We present our results of cementless total hip arthroplasty with a tapered, rectangular stem made of titanium-aluminum-niobium alloy. This implant is used since 1979 with only minor modifications. The design of the femoral component achieves primary stability through precision rasping and press-fit implantation.

Between October 1986 and November 1987, two hundred consecutive patients (208 hips) underwent total hip arthroplasty with this tapered, rectangular stem. In all cases the acetabular component was a threaded cup made of titanium.

At a minimum follow-up of twenty years eighty-seven patients were still alive. Sixty-seven patients (69 hips) were available for clinical and radiographic follow-up. The probability of survival of the stem was 0.96 (95% confidence interval, 0.91 to 0.98) and that of the cup was 0.72 (0.62 to 0.80). The probability of survival of both the stem and the acetabular component with revision for any reason as the end point was 0.71 (0.61 to 0.78).

Two stems have been revised due to aseptic loosening. We found various degrees of osteolysis around the acetabular and femoral component (61,7%). At the time of the 20-year follow-up no stem was deemed at risk for loosening.

The key findings of our twenty-year follow-up are the very low rate of revisions of the femoral component and the low rate of distal femoral osteolysis associated with this stem. Our data show that femoral fixation of the stem continues to be secure at a follow-up of twenty years.

In a randomised study, 28 patients with a mean age of 62.2 years (32 to 81) with osteoarthritis or avascular necrosis of the hip received either a ceramic-on-ceramic or a metal-on-metal total hip replacement. Apart from the liners the acetabular and femoral components were made of Ti-Al-Nb alloy. The serum aluminium and cobalt levels were measured before, and at one year after surgery.

The 15 patients in the ceramic-on-ceramic group had a median pre-operative aluminium level of 1.3 μg/l (0.25 to 8.4) and a cobalt level below the detection limit. At one year the aluminium level was 1.1 μg/l (0.25 to 2.3) and the cobalt level was 0.4 μg/l (0.15 to 0.7). The 13 patients in the metal-on-metal group had a median pre-operative aluminium level of 1.9 μg/l (0.25 to 4.4) and a cobalt level below the detection limit. At one year the median aluminium level was 0.9 μg/l (0.25 to 3.9) whereas the cobalt level was 1.4 μg/l (0.5 to 10.5). This increase in the cobalt level at one year was significant (p < 0.001).

Our findings indicate that ceramic-on-ceramic bearings do not cause elevated levels of serum aluminium in the first post-operative year.

The purpose of this study was to evaluate if there was a difference in the outcome of operative treatment for rotator cuff-tears in patients younger and older than the age of 60.

Thirty-eight patients (19 male, 19 female) underwent 40 procedures and were postoperatively evaluated 15 and 42 months after surgery. At the time of follow-up they had a physical examination that included the Constant score, radiograph in three planes and a questionnaire focused on the need for analgesics, nocturnal pain, and return to full activity (work and sports). Cuff tears were classified by the Harryman classification. Corresponding to the study design, patients were divided into two age groups: under the age of sixty years (51a, min. 44a, max. 58a, n=22) and patients sixty years of age and older (68,3a, min. 60a, max. 82a, n=16).

Active range of motion increased significantly in both age groups (p< 0.05) from 101° to 152° in abduction after the first 15 months after surgery and in anteversion from 117° to 155°. By the time of the second evaluation, abduction had decreased to 136° for abduction and 149° for anteversion. The results of functional assessment by the Constant score was 72 points after 16 months and after 42 months decreasing to 62 points in the group of patients under the age of 60, and from 71 to 66 points in the group of patients 60 years of age and older.

In both age groups there was a continuous increase in muscle force: from 4.35kp after 15 months to 4.5kp after 42 months in patients younger than 60, and from 2.24kp to 3.75kp in the older age group. Pain and the use of analgesic medication decreased significantly (p< 0.0001 and p=0.0003) in both age groups during the first 15 months after surgery and after 42 months had remained at the same low level. There was a correlation between extent of the cuff tear and results of functional assessment by the constant score. For patients with Harryman Type I cuff tears, mean score after 15 months was 78 points decreasing to a mean score of 65 points after 42 months. Harryman Type II cuff tears decreased from 74 to 70 points, with Type III cuff tears decreasing from 63 to 57 points.

Patients in the age group of 60 years and older had more similar benefits from operative treatment for rotator cuff-tears than the group under the age of 60. The best clinical result in both groups appeared during the first two years after surgery and decreased an average of 3.5 years postoperatively. The results of the Constant Score were influenced primarily by the size of the cuff tear.