Abstract
Introduction
The value of the preoperative radiograph of the rheumatoid shoulder is underestimated for defining the moment for arthroplasty. Larsen grades 4 and 5 are widely used as radiological criterium, but this grading system is not sufficient for staging important surgical aspects as proximal migration and medialisation of the humeral head. The purpose of this study is to analyse the proximal migration and medialisation in severely destructed shoulders (Larsen 4 and 5) and to correlate this with the clinical and per-operative findings to optimize the timing for shoulder arthroplasty.
Methods
From a large group of patients with a shoulder arthroplasty those were selected who had preoperatively an involvement of the shoulder graded as Larsen 4 or 5. 104 Rheumatoid patients were selected (29 male, 75 female). The average age was 60 years (range 25–83 yrs). All patients were preoperatively clinically scored with the HSS-score, a 100 points scoring system, which assesses pain, function, power and range of motion. The radiographs were scored for the following items: gleno-humeral joint space, bone loss of glenoid, destruction of the humeral head, proximal migration and involvement of the AC-joint. The most important peroperative items were the quality of the rotator cuff and the glenoid bone mass.
Result
69 Shoulders were graded as Larsen 4 and 35 as Larsen 5. Medialisation by bone loss of the glenoid was moderate in 65% and severe in 13. 6% of the shoulders. Proximal migration was moderate in 22% and severe in 39% of the shoulders. There was no significant correlation between medialisation and proximal migration. The rotator cuff was torn in 44% of the shoulders. Although a torn cuff was significantly related with proximal migration there were many cases with maximal proximal migration with an intact cuff. The clinical scores were not significantly related with the radiographic deterioration of the shoulder.
Discussion
Because of the discrepancy between clinical findings and radiographic destruction of the rheumatoid shoulder, the radiographic findings have to play a more important role in the indication of shoulder arthroplasty to achieve a better functional and long-term result.
