Numerical and Experimental Investigations of Humeral Greater Tuberosity Fractures with Plate Fixation under Different Shoulder Rehabilitation Activities

The incidence of humerus greater tuberosity (GT) fractures is about 20% in patients with proximal humerus fractures. This study aimed to investigate the biomechanical performances of the humerus GT fracture stabilized by a locking plate with rotator cuff function for shoulder rehabilitation activities. A three-dimensional finite element model of the GT-fracture-treated humerus with a single traction force condition was analyzed for abduction, flexion, and horizontal flexion activities and validated by the biomechanical tests. The results showed that the stiffness calculated by the numerical models was closely related to that obtained by the mechanical tests with a correlation coefficient of 0.88. Under realistic rotator cuff muscle loading, the shoulder joint had a larger displacement at the fracture site (1.163 mm), as well as higher bone stress (60.6 MPa), higher plate stress (29.1 MPa), and higher mean screw stress (37.3 MPa) in horizontal flexion rehabilitation activity when compared to that abduction and flexion activities. The horizontal flexion may not be suggested in the early stage of shoulder joint rehabilitation activities. Numerical simulation techniques and experimental designs mimicked clinical treatment plans. These methodologies could be used to evaluate new implant designs and fixation strategies for the shoulder joint.

Surgical fixation of isolated greater tuberosity fractures of the humerus- systematic review and meta-analysis

OBJECTIVES

A systematic review was undertaken based on PRISMA guidelines to study the results of surgical treatment of Greater Tuberosity fractures of the Humerus by different techniques (Open, Percutaneous or Arthroscopic) and using different fixation devices (Sutures, Screws and Plates).

DATA SOURCES

Literature searches were performed for studies in English on four online databases (MEDLINE®, Embase®, Ovid® Emcare and CINAHL®) using a pre-planned search strategy.

STUDY SELECTION

Studies were screened against pre-decided inclusion and exclusion criteria. 24 articles were eligible for inclusion involving 562 patients in all.

DATA EXTRACTION

A template was used for collection of relevant data regarding the study design, demographics, fracture characteristics, surgical techniques and implants used, outcomes, complications and re-operations. Methodological quality was assessed using a modified Coleman Methodology Score.

DATA SYNTHESIS

Pooled analysis was conducted for (1) complications/reoperations of different devices; and (2) reported results using standard outcome measures of various techniques. Results were pooled using inverse variance method. When pooling proportions, we used arcsine transformation to account for zero events.

CONCLUSION

Use of screws was associated with higher rates of total complications (23.7%) as well as reoperations (13.2%), compared to sutures (14.2%; 2.6%) and plates (10.6%; 4.1%). In a subgroup analysis, use of low-profile plates (LPPs) was associated with the lowest rates of total complications (4.97%). The superiority of any surgical technique could not be established using the pooled Constant or ASES scores because there was lack of uniformity in the reporting of outcome measures. Our analysis of complications of the various fixation devices dissuades the use of screws and favours the use of low-profile plates. There is a need for prospective studies comparing arthroscopic suture fixation with open low-profile plate fixation of GT fractures.