Both from experimental studies and the large arthroplasty registries there is evidence that bacteria are more often involved in implant loosening then is currently reported. To further elucidate this potential problem, the current study investigated the hypothesis that many total hip arthroplasty revisions, classified as aseptic, are in fact low-grade infections missed with routine diagnostics. In 7 Dutch hospitals, 176 patients with the preoperative diagnosis of aseptic loosening of their total hip arthroplasty were enrolled. From each patient, the preoperative history was obtained. During surgery, between 14 and 20 tissue samples were obtained for routine culture, pathology analysis and broad range 16S rRNA PCR with reverse line blot hybridization (PCR-RLB). Samples were taken from the (neo-) capsule and acetabular and femoral interface tissue. Cultures were performed locally according to similar protocols. One specialized pathologist, blinded for all other results, analyzed all pathology samples. The PCR-RLB analysis was performed centrally, using a technique previously validated for orthopedic use. Patients were classified as not infected, suspect for infection or infected, according to strict, predefined criteria. Each patient had a follow-up visit after 1 year.Background
Methods
The complications of prostheses for fractures of the proximal humerus are understudied because the experience of each shoulder surgeon is limited and a standardised registration protocol is not yet available. A prospective study on complications in shoulder arthroplasty for fracture is, therefore, essential to explore variables that influence outcome. The purpose of this study is to report our experience with complications following arthroplasty for proximal humeral fractures. In a multicenter study, four hundred and six patients treated with arthroplasty for proximal humeral fracture were prospectively followed during a nine year period; three hundred patients with a minimum of two years follow-up, at an average of forty-five months (range, 24–117), were available for review. Objective results were graded with the Constant score and range of motion. Subjective results were reported according to patient satisfaction. At follow-up, the average Constant score was fifty-four points (range, 14–95) and active forward elevation was 103° (range, 10°–180°). Eighty-one percent of patients were satisfied or very satisfied. We observed a 59% rate of late (after three months) complications, including a high rate of tuberosity-related complications (72% malunion or nonunion). Initial tuberosity malposition was present in 35% of the patients. Secondary migration despite initial good positioning was observed in 24%. Tuberosity complications were associated with poor final Constant score, poor range of motion and shoulder pain (p=0.001 for all items). A re-operation was performed in 5.3% of the cases. Patients who were mobilised according to the ‘early passive motion’ concept had double the incidence of secondary tuberosity migration, compared to those that were initially immobilised (14% versus 27%, p=0.004). Tuberosity complications are the most frequent late complication and they are associated with poor functional results. It is, therefore, incumbent upon the surgeon to maximise healing with adequate fixation of the tuberosities, followed by sufficient immobilization.
