Aims

Radiostereometric analysis (RSA) allows an extremely accurate measurement of early micromotion of components following arthroplasty.

Aims

The aims of this study were to evaluate the clinical and radiological outcomes of the Universal-2 total wrist arthroplasty (TWA) in patients with rheumatoid arthritis.

Resurfacing of the humeral head is commonly used within the UK to treat osteoarthritis (OA) of the shoulder. We present the results of a small prospective randomised study of this procedure using the Global CAP prosthesis with two different coatings, Porocoat and DuoFix hydroxyapatite (HA). We followed two groups of ten patients with OA of the shoulder for two years after insertion of the prosthesis with tantalum marker beads, recording pain, Constant–Murley and American Shoulder and Elbow Surgeons (ASES) outcome scores, and using radiostereometric analysis to assess migration. The outcomes were similar to those of other series, with significant reductions in pain (p = 0.003) and an improvement in the Constant (p = 0.001) and ASES scores (p = 0.006). The mean migration of the prosthesis three months post-operatively was 0.78 mm (0.51 to 1.69) and 0.72 mm (0.33 to 1.45) for the Porocoat and DuoFix groups, respectively. Analysis of variance indicated that the rate of migration reached a plateau after three months post-operatively in both groups. At follow-up of two years the mean migration was 1 mm (sd 1 (0.25 to 3.32)); in the Porocoat group and 0.8 mm (sd 0.4 (0.27 to 1.45)) in the DuoFix HA group. Significant migration of the prosthesis was seen in one patient who had received an anterior humeral bone graft. This prosthesis was later revised after 2.7 years.

The addition of a coating of HA to the sintered surface does not improve fixation of this prosthesis.

Cite this article: Bone Joint J 2014;96-B:1077–81.

This is a retrospective review of the results of the Acclaim total elbow replacement in 11 older patients aged ≥ 65 years with primary osteoarthritis of the elbow, with a mean follow-up of 57.6 months (30 to 86.4).

Significant reductions in pain and improvement in range of movement and function were recorded. Radiological review revealed two patients with 1 mm lucencies in a single zone, and one patient with 1 mm lucencies in two zones. No components required revision. There were no deep infections, dislocations or mechanical failures. Complications included one intra-operative medial condylar fracture and one post-operative transient ulnar neuropathy, which resolved.

This study demonstrates that the Acclaim prosthesis provides good symptomatic relief and improvement of function in patients with primary osteoarthritis, with low rates of loosening or other complications. This prosthesis can therefore be considered for patients aged ≥ 65 years with primary osteoarthritis of the elbow.

In a prospective study between 2000 and 2005, 22 patients with primary osteoarthritis of the shoulder had a total shoulder arthroplasty with a standard five-pegged glenoid component, 12 with non-offset humeral head and ten with offset humeral head components. Over a period of 24 months the relative movement of the glenoid component with respect to the scapula was measured using radiostereometric analysis.

Nine glenoids needed reaming for erosion. There was a significant increase in rotation about all three axes with time (p < 0.001), the largest occurring about the longitudinal axis (anteversion-retroversion), with mean values of 3.8° and 1.9° for the non-offset and offset humeral head eroded subgroups, respectively. There was also a significant difference in rotation about the anteversion-retroversion axis (p = 0.01) and the varus-valgus (p < 0.001) z-axis between the two groups. The offset humeral head group reached a plateau at early follow-up with rotation about the z-axis, whereas the mean of the non-offset humeral head group at 24 months was three times greater than that of the offset group accounting for the highly significant difference between them.

This study identified variables which influence the outcome of surgical management on 126 ununited scaphoid fractures managed by internal fixation and non-vascular bone grafting. The site of fracture was defined by a new method: the ratio of the length of the proximal fragment to the sum of the lengths of both fragments, calculated using specific views in the plain radiographs. Bone healing occurred in 71% (89) of cases. Only the site of nonunion (p = 1 × 10⁻⁶) and the delay to surgery (p = 0.001) remained significant on multivariate analysis. The effect of surgical delay on the probability of union increased as the fracture site moved proximally. A prediction model was produced by stepwise logistic regression analysis, enabling the surgeon to predict the success of surgery where the site of the nonunion and delay to surgery is known.

The Acclaim total elbow replacement is a modular system which allows implantation in both unlinked and linked modes. The results of the use of this implant in primary total elbow replacement in 36 patients, operated on between July 2000 and August 2002, are presented at a mean follow-up of 36 months (24 to 49). Only one patient did not have good relief of pain, but all had improved movement and function.

No implant showed clinical or radiological loosening, although one had a lucent area in three of seven humeral zones. The short-term results of the Acclaim total elbow replacement are encouraging. However, 11 patients (30.5%) suffered an intra-operative fracture of the humeral condyle. This did not affect the outcome, or the requirement for further surgery, except in one case where the fracture failed to unite. This problem has hopefully been addressed by redesigning the humeral resection guide. Other complications included three cases of ulnar neuropathy (8.3%) and one of deep infection (2.8%).

We have undertaken a prospective clinical and radiological analysis of 124 shoulder arthroplasties (113 patients) carried out for osteoarthritis. The clinical results showed improvement in the absolute Constant score and the American Shoulder and Elbow Surgeons score of 22 and 43, respectively. Both were statistically significant (p < 0.001). There was no significant difference in the scores after hemiarthroplasty and total arthroplasty in those patients with an intact rotator cuff.

When revision was used as the end-point for survival at ten years, survival of 86%, or 90% if glenoid components made of Hylamer sterilised in air were omitted, was obtained in primary osteoarthritis. The most common cause for revision in the hemiarthroplasty group was glenoid pain at a mean of 1.5 years; in the total arthroplasty group it was loosening of the glenoid at a mean of 4.5 years. Analysis of pre-operative factors showed that the risk of gross loosening of the glenoid increased threefold when there was evidence of erosion of the glenoid at operation. Shoulder arthroplasty should not be delayed once symptomatic osteoarthritis has been established and should be undertaken before failure of the cuff or erosion of the glenoid are present.

We divided 309 patients with an inflammatory arthritis who had undergone primary elbow replacement using the Souter-Strathclyde implant into two groups according to their age. The mean follow-up in the older group (mean age 64 years) was 7.3 years while in the younger patients (mean age 42 years) it was 12 years. Survivorship for three different failure end-points (revision, revision because of aseptic loosening of the humeral component, and gross loosening of the humeral implant), was compared in both groups.

Our findings showed that there was no significant difference in the incidence of loosening when young rheumatoid patients were compared with an older age group.

We reviewed the records and radiographs of 381 patients with rheumatoid arthritis who had undergone silastic metacarpophalangeal joint replacement during the past 17 years. The number of implants was 1336 in the course of 404 operations. Implant failure was defined as either revision or fracture of the implant as seen on radiography. At 17 years, the survivorship was 63%, although on radiographs two-thirds of the implants were seen to be broken. Factors which improved survival included soft-tissue balancing, crossed intrinsic transfer and realignment of the wrist. Surgery to the thumb and proximal interphalangeal joint had a deleterious effect and the use of grommets did not protect the implant from fracture.

We have performed a clinical and radiological analysis of 105 shoulder arthroplasties in patients with rheumatoid arthritis. The clinical results showed improvements in the Constant-Murley and Association of Shoulder and Elbow Surgeons score of 21 and 35, respectively. Both were statistically significant (p < 0.001). This improvement was maintained over a period of 8.8 years. There was no statistically significant difference in the scores after hemiarthroplasty and those after total arthroplasty. The presence of an intact rotator cuff was associated with improved function in both groups.

In spite of the use of an uncemented humeral stem, no implant was radiologically loose or at risk. There was lucency in a single zone in 14 implants. One glenoid component was at risk and 16 had lucency in a single zone. There was, however, a significant difference in the amount of lucency which was associated with pegged and keeled glenoid components (p = 0.005). In the group with hemiarthroplasty, two or more years after surgery there was superior migration of the humeral component by more than 5 mm in 18 shoulders (28%) and medial migration by more than 2 mm in eight (16%). Both superior and medial migration had an effect on the outcome. Revision was undertaken in four patients for persistent pain relating to medial migration. With revision taken as the endpoint for survival after eight years, 92% were found to be still in situ.

We have implanted 76 biaxial total wrist prostheses as a primary procedure in patients with rheumatoid arthritis of the wrist. A total of 66 was reviewed at a mean follow-up time of 52 months. Pain was relieved in 67% of the surviving wrist replacements. On the basis of the Hospital for Special Surgery scoring system, 49 wrists (74%) were graded as fair to excellent. More than half of the 27 patients who had an arthrodesis on the contralateral wrist would have preferred a second arthroplasty. Five replacements were revised or fused because of loosening and a further nine showed signs of radiological loosening, three of which were asymptomatic.

The probability of survival of the biaxial total wrist replacement at eight years was 83% with revision surgery as the terminal event, 78% with radiological loosening as the endpoint and 82% with dorsal migration and displacement from the metacarpal as the terminal event. There was a linear relationship between subsidence of the component and distal loosening. There was no evidence that the length of the stem of the carpal component, within the third metacarpal, affected any of the terminal events. The position and alignment of the carpal component within the bone at the time of surgery significantly affect the outcome and can be used to predict failure.

We undertook a radiological analysis of 186 standard Souter implants to determine survivorship and to analyse the pattern of failure in those needing revision. The implants had been inserted as a primary procedure in patients with rheumatoid arthritis of the elbow at our hospital over the last 12 years.

Taking revision as an endpoint, the survivorship after 12 years was 87%. If, however, revision and loosening, defined as the Hindex value equivalent to demarcation of 1 mm around the whole implant, are also included, the survivorship falls to 80%. Of the 24 implants revised, 18 (75%) were for problems with the humeral component, three (12.5%) with the ulnar component and three (12.5%) for instability.

Loosening of the humeral component occurred when the implant extended into the humerus, with the tip moving anteriorly on to the anterior humeral cortex. Our study indicates that loosening can be predicted by the rate of change in this angle of extension of the prosthesis.