Persistent disability associated with ankle sprains: a prospective examination of an athletic population.

The purpose of this study was to examine a young athletic population to update the data regarding epidemiology and disability associated with ankle injuries. At the United States Military Academy, all cadets presenting with ankle injuries during a 2-month period were included in this prospective observational study. The initial evaluation included an extensive questionnaire, physical examination, and radiographs. Ankle sprain treatment included a supervised rehabilitation program. Subjects were reevaluated at 6 weeks and 6 months with subjective assessment, physical examination, and functional testing. The mean age for all subjects was 20 years (range, 17-24 years). There were 104 ankle injuries accounting for 23% of all injuries seen. There were 96 sprains, 7 fractures, and 1 contusion. Of the 96 sprains, 4 were predominately medial injuries, 76 were lateral, and 16 were syndesmosis sprains. Ninety-five percent had returned to sports activities by 6 weeks; however, 55% of these subjects reported loss of function or presence of intermittent pain, and 23% had a decrement of >20% in the lateral hop test when compared with the uninjured side. At 6 months, all subjects had returned to full activity; however, 40% reported residual symptoms and 2.5% had a decrement of >20% on the lateral hop test. Neither previous injury nor ligament laxity was predictive of chronic symptomatology. Furthermore, chronic dysfunction could not be predicted by the grade of sprain (grade I vs. II). The factor most predictive of residual symptoms was a syndesmosis sprain, regardless of grade. Syndesmosis sprains were most prevalent in collision sports. This study demonstrates that even though our knowledge and understanding of ankle sprains and rehabilitation of these injuries have progressed in the last 20 years, chronic ankle dysfunction continues to be a prevalent problem. The early return to sports occurs after almost every ankle sprain; however, dysfunction persists in 40% of patients for as long as 6 months after injury. Syndesmosis sprains are more common than previously thought, and this confirms that syndesmosis sprains are associated with prolonged disability.

End range eccentric antagonist/concentric agonist strength ratios: a new perspective in shoulder strength assessment.

The dynamic muscle stabilizers of the shoulder are critical to high performance in the overhead athlete. Previous evaluations of shoulder strength have focused on the concentric strength of the rotator cuff. Functionally, the rotator cuff muscles interact in an eccentric/concentric fashion. This is the first study to evaluate the end range eccentric antagonist/concentric agonist ratios of the shoulder rotators. Seventy-five asymptomatic college-level males were tested through a range of 20 degrees of lateral rotation to 90 degrees of medial rotation using the Kin-Com computer-assisted, hydraulic-resisted, isokinetic dynamometer at a speed of 90 degrees/sec. The end range (60-90 degrees) ratios for the medial rotators functioning eccentrically and lateral rotators functioning concentrically were 2.39:1 and 2.15:1 for the dominant and nondominant shoulders, respectively. End range (10 degrees of lateral rotation-20 degrees of medial rotation) ratios for lateral rotators functioning eccentrically and medial rotators functioning concentrically were 1.08:1 and 1.05:1 for the dominant and nondominant shoulders, respectively. The application of this functional assessment of strength testing results may provide important information in the evaluation of the injured shoulder in the overhead athlete, for prescreening, and to gauge return to sports after injury or surgery.

The effect of tourniquet use in anterior cruciate ligament reconstruction. A prospective, randomized study.

To evaluate the effect of tourniquet use during anterior cruciate ligament reconstruction, 40 consecutive patients were randomized into two groups: Group I (tourniquet) and Group II (no tourniquet). Preoperative evaluation included electromyography, measurement of thigh and calf girth, and determination of serum creatinine phosphokinase levels. Initial postoperative evaluations included serial creatinine phosphokinase determinations. At 1 and 6 months postoperatively, the electromyographic examination was repeated and thigh and calf girth measurements were obtained. At 6 months and 1 year after surgery, the following evaluations were made: thigh and calf girth, KT-1000 arthrometric testing, isokinetic testing of quadriceps and hamstring muscles, single-legged hop test for time, single-legged hop test for distance, and the Lysholm knee score. In Group I, the tourniquet was inflated for an average of 87 minutes, with an average pressure of 269 mm Hg. At 1 month postoperatively, 6 of 20 patients in Group I had positive electromyographic recordings (compared with 2 of 20 in Group II, P = 0.08). At 1 month, thigh girths measured 10 cm proximal to the medial joint line suggested more atrophy in the tourniquet group (P = 0.07). At 6 months, all electromyographic recordings had returned to normal. At 6 months and 1 year postoperatively, girth measurements, isokinetic strength testing, functional testing, KT-1000 arthrometer evaluation, and the Lysholm knee scores were similar for both groups.

Single versus two-incision arthroscopic anterior cruciate ligament reconstruction.

The purpose of this study was to compare single (endoscopic) versus two-incision arthroscopic anterior cruciate ligament reconstruction using bone-patellar tendon-bone in a population of young athletes. All patients followed a similar postoperative rehabilitation program. The Lysholm knee score, the International Knee Documentation Committee Score, KT-1000 arthrometric measurements, Lachman tests, pivot shift tests, isokinetic and functional testing, and perioperative complications were used to compare the two techniques. Anteroposterior and lateral radiographs were also evaluated and compared. Group I comprised 51 patients who underwent two-incision arthroscopic ACL reconstruction. The average age was 19.8 years, with a range of 18 to 22. The average follow-up in this group was 31 months (range, 24 to 43 months). Group II, the endoscopic group, consisted of 31 patients with an average age of 19.4 years (range, 18 to 22). The average follow-up was 25 months (range, 24 to 31 months). There were no significant differences between the two groups using subjective, objective, and functional criteria. There did appear to be a trend toward a residual pivot glide in the endoscopic group, but this did not achieve statistical significance. Radiographic analysis demonstrated an increased incidence of screw divergence in the endoscopic group. Intraoperative complications were more common with the endoscopic method.

Ultrasound's effect on the conduction latency of the superficial radial nerve in man.

Research has clearly demonstrated that ultrasound has an effect on nervous tissue and its ability to propagate an action potential, but controversy exists concerning what physiological changes occur and whether these changes are due to the thermal or mechanical properties of ultrasound. The purpose of this study was to clarify the effect caused by mechanical and heating factors on sensory nerve conduction by comparing the effects of equivalent temperature changes by a strictly thermal source and by ultrasound. Ten healthy adults were exposed to ultrasound and infrared on separate treatment sessions to create a 1.2 degrees C increase in subcutaneous tissue temperature. Nerve conduction latencies were recorded for each 0.3 degrees C increase during both the ultrasound and infrared treatments. Results were analyzed using a two-way analysis of variance and a matched-group Student's t test. The combined mechanical and heating effects of ultrasound caused a decrease in latency of the lateral cutaneous branch of the radial nerve, similar to that of the heating effects of infrared. The results indicated that ultrasound's mechanical effects did not play a significant role in affecting the nerve conduction latency.