Châtain F, Richard A, Deschamps G, Chambat P, Neyret P
Clinique des Cèdres, Grenoble.
Rev Chir Orthop Reparatrice Appar Mot. 2004 Feb;90(1):49-57. doi: 10.1016/s0035-1040(04)70006-9.
We analyzed technical difficulties encountered when performing revision total knee arthroplasty in patients with unicompartmental femorotibial prostheses.
This multicentric retrospective study included 54 revisions of unicompartmental femorotibial prosthesis with implantation of a total knee prosthesis. The series included 45 medial and nine lateral compartment prostheses. A gliding total knee prosthesis was implanted in 53 cases (98%) (39 standard, 14 revision). Mean time to failure of the unicompartmental prosthesis was four years. IKS scores were established at review. The radiological work-up included AP and lateral views in single leg stance and goniometry for 22 medial compartment revisions. Twenty-seven patients were seen for physical examination and x-rays and eight were lost to follow-up; data were recorded from medical files for 19 patients.
The revision procedure was considered easy in 82% of the cases. Mean follow-up after revision was four years (range 2 - 12 years). Subjective outcome was very satisfactory for 56% of the patients, satisfactory for 36% and unsatisfactory for 8%. The mean function score was 62 points, the mean knee score 85 points, and the mean flexion was 113 degrees. No laxity was found for 90% of the knees. The femorotibial angle was 180 +/- 2 degrees in 46% of the patients. The mechanical femoral angle was 90 degrees in 54% of the patients with 2-4 degrees varus in 42%. The mechanical tibial angle was 90 degrees in 46% of the patients with 2-8 degrees valgus in 37%. Complications included pulmonary embolism (n=2), mobilization under general anesthesia (n=3), arthrolysis (n=1), lateral vertical patellectomy (n=1), and secondary infection (n=1). There were five failures requiring changing the total knee prosthesis.
Loss of bone stock raises specific problems during revision of unicompartmental knee prostheses. Loss of tibial bone is more frequent but it is more difficult to correct for loss of femoral bone. A gliding knee prosthesis is generally preferred for first intention revision. We recommend a long stem when the bone defect is important or involves loss of cortical bone. We have had good mid-term results with revision total knee prostheses after unicompartmental prostheses. Longer follow-up is needed. Poor results were obtained when revision was performed for persistent pain without a clearly defined cause. The presence or not of significant bone loss did not appear to affect outcome. The observation of medial laxity in case of failed lateral unicompartmental prostheses suggests a more constrained total knee prosthesis might be indicated. Compared with earlier series, our results with total knee prostheses after unicompartmental prostheses appear to be better than after tibial valgus osteotomy and also better than after total knee arthroplasty. Conversely, they would be less satisfactory than for primary total knee arthroplasty. The surgical procedure for revision total knee arthroplasty after unicompartmental prosthesis requires precision and skill but is not technically difficult.
我们分析了在单髁股骨胫骨假体患者中进行全膝关节置换翻修术时遇到的技术难题。
这项多中心回顾性研究纳入了54例单髁股骨胫骨假体翻修并植入全膝关节假体的病例。该系列包括45例内侧间室假体和9例外侧间室假体。53例（98%）植入了滑动型全膝关节假体（39例标准型，14例翻修型）。单髁假体的平均失效时间为4年。复查时确立了国际膝关节协会（IKS）评分。影像学检查包括单腿站立位的前后位和侧位片以及对22例内侧间室翻修病例进行角度测量。27例患者接受了体格检查和X线检查，8例失访；从19例患者的病历中记录了数据。
82%的病例中翻修手术被认为操作容易。翻修后的平均随访时间为4年（范围2 - 12年）。56%的患者主观结果非常满意，36%满意，8%不满意。平均功能评分为62分，平均膝关节评分为85分，平均屈曲度为113度。90%的膝关节未发现松弛。46%的患者股胫角为180±2度。54%的患者机械股骨角为90度，42%有2 - 4度内翻。46%的患者机械胫骨角为90度，37%有2 - 8度外翻。并发症包括肺栓塞（n = 2）、全身麻醉下活动（n = 3）、关节松解（n = 1）、外侧垂直髌骨切除术（n = 1）和继发感染（n = 1）。有5例失败需要更换全膝关节假体。
在单髁膝关节假体翻修过程中，骨量丢失会引发特定问题。胫骨骨量丢失更常见，但纠正股骨骨量丢失更困难。初次翻修通常更倾向使用滑动型膝关节假体。当骨缺损严重或涉及皮质骨丢失时，我们建议使用长柄假体。我们对单髁假体后全膝关节置换翻修术取得了良好的中期结果。需要更长时间的随访。对无明确原因的持续性疼痛进行翻修时效果不佳。是否存在明显骨量丢失似乎不影响结果。外侧单髁假体失败时出现内侧松弛提示可能需要更限制性的全膝关节假体。与早期系列相比，我们单髁假体后全膝关节假体的结果似乎比胫骨外翻截骨术后更好，也比全膝关节置换术后更好。相反，它们不如初次全膝关节置换术令人满意。单髁假体后全膝关节置换翻修术的手术操作需要精确性和技巧，但技术上并不困难。
