Israel Medical Association Journal

Background: Trabecular bone score (TBS) reflects vertebrae microarchitecture and assists in fracture risk assessment. The International Society of Clinical Densitometry postulates that the role of TBS in monitoring antiresorptive therapy is unclear. Whether changes in TBS correlate with bone resorption measured by bone turnover markers is not known.

Objectives: To determine whether longitudinal changes in TBS correlate with C-terminal telopeptide (CTX) of type I collagen.

Methods: Examinees with two bone mineral density (BMD) measurements were detected via the institutional database. Over 5.8% change in TBS was considered least significant and patients were grouped accordingly (increment, decrement, or unchanged). CTX, BMD, co-morbidities, incident fractures, and medication exposure were compared between the groups by Kruskal-Wallis. The correlation between TBS and BMD change and CTX in a continuous model was analyzed by Pearson's correlation coefficient.

Results: In total, 110 patients had detailed medical records. In 74.5%, TBS change was below least significant change. Two other TBS categories, fracture incidence or medication exposure, did not differ by CTX. In the continuous model, BMD and TBS change was positively correlated (r = 0.225, P = 0.018). A negative correlation was observed between BMD change and CTX. The decrease in BMD level was associated with higher CTX (r = -0.335, P = 0.004). No correlation was observed between CTX and TBS.

Conclusions: No correlation between TBS dynamics and bone resorption marker was found. Clinical interpretation and implication of longitudinal TBS changes should be further explored.

Background: Evidence suggests that prolonged bisphosphonate (BP) treatment predisposes to atypical fractures (AF), but the etiology has yet to be determined. Addressing causality begins with case identification, which requires radiological adjudication. However, many trials based their case findings on coded diagnoses. 

Objectives: To investigate the feasibility of case findings by the coding system and the reproducibility of radiological evaluations in two hospitals in Israel, and to compare BP exposure of AF patients to a control group with typical (intertrochanteric of femoral neck) fractures. 

Methods: Diagnostic databases from 2007–2010 were reviewed and admission X-rays of patients were examined in two steps by two radiologists. Fractures were classified as atypical or not atypical according to published criteria. A 2:1 control group was created. Ambulatory drug acquisition was reviewed. 

Results: Of the 198 patients who fulfilled the search criteria, 38 were classified by initial radiological opinion as AF. Subsequent radiological opinion judged 16 as not atypical. Of the AF patients, 80% were exposed to BP. Of those, 81% continued to receive BP treatment for 2.4 years after AF. Only one AF patient was discharged with suspected AF diagnosis. In the control group, 27% were exposed to BP prior to fracture (P < 0.001). 

Conclusions: Thorough radiological revision is mandatory for proper classification of AF, and even when performed there is significant inconsistency in interpretation. Conclusions drawn from trials based solely on coded diagnoses lead to significant bias. BP exposure was significantly higher in the AF group. Caregiver unawareness of AF leads to improper management.