Faculty Bibliography

The purpose of this study was to examine the possible relationship between delayed reaction time and slow coordination time as a contributing factor to lower extremity fracture. A simple reaction time tester and hand coordination tester were used to assess the relative times of reaction and coordination. Subjects were also questioned concerning their daily activity levels. A definite relationship was observed to exist between the times recorded and lower extremity fractures: subjects with lower extremity fractures exhibited delayed reaction times and longer coordination times. Moreover, shorter reaction times and coordination times were seen in those subjects who reported higher activity levels. Statistical analysis was performed on selected data which show an association of fracture with reaction time.

Two commercial adhesive preparations--fibrin glue and mussel adhesive protein (MAP)--were tested in-vivo for their ability to fix a chondrocyte allograft internally. While results for the fibrin, including additional testing for chondro inductive/conductive properties, were at best inconclusive, the results for MAP are highly promising

Using the knee joints of New Zealand White rabbits, a baseline study was made to determine the intrinsic capability of cartilage for healing defects that do not fracture the subchondral plate. A second experiment examined the effect of autologous chondrocytes grown in vitro on the healing rate of these defects. To determine whether any of the reconstituted cartilage resulted from the chondrocyte graft, a third experiment was conducted involving grafts with chondrocytes that had been labeled prior to grafting with a nuclear tracer. Results were evaluated using both qualitative and quantitative light microscopy. Macroscopic results from grafted specimens displayed a marked decrease in synovitis and other degenerative changes. In defects that had received transplants, a significant amount of cartilage was reconstituted (82%) compared to ungrafted controls (18%). Autoradiography on reconstituted cartilage showed that there were labeled cells incorporated into the repair matrix.

It is important to remember that knee disorders seen in the elderly are distinctly different from those seen in the younger individual. In the elderly, the problems are generally the result of chronic processes and, occasionally, an acute process on top of a chronic disorder. A careful history and physical examination should enable the physician in most cases to make the correct diagnosis. However, at times, specific laboratory studies may be ordered to confirm the diagnosis. In part I of this two-part review of geriatric knee disorders, the authors will focus on the anatomy, history, and physical examination of the knee joint. Common knee disorders specific to the elderly will be discussed in part II

This report describes the in-vitro use of mussel adhesive protein (MAP) as a possible adjunct to chondrocyte allograft surgery. Experiments were performed to define the attachment kinetics of chondrocyte onto bone using MAP, and to assess the biocompatibility of this material in vitro. The results indicate that MAP is biocompatible and may have future clinical applications in orthopaedic procedures.

With the increase in the use of shoulder arthroscopy in the past decade, there has been an increased awareness of complications. Reports of the occurrence of transient neuropraxia indicate an incidence of 10%-30%. The recording of somatosensory evoked potentials (SEP) for the study and functional monitoring of the sensory pathway is well accepted as a reproducible method of monitoring peripheral nerve and spinal cord function during surgery. SEPs were recorded during shoulder arthroscopy in 20 patients to monitor the musculocutaneous nerve, ulnar nerve, and either the median or radial nerve. In all 20 cases, abnormal SEPs of the musculocutaneous nerve were demonstrated. In 16 cases, this was produced upon initial joint distention, and in 15 cases, by traction; in 11, by longitudinal traction of greater than or equal to 12 lb, and in six by perpendicular traction of greater than or equal to 7 lb. In 10 patients, there were varying combinations of median, ulnar, and radial nerve involvement. There were two cases of clinical neuropraxia in this series. One resolved in 24 h and one in 48 h. The conclusion is that there is a real potential for neurologic damage during shoulder arthroscopy and that the musculocutaneous nerve is the most vulnerable. Factors responsible include joint distention, excessive traction, and extravasation of fluid. The use of SEPs provides a reliable means for monitoring the neurologic status of the extremity during shoulder arthroscopy.

Ligament insufficiency due to athletic injury is widely recognized and reported as an etiological factor in knee joint instability. It was recognized that a patient presenting with knee joint instability due to past hockey injury to the anterior cruciate ligament, subsequently verified surgically, was able to voluntarily and actively perform the pivot shift maneuver with his knee as a result of his anterolateral rotatory instability. During a subsequent 6 month period, three other patients with similar anterior cruciate deficiencies presented with this same active pivot shift maneuver phenomenon. A study was designed to determine the active muscle or muscles involved in this abnormal active motion in the knee joint with anterolateral rotatory instability. Electromyographic studies with needle electrodes were conducted on a variety of muscles in four subjects presenting with the instability. Results indicated that the popliteus muscle plays a major role in the active performance of the pivot shift maneuver.