The effect of intraarticular anesthesia and elastic bandage on elbow proprioception.

Twenty uninjured male volunteers were studied to characterize normal elbow proprioception and to investigate the effect of applying an elastic bandage to the extremity and injection of an intraarticular anesthetic. A modified Biodex dynamometer was used to study position sense and detection of motion. In part 1 of the study position sense was tested by flexing the elbow to a predetermined angle, returning to the starting position, and then asking the subject to identify that angle. In part 2 detection of motion was tested by asking the subject to disengage the apparatus by pressing a stop button when movement was detected. The testing conditions in part 1 and part 2 were repeated after the elbow was wrapped with an elastic bandage and again after an intraarticular injection of 3 cc 1% lidocaine with the bandage removed. Ten additional subjects underwent testing of both elbows to examine the effect of arm dominance. Mean position sense was within 3.3 degrees+/-1.3 degrees of the actual angle in trials without an elastic bandage or an anesthetic. A significant improvement in position sense was observed (2.2 degrees+/-1.2 degrees) after an elastic bandage was applied (P < .004). No significant difference was seen in position sense after lidocaine was injected. The mean threshold for detection of motion in trials without an elastic bandage or an anesthetic was 4.21 degrees+/-1.56 degrees. No significant differences were seen in detection of motion observed with the elastic bandage or intraarticular anesthetic. No significant differences were seen between dominant and nondominant extremities for both position sense and detection of motion. The application of an elastic bandage improved position sense, suggesting that tactile cues from cutaneous or other extraarticular receptors may play a role in elbow proprioception. Intraarticular anesthesia, however, had little effect, suggesting that intracapsular receptors play a lesser role in elbow proprioception. The determination of proprioceptive qualities for the normal elbow can aid in the understanding of elbow function and provide a basis for defining its role in elbow dysfunction.

Examination of the lateral antebrachial cutaneous nerve: an anatomic study in human cadavers.

Variations in the anatomic course of the cutaneous nerves about the lateral aspect of the elbow are important when surgical exposures and the establishment of arthroscopic portals are considered. The specific anatomic course taken by the lateral antebrachial cutaneous nerve and its relationship to the lateral epicondyle were determined by studying 33 upper extremities in 22 preserved adult cadavers. Considerable anatomic variation was found regarding the location of the lateral antebrachial cutaneous nerve as it crossed the elbow. The nerve pierced the brachial fascia an average of 3.2 cm proximal to the lateral epicondyle and was located an average of 4.5 cm medial to the lateral epicondyle as it crossed the interepicondylar line. In two instances, the nerve passed through the biceps muscle directly, prior to piercing the brachial fascia.

The revascularization of healing flexor tendons in the digital sheath. A vascular injection study in dogs.

The role of revascularization in the nutritional support of repair of the flexor tendons is not completely understood. To explore the extent to which intrasynovial flexor tendons revascularize after transection and suture, a vascular injection study was carried out in a canine model. The tendons to the second and fifth digits of the forepaw in twelve adult mongrel dogs were transected and repaired. There were twenty-four experimental tendons and twenty-four normal tendons. The limb was placed in a polyurethane shoulder-spica cast, and the paw was treated with immediate protected passive mobilization. At three, seven, ten, seventeen, and twenty-eight days, the animals were killed and the major arteries supplying both the paw that had been operated on (left) and the contralateral normal paw (right) were injected with 200 milliliters of India ink. Segments of repaired and normal tendons were then clarified by a modified Spalteholz technique. The normal tendons demonstrated a well developed mesotenon that provided vascularization of the proximal portion of the flexor digitorum profundus tendon. A consistent three-cubic-millimeter avascular intrasynovial portion of tendon was noted. Distally, vessels arose from the vinculum breve, supplying the terminal twenty millimeters of tendon substance. In the experimental tendons, longitudinal and transverse clarified sections showed consistent revascularization of the site of repair by proximal vessels in the absence of ingrowth of peripheral adhesions. Vessels in the epitenon progressively extended for a distance of ten millimeters, through normally avascular regions, to reach the site of repair by the seventeenth postoperative day. Intratendinous vessels about the site of repair consistently originated from surface vessels, rather than from extensions of pre-existing intratendinous vessels. New vessels penetrated all areas, including the normally avascular volar segments of tendon, irrespective of previous topical zones of avascularity. Proximal vascular plexi were characterized by large tortuous vessels with frequent circuitous branches. More distal vessels had a longitudinally oriented, feathery appearance.