Is the humeral stem useful in anatomic total shoulder arthroplasty?

PURPOSE: Traditionally and since Neer, the humeral side of shoulder arthroplasty consisted of a stemmed component but the real need for stem fixation in total shoulder arthroplasty (TSA) has barely been investigated. The current study evaluated the clinical and radiological outcomes with a stemless TSA.

METHODS

Forty-seven patients, 20 female and 27 male patients with an average age of 63, were selected in four orthopaedic centres during a four year period, and implanted with a humeral head prosthesis with a three-fin design and titanium coating. Aetiologies were: primary osteoarthritis (29), fracture sequelae (12) and avascular osteonecrosis (6). Minimum follow-up was two years (range 24-51 months). The patients were evaluated with the Constant score (CS) and radiological exams.

RESULTS

Two patients had revision of the implants, one for persistent pain and one for secondary massive rotator cuff tear. At the final follow-up, the mean CS was 69, with an average gain of 36. All parameters improved with a foremost in pain relief. Mean satisfaction rate was 87%. Average anterior active elevation was 131° with a gain of 48. Radiologic evaluations showed stable implants in all cases. However, 17 cases demonstrated radiolucent areas, particularly superior and lateral to the implant, which neither decreased nor increased with time. No revisions were related to humeral component loosening.

CONCLUSIONS

Stemless TSA provides the same results as compared to TSA with a humeral stem. We are still unsure as to the nature of the lucent zones and we are continuing our investigation to better understand this radiological phenomenon.