Ye Geon Noh

Background and Objectives: Postoperative alignment after medial open-wedge high tibial osteotomy (MOWHTO) reflects both osseous correction and load-dependent joint response. We evaluated the internal radiographic performance of a prespecified threshold-based latent medial laxity (LML) adjustment and explored alternative deduction models. Materials and Methods: Seventy-two consecutive eligible knees were retrospectively analyzed. LML, defined operationally as the difference between joint-line convergence angles on supine valgus-stress and standing radiographs, was treated as a composite load-and-stress response. One-third of LML was deducted from the target correction angle when LML was ≤5°, and one-half when LML was >5°. The primary outcome was 1-year hip–knee–ankle (HKA) error within ±1.0°. Change in mechanical medial proximal tibial angle (ΔmMPTA) served as a radiographic proxy for executed osseous correction. Alternative deduction rules were compared by internal counterfactual analysis with leave-one-out cross-validation for fitted models. Results: Fifty-two knees (72.2%; 95% CI, 60.4–82.1%) were within ±1.0° of target. Mean signed error was −0.38 ± 0.95° (p = 0.001), with Bland–Altman limits of agreement from −2.25° to 1.49°. Mean ΔmMPTA was 6.03 ± 2.59°, versus a planned osseous correction of 6.81 ± 1.41°; the execution proxy averaged −0.78 ± 2.13° (p = 0.003). The residual planning component averaged +0.40 ± 2.04° (p = 0.098). In the internal comparison, the threshold rule yielded an MAE of 0.76° and 72.2% within ±1.0°, versus 1.79° and 41.7% with no adjustment. An exploratory continuous model (deduction = −1.77 + 0.736 × LML) yielded an MAE of 0.66° and 79.2% within ±1.0° (leave-one-out MAE, 0.68°). Conclusions: Threshold-based LML adjustment reproduced the individualized 1-year HKA target within ±1.0° in 72.2% of knees. This simple method appears feasible for preoperative planning; however, the small target-relative undercorrection bias warrants further refinement and prospective comparative validation.

Background and Objectives: Since the neck is the weakest part of the metacarpals, the most common metacarpal fracture is a neck fracture, a type which accounts for 38% of all hand fractures. Such fractures can be fixed using a variety of conventional techniques, including intramedullary pinning and K-wire pinning. However, conventional techniques involve complications, such as angulation, stiffness, and rotational deformity. The purpose of this study was to compare the usefulness of our new technique, combined intramedullary pinning with K-wire pinning (IPKP), with those of intramedullary pinning (IP) and K-wire pinning (KP). Materials and Methods: This was a single-center, randomized controlled trial conducted between January 2005 and April 2023. A total of 158 patients with acute displaced fractures of the fifth-metacarpal neck were randomly assigned to either the IPKP group (n = 48), the KP group (n = 60), or the IP group (n = 50). We radiographically evaluated angulation and shortening in three visits: pre-operatively, post-operatively, and at a 1-year follow-up. We clinically evaluated the ranges of motion and Quick-DASH scores to assess daily living performance and the cosmetic scores, using the SBSES score, to assess patients’ satisfaction with their cosmetic outcomes. Results: The IPKP group was superior to the KP group and the IP group regarding radiographical and clinical assessments at the 1-year follow-up visit. The angulation was 15.7° (±7.7) in the KP group, 17.0° (±5.9) in the IP group, and 12.6° (±2.5) in the IPKP group (p < 0.001) at the 1-year follow-up visit. The shortening was 0.9 mm (±0.3) in the KP group, 1.4 mm (±0.2) in the IP group, and 0.4 mm (±0.1) in the IPKP group (m < 0.001) at the 1-year follow-up visit. The TAM was 272.6° (±17.5) in the KP group, 271.1° (±18.0) in the IP group, and 274.1° (±14.9) in the IPKP group (p = 0.42). Four patients (6.6%) in the KP group and two patients (4%) in the IP group were reported as having stiffness, while no patients were found to have stiffness in the IPKP group. The average Quick-DASH score was 2.3 (±0.5) in the KP group, 2.5 (±0.4) in the IP group, and 1.9 (±0.4) in the IPKP group (p > 0.05). The average cosmetic score was 3.7 (±1.2) in the KP group, 3.8 (±0.9) in the IP group, and 4.7 (±0.8) in the IPKP group (p < 0.001). A complication involving nonunion occurred in one case (1.6%) in the KP group, while there were three cases (6%) of rotational deformity in the IP groups. Conclusions: With the IPKP technique, accurate reduction can be achieved to improve hand function and cosmetic outcomes.