Bone mineral density, pain and overall disability of the upper limb in women with trapeziometacarpal osteoarthritis

Introduction The impairment of the trapeziometacarpal (TMC) joint reduced up to 50 % the functional capacity of the whole upper limb, since this joint plays a key role in the execution of almost all activities requiring grasping and handling. Although TMC osteoarthritis and osteoporosis are highly prevalent in post-menopausal women, the relationship between these conditions is poorly understood. The primary endpoint of this study was to evaluate the bone mineral density (BMD) at the distal one third of the radius in women with trapeziometacarpal osteoarthritis. The secondary outcomes were to evaluate the effect of TMC osteoarthritis on handgrip strength, pain and overall function of the upper limb. Methods In this cross-sectional study carried out in Physical Medicine and Rehabilitation Outpatient Clinic, we included all patients with TMC osteoarthritis. Men and women under 50 years, subjects with other hand and wrist disorders were excluded from evaluation. All subjects were assessed with a comprehensive approach including measurement of handgrip strength, pain and hand disability, using the Brief Pain Inventory (BPI) and the Quick DASH scale (Disabilities of the Arm, Shoulder and Hand), and BMD at the distal one third of the radius, measured using dual energy X-ray absorptiometry (DXA). Results In our population (39 women), the mean age was 69 years, the mean body mass index (BMI) was 27.7 kg/m2. Our sample was divided into 2 groups, according to Eaton-Glickel classification: the first group (20 women, Eaton-Glickel stages 1 to 2) showed mean values of BMD higher than the mean BMD of patients in the second group (19 women, Eaton-Glickel stages 3 to 4) (0.722 vs. 0.603 g/ cm2, p\0.01). The handgrip strength was reduced in both groups (11.5 kg in the first group and 8.6 kg in the second one), with a nonsignificant difference. Algo-functional assessment showed no significant difference between the 2 groups. Discussion In our population the BMD at the distal 1/3 of the radius is significantly reduced in subjects with severe TMC osteoarthritis. Conversely, the stage of articular surface involvement was not associated with handgrip strength, BPI indices and Quick-DASH score. Conclusions The presence of TMC osteoarthritis could be impacting the forearm bone mass and overall functionality of the upper limb, even if It seems there is no close correlation between the level of severity of osteoarthritis and functional limitation.