Development of a machine learning model for identifying the optimal situation favoring double-level osteotomy over single-level high tibial osteotomy.

BACKGROUND: This study aimed to develop a machine learning (ML) model to identify the optimal situation wherein double-level osteotomy (DLO) is favored for severe varus knees by analyzing unfavorable outcomes. This study hypothesized that there are the most favorable algorithms and contributing factors for identifying the optimal situation favoring DLO over opening-wedge high tibial osteotomy (OWHTO). METHODS: Data were retrospectively collected from patients who underwent OWHTO (505 knees). Unfavorable outcome parameters were defined as follows: (1) medial proximal tibial angle (MPTA) > 95°, (2) joint line convergence angle (JLCA) > 4° (insufficient medial release), (3) JLCA < 0° (medial instability), (4) recurrence of varus deformity, and (5) lateral hinge fracture. The input data for the ML model included demographic data and preoperative radiological and intra-operative factors. The ML model was used to evaluate overall and to evaluate each unfavorable outcome. Interpretation by the model was performed by SHapley Additive exPlanations. RESULTS: The unfavorable group had a larger JLCA and MPTA preoperatively than the favorable group in the conventional comparison. The light gradient boosting machine (LGBM) demonstrated the highest AUC of 0.66 and F-1 score of 0.72 among the ML algorithms. In the overall assessment, the preoperative weight-bearing line ratio (WBLR) was the factor that contributed the most, followed by the preoperative JLCA and the ΔWBLR. ΔWBLR and the preoperative JLCA were the contributing factors for each outcome. CONCLUSIONS: The LGBM model was superior in predicting the optimal situations favoring DLO over OWHTO. Preoperative WBLR, preoperative JLCA, and ΔWBLR significantly contributed to the unfavorable outcomes overall and for each outcome in the ML model.

Postoperative Intravenous Iron Supplementation Increases Hemoglobin Level in Total Knee Arthroplasty.

Iron supplementation provides iron storage and facilitates effective production of hemoglobin. The purpose of this study was to investigate the effect of early postoperative intravenous (IV) iron supplementation in different types of total knee arthroplasty (TKA) surgery. We retrospectively analyzed 863 patients who underwent TKA between September 2017 and September 2021. The IV iron (I) and non-IV iron (NI) groups were compared. Hemoglobin responders, defined as patients who showed a change in hemoglobin level of ≥2 g/dL at 6 weeks of surgery compared to the baseline immediate postoperative hemoglobin level, were identified and they were compared with the nonresponders. After logistic regression analysis, the patients were classified according to the type of surgery (unilateral TKA, staged bilateral TKA, and simultaneous bilateral TKA). A subgroup analysis was performed according to the comorbidity as Charlson Comorbidity Index (CCI). The type of surgery and the rate of hemoglobin responders differed between the I and NI groups. The surgery type and iron supplementation significantly affected the hemoglobin responder in the logistic regression model. In each surgery type, hemoglobin drop in the I group was generally lower in the second and sixth weeks than that in the NI group. It was also effective in reducing hemoglobin drop on the first day of the second surgery in staged bilateral TKA. In addition, the number of hospital days was lower in the IV iron supplementation group who underwent a staged bilateral TKA. CCI did not affect hemoglobin responder, hemoglobin drop, and transfusion rate in both the I and NI groups. Postoperative IV iron supplementation affected the outcome of hemoglobin responders. In addition, it reduced early postoperative hemoglobin drop. However, iron supplementation did not affect the transfusion rate, complications, and clinical outcome, regardless of the type of surgery. LEVEL OF EVIDENCE: Level III, case-control study.