Physiological bone responses in the fingers after more than 10 years of high-level sport climbing: analysis of cortical parameters.

ABSTRACT

OBJECTIVE: Sports activity can induce bone modeling processes with apposition of new bone and changes in bone morphology. Sport climbing places extreme forces and stress on the hands, especially on the bones of the fingers. This study examines sports-induced physiological adaptations of the finger bones of climbers. METHODS: In this cohort study, the radiographs of 31 high-level (Union Internationale des Associations d'Alpinisme [UIAA] metric scale range 8.33 to 11.33), experienced (median 20 years climbing time) adult climbers were compared with those of a control group of 67 patients. Cortical dimensions and variables were measured and analyzed in a total of 330 fingers. An association analysis of climbing-related variables was also performed. RESULTS: The climber's bones showed a 25% higher cortical proportion than those of the control group. On average, the outer cortical width of the climbers' bones was 6% larger and the medullary canal was 20% narrower than in the control group (P < .05). The differences between groups were more pronounced in the sagittal plane and more pronounced distally in the fingers. No associations were found between age, climbing experience, climbing level, and the cortical hypertrophy. CONCLUSIONS: Differences in bone morphology can be observed in the finger bones of adult climbers when compared with controls. Because the differences are more pronounced at the palmar and dorsal cortices, the analysis of the sagittal plane should always be included in future investigations. To evaluate climbing-related factors influencing these adaptive morphologic differences, further studies with larger, more specific study cohorts are needed.