J Orthop Traumatol. 2014 Mar;15(1):47-54. doi: 10.1007/s10195-013-0268-5.
Though a number of series with long-term results have been published, there is still a paucity of literature on the role of patellar height after unicompartment knee arthroplasty (UKA). The present study was conducted with a hypothesis that patella baja may lead to a poor outcome at follow-up.
A retrospective review of 134 knees was performed and patellar height calculated before and after UKA by Blackburne-Peel index (BPI) and the Insall-Salvati ratio (ISR) on true lateral radiographs of the patients in 30° of flexion taken pre-operatively and at 1 year, 2 years and final follow-up (minimum 5 years). Statistical analysis was performed to evaluate the outcomes.
There was a decrease in ISR in 14.18 % and in BPI in 19.4 % at final follow-up. There was a significant decrease in BPI values while the decrease was not significant for ISR. After eliminating the pre-operative patella baja, 7.3 % developed post-operative patella baja, according to ISR, while 11.5 % developed patella baja as per BPI. At final follow-up there was a statistically significant decrease in stair climbing scores in patients with patella baja when compared to patients with normal ISR.
Patients with a decrease in patellar height as per ISR have a decrease in stair climbing score at mid-term follow-up while the overall KSS, and pain scores are not affected by a change in patellar height and neither is there a significant progress in patellofemoral osteoarthritis among patients with patella baja compared to normal patella.
尽管已经发表了许多具有长期结果的系列研究，但关于单髁膝关节置换术后（UKA）髌骨高度的作用仍缺乏文献记载。本研究的假设是髌骨低位可能会导致随访结果不佳。
回顾性分析了 134 例膝关节，通过 Blackburne-Peel 指数（BPI）和 Insall-Salvati 比值（ISR）在术前、术后 1 年、2 年和最终随访（至少 5 年）时的 30°膝关节屈曲位的患者真实侧位 X 线片上计算 UKA 前后的髌骨高度。进行了统计学分析以评估结果。
最终随访时 ISR 下降 14.18%，BPI 下降 19.4%。BPI 值明显下降，而 ISR 下降不明显。在消除术前髌骨低位后，根据 ISR，有 7.3%的患者术后出现髌骨低位，而根据 BPI，有 11.5%的患者出现髌骨低位。在最终随访时，与 ISR 正常的患者相比，髌骨低位患者的上下楼梯评分明显降低。
根据 ISR 降低髌骨高度的患者在中期随访时上下楼梯评分降低，而总体 KSS 和疼痛评分不受髌骨高度变化的影响，并且与正常髌骨的患者相比，髌股关节炎也没有明显进展。
