Osteonecrosis of the Femoral Head: an Updated Review of ARCO on Pathogenesis, Staging and Treatment.

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Isolated tibial insert exchange in revision total knee arthroplasty : reliable and durable for wear; less so for instability, insert fracture/dissociation, or stiffness.

AIMS: This study aimed to determine outcomes of isolated tibial insert exchange (ITIE) during revision total knee arthroplasty (TKA). METHODS: From 1985 to 2016, 270 ITIEs were performed at one institution for instability (55%, n = 148), polyethylene wear (39%, n = 105), insert fracture/dissociation (5%, n = 14), or stiffness (1%, n = 3). Patients with component loosening, implant malposition, infection, and extensor mechanism problems were excluded. RESULTS: Survivorship free of any re-revision was 68% at ten years. For the indication of insert wear, survivorship free of any re-revision at ten years was 74%. Re-revisions were more frequent for index diagnoses other than wear (hazard ratio (HR) 1.9; p = 0.013), with ten-year survivorships of 69% for instability and 37% for insert fracture/dissociation. Following ITIE for wear, the most common reason for re-revision was aseptic loosening (33%, n = 7). For other indications, the most common reason for re-revision was recurrence of the original diagnosis. Mean Knee Society Scores improved from 54 (0 to 94) preoperatively to 77 (38 to 94) at ten years. CONCLUSION: After ITIE, the risk and reasons for re-revision correlated with preoperative indications. The best results were for polyethylene wear. For other diagnoses, the re-revision rate was higher and the failure mode was most commonly recurrence of the original indication for the revision TKA. Cite this article: Bone Joint J 2021;103-B(6):1103-1110.

Biconvex Patellar Components: 96% Durability at 10 Years in 262 Revision Total Knee Arthroplasties.

BACKGROUND: The optimal strategy to address osseous deficiencies of the patella during revision total knee arthroplasty (TKA) remains controversial. One possible solution is a cemented biconvex patellar component used such that the non-articular convexity both improves fixation and makes up for bone loss. The aim of this study was to determine the outcomes of the use of biconvex patellar components in a large series of revision TKAs. METHODS: From 1996 to 2014, 262 revision TKAs were performed at a single institution using a biconvex patellar component. Implant survivorship, clinical and radiographic results, and complications were assessed. The mean patient age at the TKA revision was 69 years, and 53% of the patients were female. The mean follow-up was 7 years. RESULTS: The 10-year survivorship free of revision of the biconvex patellar component due to aseptic loosening was 96%. The 10-year survivorship free of any revision of the biconvex patellar component was 87%. The 10-year survivorship free of any rerevision and free of any reoperation was 75% and 70%, respectively. The mean Knee Society Score (KSS) improved from 45.4 before the index revision to 67.7 after it. The mean residual composite thickness seen on the most recent radiographs was 18.1 mm. In addition to the complications leading to revision, the most common complications were periprosthetic patellar fracture (6%), of which 3 required revision; superficial wound infection (6%) requiring antibiotic therapy only or irrigation and debridement; and arthrofibrosis (3%). CONCLUSIONS: In this cohort of 262 revision TKAs, biconvex patellar components used to treat marked patellar bone loss demonstrated excellent durability with a 10-year survivorship free of patellar rerevision due to aseptic loosening of 96%. The biconvex patellar components were reliable as evidenced by substantial improvements in clinical outcomes scores and a low risk of complications. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Intravenous Tranexamic Acid Safely and Effectively Reduces Transfusion Rates in Revision Total Knee Arthroplasties.

BACKGROUND: The efficacy and safety of tranexamic acid (TXA) in primary total knee arthroplasty (TKA) have been well established. However, there have been limited data for revision TKAs. The primary aim was to assess the impact of intravenous TXA on transfusion rates and symptomatic venous thromboembolic events (VTEs) in a large revision TKA cohort with or without intravenous TXA utilization. METHODS: A retrospective review of revision TKAs performed from 2005 to 2014 was performed, identifying 2,951 procedures (2,219 patients), in which TXA was utilized in 1,144 procedures (39%). The mean age was 65 years with 52% female patients in the TXA revision group and 67 years with 52% female patients in the non-TXA revision group. Transfusion rates and symptomatic VTEs were the primary outcomes assessed. Comparisons were performed between cohorts, utilizing a unique propensity model to mitigate bias, on the basis of TXA use and subsequently for aseptic or septic revision etiology. RESULTS: Significant reductions in transfusion rates with use of TXA were identified in revision TKAs overall (13% compared with 39%; p < 0.001 [adjusted relative risk, 1.7]), including revisions for both aseptic etiology (6% with TXA compared with 28% without TXA; p < 0.001) and septic etiology (31% with TXA compared with 54% without TXA; p < 0.001). The risk of a postoperative symptomatic VTE was not significantly different (adjusted p = 0.63) with use of TXA at 11 events (1.0%) compared with 24 events (1.3%) in the non-TXA group). CONCLUSIONS: Intravenous TXA significantly reduced transfusion rates in revision TKAs by approximately twofold, including cohorts revised for aseptic and septic etiologies. There was a very low rate of VTEs (1.2%) with no significant difference in the number of VTEs between groups after adjusting risk utilizing propensity modeling. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.