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.     

Cementless Revision TKA with Bone Grafting of Osseous Defects Restores Bone Stock with a Low Revision Rate at 4 to 10 years

Background  

Addressing bone loss in revision TKA is challenging despite the array of options to reconstruct the deficient bone. Biologic reconstruction using morselized loosely-packed bone graft potentially allows for augmentation of residual bone stock while offering physiologic load transfer. However it is unclear whether the reconstructions are durable.     

Are Barbed Sutures Associated With 90-day Reoperation Rates After Primary TKA?

Background

Studies have suggested that barbed sutures for wound closure in TKAs are an acceptable alternative to standard methods. However others have observed a higher risk of wound-related complications with barbed sutures.

Questions/Purposes

(1) Do 90-day TKA reoperation rates differ between patients undergoing a barbed suture arthrotomy closure compared with a traditional interrupted closure? (2) Do the 90-day reoperation rates of wound-related, deep infection, and arthrotomy failure complications differ between barbed suture and traditional closures?

Methods

A retrospective analysis of a longitudinally maintained institutional primary TKA database was conducted on all TKAs performed between April 2011 and September 2015. We compared 884 primary TKAs, where the arthrotomy was closed with a barbed suture, with 1598 primary TKAs closed with the standard interrupted suture. After barbed sutures were introduced at our institution in 2012, the majority of surgeons gradually switched to barbed suture closures, with many using them exclusively by the end of the data collection period. We confirmed in-person followups and available data past 90 days for 97.4% (1556 of 1598) of the knees in patients with standard sutures and 94.8% (838 of 884) of the knees in patients with barbed sutures. Our primary endpoint was all-cause 90-day reoperation; our secondary endpoints considered: wound-related reoperation, as defined by previous studies; deep infection per Musculoskeletal Infection Society guidelines; and arthrotomy failure, defined intraoperatively as an opening or dehiscence through the previous arthrotomy closure. T tests and chi-square analyses were used to determine differences between the suture cohorts, and bivariate logistic regression was used to determine associations with our 90-day reoperation outcomes.

Results

With the numbers available, there was no association between suture type and 90-day all-cause reoperation (odds ratio [OR], 1.70; 95% CI, 0.82–3.53; p = 0.156). Suture type was not associated with wound-related reoperation (OR, 2.73; 95% CI, 0.97–7.69; p = 0.058). A 0.6% (five of 884) arthrotomy failure rate was observed in the barbed cohort while no (0 of 1598) arthrotomy failures were noted in the traditional group (p = 0.003). Deep infections were rare in both groups (two of 884 barbed sutures, 0 of 1598 standard sutures) and could not be compared.

Conclusions

Although we saw no difference in overall and wound-related 90-day reoperation rates by suture type with the numbers available, we observed a higher frequency in our secondary question of arthrotomy failures when barbed sutures are used for arthrotomy closure during TKA. Given the widespread use of this closure technique, our preliminary pilot results warrant further investigation in larger multicenter cohorts.

Level of Evidence

Level III, therapeutic study.

     

Does Using Autograft Bone Chips Achieve Consistent Bone Ingrowth in Primary TKA?

Background  

Cementless fixation remains controversial in TKA due to the challenge of achieving consistent skeletal attachment. Factors predicting durable fixation are not clearly understood, but we presumed bone ingrowth could be enhanced by the quantity of host bone and application of autograft bone chips.     

Does Speed Matter? Revision Rates and Functional Outcomes in TKA in Relation to Duration of Surgery

Longer operative times may be required in complex total knee arthroplasty (TKA), however little is known about outcomes in procedures performed rapidly. We analysed 58,009 primary TKAs from the New Zealand National Joint Registry. The mean surgical duration was 89 minutes, and 50% of procedures lasted between 60 and 89 minutes. There was no difference in adjusted revision rates for groups lasting between 40 and 120 minutes, however procedures lasting > 120 minutes had significantly higher revision rates. There was a higher revision rate in TKAs lasting < 40 minutes (0.71 vs 0.48 revisions per 100 component years) but this was not statistically significant (P = 0.1). For primary TKAs lasting less than 120 minutes, further shortening operative time did not improve outcome, and very rapid procedures (< 40 minutes) may lead to an increased risk of revision.     

What is the Rate of Revision Discectomies After Primary Discectomy on a National Scale?

Clinical Orthopaedics and Related Research® - Lumbar discectomy has been shown to be clinically beneficial in numerous studies for appropriately selected patients. Some patients, however,...     

What Drives Variation in Episode-of-care Payments for Primary TKA? An Analysis of Medicare Administrative Data

Background

Episode-of-care payments are defined as a single lump-sum payment for all services associated with a single medical event or surgery and are designed to incentivize efficiency and integration among providers and healthcare systems. A TKA is considered an exemplar for an episode-of-care payment model by many policymakers, but data describing variation payments between hospitals for TKA are extremely limited.

Questions/purposes

We asked: (1) How much variation is there between hospitals in episode-of-care payments for primary TKA? (2) Is variation in payment explained by differences in hospital structural characteristics such as teaching status or geographic location, patient factors (age, sex, ethnicity, comorbidities), and discharge disposition during the postoperative period (home versus skilled nursing facility)? (3) After accounting for those factors, what proportion of the observed variation remains unexplained?

Methods

We used Medicare administrative data to identify fee-for-service beneficiaries who underwent a primary elective TKA in 2009. After excluding low-volume hospitals, we created longitudinal records for all patients undergoing TKAs in eligible hospitals encompassing virtually all payments by Medicare for a 120-day window around the TKA (30 days before to 90 days after). We examined payments for the preoperative, perioperative, and postdischarge periods based on the hospital where the TKA was performed. Confounding variables were controlled for using multivariate analyses to determine whether differences in hospital payments could be explained by differences in patient demographics, comorbidity, or hospital structural factors.

Results

There was considerable variation in payments across hospitals. Median (interquartile range) hospital preoperative, perioperative, postdischarge, and 120-day payments for patients who did not experience a complication were USD 623 (USD 516-768), USD 13,119 (USD 12,165-14,668), USD 8020 (USD 6403-9933), and USD 21,870 (USD 19,736-25,041), respectively. Variation cannot be explained by differences in hospital structure. Median (interquartile range) episode payments were greater for hospitals in the Northeast (USD 26,291 [22,377-30,323]) compared with the Midwest, South, and West (USD 20,614, [USD 18,592-22.968]; USD 21,584, [USD 19,663-23,941]; USD 22,421, [USD 20,317-25,860]; p < 0.001) and for teaching compared with nonteaching hospitals (USD 23,152 [USD 20,426-27,127] versus USD 21,336 [USD 19,352-23,846]; p < 0.001). Patient characteristics explained approximately 15% of the variance in hospital payments, hospital characteristics (teaching status, geographic region) explained 30% of variance, and approximately 55% of variance was not explained by either factor.

Conclusions

There is much unexplained variation in episode-of-care payments at the hospital-level, suggesting opportunities for enhanced efficiency. Further research is needed to ensure an appropriate balance between such efficiencies and access to care.

Level of Evidence

Level II, economic analysis.

Electronic supplementary material

The online version of this article (doi:10.1007/s11999-015-4445-0) contains supplementary material, which is available to authorized users.     

Are We Appropriately Compensated by Relative Value Units for Primary vs Revision Total Hip Arthroplasty?

Background

Relative value units (RVUs) are used to evaluate the effort required for providing a service to patients in order to determine compensation. Thus, more complicated cases, like revision arthroplasty cases, should yield a greater compensation. However, there are limited data comparing RVUs to the time required to complete the service. Therefore, the purpose of this study is to compare the (1) mean RVUs, (2) mean operative times, and (3) mean RVU/minute between primary and revision total hip arthroplasty (THA) and (4) perform an individualized idealized surgeon annual cost difference analysis.

Is a Revision a Revision? An Analysis of National Arthroplasty Registries’ Definitions of Revision

Background

The reported survival of implants depends on the definition used for the endpoint, usually revision. When screening through registry reports from different countries, it appears that revision is defined quite differently.

Questions/purposes

The purposes of this study were to compare the definitions of revision among registry reports and to apply common clinical scenarios to these definitions.

Methods

We downloaded or requested reports of all available national joint registries. Of the 23 registries we identified, 13 had published reports that were available in English and were beyond the pilot phase. We searched these registries’ reports for the definitions of the endpoint, mostly revision. We then applied the following scenarios to the definition of revision and analyzed if those scenarios were regarded as a revision: (A) wound revision without any addition or removal of implant components (such as hematoma evacuation); (B) exchange of head and/or liner (like for infection); (C) isolated secondary patella resurfacing; and (D) secondary patella resurfacing with a routine liner exchange.

Results

All registries looked separately at the characteristic of primary implantation without a revision and 11 of 13 registers reported on the characteristics of revisions. Regarding the definition of revision, there were considerable differences across the reports. In 11 of 13 reports, the primary outcome was revision of the implant. In one registry the primary endpoint was “reintervention/revision” while another registry reported separately on “failure” and “reoperations”. In three registries, the definition of the outcome was not provided, however in one report a results list gave an indication for the definition of the outcome. Wound revision without any addition or removal of implant components (scenario A) was considered a revision in three of nine reports that provided a clear definition on this question, whereas two others did not provide enough information to allow this determination. Exchange of the head and/or liner (like for infection; scenario B) was considered a revision in 11 of 11; isolated secondary patella resurfacing (scenario C) in six of eight; and secondary patella resurfacing with routine liner exchange (scenario D) was considered a revision in nine of nine reports.

Conclusions

Revision, which is the most common main endpoint used by arthroplasty registries, is not universally defined. This implies that some reoperations that are considered a revision in one registry are not considered a revision in another registry. Therefore, comparisons of implant performance using data from different registries have to be performed with caution. We suggest that registries work to harmonize their definitions of revision to help facilitate comparisons of results across the world’s arthroplasty registries.     

Incidence of Revision after Primary Implantation of the Agility™ Total Ankle Replacement System: A Systematic Review

Revision of failed total ankle replacement remains a challenge with limited information available to guide treatment options. I undertook a systematic review of electronic databases and other relevant sources to identify material relating to the incidence of revision after primary implantation of the Agility? Total Ankle Replacement System. In an effort to procure the highest quality studies available, studies were eligible for inclusion only if they involved patients undergoing primary Agility? Total Ankle Replacement; had evaluated patients at a mean follow-up of 12 months or longer; included details of the revision performed; and included revision etiologies of aseptic loosening, ballooning osteolysis, cystic changes, malalignment, or instability. A total of 14 studies involving 2312 ankles, with a weighted mean follow-up of 22.8 months, were included. Of the 2312 ankles, 224 (9.7%) underwent revision, of which 182 (81.3%) underwent implant component replacement, 34 (15.2%) underwent arthrodesis, and 8 (3.6%) underwent below-knee amputation. No significant effect from the surgeon’s learning curve on the incidence of revision or the type of revision surgery performed was identified. However, excluding the inventor increased the incidence of revision twofold, from 6.6% to 12.2%, and skewed the type of revision away from arthrodesis and toward implant component replacement or below-knee amputation. Regardless, the incidence of revision after primary implantation of the Agility? Total Ankle Replacement System was less than historically reported and amenable to implant component revision more than 80% of the time. However, methodologically sound cohort studies are needed that include the outcomes after revision surgery, specifically focusing on what implant component replacement techniques are effective in enhancing survivorship of these revised implants and the role of custom-stemmed talar and tibial components have in revision of the Agility? Total Ankle Replacement System. A direct comparison of the incidence of revision between the various contemporary total ankle replacement systems in common use is also warranted.     

Are Revision Hip Arthroplasty Patients at Higher Risk for Venous Thromboembolic Events Than Primary Hip Arthroplasty Patients?

Background

The purpose of this study is to determine whether revision total hip arthroplasty (THA) is associated with increased rates of deep vein thrombosis (DVT) and pulmonary embolism (PE) when compared to primary THA.

Do Rerevision Rates Differ After First-time Revision of Primary THA With a Cemented and Cementless Femoral Component?

Background

Worldwide use of cementless fixation for total hip arthroplasty (THA) is on the rise despite some evidence from the world’s registries suggesting inferior survivorship compared with cemented techniques. The patterns of bone loss associated with failed cementless and cemented THAs may prejudice the results of future revision procedures; however, this has not been documented.

Questions/purposes

The purpose of this study was to compare (1) the risk for rerevision of first revision THA; (2) the patterns of femoral bone loss at the time of first revision of primary THA; (3) the reasons for first revision of primary THA; and (4) the time to first revision of primary THA between primary cementless and cemented femoral components.

Methods

Primary THAs with cemented (n = 1791) and uncemented (n = 805) femoral components that subsequently sustained first revision of the femoral component were identified from the Danish Hip Arthroplasty Registry (DHR). As of 2012, 120,988 primary THAs and 19,282 revisions were registered in the DHR with completeness of 97% and 90% for primary and revision THA, respectively. Median followup for revisions of primary THA with cemented and cementless femoral component was 4 years (range, 0–17 years) and 2 years (range, 0–16 years), respectively. Survival of first revision THA, with second revision of the femur as outcome, was evaluated using hazard ratios (HRs) with 95% confidence interval (CI) adjusting for potential confounding. All patient- and surgery-related data are collected from Danish medical databases. Recording of bone defects in the DHR is based on surgeons’ intraoperative findings.

Results

With the numbers studied, we found no differences in the risk of second revision between the overall cohort between cementless and cemented techniques (HR, 1.32; 95% CI, 0.97–1.80; p = 0.076); however, a second revision for any reason was more likely in patients < 70 years old in whom the index arthroplasty was performed using a cementless technique (HR, 1.48; 95% CI, 1.01–2.17; p = 0.046). Increasingly severe femoral bone defects of type II (30% [532 of 1791] versus 13% [104 of 805]; p < 0.001) type III (11% [200 of 1791] versus 2% [12 of 805]; p < 0.001) and type IV (1% [26 of 1791] versus 0.4% [three of 805]; p = 0.016) were more frequent at revisions of cemented femoral components compared with cementless femoral components. Indications for first revision differed between primary cemented and uncemented femoral components, because a larger proportion of cemented femoral components was revised as a result of aseptic loosening compared with cementless femoral components (74% [1329 of 1791] versus 25% [197 of 805]; p < 0.001), whereas a larger proportion of cementless femoral components was revised as a result of a fracture compared with cemented femoral components (46% [371 of 805] versus 10% [168 of 1791]; p < 0.001). Failure before 5 years was more likely in cementless femoral components than cemented femoral components (91% [733 of 805] versus 44% [749 of 1791], p < 0.001).

Conclusions

We found no differences in the risk of second revision in the overall cohort between cementless and cemented techniques; however, we observed an increased risk for rerevision THA performed on patients < 70 years whose index THAs were performed using cementless components when looking at all causes for revision, even after adjusting for the most likely confounding factors. Our data suggest that increased use of cementless fixation in primary THA may lead to inferior survivorship of first revision THA.

Level of Evidence

Level III, therapeutic study.     

Does Metabolic Syndrome Impact the Risk of Reoperation,Revision, or Complication After Primary Total Knee Arthroplasty?

BackgroundMetabolic syndrome (MetS) is an increasingly frequent condition characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study evaluated implant survivorship, complications, and clinical outcomes of primary TKAs performed in patients who have MetS.MethodsUtilizing our institutional total joint registry, 2,063 primary TKAs were performed in patients with a diagnosis of MetS according to the World Health Organization criteria. MetS patients were matched 1:1 based on age, sex, and surgical year to those who did not have the condition. The World Health Organization’s body mass index (BMI) classification was utilized to evaluate the effect of obesity within MetS patients. Kaplan–Meier methods were utilized to determine implant survivorship. Clinical outcomes were assessed with Knee Society scores. The mean follow-up was 5 years.ResultsMetS and non-MetS patients did not have significant differences in 5-year implant survivorship free from any reoperation (P = .7), any revision (P = .2), and reoperation for periprosthetic joint infection (PJI; P = .2). When stratifying, patients with MetS and BMI >40 had significantly decreased 5-year survivorship free from any revision (95 versus 98%, respectively; hazard ratio = 2.1, P = .005) and reoperation for PJI (97 versus 99%, respectively; hazard ratio = 2.2, P = .02). Both MetS and non-MetS groups experienced significant improvements in Knee Society Scores (77 versus 78, respectively; P < .001) that were not significantly different (P = .3).ConclusionMetS did not significantly increase the risk of any reoperation after TKA; however, MetS patients with BMI >40 had a two-fold risk of any revision and reoperation for PJI. These results suggest that obesity is an important condition within MetS criteria and remains an independent risk factor.Level of EvidenceLevel 3, Case-control study.     

Revision unikondylärer Knieprothesen

Despite the good midterm survivorship reported for unicondylar knee arthroplasty, an increase in revision surgery has to be expected due to increased replacement rates. The reasons for failure as well as distribution are different for unicondylar knee arthroplasty compared to total knee arthroplasty. The main reasons for revision are aseptic loosening and the progression of osteoarthritis. In most cases, unicondylar knee arthroplasty will be revised to total knee arthroplasty. To obtain good revision results, the cause of implant failure has to be analysed carefully. In the case of contained bone defects, the reconstruction can be supported with bone grafting. For those cases with uncontained defects, implants with augmentation and, in some cases, stem extensions are needed. The modularity of the revision implant should cover different intraoperative requirements.     

Revision nach unikondylärer Knieprothese

Unicompartmental arthroplasty is an efficient and approved treatment option of unicompartmental arthritis of the knee, being performed with increasing frequency worldwide. Compared to total knee replacement, there are several advantages such as faster recovery, lower blood loss, better functional outcome and lower infection rates. However, higher revision rates are a frequent argument against the use of unicompartmental arthroplasty. The following article gives an overview of failure mechanisms and strategies for revision arthroplasty. This article is based on a selective literature review including PubMed and relevant print media. Our own clinical experience is considered as well.     

复杂膝关节畸形的TKA治疗

目的探讨复杂膝关节畸形行人工全膝关节置换术（TKA）的可行性和手术方法。方法回顾性分析自2000-01—2008-12行TKA的20例（26膝）复杂膝关节畸形伴严重功能障碍患者,经过充分术前准备后,针对不同畸形特点采用不同的截骨矫形方式,并进行相应挛缩软组织松解。内翻畸形以调整胫骨截骨矫正为主,外翻以调整股骨截骨矫正为主,屈曲行调整股骨远端及胫骨后倾截骨,术后加以系统的康复训练。结果本组术后获得1~5年随访,平均矫正内翻畸形15°,外翻畸形10°,屈曲畸形35°。末次随访HSS评分平均（86.5±8.6）分,较术前平均（36.2±15.4）分明显提高,差异有统计学意义（t=-12.812,P〈0.05）。结论复杂膝关节畸形患者行TKA需重视术前评估,并依据膝关节骨质畸形、软组织形成等病理特点,选择针对性的手术方式及系统性的康复训练,最终可获得一个畸形矫正、稳定无痛、功能良好的膝关节。     

What Is the Dislocation and Revision Rate of Dual-mobility Cups Used in Complex Revision THAs?

BackgroundDual-mobility cups have been shown to reduce the dislocation risk after THA. Although dual-mobility cups can be a useful strategy to mitigate against recurrent dislocation after revision surgery, few clinical studies have focused on the results of complex revision THAs with extensive bone and soft-tissue loss or in patients who have undergone more than one previous surgical procedure.Questions/purposes(1) What is the survival free from revision for dislocation of dual-mobility cups used in complex revision THAs? (2) What is the survival free from any dislocation?MethodsBetween January 1, 2009 and December 31, 2013, 327 patients underwent a complex revision THA that included an acetabular revision, defined as preexisting massive bone loss in the acetabulum (at least Paprosky Type 2B) and/or proximal femur (at least Paprosky Type 3), substantial gluteal soft-tissue involvement, at least two previous surgical procedures or a one-stage septic revision, or history of dislocation. All 327 complex revision patients received a dual-mobility cup. Of those, 34% (111) were lost to follow-up before 5 years and were not known to have reached a study endpoint (revision for dislocation, and any dislocation) before then, leaving 216 patients for analysis. For patients with bilateral hip surgeries only the first operated hip was included for analysis. The median (range) follow-up duration was 69 months (60 to 110). The primary endpoint was dislocation or re-revision for dislocation. Fifty-six percent (120 of 216) of the patients were women and 44% (96 of 216) were men. The mean age of the patients was 69 ± 9 years. The patients underwent a median of four surgical procedures (1 to 4) before the index procedure (the revision evaluated in this study). A survival analysis was performed using the Kaplan-Meier method; any dislocation or revision for dislocation was determined as the endpoint.ResultsThe dislocation-free survival rates were 96% (95% confidence interval 92 to 98) at 5 years and 82% (95% CI 72 to 89) at 9 years. The overall dislocation rate was 11% (24 of 216 patients) at the final follow-up interval. Survival free of revision for dislocation was 99% (95% CI 96 to 100) at 5 years and 85% (95% CI 75 to 92) at 9 years.ConclusionsDual-mobility cups used in complex revision THA in this series had a higher rate of dislocation and revision than expected, based on earlier studies of dislocations of these components. Although we believe dual-mobility cups are still the first choice of implant if the patient has instability, these cups should be used cautiously if severe bone loss or soft-tissue involvement is present.Level of EvidenceLevel III, therapeutic study.