Qualitative Evaluation of Digital Hand Xrays is Not a Reliable Method to Assess Bone Mineral Density

The gold standard for evaluating bone mineral density is dual energy xray absorptiometry (DEXA).  Prior studies have shown poor reliability using analog wrist Xrays in diagnosing osteoporosis. Our goal was to investigate if there was improved diagnostic value to visual assessment of digital hand Xrays in osteoporosis screening. We hypothesized that similar to analog counterparts, digital hand Xrays have poor correlation and reliability in determining bone mineral density (BMD) relative to DEXA.Methods: We prospectively evaluated female patients older than 65 years who presented to our hand clinic with digital hand and wrist Xrays as part of their evaluation over six months. Patients who had a fracture and were without DEXA scans within the past two years were excluded. Five fellowshiptrained hand surgeons, blinded to DEXA Tscores, evaluated the xrays over two assessments separated by four weeks and classified them as osteoporotic, osteopenic, or normal BMD.  Accuracy relative to DEXA Tscore, interobserver and intraobserver rates were calculated.Results: Thirty four patients met the inclusion criteria and a total of 340 xrays reviews were performed.  The assessments were correct in 169 cases (49%) as compared to the DEXA Tscores. A mean weighted kappa coefficient of agreement between observers was 0.29 (range 0.020.41) reflecting a fair agreement. The first and second assessment for all five physicians was 0.46 (range 0.190.78) reflecting a moderate agreement.  Grouping osteoporosis and osteopenia together compared to normal, the accuracy, interobserver and intraobserver rates increased to 63%, 0.42 and 0.54 respectively.Conclusion: Abnormally low BMD is a common occurrence in patients treated for upper extremity disorders. There is poor accuracy relative to DEXA scan and only fair agreement in diagnosing osteoporosis using visual assessments of digital x-rays.