Inverse shoulder prosthesis systems are available to compensate for irreparable dysfunction of the rotator cuff. The aim of this study is to evaluate the results after one-stage exchange operations of shoulder implants using the Delta Prosthesis and compare these with the preoperative status.

84 one-stage prosthesis exchanges were evaluated in this prospective analysis 0.5 to 4 years postoperatively. Symptoms of pain and functional results were recorded in a specially compiled follow-up questionnaire and also classified according the Constant and Murley shoulder score.

The mean age of the patients was 65.6 years (49–78 years). The current exchange operation was performed due to impingement caused by cranial migration of the implant head, cranio-ventral dislocation, periprosthetic infection, implant loosening and postoperative ankylosis of the shoulder joint. After the exchage operation with reimplantation of a Delta Prosthesis all patients had complete relief of pain or experienced tolerable pain. The function of the shoulder was markedly improved in all cases. The Constant and Murley shoulder score increased form the preoperative average of 29 to 58 points. The overall complication rate was 13.1%.

One-stage exchange of shoulder prostheses using inverse implants is a technically demanding, but standardised procedure for treating instability, dislocation, limited range of motion, loosening and infection in appropriate cases. The reliable reduction or complete elimination of pain has resulted in a high degree of satisfaction among patients. The final functional result is almost fully achieved as soon as three months postoperatively.

There are few reports in the literature of the diagnosis and treatment of the infected shoulder arthroplasty. Most deal with resection arthroplasty and two-stage exchange surgery. We present our results of one-stage exchange operation as treatment for the infected shoulder arthroplasty.

Our group comprised 16 patients (ten men, six women) with 16 infected arthroplasties. By the time of follow-up, two patients had died (mean 5.8 years), two could not be located and three had already undergone revision surgery. Nine patients were thus available for clinical examination and assessment.

The infections were largely caused by staphylococci, Propionibacterium species and streptococci. Two were early infections (within three months of surgery) and 14 were late infections. The mean follow-up was 5.8 years (13 months to 13.25 years) when the mean Constant-Murley score was 33.6 points and the mean University College of Los Angeles score 18.3 points.

Further revision was performed in three patients. One sustained a peri-prosthetic humeral fracture, another developed an acromial pseudarthrosis after transacromial surgery and the third suffered recurrent dislocations. No patient had a recurrence of infection.

A one-stage exchange procedure using antibiotic-loaded bone cement eradicated infection in all our patients and we suggest that such a procedure is at least as successful as either a resection arthroplasty or a two-stage exchange in the management of the infected shoulder arthroplasty.