Tuberosity position correlates with fatty infiltration of the rotator cuff after hemiarthroplasty for proximal humeral fractures.

HYPOTHESIS

This study investigates the correlation between tuberosity positioning, fatty infiltration of the rotator cuff, and clinical outcome after hemiarthroplasty for proximal humeral fracture.

MATERIALS AND METHODS

Twenty patients with a mean age of 70.8 +/- 9.9 years were evaluated at a mean of 19.8 +/- 9.4 months. Evaluation included assessment of the Constant score (CS); Disabilities of the Arm, Shoulder and Hand (DASH) score; radiographic evaluation; and computed tomography to classify healing of the tuberosities and changes in the rotator cuff. Fatty degeneration of the cuff was classified according to the Goutallier classification as stage 0 to 4. Tuberosity positioning was classified as mal-positioning of less than 0.5 cm., 0.5 to 1 cm., >1.0 cm., or not healed.

RESULTS

The mean Constant Score (CS) of patients with greater tuberosity displacement of <0.5 cm was significantly higher than the CS of patients with > or =0.5 cm displacement and non-united greater tuberosities. The CS of patients with greater tuberosity displacement of 0.5 to 1 cm was significantly higher than that in patients with non-united greater tuberosities. For the lesser tuberosity, patients with displacement of <0.5 cm showed significantly higher outcome scores than patients with displacement of >1 cm and non-united lesser tuberosities. There was a significant correlation between fatty infiltration of the supraspinatus and infraspinatus muscles and greater tuberosity malposition and between fatty infiltration of the subscapularis and lesser tuberosity malposition.

CONCLUSION

Fatty infiltration of the cuff was significantly associated with lower clinical scores. Tuberosity positioning and healing are critical for improved clinical outcomes after hemiarthroplasty for proximal humeral fractures.