[Differential therapy for the rheumatoid shoulder]

Abstract

Despite frequent involvement, the rheumatoid shoulder is neglected in operative treatment of the upper extremities. The slow course of omarthritis, the compensation mechanism of scapulothoracic motion and neighbouring joints as well as dominating disabilities of the lower extremities and the rheumatoid hand are possible explanations. The pattern of destruction of the rheumatoid shoulder is characterized by progressive joint and soft tissue deterioration. Soft tissue involvement determines the course of the shoulder joint. The subacromial space is a common and early site for rheumatoid involvement, often leading to bursitis, tenosynovitis of the biceps tendon and rotator cuff rupture. Sonography and MRI enable the early detection of subacromial and glenohumeral pathology before deterioration is visible radiologically. Surgical intervention in patients with rheumatoid arthritis of the shoulder is based on the degree of radiological destruction according to Larsen, the natural course of the shoulder joint and the soft-tissue condition. The goals of surgery are to relieve pain, increase motion and restore shoulder function. Surgery should be carried out early in the course of the disease, thus determining the long-term prognosis and the remaining surgical options. Depending on the pattern of destruction of the rheumatoid shoulder, the options for treatment can be divided into early and late procedures.Joint-preserving surgery is indicated in the early stages of radiological destruction according to Larsen classification O-III, whereas the late stages of destruction (Larsen IV-V) require reconstructive surgery. The introduction of arthroscopic and semiarthroscopic techniques has improved the acceptance of early synovectomy for the rheumatoid shoulder, but there is still a place for open synovectomy in patients with extensive soft-tissue repair and bone-remodelling procedures. Arthroscopic and open synovectomy are supplementary and noncompetitive surgical procedures for the rheumatoid shoulder. With proceeding bone and soft-tissue destruction corresponding to Larsen stage IV and V, synovectomy is not successful and reconstructive surgery is necessary. Resection-interposition-arthroplasty (RAIP) remains a controversial alternative to arthroplasty in young patients with sufficient bone stock and a reconstructable rotator cuff. The success of cup-replacement will additionally restrict the indications for RAIP. RIAP remains a possible salvage procedure after aseptic and septic loosening of shoulder arthroplasty. Glenohumeral replacement arthroplasty has become the procedure of choice in reconstructive surgery of the shoulder. The severity of soft-tissue and bone destruction determines the choice of shoulder prosthesis. Current modular shoulder systems with increased numbers of humeral-head stem combinations are calculated to achieve a better adjustment of the soft-tissue tension and to optimize the adaptation between head geometry and the natural shape of the glenoid.The surrounding soft-tissue structure, especially the condition of the rotator cuff, is very important for the functional recovery after shoulder arthroplasty. We prefer a hemiarthroplasty of the rheumatoid shoulder joint to avoid critical glenoid fixation. Patients with irreparable rotator cuff tears and severe glenohumeral arthritis remain a difficult challenge in shoulder surgery and the ideal procedure has not yet been found.Pain relief and a modest increase in active motion are the main goals in operative treatment. Bipolar shoulder arthroplasty represents an adequate alternative to currently favoured hemiarthroplasty in patients with cuff-deficient shoulders.