bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrinsic risk factors for exercise-related injuries among male and female army trainees
Authors: Jones Bruce H. , Bovee Matthew W. , Harris John McA. , Cowan David N.
Published: June 2007

Physical training-related injuries are common among army recruits and other vigorously active populations, but little is known about their causation. To identify intrinsic risk factors, we prospectively measured 391 army trainees. For 8 weeks of basic training, 124 men and 186 women (79.3%) were studied. They answered questionnaires on past activities and sports participa tion, and were measured for height, weight, and body fat percentage; 71 % of the subjects took an initial army physical training test. Women had a significantly higher incidence of time-loss injuries than men, 44.6% com pared with 29.0%. During training, more time-loss in juries occurred among the 50% of the men who were slower on the mile run, 29.0% versus 0.0%. Slower women were likewise at greater risk than faster ones, 38.2% versus 18.5%. Men with histories of inactivity and with higher body mass index were at greater injury risk than other men, as were the shortest women. We conclude that female gender and low aerobic fitness measured by run times are risk factors for training injuries in army trainees, and that other factors such as prior activity levels and stature may affect men and women differently.
Prevention of running injuries by warm-up, cool-down, and stretching exercises
Authors: van Mechelen Willem , Hlobil Hynek , Kemper Han C.G. , Voorn Wim J. , de Jongh H. Rob
Published: June 2007

The purpose of this study was to evaluate the effect of a health education intervention on running injuries. The intervention consisted of information on, and the sub sequent performance of, standardized warm-up, cool- down, and stretching exercises. Four hundred twenty- one male recreational runners were matched for age, weekly running distance, and general knowledge of preventing sports injuries. They were randomly split into an intervention and a control group: 167 control and 159 intervention subjects participated throughout the study. During the 16-week study, both groups kept a daily diary on their running distance and time, and reported all injuries. In addition, the intervention group was asked to note compliance with the standardized program. At the end of the study period, knowledge and attitude were again measured. There were 23 injuries in the control group and 26 in the intervention group. Injury incidence for control and intervention sub jects was 4.9 and 5.5 running injuries per 1000 hours, respectively. The intervention was not effective in re ducing the number of running injuries; it proved signifi cantly effective (P < 0.05) in improving specific knowl edge of warm-up and cool-down techniques in the intervention group. This positive change can perhaps be regarded as a first step on the way to a change of behavior, which may eventually lead to a reduction of running injuries.
Percutaneous Achilles tendon repair
Authors: Fitzgibbons Robert E. , Hefferon John , Hill James
Published: June 2007

Fourteen patients underwent percutaneous Achilles tendon repairs between 1982 and 1989 for ruptures approximately 2 to 8 cm from the calcaneal insertion. They were evaluated subjectively (questionnaires) and objectively (physical examinations, Cybex II dynamom eter). The minimum follow-up time was 2 years with an average of 3.8 years. Subjectively, all of the patients were satisfied with their overall results. Objectively, no significant difference was demonstrated by Cybex II evaluation at 60 and 120 deg/sec. A significant differ ence was seen at 180 deg/sec, but this represented only a 13% loss of power. No infections, delayed wound healing, reruptures, or evidence of thrombophlebitis were noted. There was one sural nerve injury.
The quantitative measurement of normal passive medial and lateral patellar motion limits
Authors: Skalley Thomas C. , Terry Glenn C. , Teitge Robert A.
Published: June 2007

To quantify normal motion, medial and lateral passive patellar motion limits were measured in 67 high school athletes randomly selected from a group of 1340 ath letes undergoing preseason physical examinations. Pa tellar displacement was measured at knee flexion an gles of 0° and 35°, using both a Patella Pusher (a hand held force gauge) and a manual technique, and the results were compared. Demographic data and physical examination of the deceleration mechanism (Q angle, vastus medialis obliquus dysplasia, patella alta and baja, and valgus and varus alignment) were correlated with patellar motion limits.

With the knee in extension, passive displacement of the patella averaged 9.6 mm medially and 5.4 mm laterally. In flexion, medial displacement averaged 9.4 mm and lateral displacement averaged 10.0 mm. No positive correlations were found between demographic data or deceleration mechanism examination parame ters and patellar motion limits, suggesting that motion produced by the displacement force was limited by ligamentous restraints only.

The clinical assessment of the passive limits of pa tellar motion should include examination at knee flexion angles of 0° and 35°. The manually produced displace ment was found to be more reproducible than displace ment by the Patella Pusher (P < 0.05).
Effects of prophylactic knee bracing on lower extremity joint position and muscle activation during running
Authors: Osternig Louis R. , Robertson Rick N.
Published: June 2007

The primary purpose of a prophylactic knee brace is to decrease injury potential without compromising joint function; however, the extent that these devices can alter knee muscle function is not clear. This study investigated effects of nonprescription prophylactic knee bracing on lower extremity joint position and muscle activation during running. Six healthy male col lege-aged recreational runners used a motor-driven treadmill under 6 conditions: fast or slow speeds, with and without wearing a prophylactic knee brace, and with and without wearing a weighted vest. Changes in hip, knee, and ankle joint position and electromyo graphic activity from 9 lower extremity muscles were monitored during the running cycle weightbearing phase. Results revealed significant changes (P < 0.05) in joint position and electromyographic activity for com parisons of slow versus fast, braced versus nonbraced, and weighted versus nonweighted conditions. From 83% to 89% of the braced and nonbraced comparisons generated significant differences in knee joint position while significant hip and ankle joint position changes occurred in 50% to 58% of comparisons. From 67% to 83% of braced and nonbraced comparisons for the 9 muscles produced significant differences in electromyo graphic activity. Findings suggest that neuromuscular control is altered when external prophylactic devices are applied.
The accuracy of the clinical knee examination documented by arthroscopy
Authors: Oberlander Michael A. , Shalvoy Robert M. , Hughston Jack C.
Published: June 2007

The diagnostic accuracy of the clinical examination for intraarticular injuries of the knee was documented by arthroscopy over a 6-month period. Two-hundred ninety patients (296 knees) were evaluated by history, physical examination, and standard radiographs. Supplemental diagnostic studies included 41 magnetic resonance images, 2 arthrograms, and 1 previous ar throscopy that had been recently performed.

Overall, the correct diagnosis was made in 165 knees (56%), an incomplete diagnosis in 92 (31%), and an incorrect diagnosis in 39 (13%). There were only 2 knees (0.07%) with no discernable lesions. When a single lesion was present in the knee, the diagnosis was made correctly in 72% of cases. When more than 2 were discovered, the diagnosis was correct in only 30%. However, all individual lesions were diagnosed with an accuracy of greater than 90%.

The lesions most difficult to diagnose were chondral fractures, fibrotic fat pads, tears in the anterior cruciate ligament, and loose bodies. Knees with acute lesions and those with a single diagnosis proved to be signifi cantly easier to diagnose (P < 0.01). The variables that proved to be insignificant were age, sex, magnetic resonance imaging, surgeon, workers' compensation, or pending litigation.
Skier's thumb—the significance of bony injuries
Authors: Hintermann Beat , Holzach Peter J. , Schütz Michael , Matter Peter
Published: June 2007

In a retrospective study to determine the anatomic nature of injuries in thumbs that were treated surgically for either fracture or instability, we reviewed 63 con secutive patients with acute skier's thumb injury. Of the 63 thumbs, 25 (40%) had a fracture. Surgical explo ration showed 2 fracture types: a fragment that was attached to the ulnar collateral ligament, and a fragment that was not attached to the ulnar collateral ligament. The 1 st type, corresponding to true avulsion fracture of the ulnar collaternal ligament, was found in 8 cases; the same fracture type was seen in another 7 cases, with an isolated fragment that was not attached to the ligament. Such an isolated fragment was observed in 10 other cases in which the ulnar collateral ligament was completely disrupted. This type of bony fragmen tation cannot be differentiated from a bony avulsion of the ulnar collateral ligament on routine films. Therefore, stress testing the injured thumb is mandatory even when bony avulsion fracture with minimal displacement is suspected from a radiograph, as indeed the fracture may not be a bony avulsion but may be a fragmentation of the ulnar volar aspect of the proximal phalanx as sociated with a complete disruption of the ulnar collat eral ligament.
The significance of isometer measurements and graft position during anterior cruciate ligament reconstruction
Authors: Colville Mark R. , Bowman Ronald R.
Published: June 2007

Intraoperative isometry measurements are commonly performed before bone tunnel drilling during anterior cruciate ligament reconstruction. The relationship be tween initial isometer measurements and final graft isometry, however, is unclear. We tested 15 cadaveric knees to determine the relationship between isometer readings and final graft isometry. We found that isometer readings may vary widely from final graft isometry because of eccentric placement of the anterior cruciate ligament graft within bone tunnels. Isometer measurements may be used, however, to predict ac curate final graft isometry for specific graft positions within the bone tunnels.
Anterior subcutaneous transfer of the ulnar nerve in the athlete
Authors: Rettig Arthur C. , Ebben James R.
Published: June 2007

To evaluate the effectiveness of subcutaneous subfas cial anterior transfer of the ulnar nerve in the surgical treatment of cubital tunnel syndrome in athletes, we retrospectively reviewed athletes undergoing subcuta neous anterior transfer of the ulnar nerve at the elbow. Criteria for inclusion in the study included active partic ipation in athletic activity, confirmed cubital tunnel syn drome, failure to respond to conservative treatment, and having an anterior subcutaneous subfascial trans fer as the only procedure performed. Twenty athletes underwent a total of 21 procedures. Results were evaluated by time to return to sport and a questionnaire developed to evaluate elbow function in the athlete.

The athletes returned to full activity at an average of 12.6 weeks. Average subjective postoperative scores were 84. Elbow rating scores averaged 9 (range, 0 to 10).

Anterior subcutaneous subfascial transfer of the ulnar nerve is a safe, effective means for treating cubital tunnel syndrome in athletes. The findings in this study are significant in that they confirm the effectiveness of the subcutaneous subfascial transfer procedure in re turning the athlete to competition. Of secondary impor tance is the development of an elbow rating question naire appropriate to the athlete.
Intraarticular abnormalities in association with posterior cruciate ligament injuries
Authors: Geissler William B. , Whipple Terry L.
Published: June 2007

The effect of an isolated injury of the posterior cruciate ligament on the articular cartilage and menisci has not been extensively studied. Intraarticular abnormalities in 88 arthroscopically proven posterior cruciate ligament tears in symptomatic patients with straight unidirec tional posterior instability were reviewed. There were 33 patients with acute injuries (range, 3 to 21 days; mean, 14) and 55 patients with chronic tears (range, 28 to 3650 days; mean, 786). Of the acute injuries, chondral defects occurred in 4 patients (12%) and meniscal tears in 9 patients (27%; 6 lateral and 3 medial). Chondral defects of both the lateral femoral condyles and patella were present in all 4 patients. Of the chronic injuries, chondral defects occurred in 27 (49%) and meniscal tears in 20 patients (36%) (7 lateral and 17 medial). Chondral defects of the medial femoral condyle were most common. The mechanism of injury resulting in an isolated injury of the posterior cruciate ligament is most likely to affect the lateral compartment or the articular cartilage of the patella. The incidence of articular defects and the incidence of meniscal tears increased in patients with chronic posterior cruciate ligament injuries; both lesions increased most in the medial compartment.
Medial Collateral Ligament Knee Sprains in College Football
Authors: Albright John P. , Powell John W. , Smith Walter , Martindale Al , Crowley Edward , Monroe Jeff , Miller Russ , Connolly John , Hill Billy A. , Miller Dennis , Helwig Dennis , Marshall Jim
Published: June 2007

In this prospective, multiinstitutional analysis of medial collateral ligament sprains in college football players, we categorized 987 previously uninjured study subjects according to frequency of wearing preventive knee braces, studied the patterns by which 47 of 100 injuries occurred to unbraced knees, and identified several ex trinsic, sport-specific risk factors shared for both braced and unbraced knees. The attendance, brace wear choice, position, string, and session of each participant were recorded daily; medial collateral ligament sprains were reported whenever tissue damage was confirmed. Both the likelihood of wearing braces and risk of injury without them was highly dependent on session (games/ practices), position group (line, linebacker/tight end, skill), and string group (players/nonplayers). Subjects wearing braces often faced a high injury risk to their unbraced knees, a finding compatible with the opinion that braces were a necessary evil, best worn when con cern over danger of injury outweighed desire for speed and agility. It is concluded that to avoid misinterpreta tions due to the confounding influence of brace wear selection bias, accurate investigation of daily brace wear patterns is required. Then, before considing the impact of preventive knee braces, a repartitioning of the data base is essential to assure that only similar groups will be compared.
Undersurface Tear of the Ulnar Collateral Ligament in Baseball Players
Authors: Timmerman Laura A. , Andrews James R.
Published: June 2007

Seven patients were diagnosed with an undersurface tear of the deep capsular layer of the anterior bundle of the ulnar collateral ligament. Preoperatively, all of the patients had tenderness over the anterior bundle of the ulnar collateral ligament and pain with valgus stressing of the elbow. Six of the seven patients had a normal magnetic resonance imaging scan, with one magnetic resonance imaging scan showing degeneration within the ligament. All of the patients had a negative com puted tomography arthrogram for extracapsular con trast extravasation. A consistent finding in five of the seven patients was a leak of contrast around the edge of the humerus or ulna, although the contrast was con tained within the joint. At arthroscopic evaluation, all of the patients demonstrated medial elbow instability as valgus stress was applied across the elbow joint in 70° of flexion. All of the patients underwent open medial elbow surgery, where the ulnar collateral ligament was visualized and found to be intact externally. But when the anterior bundle was incised, there was a detach ment of the undersurface of the ligament at the ulna or the humerus. Cadaveric dissections were performed to define the anatomy of the insertion sites and to confirm that this lesion was not an anatomic variant. A tear of the deep layer of the ulnar collateral ligament can result in symptomatic instability that is difficult to diagnose with conventional preoperative testing. This lesion of the an terior bundle of the ulnar collateral ligament has not been previously reported, and in our series it was as sociated with persistent medial elbow pain in throwing athletes.
Early Mobilization Versus Immobilization in the Treatment of Lateral Ankle Sprains
Authors: Eiff M. Patrice , Smith Allen T. , Smith Gary E.
Published: June 2007

We conducted a prospective trial at a military medical center to determine which treatment for first-time ankle sprains, early mobilization or immobilization, is more effective. Eighty-two patients with a lateral ankle sprain were randomly selected for one of two treatment groups. The Early Mobilization Group received an elas tic wrap for 2 days followed by functional bracing for 8 days. Two days after injury, this group began weight bearing and an ankle rehabilitation program. Patients in the Immobilization Group were placed in a nonweight bearing plaster splint for 10 days followed by weight bearing and the same rehabilitation program. Patients in the Early Mobilization Group had less pain at 3 weeks (57% versus 87%, P = 0.02); otherwise, there were no significant differences between groups in the frequency of residual symptoms. Only one patient in each group had residual symptoms 1 year after injury. Three pa tients (8%) in each group resprained their ankles. Ten days after injury, patients in the Early Mobilization Group were more likely to be back to full work (54% versus 13%, P < 0.001). We conclude that in first-time lateral ankle sprains, although both immobilization and early mobilization prevent late residual symptoms and ankle instability, early mobilization allows earlier return to work and may be more comfortable for patients.
Infraspinatus Muscle-splitting Incision in Posterior Shoulder Surgery
Authors: Shaffer Benjamin S. , Conway John , Jobe Frank W. , Kvitne Ronald S. , Tibone James E.
Published: June 2007

Standard posterior shoulder surgical approaches include infraspinatus tendon detachment and infraspinatus-teres minor interval development. Cadav eric and clinical investigation of a new infraspinatus- splitting approach to the posterior glenohumeral joint was undertaken to assess efficacy in providing expo sure, preserving tendon attachment, and avoiding neu rologic compromise. Infraspinatus musculotendinous and neural anatomy was examined in 20 cadavers. Four patients with posterior shoulder instability underwent posterior capsulorrhaphy through this infraspinatus- splitting approach, followed by electrodiagnostic test ing. Infraspinatus muscle was bipennate in all speci mens, the tendinous interval an average 14 mm inferior to the scapular spine at the glenoid rim. The infraspinatus-splitting interval bisected the posterior glenoid rim at its midpoint, whereas the infraspinatus- teres minor interval crossed the glenoid rim's lower quarter. The suprascapular nerve provided sole inner vation to the infraspinatus muscle in all specimens, en tering the infraspinous fossa at the notch as a single trunk 22 mm medial to the glenoid rim. Minimum branch ing variability was observed. Electrodiagnostic testing showed no evidence of axonal damage or muscle de nervation in either infraspinatus pennate bundle. Lim iting infraspinatus-splitting dissection medially to 1.5 cm from the posterior glenoid rim prevents damage to any interval-crossing suprascapular nerve branches. Pos terior shoulder surgery through a horizontal, longitudi nal infraspinatus tendon-splitting approach provides ex cellent exposure of posterior capsule, labrum, and glenoid, without requiring tendon detachment or caus ing neurologic compromise.
Femoral Intercondylar Notch Stenosis and Correlation to Anterior Cruciate Ligament Injuries
Authors: LaPrade Robert F. , Burnett Quinter M.
Published: June 2007

To evaluate the possible relationship between femoral intercondylar notch stenosis and anterior cruciate liga ment injuries in pivoting and cutting sports, a 2-year prospective study was performed on intercollegiate ath letes at a Division I university. Daily practice times and athlete participation in practices and games were re corded for each sport during the 2-year period. Bilateral intercondylar notch view radiographs were taken of all athletes enrolled in the study. The notch width index, a ratio that measures the width of the anterior outlet of the intercondylar notch divided by the total condylar width at the level of the popliteal groove, was measured for each knee. A total of 213 athletes, representing 415 anterior cruciate ligament-intact knees, were enrolled in the study. There were 7 anterior cruciate ligament tears. Statistical analysis demonstrated a correlation between femoral intercondylar notch stenosis and anterior cru ciate ligament injuries. No statistical difference was found between the sex of the athlete and notch width indices or rate of anterior cruciate ligament tears. Ath letes with intercondylar notch stenosis appear to be at increased risk for noncontact anterior cruciate ligament injuries.
Arthroscopic Treatment of Posttraumatic Elbow Pain and Stiffness
Authors: Timmerman Laura A. , Andrews James R.
Published: June 2007

Nineteen consecutive cases of posttraumatic arthrofi brosis of the elbow secondary to a fracture or fracture- dislocation and treated with arthroscopic debridement and manipulation were retrospectively reviewed. All of the patients had pain and stiffness in their elbows, and all had failed a conservative therapy program. All 19 patients were followed postoperatively for an average of 29 months (range, 12 to 51). One hundred-point scoring systems were used to evaluate subjective (pain, swell ing, locking, and activities) and objective (range of mo tion) results.

The average preoperative subjective score of 39 im proved to 91 postoperatively (P= 0.0001); the objective score improved from 46 preoperatively to 81 postop eratively (P = 0.0001). Extension improved from a mean of 29° to 11 °; flexion improved from an average of 123° to 134°. Fourteen patients had limitations in their sports activity preoperatively; 11 were able to return to their preinjury levels of activity after surgery.

This study demonstrated good-to-excellent overall re sults in 79% of the patients treated with arthroscopic debridement for posttraumatic elbow arthrofibrosis. Al though complete return of preinjury motion was not ob tained, each patient showed a significant improvement in motion and subjective symptoms.
The Anterior Cruciate Ligament in Controlling Axial Rotation
Authors: Lane John G. , Irby Steven E. , Kaufman Kenton , Rangger Christoph , Daniel Dale M.
Published: June 2007

Changes in axial tibial rotation after anterior cruciate ligament sectioning were evaluated in 14 fresh human knee joints. Simulation of vertical stance in a quadriceps-stabilized knee was performed. Internal and external rotational torques were applied before and after anterior cruciate ligament sectioning. Pivot shift tests were done in the intact and anterior cruciate ligament sectioned knee. Results of pivot shift tests were all negative before sectioning and positive after isolated sectioning. No significant change in axial ro tation occurred between the intact and sectioned knee for external rotation (P = 0.24) or internal rotation (P = 0.12). Presence of a load at the femoral housing in both the intact and ligament-sectioned knees caused a significant change in external rotation (P < 0.0001). No significant change was noted in internal rotation between loaded and unloaded states (P = 0.70). Total tibial rotation in the intact knee was noted to vary between 31 ° at 0° of flexion and 42° at 60° of flexion. These results suggest that the anterior cruciate ligament does not play a significant role in limiting axial rotation and that rotational instability is not a major factor after isolated anterior cruciate liga ment rupture.
Muscle Functional Deficits After Tourniquet Ischemia
Authors: Jacobson Mark D. , Pedowitz Robert A. , Oyama Brian K. , Tryon Brian , Gershuni David H.
Published: June 2007

The contractile properties of the rabbit tibialis anterior muscle were studied 48 hours after an ischemic episode induced by pneumatic tourniquet compression of the thigh. Forty animals were divided into five groups, each of which had continuous ischemia of either 1, 2, or 4 hours, or a total of 2 or 4 hours of ischemia interrupted by 10 minutes of reperfusion at 1-hour intervals. Con tralateral limbs served as controls. Muscle contractile properties were tested by stimulation of the peroneal nerve distal to the site of tourniquet compression. Peak tetanic tension in the 1-hour group did not differ signifi cantly from controls. In the 2- and 4-hour groups, peak tetanic tensions were 31 % and 2% of controls, respec tively, and twitch tensions were 25% and 1 % of controls, respectively. Hourly reperfusion intervals had no sig nificant effect on maximum tetanic or twitch tension compared with continuous ischemia for either 2 or 4 hours.

Clinically significant muscle dysfunction may be in duced by 2 or more hours of pneumatic tourniquet ap plication. Hourly reperfusion intervals may not improve skeletal muscle function distal to the tourniquet. How ever, reperfusion intervals could still affect muscle that is compressed beneath the cuff. Tourniquet-induced contractile deficits may interfere with postoperative functional recovery.
Graft Impingement After Anterior Cruciate Ligament Reconstruction
Authors: Lane John G. , Daniel Dale M. , Stone Mary Lou
Published: June 2007

Twelve of 215 patients with an anterior cruciate liga ment reconstruction developed a "thunk," a low-pitched sound, on active extension of the operative knee at an average of 5 months after surgery. In 4 of the patients the thunk resolved without surgical treatment at an av erage of 4 months after onset (range, 2 to 6). In 3 of the patients an increase in anterior knee laxity was asso ciated with resolution of the thunk. Seven of the patients were treated with arthroscopic examination. Six of the patients had graft impingement on the lateral wall or the roof of the notch with knee extension. The thunk was eliminated with an adequate notchplasty that corrected the impingement. In the other patient the thunk was sec ondary to fibrosis of the anterior fat pad. One patient with a persistent thunk declined surgery and was lost to followup.
Treatment of Isolated Medial Collateral Ligament Injuries in Athletes with Early Functional Rehabilitation
Authors: Reider Bruce , Sathy Michael R. , Talkington James , Blyznak Nestor , Kollias Stephen
Published: June 2007

A prospective study was designed to provide 5-year fol lowup of the treatment of isolated grade I I I sprains of the medial collateral ligament with early functional rehabili tation in 35 athletes. After injury, patients were placed in lateral hinged braces to provide valgus support with out restricting flexion or extension of the knee. Treat ment was initiated with range of motion exercises per formed in a whirlpool or swimming pool. Patients were then started on quadriceps setting and leg raises. When 90° of flexion was present, resistive exercises were added. Upon recovery, patients were allowed to return to unrestricted sports. Followup consisted of both ques tionnaires and physical examination and was graded on the 50-point Hospital for Special Surgery scale. Mean followup was 5.3 years (range, 2.5 to 8); mean Hospital for Special Surgery knee rating score was 45.9 points (range, 41 to 50). These results are comparable with those achieved with surgery or immobilization by earlier investigators. Thus, early functional rehabilitation treat ment of complete medial collateral ligament sprains pro duces results comparable with those achieved with sur gery or immobilization while minimizing treatment- related morbidity and allowing more rapid return to sports participation.
Contribution of Axial Arm Rotation to Humeral Head Translation
Authors: Itoi Eiji , Motzkin Neil E. , Morrey Bernard F. , An Kai-Nan
Published: June 2007

The contribution of axial arm rotation to translation of the humeral head with the arm in the hanging position was examined using nine fresh-frozen cadaveric shoulders. Three standard clinical tests were simulated: anterior and posterior translation and sulcus tests. In both the anterior translation and sulcus tests, anterior and infe rior displacements were significantly restricted in inter nal rotation but not in neutral and external rotation. In the posterior translation test, no significant differences in displacement could be observed in internal, neutral, or external rotation. Since anterior and inferior translations of the humeral head were significantly affected by the rotation of the arm, we recommend that the anterior translation and sulcus tests be performed in various rotations.
Isokinetic Concentric Versus Eccentric Training of Shoulder Rotators with Functional Evaluation of Performance Enhancement in Elite Tennis Players
Authors: Mont Michael A. , Cohen David B. , Campbell Kevin R. , Gravare Karin , Mathur Sanjog K.
Published: June 2007

Thirty elite tennis players were randomly assigned to three groups to evaluate shoulder isokinetic internal and external rotation training: an isokinetic concentric group, an isokinetic eccentric group, and a control group with no training. Subjects were tested before and after training both concentrically and eccentrically using an isokinetic dynamometer. Functional output before and after training was assessed by the average and peak velocity of six maximal serves. The effect of training on serve velocity endurance was also assessed. Statisti cally significant concentric and eccentric strength gains (11 %) were obtained in both training groups when com pared with controls (decreased total average strain of 2%) (P < 0.0004). Serve velocity increased by greater than 11 % in both training groups, which was a signifi cant increase from the average of 1% in the control group (P < 0.0001). In the endurance study, training group subjects displayed a tendency to maintain their serve velocity (loss of approximately 2%) greater than controls (loss of 6.4%) ( P< 0.05). Isokinetic training led to increases in objective and functional output in elite tennis players. This training regimen may have signifi cance in the final stages of the rehabilitation of injured shoulders as well as in improved performance and re duced injury risk.
Biomechanical and Histologic Assessment of a Controlled Muscle Strain Injury Treated with Piroxicam
Authors: Obremsky William T. , Seaber Anthony V. , Ribbeck Beth M. , Garrett William E.
Published: June 2007

This study was designed to observe the effect of the nonsteroidal antiinflammatory piroxicam on a controlled muscle strain injury in the rabbit model. The tibialis an terior tendons of 90 New Zealand White rabbits were detached at their distal insertions, and the right tendon was stretched to the yield point of the deformation curve. One group of 50 rabbits received piroxicam treat ment and the others received no treatment. At 1, 2, 4, and 7 days the parameters of muscle function, tensile strength, and histology were examined. Muscle con tractile force was significantly greater in the piroxicam- treated group at Day 1, but no difference was noted at any other time period. Tensile strength was not signifi cantly different at any time period in either group. His tology revealed delayed degradation of damaged tissue and slowed regeneration of muscle tissue at the injury site in the piroxicam-treated group.

Piroxicam and other antiinflammatories are fre quently given to athletes being treated for muscle strain injuries to control pain through their effect on the in flammatory process. This study demonstrates that pi roxicam does not adversely influence the recovery of contractile and tensile strength in a followup period of 1 week. Therefore, antiinflammatory treatment may be beneficial early in the course of muscle injury.
The Effects of Freeze-drying and Ethylene Oxide Sterilization on the Mechanical Properties of Human Patellar Tendon
Authors: Bechtold Joan E. , Eastlund D. Ted , Butts Michael K. , Lagerborg David F. , Kyle Richard F.
Published: June 2007

Human patellar tendon allografts are used to replace injured anterior cruciate ligaments. They are often stored by freeze-drying or freezing before use and have been sterilized by gamma irradiation or ethylene oxide gas. Studies comparing the mechanical properties of tendons preserved by freeze-drying and sterilized by ethylene oxide have yielded conflicting results. This study examined the effects of freeze-drying and ethyl ene oxide sterilization on the mechanical properties of human patellar tendons obtained from 11 human ca davers ; all were free of musculoskeletal disease. The 22 patellar tendons were halved longitudinally; 7 were fro zen at -70°C for 8 weeks and served as controls; 8 were freeze-dried; and 7 were freeze-dried and sterilized with ethylene oxide gas. Ultimate tensile stress and longi tudinal strain were greater for frozen than for freeze- dried, but not greater than freeze-dried, ethylene oxide- sterilized tendons (P < 0.05). The modulus of elasticity was similar in all tendon groups. The study suggests that some in vitro mechanical properties of frozen ten dons may be marginally superior to the properties of freeze-dried tendons, even after correction for size dif ference. Ethylene oxide gas sterilization had no adverse effect on tendon mechanical properties.
Arthroscopic Bankart Repair Versus Nonoperative Treatment for Acute, Initial Anterior Shoulder Dislocations
Authors: Arciero Robert A. , Wheeler James H. , Ryan John B. , McBride John T.
Published: June 2007

A prospective study evaluating nonoperative treatment versus arthroscopic Bankart suture repair for acute, ini tial dislocation of the shoulder was undertaken in young athletes. All patients met the following criteria: 1) sus tained an acute first-time traumatic anterior dislocation, 2) no history of impingement or occult subluxation, 3) the dislocation required a manual reduction, and 4) no concomitant neurologic injury. Thirty-six athletes (average age, 20 years) met the criteria for inclusion. Group I patients were immobilized for 1 month followed by rehabilitation; they were allowed full activity at 4 months. Group II patients underwent arthroscopic Bankart repair followed by the same protocol as Group I. Group I consisted of 15 athletes. Twelve patients (80%) developed recurrent instability; 7 of the 12 have required open Bankart repair for recurrent instability. Group I consisted of 21 patients; 18 patients (86%) had no recurrent instability at last followup (average, 32 months; range, 15 to 45) (P = 0.001). One patient in Group II has required a subsequent open Bankart repair to treat symptomatic recurrence (P = 0.005).

In this study, arthroscopic Bankart repair significantly reduced the recurrence rate in young athletes who sustained an acute, initial anterior dislocation of the shoulder.
Soft Tissue Reconstruction in the Shoulder
Authors: Shall Lawrence M. , Cawley Patrick W.
Published: June 2007

We evaluated three mechanical soft tissue fixation de vices (SuperAnchor, Suretac, and the Instrument Makar [IM] Bioabsorbable Staple) in a cadaveric model by ex amining ultimate tensile failure and modes of failure in simulated Bankart repairs. We attempted to realistically evaluate the strengths of soft tissue reattachment pro cedures at the anterior glenoid under worst-case conditions—load to failure. Twenty fresh-frozen cadav eric shoulders were used in this investigation. Each of the three techniques was performed in each anterior glenoid rim at one of three locations: superior, middle, or inferior. The subscapularis muscle-tendon was har vested, used in the repair, and loaded to failure. The mean load at failure for the SuperAnchor was 217.32 N; for the IM Staple, 132.32 N; and for the Suretac, 122.37 N. A two-sample t-test demonstrated that the load at failure for the SuperAnchor was statistically greater (P < 0.001) when compared with the IM Staple and Sure tac. There was no statistical difference between load at failure for the Suretac and the IM Staple. The most com mon failure mode for the Mitek was suture breakage (71 %). Anchor pullout from bone was the most common failure modeforthe IM Staple (75%) and Suretac (94%).
The Prevalence of Abnormal Magnetic Resonance Imaging Findings in Asymptomatic Knees
Authors: LaPrade Robert F. , Burnett Quinter M. , Veenstra Mark A. , Hodgman C. Gregory
Published: June 2007

The purpose of this study was to prospectively evaluate the prevalence of abnormal magnetic resonance imag ing scans of the knees of asymptomatic subjects. A pro spective analysis of magnetic resonance imaging to ar throscopic findings in symptomatic knees was also performed. The prevalence of meniscal tears found in asymptomatic knees was 5.6% (medial meniscus, 1.9%; lateral meniscus, 3.7%). Other abnormal findings included a prevalence of 1.9% for degenerative changes of the medial femoral condyle and 3.7% both for ganglion cysts and patellofemoral joint articular car tilage degenerative changes. There was also a preva lence of 24.1% of Grade II signal changes of the posterior horn of the medial meniscus. Statistical comparison of our results to previous studies revealed that the magnetic resonance imaging scan readings on the asymptomatic knees in this study were accurate and lesions were correctly identified. We recommend that clinicians match clinical signs and symptoms with mag netic resonance imaging findings before instituting sur gical treatment because of a 5.6% prevalence of meniscal tears in the asymptomatic population. The sig nificance of the high percentage of posterior horn medial meniscal Grade II signal changes is unknown.
The Relationship Between Anterior-Posterior Knee Laxity and the Structural Properties of the Patellar Tendon Graft
Authors: Beynnon Bruce D. , Johnson Robert J. , Toyama Harukazu , Renström Per A. , Arms Steven W. , Fischer Richard A.
Published: June 2007

We studied the relationship between anterior-posterior knee laxity and the structural properties of autogenous patellar tendon grafts used to replace the anterior cru ciate ligaments in dogs 1 year after reconstruction. At 30° (full extension for the dog), 60°, and 90° of flexion a significant inverse correlation was found between anterior-posterior knee laxity and the ultimate failure strength of the graft. Likewise, at 60° and 90° of flexion a significant inverse correlation was found between knee laxity and the linear stiffness of the graft. In all cases, as knee laxity increased, the ultimate failure load and linear stiffness values of the graft were found to decrease. There was also a significant increase in anterior-posterior knee laxity of the reconstructed knees (produced by an increase in anterior translation of the tibia relative to the femur) compared with the contralat eral control knee. The group of dogs that underwent a sham operation without reconstruction of the anterior cruciate ligament had no change in anterior-posterior knee laxity or the structural properties of the anterior cruciate ligament. The clinical significance of this in vestigation is that knee laxity measurements demon strating an increase in anterior translation of the tibia relative to the femur during graft healing may indicate that the graft has weakened and reduced structural properties.
Dynamic Ankle Ultrasonography
Authors: Campbell David G. , Menz Anthony , Isaacs John
Published: June 2007

We have developed a noninvasive ultrasound tech nique that may be used to differentiate complete and incomplete acute tears of the anterior talofibular liga ment. Direct visualization of the ligament will demon strate the lesion in most cases and can be supple mented by an anterior drawer test with the ligament under direct vision. Seventeen athletes involved in sports and work that put high-demand pressure on their ankles underwent ultrasonic examination of their acute lateral ankle ligament injuries before surgical explora tion. Fourteen scans demonstrating a complete lesion of the anterior talofibular ligament were confirmed at operation. Three scans were equivocal; two of these patients had incomplete lesions of their anterior talo fibular ligaments and one patient had a complete tear that was not detected. We have found that the dynamic ultrasound test is a simple and reliable examination. We suggest that this technique is indicated where the extent of an acute lateral ligament injury requires further defi nition. Ankle ultrasonography may reduce the need for ankle arthrography.
Physical and Performance Characteristics of Successful High School Football Players
Authors: Williford Henry N. , Kirkpatrick Jane , Scharff-Olson Michele , Blessing Daniel L. , Nai Zhen Wang
Published: June 2007

The purpose of this investigation was to determine the performance and physiologic characteristics of a "suc cessful" American high school football team, and to compare the present values with values reported for other groups of high school, college, and professional players. For descriptive purposes, players were divided into two groups: backs (N = 8) and linemen (N = 10). Maximal aerobic power (VO2max) was determined from a maximal treadmill test, and body composition was evaluated by hydrostatic weighing. Maximal strength values were evaluated by one-repetition maximum bench press and squat test; the sit-and-reach test was used to measure flexibility. Speed and power were evaluated by a vertical jump and a 36.6-meter sprint. Results indicate that compared with other groups of col lege and professional players, as the level of compe tition increases so do height, weight, and fat-free weight of the players. Similar maximum oxygen consumption values were found for the present group when com pared with other groups of these players. From the strength and power standpoint, football players at all levels are becoming stronger. Incorporation of strength training programs has greatly improved strength and performance profiles of football players at all levels of competition.
Anterior Cruciate Ligament Strain Behavior During Rehabilitation Exercises In Vivo
Authors: Beynnon Bruce D. , Fleming Braden C. , Johnson Robert J. , Nichols Claude E. , Renström Per A. , Pope Malcolm H.
Published: June 2007

Before studying the biomechanical effects of rehabili tation exercises on the reconstructed knee, it is impor tant to understand their effects on the normal anterior cruciate ligament. The objective of this investigation was to measure the strain behavior of this ligament dur ing rehabilitation activities in vivo. Participants were pa tient volunteers with normal anterior cruciate ligaments instrumented with the Hall effect transducer. At 10° and 20° of flexion, ligament strain values for active exten sion of the knee with a weight of 45 N applied to a sub ject's lower leg were significantly greater than active motion without the weight. Isometric quadriceps muscle contraction at 15° and 30° also produced a significant increase in ligament strain, while at 60° and 90° of knee flexion there was no change in ligament strain relative to relaxed muscle condition. Simultaneous quadriceps and hamstrings muscles contraction at 15° produced a significant increase in ligament strain compared with the relaxed state but did not strain the ligament at 30°, 60°, and 90° of flexion. Isometric contraction of hamstrings muscles did not produce change in ligament strain at any flexion angle. Exercises that produce low or un strained ligament values, and would not endanger a properly implanted graft, are either dominated by the hamstrings muscle (isometric hamstring), involve quad riceps muscle activity with the knee flexed at 60° or greater (isometric quadriceps, simultaneous quadri ceps and hamstrings contraction), or involve active knee motion between 35° and 90° of flexion.
A Biomechanical Comparison of Lateral Retinacular Releases
Authors: Marumoto Jay M. , Jordan Christopher , Akins Rod
Published: June 2007

A lateral patellar retinacular release that transects the tendon of the vastus lateralis muscle may result in sig nificant complications. To avoid such complications, the superior extent must be limited, and maximizing the in ferior extent may be important in achieving an adequate release. The effective release of the patella from its lat eral retinaculum was examined for 2 incision lengths using 10 fresh-frozen human cadaveric knees and com paring the medial displacement of the patella relative to the femur for 3 study groups (control, intact retinacula; Group A, retinacula cut from the inferior third of the vas tus lateralis tendon down to the anterolateral arthro scopic portal; and Group B, retinacula cut from the in ferior third of the vastus lateralis tendon down to the tibial tubercle) when a 22-N medially directed force was applied to the patella with the knee at 30° and 60° of flexion. The extended release (Group B) resulted in a significantly more effective release when compared with the standard release (Group A) or control group. This technique may allow an adequate release of the patella while preserving the function of the vastus late ralis muscle.
Correlation of Joint Line Tenderness and Meniscal Lesions in Patients with Acute Anterior Cruciate Ligament Tears
Authors: Shelbourne K. Donald , Martini Douglas J. , McCarroll John R. , VanMeter Charles D.
Published: June 2007

We sought to evaluate the accuracy with which joint line tenderness is associated with meniscal lesions in knees with acute anterior cruciate ligament tears. The physical assessment of joint line tenderness was performed at a mean of 8 days after the initial injury in 173 patients who subsequently underwent anterior cruciate ligament re construction. Identification of meniscal lesions was documented at the time of anterior cruciate ligament reconstruction. Eighty-nine patients (51%) had medial joint line tenderness; of this subgroup, 40 (45%) had a medial meniscal tear. Eighty-four patients (49%) had no medial joint line tenderness; of this subgroup, 29 (35%) had a medial meniscal tear. Fifty-nine patients (34%) had lateral joint line tenderness; of this subgroup, 34 (58%) had a lateral meniscal tear. One hundred four teen patients (66%) had no lateral joint line tenderness; of this subgroup, 56 (49%) had a lateral meniscal tear. Medial joint line tenderness was 44.9% sensitive and 34.5% specific in predicting medial meniscal injury. Lat eral joint line tenderness was 57.6% sensitive and 49.1% specific in predicting lateral meniscal injuries. Therefore, we determined that the presence or absence of joint line tenderness in patients with an acute anterior cruciate ligament tear is not a reliable criterion to predict the likelihood of an associated meniscal tear.