ABSTRACT
BACKGROUND: Acetabular screw cups seem to give high primary stability. We analyzed the migration and loosening behavior of a first-generation screw cup in a longterm follow-up. PATIENTS AND METHODS: We examined 92 uncemented titanium alloy conical screw cups prospectively. Implant migration was assessed with a digital high-precision method (EBRA) with an accuracy of 1.0 mm. RESULTS: After mean 11 (0.5-18) years, 87 patients were available for examination and 5 patients had died. 32 implants had been revised and 7 cases showed radiographic evidence of loosening. The 10-year survival rate was 71%. Migration of more than 1 mm occurred in 53 hips. Implant survival was strongly associated with an annual migration of greater than 0.2 mm. INTERPRETATION: The long-term behavior of this cup is not satisfactory. In spite of extraordinarily high primary implant stability, secondary osseointegration of this cup often fails. The annual migration rate represents a valid parameter for prediction of implant survival.
Subject(s)
Arthroplasty, Replacement, Hip/adverse effects , Bone Screws , Hip Prosthesis/adverse effects , Acetabulum/surgery , Adult , Arthroplasty, Replacement, Hip/instrumentation , Bone Screws/adverse effects , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Prosthesis Design , Prosthesis Failure , TitaniumABSTRACT
PURPOSE: The goal of this study was to evaluate the intra-articular pathology in patients with atraumatic shoulder instability who did not respond to conservative treatment. TYPE OF STUDY: Prospective case series. METHODS: Of 226 patients treated for shoulder instability over a 2-year-period, 43 patients (average age, 27.5 years; 26 men and 17 women) were classified as having atraumatic instability. None had responded to physiotherapy. The intra-articular pathology was documented during diagnostic arthroscopy before the definitive surgical procedure. RESULTS: Three types of lesions of the capsulolabral complex were defined: incomplete labral lesions, pathologic elongation of the capsule or "non-Bankart lesions" (type I), classic Bankart lesions (type II), and complex lesions of the labrum and capsule (type III). Type I was found in 19 patients (44.2%); type II lesions were seen in 13 (30.2%); and type III in 11 (25.6%) patients. Hill-Sachs lesions were found in 26 shoulders (60.5%). Chondral lesions of the glenoid were seen in 10 shoulders (23%); SLAP lesions in 5 (11.7%); and partial, articular-side defects of the supraspinatus tendon in 3 (6.9%) patients. CONCLUSIONS: Atraumatic onset of shoulder instability does not imply the absence of intra-articular lesions, at least in patients not showing a response to physiotherapy. Arthroscopy is helpful to diagnose the definite intra-articular pathology. LEVEL OF EVIDENCE: Level IV.
