Small diameter metal-on-metal total hip arthroplasty at 13 years - a follow-up study.

INTRODUCTION: Theoretically, the properties of second-generation metal-on-metal (MoM) bearings are better for wear, osteolysis and longevity. However, follow-up studies of more than 10 years are rare, in particular with hybrid fixation (cemented stainless steel stems and cementless cup), therefore we evaluated the results of this combination after a mean follow-up of 12.8 years: (1) to analyze the survival rate, (2) to compare it with the survival rate in the same series after 6.4 years (95.8% cup, 94.8% stem), (3) to evaluate clinical and radiographic outcome and (4) to analyze these failures. HYPOTHESIS: The number of revisions would increase after 10 years. MATERIALS AND METHODS: We evaluated 106 total hip arthroplasties (THA) (Cedior™ press-fit cup with cemented Acora™ (n=50) and Exafit™ (n=56) stems and 28mm Metasul™ bearings performed between January 1999 and December 2002. The survival rate was calculated by the Kaplan-Meier method. The clinical assessment included the Postel Merle d'Aubigné (PMA) and Oxford scores. The radiographic assessment evaluated radiolucencies and osteolysis on standard X-rays. A histological analysis was only performed during revision THA. RESULTS: After a mean 12.8 years of follow-up (10-16), 53 THA were reviewed in 48 patients. Thirteen THA revisions (14%) were performed including 11 aseptic revisions (5 stem fractures, 2 cases of impingement and 3 loosenings [1 bipolar and 3 cups] and one case of osteolysis). Overall survival, taking into account revision for aseptic loosening, was 87.6% (CI 95%=77.3 to 99.3%). The mean PMA and Oxford scores at the final follow-up were 17.6±0.8 points (16-18) and 16.5±5.2 points (12-38) respectively. The radiological follow-up mainly identified radiolucencies around the stem in Gruen zones 1 and 7 (17 and 21% respectively). DISCUSSION: The survival rate of hybrid MoM THA in this series decreased after 10 years and is lower than studies evaluating cementless THA with the 28-mm Metasul™ bearings (90.9 to 100% survival). Although the clinical results are satisfactory, survival is lower. However, the role of MoM bearings is relative in these failures, in particular because trunnionoses (stainless steel stem with 28-mm head), impingement and especially 5-stem fractures were the main causes of failure. LEVEL OF EVIDENCE: IV: retrospective study.

Does preoperative subscapularis fatty muscle infiltration really matter in anterosuperior rotator cuff tears repair outcomes? A prospective multicentric study.

INTRODUCTION: Anterosuperior (AS) rotator cuff tear describes a combined tear of the subscapularis and the supraspinatus tendons. We hypothesized that results after AS tendon repairs might be influenced by the size of the subscapularis rupture and the preoperative subscapularis muscle fatty infiltration. METHODS: A prospective multicentric study of 53 AS rotator cuff tears from five centers was performed (January 2008-January 2009). Subscapularis tendon retraction and fatty infiltration were assessed preoperatively. An ultrasonographic healing control was performed 1 year after surgery. RESULTS: Patients were on average 60 years (range, 43-75 years) and were operated on average 16 months (range, 2-72 months) after the beginning of their symptoms. The incidence of AS tears was found to be 18%. Average follow-up was 15 months (range, 12-24). The Constant-Murley (CM) score for the patients with AS ruptures improved significantly from 49 points (range, 35-51 points) preoperatively to 73 points postoperatively (range, 50-95 points)(P=0.0205). CM score gains were 26 for Lafosse group 1 ruptures and 29 for Lafosse group 2 & 3 with pre- and postoperative P values at P<0.0000001 and P<0.000001, respectively. The last follow-up CM score according to the subscapularis fatty infiltration was 70 (range, 48-95) for groups 0-1, 70 (range, 56-87) for group 2, and 56 (range, 53-88) for groups 3-4 with pre- and postoperative P values at P<0.001, P<0.001, and P<0.004, respectively. The global retear rate was 6%. DISCUSSION: Our study showed that the CM score after repairs of AS rotator cuff tears was lower in advanced subscapularis fatty infiltration. However, gains in CM scores were similar whatever the initial subscapularis fatty infiltration. The rate of tendon healing was correlated with subscapularis fatty infiltration. Subscapularis tendon rupture size was not significantly correlated with outcomes. LEVEL OF EVIDENCE: Level III.

Patellar height modification after high tibial osteotomy by either medial opening-wedge or lateral closing-wedge osteotomies.

PURPOSE: High valgus tibial osteotomy is used to treat medial femoro-tibial osteoarthritis. Changes in patellar height due to high valgus tibial osteotomy can cause technical difficulties during subsequent knee arthroplasty. The primary objective of this study was to assess the hypothesis that patellar height decreases after opening-wedge osteotomy and increases after closing-wedge osteotomy. The secondary objective was to assess whether frontal axis correction and tibial slope modification correlated with patellar height changes. METHODS: A multicentre, prospective, comparative, observational, non-randomised study was conducted in consecutive patients undergoing isolated high valgus tibial osteotomy according to standard practice in each of the ten study centres. Patellar height was assessed based on the Caton-Deschamps index. RESULTS: Of 321 included patients, 224 underwent opening-wedge and 97 closing-wedge osteotomy. Patellar height did not change significantly after closing-wedge osteotomy (1.07 ± 0.2 pre-operatively and 1.0 ± 0.19 postoperatively). Patellar height decreased significantly after opening-wedge osteotomy (from 0.98 ± 0.19 to 0.88 ± 0.21, p < 0.0001, mean decrease 9 ± 22%). Patellar height decreased by more than 20% in 49 (28%) patients after opening-wedge osteotomy. The patellar height decrease after opening-wedge osteotomy correlated significantly with axis correction magnitude and tibial slope change. CONCLUSION: Our results support routine baseline measurement of patellar height before high valgus tibial osteotomy and posterior positioning of the opening wedge to limit the tibial slope change in patients requiring major axis correction by opening-wedge osteotomy. LEVEL OF EVIDENCE: Prospective cohort study, Level II.