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This study evaluates the role of magnetic resonance imaging in assessing the factors affecting the rate and healing time in scaphoid nonunions after surgery. Nineteen patients were assessed before surgery by radiographs, tomography, and magnetic resonance imaging. Fifteen bad viable bone marrow and 4 patients had nonviable bone marrow on magnetic resonance imaging. All patients with normal preoperative magnetic resonance imaging healed in an average time of 4.7 months. Of the 4 patients with abnormal magnetic resonance imaging, but normal plain radiographs, 2 went on to heal in 10.5 months. The remaining 2 patients with abnormal magnetic resonance imaging and abnormal plain radiographs did not heal by 24 months. This study suggests 3 groups of scaphoid nonunions. Group 1 has normal trabecular bone radiographically and

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A computerized hand and wrist motion analysis system was modified to capture data at a rate of up to 1000 Hz. Using this system, wrist flexion and extension data were collected on five right-handed professional pitchers (75 pitches). A wrist position versus time graph was generated for each pitch. The pitch data produced a reproducible analysis of motion for the majority of the pitches regardless of pitcher. Based on the graphic display of data points, four phases of wrist motion during a pitch were identified. The first phase is the cocking phase, or the motion of the wrist as it moves into maximum extension. This is then followed by the most explosive phase, the acceleration phase, which represents ball propulsion. At ball release, the wrist progresses through flexion and there is a consistent decrease in wrist velocity, known as the deceleration phase. Finally, there is the recovery phase, or the return of the wrist toward neutral. Average values for wrist range of motion, length of phase, and angular velocity (degrees per second) were calculated for each phase of the pitch. This study represents a major step toward quantifying motion of the wrist during a pitch. The ability to quantify this motion may prove valuable in the assessment of throwing athletes after injury and rehabilitation.

Several devices have been developed for rapid motor or sensory median nerve conduction testing. We evaluated the validity and reliability of the Neurosentinel (NS) and NervePace (NP) electroneurometer for sensory and motor testing, respectively, compared with formal electrodiagnostic studies (EDS), and examined their potential role in workplace screening for carpal tunnel syndrome (CTS). Thirty-two working subjects without CTS were examined and tested with the NS, NP, and EDS, and retested one week later. Subjects were selected who did not have CTS, other hand or nerve problems, or jobs with significant ergonomic risks, in order to decrease the likelihood of changes over time in median nerve function. Mean correlations of NP and NS with EDS latencies ranged from r = 0.069 to r = 0.85, with somewhat better correlation for NS (sensory) than NP (motor). Test-retest reliability was greatest for motor EDS (r = 0.86 to 0.91) and similar for sensory EDS, NS, and NP (r = 0.72 to 0.79); mean results were very similar. Based on the observed relationship between NS or NP and EDS results, confidence intervals were calculated to represent the range of EDS results consistent with a single NS or NP measurement. These intervals ranged from +/- 0.3 milliseconds (ms) for NS to +/- 0.6 msec for NP, with similar ranges for change over time in an individual. The magnitude of these intervals for a single test or individual implies that the NS and NP are unlikely to identify individuals with CTS or to detect changes over time that are not accompanied by symptoms or signs. The screening devices are not likely to be useful in confirming early CTS, when single latency values may be normal, and detailed EDS may be necessary to detect nerve entrapment. Compared with EDS, these devices have moderate validity and similar reliability; they are probably most useful for cross-sectional or longitudinal studies of groups, but care must be taken in using them for pre-placement or surveillance tests of individual workers. False-positive results may lead to discrimination, inappropriate referrals and interventions; false-negative tests can result in inappropriate reassurance and missed opportunities for intervention.