The long-term results of shoulder hemiarthroplasty in irreducible four-part fracture-dislocation of the proximal humerus without rotator cuff tear arthropathy.

PURPOSE: Although there are concerns about nonunion of the greater tuberosity or shoulder weakness, hemishoulder arthroplasty (HSA) is a viable treatment option for irreducible four-part proximal humerus fractures-dislocation without rotator cuff tear arthropathy. This study aims to analyze the long-term radiological and functional outcomes of HSA.

METHODS

This study enrolled 36 patients who underwent HSA due to irreducible four-part proximal humerus fracture-dislocation without rotator cuff tear arthropathy between March 2005 and May 2020. The exclusion group included 10 reverse total shoulder arthroplasty patients. The mean age and mean follow-up period were 68.6 years old and 48.6 months, respectively. Radiological assessments, such as vertical and horizontal greater tuberosity position, greater tuberosity healing, and implant position, were evaluated. Clinically, American Shoulder and Elbow Surgeons Score (ASES), Constant-Murley Score (CMS), and range of motion were evaluated.

RESULTS

The greater tuberosity union rate was 55.6% (n = 20), with 44.4% (n = 16) experiencing nonunion, malunion, and bone resorption. The mean vertical and horizontal greater tuberosity positions showed significant difference at last follow-up compared to immediate postoperation. The retroversion of the implant was 23.8 ± 4.61°, and the acromio-humeral interval was 7.6 ± 1.34 mm. The mean last follow-up ASES and CMS were 39.5 ± 4.03 and 55.4 ± 10.41, respectively. The mean active forward flexion, abduction, internal rotation, and external rotation were 100.9 ± 15.04°, 92.5 ± 14.47°, 44.2 ± 12.83°, and 42.5 ± 15.32°, respectively.

CONCLUSION

In long-term follow-up, the greater tuberosity was superiorly migrated and externally rotated. Active forward flexion and abduction in the last follow-up were significantly limited. However, in terms of pain relief, a satisfactory result was seen.