of 1,721 N at 90° flexion (p = 0.03).

Interpretation

The single femoral radius design showed lower maximum extension forces than the multiple femoral radius design. In addition, with the single femoral radius design maximum quadriceps force needed to extend a constant extension force shifted to higher degrees of knee flexion, representing a more physiological quadriceps force pattern, which could have a positive effect on knee function after TKA.Even patients with excellent results after total knee arthroplasty (TKA) have an altered walking pattern with less flexion, a shorter swing phase, and a weaker extension strength in the operated knee (Andriacchi et al. 1982, Dorr 1988, Wimmer 1999). Although patients may improve upon their preoperative extension strength by up to 50%, they do not reach the level of healthy subjects (Berman et al. 1991, Fuchs et al. 1998, 2004).Abnormal muscle function after TKA could be due to loss of proprioreception, muscle capacity, prosthesis design, or alternations in lever arms and extension moments. With the sacrifice of the anterior cruciate ligament, the lever arm of the extensor mechanism is reduced due to a paradoxical anterior movement of the femur relative to the tibia during flexion, which results in higher quadriceps muscle forces required to extend the knee (Lewandowski et al. 1997, Dennis et al. 1998a, Ostermeier et al. 2004).Previous biomechanical studies have shown that after stabilization of the flexion/extension axis, this paradoxical movement is reduced and the quadriceps lever arm is improved or almost restored to physiological levels, which could result in higher extension forces (Heyse et al. 2009). Hinged prostheses in particular offer this stability with improved extension force in vitro (Ostermeier et al. 2008). Non-hinged TKA designs with a single radius of the femoral condyles also offer a potential minimization of this paradoxical movement, as the flexion-extension axis is kinematically stabilized, which could increase the quadriceps lever arm (Kessler et al. 2007). Thus, the purpose of this in vitro study was to investigate the amount of quadriceps force required to extend the knee during an isokinetic extension cycle before and after total knee arthroplasty with 2 knee prosthesis systems, representing multiple and single femoral radius designs. We hypothesized that with a single femoral radius design, quadriceps force is restored to physiological levels while this is not achieved with a multiple femoral radius design.     

Outcome of total hip arthroplasty,but not of total knee arthroplasty,is related to the preoperative radiographic severity of osteoarthritis: A prospective cohort study of 573 patients

ResultsAdjusted for sex, age, preoperative scores, BMI, and Charnley score, radiographic severity of OA in THA was associated with improvement in HOOS “Activities of daily living”, “Pain”, and “Symptoms”, and SF36 physical component summary (“PCS”) scale. In TKA, we found no such associations.InterpretationThe decrease in pain and improvement in function in THA patients, but not in TKA patients, was positively associated with the preoperative radiographic severity of OA.DiscussionThis prospective study in patients undergoing THA and TKA showed that changes in scores over time were greater in patients with more severe radiographic OA. The difference was statistically significant for a number of clinical outcomes in THA patients, but not in TKA patients.Overall, our results are in line with the literature, with the majority of studies concluding that more severe radiographic OA preoperatively is associated with better outcomes in THA or TKA (Dowsey et al. 2012, Valdes et al. 2012, Keurentjes et al. 2013). Concerning THA specifically, similar to the present study, Valdes et al. (2012) reported greater improvements in pain 3 years after surgery in patients with severe radiographic OA preoperatively. Greater improvements in the SF subscale and summary scale scores were seen in patients with higher KL scores in a study by Keurentjes et al. (2013), but the differences were not statisticaly significant.Regarding TKA, our study did not show any statistically significant differences between the outcomes in patients with different grades of radiographic severity, although—as in the study by Cushnaghan et al. (2009)—greater improvements were generally seen in patients with higher KL grades. In contrast, Valdes et al. (2012) and Keurentjes et al. (2013) found statistically significantly better outcomes in TKA patients with severe radiographic OA, and similar results were seen in some of the analyses in the study by Dowsey et al. (2012). Comparisons with the literature are, however, hampered by the large diversity in study designs and analyses.It is difficult to draw conclusions about the clinical relevance of the results of our study and of previous ones. Firstly, there are several factors associated with worse outcomes after THA/TKA, such as older age, female sex, obesity, worse general health, involvement of other joints, and a lower level of education (Dieppe et al. 2009, Gossec et al. 2011). Only from large, prospective studies using a standardized set of preoperative characteristics and outcome assessments done at fixed time points can true prediction models including all potentially relevant determinants be derived, which afterwards need to be validated in multiple settings and countries. However, we can interpret the absolute change scores as observed in the different groups according to radiographic severity. A recent systematic review by Keurentjes et al. (2012) found that overall minimally clinically important differences (MICDs) in HRQoL in THA/TKA have limited precision and are not validated using external criteria. The study which is most comparable to our study is that from Clement et al. (2014). In that study, the MCID in OKS for the difference between preoperatively and 1 year postoperatively was 15.5 (95% CI: 14.7–16.4). In our study, generally patients in both the mild and severe OA groups achieved this improvement, indicating that the clinical relevance of a statistically significant difference may be limited.A main strength of our study was the inclusion of a wide range of validated PROMs, covering all items of disease-specific outcome measures in functioning, pain, and health-related quality of life. Using all these outcome measures, both measures of pain and daily activities, we observed differences between groups according to radiographic severity. Another strength was that all radiographs were read by a single observer with extensive experience, who was blinded regarding patient data. In addition, this was a prospective study with a relatively large cohort with only 20% loss to follow-up in the THA group and only 23% loss to follow-up in the TKA group.Our study also had a number of limitations. It only included KL grading applied to the anteroposterior and posteranterior radiographs from the preoperative hip and knee.In the study by Dowsey et al. (2012), not only KL grading but also the severity of joint space narrowing (JSN; 0–3) and osteophyte formation (0–3) using the Osteoarthritis Research Society International (OARSI) atlas, and the degree of bone attrition, were taken into account. In that study, radiographs showing advanced OA (KL 3–4) were further subdivided by including data from the individual score of JSN and bone attrition.In addition, the patients included in the present study were a selection of all patients who underwent THA or TKA and it was carried out in 1 center in 1 country. However, the preoperative characteristics of the patients and their change scores over time are well in line with those observed in other large cohorts (Nilsdotter et al. 2003, Dieppe et al. 2009, Beswick et al. 2012).In conclusion, this study shows that in patients who underwent THA, but not TKA, more severe radiographic OA preoperatively was associated with a better outcome regarding pain and function.

Supplementary data

Tables 1 and 2 are available on the Acta Orthopaedica website, www.actaorthopaedica.org, identification number 8277.CT, MF, and TPMVV: conception and design, analysis and interpretation of the data, drafting of the article, provision of study materials or patients, statistical expertise, and collection and assembly of data. MJH, RLT, HMK, CSL, and SHM: provision of study materials or patients, administrative, technical, or logistic support, and collection and assembly of data. HMK and RGHHN: critical revision of the article, statistical expertise.This study was supported by the Dutch Arthritis Association (grant number LLP13).No competing interests declared.     

Role of preoperative pain,muscle function,and activity level in discharge readiness after fast-track hip and knee arthroplasty

Methods Before surgery, hip pain (THA) or knee pain (TKA), lower-extremity muscle power, functional performance, and physical activity were assessed in a sample of 150 patients and used as independent variables to predict the outcome (dependent variable)—readiness for hospital discharge —for each type of surgery. Discharge readiness was assessed twice daily by blinded assessors.Results Median discharge readiness and actual length of stay until discharge were both 2 days. Univariate linear regression followed by multiple linear regression revealed that age was the only independent predictor of discharge readiness in THA and TKA, but the standardized coefficients were small (≤ 0.03).Interpretation These results support the idea that fast-track THA and TKA with a length of stay of about 2–4 days can be achieved for most patients independently of preoperative functional characteristics.Over the last decade, length of stay (LOS) with discharge to home after primary THA and TKA has declined from about 5–10 days to about 2–4 days in selected series and larger nationwide series (Malviya et al. 2011, Raphael et al. 2011, Husted et al. 2012, Kehlet 2013, Hartog et al. 2013, Jørgensen and Kehlet 2013). However, there is a continuing debate about whether selected patients only or all patients should be scheduled for “fast-track” THA and TKA in relation to psychosocial factors and preoperative pain and functional status (Schneider et al. 2009, Hollowell et al. 2010, Macdonald et al. 2010, Antrobus and Bryson 2011, Jørgensen and Kehlet 2013), or whether organizational or pathophysiological factors in relation to the surgical trauma may determine the length of stay (Husted et al. 2011, Husted 2012).We studied the role of THA and TKA patients’ preoperative pain and functional characteristics in discharge from 2 orthopedic departments with well-established fast-track recovery regimens (Husted et al. 2010).     

Metal-backed versus all-polyethylene tibial components in primary total knee arthroplasty

Background and purpose

The choice of either all-polyethylene (AP) tibial components or metal-backed (MB) tibial components in total knee arthroplasty (TKA) remains controversial. We therefore performed a meta-analysis and systematic review of randomized controlled trials that have evaluated MB and AP tibial components in primary TKA.

Methods

The search strategy included a computerized literature search (Medline, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials) and a manual search of major orthopedic journals. A meta-analysis and systematic review of randomized or quasi-randomized trials that compared the performance of tibial components in primary TKA was performed using a fixed or random effects model. We assessed the methodological quality of studies using Detsky quality scale.

Results

9 randomized controlled trials (RCTs) published between 2000 and 2009 met the inclusion quality standards for the systematic review. The mean standardized Detsky score was 14 (SD 3). We found that the frequency of radiolucent lines in the MB group was significantly higher than that in the AP group. There were no statistically significant differences between the MB and AP tibial components regarding component positioning, knee score, knee range of motion, quality of life, and postoperative complications.

Interpretation

Based on evidence obtained from this study, the AP tibial component was comparable with or better than the MB tibial component in TKA. However, high-quality RCTs are required to validate the results.The design of the tibial component is an important factor for implant failure in total knee arthroplasty (TKA) (Pagnano et al. 1999, Forster 2003, Gioe et al. 2007b, Willie et al. 2008, Garcia et al. 2009, KAT Trial Group 2009). The metal-backed (MB) design of tibial component has become predominant in TKA because it is thought to perform better than the all-polyethylene (AP) design (Muller et al. 2006, Gioe et al. 2006, 2007a,b). In theory, the MB tibial component reduces bending strains in the stem, reduces compressive stresses in the cement and cancellous bone beneath the baseplate (especially during asymmetric loading), and distributes load more evenly across the interface (Bartel et al. 1982, 1985, Taylor et al. 1998). However, critics of the MB tibial component claim that there are expensive implant costs, reduced polyethylene thickness with the same amount of bone resection, backside wear, and increased tensile stresses at the interface during eccentric loading (Bartel et al. 1982, 1985, Pomeroy et al. 2000, Rodriguez et al. 2001, Li et al. 2002, Muller et al. 2006, Blumenfeld and Scott 2010, Gioe and Maheshwari 2010).In the past decade, several randomized controlled trials (RCTs) have been performed to assess the effectiveness of the MB tibial component (Adalberth et al. 2000, 2001, Gioe and Bowman 2000, Norgren et al. 2004, Hyldahl et al. 2005a, b, Muller et al. 2006, Gioe et al. 2007, Bettinson et al. 2009, KAT Trial Group 2009). However, data have not been formally and systematically analyzed using quantitative methods in order to determine whether the MB tibial component is indeed optimal for patients in TKA. In this study, we wanted (1) to determine the scientific quality of published RCTs comparing the AP and MB tibial components in TKA using Detsky score (Detsky et al. 1992) and (2) to conduct a meta-analysis and systematic review of all published RCTs that have compared the effects of AP and MB tibial components on the radiographic and clinical outcomes of TKA.     

Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block

Background and purpose

Pain after total knee arthroplasty (TKA) is usually severe, and epidural analgesia or femoral nerve block has been considered to be an effective pain treatment. Recently, local infiltration analgesia (LIA) has become increasingly popular but the outcome of this method regarding the analgesic effect has not been fully evaluated. We compared local infiltration analgesia and femoral block with regard to analgesia and morphine demand during the first 24 h after TKA.

Methods

40 patients undergoing TKA under spinal anesthesia were randomized to receive femoral nerve block (group F) or peri- and intraarticular infiltration analgesia (group LIA) with a mixture containing ropivacaine, ketorolac, and epinephrine. All patients had access to intravenous patient-controlled analgesia (PCA) with morphine postoperatively. Pain intensity at rest and upon movement was assessed on a numeric rating scale (0–10) on an hourly basis over 24 h if the patients were awake.

Results

The average pain at rest was marginally lower with LIA (1.6) than with femoral block (2.2). Total morphine consumption per kg was similar between the 2 groups. Ancillary analysis revealed that 1 of 20 patients in the LIA group reported a pain intensity of > 7 upon movement, as compared to 7 out of 19 in the femoral block group (p = 0.04).

Interpretation

Both LIA and femoral block provide good analgesia after TKA. LIA may be considered to be superior to femoral block since it is cheaper and easier to perform.Pain after total knee arthroplasty (TKA) is usually severe and difficult to manage, and insufficient pain relief may delay recovery. The most effective pain treatment has traditionally been epidural analgesia or femoral nerve block (Singelyn et al. 1998, Ganapathy et al. 1999, Chelly et al. 2001, Davies et al. 2004, Ilfeld et al. 2006) in combination with opioid analgesics and non-steroidal anti-inflammatory drugs (NSAIDs, cyclooxygenase (cox) inhibitors). Each of these methods has its specific side effects. Urinary retention and muscular weakness are often reported after epidural analgesia. Unpleasant numbness of a large part of the lower extremity is common after femoral block. Opioid analgesics often cause sedation, nausea and vomiting, and also urinary retention. Non-selective cox inhibitors may cause gastrointestinal bleeding, renal complications, and epidural hematoma, especially in combination with anti-thrombotic prophylaxis with low-molecular-weight heparin (Afzal et al. 2006).An alternative method for postoperative pain relief after TKA, which has attracted growing interest in recent years, is multimodal wound infiltration analgesic technique consisting of peri- and intraarticular infiltration of local anesthetics and NSAID in the knee (LIA) (Andersen et al. 2008a, b, Kerr and Kohan 2008). This technique appears to offer several advantages over traditional methods, since the analgesia affects only the surgical area with limited interference of the muscle strength. Thus, easier rehabilitation of the operated extremity and earlier discharge from the hospital can be expected (Reilly et al. 2005, Essving et al. 2009). Furthermore, recent studies have shown that the LIA technique reduces the requirement for postoperative analgesia with opioids (Tanaka et al. 2001, Busch et al. 2006, Vendittoli et al. 2006).Only a few investigators have randomly compared LIA with other methods with proven analgesic effect, such as femoral block or epidural analgesia (Parvataneni et al. 2007, Toftdahl et al 2007). Parvatanemi and collaborators (2007) have shown that a combination of a femoral block and local administration of bupivacaine, morphine, and epinephrine results in better pain relief and patient satisfaction than femoral block. Toftdahl and collaborators (2007) presented data suggesting that LIA with ropivacaine, ketorolac, and epinephrine results in faster postoperative activation, as indicated by being better able to walk more than 3 m on the first postoperative day as compared to femoral block. A retrospective comparison (DeWeese et al. 2001) indicated that epidural anesthesia with fentanyl and bupivacaine resulted in better pain relief and less use of other analgesics than did continuous infiltration of the knee with bupivacaine.Femoral block is known to be an effective pain treatment after TKA (Szczukowski et al. 2004, Navas et al. 2005, Duarte et al. 2006). We compared the LIA technique with femoral block regarding efficacy of pain management at rest and upon movement after TKA. We also investigated whether LIA reduced the demand for intravenous morphine, administered via a patient-controlled analgesia (PCA) pump during the first 24 h postoperatively.