Materials and methods: From 1993 to 2001 in 20 patients with rheumatoid arthritis 24 total shoulder arthroplasties were performed. Concerning 19 Biomet total shoulder arthroplasties of which one glenoid component and one humeral component were cemented for optimal fixation. Five Aequalis total shoulder arthroplasties were performed, one with an uncemented glenoid component. The pre-operative diagnosis was rheumatoid arthritis in the whole Biomet-group. In the Aequalis-group there were four patients with rheumatoid arthritis and one patient with juvenile chronic arthritis. The mean age was 48 (19–76) years. The mean pre-operative range of motion was flexion 80 (40–150), external rotation 23 (–20 – 65) and abduction 55 (0–110) degrees. Pre-operative shoulder X-rays were staged according to Larssen. In the Biomet-group this resulted in eight times Larssen 3, nine times Larssen 4 and two times Larssen 5; in the Aequalis-group five times Larssen 4.

All 24 operations were performed by a deltopectoral approach with 11 longitudinal osteotomies of the clavicula, 12 osteotomies of the lesser tubercle, two osteotomies of the greater tubercle and two osteotomies of the coracoid process; all without complications. Seven times a cancellous bone graft of the glenoid was performed. A rotatorcuff rupture was seen five times; in all cases this was closed primarily. A rotatorcuff release was performed four times. Two procedures were complicated: one longitudinal fissure of the humerus and one fractured greater tubercle, both in the Biomet-group. The after-treatment for all shoulder arthroplasties was functional with use of a collar ‘n cuff accompanied by intensive physiotherapy with increasing load of use.

Results: No (sub)dislocation was seen or revision surgery was performed within six weeks after operation. Eight cranial subdislocations and one caudal subdislocation occured and one lesion of the brachial plexus was diagnosed six weeks or more after operation in the Biomet-group. There were no complications in the Aequalis-group. The mean follow-up is 49 (4–93) months. The mean postoperative range of motion was flexion 79 (20–150), external rotation 36 (0–75) and abduction 62 (0–150) degrees. The mean visual analogue painscore (VAS) increased from 3, 3 pre-operatively to 7, 3 postoperatively. Radiolucent lines were seen nine times, cemented Biomet humeral component 1x, uncemented Biomet glenoid component 7x and around cemented Aequalis glenoid component 1x. Two uncemented Biomet glenoid components showed medial migration. None humeral components showed migration. Two times a screw breakage was seen. Revision surgery was performed in two patients with subdislocation in the Biomet-group; a thicker humeral head was placed both times. One with good result and one re-subdislocated due to a lesion of the brachial plexus.

Discussion: in 24 total shoulder arthroplasties no loosening of the humeral component occured. Loosening was seen in two glenoid components (8, 3%) although there was no indication to perform revision surgery. In these two cases a decreasing shoulder function was found. According to the pre-operative situation the range of motion post-operatively was unchanged but pain was obviously less.

Introduction

Total hip arthroplasty (THA) is the only successful treatment for patients in whom the hip joint is destroyed by inflammatory arthritis. Due to the effects of both the disease and its treatment elevated rates of complications and of aseptic loosening have been described. Whether with modern uncemented hip prostheses the results can be improved is not fully known. Therefore, we decided to carry out a prospective study.

Material and methods

At the introduction of a new press-fit acetabular component a prospective study on the results of uncemented THA was started. From 1995 to 1999 85 primary THAs were carried out in 72 patients (57 women, 15 men) suffering from inflammatory arthritis. Diagnosis: RA 76, adult-onset Still 4, JIA 3, miscellaneous 2. Mean age at operation was 60 years (SD 15. 9). Clinically, the Harris Hip Score was used for evaluation. Radiographically, the Larsen classification was used and at follow-up radiolucencies and signs of migration were registered.

The implants used in this study were the EPF-PLUS® acetabular component and the SL-PLUS® femoral component (PLUS Endoprothetik AG, Rotkreuz-CH). The EPF-PLUS® acetabular component is a novel modular press-fit cup. Its shell has a triple radius profile on cross-section, thereby creating a gradual lowering of the polar part of the cup. This produces a small gap of about 2 mm. between the acetabulum and the pole of the cup. Therefore, forces are mainly transmitted to the peripheral part of the acetabulum, leading to an enhanced primary stability. Originally, the shell had a gritblasted surface for osseointegration. Since 1996, the outer surface of the cup has been coated with a ground layer of pure titanium and a superficial layer of a crystalline hydroxyapatite (Ti-HA). The gritblasted version was used in 14 hips (1995–1996), the Ti-HA coated version in 71 hips. In 68 hips the cup was implanted by press-fit fixation, in 17 screws were added.

Results

Larsen classification was as follows: 0-1: 6; 3: 17; 4: 60; 5: 2. At follow-up, 5 patients (6 THAs) were deceased. Deep infection required revision in one hip. Another revision was carried out for recurrent dislocations. One grit-blasted cup developed late subsidence and was revised almost 4 years postoperatively. One Ti-HA coated cup failed early due to severe acetabular bone loss. Finally, one femoral component developed a varus tilt and became symptomatic 2 years after implantation, requiring revision. In all 62 patients with 74 THAs in follow-up cup and stem are functioning well, both clinically and radiographically. Harris Hip Score increased from 36. 6 (SD 17. 7) to 87. 9 (SD 11. 8).

Discussion

The medium-term results of the EPF®-PLUS cup show that its primary stability is good and that, as the polar gap rapidly disappears, osseointegration is secure. Only severe acetabular deficiency appears to be a contra-indication for this implant. Also, the SL-PLUS® stem performs well in inflammatory arthritis.