Poster 193: Glenoid Bone Loss Evaluation: Utilization of Current Methods

OBJECTIVES: Preoperative evaluation of glenoid bone loss is essential in surgical planning and for patients’ expectations of their surgical outcome. The four literature backed methods for measuring glenoid bone loss include the chord method, percent diameter method, the intraoperative probe method, and Pico method. Using the intraoperative probe method, it has been suggested that 25% bone loss of the inferior glenoid may be the threshold of significant bone loss. In contrast, other studies show bone loss using percent diameter above 13.5-17.3% has been associated with significantly worse clinical outcomes. Differences in bone loss measurements method utilization can lead orthopedic surgeons to proceeding with soft-tissue stabilization in a high-risk patient or alternatively to an unnecessary osseous augmentation procedure. Therefore, it is important to understand how orthopedic surgeons measure bone loss. While 3D CT and the Pico method have been previously described as the gold standard in bone loss evaluation for their highest accuracy and interobserver reliability, it is unclear how most orthopedic surgeons evaluate for bone loss in their practice. The purpose of this study is to investigate how orthopedic surgeons measure glenoid bone loss. METHODS: Based on existing literature, a 16-question survey was created by the senior author. This survey included questions investigating participants’ demographic information, typical surgical practice and volume, and glenoid bone loss identification method. The survey was sent out to members of the American Orthopedic Society for Sports Medicine (AOSSM) and Arthroscopy Association of North America (AANA). RESULTS: One-hundred-seventy-two orthopedic surgeons responded to the survey with an average of 13.4 years in practice and average number of instability surgeries performed each year of 31.2 +/- 35. In regard to subspecialty, 137 participants completed a sports medicine fellowship, 18 completed a shoulder and elbow fellowship, 10 completed both a sports medicine and shoulder and elbow fellowship, 1 completed a sports medicine and pediatric sports medicine fellowship, and 1 completed a sports medicine and trauma fellowship (97% response rate). Responders were from a variety of geographic locations: 26% were from the Northeast, 30% were from the Midwest, 21% were from the South, 10% were from Mountain States, 10% were from the West Coast, 1 was from Hawaii, 1 was from Alaska, 1 was from Columbia, and 1 practiced in Italy (98% response rate). 46% of responders belong to a private practice, while 34% practice at an academic institution. An additional 16% reported a hospital- based practice, 2% reported military affiliation, and 2% work in a private practice with academic affiliations (99% response rate). 91.3% of responders said that they routinely measure glenoid bone loss. 3D CT was the imaging modality most commonly used for bone loss evaluation (125), followed by 2D MRI (86), X-rays (68), 2D CT (60), and 3D MRI (11) (Figure 1). The frequency of four common bone loss evaluation methods were analyzed: percent diameter loss was the most commonly used and was used routinely, the intraoperative probe length method was used occasionally, Pico method was used rarely, and the chord length method was used never (Figure 2). There was no significant effect of time in practice, practice location, and fellowship training on bone loss methods. Those in private practice or a medical group setting had a higher frequency of using the intraoperative probe length method. CONCLUSIONS: The result of this study suggests that there is significant inconsistency in how orthopedic surgeons evaluate and measure glenoid bone loss in the setting of shoulder instability. While physicians commonly use the most reliable imaging modality (3D CT), the most accurate literature backed method for evaluating bone loss (Pico method) is seldom used. Future research is necessary to understand the limiting factor for orthopedic surgeons to incorporate validated glenoid bone loss measurements into their practice and develop new automated methods to improve overall utilization.