Sagittal alignment changes predict patellar osteosclerosis after total knee arthroplasty without resurfacing.
retrospective_cohort · Level III
Where this comes from
- Record sourced from PubMed, PMID 42255408.
- Also identified by DOI 10.1002/jeo2.70750 and PMC identifier 13240532.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Total knee arthroplasty (TKA) is an effective treatment for knee osteoarthritis; however, some patients experience post-operative anterior knee pain related to patellofemoral (PF) loading. Subchondral patellar osteosclerosis on radiographs may indirectly reflect increased PF stress. This study examined whether changes in posterior tibial slope (PTS) and femorotibial posterior overhang (FTPO) are associated with patellar osteosclerosis after TKA without patellar resurfacing. A total of 94 knees (71 patients) that underwent TKA without patellar resurfacing for medial OA using the Journey II Bi-Cruciate Stabilized (BCS) system were retrospectively reviewed. Knees were classified according to the presence of post-operative patellar osteosclerosis. Group differences were evaluated using the Mann-Whitney <i>U</i> test, and correlations between ΔPTS and ΔFTPO were assessed with Spearman's coefficient. Receiver operating characteristic (ROC) analysis and multivariable logistic regression were performed to determine cut-off values and independent predictors. Patellar osteosclerosis developed in 26 out of 94 knees (27.7%). The osteosclerosis group showed significantly greater post-operative reductions in both PTS and FTPO (<i>p</i> < 0.001). ΔPTS and ΔFTPO were positively correlated (<i>r</i> = 0.35, <i>p</i> = 0.0006). ROC analysis identified cut-offs of ΔPTS ≤ -0.28° (AUC = 0.91) and ΔFTPO ≤ 0.68 mm (AUC = 0.84). Multivariable analysis confirmed that more negative ΔPTS (odds ratio [OR] = 0.49, 95% confidence interval [CI] = 0.34-0.71) and smaller ΔFTPO (OR = 0.78, 95% CI = 0.65-0.93) independently predicted patellar osteosclerosis. Post-operative reductions in PTS and relative femoral anteriorization were associated with patellar osteosclerosis after TKA without patellar resurfacing. These sagittal alignment changes may contribute to increased PF joint stress and anterior knee pain. Although PF pressure and symptoms were not directly evaluated, avoiding excessive PTS reduction and femoral anteriorization may help minimize PF overloading. Level III.