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Five patients with rheumatoid arthritis (age 28-60 years) underwent wrist joint arthroplasty with individually designed artificial joint mechanisms, anchored to bone using the osseointegration principle. We report on the result from a 4 to 6.5 year follow-up with special emphasis on the fixation of the prosthesis to bone. There was no bone resorption or loosening of screws. Osseointegration of the titanium screws occurred in all cases and persisted throughout the observation period, although scattered lytic zones could sometimes be seen around the screws. The clinical results were satisfactory with pain relief and maintenance of a functional range of movement. The principle has prospects for fixation of a wrist joint mechanism to bone, although the presently used joint mechanism requires further refinement.

Twenty-four posterior mandibular segments in 18 patients were operated on placing implants after mobilisation of the neurovascular bundle. Two different surgical techniques, transposition and lateralization was used. The overall survival rate of fixtures was 92.1%. Performing lateralization resulted in 100% success, while transposition resulted in 80% stable fixtures in the involved segments. The mean time to full restoration of nerve function was 3.8 weeks after lateralization and 5.7 weeks after tranposing the nerve. Three patients exhibited persisting slight hyposthesia, but all, subjectively negligible disturbances in nerve function.

The osseointegration concept has been used for fixation of 68 MP joint endoprostheses in 31 patients operated on at the Department of Hand Surgery, Malmö General Hospital during the period 1988-1992. The indications were rheumatoid arthritis (50 joints), primary osteoarthrosis (three joints), post-traumatic osteoarthrosis (three joints), post-traumatic osteoarthrosis (five joints), post-infectious osteoarthrosis (seven joints) and joint deformities secondary to spastic conditions (three joints). The average follow-up time was 2.5 years (6-54 months). The surgical procedure included resection of the joint followed by introduction of screw-shaped titanium fixtures into the bone marrow cavities of the metacarpal and the phalangeal base. Rheumatoid cases usually required grafting of cancellous bone and marrow from the iliac crest. At the same time a flexible constrained silicone spacer was connected to the titanium fixtures in such a way as to allow later replacement of the spacer if accessory. The average active range of motion (ROM) was 57 degrees in the rheumatoid cases and 50 degrees in all cases. Radiological and clinical osseointegration occurred in every case, and there were no clinical signs of loosening. In four cases (6%) there was a fracture of the joint mechanism. Patient satisfaction was high, with pain relief, increased range of motion, improved hand function and good cosmetic appearance.

16 consecutive totally edentulous patients were provided with 95 osseointegrated titanium fixtures in 7 upper and 9 lower jaws. Facultatively removable bridges were later connected to abutments, attached to the fixtures. The marginal soft and hard tissue reactions were investigated at a baseline examination and after 6, 12, 21, 30 and 39 months by standardized clinical and radiographical methods. At the last examination, microbiological samples and gingival biopsies were also analysed. The % ratios of abutments without plaque, 70-75%, and without any gingivitis, 80-85%, were almost constant throughout the study. The mean probing depth was 2.9 mm at the final examination. About 75% of all probing depths were 3 mm or less and none exceeded 5 mm. The bridge-gingiva distances increased during the investigation. Attached gingiva surrounded 65% of the buccal and lingual abutment surfaces. Only 0.9 mm marginal bone was lost as a mean during the first year and not more than 0.05 mm annually for the next 2 years. After 6 months, no significant changes in marginal bone levels occurred. The perifixtural bone gradually became more radiopaque, especially marginally in upper jaws, indicating a successive load-related remodelling. The microbiotia comprised coccoid cells and non-motile rods to 93% in 32 samples. Healthy tissues were present in 35% of the 14 soft tissue biopsies. In a further 29%, only a slight inflammation was observed. No constant correlations could be established for any of the investigation parameters used. It is concluded that the marginal soft tissue reactions were mild and not significant for a progressive periodontitis. Mobility tests of separate fixtures combined with quantitative and qualitative standardized radiological examinations of the surrounding bone appear to provide a truer comprehension of longitudinal events at osseointegrated implants than conventional clinical soft tissue observations. The prognosis for the osseointegrated implants appears excellent, especially with regard to the microbiotia, the small marginal bone height changes, and the radiological indications of remodelling in the perifixtural bone.

20 totally edentulous patients, provided with 24 facultatively removable fixed bridges (13 upper and 11 lower jaws) were recalled. The material consisted of 125 osseointegrated titanium fixtures with a mean observation time of 7.6 years (range 6 months to 15 years). The marginal tissues were examined by conventional periodontal clinical methods and standardised radiography. Microbiological samples and biopsies of the soft marginal barrier tissues were retrieved for dark-field and histological analysis, respectively. The percental ratios of abutment surfaces devoid of plaque and without signs of gingivitis, were 46% and 20%, respectively. In contrast to earlier studies, the presence of plaque and gingivitis was significantly correlated. This relationship was probably due to more plaque being present. The mean probing depth was 3.8 mm. In 40% of the measurements, the probing depths were 3 mm or less, and in 45% between 4 and 5 mm, whereas they only in 15% were 6 mm or more. They were greater in upper than in lower jaws and were found to be significantly correlated with gingivitis. Attached gingiva surrounded about 51% of the buccal and lingual abutment surfaces. The marginal bone height changes were very small during the follow-up period (0.07 mm annually). Coccoid cells and non-motile rods dominated the microflora to 94% in the 48 samples taken. Out of the 19 biopsies, 58% showed healthy mucosa and a further 37% had the lowest inflammation score. The indications of gingivitis and deep pockets at the clinical examination were not found accompanied by an accelerated marginal bone loss, nor by a microflora or histological changes indicative of periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)