Risk factors for intra-articular involvement in proximal humeral fractures.

INTRODUCTION: Identification of intra-articular involvement in proximal humeral fractures is important for operative decision making. The aim of this study was to identify the risk factors associated with intra-articular involvement in proximal humeral fractures. MATERIALS AND METHODS: One hundred consecutive three-dimensional computed tomography reconstructions of proximal humeral fractures were identified. The fracture lines were then accurately transcribed onto a two-dimensional superior view of the humeral head and each fracture was assessed for intra-articular involvement. Statistical analyses were undertaken to identify risk factors for intra-articular involvement and extent of involvement. Furthermore, for each risk factor, common fracture patterns were identified and compared to anatomical landmarks. RESULTS: Overall, 58% of the fractures involved the articular surface. High-energy mechanism, female gender, age ≥ 65, and posterior dislocation were risk factors for intra-articular involvement. Low-energy mechanism, female gender, age ≥ 65, varus angulation, and posterior dislocation were risk factors for increased extension of the fracture onto the articular surface. CONCLUSION: Intra-articular involvement in proximal humeral fractures is influenced by demographics and fracture characteristics (mechanism of injury, angulation, and dislocation). Patients with identified risk factors should be appropriately evaluated for intra-articular fractures during preoperative planning to assist in operative decision making. LEVEL OF EVIDENCE: Basic science; anatomy study.

Asymptomatic reference values for the Disability of Arm, Shoulder and Hand and Patient-Rated Wrist/Hand Evaluation - electronic data collection and its clinical implications.

The purpose of this study was to establish normal asymptomatic population values for the Disability of Arm, Shoulder and Hand and Patient-Rated Wrist/Hand Evaluation in healthy, asymptomatic individuals of different age, gender, ethnicity, handedness and nationality, using electronic data collection. Two-hundred and ninety-two Australian and 293 Canadian citizens with no active wrist pain, injury or pathology in their dominant hand, were evaluated. Participants completed an electronically administered questionnaire and were assessed clinically. There was no statistically significant association between both wrist scores and nationality. There was a statistically significant association between both wrist scores and age, demonstrating that as age increased, normal wrist function declined. This study has established an electronic, asymptomatic control group for future studies using these scores. When using the Disability of Arm, Shoulder and Hand and Patient-Rated Wrist/Hand Evaluation, the control group can be sourced from a pre-established control group within a database, without necessarily being sourced from the same country of origin. Level of evidence: II.

Fracture line morphology of complex proximal humeral fractures.

BACKGROUND: The aim of this study was to assess proximal humeral fracture patterns using 3-dimensional computed tomography images and relate them to the normal osseous landmarks and soft-tissue attachments. METHODS: Forty-eight 3-dimensional computed tomography scans of proximal humeral fractures were retrospectively collected, and the fractures were transcribed onto proximal humeral templates. We analyzed the common location and orientation of the fracture lines, with a focus on fractures of the articular surface, tuberosities, metaphysis, and proximal diaphysis. These fractures were compared with the attachments of the rotator cuff and glenohumeral capsule. RESULTS: Fifty-two percent of the fractures involved the articular surface. No fractures passed through the bicipital groove, and fractures were more commonly found on the posterior lesser tuberosity and on the anterior greater tuberosity, coinciding with the intervals between the rotator cuff tendon insertions. Intracapsular fractures of the calcar were more common (68%) than extracapsular fractures (32%). On the anterolateral aspect of the proximal humerus, fractures radiated from the articular margin, vertically down through the tuberosity zone between the rotator cuff footprints, meeting horizontally oriented fractures in the metaphyseal zone. On the posterior aspect, vertical fractures from the tuberosity zone continued downward to the metaphyseal zone adjacent to the infraspinatus and teres minor footprints. CONCLUSIONS: Fractures of the proximal humerus follow characteristic patterns. Fractures frequently split the greater tuberosity and are closely related to the intervals of the rotator cuff attachments.