Fifteen-year results of the Müller CoCrNiMo straight stem.

Between September 1980 and May 1982, 112 primary unilateral total hip arthroplasties with the original cemented M. E. Müller Straight stem (manufactured from Protasul-10, a CoCrNiMo alloy) were inserted in 109 consecutive patients, all combined with non-cemented, non-coated polyethylene RM cups. Forty-three patients (40%) died during the follow-up period, all with the implant in place. Of the 66 surviving patients, 2 (1.8%) were lost to follow-up, and 7 (6.3%) were unable to attend the 15-year clinical and radiological follow-up. Eight stems (7.3%) had to be revised for aseptic loosening and 3 stems (2.7%), for septic loosening. The 15-year survivorship of the Müller Straight stem regarding aseptic loosening is, therefore, 92.7%. Forty-six patients with 49 total hip replacements could be evaluated clinically and radiologically after 15 years. The mean duration of clinical follow-up for these 46 patients (42.2%) was 14.8 years (range 12.8-16.5 years). There were 22 women (48%) and 24 men (52%). The mean age at the time of the operation was 62 years (range 38-80 years), and 78 years (range 59-93 years) at the time of the latest follow-up. The mean Harris Hip Score at the latest follow-up evaluation of the 49 hip joints was 85 points (range 34-100 points). Of the 46 patients, 39 (85%) had a good or excellent clinical result. Radiographic follow-up was performed for 49 hips: 35 (70%) had linear or focal osteolysis in one or more zones of the stem, but only 4 (8%) had evidence of definitive loosening (linear radiolucency of over 2 mm all around the stem). Subsidence of over 2 mm was found in 20 hips (41%), 6 of them within the cement mantle. There was no correlation between subsidence and pain. The cause for the poor results is primarily the high rate of aseptic loosening of the non-coated, non-cemented all-polyethylene RM cups, with a loosening rate of 63% and a revision rate of 25% after 15 years.

Discoid lateral meniscus in children. Long-term follow-up after total meniscectomy.

We retrospectively reviewed the long-term results of total meniscectomy performed in seventeen knees (fourteen children) to treat a discoid lateral meniscus. The mean duration of follow-up was 19.8 years (range, 12.5 to 26.0 years). On the basis of the rating system of the International Knee Documentation Committee, seven knees were normal (grade A), six were nearly normal (grade B), three were abnormal (grade C), and one was severely abnormal (grade D) at the latest follow-up evaluation. Ten of the seventeen knees had clinical symptoms of osteoarthrosis. Radiographs were available for fifteen of the knees at the latest follow-up evaluation. Eleven of the treated knees could be compared with the uninvolved, contralateral knee. Ten knees had osteoarthrotic changes, such as flattening of the lateral femoral condyle, formation of a ridge along the lateral femoral condyle, and spurring and sclerosis of the tibial plateau. Osteochondritis dissecans developed in two knees, nine and twenty years after the initial meniscectomy.

[Spinal pseudarthroses]. / Pseudarthrosen im Bereich der Wirbelsäule.

Pseudarthroses of the spine are classified into congenital, acquired non-traumatic, posttraumatic and postoperative (iatrogenic) pseudarthroses. The various types of non-unions of the spine are described according to their clinical and radiological appearance. In line with their clinical importance, special attention with respect to the operative treatment is given to non-union of the axis of C2 and to spondylolysis. For the pseudarthrosis of the dens a posterior fusion according to Gallie-Brooks is recommended, in spondylolysis without marked slipping a "direct repair" should be considered in young patients.

[Expenses and risk of artificial knee joint: a look backward to a 20-year clinical experience]. / Aufwand und Risiken künstlicher Kniegelenke: Rückblick auf 20 Jahre praktische Erfahrung.

Costs and risks of implantation of prosthetic knee joints are analyzed in this retrospective study. From 1974-1993 514 primary and 34 revision arthroplasties were done in this hospital, all by the same surgeon. 98% of the patient protocols were available and analyzed, but no systematic follow-up was attempted. 82% of the patients were female; mean age at operation was 74 years. Joint destruction was caused by osteoarthritis in 75%, aseptic osteonecrosis in 10%, rheumatoid arthritis in 9% and posttraumatic arthritis in 3.5%. 75% of the patients were obese and had a body mass index > 25 kg/m2. Non-constrained unicompartmental type prostheses were used in 66%, the non-constrained multicompartmental type in 10% and the constrained total rotation knee (Engelbrecht) in 24%. Hospital mortality rate was 0.55% due to myocardial infarction and pulmonary embolism. 3 patients died of septic prosthetic joint infections 5, 7 and 71/2 years after surgery. Perioperative morbidity, typical of the age group above 70 years, was mainly due to cardiovascular and thromboembolic events and gastrointestinal bleeding. Early infection during the first postoperative year was encountered in 3 constrained total knees, but none in nonconstrained type. The calculated operative infection rate was 2.4% for the constrained type, zero for the non-constrained type, and 0.5% for the whole series. Late prosthetic infections occurred in 8 patients up to 12 years after surgery. In comparing non-constrained unicondylar and hinged types of joint replacement, the non-constrained sledge prosthesis involves considerably lower costs in terms of duration of surgery, hospital stay, blood loss, price of the implant, infection rate and difficulties of revision arthroplasty. Lower costs and risks favour the smaller unicondylar implant for use in localized degenerative or necrotic destruction, particularly of the medial compartment of the knee. Semi-constrained total condylar systems are used for more extensive degeneration without evident instability. The indication for hinged endoprostheses is restricted to revision arthroplasty and grossly unstable knees.