Background: Knee varus alignment represents a notorious cause of knee osteoarthritis. It can be caused by tibial deformity, combined tibial–femoral deformity and/or ligament imbalance. Understanding malalignment is crucial in total knee arthroplasty to restore frontal plane neutral mechanical axis. The aim of this study was to determine which factor contributes the most to varus osteoarthritic knee and its related surgical implications in performing a total knee arthroplasty. Methods: We retrospectively evaluated 140 patients operated for total knee arthroplasty due to a varus knee. Full-leg hip to ankle preoperative X-rays were taken. Radiological parameters recorded were: mechanical axis deviation, hip–knee–ankle, anatomical–mechanical angle, medial neck shaft angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), lateral proximal femoral angle, lateral distal tibial angle (LDTA), femoral bowing, and length of tibia and femur. We also determined ideals tibial and femoral cuts in mm according to mechanical alignment technique. A R2 was calculated based on the linear regression between the predicted values and the observed data. Results: The greatest contributor to arthritic varus (R = 0.444) was MPTA. Minor contributors were mLDFA (R = 0.076), JLCA (R = 0.1554), LDTA (R = 0.065), and femoral bowing (R = 0.049). We recorded an average of 7.6 mm in lateral tibial cut thickness to restore neutral alignment. Conclusions: The radiological major contributor to osteoarthritic varus knee alignment is related to proximal tibia deformity. As a surgical consequence, during performing total knee arthroplasty, the majority of the correction should therefore be made on tibial cut.

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.

Introduction: Total hip arthroplasty (THA) performed for femoral neck fractures (FNFs) is becoming a more frequent treatment in the active elderly population. Since there is limited research available presenting clinical outcomes after THA using the anterior-based muscle sparing (ABMS) approach, the aim of this study was to compare this surgical approach to the direct lateral (DL) approach in patients treated by THA for FNFs. Materials and Methods: We retrospectively reviewed the data prospectively collected as a part of our “Hip Fracture Unit” and included 163 patients who underwent THA from January 2016 to January 2019 for acute displaced FNFs. Results: A total of 132 patients who completed a minimum 2-years follow up (69 in the ABMS group and 63 in DL group) were included. The ABMS group demonstrated significantly shorter time to reach milestone for hospital discharge (1.5 Days vs 2.1 days, P = .018), while no statistically significant differences were detected in peri-operative complications. At 3 months, the timed up and go test, the Harris Hip Score (HHS) and the Oxford ip Score (OHS) were significantly better ( P = .024, .032 and .034, respectively) in the ABMS group compared to the DL group. No differences were found in functional outcomes (HHS and OHS) nor in complication rate at 6, 12 and 24 months. Discussion: This is one of the first studies to analyze functional results of THA performed for FNFs through an ABMS approach. Results are in line with those already present in the Literature. Conclusion: ABMS approach allows earlier mobilization and better early functional outcomes, compared to DL approach, in patients undergoing THA for acute displaced FNF. No differences are found after 6 months in functional results and complications rate.

Objectives: This study aims to evaluate the patellar height changes after distal femur (DF) endoprosthetic replacement (EPR) and its impact on anterior knee pain (AKP) and range of motion (ROM). Methods: A retrospective review of three institutions’ databases was performed. The patellar height was determined using the modified Insall–Salvati ratio (MIS), the Blackburne–Peel (BP) and the Caton–Deschamps (CD) indexes. Data regarding AKP and ROM were collected. Results: A total of 199 patients were included. The mean age at presentation was 37.9 ± 23.1 years. The mean one-year follow-up MIS, BP and CD were 1.52 (sd: 0.41), 0.82 (sd: 0.33) and 0.93 (sd: 0.33). Patellar height decreased significantly compared to the pre-operative values according to all three scores (p < 0.001). AKP was reported by 34 (17.1%) patients at 1 year follow-up. Patients with patella baja (MIS < 1.2) or pseudo patella baja (CD < 0.6) had a higher incidence of AKP (p = 0.037 and p = 0.024, respectively). The mean flexion ROM was 91°, with a direct correlation with patellar height (MIS p = 0.020, BP p = 0.036 and CD p = 0.036). Conclusion: The restoration of the native position of the joint line in DF EPR is important to maintain optimal patellofemoral biomechanics. Despite surgeons’ tendency toward a reduction in patellar height with respect to pre-operative values, an increase in patellar height might help to achieve better knee flexion and reduce AKP.

Background: Patients affected by chronic kidney disease (CKD) are at increased risk of periprosthetic joint infection (PJI) after total hip arthroplasty (THA). This patient population has a higher risk of recurrent infections and hospitalization. The aim of this study is to compare the profile of microorganisms in patients with CKD and PJI of the hip versus controls and to individuate potentially unusual and drug-resistant microorganisms among the causative bacteria. Materials and methods: A total of 4261 patients affected by PJI of the hip were retrospectively studied. Patients affected by CKD in this population were identified and compared with a control group of patients with PJI but without CKD. Data on patient characteristics and comorbidities were collected. The microorganisms responsible for PJI were identified and compared between both groups. Results: The CKD group included 409 patients, 54.3% male, mean age of 73.8 ± 8.9 years, a higher body mass index (BMI) than the general population (29.88 ± 5.90 kg/m²), and higher age-adjusted CCI of 6.15 ± 2.35. Overall, 70 different isolates of microorganisms were identified, including 52 Gram-positive spp., 28 Gram-negative spp., 3 fungi, and 1 mycobacterium. Polymicrobial infections were more common in CKD group than controls (47.9% versus 30.9%; p < 0.0001). Staphylococcus spp. were the most common bacteria in both groups, followed by Gram-negative Enterobacteriaceae and Streptococcus spp. CKD group showed a higher risk of developing infections caused by Staphylococcus aureus (p = 0.003), Gram-negative bacteria, and Candida (p = 0.035). Conclusions: Renal failure exposes patients who undergo THA to PJI caused by microorganisms that are potentially more drug resistant, leading to a higher risk of treatment failure. Knowing in advance the different microorganism profiles could help to plan a different surgical strategy. Level of Evidence III.

Background: We created a multicenter survey for Italian orthopedic surgeons on how they approach leg length discrepancy (LLD) when dealing with primary total hip arthroplasty. Aim of the study was to show how surgeons manage LLD and follow the literature recommendations during clinical practice. Methods: The survey was composed of 25 questions divided into four sections: 1—surgeon’s profile, 2—preoperative and 3—intraoperative evaluation, and 4—postoperative management. In this paper, we report results to answer Sects. 1 and 2. Absolute and relative frequencies of answers to Sects. 2 and 3 are reported. We divided the participants in subgroups based on the “surgeon’s profile” and evaluated difference in the answers given. Results: Absolute and relative frequencies demonstrate low agreement among participants in all phases of LLD management. We demonstrated a statistically significant difference based on the surgeon’s profile regarding these questions: radiographic measure of LLD depending on working experience, p = 0.008; digital planning based on surgeons’ age, p < 0.001, and workplace, p = 0.026; intraoperative anatomical landmarks based on numbers of procedures per year, p = 0.020; and use of intraoperative X-rays based on working experience, p = 0.002. Conclusions: LLD is a debated topic with no definitive recommendations. Many decisions still depend on tradition and surgeons’ preference.