bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of an iliotibial tenodesis on intraarticular graft forces and knee joint motion
Authors: Engebretsen Lars , Lew William D. , Lewis Jack L. , Hunter Robert E. 
Published: June 2007

Lateral extraarticular reconstructions are used as iso lated procedures in knees with moderate rotatory insta bility and as "backups" in knees requiring primary repair or intraarticular reconstruction for major rotatory insta bility. We used an experimental knee testing system to analyze the immediate postoperative mechanical effect of an iliotibial band tenodesis on an intraarticular recon struction of the ACL in fresh cadaver knees using a composite graft consisting of a bone-patellar tendon- bone segment augmented with the Kennedy Ligament Augmentation Device (LAD, 3M Co., St. Paul, MN). The intraarticular graft was standardized by using a force- setting technique. Ligament and graft forces were measured using buckle transducers, and joint motion was measured using an instrumented spatial linkage as 90 N anteriorly directed tibial loads were applied to seven fresh knee specimens at 0°, 30°, 60°, and 90° of flexion. The following knee states were tested in each specimen: intact ACL, excised ACL, intraarticular reconstruction, intraarticular reconstruction with the tenodesis added, and tenodesis with the intraarticular reconstruction added. Adding the iliotibial band tenodesis to an existing standardized intraarticular reconstruction significantly decreased the force in the ACL composite graft by an average of 43%. When the standardized intraarticular reconstruction was added to an existing tenodesis, the graft forces were an average of 15% below the level of when the reconstruction was performed alone. The force in the tenodesis was significantly less than the composite graft force at extension; however, the differ ences between the tenodesis and total graft force were not significant from 30° to 90° of flexion. Load sharing appeared to occur between the tenodesis and intraar ticular graft. The tenodesis caused the tibia to be in an externally rotated configuration relative to normal, po tentially interfering with the "screw home mechanism."
Percutaneous and open surgical repairs of Achilles tendon ruptures
Authors: Bradley James P. , Tibone James E. 
Published: June 2007

A comparative study between percutaneous repair and open surgical repair of acute spontaneous Achilles ten don ruptures in young athletic patients is presented. Twenty-seven patients with acute Achilles ruptures were evaluated objectively and with subjective ques tionnaires. Fifteen of the patients were treated by re construction with a gastrocsoleus fascial graft (fol lowup, 4.6 years) and 12 treated by percutaneous repair (followup, 1.8 years). Subjectively, both groups were very satisfied with the results of their treatment. Cybex II dynamometer measuring strength, power, and endurance revealed no statistical significant differences between groups, even in light of the shorter followup of the percutaneous group. The percutaneous repairs demonstrated signifi cantly more symmetry in injured/uninjured tendon size than did the open surgical repairs. Two reruptures occurred in the percutaneous group. No other compli cations were noted. After evaluation of both subjective and objective data we recommend percutaneous repair in the recreational athlete and in patients concerned with cosmesis. Open repair is recommended for all high-caliber athletes who cannot afford any chance of rerupture.
Altered timing of hamstring muscle action in anterior cruciate ligament deficient patients
Authors: Kålund Søren , Sinkjær Thomas , Arendt-Nielsen Lars , Simonsen Ole 
Published: June 2007

Recent studies indicate that the hamstrings are essen tial antagonists in ACL deficient patients. In order to evaluate muscle coordination under physiologic condi tions, nine patients with arthroscopically verified total ACL ruptures were compared with nine control volun teers. This comparison was made from electromy ograms of the thigh muscles and heel contact record ings made while walking on a treadmill. While walking on a horizontal level, the patient's muscle activity did not differ from controls, but when the knee load was increased by walking uphill, the hamstring muscles in patients were activated signifi cantly earlier than among controls. It is proposed that an altered muscle coordination is probably essential in ACL deficient patients to secure knee stability. This study suggests a new approach to investigate the coordination of muscles under physiologic conditions in ACL deficient patients, and may guide rehabilitation programs in the future.
Clinical comparison of freeze-dried and fresh frozen patellar tendon allografts for anterior cruciate ligament reconstruction of the knee
Authors: Indelicato Peter A. , Bittar Edward S. , Prevot Troy J. , Woods Gregory A. , Branch Thomas P. , Huegel Marty 
Published: June 2007

The aim of this study was to evaluate the clinical outcome of freeze-dried compared to fresh frozen al lograft tissue used as a substitute for a ruptured ACL of the knee. In addition, the incidence of any graft rejection phenomena was recorded. Forty-one patients with ACL deficient knees underwent reconstructive sur gery using a patellar bone-tendon-bone allograft that had been freeze-dried (Group 1, N = 14) or fresh frozen (Group 2, N = 27). All patients underwent the same implant technique and rehabilitation program. Followup ranged from 24 to 36 months. The evaluation consisted of subjective, objective, and instrumented laxity testing (KT-1000, MEDmetric, San Diego, CA; and Genucom, FARO Medical Technologies, Inc., Montreal, Canada). There were 31 males and 10 females. Eleven (79%) patients in Group 1 thought their knee was "normal" or "improved," and 25 (93%) in Group 2 thought the same. In addition, 10 (71%) patients in Group 1 denied any "giving way," compared to 26 (96%) in Group 2. The mean Lysholm knee score in Group 1 was 86/100 (range, 22 to 100) compared to 92/100 (range, 59 to 100). Clinical examination included the Lachman test and tests for anterior drawer sign and pivot shift. Postop eratively, Group 1 patients had the following results: Lachman test—seven Grade 0, six Grade 1, one Grade 2; anterior drawer sign—eight Grade 0, five Grade 1, one Grade 2; and pivot shift—seven Grade 0, five "trace," and two "present." In Group 2, the results showed the following: Lachman test—17 Grade 0, 10 Grade 1; anterior drawer sign, 20 Grade 0, 7 Grade 1; and pivot shift—23 Grade 0, 4 "trace." The KT-1000 mean left-right difference in Group 1 was 1.2 mm (0.0 to 4.0 mm) compared to 0.9 mm (0.0 to 3.0 mm) for Group 2. The Genucom mean left-right difference in Group 1 was 1.30 mm (0.0 to 3.0 mm) compared to 1.5 mm (0.0 to 9.0 mm) for Group 2. Overall, there was a marked improvement in both groups relative to overall subjective and objective re sults, the fresh frozen recipients doing slightly better than those who received a freeze-dried allograft. Statis tical analysis revealed a significant difference in only 3 of the 21 parameters evaluated. There was no clinical evidence of rejection phenomena in either group.
Patterns of flexibility, laxity, and strength in normal shoulders and shoulders with instability and impingement
Authors: Warner Jon J.P. , Micheli Lyle J. , Arslanian Linda E. , Kennedy John , Kennedy Richard 
Published: June 2007

Imbalance of the internal and external rotator muscu lature of the shoulder, excess capsular laxity, and loss of capsular flexibility, have all been implicated as etio logic factors in glenohumeral instability and impinge ment syndrome; however, these assertions are based largely on qualitative clinical observations. In order to quantitatively define the requirements of adequate pro tective synergy of the internal and external rotator musculature, as well as the primary capsulolabral re straints, we prospectively evaluated 53 subjects: 15 asymptomatic volunteers, 28 patients with glenohu meral instability, and 10 patients with impingement syndrome. Range of motion was evaluated by gonio metric technique in all patients with glenohumeral insta bility and impingement. Laxity assessment was per formed and anterior, posterior, and inferior humeral head translation was graded on a scale of 0 to 3+. Isokinetic strength assessment was performed in a modified abducted position using the Biodex Clinical Data Station with test speeds of 90 and 180 deg/sec. Internal and external rotator ratios and internal and external rotator strength deficits were calculated for both peak torque and total work. Patients with impingement demonstrated marked lim itation of shoulder motion and minimal laxity on drawer testing. Both anterior and multidirectional instability pa tients had excessive external rotation as well as in creased capsular laxity in all directions. Sixty-eight per cent of the patients with instability had significant im pingement signs in addition to apprehension and capsular laxity. Isokinetic testing of asymptomatic subjects demon strated a 30% greater internal rotator strength in the dominant shoulder. Comparison of all three experimen tal groups demonstrated a significant difference be tween internal and external rotator ratios for both peak torque and total work. Conclusions are that there appears to be a domi nance tendency with regard to internal rotator strength in asymptomatic individuals. Impingement syndrome and anterior instability have significant differences in both strength patterns of the rotator muscles and flex ibility and laxity of the shoulder. Isokinetic testing po tentially may be helpful in diagnostically differentiating between these two groups in cases where there is clinical overlap of signs and symptoms.
Isometric muscle strength and quantitative electromyography of back muscles in wrestlers and tennis players
Authors: Sward Leif , Svensson Magnus , Zetterberg Carl 
Published: June 2007

The isometric motor performance of the trunk muscles was studied in 10 male wrestlers and 9 male tennis players, all of whom were elite athletes. Isometric flex ion, extension, and lateral bending were performed. The motor output, including fatigue, was studied by means of a load cell and using electromyographγ. The wrestlers were found to have symmetrical strength and were stronger in all measured directions, especially in side bending (flexion, 852 N; extension, 951 N; right and left side bending, 759 N and 744 N, respectively), than the tennis players and normal sub jects of any published study. The development of fa tigue in the erector spinae muscles, as evaluated by spectral analysis of the myoelectric signal, was not symmetrical and was significant bilaterally at the lumbar level and on the right side at the thoracic level. As expected, the tennis players had asymmetrical isometric strength. They were stronger in left side bending than right side bending (643 N compared with 557 N, P < 0.01), and stronger in extension than flexion (835 N compared with 638 N, P < 0.01). The develop ment of fatigue in the erector spinae muscles was significant bilaterally at the lumbar level and on the left side at the thoracic level. The development of fatigue in the tennis players was less than that of the wrestlers except for the left tho racic measurement site. Our conclusions are that tennis players appear to be relatively weak in trunk flexion. The wrestlers displayed a development of fatigue that was asymmetrical and was of nearly the same degree as the tennis players, but on the opposite side.
Arterial abnormalities of the hand in athletes
Authors: Nuber Gordon W. , McCarthy Walter J. , Yao James S.T. , Schafer Michael F. , Suker Jacob R. 
Published: June 2007

Vascular lesions of the hand may be seen in athletes exposed to repetitive blunt trauma. Thirteen athletes seen from 1983 to 1988 experienced symptoms related to hand ischemia. Nine were professional baseball catchers. The majority of patients complained of chronic symptoms, including cold hypersensitivity (four pa tients), finger numbness (one), finger coolness (three), and finger blanching (three). Two patients had acute symptoms with sudden posttraumatic hand ischemia with finger and palmar pain. Diagnosis was established by history and physical examination and confirmed by noninvasive testing. Testing included use of Doppler examination and cold tolerance examination with thermistors. Two athletes required angiographic eval uation because of severe ischemia and continuous pain. All patients in this group were managed nonopera tively. Those with chronic complaints were counseled regarding cold avoidance and instructed to increase their glove padding. The two patients with acute symp toms required vasodilator (papaverine chloride) infu sion, followed by intravenous heparin and dextran. All baseball catchers returned to their sport with dissipa tion of symptoms.
Anterior tibial translation during a maximum quadriceps contraction: Is it clinically significant?
Authors: Howell Stephen M. 
Published: June 2007

Quadriceps exercises are used sparingly in the early rehabilitation of ACL reconstructions because of con cern about prematurely stretching the ACL graft. The aim of this study was to determine if a maximum isometric quadriceps contraction significantly translates the tibia anteriorly at 15°, 30°, 45°, 60°, and 75° of flexion. Secondly, the role of the ACL in knee stability was analyzed by comparing the amount of tibial trans lation in normal, ACL deficient, and reconstructed knees. Thirdly, the location in the motion arc where a quadriceps contraction produces anterior tibial transla tion was determined. Anterior tibial translation was measured using an arthrometer (KT-1000) during an 89 N and manual maximum translation applied to the knee at rest. The manual maximum translation test determines the mag nitude of anterior tibial translation produced by a high anterior force applied directly to the proximal calf. These translations were compared to the tibial translation intrinsically induced by a quadriceps contraction. Test ing was performed in normal ( N = 22), ACL deficient ( N=10), and reconstructed (N = 10) knees. Anterior tibial translation produced by a maximum quadriceps contraction was measured at 15°, 30°, 45°, 60°, and 75° of flexion. The extension exercise resulted in less anterior tibial displacement than an 89 N drawer and half the translation produced by a manual maximum translation (P < 0.001). Instrumented laxity testing pro duced greater anterior translation of the tibia than a maximum isometric quadriceps contraction. Anterior tibial translation was the same during maximum iso metric knee extension in all tested knees. Anterior translation in the isometrically loaded knee occurred during the terminal 60° of knee extension, and was controlled by the compression forces driving the con gruent articular surfaces together, and not the ACL. Instrumented laxity testing is an accepted technique that has been safely used to serially measure knee stability after an ACL reconstruction. Early postopera tive knee extension exercises can be expected to in duce less strain in the ACL than instrumented laxity testing. These data raise the question of whether the anterior tibial displacement produced by a maximum quadriceps contraction is detrimental to a recently re constructed ACL.
An analysis of the pivot shift phenomenon
Authors: Noyes Frank R. , Grood Edward S. , Cummings John F. , Wroble Randall R. 
Published: June 2007

The description of the pivot shift test and its modifica tions is for the most part based on clinical observations. We wished to precisely determine the knee motions and medial-lateral tibiofemoral compartment subluxa tions that examiners induce in the knee joint to produce the pivot shift phenomenon. Eleven skilled knee sur geons performed the pivot shift test on an instrumented cadaveric lower limb. The anterior cruciate and super ficial medial collateral ligaments (long fibers) of one limb were sectioned to produce an abnormal state. An in strumented spatial linkage allowed all six degrees of freedom motions to be measured. Before and after ligament sectioning we determined the limits of knee motion under defined loading conditions. The tibial and femoral bony landmarks were digitized to determine the positions of the medial and lateral tibial plateaus in reference to the femoral condyles during the pivot shift tests. Each examiner performed his pivot shift test. The analysis of the data showed that examiners typically induced a coupled anterior translation and internal tibial rotation to produce an anterior tibial subluxation, and a coupled posterior translation and external tibial rotation to induce the reduction event. The magnitude of ante rior subluxation of each plateau depended upon the examiner's technique. The maximal anterior subluxa tion of the lateral tibial plateau varied from 14 to 19.8 mm (mean, 17.2 ± 2.0 mm), whereas anterior sublux ation of the medial tibial plateau ranged from 6 to 16.9 mm (mean, 11.2 ± 3.3 mm). This variation was due to the different amounts of internal tibial rotation that an examiner induced in the knee. Increased internal rota tion significantly limited the amount of anterior sublux ation of the medial tibial plateau (P < 0.01). Conversely, increased external tibial rotation (after the reduction event) induced anterior subluxation of the medial tibial plateau. We concluded that more diagnostic information on the magnitude of the anterior knee subluxation in the anterior cruciate deficient knee is available by perform ing the pivot shift test starting with the tibia in external rotation and using a technique that enhances anterior tibial translation and avoids excessive internal tibial rotation. We also concluded that grading of the pivot shift test would vary considerably because of the dif ferences we measured between examiners. We believe there is an unmet need for reliable measurement of medial and lateral tibiofemoral rotational subluxations under specified loading conditions.
Tibial meniscal dynamics using three-dimensional reconstruction of magnetic resonance images
Authors: Thompson William O. , Thaete F. Leland , Fu Freddie H. , Dye Scott F. 
Published: June 2007

The human knee joint represents a complex biome chanical system of which the menisci are an integral component. At present, little data exists describing the meniscal kinematics of the intact knee. Accordingly, a three-dimensional reconstruction magnetic resonance image model was used to explore this issue. Five fresh cadaveric knees were examined by mag netic resonance imaging throughout a full range of motion at 10° intervals. Computer three-dimensional images of the menisci were generated and evaluated for anteroposterior excursion and deformation. During flexion, the posterior excursion of the medial meniscus was 5.1 mm, while that of the lateral meniscus was 11.2 mm. The anterior horn segments were shown to be more mobile than the posterior horn segments bilat erally. Prior limitations of meniscal kinematic assessment may be overcome with advanced imaging techniques such as magnetic resonance imaging and three-dimen sional reconstruction. The menisci are highly mobile and easily deformed structures within the intact, cadav eric knee. This imaging technique may prove useful in the elucidation of meniscal dynamics. In the future, similar techniques may be applied clinically to aid in the diagnosis of joint dysfunction.
Biomechanics of the golf swing in players with pathologic conditions of the forearm, wrist, and hand
Authors: Cahalan Thomas D. , Cooney William P. , Tamai Kazuo , Chao Edmund Y.S. 
Published: June 2007

Golf is an activity generally stressful to the hands and wrists and particularly can produce increasing symp toms in players with underlying problems such as hand and wrist arthritis or tendinitis. The purpose of this study was to quantitate wrist motion and club head/ ball impact force in subjects with pathologic conditions of the hand, wrist, or forearm, within a laboratory environment. A regular straight-handled golf club was compared to a new BioCurve handle design that has a 19° ulnar bend. We measured and compared the effect of the two grips on wrist motion, club head velocity, ball impact force, ball impact location, and isometric torsional strength in 20 subjects who had a variety of upper extremity disorders. This data was then com pared to data collected in an identical fashion from golfers without such conditions. The results of our study show that there were no differences related to club handle design on impact force or impact location, club head velocity, or club head path and face angle. Wrist kinematic differences were minimal between handle designs. The differences that were significant (P < 0.05) centered around the decreased ulnar deviation of the left hand that resulted when subjects used the BioCurve handle design, which also allowed greater resistance to torque than the straight grip club. In addition to collecting objective data, we asked subjects for their opinions of the two grips. As a whole, the normal group and the group with pathologic conditions noted more comfort, improved grip, and less shock transmission with the BioCurve handle.
Syndesmotic ankle sprains
Authors: Boytim Mark J. , Fischer David A. , Neumann Larry 
Published: June 2007

In this study we reviewed ankle sprains in a professional football team over a 6 year period. Fifteen players who sustained syndesmotic ankle sprains were compared with 28 players who sustained significant lateral ankle sprains. Players with syndesmotic sprains missed sig nificantly more games and practices and they received substantially more treatments than players with lateral ankle sprains. Physical examination findings, results of radiographic evaluations, and etiologic factors are dis cussed. The external rotation stress test, a clinical method for diagnosis of this type of sprain at the time of injury, is described. Results of this study clearly demonstrate a prolonged recovery time for syndesmotic ankle sprains. Physi cians and trainers who are aware of this injury can differentially diagnose these two types of sprains in the early postinjury period by the method described.
The O'Donoghue triad revisited
Authors: Shelbourne K. Donald , Nitz Paul A. 
Published: June 2007

We identified 60 consecutive patients with combined anterior cruciate and medial collateral ligament (ACL- MCL) disruptions that were incurred during athletic endeavors. Each underwent acute reconstruction of the ACL. The arthroscopic data obtained at the time of reconstructive surgery was reviewed in order to deter mine the incidence of O'Donoghue's triad (the "unhappy triad"), consisting of ACL, MCL, and medial meniscus tears. Patients were subdivided into two groups for analysis based upon the degree of MCL injury at time of pres entation (Group I, 35 patients with a second-degree sprain; Group II, 25 patients with a complete, or third- degree injury). Medial meniscus tears were an uncom mon finding. Lateral meniscus tears significantly out numbered medial meniscus tears in both groups, oc curring in 25 (71 %) of Group I patients and 8 (32%) of those in Group II. Even chondral fractures of the lateral femoral condyle outnumbered medial meniscus tears [6 (17%) versus 4 (11 %)] in patients with a second- degree MCL sprain. Furthermore, when present in Group I patients, tears of the medial meniscus were associated with a concomitant lateral meniscus injury. Group II patients were more likely (60%) than Group I not to have any meniscal abnormality at all. We conclude that the classic O'Donoghue triad is, in fact, an unusual clinical entity among athletes with knee injuries; it might be more accurately described as a triad consisting of ACL, MCL, and lateral meniscus tears. This injury combination appears to be more common when an incomplete, or second-degree, tear of the medial collateral has occurred. Third-degree MCL injuries in conjunction with ACL disruptions seem to "protect" joint surfaces, as patients with these injuries most commonly demonstrate an absence of further intraarticular abnormality (meniscal or chondral).