Effectiveness of hip or knee replacement surgery in terms of quality-adjusted life years and costs

BACKGROUND: Concurrent head-to-head comparisons of healthcare interventions regarding cost-utility are rare. The concept of favorable cost-effectiveness of total hip or knee arthroplasty is thus inadequately verified. PATIENTS AND METHODS: In a trial involving several thousand patients from 10 medical specialties, 223 patients who were enrolled for hip or knee replacement surgery were asked to fill in the 15D health-related quality of life (HRQoL) survey before and after operation. RESULTS: Mean (SD) HRQoL score (on a 0-1 scale) increased in primary hip replacement patients (n = 96) from 0.81 (0.084) preoperatively to 0.86 (0.12) at 12 months (p < 0.001). In revision hip replacement (n = 24) the corresponding scores were 0.81 (0.086) and 0.82 (0.097) respectively (p = 0.4), and in knee replacement (n = 103) the scores were 0.81 (0.093) and 0.84 (0.11) respectively (p < 0.001). Of 15 health dimensions, there were statistically significant improvements in moving, usual activities, discomfort and symptoms, distress, and vitality in both primary replacement groups. Mean cost per quality-adjusted life year (QALY) gained during a 1-year period was euro 6,710 for primary hip replacement, euro 52,274 for revision hip replacement, and euro 13,995 for primary knee replacement. INTERPRETATION: Hip and knee replacement both improve HRQoL. The cost per QALY gained from knee replacement is twice that gained from hip replacement.     

Comparative outcomes and cost-utility after surgical treatment of focal lumbar spinal stenosis compared with osteoarthritis of the hip or knee—part 1: long-term change in health-related quality of life

Background contextIt is well accepted that total hip and knee arthroplasty (THA/TKA) for osteoarthritis (OA) is associated with reliable and sustained improvements in postoperative health-related quality of life (HRQoL). Although several studies have demonstrated comparable outcomes with THA/TKA after surgical intervention for lumbar spinal stenosis (LSS), the sustainability of the outcome after LSS surgery compared with THA/TKA remains uncertain.PurposeThe primary purpose of this study is to assess whether improvements in HRQoL after surgical management of focal lumbar spinal stenosis (FLSS) with or without spondylolisthesis are sustainable over the long term compared with that of THA/TKA for OA.Study designSingle-center, retrospective, longitudinal matched cohort study of prospectively collected outcomes, with a minimum of 5-year follow-up (FU).Patient samplePatients who had primary one- to two-level spinal decompression with or without instrumented fusion for FLSS and THA/TKA for primary OA.Outcome measuresPostoperative change from baseline to last FU in Short-Form 36 physical component summary (PCS) and mental component summary (MCS) scores among groups was used as the primary outcome measure.MethodsAn age, sex-matched inception cohort of primary one- to two-level spinal decompression with or without instrumented fusion for FLSS (n=99) was compared with a cohort of primary THA (n=99) and TKA (n=99) for OA and followed for a minimum of 5 years. Linear regression was used for the primary analysis.ResultsMean (percent) FUs in months were 80.5+16.04 (79%), 94.6+16.62 (92%), and 80.6+16.84 (85%) for the FLSS, THA, and TKA cohorts, respectively, with a range of 5 to 10 years for all three cohorts. The number of patients who have undergone revision including those lost to FU for the FLSS, THA, and TKA cohorts were n=20 (20.2%, same site [n=7] and adjacent segment [n=13]) requiring 27 operations, n=3 (3%, same site) requiring 5 operations, and n=8 (8.1%, same site) requiring 12 operations, respectively (p<.01). The average time to first revision was 56/65/43 months, respectively. Mean postoperative PCS (p<.0001) and MCS (p<.02) scores improved significantly and were durable for all groups at the last FU. The mean changes from baseline PCS/MCS scores to last FU were 8.5/6.4, 12.3/7.0, and 8.3/4.9 for FLSS, THA, and TKA, respectively. Adjusting for baseline age, sex, body mass index, PCS score, and MCS score, there was a strong trend in favor of greater sustained change in the PCS score of THA over FLSS (p=.07) and TKA (p=.08). No difference was noted for change in PCS score between FLSS and TKA (p=.95). No differences were noted for change in MCS score among all three cohorts (p>.1).ConclusionsSignificant improvements in HRQoL after surgical treatment of FLSS with or without spondylolisthesis and hip and knee OA are sustained for a mean of 7 to 8 years, with a minimum of 5-year FU. Despite a higher revision rate, patients undergoing surgery for FLSS can expect a comparable long-term average improvement in HRQoL from baseline compared with their peers undergoing TKA and to a lesser extent THA.     

Improved Patient-Reported Quality of Life and Hip Function After Cementless 1-Stage Revision of Chronic Periprosthetic Hip Joint Infection

BackgroundLimited information is available on health-related quality of life (HRQoL) and patient-reported hip function following treatment for a chronic periprosthetic hip joint infection. The purpose of this study is to evaluate changes in HRQoL and patient-reported hip function 2 years following a cementless 1-stage revision for chronic periprosthetic hip joint infection.MethodsPatients (n = 52) enrolled in a previously published clinical study on cementless 1-stage revision in chronic periprosthetic hip joint infection prospectively answered the EuroQol-5D, Short-Form Health Survey 36 (SF-36), and Oxford Hip Score preoperatively and at 3, 6, 12, and 24 months follow-up. Results were compared to age-matched and gender-matched population norm.ResultsA significant improvement in HRQoL and patient-reported hip function appeared in the first 3 months after surgery and reached a plateau after 6 months. The patients statistically reached age-matched and gender-matched population norm after 3 to 12 months follow-up on most items, except for Physical Functioning and Social Functioning on the SF-36. The largest effect sizes were found for Oxford Hip Score at 1.8 and for Role Limitation, Physical and Bodily Pain on the SF-36 at 1.5 and 1.6, respectively.ConclusionPatients treated with a cementless 1-stage revision for chronic periprosthetic hip joint infection experienced a marked increase in HRQoL and patient-reported hip function, and matched population norms on many parameters.     

Survivorship and relative risk of revision in computer-navigated versus conventional total knee replacement at 8-year follow-up

Background and purpose — The long-term effects of computer-assisted surgery in total knee replacement (CAS) compared to conventionally operated knee replacement (CON) are still not clear. We compared survivorship and relative risk of revision in CAS and CON based on data from the Norwegian Arthroplasty Register.

Patients and methods — We assessed primary total knee replacements without patellar resurfacing reported to the Norwegian Arthroplasty Register from 2005 through 2014. The 5 most used implants and the 3 most common navigation systems were included. The groups (CAS, n = 3,665; CON, n = 20,019) were compared using a Cox regression analysis adjusted for age, sex, ASA category, prosthesis brand, fixation method, previous surgery, and diagnosis with the risk of revision for any reason as endpoint. Secondary outcomes were reasons for revision and effects of prosthesis brand, fixation method, age (± 65 years), and hospital volume.

Results — Prosthesis survival and risk of revision were similar for CAS and CON. CAS had significantly fewer revisions due to malalignment. Otherwise, no statistically significant difference was found between the groups in analyses of secondary outcomes. Mean operating time was 13?minutes longer in CAS.

Interpretation — At 8 years of follow-up, CAS and CON had similar rates of overall revision, but CAS had fewer revisions due to malalignment. According to our findings, the benefits of CAS at medium-term follow-up are limited. Further research may identify subgroups that benefit from CAS, and it should also emphasize patient-reported outcomes.     

Prolonged enoxaparin therapy to prevent venous thromboembolism after primary hip or knee replacement. A cost-utility analysis.

Background Among patients undergoing elective total hip or knee replacement, prolonged prophylaxis with low-molecular-weight heparin significantly reduces the risk of symptomatic venous thromboembolism. Whether implementing routine prolonged prophylaxis is cost-effective remains uncertain.Methods We performed an economic modeling study to compare the costs and health outcomes of standard (12 days) with prolonged (42 days) enoxaparin prophylaxis against venous thromboembolism after elective total hip and knee replacement. The primary economic perspective was that of a societal healthcare payer, taking Belgium as a case country. We used cost-utility analysis, a form of cost effectiveness analysis in which costs are reported in monetary terms (euros) and health outcomes are converted into quality-adjusted life years (QALYs) gained, thereby incorporating a measure of quality of life (utility) into the health outcomes. Costs for diagnosis and treatment of proximal and distal deep vein thrombosis, pulmonary embolism, postphlebitic syndrome, and major bleeding were obtained from a Delphi panel (orthopaedic surgeons) and the official reimbursement rates (Federal Ministry of Health). QALYs for these health outcomes were based on utility scores as reported in the literature. The main outcome measure was the incremental cost-utility ratio, reported as the incremental cost per quality-adjusted life year gained (euros/QALY). The incremental cost-utility ratio refers to the amount of money needed to produce one additional QALY. We also performed sensitivity analyses on clinical and economic parameters to identify important model uncertainties.Results In the base-case analysis, incremental costs of prolonged prophylaxis amounted to 58 euros and 114 euros per patient, with an additional gain in QALY of 0.0083 and 0.0018 after total hip and knee replacement, respectively. Thus, a strategy of prolonged enoxaparin prophylaxis was associated with a cost-utility ratio of 6,964 euros/QALY and 64,907 euros/QALY after total hip and knee replacement, respectively. This tenfold difference in incremental cost-utility ratios between hip and knee replacement might have important practical implications. According to recent European guidelines, an intervention costing less than 20,000 euros per QALY is said to exhibit strong evidence for adoption, whereas one costing 20,000–100,000 euros exhibits moderate evidence for adoption. By current European guidelines, the cost of 6,964 euros and 64,907 euros per QALY gained would give strong evidence for adoption of prolonged enoxaparin prophylaxis among total hip replacement patients, but moderate evidence for adoption among total knee replacement patients. Sensitivity analyses using 20% changes from the base-case analysis showed this outcome to be robust.Conclusions Our findings indicate that, among patients undergoing elective total hip or knee replacement, prolonged enoxaparin prophylaxis leads to increased health benefits at increased cost. Given the additional costs that healthcare decision makers in Europe are usually prepared to pay for a gain in utility, prolonged prophylaxis with enoxaparin is cost-effective after elective total hip replacement, and our data provide strong evidence for adoption of prolonged enoxaparin prophylaxis after elective total hip replacement.     

Local infiltration analgesia: a technique for the control of acute postoperative pain following knee and hip surgery: A case study of 325 patients

Background?We have developed a multimodal technique for the control of pain following knee and hip surgery, called "local infiltration analgesia" (LIA). It is based on systematic infiltration of a mixture of ropiva-caine, ketorolac, and adrenaline into the tissues around the surgical field to achieve satisfactory pain control with little physiological disturbance. The technique allows virtually immediate mobilization and earlier discharge from hospital.

Patients and methods?In this open, nonrandomized case series, we used LIA to manage postoperative pain in all 325 patients presenting to our service from Jan 1, 2005 to Dec 31,2006 for elective hip resurfacing (HRA), primary total hip replacement (THR), or primary total knee replacement arthroplasty (TKR). We recorded pain scores, mobilization times, and morphine usage for the entire group.

Results?Pain control was generally satisfactory (numerical rating scale pain score range 0–3). No morphine was required for postoperative pain control in two-thirds of the patients. Most patients were able to walk with assistance between 5 and 6 h after surgery and independent mobility was achieved 13–22 h after surgery. Orthostatic hypotension, nausea, and vomiting were occasionally associated with standing for the first time, but other side effects were unremarkable. 230 (71%) of the 325 patients were discharged directly home after a single overnight stay in hospital.

Interpretation?Local infiltration analgesia is simple, practical, safe, and effective for pain management after knee and hip surgery.     

Association of Pain on Hospital Discharge with the Risk of 30-Day Readmission in Patients with Total Hip and Knee Replacement

BackgroundIt is not clear if there is a risk of 30-day readmissions following total hip and knee arthroplasty in patients reporting high levels of pain at hospital discharge. We examined the relationship between post-surgical pain on the day of discharge and 30-day readmission in patients who received total knee and hip arthroplasty.MethodsRetrospective cohort study was conducted of patients who received total knee (n = 155,284) or hip arthroplasty (n = 89,283) from 2011 to 2018 using electronic health records from the Optum database. Four categories of pain at discharge were created, from none to severe. Multivariate logistic regression models to predict 30-day all-cause readmission were adjusted for patient and clinical characteristics and built separately for knee and hip arthroplasty patients.ResultsMean ages for hip and knee patients were 64.4 (standard deviation 11.3) and 65.7 (standard deviation 9.7) years, respectively. The majority of patients were female (hip: 54.4%; knee: 61.5%). The unadjusted rate of 30-day readmission was 3.54% for hip replacement and 3.66% for knee replacement. In models adjusted for patient and clinical characteristics, for patients with total hip replacement, the odds of 30-day readmission for those with severe pain score at discharge vs those with no pain at discharge were 1.60 (95% confidence interval 1.33-1.92). Similarly, readmission likelihood increased as pain at discharge increased (severe pain vs no pain) for patients with total knee arthroplasty (odds ratio 1.38, 95% confidence interval 1.19-1.59).ConclusionOur findings demonstrated that the pain scores on the day of discharge are associated with 30-day hospital readmission.     

Primary total ankle replacement surgery is a cost-effective intervention

AimsThe primary aim was to assess the cost-effectiveness of primary total ankle replacements (PTAR) in the UK. Secondary aim was to identify predictors associated with increased cost-effectiveness of PTAR.MethodsPre-operative and six-month post-operative data was obtained over a 90-month period across the two centres receiving adult referrals in the UK. The EuroQol general health questionnaire (EQ-5D-3L) measured health-related Quality of Life (HRQoL) and the Manchester-Oxford Foot Questionnaire (MOXFQ) measured joint function. Predictors, tested for significance with QALYs gained, were pre-operative scores and demographic data including age, gender, BMI and socioeconomic status. A cost per QALY of less than £20,000 was defined as cost effective.ResultsThe 51-patient cohort [mean age 67.70 (SD 8.91), 58.8% male] had 47.7% classed as obese or higher. Cost per QALY gained was £1669, rising to £4466 when annual (3.5%) reduction in health gains and revision rates and discounting were included. Lower pre-operative EQ-5D-3L index correlated significantly with increased QALYs gained (p < 0.01), all other predictors were not significantly (p > 0.05) associated with QALYs gained.ConclusionsPTAR is a cost-effective intervention for treating end-stage ankle arthritis. Pre-operative EQ-5D-3L was associated with QALYs gained. A pre-operative EQ-5D-3L score of 0.57 or more was not cost effective to operate on.     

A clinical and radiographic 13-year follow-up study of 138 Charnley hip arthroplasties in patients 50–70 years old: Comparison of university hospital data and registry data

Background and purpose?Arthroplasty registers provide rates of implant survival in large populations based on implant revision. In an unrevised prosthesis population, some patients may have implants with clinically poor outcome or radiographic failure. We therefore evaluated medium-term clinical and radiographic results in patients with Charnley hip arthroplasties and compared our results with data from the Norwegian Arthroplasty Register (NAR).

Patients and methods?From 1989 through 1991, 138 Charnley arthroplasties with plain Palacos cement were performed in 123 patients who were 50–70 years old. At follow-up after 13 (12–15) years, 26 patients had died (28 hips). The 84 unrevised patients (93 hips) were interviewed and underwent clinical and radiographic assessment. Prosthesis survival was estimated by the Kaplan- Meier method.

Results?At follow-up, 83% of the patients were completely satisfied with their hip replacement. Mean Harris hip score (HHS) was 83 (SD 15), mean EQ-5D index was 0.75 (SD 0.24) and mean EQ-VAS score was 69 (SD 21). Most clinical assessments had poorer scores for Charnley category C (n = 47) than for Charnley category A + B (n = 46). Function, according to Charnley's modified Merle d'Aubigné and Postel scoring system, was improved compared to preoperative values. The survival at 10 years was 89% (95% CI: 84–95) and at 13 years it was 85% (95% CI: 79–92) with revision for any reason as endpoint. In addition to 20 revised hips, 8 implants were radiographically loose and 13 hips had HHS < 70, giving a clinical success rate of 76%. Only 4 primary operations (0.8%) had not been reported to the NAR, but all revisions had been reported.

Interpretation?Clinical follow-up studies give essential information that is additional to that gained from revision-based outcome studies. To fully appreciate the clinical effectiveness of an implant, specific hip function, patient satisfaction, quality of life, and radiographic analysis must also be considered. The functional status of the patient has an important influence on the clinical outcome after hip replacement.     

Patients Who Have Limited English Proficiency Have Decreased Utilization of Revision Surgeries After Hip and Knee Arthroplasty

BackgroundWhile racial and ethnic disparities are well documented in access to total joint arthroplasty (TJA), little is known about the association between having limited English proficiency (LEP) and postoperative care access. This study seeks to correlate LEP status with rates of revision surgery after hip and knee arthroplasty.MethodsThis was a retrospective cohort study of patients aged ≥ 18 years who underwent either total hip or total knee arthroplasty between January 2013 and December 2021 at a single academic medical center. The predictor variable was English proficiency status, where LEP was defined as having a primary language that was not English. Multivariable regressions controlling for potential demographic and clinical confounders were used to calculate adjusted odds ratios of undergoing revision surgery within 1 and 2 years after primary arthroplasty for patients who have LEP, compared to English proficient patients.ResultsA total of 7,985 hip and knee arthroplasty surgeries were included in the analysis. There were 577 (7.2%) patients who were classified as having LEP. Patients who have LEP were less likely to undergo revision surgeries within 1 year (1.4% versus 3.2%, P = .01) and 2 years (1.7% versus 3.9%, P = .006) of primary TJA. Patients who have LEP had adjusted odds ratios of 0.45 (confidence interval: 0.22-0.92, P = .03) and 0.44 (confidence interval: 0.23-0.85, P = .01) of receiving revision surgery within 1 and 2 years, respectively.ConclusionPatients who have LEP, compared to English proficient patients, were less likely to undergo revision surgeries at the same institution up to 2 years after hip and knee arthroplasty. These findings suggest that patients who have LEP may face barriers in accessing postoperative care.     

Improved results of primary total hip replacement

Background and purpose Over the past 20 years, several changes in treatment policy and treatment options have taken place regarding hip replacement. For this reason, we wanted to investigate the results after hip replacement in terms of revision rate, during a 21-year period among hip replacements reported to the Norwegian Arthroplasty Register.

Methods 110,882 primary total hip replacements were reported to the Norwegian Arthroplasty Register from 1987 through 2007. Risk of revision during the time periods 1993–1997, 1998–2002, and 2003–2007 was compared to that of the reference period 1987–1992. Adjusted Cox regression analyses were performed to compare the risk of revision in different time periods and extended analyses were done to investigate revision within the first postoperative year and after the first year.

Results There was an overall reduced risk of revision in the time periods 1993–1997, 1998–2002, and 2003–2007 compared to the reference period: RR = 0.81 (95% CI 0.77–0.86), 0.51 (CI 0.47–0.55), and 0.77 (CI 0.68–0.85), respectively. The improved results were due to a marked reduction in aseptic loosening of the femoral and acetabular components in all time periods and in all subgroups of prostheses. A change in the timing of revision took place, with more early revisions and fewer late revisions in the later time periods. Revision due to dislocation and infection increased over time.

Interpretation The risk of revision decreased during the study period, due to fewer cases of aseptic loosening of prosthetic components. The best results were obtained with the use of cemented prostheses. Prevention of dislocation and infection should be a major goal in the future, as revision due to these causes increased during the study period.     

Pain threshold correlates with functional scores in osteoarthritis patients

Background and purpose — Pain sensitization may be one of the reasons for persistent pain after technically successful joint replacement. We analyzed how pain sensitization, as measured by quantitative sensory testing, relates preoperatively to joint function in patients with osteoarthritis (OA) scheduled for joint replacement.

Patients and methods — We included 50 patients with knee OA and 49 with hip OA who were scheduled for joint replacement, and 15 control participants. Hip/knee scores, thermal and pressure detection, and pain thresholds were examined.

Results — Median pressure pain thresholds were lower in patients than in control subjects: 4.0 (range: 0–10) vs. 7.8 (4–10) (p = 0.003) for the affected knee; 4.5 (2–10) vs. 6.8 (4–10) (p = 0.03) for the affected hip. Lower pressure pain threshold values were found at the affected joint in 26 of the 50 patients with knee OA and in 17 of the 49 patients with hip OA. The American Knee Society score 1 and 2, the Oxford knee score, and functional questionnaire of Hannover for osteoarthritis score correlated with the pressure pain thresholds in patients with knee OA. Also, Harris hip score and the functional questionnaire of Hannover for osteoarthritis score correlated with the cold detection threshold in patients with hip OA.

Interpretation — Quantitative sensory testing appeared to identify patients with sensory changes indicative of mechanisms of central sensitization. These patients may require additional pain treatment in order to profit fully from surgery. There were correlations between the clinical scores and the level of sensitization.     

Comparative outcomes and cost-utility following surgical treatment of focal lumbar spinal stenosis compared with osteoarthritis of the hip or knee: part 2—estimated lifetime incremental cost-utility ratios

Background contextAlthough total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been widely accepted as highly cost-effective procedures, spine surgery for the treatment of degenerative conditions does not share the same perception among stakeholders. In particular, the sustainability of the outcome and cost-effectiveness following lumbar spinal stenosis (LSS) surgery compared with THA/TKA remain uncertain.PurposeThe purpose of the study was to estimate the lifetime incremental cost-utility ratios for decompression and decompression with fusion for focal LSS versus THA and TKA for osteoarthritis (OA) from the perspective of the provincial health insurance system (predominantly from the hospital perspective) based on long-term health status data at a median of 5 years after surgical intervention.Study design/settingAn incremental cost-utility analysis from a hospital perspective was based on a single-center, retrospective longitudinal matched cohort study of prospectively collected outcomes and retrospectively collected costs.Patient samplePatients who had undergone primary one- to two-level spinal decompression with or without fusion for focal LSS were compared with a matched cohort of patients who had undergone elective THA or TKA for primary OA.Outcome measuresOutcome measures included incremental cost-utility ratio (ICUR) ($/quality adjusted life year [QALY]) determined using perioperative costs (direct and indirect) and Short Form-6D (SF-6D) utility scores converted from the SF-36.MethodsPatient outcomes were collected using the SF-36 survey preoperatively and annually for a minimum of 5 years. Utility was modeled over the lifetime and QALYs were determined using the median 5-year health status data. The primary outcome measure, cost per QALY gained, was calculated by estimating the mean incremental lifetime costs and QALYs for each diagnosis group after discounting costs and QALYs at 3%. Sensitivity analyses adjusting for +25% primary and revision surgery cost, +25% revision rate, upper and lower confidence interval utility score, variable inpatient rehabilitation rate for THA/TKA, and discounting at 5% were conducted to determine factors affecting the value of each type of surgery.ResultsAt a median of 5 years (4–7 years), follow-up and revision surgery data was attained for 85%-FLSS, 80%-THA, and 75%-THA of the cohorts. The 5-year ICURs were $21,702/QALY for THA; $28,595/QALY for TKA; $12,271/QALY for spinal decompression; and $35,897/QALY for spinal decompression with fusion. The estimated lifetime ICURs using the median 5-year follow-up data were $5,682/QALY for THA; $6,489/QALY for TKA; $2,994/QALY for spinal decompression; and $10,806/QALY for spinal decompression with fusion. The overall spine (decompression alone and decompression and fusion) ICUR was $5,617/QALY. The estimated best- and worst-case lifetime ICURs varied from $1,126/QALY for the best-case (spinal decompression) to $39,323/QALY for the worst case (spinal decompression with fusion).ConclusionSurgical management of primary OA of the spine, hip, and knee results in durable cost-utility ratios that are well below accepted thresholds for cost-effectiveness. Despite a significantly higher revision rate, the overall surgical management of FLSS for those who have failed medical management results in similar median 5-year and lifetime cost-utility compared with those of THA and TKA for the treatment of OA from the limited perspective of a public health insurance system.     

Mid-term results of an uncemented tapered femoral stem and various factors affecting survivorship

ObjectiveCLS stem is commonly used today in primary hip arthroplasty, but only a few studies have evaluated their outcome in young high demanding patients. In Indian scenario, many patients require squatting and sitting cross-legged as part of their daily activities placing excessive load on the joint. We evaluated (I) Mid-long term functional and radiological results (II) Influence of age, gender, diagnosis, stem alignment, Canal fill index (CFI) on the outcome (III) Kaplan-Meier survivorship using revision for any reason or for aseptic loosening as an endpoint.MethodsRetrospective evaluation of 64 THA in 54 patients operated between July 2000 to July 2011 using CLS stem was done. Mean follow-up was 10.3 years (5–14.9 years) with 5 patients lost to follow-up and 4 patients died. Mean age at surgery was 46.8 years (18–78 years).ResultsMean Harris hip score was 89.4 (72–100). Thigh pain was present in 4 hips which were not associated with the sizing of the stem (p = .489). Stable fixation by bony ingrowth was seen in 53 hips (96.4%) and by fibrous ingrowth in 2 cases (3.6%) with no case of loosening seen. Stress shielding was seen as Grade II in 17 hips (30.9%), Grade III in 3 hips (5.4%). Pedestal formation was seen in 9 hips (16.4%) which were statistically associated with varus alignment and CFI < 80. No stem revision was performed with stem survivorship of 100%.ConclusionThe mid-term survival rates and good clinical-radiological outcomes of CLS stem in high demanding Indian population were excellent.     

Stainless Steel Femoral Heads Reduce Rate of Revision When Compared to Ion-Implanted Chromium-Cobalt Heads With a Single Cemented Femoral Design: An Analysis of 40,468 Total Hip Replacements From the Australian Orthopedic Association National Joint Replacement Registry

BackgroundIn order to reduce the incidence of total hip joint replacement revision for wear, multiple advanced materials and alloys targeting hip replacement tribology have been introduced. Ion implantation of chromium-cobalt heads is thought to reduce wear due to increased surface hardness and lower friction. These advances in technology result in additional manufacturing costs. However, it is unclear whether these attributes result in a decreased rate of revision for wear and when used with modern highly crosslinked polyethylene (XLPE). The aim of this study is to compare the survivorship of stainless steel and ion-implanted chromium-cobalt femoral heads in order to determine whether ion implantation has a lower risk of revision.MethodsData from the Australian Orthopedic Association National Joint Replacement Registry included all stainless steel and low-friction ion-treated (LFIT) femoral heads used in conjunction with a primary Exeter/Trident hip replacement combination and XLPE liners performed for osteoarthritis. Kaplan-Meier estimates of survivorship were used to describe the time to first revision. Hazard ratios (HRs) from Cox proportional hazard models, with adjustment for age and gender, were used to compare revision rates between the 2 groups.ResultsThere were 40,468 total hip replacements that met the inclusion criteria. Stainless steel heads had a lower revision rate compared to LFIT chromium-cobalt heads (HR 0.87, 95% confidence interval 0.76-1.00, P = .048). The difference in the rate of revision was even greater when 32-mm heads were used (HR 0.72, 95% confidence interval 0.58-0.89, P = .002). There was no difference in revision for loosening between head alloys or when stratified by age.ConclusionGiven the increased costs associated with LFIT implants and the lower rate of revision for stainless steel heads, we recommend the use of a stainless steel heads when using an Exeter/Trident hybrid hip with an XLPE liner.     

Conversion from failed hemiarthroplasty to total hip arthroplasty: A Norwegian Arthroplasty Register analysis of 595 hips with previous femoral neck fractures

Background and purpose?Conversion total hip replacement (THR) is a common procedure after failed hemiarthroplasty, but there have been few reports describing the long-term outcome of this procedure.

Patients and methods?Between 1987 and 2004, 595 THRs were reported to the Norwegian Arthroplasty Register as conversion THR for failed hemiarthroplasty after a femoral neck fracture in patients aged 60 years and older. 122 operations left the femoral stem intact, whereas 473 were converted with exchange of the femoral stem.

Results?We found a lower risk of failure (revision surgery for any reason) for the conversion procedures with stem exchange (RR = 0.4; 95% CI: 0.25–0.81) than for the conversion procedures that retained the femoral stem. For the 473 conversion arthroplasties with exchange of the stem, we found no difference in risk of failure compared to all revision stems in the register, either for the complete prosthesis (RR = 0.8; CI: 0.50– 1.20) or for the stem (RR = 0.9; CI: 0.53–1.59). However, for the 122 conversion procedures in which the femoral stem was retained, we found a significantly increased risk of failure for both the complete prosthesis (RR = 4.6; CI: 2.8–7.6) and for the acetabular cup (RR = 4.8; CI: 2.3–10) compared to primary hip arthroplasties.

Interpretation?Our findings indicate that the seemingly easy operation of implanting an acetabular cup to convert a hemiarthroplasty to a total hip arthroplasty is an uncertain procedure and that the threshold for replacing the stem should be low.     

Morselized bone grafting in revision arthroplasty of the knee: A retrospective analysis of 34 reconstructions after 2–9 years

Background and purpose?Loosening of a total knee replacement may lead to loss of bone, requiring biological reconstruction at revision arthroplasty. Good results have been reported from revision arthroplasty of the hip using impaction bone grafting. We report our results of revision total knee arthroplasty using the same technique.

Patients and methods?We retrospectively analyzed 30 patients (involving 34 knees) with a mean age of 63 (34–81) years who, between 1994 and 2002, underwent revision arthroplasty of the knee using hinge or rotational knee prostheses (Link) and impaction bone grafting. The average follow-up was 4 (2–9) years and included a questionnaire, a clinical examination, and standardized radiographs.

Results?25 patients were satisfied with their results. 10 patients reported no impairment in their activities of daily living attributed to their operation and did not need any walking support. In 5 patients, there were no clear radiographic signs of incorporation of the graft but that did not compromise the outcome. 5 other patients had complications due to aseptic loosening of their prostheses with radiographic failure of the graft, leading to a periprosthetic fracture in 2 cases.

Interpretation?Our results with impaction bone grafting in knee revision arthroplasty appear to be similar to those obtained by the same technique in revision hip surgery.     

初次髋膝关节置换术后静脉血栓发生情况的观察比较

目的 :通过对大样本的初次全髋、膝关节置换术患者的资料进行统计分析,描述初次髋、膝关节术后静脉血栓的发生率及解剖分布。方法:纳入2013年12月至2014年12月行初次全髋、膝关节置换术1 686例患者,其中THA 928例,TKA 758例。所有患者术前、出院前常规行双下肢静脉彩超,术中常规使用抗纤溶药,术后抗凝14 d。统计分析术后血栓发生类型及其解剖分布。结果:初次全髋关节置换术患者928例,30例出现血栓,27例为孤立性肌间静脉血栓,其次为累及腓静脉或胫后静脉的周围性血栓,无中心型血栓发生。初次全膝关节置换术患者758例中,87例出现血栓,81例为周围型血栓,4例为中心型血栓,其余2例为混合型血栓;74例的血栓累及单支静脉,65例累及肌间静脉、4例股静脉、3例胫后静脉、2例浅静脉;13例的血栓累及多支静脉,多累及肌间静脉、胫后静脉、腓静脉、静脉中的2支或3支。对比结果发现,全膝关节置换术后血栓发生率较高,差异有统计学意义(P0.001),且更容易出现中心型血栓及多支静脉受累。结论:在现代血栓预防措施的干预下,初次髋、膝关节置换术后血栓发生率较低,其发生率及解剖分布存在差异。     

Does Aseptic Revision Risk Differ for Primary Total Knee Arthroplasty Patients Who Have and Do not Have a Prior Primary or Revision Arthroplasty?

BackgroundWe sought to evaluate the risk of aseptic revision in total knee arthroplasty (TKA) patients who have and do not have a history of primary or revision arthroplasty of a different major joint.MethodsWe conducted a matched cohort study using data from Kaiser Permanente’s arthroplasty registries. Patients who underwent primary unilateral TKA (index knee) were identified (2009-2018). Two matches based on exposure history were performed: (1) 33,714 TKAs with a history of primary arthroplasty of a different joint (contralateral knee, either hip, and/or either shoulder) were matched to 67,121 TKAs without an arthroplasty history and (2) 597 TKAs with a history of aseptic revision in a different joint were matched to 1,190 TKAs with a history of a prior arthroplasty in a different joint, but without any revision. After the matches were performed, Cox regressions were used to evaluate aseptic revision risk of the index knee using the no history groups as the reference in regression models.ResultsNo difference in aseptic revision risk for the index knee was observed when comparing patients who had a prior primary arthroplasty in a different joint to those who did not have an arthroplasty history (hazard ratio = 0.95, 95% CI = 0.86-1.06). Those patients who did not have any prior aseptic revision history in a different joint had higher risk of aseptic revision in the index knee (hazard ratio = 2.06, 95% CI = 1.17-3.63).ConclusionPatients who had a prior revision history had over a 2-fold higher risk of aseptic revision in the index knee, warranting close surveillance of these patients.Level of EvidenceLevel III.