Aims

Shoulder arthroplasty using short humeral components is becoming increasingly popular. Some such components have been associated with relatively high rates of adverse radiological findings. The aim of this retrospective review was to evaluate the radiological humeral bone changes and mechanical failure rates with implantation of a short cementless humeral component in anatomical (TSA) and reverse shoulder arthroplasty (RSA).

We hypothesised that a large acromial cover with an upwardly tilted glenoid fossa would be associated with degenerative rotator cuff tears (RCTs), and conversely, that a short acromion with an inferiorly inclined glenoid would be associated with glenohumeral osteoarthritis (OA). This hypothesis was tested using a new radiological parameter, the critical shoulder angle (CSA), which combines the measurements of inclination of the glenoid and the lateral extension of the acromion (the acromion index).

The CSA was measured on standardised radiographs of three groups: 1) a control group of 94 asymptomatic shoulders with normal rotator cuffs and no OA; 2) a group of 102 shoulders with MRI-documented full-thickness RCTs without OA; and 3) a group of 102 shoulders with primary OA and no RCTs noted during total shoulder replacement. The mean CSA was 33.1° (26.8° to 38.6°) in the control group, 38.0° (29.5° to 43.5°) in the RCT group and 28.1° (18.6° to 35.8°) in the OA group. Of patients with a CSA > 35°, 84% were in the RCT group and of those with a CSA < 30°, 93% were in the OA group.

We therefore concluded that primary glenohumeral OA is associated with significantly smaller degenerative RCTs with significantly larger CSAs than asymptomatic shoulders without these pathologies. These findings suggest that individual quantitative anatomy may imply biomechanics that are likely to induce specific types of degenerative joint disorders.

Cite this article: Bone Joint J 2013;95-B:935–41.

There are no long-term published results on the survival of a third-generation cemented total shoulder replacement. We describe a clinical and radiological study of the Aequalis total shoulder replacement for a minimum of ten years. Between September 1996 and May 1998, 39 consecutive patients underwent a primary cemented total shoulder replacement using this prosthesis. Data were collected prospectively on all patients each year, for a minimum of ten years, or until death or failure of the prosthesis. At a follow-up of at least ten years, 12 patients had died with the prosthesis intact and two had emigrated, leaving 25 available for clinical review. Of these, 13 had rheumatoid arthritis and 12 osteoarthritis. One refused radiological review leaving 24 with fresh radiographs.

Survivorship at ten years was 100% for the humeral component and 92% for the glenoid component. The incidence of lucent lines was low. No humeral component was thought to be at risk and only two glenoid components. The osteoarthritic group gained a mean 65° in forward flexion and their Constant score improved by a mean 41.4 points (13 to 55). The rheumatoid group gained a mean of 24° in flexion and their Constant score improved by 29.4 points. This difference may have been due to failure of the rotator cuff in 75% of the patients with rheumatoid arthritis.

Thus a third-generation total shoulder replacement gives an excellent result in patients with osteoarthritis and an intact rotator cuff. Patients with rheumatoid arthritis have a 75% risk of failure of the rotator cuff at ten years.

We carried out a prospective, randomised controlled trial on two groups of 40 patients with painful calcific tendonitis and a mean age of 48.4 years (32.5 to 67.3). All were to undergo arthroscopic removal of the calcific deposit within six months after randomisation. The 40 patients in group I received ultrasound-guided needling followed by high-energy shock-wave therapy and the 40 in group II had shock-wave therapy alone. In both groups one treatment consisting of 2500 impulses of shock waves with an energy flux density of 0.36 mJ/mm² was applied. The clinical and radiological outcome was assessed using the 100-point Constant shoulder scoring system and standardised radiographs. The mean follow-up was 4.1 months and no patient was lost to follow-up.

Both groups had significant improvement in their Constant shoulder score. Radiographs showed disappearance of the calcific deposit in 60.0% of the shoulders in group I and in 32.5% of group II (p < 0.05). Significantly better clinical and radiological results were obtained in group I than in group II. Arthroscopic removal of the deposit was avoided in 32 patients of group I and in 22 of group II. No severe side-effects were recorded.

Ultrasound-guided needling in combination with high-energy shock-wave therapy is more effective than shock-wave therapy alone in patients with symptomatic calcific tendonitis, giving significantly higher rates of elimination of the calcium deposits, better clinical results and reduction in the need for surgery.

We reviewed 12 patients with primary glenoid dysplasia. Ten were assessed clinically and two from case notes and radiographs. We identified two groups according to the age at onset of symptoms. The first (seven patients) consisted of boys and younger men, all of whom developed symptoms before the age of 40 years. All four children were free from pain, whereas the three adults in this group had varying degrees of this. Four patients had symptoms of instability. The second group consisted of older men (five patients) all of whom had noted the onset of symptoms, in the form of pain and stiffness, after the age of 40 years. All five had radiological evidence of osteoarthritis. Although the four children in our study had minimal symptoms, all eight adults had ongoing shoulder pain and dysfunction, despite a specific rehabilitation programme. Four patients required surgery; one had posterior stabilisation for instability and three arthroplasties of the shoulder for osteoarthritis