Viktor E. Krebs

Background: Cerclage fixation is widely used in total hip arthroplasty (THA) for managing intraoperative and periprosthetic fractures, securing osteotomies, and augmenting fixation in both primary and revision procedures. Despite broad application, the variations in materials, techniques, and outcomes merit evaluation. Methods: This review synthesizes evidence on the evolution of cerclage systems, biomechanical performance, surgical techniques, and complications. Studies of metallic, polymer-based, and hybrid constructs, as well as open versus percutaneous approaches, were critically appraised. Results: Cerclage has evolved from stainless steel to materials like cobalt-chromium, which demonstrates load-to-failure values exceeding 3000 N. Percutaneous techniques show high union rates of 95–100% and higher anatomic reduction. Nonetheless, mechanical failures, metallic debris, infection, and other rare complications remain concerns. Conclusions: Cerclage fixation remains indispensable in THA. Careful implant choice, precise technique, and recognition of complications are essential, while further comparative studies are needed.

Introduction: Patellar management during revision TKA (rTKA) remains challenging. Metal-backed patella (MBP) with highly porous titanium coating applied by 3D printing may provide improved fixation in TKA, especially in patients with limited bone stock. The primary aim of this study was to assess implant survivorship among patients who received a new-generation MBP during revision TKA. Secondary aims were to assess (1) healthcare utilization, and (2) preoperative and 1-year PROMs. Methods: This was a retrospective review of patients who received a MBP during rTKA from 2017 to 2022. In total, 31 patients achieved an average follow-up of 3.0 years (SD 1.5 years). Knee injury and Osteoarthritis Outcome Score (KOOS) Pain, KOOS Physical Function Shortform (PS), KOOS Joint Replacement (JR) and Veterans RAND 12-Item Health Survey Mental Component Score (VR-12 MCS) were obtained preoperatively and at 1-year. Most patients had prior ipsilateral prosthetic joint infection (PJI; n  = 22, 71%). Results: MBP implant survivorship was 96.8%. No patients had evidence of patellar component aseptic loosening. The average patellar thickness was 11.8 mm (SD 2.3 mm). After rTKA, most patients were discharged home following surgery ( n = 24, 77.4%). There were 5 patients (16.1%) readmitted within 90-days, and no deaths within 1-year. Significant improvement was found in KOOS Pain ( p < 0.001), and KOOS JR ( p = 0.005), but not KOOS PS ( p = 0.080) or VR-12 MCS ( p = 0.279). Conclusions: Titanium 3D-printed MBP resulted in excellent implant survivorship with major improvements in pain and overall joint health. Thus, MBP appears to be a viable patellar component option in revision TKA.

Background: There is no foundational classification that 3-dimensionally characterizes arthritic anatomy to preoperatively plan and postoperatively evaluate total knee arthroplasty (TKA). With the advent of computed tomography (CT) as a preoperative planning tool, the purpose of this study was to morphologically classify pre-TKA anatomy across coronal, axial, and sagittal planes to identify outlier phenotypes and establish a foundation for future philosophical, technical, and technological strategies. Methods: A cross-sectional analysis was conducted using 1,352 pre-TKA lower-extremity CT scans collected from a database at a single multicenter referral center. A validated deep learning and computer vision program acquired 27 lower-extremity measurements for each CT scan. An unsupervised spectral clustering algorithm morphometrically classified the cohort. The optimal number of clusters was determined through elbow-plot and eigen-gap analyses. Visualization was conducted through t-stochastic neighbor embedding, and each cluster was characterized. The analysis was repeated to assess how it was affected by severe deformity by removing impacted parameters and reassessing cluster separation. Results: Spectral clustering revealed 4 distinct pre-TKA anatomic morphologies (18.5% Type 1, 39.6% Type 2, 7.5% Type 3, 34.5% Type 4). Types 1 and 3 embodied clear outliers. Key parameters distinguishing the 4 morphologies were hip rotation, medial posterior tibial slope, hip-knee-ankle angle, tibiofemoral angle, medial proximal tibial angle, and lateral distal femoral angle. After removing variables impacted by severe deformity, the secondary analysis again demonstrated 4 distinct clusters with the same distinguishing variables. Conclusions: CT-based phenotyping established a 3D classification of arthritic knee anatomy into 4 foundational morphologies, of which Types 1 and 3 represent outliers present in 26% of knees undergoing TKA. Unlike prior classifications emphasizing native coronal plane anatomy, 3D phenotyping of knees undergoing TKA enables recognition of outlier cases and a foundation for longitudinal evaluation in a morphologically diverse and growing surgical population. Longitudinal studies that control for implant selection, alignment technique, and applied technology are required to evaluate the impact of this classification in enabling rapid recovery and mitigating dissatisfaction after TKA. Level of Evidence: Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Introduction: Total joint arthroplasty (TJA) is evolving with new technologies and techniques introduced in fellowship training, but the effect on surgeons' future practices remains unclear. We assessed current practice patterns and influential factors among fellowship-trained arthroplasty surgeons. Methods: An electronic survey was sent to all currently practicing surgeons (n = 90) who had completed a high-volume adult reconstruction fellowship at a single tertiary academic center from 1986 to 2022. The survey consisted of 73 questions regarding surgeon and practice characteristics for primary and revision total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty. Data were tabulated and analyzed in REDCap software. Results: The survey was completed by 53 surgeons (59%): 46% had been in practice for 0 to 5 years, 32% for 6 to 10 years, and 21% for 11 to 20 years. Overall, 81% performed at least 100 THAs, and 77% performed at least 150 TKAs annually. Revision TJA constituted 0% to 20% of surgical practice for 70% of surgeons, whereas 30% performed revision TJA in 21% to 40% of cases. The most common approach for THA was direct anterior (28/53, 53%), followed by posterior (22/53, 42%). Fellowship experience was the most influential factor on the choice of THA approach (57%), as well as on the choice of THA (64%) and TKA (57%) implants. Among surgeons with access to robots, 52% did not perform any robotic THAs, whereas 27% performed more than 80% of their THAs robotically. By contrast, 64% of surgeons performed more than 80% of their primary TKAs robotically, and only 13% did no robotic TKAs despite having access to a robot. Conclusion: Fellowship experience was the primary factor influencing approach and implant choices in both THA and TKA, highlighting its notable effect on shaping trainees' future practices. Therefore, fellowship programs should offer exposure to diverse technologies and techniques to enable informed decision making.

Background: Return to work (RTW) and sports (RTS) are critical gauges to improvement among patients after total knee arthroplasty (TKA). This study aimed to determine rates, timelines, and prognostic factors associated with RTW and RTS outcomes after primary TKA. Methods: A systematic review was conducted on MEDLINE, Embase, and CENTRAL databases, with 44 studies meeting inclusion/exclusion criteria. The risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions tool. Meta-analysis and pooled analysis were conducted when possible with forest plots to summarize odds ratios and associated 95% confidence intervals (CIs). Results: The pooled RTW rate across all studies was 65% (95% CI, 51%-77%), with rates varying significantly from 10% to 98%. The mean time to RTW was of 12.9 weeks (range, 5-42). A time point analysis showed increasing RTW rates with a maximum rate at 1 year of 90%. Increased age was associated with lower RTW rates (p < 0.001). The RTS rate ranged from 36% to 100%, with a pooled rate of 82% (95% CI, 72%-89%). The mean time to RTS was 20.1 weeks (range, 16-24). A wide range of reported recurrence rates was observed among different sports (subgroup differences, p ≤ 0.001). The RTS ranged from 43% to 98%, with a pooled proportion of 76% (95% CI, 59%-87%, I² = 91%) for low-intensity sports, and from 0% to 55% for high-intensity sports, with a pooled proportion of 35% (95% CI, 20-52, I² = 70%). Conclusion: Most patients successfully return to sports and work after TKA, with rates of RTW increasing to 90% after 1 year. Such outcomes are heavily influenced by nonmodifiable (e.g., age) and modifiable (e.g., intensity of sports/employment) factors. Generally, young adults and patients with low-demand jobs can be reinitiated earlier, albeit with increasing restrictions with rising intensity. Providers should screen patients for desire to RTW and/or RTS after surgery and provide appropriate recommendations as part of necessary preoperative education and postoperative care. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.