OUTCOME OF SHOULDER PROSTHESIS FOR SEQUELAE OF FRACTURE OF THE PROXIMAL HUMERUS WITH NONUNION OF THE SURGICAL NECK

Abstract

Purpose: Nonunion of the surgical neck of the humerus can occur after orthopaedic or poorly-adapted surgery after displaced subtuberosity or cephalotuberosity fracture. The purpose of this study was to report functional and radiographic outcome after treatment with shoulder prosthesis.

Material and methods: Twenty-two patients who had a non-constrained shoulder prosthesis were included in this retrospective multicentric study. Mean age was 70 years and mean follow-up was 45 months (range 2 – 9 years). The initial fracture had two fragments in six patients and was a three-fragment fracture involving the head and the tubercle in thirteen and a four-fragment fracture in three. Orthopaedic treatment was given in ten cases and surgical osteosynthesis was used in twelve. Time from fracture to implant insertion was 20 months. The deltopectoral approach was used for 21 humeral implants and one total shoulder arthroplasty (glenohumeral degeneration). The tuberosities were fixed to the cemented humeral stem and a crown of bone grafts were placed around the nonunion of the surgical neck. All patients were reviewed after a minimum of two years and assessed with the Constant score and x-rays.

Results: The absolute Constant score improved from 23 reoperatively to 39 postoperatively with an anterior elevation of 53° to 63°. Pain score (from 3 to 9, p = 0.001) and external rotation (from 13° to 28°, p = 0.01) were significantly improved. Forty-five percent of the patients were satisfied and 55% were dissatisfied. The type of initial treatment, type of initial fracture, and time before implantation of the prosthesis did no affect final outcome. The complication rate was 36% (eight patients), and led to five revision procedures. The radiographic work-up disclosed six cases of persistent nonunion of the greater tuberosity, two proximal migrations of the prosthesis, and one humeral loosening.

Conclusion: Outcome of shoulder prosthesis for sequela after fracture of the proximal humerus with nonunion of the surgical neck is poor. No improvement in anterior elevation, force, or motion was achieved. Shoulder prosthesis for sequelae of fracture of the proximal humerus with nonunion of the surgical neck should be considered as a “limited-objective” indication only providing beneficial pain relief.