Background/Objectives: Symptomatic hardware removal remains the most frequent cause of reoperation after tibial tubercle osteotomy (TTO), with removal rates reported as high as 49%. Headless compression screws have been proposed as a low-profile alternative to conventional screws to reduce hardware-related morbidity, yet no study has directly compared their use with headed screws in TTO for patellofemoral instability. This study aimed to compare complication rates and the frequency of hardware removal between headless and headed screw fixation in TTO. Methods: A retrospective review was conducted on 84 patients (94 knees) who underwent TTO between 2014 and 2024. Patients were divided into two groups based on the type of fixation used: headless screws (56 knees) and headed screws (38 knees). Demographic characteristics, perioperative variables, functional outcomes (Kujala, Lysholm, and Tegner scores), complications, and reoperation rates were compared with a minimum one-year follow-up. Results: No significant differences were found between the groups in terms of baseline demographic and clinical characteristics. Symptomatic implant removal occurred in 13.2% of the headed screw group and in none of the patients in the headless screw group (p = 0.001). Reoperation for any reason was significantly lower in the headless group (3.6% vs. 26.3%, p = 0.002). Functional outcomes were similar between groups. Post-hoc power analysis confirmed sufficient statistical power (98.8%) to detect differences in implant removal rates. Conclusion: Headless screw fixation in TTO was associated with significantly lower rates of hardware-related reoperations and painful implant removal, while achieving functional outcomes similar to those with headed screws. Headless screws may represent a preferable fixation method for reducing implant-related complications in TTO.

Purpose: The purpose of this study was to investigate how the choice of axial CT level affects the reliability and diagnostic accuracy of the Dejour classification for trochlear dysplasia and to evaluate a novel level defined at the most superior extent of the Blumensaat line. Materials and methods: Patients who presented with patellar instability or acute patellar dislocation between 2014 and 2024 and had preoperative CT scans were retrospectively reviewed. Fifty patients were randomly selected based on an a priori sample size calculation. For each knee, four axial CT levels were reconstructed: midpatellar level, Roman arc level, 3 cm above the joint line, and the top of the Blumensaat line. A consensus Dejour grade (A–D) was established by an experienced musculoskeletal radiologist and an orthopedic sports surgeon and used as the reference standard. Two orthopedic surgeons independently graded all 200 axial images twice at least 15 days apart. Quadratic weighted kappa (κ) with 95% confidence intervals (CI) was used to assess intra- and inter-observer reliability and agreement with the consensus. Diagnostic accuracy was defined as the proportion of correctly classified cases relative to the consensus and was compared across levels using Cochran’s Q test. Results: When all four levels were combined, intra-observer reliability was almost perfect for both observers (κ = 0.96 and 0.84; exact agreement 91% and 84%), and inter-observer reliability was substantial to almost perfect (κ = 0.72 and 0.78; exact agreement 72–73%). Agreement with the consensus across all levels was moderate (κ = 0.52–0.58; exact agreement 51–52%). Analyzing levels separately, intra-observer κ remained high at all levels, whereas inter-observer agreement and agreement with the consensus varied markedly. The midpatellar level showed only moderate inter-observer reliability and fair-to-moderate agreement with the consensus (κ = 0.36; accuracy 34–40%), whereas the top of the Blumensaat line showed the highest agreement with the consensus (κ 0.69) and the highest accuracy (up to 64%; pooled 61%); however, statistically significant between-level differences were detected in only one observer–time comparison. The 3 cm above the joint line and the Roman arc level demonstrated intermediate performance. Conclusions: Although intra-observer reliability of the Dejour classification is high regardless of axial CT level, both inter-observer agreement and diagnostic accuracy depend strongly on the selected slice. The axial CT level at the top of the Blumensaat line showed a consistent trend toward higher agreement and accuracy relative to the consensus standard and may be used as a standardized reference slice within routine multi-slice CT assessment to improve reproducibility; however, it should complement comprehensive imaging review and clinical evaluation.

Purpose: This retrospective study aimed to compare the clinical and radiological outcomes of Fulkerson tibial tubercle osteotomy (TTO) fixed with either bioabsorbable magnesium (Mg) or titanium (Ti) headless compression screws, particularly focusing on the need for implant removal. Materials and Methods: 29 patients (19 Ti, 10 Mg screws) who underwent TTO between 2013 and 2023 were included. The primary outcome was implant removal; secondary outcomes included Kujala and Lysholm scores, complication rates, and radiographic union. Rehabilitation protocols were standardized, but early weight-bearing was delayed in the Mg group to mitigate potential implant degradation effects. Results: Both groups demonstrated significant improvements in Kujala and Lysholm Knee scores postoperatively, with no statistically significant differences between the groups. No cases of implant removal, fixation failure, nonunion, or significant range of motion loss were observed. Radiographically, persistent remnants of Mg screws were detected even after more than five years, raising concerns about incomplete bioabsorption. The Ti screws maintained mechanical stability without evidence of loss of fixation or the need for revision. Patient satisfaction and cosmetic outcomes were similar. Conclusion: The use of bioabsorbable Mg screws in TTO did not confer additional clinical or radiological benefits compared to headless Ti screws. Given the higher cost, the incomplete resorption observed at long-term follow-up, and the absence of an implant removal requirement in either group, the routine use of Mg screws cannot be recommended. Ti headless compression screws offer a cost-effective, reliable fixation method, achieving stable osteotomy healing without the need for secondary surgery.