J Bone Miner Metab (2001) 19:317–320 © Springer-Verlag 2001 Carpal tunnel syndrome leads to significant bone loss in metacarpal bones Taner Erselcan 1 , Kamil Topalkara 2 , Vedat Nacitarhan 3 , Aytekin Akyuz 2 , and Derya Dogan 1 1 Department of Nuclear Medicine, Cumhuriyet University School of Medicine, P.K. 806, Sivas, Turkey 2 Department of Neurology, Cumhuriyet University School of Medicine, Sivas, Turkey 3 Department of Physical Therapy and Rehabilitation, Cumhuriyet University School of Medicine, Sivas, Turkey also lead to bone mass loss in an individual extremity [2–4]. Extensive research efforts have been devoted to bone density studies in osteoporosis because it is now well understood that low bone mass is a predictor of future fractures. The determination of the fracture risk, so as to reduce health care costs and morbidity, is the first step. However, the best assessment of fracture risk at a specific site is made by measuring bone mass at that site [5]. Because muscle (thenar) atrophy is present in advanced cases of CTS, it is questionable whether there is any associated bone loss that may, ultimately, lead to a fragility fracture. It has been reported in one study that, according to radiometric findings, metacarpal bone density was increased in patients with CTS following a ligament-releasing operation [6]. However, neither quantitative bone nor fracture risk assessments have been performed in CTS patients since then. If the re- lease of disease gives rise to an increase in bone density in an affected extremity, then bone loss would, hypo- thetically, be an expected consequence of CTS, espe- cially in chronic cases. Thus, the aim of the present study was to investigate forearm and metacarpal bone mineral density (BMD) modifications in CTS. Materials and Methods Patients Over 2 years, 50 consecutive patients (four men, 46 women) with clinically and electrophysiologically diag- nosed CTS were enrolled in the study. Of those, four men and 13 postmenopausal women were excluded from the study to allow for a homogeneous study group for BMD comparisons. The remaining patients con- sisted of 18 unilaterally and 15 bilaterally affected pre- menopausal women. Of the 66 extremities, 18 were not affected by CTS and 48 were. Affected extremities were Abstract The present study was designed to determine bone density modifications at the forearm and metacarpal bones in patients with carpal tunnel syndrome (CTS). Bone mineral density (BMD) was measured by dual-energy X-ray absor- ptiometry at the one-third distal end and for the total of the radius–ulna, together with the third and fourth metacarpal bones, in 48 clinically and electrophysiologically diagnosed (18 unilateral and 15 bilateral) affected extremities in 33 pre- menopausal women (mean age 38.9  6.5 years) with CTS. BMD values for non-affected extremities were used as con- trols for comparison with affected extremities. Bone mass was decreased approximately 7% in the forearm region (P  0.02) and 18% in metacarpal bones (P  0.01) of the thenar atrophy associated group compared with controls. A significant corre- lation was observed between disease duration (mean duration 3.2  2.7 years) and the decrease in metacarpal bone density (r = 0.43; P = 0.004). This is the first clinical report of quantified bone loss in affected extremities in patients with CTS, and the results suggest the need for further studies to assess the clinical significance and morbidity of this pathology, especially in patients with thenar atrophy. Key words carpal tunnel syndrome · DEXA · bone density · thenar atrophy · metacarpal bones Introduction Carpal tunnel syndrome (CTS) is a consequence of chronic median nerve compression at the wrist. The syndrome is common, with an estimated population life- time cumulative incidence rate of 8%, and it can be associated with substantial disability [1]. The nerve de- generation and muscle weakness leads to thenar atro- phy as the disease advances. The muscle atrophy may Offprint requests to: T. Erselcan Received: November 1, 2000 / Accepted: February 28, 2001