[Height control in shoulder hemiarthroplasty for treatment of proximal humerus fractures].

Objective: To evaluate methods of reduction using fragments of the greater tuberosity, and determine the clinical efficacy of humeral head replacement prosthesis height for proximal humerus fractures.

Methods: A retrospective study of patients with proximal humerus fractures who were treated and followed up from January 2015 to December 2019, 19 patients met the indications for humeral head replacement, including 7 males and 12 females;8 on the left side and 11 on the right side. The age ranged from 58 to 84 years old with an average of (71.5±5.8 ) years old. The time from injury to operation 3 to 18 d with an average of (7.9±4.3) d. According to Neer's classification, there were 2 cases of three-part fractures with dislocations and 17 cases of four-part fractures, including 6 cases with dislocation and 2 cases with head splits. All 19 patients used the modular prosthesis. The greater tuberosity fracture fragments were reduced to determine the distance from the apex of the greater tuberosity to the humerus marking point. This distance was used as the standard for the height of the prosthesis. One year after the operation, the Constant-Murley score and the University of California, Los Angeles (UCLA) shoulder score were used to evaluate the functional status of the shoulder joint and patient satisfaction.

Results: The 19 patients were followed up from 12 to 58 months with an average of (31.9±14.2) months. The length of the upper arm was 26 to 32 cm after the operation, two-sided comparison error <0.5 cm. Anteroposterior and lateral X-ray films of the shoulder joint at 3 months after operation showed that the fracture fragments were all healed. After one year follow-up, the Constant-Murley score was 80.8±8.9, and the UCLA score was 27.9±4.8. Patient satisfaction rate was 89.5%(17/19).

Conclusion: The greater tuberosity fracture fragments reduction technique, which use the distance from the apex of the greater tuberosity of humerus to the humeral marking point as the standard for the height of the prosthesis, is a simple and effective way with good outcomes in shoulder hemiarthroplasty for treatment of proximal humerus fractures.