Prospective study on the effects of orthotic treatment for medial knee osteoarthritis in chinese patients: Clinical outcome and gait analysis

Abstract

Objective: To evaluate the effectiveness of various orthotic treatments for patients with isolated medial compartment osteoarthritis. Design: Prospective cohort study with sequential interventions. Setting: University-affiliated hospital, Hong Kong. Patients: From December 2010 to November 2011, 10 patients with medial knee osteoarthritis were referred by orthopaedic surgeons for orthotic treatment. All patients were sequentially treated with flat insole, lateral-wedged insole, lateralwedged insole with subtalar strap, lateral-wedged insole with arch support, valgus knee brace, and valgus knee brace with lateral-wedged insole with arch support for 4 weeks with no treatment break. Three-dimensional gait analysis and questionnaires were completed after each orthotic treatment. Main outcome measures: The Western Ontario and McMaster Universities Arthritis Index (WOMAC), visual analogue scale scores, and peak and mean knee adduction moments. Results: Compared with pretreatment, the lateralwedged insole, lateral-wedged insole with arch support, and valgus knee brace groups demonstrated significant reductions in WOMAC pain score (19.1%, P=0.04; 18.2%, P=0.04; and 20.4%, P=0.02, respectively). The lateral-wedged insole with arch support group showed the greatest reduction in visual analogue scale score compared with pretreatment at 24.1% (P=0.004). Addition of a subtalar strap to lateral-wedged insoles (lateral-wedged insole with subtalar strap) did not produce significant benefit when compared with the lateral-wedged insole alone. The valgus knee brace with lateral-wedged insole with arch support group demonstrated an additive effect with a statistically significant reduction in WOMAC total score (-26.7%, P=0.01). Compliance with treatment for the isolated insole groups were all over 90%, but compliance for the valgus knee brace–associated groups was only around 50%. Gait analysis indicated statistically significant reductions in peak and mean knee adduction moments in all orthotic groups when compared with a flat insole. Conclusions: These results support the use of orthotic treatment for early medial compartment knee osteoarthritis.

目的：評估各種矯形治療對於內側膝單室退化性關節炎患者的效果。 設計：連續性干預的前瞻性隊列研究。 安排：香港一所大學附屬醫院。 患者：從2010年12月到2011年11月，由骨科醫生轉介須進行矯正治療的內側膝退化性關節炎共有10例。所有患者均連續四週逐一接受以下治療：平鞋墊、外側楔型鞋墊、以綁帶將外側楔型鞋墊綁在腳底下、外側楔型鞋墊搭配足弓墊、護膝，以及外側楔型鞋墊搭配足弓墊並加上護膝。每次治療後均進行三維步態分析，並讓患者填寫問卷。 主要結果測量：西安大略和麥克馬斯特大學關節炎指數（WOMAC）、視覺模擬量表評分，以及峰值和平均膝蓋內收力矩。 結果：與治療前相比，外側楔型鞋墊、外側楔型鞋墊搭配足弓墊和護膝治療的WOMAC疼痛子量指數顯著減少（其比率和P值依次為：19.1%，P=0.04；18.2%，P=0.04；20.4%，P=0.02）。與治療前相比，外側楔型鞋墊搭配足弓墊治療的視覺模擬量表得分改善幅度最大（24.1%；P=0.004）。至於以綁帶將外側楔型鞋墊綁在腳底下的治療，與單獨使用外側楔型鞋墊相比，並沒有明顯改善。外側楔型鞋墊搭配足弓墊並加上護膝的治療得到累加效應，其WOMAC總指數顯著下降（-26.7%，P=0.01）。所有使用外側楔型鞋墊的病人依從性均超過九成，可惜搭配護膝治療的依從性只有五成左右。步態分析顯示與平鞋墊比較，所有治療的峰值和平均膝蓋內收力矩均顯著下降。 結論：以上結果支持應在早期使用矯形治療醫治內側膝退化性關節炎。