Clinical Outcomes Following Glenoid Neck Fracture as Correlated With Quantitative Assessment of Osseous Injury

Overview

A significant subset of patients with scapula fractures also involves the glenoid neck (bone joining the shoulder joint the scapular body). There is little evidence pertaining to the best treatment or precise definition of these lesions. This study will be designed as a prospective, non-randomized cohort study that will collect outcome and radiological data on patients who have sustained a fracture of the glenoid neck (bone joining the shoulder joint the scapular body) for a period of 1 year. All patients who have sustained extraarticular scapula fractures (any fracture not involving the glenoid surface) will be considered. Information will be collected with respect to the radiographic characteristics of osseous injuries as well as functional outcome over time.

Extraarticular fractures (fracture not involving the glenoid articular surface) of the scapula (shoulder blade) have been traditionally managed nonoperatively. The logic for this course of treatment was based on the healing potential of the extensive muscular envelop of the scapula, the inherent mobility of the shoulder joint, and the difficulty in objectively assessing the degree of injury given its irregular osseous architecture. Scapular fractures specifically involving the glenoid neck have the potential to significantly change the geometry of glenohumeral joint (shoulder joint) as well as affect the actions of muscles and nerves that act across it. Although most reports indicate patients sustaining glenoid neck fractures did well following nonoperative treatment, there was little use of validated outcome measures. Additionally, the context of severe trauma may have lead to an underestimation of functional recovery. Advances in imaging technology combined with the evolution of internal fixation techniques have resulted in sporadic attempts at fixation of glenoid neck fractures, usually when they occurred in concert with bony injury to other members of the shoulder girdle, as in the "floating shoulder". However, in the absence of a universal canon of radiograph measurements, there are no current recommendations for operative versus non-operative management based on the characteristics of osseous injury as correlated with probable clinical outcome. Moreover, the common assertion that nonoperative management of scapular fractures leads to adequate functional outcome has not been rigorously examined in a prospective fashion, despite this being the standard of care nationally. Recent evidence suggests that nonoperative treatment may lead to significant decreases in strength and forelimb function despite the fact that the standard of care for the vast majority of these injuries does not involve surgery or reduction. The same may be true of glenoid neck fractures, as significant shortening or angulation of this metaphyseal isthmus may have a detrimental effect on the functional geometry of the glenohumeral (shoulder) joint. If so, surgical management may be indicated to restore a more physiologic geometry to the joint, and thereby give the best chance of recovery to a pre-injury level of function. It is our hope that these correlates of measurements and outcome will help codify an a priori set of radiograph evaluation criteria to help guide decisions for surgical versus non-operative management of glenoid neck fractures. The purpose of the study is to: 1) define the degree of forelimb dysfunction brought about by this specific injury and 2) the magnitude of osseous injury to the glenoid neck that can be tolerated before functional outcome is unacceptably impeded.