Research Article: Excessive tibial valgus was not associated with worse 5-year clinical outcomes after medial opening-wedge high tibial osteotomy for advanced knee osteoarthritis: a retrospective cohort study
Abstract:
To evaluate whether excessive tibial valgus, defined as a medial proximal tibial angle (MPTA)?>?95° at the final follow-up, was associated with worse 5-year clinical outcomes after medial opening-wedge high tibial osteotomy (MOWHTO) in patients with Kellgren-Lawrence (K-L) grade IV medial compartment knee osteoarthritis.
This retrospective cohort study included 165 knees with K-L grade IV medial compartment knee osteoarthritis that underwent MOWHTO. Knees were classified according to the MPTA measured on weight-bearing full-length radiographs at the final follow-up as MPTA >95° ( n =?81) or MPTA ?95° ( n =?84). The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at the final follow-up. Secondary outcomes included the Lysholm score, visual analogue scale (VAS) for pain, knee range of motion (ROM), and radiographic parameters. Between-group changes were compared, and clinical outcomes were further evaluated using baseline-adjusted analysis of covariance.
The mean follow-up duration was 64.49?±?3.60 months. WOMAC, Lysholm, VAS, and ROM improved significantly from baseline to the final follow-up in the overall cohort (all P <?0.001). At the final follow-up, WOMAC, Lysholm, VAS, and ROM did not differ significantly between the MPTA >95° and MPTA ?95° groups. Although changes in MPTA and hip–knee–ankle angle were greater in the MPTA >95° group, no significant between-group differences were observed in changes in WOMAC, Lysholm, VAS, or ROM after Holm adjustment. In baseline-adjusted analyses, an MPTA >95° was not significantly associated with WOMAC (adjusted mean difference, ?0.16; 95% CI, ?5.42 to 5.11; P =?0.953), Lysholm (0.24; 95% CI, ?3.22 to 3.69; P =?0.893), VAS (?0.07; 95% CI, ?0.39 to 0.24; P =?0.645), or ROM (?1.52°; 95% CI, ?4.44 to 1.39; P =?0.306).
In patients with K-L grade IV medial compartment knee osteoarthritis treated with MOWHTO, an MPTA >95° at the final follow-up was not significantly associated with worse 5-year clinical outcomes. These findings suggest that the 95° MPTA threshold should not be interpreted in isolation as a determinant of clinical outcome; however, they do not define an optimal correction target or support deliberate overcorrection beyond 95°.
Introduction:
Medial opening-wedge high tibial osteotomy (MOWHTO) is a joint-preserving treatment for symptomatic medial compartment knee osteoarthritis (OA) associated with varus malalignment. By correcting the proximal tibial alignment, MOWHTO redistributes load away from the diseased medial compartment while preserving the native knee joint, making it an important option for selected patients with high functional demands ( 1 ). Although HTO has traditionally been used more often in patients with less advanced OA, its role in…
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