Same-stage total knee arthroplasty and osteotomy for osteoarthritis with extra-articular deformity. Part II: Femoral osteotomy, prospective study of 6 cases.

BACKGROUND: Same-stage (1S) total knee arthroplasty (TKA) and femoral osteotomy (FO) may deserve consideration in patients with both knee osteoarthritis and severe extra-articular knee deformity (EKD). The objective of this study was to assess clinical and radiological outcomes and morbidity (complications and revisions) in 6 patients managed with S1-TKA-FO. HYPOTHESIS: 1S-TKA-FO produces satisfactory outcomes and is not associated with higher morbidity rates compared to two-stage TKA-TO or TKA with intra-articular EKD correction, while also significantly shortening total treatment duration. MATERIAL AND METHODS: A prospective study was performed in 6 patients managed with 1S-TKA-FO between 1999 and 2011; mean age was 64 years (range, 59-72 years) and mean body mass index was 29.5 (range, 26-35). The EKD was consistently greater than 10°. The cause was post-traumatic mal-union in 4 patients, constitutional EKD in 1 patient, and FO in 1 patient. In each patient, the clinical International Knee Society (IKS) score and the hip-knee-ankle angle (HKA), femoral mechanical angle (FMA) and tibial mechanical angle (TMA), were recorded prospectively before and after surgery. RESULTS: A long uncemented extension stem was used in all 6 patients and a posterior-stabilised implant in 5 patients. No hinged implants were used. In 4 patients, internal fixation of the FO was performed. Mean follow-up was 10 years (range, 4-15 years). From baseline to last follow-up, the mean IKS score increased from 46 to 161 and mean flexion from 95° (range, 70-110°) to 107° (range, 90-120°). The HKA measured radiographically was between 178° and 182° in all 6 patients. The complications consisted of deep vein thrombosis in 1 patient and knee stiffness requiring manipulation under general anaesthesia in 1 patient. No patient experienced mal-union or required revision surgery. DISCUSSION: Apart from a case-series study of 11 patients, very few data are available on 1S-TKA-FO. In our small population, no major complications were recorded. The encouraging long-term outcomes warrant a recommendation to perform 1S-TKA-FO in patients with knee osteoarthritis and an intra-femoral deformity greater than 10°. LEVEL OF EVIDENCE: IV, prospective observational cohort study.

Total knee replacement on more than 20° valgus: A case control study.

INTRODUCTION: Lower-limb valgus deformity exceeding 20° is a particular case, with few publications assessing the impact of the severity of the valgus. The present retrospective case control study compared a series of>20° valgus versus a series of 10-20° valgus, assessing (1) operative data [approach, type of total knee replacement (TKR)], (2) complications and implant survival, and (3) clinical and radiological results. HYPOTHESIS: Severe valgus deformity requires TKR with greater constraint, incurring a higher rate of complications and poorer implant survival. MATERIAL AND METHOD: A multicenter retrospective study for the period January 2006 to December 2010 included 53 patients, with a mean age of 72±10 years, presenting>20° valgus. The study series was matched for age and gender with a series of 53 cases of 10-20° valgus. Convexity laxity was greater in the>20° group (p=0.004). RESULTS: There was no significant inter-group difference in approach (p=0.13). Greater constraint was more frequent in the>20° group (7/53 versus 1/53; p=0.03), independently of convexity laxity or Krackow grade (p=0.14). There were 7 complications (13.2%) in the>20° group and 7 in the 10-20° group (NS). Eight-year survivorship was 95.12% in the>20° group and 94.9% in the 10-20° group (p=0.63). There were no significant differences in Oxford score (p=0.30) or HKA angle (p=0.78) at last follow-up. CONCLUSION: The study hypothesis was partially confirmed: greater constraint was more frequent in>20° valgus. The number of complications was low, and survival was identical to that of a control group with less severe deformity. LEVEL OF EVIDENCE: III, retrospectivecase controlstudy.