The American Journal of Sports Medicine

In a sports medicine center, we prospectively evaluated the Ottawa Ankle Rules over 1 year for their ability to identify clinically significant ankle and midfoot fractures and to reduce the need for radiography. We also developed a modification to improve specificity for malleolar fracture identification. Patients with acute ankle injuries ( 10 days old) had the rules applied and then had radiographs taken. Sensitivity, specificity, and the potential reduction in the use of radiography were calculated for the Ottawa Ankle Rules in 132 patients and for the new “Buffalo” rule in 78 of these patients. There were 11 clinically significant fractures (fracture rate, 8.3% per year). In these 132 patients, the Ottawa Ankle Rules would have reduced the need for radiography by 34%, without any fractures being missed (sensitivity 100%, specificity 37%). In 78 patients, the specificity for malleolar fracture for the new rule was significantly greater than that of the Ottawa Ankle Rules malleolar rule (59% versus 42%), sensitivity remained 100%, and the potential reduction in the need for radiography (54%) was significantly greater. The Ottawa Ankle Rules could significantly reduce the need for radiography in patients with acute ankle and midfoot injuries in this setting without missing clinically significant fractures. The Buffalo modification could improve specificity for malleolar fractures without sacrificing sensitivity and could significantly reduce the need for radiography.

Previous experimental studies have indicated delayed muscle regeneration after nonsteroidal antiinflammatory drug therapy. Successful regeneration of muscle after injury requires activation of normally dormant satellite cells that share the basal laminae with adjacent muscle cells. In the presence of adequate capillary ingrowth, satellite cells proliferate into myotubes and eventually form new muscle cells. In this study, the onset and extent of satellite cell and fibroblast proliferation as well as the production of myotubes and capillaries were analyzed with immunohistochemical methods after contusion injuries to rats' gastrocnemius muscles. Two groups of animals received daily doses of an intramuscular nonsteroidal antiinflammatory drug (naproxen) starting 6 hours and 3 days after injury, respectively. Treated animals were compared with similarly injured untreated animals. Satellite cell and fibroblast proliferation were unaffected by the treatment, and there were no significant differences in myotube or capillary production between treated and control animals. We conclude that naproxen treatment does not compromise the basic process of myofiber regeneration after injury.

A retrospective study of cervical spine injuries that occurred during the rugby scrum in the United States was undertaken. In the U.S., from 1970 to 1996, 36 (58%) of the 62 documented injured players injured their cervical spines during the scrum. Thirty-five men (97%) and one woman (3%) were injured. Twenty-three of the injuries (64%) occurred when the opposing packs came together (engagement), and 13 (36%) occurred when the scrum collapsed. Twenty-eight (78%) hookers, seven (19%) props, and one (3%) second-row player were injured. Twenty (56%) hookers and three (8%) props were hurt during engagement. Eight hookers (22%), four props (11%), and one second-row player (3%) were injured when the scrum collapsed. Significantly more injuries occurred during engagement than during collapse, and hookers were injured significantly more than props. We conclude that in the rugby scrum in the U.S., the hooker suffers most of the cervical spine injuries (78% in this study) and this position is by far the most vulnerable. This study should be used to develop rugby law (rule) changes and educate players, coaches, and referees in United States rugby.

We performed a retrospective study on 80 patients who underwent single-incision arthroscopic anterior cruciate ligament reconstruction with patellar tendon autograft and interference fit screw fixation in 1989. Twelve patients were lost to followup, allowing a clinical assessment of 68 patients to be conducted by independent examiners at 1 and 5 years after surgery, with radiographic assessment at 5 years. Thirty-three patients had chronic anterior cruciate ligament-deficient knees. Three patients reruptured their grafts during sports at 29, 48, and 56 months. At 5 years, 64 patients (98%) had grade 0 or 1 Lachman and pivot shift tests with manual stability testing. Fifty patients (77%) were participating in level I or II activities according to the International Knee Documentation Committee scale. Twenty-nine patients (45%) experienced low levels of pain when performing at their highest activity level. Five (8%) had thigh atrophy greater than 1 cm, and three (5%) had an extension loss of more than 3°. Eleven patients (17%) had tenderness over the graft site when kneeling. Fifteen of 62 patients (24%) had degenerative changes on radiographs, and this was more common in patients with chronic anterior cruciate ligament-deficient knees. Fifty-two patients (80%) had normal or nearly normal knees according to the overall International Knee Documentation Committee score.

Ten consecutive patients with isolated atraumatic osteolysis of the distal clavicle who had failed results with conservative treatment were treated with arthroscopic resection of the involved distal clavicle (average, 4.5 mm). All patients were men with an average age of 30.4 years, had unilateral involvement, and were considered aggressive amateur to elite weight lifters or bodybuilders. Postoperative symptoms consisted of pain at the incision and discomfort from extravasation of the irrigation fluid. At an average followup of 18.7 months, all patients had returned to their sport (average, 3.2 days) and to their preoperative weight training program (average, 9.1 days). They continued to be asymptomatic throughout the follow-up period and were able to increase both their training volume and strength from preoperative levels. Limited arthroscopic resection of the distal clavicle for isolated atraumatic osteolysis is a viable alternative for the weight lifter or bodybuilder. The ability to continue training without significant interruption as well as a more acceptable cosmetic appearance are benefits for these patients. Limited arthroscopic resection of the distal clavicle may be sufficient for this entity in this patient population, rather than the 1 to 2 cm previously reported. A sport-specific functional outcome questionnaire has been developed for this patient population.

We assessed the possible association between an aggressive intercondylar notchplasty and histopathologic, radiographic, and gait changes to the knee. Three groups of six adult greyhounds were observed for 6 months. Group I dogs had a sham operation. Group II dogs had a 4-mm notchplasty of the lateral femoral condyle where it articulates with the lateral tibial spine. Group III dogs had a 7- to 8-mm notchplasty of the lateral femoral condyle to simulate the long-term effects of an overly aggressive notchplasty. Force plate gait analyses were not significantly different for any dogs at 3 and 6 months. Histopathologic studies (hematoxylin and eosin and safranin O stains) revealed notchplasty area remodeling with a thin layer of lamellar bone covered by fibrous connective tissue. Both Group II and III dogs had significant loss of lateral femoral condyle and trochlear groove articular surface proteoglycans. The radiographic notch width index remained unchanged throughout the study for Group I; the indexes increased immediately after surgery in Groups II and III because of the notchplasty, but after 6 months these values returned to near-preoperative measurements. An aggressive intercondylar notchplasty caused articular cartilage histopathologic changes at 6 months consistent with those found in knees with early degenerative arthritis. Significant refilling of a non-impinged notchplasty occurred by 6 months after surgery. Our results raise concern about the effects of aggressive intercondylar notch widening in humans.

Patellofemoral pain may be associated with anterior cruciate ligament deficiency or may occur after anterior cruciate ligament reconstruction. We investigated the effects of the removal and reconstruction of the anterior cruciate ligament on the kinematics of the tibiofemoral and patellofemoral joints during physiologic levels of quadriceps muscle loads in seven cadaveric knees. A bone-patellar tendon-bone graft was used for intraarticular reconstruction of the anterior cruciate ligament. The spatial positions of the tibiofemoral and patellofemoral joints were measured between 0° and 90° of knee flexion in 15° increments with a six degree-of-freedom digitizing system. Excision of the anterior cruciate ligament resulted in statistically significant increases in anterior tibial translation between 0° and 90° and valgus tibial rotation between 30° and 90°; intraarticular reconstruction returned these to levels not significantly different from those of the intact knee. Excision of the anterior cruciate ligament resulted in significant increases in lateral patellar tilt, ranging from 6.3° to 9.0° between full extension and 90° of knee flexion, and in lateral patellar shift, ranging from 2.9 mm at 15° of knee flexion to 5.9 mm at 90°; intraarticular reconstruction returned these to levels not significantly different from those of the intact knee. Neither removal nor reconstruction of the anterior cruciate ligament significantly affected tibial internal-external rotation, patellar flexion, patellar mediolateral rotation, patellar anteroposterior translation, or patellar proximodistal translation.

Muscle activity (measured by electromyography) and applied load were measured during seven shoulder rehabilitation exercises done with an elastic resistance device. Nineteen men with no shoulder abnormalities performed seven exercises: external and internal rotation, forward punch, shoulder shrug, and seated rowing with a narrow, middle, and wide grip. Qualitative video (60 Hz) was synchronized with the electromyography data from eight muscles (2000 Hz). Fine-wire intramuscular electrodes were inserted into the supraspinatus and subscapularis muscles, and surface electrodes were placed over the anterior deltoid, infraspinatus, pectoralis major, latissimus dorsi, serratus anterior, and trapezius muscles. Ten trials per subject were analyzed for average and peak amplitude, and the results were expressed as a percentage of maximum voluntary contractions. The peak loads for all exercises ranged from 21 to 54 N. The muscle activity patterns suggest that these shoulder rehabilitation exercises incorporating elastic resistance, controlled movements, and low initial loading effectively target the rotator cuff and supporting musculature and are appropriate for postinjury and postoperative patients.

To examine the importance of resistance training movement speed, two groups of women (24 4 years, 162 5 cm, 59 7 kg) squatted repeatedly at 1) 2 seconds up, 2 seconds down (slow, N 11); or 2) 1 second up, 1 second down (fast, N 10), doing three warm-up sets and three eight-repetition maximum sets, three times per week for 7 weeks. Tests included force platform and video analysis of the vertical jump, long jump, and maximum squat, and isometric and isokinetic knee extensor testing at speeds from 25 to 125 deg/sec. The groups improved similarly in many variables with training but also showed some differences. In the long jump, the fast group was superior in numerous variables including knee peak velocity and total-body vertical and absolute power. In the vertical jump, fast training affected the ankle and hip more (e.g., average power), and slow training mostly affected the knee (average torque). In isokinetic testing, the fast group improved strength most at the faster velocities, while the slow group strength changes were consistent across the velocities tested. Although both slow and fast training improved performance, faster training showed some advantages in quantity and magnitude of training effects.

Conventionally, the hamstring:quadriceps strength ratio is calculated by dividing the maximal knee flexor (hamstring) moment by the maximal knee extensor (quadriceps) moment measured at identical angular velocity and contraction mode. The agonist-antagonist strength relationship for knee extension and flexion may, however, be better described by the more functional ratios of eccentric hamstring to concentric quadriceps moments (extension), and concentric hamstring to eccentric quadriceps moments (flexion). We compared functional and conventional isokinetic hamstring: quadriceps strength ratios and examined their relation to knee joint angle and joint angular velocity. Peak and angle-specific (50°, 40°, and 30° of knee flexion) moments were determined during maximal concentric and eccentric muscle contractions (10° to 90° of motion; 30 and 240 deg/sec). Across movement speeds and contraction modes the functional ratios for different moments varied between 0.3 and 1.0 (peak and 50°), 0.4 and 1.1 (40°), and 0.4 and 1.4 (30°). In contrast, conventional hamstring:quadriceps ratios were 0.5 to 0.6 based on peak and 50° moments, 0.6 to 0.7 based on 40° moment, and 0.6 to 0.8 based on 30° moment. The functional hamstring:quadriceps ratio for fast knee extension yielded a 1:1 relationship, which increased with extended knee joint position, indicating a significant capacity of the hamstring muscles to provide dynamic knee joint stability in these conditions. The evaluation of knee joint function by use of isokinetic dynamometry should comprise data on functional and conventional hamstring:quadriceps ratios as well as data on absolute muscle strength.

A unique aspect of soccer is the use of the head for directing the ball. The potential for resultant head injuries has been the focus of discussions worldwide. Prior work has attributed neuropsychologic deficits to the cumulative effects of heading, without evaluating concussion rates in soccer players. We prospectively studied the seven men's and eight women's varsity soccer teams in the Atlantic Coast Conference during two seasons to document concussion incidence. The 29 concussions diagnosed over the 2 years in 26 athletes, 17 (59%) concussions in men and 12 (41%) in women, resulted from contact with an opponent's head (8, 28%), elbow (4, 14%), knee (1, 3%), or foot (1, 3%); the ball (7, 24%); the ground (3, 10%); concrete sidelines (1, 3%); goalpost (1, 3%); or a combination of objects (3, 10%). Twenty concussions (69%) occurred in games; none resulted from intentional heading of the ball. The basic incidence was 0.96 concussions per team per season. The overall incidence was 0.6 per 1000 athlete-exposures for men, and 0.4 per 1000 athlete-exposures for women. By concussion grade, there were 21 (72%) grade 1, 8 (28%) grade 2, and no grade 3 concussions. These findings suggest that concussions are more common in soccer than anticipated and that acute head injuries may have potential for long-term neuropsychologic changes.

Ninety patients with humeral shaft fractures sustained during throwing were analyzed to determine what caused their injuries. All patients were recreational baseball players: 89 were men and 1 was a woman. The average age was 25 years (range, 12 to 43). The throwing style, type of pitch, fielding position, and type of ball used varied; however, the patients sustained their fractures while performing a hard throw in 87 (97%) of the occurrences. The actual courses of the balls thrown ranged from sideways to straight forward. All fractures were external rotation spiral fractures; 25 patients (28%) had a medial butterfly fragment, and 14 patients (16%) had radial nerve palsy. Fractures were most likely to have occurred in the distal half of the humerus, although they occurred frequently in the proximal half in patients in their early teens. We conclude that 1) the fracture can occur at any time during the acceleration phase before ball release, 2) this type of fracture can occur in any recreational baseball player attempting to perform a hard throw, and 3) the cause of this fracture is the throwing action itself.

Sport-specific upper extremity strain, mostly unilateral, during growth may lead to adaptations in soft tissue and bone. We investigated 51 male professional handball players between 18 and 39 years of age (average, 27 years), 39 right-handed and 12 left-handed. Thirty-eight players had no shoulder problems, and 13 had chronic shoulder pain. Humeral retrotorsion was determined by radiograph. The differences between the throwing and contralateral arms were compared with those of 37 controls who had no history of unilateral strain either through sports or profession. Standard statistical analysis was performed using the t-test. The retrotorsional angle of the humerus in the handball professionals' throwing arm was an average of 9.4° larger in the dominant side than in the nondominant, with a side-to-side difference up to 29°. In the control group, no statistically significant difference was found. In the group without chronic shoulder pain, the side-to-side difference was an average of 14.4° more in the throwing arm than the other side. Players with chronic shoulder pain did not exhibit this increase, even showing an average decrease of humeral retrotorsion of 5.2° in the throwing arm. The humeral retrotorsion increase can be explained as an adaptation to extensive external rotation in throwing practice during growth. Athletes who do not adapt this way seem to have more strain on their anterior capsules at less external rotation and develop chronic shoulder pain because of anterior instability.

The purpose of this study was to evaluate the clinical, functional, and radiographic outcomes of the conventional and modified Boyd-Anderson procedures for repair of distal biceps tendon ruptures. Thirteen of 18 men who underwent surgical repair for unilateral distal biceps tendon ruptures at one university center participated in the study. In general, follow-up outcomes were favorable with respect to return to premorbid activity levels, patient satisfaction with surgical outcome, and overall clinical results. Elbow flexion, forearm supination, and upper extremity functional concentric peak torque and range of motion results were not significantly different between the surgical and nonsurgical arms when dominance was controlled as a confounding factor. Radiographic findings revealed no clinically remarkable signs of heterotopic ossification or proximal radioulnar synostosis. Results of the study reveal that the conventional and modified Boyd-Anderson procedures are clinically, functionally, and radio-graphically efficacious for repair of distal biceps tendon ruptures.

Proprioception, or joint position sense, probably plays an important role in shoulder joint function. In this study, we assessed the effect of muscle fatigue on shoulder proprioception in 20 volunteers with no shoulder abnormalities. Shoulder proprioception was measured as the threshold to first detection of humeral rotation with the joint at 90° of abduction and 90° of external rotation. Subjects were tested while rested, exercised on a isokinetic testing machine until fatigued, and then retested in an identical fashion. Both shoulders were tested, and the order of dominant and non-dominant shoulder was randomized. Shoulder proprioception was analyzed for its dependence on arm dominance, direction of rotation, and muscle fatigue. Subjects detected external rotation after significantly less movement than they did internal rotation. Overall, before exercise, motion was detected after a mean of 0.92° of rotation. After exercise, this threshold to detection of movement increased to 1.59°, an increase of 73%. This significant increase occurred with both internal and external rotation. The decrease in proprioceptive sense with muscle fatigue may play a role in decreasing athletic performance and in fatigue-related shoulder dysfunction. It remains to be determined if training can lessen this loss in position sense.

A study to determine the sensitivity, specificity, and positive and negative predictive values of several clinical diagnostic tests of subcutaneous Achilles tendon rupture was performed during a 13-year period. There were 174 patients with clinical diagnosis of unilateral complete subcutaneous Achilles tendon tear and 28 patients with unilateral suspected but no actual Achilles tendon tear. The following tests were used: palpation, calf squeeze, Matles, Copeland, and O'Brien. Palpation of the gap was the least sensitive clinical test with the patient awake (0.73), increasing to 0.81 when the test was performed under anesthesia; the Copeland and O'Brien tests showed a sensitivity of 0.8. Both the calf squeeze and Matles tests were significantly more sensitive than the other tests (0.96 and 0.88, respectively; 0.022 P 0.05). All tests showed a high positive predictive value, with no statistically significant difference between the various tests. In the 28 patients with no evidence of a subcutaneous Achilles tendon tear on imaging, the tests showed a high capability to detect that the Achilles tendon was intact (gap palpation specificity, 0.89; calf squeeze test specificity, 0.93; Matles test specificity, 0.85). Whichever tests were performed, at least two of them were positive for a subcutaneous tear of the Achilles tendon in all patients in this study.

We undertook a prospective study to determine the type and distribution of foot and ankle snowboarding injuries. Reports of 3213 snowboarding injuries were collected from 12 Colorado ski resorts between 1988 and 1995. Of these, 491 (15.3%) were ankle injuries and 58 (1.8%) were foot injuries. Ankle injuries included 216 (44%) fractures and 255 (52%) sprains. Thirty-three (57%) of the foot injuries were fractures and 16 (28%) were sprains. The remaining injuries were soft tissue injuries, contusions, or abrasions. There was no significant correlation between boot type (soft, hybrid, or hard) and overall foot or ankle injury rate. There were significantly fewer ankle sprains in patients wearing hybrid boots and fewer fractures of the lateral process of the talus in patients wearing soft boots. An unexpectedly high number of fractures of the lateral process of the talus were noted. These 74 fractures represented 2.3% of all snowboarding injuries, 15% of all ankle injuries, and 34% of the ankle fractures. Many of these fractures are not visible on plain radiographs and require computed tomography imaging to be diagnosed. Diagnosis of this fracture pattern is paramount; the physician should be very suspicious of anterolateral ankle pain in the snowboarder, where subtle fractures that may require surgical intervention can be confused with anterior talofibular ligament sprains.

We evaluated the effect of adjunctive healing measures on central tears of the adult goat medial meniscus and the role of magnetic resonance arthrography in the assessment of menisci that have undergone a repair. Peripheral tears were made unilaterally in the medial menisci of seven goats in Group I and repaired with nonabsorbable suture. Six Group II goats had central medial meniscal tears repaired as in Group I plus an exogenous fibrin clot. Eight Group III goats had central tears plus abrasion of the parameniscal synovium and tear edges. Six months after surgery, a magnetic resonance imaging scan and a magnetic resonance arthrogram were obtained and the menisci were examined grossly. Group I goats showed healing in all seven knees. Central tears repaired with a fibrin clot (Group II) showed healing in one of six knees (17%). Central tears repaired with abrasion (Group III) showed healing in seven of eight knees (87.5%). Magnetic resonance arthrography was 100% accurate in detecting the presence or absence of complete residual tears. This study supports the current trend of using adjunctive measures for repair of central tears. Furthermore, abrasion of the parameniscal synovium and the tear edges appears to be more effective than the use of an exogenous fibrin clot. Magnetic resonance arthrography is useful in the evaluation of menisci that have undergone repair.

This study characterized knee joint kinetics during a golf swing and determined the influence of shoe type and golfer skill on the peak knee joint loads. Thirteen golfers each hit a golf ball using a five iron under two footware conditions: spiked and spikeless golf shoes. Data from a video-based motion capture system and force plates were used to compute the knee joint kinetics. Mean peak forces and moments differed significantly between the lead and trail knees, but these peak loads were not significantly affected by shoe type. Only the lead knee flexion and internal rotation moments were significantly correlated to skill level. The magnitude of some of the peak loads at the knee during the golf swing approached those reached during activities prohibited until late-stage knee rehabilitation. We concluded the following: The type of shoe worn and the skill level of the golfer need not be considered in deciding time to return to golfing; however, the leg that is recovering from surgery or injury should be considered. The most stressful phase of the golf swing, relative to the knee, is the downswing. There is probably no “normal” swing; each golfer seems to possess consistent, characteristic, patterns of knee loading.

Articular cartilage can tolerate a tremendous amount of intensive and repetitive physical stress. However, it manifests a striking inability to heal even the most minor injury. Both the remarkable functional characteristics and the healing limitations reflect the intricacies of its structure and biology. Cartilage is composed of chondrocytes embedded within an extracellular matrix of collagens, proteoglycans, and noncollagenous proteins. Together, these substances maintain the proper amount of water within the matrix, which confers its unique mechanical properties. The structure and composition of articular cartilage varies three-dimensionally, according to its distance from the surface and in relation to the distance from the cells. The stringent structural and biological requirements imply that any tissue capable of successful repair or replacement of damaged articular cartilage should be similarly constituted. The response of cartilage to injury differs from that of other tissues because of its avascularity, the immobility of chondrocytes, and the limited ability of mature chondrocytes to proliferate and alter their synthetic patterns. Therapeutic efforts have focused on bringing in new cells capable of chondrogenesis, and facilitating access to the vascular system. This review presents the basic science background and clinical experience with many of these methods and information on synthetic implants and biological adhesives. Although there are many exciting avenues of study that warrant enthusiasm, many questions remain. These issues need to be addressed by careful basic science investigations and both short- and long-term clinical trials using controlled, prospective, randomized study design.

The exact role and the function of the scapula are misunderstood in many clinical situations. This lack of awareness often translates into incomplete evaluation and diagnosis of shoulder problems. In addition, scapular rehabilitation is often ignored. Recent research, however, has demonstrated a pivotal role for the scapula in shoulder function, shoulder injury, and shoulder rehabilitation. This knowledge will help the physician to provide more comprehensive care for the athlete. This “Current Concepts” review will address the anatomy of the scapula, the roles that the scapula plays in overhead throwing and serving activities, the normal biomechanics of the scapula, abnormal biomechanics and physiology of the scapula, how the scapula may function in injuries that occur around the shoulder, and treatment and rehabilitation of scapular problems.