Lewallen, David G.

We previously reported 5-year results of 57 patients with major acetabular defects (Paprosky 2B through 3B) who underwent full (31) or half (26) cup-cage reconstructions. This study provides an update with 8.8-year mean follow-up. The 10-year cumulative incidence of and survivorship free from revision, reoperation, and complications were estimated. The 10-year cumulative incidence of revision was 14% for full and 12% for half constructs. The incidence of revision for aseptic loosening was 4.3% and 4.6%, respectively. The 10-year survivorship free from aseptic loosening for patients with pelvic discontinuity was 88.9% (95% confidence interval [CI], 70.6% to 100%) and 85.7% (95% CI, 61.8% to 100%), respectively; no patient without pelvic discontinuity required revision for aseptic loosening. The 10-year cumulative incidence of complications was 42% for all patients, including a 15% incidence of dislocation. Thus, both full and half cup-cage constructs provided durable fixation for complex acetabular bone loss at 10 years, although dislocation remains a concern. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

AimsCeramic-on-ceramic (CoC) articulations in total hip arthroplasty (THA) have the advantage of low wear but the unique risk of fracture. After revision for CoC-bearing fracture, third-body ceramic particles can lead to massive wear of cobalt-chrome (CoCr) bearings, causing extremely elevated blood cobalt. We present a multicentre series of five cases where patients sustained fractures of ceramic liners, were revised using a CoCr articulation, and rapidly developed severe cobalt toxicity.MethodsWe identified five cases of cobalt toxicity after fractured CoC THA treated with revision to CoCr on polyethylene bearings. Mean follow-up was three years (5 to 72 months) after re-revision to remove the CoCr bearing.ResultsSymptoms of cobalt toxicity occurred at a mean ten months (6 to 12) after revision for ceramic fracture. All patients developed vision and hearing loss, balance difficulties, and peripheral neuropathy. Several had cardiomyopathy, endocrine abnormalities, and local skin discolouration. Only two reported hip pain. Repeat revision for recognized cobalt toxicity occurred at a mean 22 months after revision for ceramic fracture. Mean serum cobalt level at re-revision was 991 ng/ml (normal value < 1 ng/ml; 734 to 1,302). All CoCr femoral heads exhibited massive wear, and deep tissues showed prominent metal staining. Treatment consisted of debridement and revision to a ceramic femoral head with highly cross-linked polyethylene (HXLPE) liner. Serum cobalt improved to a mean 25 μg/l (1 to 76) at final follow-up. All patients reported partial improvement in vision and hearing, however their peripheral neuropathy and balance difficulties did not recover.ConclusionSystemic cobalt toxicity is a devastating complication of ceramic-bearing fracture in THA treated with CoCr bearings, which may not present with hip symptoms. The diagnosis of this syndrome of systemic cobalt toxicity was significantly delayed following systemic symptoms in this series. Debridement and re-revision to a ceramic-on-HXLPE bearing leads to improvement, but not full resolution, of cobalt toxicity complications.Cite this article: Bone Joint J 2025;107-B(6 Supple B):92–100.

Aims An angular proximal femoral deformity, in association with osteoarthritis (OA) of the hip, considerably increases the technical complexity of primary total hip arthroplasty (THA). The aims of this study were to determine the long-term implant survival, the risk factors for failure, complications, and clinical outcomes of contemporary primary THA in this difficult group of patients. Methods Our institutional total joint registry was used to identify 119 primary THAs performed in 108 patients with an angular proximal femoral deformity, between January 1997 and September 2017. The deformity was related to a previous femoral osteotomy in 102 THAs (86%), and developmental or metabolic disorders in 17 THAs (14%). A total of 62 hips (53%) had a predominantly varus deformity. The mean age of the patients was 44 years (SD 13), their mean BMI was 29 kg/m 2 (SD 6), and 70 (59%) were female. An uncemented femoral component with metaphyseal fixation was used in 35 THAs (30%), an uncemented femoral component with diaphyseal fixation in 34 (29%), an uncemented modular femoral component with a metaphyseal fixation sleeve in 29 (24%), and a cemented femoral component in 21 (18%). Simultaneous corrective femoral osteotomy was performed in 22 THAs (18%). Kaplan-Meier survival and Harris Hip Scores (HHSs) were reported. The mean follow-up was eight years (2 to 22). Results The ten-year survival free of femoral loosening, any femoral revision, any revision and any reoperation was 95%, 93%, 90%, and 88%, respectively. A total of 13 revisions were undertaken, for aseptic femoral loosening in three, fracture of the femoral component in two, dislocation in two, aseptic acetabular loosening in two, polyethylene liner exchange in two, and infection in two. A preoperative varus deformity was associated with a higher risk of any revision (hazard ratio (HR) 12.5, p = 0.020), and those with a simultaneous osteotomy had a higher risk of any reoperation (HR 3.6, p = 0.023). The mean HHSs improved significantly from 52 preoperatively to 82 at ten years (p < 0.001). Conclusion In the largest series to date of primary THAs in patients with hip OA and an angular proximal femoral deformity, we found a good ten-year survival free from any revision. Varus deformities, particularly those treated with a simultaneous osteotomy due to the magnitude or location of the deformity, had a higher rate of further surgery. Cite this article: Bone Joint J 2025;107-B(6 Supple B):101–108.

Background: Traditional Medicare (TM) claims data are widely used by researchers and registries to report survivorship following total knee arthroplasty (TKA). The purpose of the present study was to investigate whether the mass exodus of patients from TM to Medicare Advantage (MA) has compromised the fidelity of TM data. Methods: We identified 11,717 Medicare-eligible patients (15,282 knees) who had undergone primary TKA from 2000 to 2020 at a single institution. Insurance type was analyzed, and 84% of TKAs were covered by TM. The rates of survivorship free from revision or reoperation were calculated for patients with TM coverage. The same survivorship end points were recalculated after censoring of patients who transitioned to MA after primary TKA, thereby modeling the impact of losing patients from the TM dataset. Differences in survivorship were compared. The mean duration of follow-up was 10 years. Results: From 2000 to 2020, there was a decrease in TM insurance (from 94% to 68%) and a corresponding increase in MA insurance (from 0% to 19%) among patients undergoing TKA. Following TKA, 25% of patients with TM coverage switched to MA. For patients with TM at the time of surgery, the 15-year rates of survivorship free from any reoperation or revision were 90% and 96%, respectively. When patients were censored upon transition from TM to MA, the 15-year rates of survivorship free from any reoperation (92% versus 90%; hazard ratio [HR] = 1.2; p = 0.001) or any revision (97% versus 96%; HR = 1.3; p = 0.002) were significantly higher. Conclusions: One in 4 patients left TM for MA after primary TKA, effectively making them lost to follow-up within TM datasets. The mass exodus of patients out of TM resulted in falsely elevated estimates of survivorship free from reoperation and from revision, with increasing divergence in survivorship over time, when MA data were excluded. As MA continues to grow, efforts to incorporate these data will become increasingly important. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background Debridement, antibiotics, and implant retention (DAIR) is used to manage acute periprosthetic joint infections (PJIs) after total joint arthroplasty (TJA). Given the uncertain success of single or multiple DAIR attempts and possible long-term deleterious effects this treatment can create when trying to treat persistent infection, it is important to understand the frequency with which surgeons in the United States are attempting multiple debridements for PJI and whether those procedures are achieving the desired goal. Question/purposes In the context of the American Joint Replacement Registry (AJRR), we asked: (1) What proportion of patients who undergo DAIR have only one DAIR, and what percentage of those patients have more than one? (2) Of the patients who undergo one or more DAIR procedures, what is the proportion who progress to additional surgical procedures? (3) What is the cumulative incidence of medical or surgical endpoints related to infection on the affected leg (other than additional DAIR procedures)? Methods DAIR procedures to treat PJI, defined by ICD-9/10 and CPT (Current Procedural Technology) codes, reported to the AJRR from 2012 to 2020 were merged with Centers for Medicare and Medicaid Services (CMS) data from 2012 to 2020 to determine the incidence of patients aged 65 and older who underwent additional PJI-related procedures on the same joint. Linking to CMS ensures no loss to follow-up or patient migration to a non-AJRR site. As of 2021, the AJRR captures roughly 35% of all arthroplasty procedures performed in the United States. Of the total 2.2 million procedures in the AJRR, only 0.2% of the procedures were eligible based on our inclusion criteria. Additionally, 61% of the total population is Medicare eligible, and thus, these patients are linked to CMS. Of the 5029 DAIR attempts after a TKA, 46% (2318) were performed in female patients. Similarly, there were a total of 798 DAIR attempts after a THA, and 50% (398) were performed in female patients. For the purposes of decreasing confounding factors, bilateral THAs and TKAs were excluded from the study population. When querying for eligible procedures from 2012 to 2020, the patient population was limited to those 65 years and older, and a subsequent reoperation for infection had to be reported after a primary TJA. This limited the patient population as most infections reported to AJRR resulted in a revision, and we were searching for DAIRs. Although 5827 TJAs were identified as a primary TJA with a subsequent infectious event, more than 65% (3788) of that population did not have a reported event. The following conditions were queried as secondary outcomes after the first DAIR: sepsis, cellulitis, postoperative infection, endocarditis, amputation, knee fusion, resection, drainage, arthrotomy, and debridement. To answer our first and second study questions, we used frequency testing from the available AJRR data. Because of competing risks and issues with incomplete data, we used the cumulative incidence function to evaluate the outcomes specific to study question 3. Results Of the patients who underwent DAIR, 93% (5406 of 5827) had one DAIR and 8% (421 of 5827) had more than one. Among the DAIR population, at least 35% of TKAs and 38% of THAs were identified as having experienced an additional PJI-related event (an additional surgical procedure on the same joint, sustained an infectious endpoint in the linked CMS-AJRR dataset, or they had died). The cumulative incidence of developing a further medical or surgical condition related to the joint that had the initial DAIR were as follows: 48% (95% CI 42% to 54%) at 8 years after a DAIR following a TKA and 42% (95% CI 37% to 46%) at 4 years after a DAIR following a THA. The timepoints for TKA and THA are different because there are more longitudinal procedure data available for TKAs regarding DAIR procedures than for THAs. Conclusion In this study, we used data from the AJRR to assess the incidences of single and multiple DAIR attempts and additional surgical- and infection-related sequalae. Continued investigation is required to determine the fate of infected joints that undergo DAIR with regard to ultimate patient outcome. Future cross-sectional studies using large datasets are necessary to assess functional outcomes and determine the risk of persistent infection after DAIR more precisely. Level of Evidence Level III, therapeutic study.

Angular proximal femoral deformities increase the technical complexity of primary total hip arthroplasties (THAs). The goals were to determine the long-term implant survivorship, risk factors, complications, and clinical outcomes of contemporary primary THAs in this difficult cohort.Our institutional total joint registry was used to identify 119 primary THAs performed in 109 patients with an angular proximal femoral deformity between 1997 and 2017. The deformity was related to previous femoral osteotomy in 85%, and developmental or metabolic disorders in 15%. 53% had a predominantly varus angular deformity. The mean age was 44 years, mean BMI was 29 kg/m2, and 59% were female. An uncemented metaphyseal fixation stem was used in 30%, an uncemented diaphyseal fixation stem in 28%, an uncemented modular body stem with metaphyseal fixation sleeve in 24%, and a cemented stem in 18%. Simultaneous corrective femoral osteotomy was performed in 18%. Kaplan-Meier survivorships and Harris hip scores were reported. Mean follow-up was 8 years.The 10-year survivorships free of femoral loosening, aseptic femoral revision, any revision, and any reoperation were 95%, 93%, 90% and 88%, respectively. Revisions occurred in 13 hips for: aseptic femoral component loosening (3), stem fracture (2), dislocation (2), aseptic acetabular loosening (2), polyethylene liner exchange (2), and infection (2). Preoperative varus angular deformities were associated with a higher risk of any revision (HR 10, p=0.03), and simultaneous osteotomies with a higher risk of any reoperation (HR 3.6, p=0.02). Mean Harris hip scores improved from 52 preoperatively to 82 at 10 years (p<0.001).In the largest series to date of primary THAs in patients with angular proximal femoral deformities, we found a good 10-year survivorship free from any revision. Varus angular deformities, particularly those treated with a simultaneous osteotomy due to the magnitude or location of the deformity, had a higher reoperation rate.Keywords: Proximal femoral deformity; dysplasia; femoral osteotomy; survivorship; revisionLevel of evidence: Level III, comparative retrospective cohort

Background: Modular fluted tapered (MFT) femoral components are frequently utilized in aseptic revision total hip arthroplasties (THAs). However, long-term follow-up has been limited. The purpose of this study was to update our prior series at long-term follow-up, with specific emphasis on implant survivorship, radiographic results, and complications in a large cohort of aseptic revision THAs using MFT stems. Methods: We retrospectively identified 515 aseptic femoral revisions performed with 2 MFT stem designs in the total joint registry of a single tertiary care academic institution from 1999 to 2013. Serial radiographs were reviewed for subsidence of >5 mm. The mean follow-up (and standard deviation) was 10 ± 5 years (range, 2 to 21 years). A competing risk model accounting for death was utilized. Results: The 15-year cumulative incidence of any revision was 12%. There were 57 revisions, 27 of which involved revision of the fluted tapered component (FTC). Dislocation (n = 19), periprosthetic joint infection (n = 15), and aseptic loosening of the FTC (n = 11) were the most common reasons for revision. The 15-year cumulative incidence of any reoperation was 16%. The 15-year cumulative incidences were 6% for any FTC revision and 2% for FTC revision for aseptic loosening. Stem subsidence of >5 mm occurred in 2% of unrevised cases, and all but 1 stem was stable at the most recent follow-up. Conclusions: This large series of MFT stems used in aseptic revision THAs had a 2% incidence of subsequent revision of the FTC for aseptic loosening at 15 years. Dislocation and infection were the most common reasons for any revision. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: Metaphyseal cones with cemented stems can be successfully utilized in most revision total knee arthroplasties (TKAs). However, if the diaphysis has been previously violated, fixation of the cemented stem, which is important for cone ingrowth and construct survival, can be compromised. The initial results of our novel technique combining diaphyseal impaction bone-grafting with a metaphyseal cone were promising but required additional study. The purpose of the present study was to assess results of this technique in a larger cohort. Methods: A metaphyseal cone combined with diaphyseal impaction grafting and a cemented stem was utilized in 88 revision TKAs at our institution, including 35 from our prior study. The mean age at the time of revision was 67 years, and 67% of patients were male. Patients had had a mean of 4 prior knee arthroplasty procedures. The 2 most common reasons for revision were aseptic loosening (78%) and 2-stage reimplantation for periprosthetic joint infection (PJI) (19%). The mean follow-up was 4 years. Results: At the time of the latest follow-up, no cone-impaction grafting constructs required re-revision for aseptic loosening. Five-year survivorship free from any revision of the cone-impaction grafting construct and free from any reoperation was 95% and 65%, respectively. A total of 25 knees (28%) underwent reoperation, with the 2 most common indications being PJI and periprosthetic fracture. All cones were osseointegrated, and all bone graft appeared stable or incorporated. One patient had radiographic evidence of tibial component loosening despite a well-fixed cone; however, this patient was asymptomatic and had not undergone revision at 9 years. Conclusions: When presented with a sclerotic, polished diaphyseal canal with deficient cancellous bone and concomitant metaphyseal bone loss, our technique of combining diaphyseal impaction grafting with a metaphyseal cone proved extremely durable in this larger series of patients. No cone-impaction grafting constructs required re-revision for aseptic loosening. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

AimsDislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct.MethodsWe identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented cups designed for liner cementing (n = 48; 74%) or retained (n = 17; 26%) acetabular components. Median outer head diameter was 42 mm. Mean age was 69 years (SD 11), mean BMI was 32 kg/m2 (SD 8), and 52% (n = 34) were female. Survival was assessed using Kaplan-Meier methods. Mean follow-up was two years (SD 0.97).ResultsThere were nine cemented DM cup revisions: three for periprosthetic joint infection, three for acetabular aseptic loosening from bone, two for dislocation, and one for a broken cup-cage construct. The two-year survivals free of aseptic DM revision and dislocation were both 92%. There were five postoperative dislocations, all in patients with prior dislocation or abductor deficiency. On radiological review, the DM cup remained well-fixed at the cemented interface in all but one case.ConclusionWhile dislocation was not eliminated in this series of complex revision THAs, this technique allowed for maximization of femoral head diameter and optimization of effective acetabular component position during cementing. Of note, there was only one failure at the cemented interface.Cite this article: Bone Joint J 2024;106-B(4):352–358.

AbstractBackground and ObjectivesRecent studies have reported acceptable outcomes after arthrodesis takedown and conversion to total hip arthroplasty (THA); however, there are no reports on outcomes after oncologic resection, which are inherently complex and may portend poorer outcomes. The purpose of this study was to examine the surgical and functional outcomes of patients who underwent prior hemipelvectomy for tumor resection and were later converted to THA.MethodsAll patients who had prior iliofemoral arthrodesis after oncologic resection that were later converted to THA at a single institution were examined. Charts were reviewed for demographic information, operative information, functional outcomes, and complications/reoperations.ResultsAll three patients in this study were males who underwent internal hemipelvectomies for chondrosarcoma. Patients were converted to THA at a mean of 26 years after arthrodesis. Mean follow‐up after conversion to THA was 7.4 years. During this follow‐up period, two of the three patients required revision surgery. At last follow‐up, the mean Harris Hip Score was 81 and the mean Mayo Hip Score was 67, and all patients were ambulatory without significant pain.ConclusionsOverall, patients who undergo iliofemoral arthrodesis after oncologic hemipelvectomy and are later converted to THA can expect to have a reasonable outcome, despite a high rate of complications and revision surgery.