bluuebunny/crossref_metadata_2025 huggingface dataset:
Early experience with the GORE-TEX polytetrafluoroethylene anterior cruciate ligament prosthesis
Authors: Indelicato Peter A. , Pascale Mark S. , Huegel Marty O.
Published: June 2007

A prospective study of 41 patients with acute and chronic ACL deficiency underwent reconstruction with the GORE-TEX polytetrafluoroethylene (PTFE) ACL prosthesis beginning in November 1983. Thirty-nine patients who were at least 2 years from their surgical procedure were available for follow-up evaluation, which included subjective questionnaire, clinical exam ination, and instrumented ligamentous laxity tests. Eight patients had an acute injury to the ACL and 31 patients had chronic ACL insufficiency for which recon struction was performed.

Thirty-four patients had satisfactory results, allowing full return to activity with no appreciable symptomatol ogy. Of the remaining five patients, four had a complete rupture of the prosthesis. The average knee arthrome tric measurement improved from a 5.4 mm left/right difference preoperatively to a 2.0 mm left/right differ ence at 2 year followup. Nine patients had postopera tive complications of one or more atraumatic episodes of a sterile effusion. Six patients had recurrent effu sions ; in five, arthroscopy revealed partial tears of less than one-third of the prosthesis. Three patients who had recurrent effusions had PTFE particles in their synovial biopsies. One patient had an immediate post operative infection and to date has had salvage of the prosthesis and currently has a stable knee with full return to activities.

Based on the early results of this study, the GORE- TEX PTFE ACL prosthesis provided a satisfactory method of reconstruction for ACL deficient knees. Based on the evaluation used, 87% of the patients had satisfactory results. Problems associated with use of this prosthesis include partial or complete tears of the prosthesis and sterile effusions, possibly due to syno vial irritation from the PTFE particles. Appropriate placement of the graft, anterior and posterior notch plasty, and removal of sharp edges from the bony tunnels may help eliminate these problems.
Healed meniscal tears in unstable knees
Authors: Sommerlath Karola , Hamberg Per
Published: June 2007

Peripheral vertical ruptures of the medial (N = 24) and the lateral (N = 4) meniscus were repaired in 28 patients (mean age, 27 years). They all had an ACL lesion, combined in 26 cases with a MCL tear. These injuries were reconstructed or sutured during the same session as the meniscus repairs. Approximately 1 year later, meniscal healing was proven arthroscopically in 20 and the other 8 had no clinical signs of meniscal rerupture. All patients were reexamined between 6 to 8 years after the initial repair. Instrumented stability testing, the Lysholm knee function score and an activity score (Tegner) were used. The patients' subjective evalua tions were also recorded.

In spite of the previous reconstruction, all knees were quite unstable (mean +5 mm increased laxity compared with the uninjured side). At followup, 3 of the 28 re paired menisci (11%) had reruptured in connection with a minor trauma during sports or daily activity. The knee function score averaged 88 points, the activity level dropped 2 steps compared with activities before injury (from 7 to 5). Twenty patients were satisfied with the results, 5 partly satisfied, and 3 not satisfied.

A healed meniscal tear has a good chance of survival in an unstable knee. The most critical period of meniscal repair probably lies in the healing period just after surgery.
Factors affecting the region of most isometric femoral attachments
Authors: Hefzy Mohamed S. , Grood Edward S. , Noyes Frank R.
Published: June 2007

During flexion of the intact knee, we measured the changes in distance between possible tibial and femoral attachments of an intraarticular ACL substitute. The change in distance during motion was described by the difference between the longest and shortest distances measured. Using knees from eight cadaver donors, we studied the effects of varying tibial and femoral attach ment locations, applying anterior and posterior forces, and altering the range of flexion.

We found that altering the femoral attachment had a much larger effect than had altering the tibial attach ment. No femoral attachments were completely iso metric. Femoral attachments that produced the small est change in tibiofemoral distance, 2 mm and less, formed a band whose greatest width ranged from 3 to 5 mm. The axis of the 2 mm region was nearly proximal- distal in orientation and located near the center of the ACL's femoral insertion. Attachments located anterior to the axis moved away from the tibial attachment with flexion, whereas attachments located posterior to the axis moved toward the tibia.

The AP position of the tibial attachment affected the orientation of the 2 mm region. Moving the tibial attach ment posteriorly caused the proximal part of the region to move anterior, with little change in the location of the distal part of the region. Changing the applied joint force from anterior to posterior was similar to moving the tibial attachment posteriorly, but the effect was less pronounced. Increasing the range of flexion from 90° to 120° caused the 2 mm region to become narrower and changed its orientation.
Effects of fibrin sealant on incorporation of autograft and xenograft tendons within bone tunnels
Authors: Shoemaker Stephen C. , Rechl Hans , Campbell Patricia , Kram Harry B. , Sanchez Manuel
Published: June 2007

The anterior and posterior tibialis tendons in both hind- limbs of six adult dogs were rerouted through extraar ticular bone holes created in the distal tibial metaphysis. Xenograft tendons of comparable dimensions were used in an additional six dogs. Fibrin Sealant System (FSS) was applied to the bone tendon interface in the right legs, whereas the left legs were used as controls. The animals were sacrificed at 5, 9, and 28 days. Coronal sections of the distal tibias were studied his tologically and microangiographically. The autogenous tendons appeared to incorporate by means of fibrous ingrowth, whereas spicules of new bone in direct op position to the xenografts were observed at 28 days. FSS promoted organization and maturation of fibrous connective tissue surrounding both implants at early sacrifice but did not appreciably alter incorporation at 28 days.
Magnetic resonance imaging of Achilles tendon ruptures
Authors: Keene James S. , Lash Edward G. , Fisher David R. , De Smet Arthur A.
Published: June 2007

Preoperative magnetic resonance images of three acute Achilles tendon ruptures were correlated with the findings observed during surgical repair of the tendon. Specific comparisons were made regarding the condi tion (shredded, uniform, etc.) and orientation (ante- grade, retrograde, etc.) of the torn fibers, and the width of the diastasis (with and without ankle flexion) between the ends of the tendon. Magnetic resonance imaging (MRI) accurately assessed all of these parameters.
Arthroscopic treatment of transchondral talar dome fractures
Authors: Van Buecken Kent , Barrack Robert L. , Alexander A. Herbert , Ertl Janika P.
Published: June 2007

Fifteen cases of transchondral talar dome fractures treated arthroscopically at the Naval Hospital in Oak land, California, were reviewed. Roentgenograms and results from clinical examination were assessed pre operatively and at regular intervals postoperatively. Clinical followup of 18 months was obtained in all cases (range, 18 to 36 months; mean, 26 months). All lesions were treated with arthroscopic excision of fragments with abrasion and/or drilling of the remaining crater. There were nine excellent results, four good, one fair, and one poor. There were no complications. Results of arthroscopic treatment compare favorably to those of open arthrotomy.
Augmentation with the longitudinal patellar retinaculum in the repair of an anterior cruciate ligament rupture
Authors: Jonsson Torsten , Peterson Lars , Renström Per , Althoff BO , Myrhage Ragnar
Published: June 2007

Most authors advocate repair of the acutely ruptured ACL by augmentation or some form of primary recon struction. Strong autogenous tissues like the patellar and semitendinosus tendons and the iliotibial band are often used when augmentation is the surgical choice.

This paper describes a surgical procedure using a strip of the longitudinal patellar retinaculum as an aug mentation of the repaired ACL. The retinaculum adds stability and strength to the repaired ACL during the healing period. Moreover, the retinaculum may enhance the healing process of the ruptured ACL by revascular ization. It may also increase the stimulation of synovial tissue proliferation over the repaired ACL.

Twenty-eight patients have been clinically and objec tively evaluated at a mean follow-up time of 78 months (range, 63 to 94 months). The patients' own evaluation of their knee function was excellent or good in 86% (24 patients). Eighty-two percent (23 patients) could return to their preinjury activities at the same intensity level as before injury, whereas at an intermediate followup at 18 months only 64% (18 patients) had done so. Anterior tibial displacement was objectively evaluated at both followups by means of the anterior drawer test, with 20° to 30° and 90° of knee flexion, in a testing device. The operated knee usually showed a tendency to a slightly increased anterior displacement when com pared with the uninjured knee.

The repair of a ruptured ACL with an augmentation using the longitudinal patellar retinaculum has been shown to give good results after more than 5 years.
Overuse injuries in ultraendurance triathietes
Authors: O'Toole Mary L. , Hiller W. Douglas B. , Smith Richard A. , Sisk T. David
Published: June 2007

Overuse injuries represent the largest percentage of sports-related injuries requiring medical treatment. These injuries represent a substantial health issue for the millions of adults who have made physical activity an integral part of their lifestyle, but may be even more important to those pursuing ultraendurance exercise. The purposes of this study were to report the type and incidence of overuse injuries in ultraendurance triath letes and to relate training practices to injury occur rence. Data was gathered from the responses of 95 competitors (75 men, 20 women) in the 1986 Hawaii Ironman Triathlon who completed a training and medical history questionnaire. In this sample, virtually all (91 %) sustained at least one soft tissue, overuse injury during the previous year's training. The area of the body most frequently involved was the back, but the most common pattern was to have multiple areas involved. Because of the consistent combinations of injuries, mechanical abnormalities, such as diminished shock absorption, may have contributed to injury. Training habits were extremely variable and not directly related to either the incidence or type of injury.
Players' attitudes to mouthguards and prevalence of orofacial injuries in the 1987 U.S. Rugby Football Team
Authors: Chapman P.J.
Published: June 2007

This report shows that although 95.4% of players in the U.S. Rugby Team believed mouthguards provided local protection, only half wore a mouthguard. How ever, 90.9% of mouthguard wearers would not play without their mouthguard and 54.5% believed wearing mouthguards should be made compulsory in rugby football. Approximately one-third of the team had sus tained an orofacial injury that required treatment and none were wearing a mouthguard at the time of injury. These and other results are compared to an identical study of the 1984 Australian Rugby Team, the only previous such study reported.
Fluid and electrolyte balance during a cool weather marathon
Authors: Nelson Paul B. , Ellis David , Fu Freddie , Bloom Marie D. , O'Malley Jean
Published: June 2007

Changes in blood, serum, and urine parameters that are usually associated with fluid and electrolyte balance were studied in 45 volunteers who ran the 1987 Pitts burgh Marathon. There were 39 males and 6 females. The mean age was 39.3 years. Their mean fluid intake was 1650 cc and the mean finishing time was 4 hours and 1 minute. The race was run in the rain with a temperature of 46°F.

When the prerace and postrace values of the runners were compared, significant increases were noted in the serum sodium, potassium, blood urea nitrogen (BUN), creatinine, uric acid, creatine phosphokinase (CPK), protein, plasma renin, vasopressin, and urinary potas sium. Significant decreases were found in weight, blood pressure, and urinary sodium. No significant differences were noted in serum chloride, serum glucose, and hemoglobin/hematocrit. The mean weight loss of 1.9 kg was less than weight losses reported in marathons run under warmer conditions.
Graft force-setting technique in reconstruction of the anterior cruciate ligament
Authors: Hunter Robert E. , Lew William D. , Lewis Jack L. , Kowalczyk Curtis , Settle William
Published: June 2007

The objective of this work was to present a method for controlling the mechanical state of the knee during graft fixation in an ACL reconstruction; that is, adjusting the unloaded length of the graft at the time of fixation so that the force-carrying characteristics of the graft match that of the intact ACL, when the normal and recon structed knees are subjected to the same external load. To demonstrate the new method, an experimental knee testing system was used to measure ligament and graft forces with buckle transducers, as external loads were applied to five fresh knee specimens with a pneumatic load apparatus. ACL and collateral ligament force data were collected as anteriorly directed loads of 90 N (20 pounds) were applied at 0°, 30°, 60°, and 90° of flexion in the normal intact knee and the same knee following ACL excision. A composite graft was prepared, con sisting of distally based semitendinosus and gracilis autogenous tissue augmented with the Kennedy Liga ment Augmentation Device. Femoral fixation was ob tained using a fixation plug that was inserted through the lateral femoral condyle. With a 90 N anterior tibial load applied at 30° of flexion and a single buckle transducer measuring the total composite graft force, the graft length was varied using the fixation plug until the force matched that seen by the intact ACL under the same loading condition. The graft was then clamped in the fixation plug and the anterior load sequence at the four flexion angles was applied to this reconstructed knee state. Ligament and graft forces were measured and compared to the normal intact knee and cut ACL force data. The proposed force-setting method of ACL reconstruction resulted in graft forces that were closer to normal than when using current reconstruction meth ods based on isometry and pretension, and allowed better reproducibility of total graft forces among a series of knees.
Capsular ligaments of the shoulder
Authors: Ferrari Dudley A.
Published: June 2007

One hundred shoulders of 50 cadavers were dissected using the anterior approach. The normal appearance of the capsule, particularly the anterior superior, and the functions of the structures during passive motion were noted. There was a distinct capsular pattern with a Z formation which included the coracohumeral ligament and the superior, middle, and inferior glenohumeral ligaments. The middle and proximal capsular structures appeared to restrain external rotation. The coracohu meral ligament aided in restraint of external rotation at the lower range of abduction. The middle glenohumeral ligament was critical in restraining external rotation between 60° and 90° of abduction. It was readily identifiable except in a small percentage of individuals, who had a weak or absent ligament. The large capsular opening sometimes seen in shoulder repairs is due to an absent or attenuated middle glenohumeral ligament. Both the coracohumeral and middle glenohumeral lig aments were found to support the dependent arm.
The use of magnetic resonance imaging in exertional compartment syndromes
Authors: Amendola A. , Rorabeck C.H. , Vellett D. , Vezina W. , Rutt B. , Nott Linda
Published: June 2007

This prospective, double-blind study was carried out to assess the usefulness of magnetic resonance imaging (MRI) as a noninvasive method in the diagnosis of chronic compartment syndrome (CCS). As well, a new radiopharmaceutical known as methoxy isobutyl isoni trile that has been shown to be taken up by muscle in direct proportion to its blood flow was used to illustrate the possible pathophysiology of this syndrome.

Twenty patients with a history of chronic leg pain and possible diagnosis of CCS and five normal volunteers had preexercise and postexercise MRI, nuclear medi cine imaging, and static and dynamic slit catheter pres sure studies.

Nine patients had classic symptoms; only five of these nine had abnormal pressure studies. The other 11 patients had an element of pain at rest and had normal pressure studies. The nuclear blood flow studies were normal in all 25 legs tested in this study. Measurement of intrinsic MRI parameters T1 and T2 in the normal legs as well as in those with an atypical history showed a marked elevation with exercise and a gradual return to baseline postexercise that was similar to the pres sure curves. In the five patients with a clinical history and elevated pressures, four had abnormal MRI studies with failure of T1 to return to baseline values.

Although these results demonstrate the potential of MRI as a tool for noninvasively monitoring muscle sta tus, clinical history and examination remain important in the diagnosis of CCS. This study indicates that the pathophysiology of exertional compartment syndrome does not appear to be related to ischemia.
A nonparallel, nonisometric synthetic graft augmentation of a patellar tendon anterior cruciate ligament reconstruction
Authors: McCarthy Jack A. , Steadman J. Richard , Dunlap Janet , Shively Robert , Stonebrook Scott
Published: June 2007

The potential for a rigidly fixed synthetic graft placed in the over-the-top position to be stress shielding/stress sharing with the patellar tendon autograft was as sessed in a primate model. A patellar tendon autograft was placed anatomically and tensioned at 2 pounds for all of the groups. In the augmented animals, a 30 strand braided graft 10 cm in length of expanded polytetra fluoroethylene was tightened with the knee in full ex tension. After 6 months of unrestricted cage activity the animals were sacrificed and biomechanical testing performed. The augmented patellar tendon autografts demonstrated less laxity in extension as compared to the autografts alone. A minimal decrease in the load and stiffness to failure for the augmented groups as compared to the nonaugmented knees was noted. However, both the reconstruction groups had a signif icant decrease in the load to failure at 6 months (50% of the normal ACL).

In summary, this study demonstrated that a synthetic graft augmentation can be performed in the over-the- top position and minimize knee laxity, especially during terminal extension. With this technique, the laxity was minimized while the incorporation and strengthening of the biologic autograft occurred at a rate similar to the unaugmented reconstruction.
Injuries in intercollegiate rodeo athletes
Authors: Meyers Michael C. , Elledge Jerry R. , Sterling James C. , Tolson Homer
Published: June 2007

Collegiate rodeo athletes (N = 156) in the National Intercollegiate Rodeo Association (NIRA) Southern Re gion, were examined for injuries during a 7 month (10 rodeo) season from 1987 to 1988. Sixty-two athletes sustained a total of 138 acute injuries resulting from 3292 exposures. One hundred twenty-seven injuries (92% of total injuries) occurred in the roughstock and steer wrestling events, and 11 injuries (8%) occurred in the roping and female events. When calculating oppor tunity for injury, rodeo athletes face an 89% potential for injury per season. Ninety-one of the injuries incurred were upper body injuries; 47 were lower body injuries. A 6:1 exposure to injury ratio among roughstock events exemplifies the magnitude of injury potential in this sport, affecting 25% of roughstock competitors. Con tusions, strains, and concussions comprised 42%, 16%, and 11 % of the total injuries, respectively, whereas fractures and dislocations comprised only 5% of the total. Twenty-three percent of the injuries oc curred during the completion of an athlete's ride, with 21 % of injuries attributed to equipment mishaps. Fre quency of injury by performance, relation of seasonal participation and exposure to injury, orthotic care, use of conditioning programs, medication history, and need for enhanced sports medicine education in this sport are discussed.
Amateur boxing in Denmark
Authors: Schmidt-Olsen Søren , Jensen Søren Kaalund , Mortensen Vagner
Published: June 2007

A survey of all amateur boxing matches in Denmark was made during a 3 year period. Data was gathered on means by which bouts were ended by the referee or attending physician, such as knock outs or blows to the head. A total of 5272 matches were fought: 3240 were senior matches (over age 19) and 2032 were junior matches (ages 17 to 19). Prophylactic interven tion—unlimited length of hand bandage, voluntary use of boxing helmets, and heavier gloves for boxers > 149 pounds-did not affect the frequency of matches being stopped because of knock outs or blows to the head.
Flexibility comparisons of junior elite tennis players to other athletes
Authors: Chandler T. Jeff , Kibler W. Ben , Uhl Tim L. , Wooten Beven , Kiser Ann , Stone Elizabeth
Published: June 2007

Flexibility measurements were obtained in 86 junior elite tennis players and compared to the flexibility meas urements of 139 athletes involved in other sports. The measurements obtained included sit and reach flexibil ity, quadricep flexibility, hamstring flexibility, gastroc nemius flexibility, shoulder internal rotation, and shoul der external rotation. All measurements except sit and reach flexibility were obtained goniometrically. Tennis players were significantly tighter in sit and reach flexi bility, dominant shoulder internal rotation, and nondom inant shoulder internal rotation. They were significantly more flexible in dominant shoulder external rotation and nondominant shoulder external rotation. The flexibility differences found in tennis players suggest adaptations to the musculoskeletal demands of their sport. These results suggest that a sport-specific flexibility program may be necessary for junior elite tennis players in order to promote maximum performance and help prevent flexibility-related injuries.
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.
Living with artificial grass: A knowledge update
Authors: Skovron Mary Louise , Levy I. Martin , Agel Julie
Published: June 2007

Part 2 of our study evaluated the effect of artificial grass on the athletes that play on it. In this section we have reviewed the epidemiological studies that have evalu ated the influence that artificial grass has on the fre quency and site of injury to American football players. From this review we have concluded that play and practice on an artificial surface is probably responsible for an increase in the relative risk of injury to the lower extremity of the participants. However, it is evident that more well controlled studies are necessary to com pletely clarify this issue.
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.
Postarthroscopy analgesia with bupivacaine
Authors: Henderson Richard C. , Campion Edmund R. , DeMasi Ralph A. , Taft Timothy N.
Published: June 2007

The analgesic effect of intraarticular bupivacaine in jected at the conclusion of knee arthroscopy done under general anesthesia was investigated in a pro spective, randomized, and blinded fashion. Pain scores, the use of analgesic medications, crutch use, weight bearing, activity level, and difficulty sleeping the night after surgery were all unaffected by the use of bupiva caine. The apparent lack of effect is most likely due to rapid clearance from the knee, leaving only a transient, 1 to 2 hours of potential benefit. In this study, the patients were already quite comfortable during this time period due to the routine use of intraoperative narcotics. The preoperative level of knee discomfort was found to be a major determinant of postoperative discomfort. Other much less important factors were synovial and chondral shaving, sex of the patient, and experience of the surgeon.
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.
Anterior knee motion analysis
Authors: Stäubli Hans-Ulrich , Jakob Roland P.
Published: June 2007

Sixteen patients with a clinically diagnosed chronic ACL deficient knee on one side and a contralateral ACL intact knee were evaluated by arthrometry and simul taneous radiography after epidural anesthesia was in duced. The posterior cruciate ligament was intact in all knees. This paper reports only the anterior position of the tibia at the 89 N anterior force level of the KT-1000 arthrometer (as read from the dial) and the anterior tibial position recorded simultaneously by radiography at the 89 N dial tone. A 3 mm difference in anterior tibial position between the two knees of the same patient was considered diagnostic for ACL deficiency. Arthro metrically, 13 of the 16 patients were diagnosed accu rately ; radiographically, 13 of the 16 met the criterion. Moderately high significant positive correlation of paired values was obtained in ACL deficient knees by the two methods (correlation, 0.58 and two-tail probability, 0.02). In ACL intact knees there was no correlation of paired values (correlation, 0.01 and two-tail probability, 0.98). We found no numerical equivalency between the measurements obtained by the KT-1000 and simulta neous radiography. Neither did we find an apparent pattern to the differences, or formula we could use to interpolate findings of anterior tibial position from one measurement system to the other. We conclude that an examiner can substantiate a clinical diagnosis of chronic ACL deficiency with both methods. Arthrometry alone may be used to repeatedly follow conservatively treated ACL deficient knees without exposing the pa tient to radiation. Radiographs obtained under known anterior force levels provide a retrievable record to document the exact tibial position in relation to the femur.
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.
Abdominal musculature abnormalities as a cause of groin pain in athletes
Authors: Taylor Dean C. , Meyers William C. , Moylan Joseph A. , Lohnes John , Bassett Frank H. , Garrett William E.
Published: June 2007

There has been increasing interest within the European sports medicine community regarding the etiology and treatment of groin pain in the athlete. Groin pain is most commonly caused by musculotendinous strains of the adductors and other muscles crossing the hip joint, but may also be related to abdominal wall abnormalities. Cases may be termed "pubalgia" if physical examination does not reveal inguinal hernia and there is an absence of other etiology for groin pain. We present nine cases of patients who underwent herniorrhaphies for groin pain. Two patients had groin pain without evidence of a hernia preoperatively (pubalgia). In the remaining seven patients we determined the presence of a hernia by physical examination. At operation, eight patients were found to have inguinal hernias. One patient had no hernia but had partial avulsion of the internal oblique fibers from their insertion at the pubic tubercle. The average interval from operation to return to full activity was 11 weeks. All patients returned to full activity within 3 months of surgery. One patient had persistent symp toms of mild incisional tenderness, but otherwise there were no recurrences, complications, or persistence of symptoms. Abnormalities of the abdominal wall, includ ing inguinal hernias and microscopic tears or avulsions of the internal oblique muscle, can be an overlooked source of groin pain in the athlete. Operative treatment of this condition with herniorrhaphy can return the athlete to his sport within 3 months.