Management of dorso-lumbar pain secondary to anisotropic deterioration of vertebral trabecular architecture through clodronate treatment

BACKGROUND: Multiple mechanisms underlie the connection between osteoporosis and vertebral pain, beyond the established correlation from the occurrence of fragility fractures, both clinical and morphometric. Among these mechanisms are alterations in certain bone quality parameters, which result in the deterioration of vertebral trabecular architecture and have been correlated with the genesis of vertebral microfractures. Identifying these mechanisms necessitates a reinterpretation of spinal pain in osteoporotic patients without any evidence of fracture, often attributed to degenerative arthritic changes. This has important therapeutic implications, allowing for the possibility of effective pain treatments specific to the type of pain involved. Similarly to vertebral fractures, microfractures may also play a role in causing postural deviations and gait alterations through an antalgic mechanism, as detected by baropodometric examination. These, in turn, can contribute to the risk of falls and new vertebral fractures. Based on these premises, it was decided to combine these observations by evaluating the use of clodronate in the treatment of dorso-lumbar pain secondary to the deterioration of trabecular microarchitecture and in the prevention of trabecular microfractures. This was done using baropodometry as a tool for detecting vertebral pain and radiofrequency echographic multi spectrometry (REMS) technology for determining bone mineral density (BMD) and bone quality characteristics.METHODS: Thirty-six female patients with dorso-lumbar pain and densitometric T-scores between -2 and -2.5 were enrolled. All patients were prescribed clodronate 200 mg every 2 weeks, calcium carbonate 500 mg daily, and cholecalciferol 25,000 IU twice a month. All patients underwent REMS densitometry at T0 and T2 (8 months) and baropodometric examination at T0, T1 (4 months), and T2. The primary outcome was the number of patients achieving a 20% reduction in the WOMAC pain index (Western Ontario McMaster Universities Osteoarthritis Index), and the secondary outcome was the reduction in analgesic consumption in terms of days of use per month. Statistical significance of results was determined using Student’s t-test.RESULTS: All patients included in the study showed alterations in foot support in both static and dynamic conditions at baseline. At T2, there was a statistically significant reduction (P<0.001) in the average differences in these alterations compared to T0 and T1; all patients showed a significant reduction in the Womac pain score (P<0.03 vs. baseline) and average paracetamol consumption (P<0.02 vs. baseline). In REMS, there was a slight improvement in the average BMD value over the 8-month study period, while the average Fragility Score values (a dimensionless indicator independent of BMD and directly correlated with bone microarchitecture) at T0 remained constant at T2, showing slight improvement in some cases .CONCLUSIONS: The results of this study highlight the analgesic efficacy of clodronate, supporting the possibility that, in osteoporotic patients, even minimal structural alterations in vertebral trabecular bone, in the absence of clinical or morphometric fractures, can cause pain. This suggests reconsidering the often purely mechanical, arthritic genesis attribution of the pain. The analgesic action of clodronate may thus also be expressed through the improvement of bone quality aspects.