No benefits of knee osteotomy patient's specific instrumentation in experienced surgeon hands.

PURPOSE: To compare the clinical and radiological outcomes of patient-specific instrumentation (PSI) with the conventional free hand (FH) technique in performing coronal plane corrective knee osteotomies in terms of limb alignment and functional scores. The hypothesis is that conventional FH technique in experienced hands with proper pre-operative planning is as precise as PSI. METHODS: Patients who underwent coronal plane corrective knee osteotomies with either PSI or FH technique between 2017 and 2019 by the same senior surgeon and have a minimum of 2 years follow-up period were included in this study. A total of 91 knees (84 patients) with mean age of 42.9 ± 12.5 years who had a pre- and post-operative complete weight-bearing radiographic work-up (50 of them were performed with the FH technique and 41 by means of PSI) were included for comparison. The data were retrospectively reviewed both radiologically and clinically using the Knee Injury and Osteoarthritis Outcome Score (KOOS) sub-scores. All cases in both groups were evaluated for the following measurements: hip-knee-ankle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), and joint line convergence angle (JLCA) both preoperatively and postoperatively. In addition, FH and PSI osteotomy cases were also compared for their precision in achieving the target correction that was planned preoperatively. All cases were also evaluated clinically preoperatively and at 2-year follow-up using KOOS sub-scores and the two groups were compared. RESULTS: The mean HKA precision was 1.5 ± 0.9 in FH group and 1.3 ± 0.7 in PSI (P value = n.s.), the mean MPTA precision was 1.6 ± 1.6 in FH group and 2.1 ± 1.2 in PSI (P value = n.s.), the mean m-LDFA precision was 1.9 ± 1.7 in FH group and 1.4 ± 1.3 in PSI (P value = n.s.), and the mean JLCA precision in the FH group was 1.5 ± 1.2 and 1.7 ± 1.2 in PSI (P value = n.s.). For all the radiographic parameters, there were no statistically significant differences between the target correction and the obtained correction in both groups. Moreover, PSI and FH techniques were comparable in terms of clinical outcomes and no significant difference was found between the two groups in any of the 2-year follow-up KOOS sub-scores. CONCLUSION: Conventional FH method in the hands of experienced surgeons is as precise as PSI in reliably achieving the planned correction in different coronal plane knee corrective osteotomies. Moreover, there was also no difference between both methods in the 2-year clinical outcome scores.

In slope-changing osteotomy one millimeter is not one degree: results of an artificial intelligence-automated software analysis.

BACKGROUND: Anterior closing wedge osteotomies (ACWO) are performed in revision anterior cruciate ligament (ACL) surgery to correct an excessive posterior tibial slope (PTS). PURPOSE: With the help of automated planning software, this study investigates the assumption that 1mm of wedge height gives 1° of slope correction (1:1). METHODS: Fifty patients underwent ACWO, with the wedge height calculated using the 1:1 formula. Pre- and postosteotomy PTS were measured manually, and the achieved post-operative PTS was compared with the target PTS of 5.3° ± 1.9. The X-ray analysis was repeated virtually with the automated software, which also recommended a resection height. These parameters were then compared with the manually obtained parameters. RESULTS: Using a 1:1 formula, wedge heights of 8.5mm ± 2.3 was resected to achieve a PTS of 4.2° ± 0.32. This showed an overcorrection of 1.6° ± 0.8 from the target slope. This was consistent with the data from the automated software, which recommended a lower wedge height of 7.7mm ± 2.9. CONCLUSION: In trans-tubercle ACW, using a wedge height (mm) to slope correction (°) ratio of 1:1 can lead to slight over-correction. Automated software planning is useful for planning correction osteotomies in the sagittal plane.