Development of a Classification System (OF-Classification) and a Score for Therapeutic Decision-Making (OF-Score) for Osteoporotic Thoracolumbar Fractures

Abstract

Introduction: The prevalence of osteoporotic fractures is continuously on the rise. The adequate treatment of the predominantly geriatric patients is quite challenging. Osteoporosis can either be the cause of thoracolumbar fractures (nontraumatic fracture) or act as a contributing factor in traumatic fractures. No commonly accepted classification for osteoporotic fractures currently exists. The goal of the “osteoporotic fracture” working group was to develop a classification system and a score to aid therapeutic decision-making process for patients with osteoporotic thoracolumbar fractures. Material and Methods: The development of both the classification and the score followed an established methodological pathway. Extensive literature research followed by in-depth discussions in nine consecutive sessions of expert meetings resulted in the proposed classification and scoring system. Between the sessions the classification and the score were applied by the group members in daily practice. The radiological and clinical data of 707 consecutive patients were subsequently collected in 16 clinics and evaluated. Interobserver reliability was calculated after evaluation of 146 fractures by 6 raters. Results: The OF-classification consists of five subgroups: OF 1—no deformation (edema in MRI STIR-sequence); OF 2—deformation without or with only minor involvement of the posterior wall ( 1/5); OF 4—loss of vertebral frame structure, vertebral body collapse, or pincer type fracture; OF 5—injuries with distraction or rotation. Interobserver reliability showed substantial agreement (Kappa 0.63). The OF-score contains the following parameters: fracture morphology (OF-classification), bone mineral density, potential sintering of the fracture, pain, neurological deficit, potential mobilization, and general health status of the patient (ASA grading), respectively. According to the OF-score, 29% of patients should have received conservative treatment and 49% surgical treatment, respectively. The final choice of treatment in the participating clinics correlated in 85% of cases with the OF-score. Conclusion: The OF-classification consists of five subgroups and shows substantial interobserver reliability. In comparison to other classifications, the OF-classification is easy to use and provides a superior differentiation of the typical osteoporotic fracture morphologies. The OF-score takes the clinical status of the predominantly geriatric patients into account to aid the decision-making process in adequate therapeutic strategies. The generated treatment recommendations reflect the actual treatment strategies of specialized clinical centers.