Different intraoperative joint laxity patterns do not impact clinical outcomes in robotic-assisted medial unicompartmental knee replacement with 1-to-1 surface reconstruction.

PURPOSE: Robotic-assisted technology in medial unicompartmental knee arthroplasty (mUKA) allows for customized adjustments of joint laxity through virtual preoperative component positioning before bone preparation. Nevertheless, the optimal balancing curve has yet to be delineated. This study sought to investigate if varying intraoperative knee laxity patterns had any impact on postoperative patient outcomes. MATERIALS AND METHODS: A retrospective analysis was conducted on prospectively collected data from 326 fixed-bearing RAUKA procedures performed between 2018 and 2022 with a minimum 2-year follow-up. Patients were categorized into three cohorts based on intraoperative joint laxity patterns (millimetres of joint gap during valgus stress) imparted at 20°, 60°, 90° and 120° of knee flexion: cohort 1 < +0.5 mm (tight); cohort 2 between 0.6 and 1.9 mm (physiologic); cohort 3 > 2 mm (loose). Wilcoxon and Kruskal-Wallis tests were conducted to assess patient-reported outcome measure (PROM) improvements and preoperative and postoperative differences across the cohorts. A Spearman's test evaluated the correlation between knee balance at all degrees of flexion and preoperative and postoperative HKA. RESULTS: No differences in preoperative and postoperative PROMs were identified across the cohorts (p > 0.05). All three cohorts with different joint laxity patterns showed a significant improvement in the postoperative PROMS (p < 0.05). The preoperative or postoperative limb alignment did not significantly affect clinical outcomes relative to different laxity patterns. CONCLUSION: No differences were found in the outcomes across different joint laxity patterns in robotic-assisted medial UKA using fixed-bearing mUKAs. There was no evident advantage for maintaining a closer to physiologic laxity compared to tighter or looser balancing. LEVEL OF EVIDENCE: Level III therapeutic study.

Favorable early outcomes of medial unicompartimental knee arthroplasty in active patients presenting a degenerative medial meniscus root tear with meniscal extrusion and mild radiographic osteoarthritis.

INTRODUCTION: There is only limited literature available evaluating the preferable treatment for active mid-age or elderly patients presenting with a degenerative medial meniscus root tear (d-MMRT) with medial meniscal extrusion (MME) and early-phase radiographic osteoarthritis (OA), failing to provide solid evidence. The aim of this study was to evaluate early outcomes of medial unicompartimental arthroplasty (mUKA) in active patients presenting a d-MMRT with meniscal extrusion and mild radiographic OA of the knee. To prove this claim we hypothesized that (1) patients with a d-MMRT with initial grade 1-3 KL OA of the medial compartment of the knee present the same pre-operative symptoms as patients with an end-stage grade 4 K-L OA, and that (2) those patients with d-MMRT and low-grade OA achieve the same early clinical and functional outcomes when treated with mUKA compared to patients with end-stage medial OA. METHODS: We reviewed the prospectively collected data of 185 patients undergoing robotic-assisted image-based mUKA from January 2021 to July 2022 at a single Institution. We identified two different cohorts of non-consecutive patients: a group of 24 patients undergoing mUKA surgery following d-MMRT combined with K-L grades 1-3 OA (group 1), and a group of 161 patients who underwent mUKA but presenting with an end-stage bone-on-bone K-L grade 4 OA (group 2). Preoperative and postoperative clinical assessments at one-year follow-up included the Oxford Knee Score (OKS), 5-level EQ-5D version (EQ-5D-5L score), and a standard weight-bearing X-ray protocol. The paired t-test was used to compare clinical outcomes and radiologic values of the two cohorts and in-between the two cohorts. Statistical significance was set at p < 0.05. RESULTS: The mean follow-up for group 1 was 16.4 ± 2.5 months, and the mean age at the time of operation was 63 ± 8.6 years with a mean time from diagnosis to intervention of 53 ± 47.5 days. Preoperative impairment was greater in group 1 compared to group 2, but with no significant difference. Postoperatively, both groups showed excellent mean outcomes at 1-year follow-up, with no significant difference. The mean preoperative HKA, mPTA, and LDFA were 176.3 ± 3.1, 88.1 ± 2.3, and 86.6 ± 1.7 respectively. The mean postoperative HKA, coronal femoral component angle, and coronal tibial component angle were 179.1 ± 2.6, 87.2 ± 2.3, and 87.2 ± 3.3. No difference was found between preoperative age, BMI, between the two cohorts. CONCLUSIONS: Favorable early clinical outcomes were obtained after mUKA in active mid-age and elderly patients presenting with degenerative medial meniscus root tear and mild isolated medial OA. Patients with mild no bone-on-bone OA but with degenerative medial meniscus root tear and medial meniscal extrusion presented the same or worse pre-operative symptoms as patients with end-stage medial OA and benefit the same from mUKA.

A dual telescoping lag screw nailing system for intertrochanteric fractures: retrospective analysis of clinical and radiologic outcomes.

BACKGROUND AND PURPOSE: The aim of this study was to evaluate whether this system is associated with a reduced rate of failure and complications in patients treated for proximal femoral fractures with intramedullary nailing. MATERIALS AND METHODS: 742 Patients with AO-OTA 31-A intertrochanteric fractures were enrolled at a single Institution. Functional evaluation was assessed through the Functional Independence Measure (FIM™) instrument and Parker's New Mobility Score (NMS). Radiological follow-up included the degree of the reduction according to the Baumgartner criteria, the Tip-Apex Distance, and the shortening of the telescoping screws and its lateral protrusion. RESULTS: Pre-operative mean FIM™ and NMS were 4.3 (range 1-9) and 98.7 (range 22-126), respectively. At the 12-month follow-up the average FIM™ and NMS were 95.3 (range 22-126) and 3.7 (range 1-9), respectively. Mean shortening of the lag screws was 4.3 mm (range 1-8) and mean lateral protrusion was 1.7 mm (range 0-3). 3 Cases (0.70%) of non-consolidation requiring reoperation were recorded. 1 Case (0.24%) of these cases was also characterized by nail breakage. No case of cut-out has been reported at our follow-up. CONCLUSIONS: This dual telescoping nail system is effective and safe. The sliding of the telescoping screws within the barrel is able to decrease strain from the femoral head during weight bearing reducing the risk of cut-out.

Techniques for abductor reattachment in proximal femoral replacement for non-oncological reconstructions: a narrative review.

Background and Objective: Proximal femoral replacement due to revision hip arthroplasty or catastrophic proximal femur fracture fixation failures with considerable proximal femur bone loss can lead to a substantial loss of function of the soft tissue around the hip and the abductor muscles in particular. Surgical techniques of gluteus medius repair and/or abductor mechanism reattachment/reconstruction are widely debated in the literature, but it is quite rarely dealt with in the context of megaprosthesis and femoral reconstruction, particularly in non-oncologic patients. The aim of this study is to present a narrative review of the literature on techniques for abductor reattachment in proximal femoral replacement for non-oncological reconstructions. Methods: MEDLINE, Embase, and Cochrane databases were searched by two researchers independently from inception until February 1st, 2023 (923 for MEDLINE and 963 for Embase; Cochrane is a composite of multiple databases and thus does not report a standard inception date). Articles examining proximal femoral reconstruction with megaprosthesis or allograft prosthesis were included. Studies concerning cadaver and oncologic patients were excluded. If the researchers failed to find an agreement on whether to include a study, the senior researcher would make a final decision in such cases. Data were extracted and stored, and qualitative synthesis was performed. Key Content and Findings: A total of 1,157 articles from MEDLINE, 11,187 articles from Embase, and 0 articles from Cochrane were identified. Of 12,344 articles, the structured screening process revealed 10 eligible trials. Four different types of abductor musculature reconstruction/reinsertion were identified. Conclusions: Multiple and complex revision hip arthroplasties as well as multiple surgical procedures for proximal femur fracture fixations failures may have a great impact on proximal femur bone stock condition and soft tissue preservation requiring the use of a proximal femur megaprosthesis. In such cases, the abductor mechanism reconstruction and/or reattachment is achievable with different techniques that can be resumed in four different groups: direct suture to the prosthesis, trochanteric sleeve osteotomy, muscle-to-muscle suture, and synthetic tube augmentation suture.

Learning curves for high tibial osteotomy using patient-specific instrumentation: a case control study.

Objectives: Three-dimensional (3D) planning and Patient Specific Instrumentation (PSI) can help the surgeon to obtain more predictable results in Medial Opening Wedge High Tibial Osteotomy (mOW-HTO) than the conventional techniques. We compared the accuracy of the PSI and standard techniques and measured the learning curve for surgery time and number of fluoroscopic shots. Methods: We included the first 12 consecutive cases of mOW-HTO performed with 3D planning and PSI cutting guides and the first 12 non-supervised mOW-HTO performed with the standard technique. We recorded surgery time and fluoroscopic time. We calculated the variation (Δ delta) between the planned target and the postoperative result for Hip Knee Ankle Angle (HKA), mechanical medial Proximal Tibia Angle (MPTA), Joint Line Convergence Angle (JLCA) and tibial slope (TS) and compared it both groups. We also recorded the complication rate. We then calculated the learning curves for surgery time, number of fluoroscopic shots, Δ from target in both groups. CUSUM analysis charts for learning curves were applied between the two groups. Results: Mean surgical time and mean number of fluoroscopic shots were lower in PSI group (48.58±7.87 vs. 58.75±6.86 min; p=0.034 and 10.75±3.93 vs. 18.16±4.93 shots; p<0.001). The postoperative ΔHKA was 0.42±0.51° in PSI vs. 1.25±0.87° in conventional, p=0.005. ΔMPTA was 0.50±0.67° in PSI vs. 3.75±1.48° in conventional, p<0.001; ΔTS was 1.00±0.82° in PSI vs. 3.50±1.57° in conventional, p<0.001. ΔJLCA was 1.83±1.11° in PSI vs. 4±1.41° in conventional, p<0.001. The CUSUM analysis favoured PSI group regarding surgery time (p=0.034) and number of shots (p<0.001) with no learning curve effect for ΔHKA, ΔMPTA, ΔJLCA and ΔTS. Conclusions: PSI cutting guides and 3D planning for HTO are effective in reducing the learning curves for operation time and number of fluoroscopic shots. Accuracy of the procedure has been elevated since the first cases.

Computer Patient-Specific 3D Modeling and Custom-Made Guides for Revision ACL Surgery.

Revision anterior cruciate ligament reconstruction (ACLR) is a challenging surgery occurring in 3 to 24% of primary reconstructions. A meticulous planning to study the precise size and location of both femoral and tibial bone tunnels is mandatory. The aim of the study was to evaluate the intra- and interoperator differences in the decision-making process between experienced surgeons after they were asked to make preoperative planning for ACL revision reconstruction with the use of both the computed tomography (CT) scan and a three-dimensional (3D)-printed model of the knee. Data collected from 23 consecutive patients undergoing revision of ACLR for graft failure at a single institute between September 2018 and February 2020 were prospectively reviewed. The double-blinded collected data were presented to three board-certificate attending surgeons. Surgeons were asked to decide whether to perform one-stage or two-stage revision ACLR based on the evaluation of the CT scan images and the 3D-printed custom-made models at two different rounds, T0 and T1, respectively, 7 days apart one from the other. Interoperator consensus following technical mistake was 52% at T0 and 56% at T1 using the CT scans, meanwhile concordance was 95% at T0 and 94% at T1 using the 3D models. Concordance between surgeons following new knee injury was 66% at T0 and 70% at T1 using CT scans, while concordance was 96% both at T0 and T1 using 3D models. Intraoperative variability using 3D models was extremely low: concordance at T0 and T1 was 98%. McNemar test showed a statistical significance in the use of 3D model for preoperative planning (p < 0.005). 3D-printed model reliability resulted to be higher compared with CT as intraoperator surgery technique selection was not modified throughout time from T0 to T1 (p < 0.005). The use of 3D-printed models had the most impact when evaluating femoral and tibial tunnels, resulting to be a useful instrument during preoperative planning of revision ACLR between attending surgeons with medium-high workflow.