Effectiveness of radiographs and computed tomography in evaluating primary elbow osteoarthritis.

BACKGROUND: Preoperative radiographic assessment of osteophyte and loose body locations is critical in planning an arthroscopic débridement for primary elbow osteoarthritis. The purpose of this study was to evaluate the effectiveness of radiographs and computed tomography (CT) in localizing osteophytes and loose bodies. METHODS: A consecutive series of 36 patients with primary elbow osteoarthritis was investigated with radiographs and multiaxial 2-dimensional CT prior to elbow arthroscopy. The location of osteophytes and loose bodies was assessed in 9 anatomic locations by 2 fellowship-trained upper extremity surgeons. The diagnostic effectiveness of both imaging modalities was evaluated by calculating the sensitivity and specificity and compared to the gold standard of elbow arthroscopy. Inter- and intrarater percentage agreement between the observations was calculated using Kappa score. RESULTS: The mean sensitivity for detecting osteophytes in the 9 different anatomic locations was 46% with radiographs and 98% with CT, whereas the mean specificity was 66% and 21% for radiographs and CT, respectively. The mean sensitivity and specificity for loose body detection with radiography were 49% and 89%, respectively, whereas CT had a mean sensitivity of 98% and specificity of 47%. The overall inter-rater percentage agreement between the surgeons in detecting osteophytes and loose bodies on radiographs was 80% and 85%, respectively, whereas on CT it was 95% for detecting osteophytes and 91% for loose bodies. CONCLUSION: CT has greater sensitivity than radiographs for the detection of osteophytes and loose bodies in primary elbow osteoarthritis. The lower specificity of CT may be due to this imaging modality's ability to detect small osteophytes and loose bodies that may not be readily identified during elbow arthroscopy. Radiographs have an inferior inter-rater percentage agreement compared with CT. CT is a valuable preoperative investigation to assist surgeons in identifying the location of osteophytes and loose bodies in patients undergoing surgery for primary elbow osteoarthritis.

Loading at the distal radius and ulna during active simulated dart throw motion.

Loading at the distal forearm during dart throw motion (DTM) has been examined under static loads but there is no consensus on how loading is affected by active motion. In this work two implants were designed to measure forearm loading in a cadaveric model of wrist motion. Loads through the radius and ulna were significantly greater in reverse DTM than forward DTM. Radius loads were greatest in extended and radial deviated positions, and ulnar loads were greatest in flexed and ulnar deviated position. This work gives insight into the biomechanics of loading of the forearm to guide further studies.