Small but Significant Effect on Patellar Height and Tibial Tuberosity‐Trochlear Groove Distance Following Ascending Versus Descending Tibial Tubercle Osteotomy in Medial Open‐Wedge High Tibial Osteotomy

Purpose To compare radiographic patellofemoral characteristics following ascending tibial tubercle (AT) and descending tibial tubercle (DT) medial open‐wedge high tibial osteotomy (OWHTO). Methods This retrospective single‐center study included all patients who underwent AT‐OWHTO or DT‐OWHTO between October 2014 and December 2022 with complete radiographic datasets and ≥12 months of follow‐up. Patellar height (Caton‐Deschamps index) and tibial tuberosity‐trochlear groove distance (TT‐TG) were measured on standardized radiographs and computed tomography scans preoperatively and at 4.5 and 12 months postoperatively. Coronal alignment (hip‐knee‐ankle angle), sagittal alignment (posterior tibial slope), and hinge‐fracture occurrence were analyzed. Results A total of 106 knees from 103 patients (83 men, 20 women; mean age 43.5 ± 8.9 years) were analyzed (48 AT, 58 DT). AT‐OWHTO decreased the Caton‐Deschamps index from 0.79 ± 0.14 to 0.69 ± 0.13 ( P < .001) and increased TT‐TG from 12.71 ± 3.41 to 14.93 ± 4.01 mm ( P < .001). DT‐OWHTO maintained the Caton‐Deschamps index (0.76 ± 0.13 to 0.75 ± 0.14; P = .054) and TT‐TG (13.86 ± 4.65 to 13.37 ± 4.93 mm; P = .057). A total of 46 hinge fractures (43.4%) were detected, 19 in the AT‐OWHTO and 27 in the DT‐OWHTO group ( P = .471). Conclusions A significant decrease in patella height and a significant increase in TT‐TG were observed in AT‐OWHTO, whereas these parameters remained stable in DT‐OWHTO. Although the absolute magnitude of these radiographic changes was small, preoperative assessment of patellar height and TT‐TG may assist in selecting the appropriate osteotomy technique to preserve patellofemoral joint alignment. Level of Evidence Level III, retrospective cohort study.