bluuebunny/crossref_metadata_2025 huggingface dataset:
Gamma Irradiation: Effects on Biomechanical Properties of Human Bone-Patellar Tendon-Bone Allografts
Authors: Fideler Bradley M. , Vangsness C. Thomas , Bin Lu  , Orlando Carlo , Moore Tilman
Published: June 2007

Sixty 10-mm bone-patellar tendon-bone allografts from young human donors were placed into four test groups, a control fresh-frozen group and three fresh-frozen ir radiated groups. The irradiated groups were exposed to 2.0, 3.0, or 4.0 Mrad of gamma irradiation. The speci mens were tested to tensile failure. The initial biome chanical strength of fresh-frozen allografts was reduced up to 15% when compared with fresh-frozen controls after 2.0 Mrad of irradiation. Maximum force, strain en ergy, modulus, and maximum stress demonstrated a statistically significant reduction after 2.0 Mrad of irra diation ( P< 0.01). Stiffness, elongation, and strain were reduced but not with statistical significance. A 10% to 24% and 19% to 46% reduction in all biomechanical properties were found after 3.0 ( P < 0.005) and 4.0 ( P < 0.0005) Mrad of irradiation, respectively. After irra diation with a 4.0 Mrad dose, the ultimate load was be low that of reported values for the human anterior cru ciate ligament. It is clinically important to observe and document changes in human ligaments that result from currently used doses of gamma irradiation. The results from this study provide important information regarding the initial biomechanical properties of fresh-frozen hu man bone-patellar tendon-bone allografts after bacte rial sterilization with gamma irradiation. The current ac cepted dose for sterilization is between 1.5 and 2.5 Mrad. There appeared to be a dose-dependent effect of irradiation on all the biomechanical parameters studied. Four of seven parameters were found to be reduced after 2.0 Mrad of irradiation. Reductions were found in all parameters after 3.0 and 4.0 Mrad of irradiation.
Reflex Sympathetic Dystrophy of the Knee
Authors: O'Brien Stephen J. , Ngeow Jeffrey , Gibney Mary Ann , Warren Russell F. , Fealy Stephen
Published: June 2007

Sixty patients with the diagnosis of reflex sympathetic dystrophy of the knee were evaluated retrospectively at our institution. The average followup was 2 years. Fifty- five (92%) patients treated with outpatient sympathetic blockade had resolution of the symptoms attributed to reflex sympathetic dystrophy. The time from onset of symptoms to initiation of treatment did not affect the ultimate outcome. The prognosis was most closely re lated to the presence or absence of an anatomic lesion that would continue to act as a painful stimulus. Eighty- one percent (29 of 36) of patients who had a significant anatomic lesion or surgical correction of a lesion had a complete resolution of their knee symptoms. However, only 21 % (5 of 24) of patients with a persistent anatomic lesion in the knee had complete resolution. Fourteen patients required preliminary sympathetic blockade therapy before the underlying cause could be identified. This study emphasizes the need for establishing a pre cise diagnosis before contemplating any surgery of the knee, including arthroscopy. Arthroscopic procedures were the most common event precipitating reflex sym pathetic dystrophy in this study.
Critical Analysis of Knee Ligament Rating Systems
Authors: Sgaglione Nicholas A. , Del Pizzo Wilson , Fox James M. , Friedman Marc J.
Published: June 2007

Sixty-five patients who consecutively underwent ante rior cruciate ligament reconstruction were studied using four individual, categoric, knee score rating systems. Different results were noted at followup (mean, 35 months; range, 24 to 58) depending on the rating method used. All patients were graded using the Hos pital for Special Surgery, Lysholm, Tegner activity, and Cincinnati Knee Ligament rating systems. The Cincin nati Knee Ligament rating individual scores were noted to be lower than the Hospital for Special Surgery and Lysholm scores for subjective and objective outcome assessment. The Hospital for Special Surgery and Lys holm scores did not correlate highly with the Cincinnati Knee Ligament rating final rating, but they did correlate with each other. The use of ligament rating scores tended to inflate results, particularly when raw scores were converted to overall categoric ratings (e.g., ex cellent, good). The Cincinnati Knee Ligament rating system correlates more highly with individual grading and most precisely defines outcome in athletically ac tive patients. Sources of error may be introduced by a disproportionate combination of unrelated scores or by overrating low-activity-level individuals who avoid stressing their knees. Avoidance of data generalization remains the optimal method for studying anterior cru ciate ligament surgery outcome.
Simulated Lateral Ankle Ligamentous Injury
Authors: Marcus Hollis J. , Dale Blasier R. , Flahiff Charlene M.
Published: June 2007

The effect of simulated ankle ligamentous injury on ankle-subtalar joint complex laxity was studied. Thirty- six intact ankles were loaded in inversion-eversion and anterior-posterior directions. Motions of the talus and calcaneus were measured with respect to the tibia. Ankles were tested at neutral, 15° of dorsiflexion, and 15° of plantar flexion. In all the specimens the anterior talofibular ligament was sectioned and then the calca neofibular ligament was sectioned; testing was then re peated. With sectioning of the anterior talofibular liga ment, motion increased primarily in dorsiflexion with both anterior-posterior and inversion-eversion loading. This increase was primarily caused by a large increase in subtalar motion. Additional sectioning of the calca neofibular ligament produced little change in ankle sub talar joint motion except in dorsiflexion. Clinically, these findings show that if an anterior-posterior drawer test shows less laxity in dorsiflexion than in neutral and greater laxity than the contralateral asymptomatic side, then an isolated anterior talofibular ligamentous tear ex ists. Similarly, laxity in 15° of dorsiflexion and in neutral suggests calcaneofibular ligament disruption. During inversion-eversion loading, the increase in ankle- subtalar joint complex rotation with calcaneofibular liga ment sectioning occurred primarily in the ankle joint, implying that the calcaneofibular ligament constrains the talus through the calcaneus. Therefore, a talar tilt on stress radiographs demonstrates a torn calcaneofibular ligament.
Injury Patterns in Recreational Rock Climbers
Authors: Rooks Michael D. , Johnston Richard B. , Ensor Cindy D. , Mclntosh Bobbi , James Susan
Published: June 2007

We studied 39 recreational rock climbers to determine the incidence and pattern of injuries sustained in the sport at their level. Eleven climbers (26%), who climbed beyond the sport level, had sustained a major injury from a fall. Thirty-five climbers (89%) sustained at least one significant injury. Fifty percent of the injuries in volved the hand or wrist. Only seven climbers (19%) had evidence of a digital pulley injury (climber's finger). Four climbers (11%) had evidence of a carpal tunnel syn drome. Twenty climbers (50%) had tendinitis in an up per extremity on physical examination.
Comparison Between Magnetic Resonance imaging Findings and Knee Stability: Measurements After Anterior Cruciate Ligament Repair With and Without Augmentation
Authors: Grøntvedt Torbjørn , Engebretsen Lars , Rossvoll Ivar , Smevik Olaug , Nilsen Gunnar
Published: June 2007

We compared magnetic resonance imaging findings with knee stability measurements in a group of 52 pa tients 5 to 7 years after repair of an acute anterior cru ciate ligament rupture. The patients underwent one of three surgical procedures: nonaugmented repair using the Palmer technique, repair with synthetic augmenta tion, and repair with biologic augmentation. The appear ances of the menisci, subchondral bone, and cartilage were also assessed. Of the patients with clinically stable knees in the nonaugmented repair group, the repaired ligament appeared to be present and intact in 54% (7 of 13) of the patients. In the group with the repair aug mented with the ligament augmentation device, 33% (4 of 12) demonstrated repair integrity, whereas in the group with patellar tendon augmentation of the repair, 82% (14 of 17) of the patients with clinically stable knees had intact ligaments on magnetic resonance imaging. Twelve patients had new and complete ruptures of one of the menisci, nine of which occurred in unstable knees. Thirteen patients had subcortical bone changes in the femoral condyles. Eight of these knees had major degenerative cartilage changes overlying the bone changes. Magnetic resonance imaging signals in the repaired ligament augmented with the patellar tendon were highly predictive of clinical stability, but the integ rity of the nonaugmented and ligament augmentation device-augmented anterior cruciate ligament repairs did not closely correlate with the clinical findings.
The Human Posterior Cruciate Ligament Complex: An Interdisciplinary Study
Authors: Harner Christopher D. , Xerogeanes John W. , Livesay Glen A. , Carlin Gregory J. , Smith Brian A. , Kusayama Takeshi , Kashiwaguchi Shinji , Woo Savio L.-Y.
Published: June 2007

To study the structural and functional properties of the human posterior cruciate ligament complex, we meas ured the cross-sectional shape and area of the anterior cruciate, posterior cruciate, and meniscofemoral liga ments in eight cadaveric knees. The posterior cruciate ligament increased in cross-sectional area from tibia to femur, and the anterior cruciate ligament area de creased from tibia to femur. The meniscofemoral liga ments did not change shape in their course from the lateral meniscus to their femoral insertions. The pos terior cruciate ligament cross-sectional area was ap proximately 50% and 20% greater than that of the an terior cruciate ligament at the femur and tibia, respectively. The meniscofemoral ligaments averaged approximately 22% of the entire cross-sectional area of the posterior cruciate ligament. The insertion sites of the anterior and posterior cruciate ligaments were evalu ated. The insertion sites of the anterior and posterior cruciate ligaments were 300% to 500% larger than the cross-section of their respective midsubstances. We determined, through transmission electron microscopy, fibril size within the anterior and posterior cruciate liga ment complex from the femur to the tibia. The posterior cruciate ligament becomes increasingly larger from the tibial to the femoral insertions, and the anterior cruciate ligament becomes smaller toward the femoral insertion. We evaluated the biomechanical properties of the femur-posterior cruciate ligament-tibia complex using 14 additional human cadaveric knees. The posterior cruciate ligament was divided into two functional com ponents : the anterolateral, which is taut in knee flexion, and the posteromedial, which is taut in knee extension. The anterolateral component had a significantly greater linear stiffness and ultimate load than both the postero medial component and meniscofemoral ligaments. The anterolateral component and the meniscofemoral liga ments displayed similar elastic moduli, which were both significantly greater than that of the posteromedial com ponent.
The Effect of the Mandatory Use of Face Masks on Facial Lacerations and Head and Neck Injuries in Ice Hockey
Authors: LaPrade Robert F. , Burnett Quinter M. , Zarzour Robert , Moss Robert
Published: June 2007

A 4-year prospective review of lost-time injuries and fa cial lacerations was performed for a National Collegiate Athletic Association Division I, intercollegiate ice hockey team. The total injury exposure time consisted of 798.5 practice hours and 163 games. There were 16 facial lacerations, with an incidence of 14.9 per 1000 player-game hours and 0.1 per 1000 player-practice hours; both incidences were found to be less than in previous comparable studies where the use of face masks was not mandatory. In addition, there were eight lost-time head and neck injuries that accounted for 6.3% of all lost-time injuries. We found that the mandatory use of face masks in intercollegiate ice hockey results in a reduction in facial lacerations and no increase in overall head and neck injuries.
The Biceps Femoris Muscle Complex at the Knee
Authors: Terry Glenn C. , LaPrade Robert F.
Published: June 2007

We dissected 30 cadaveric knees to provide a detailed anatomic description of the biceps femoris muscle complex at the knee. The main components of the long head of the muscle are a reflected arm, a direct arm, an anterior arm, and a lateral and an anterior aponeurosis. The main components of the short head of the biceps femoris muscle are a proximal attachment to the long head's tendon, a capsular arm, a confluens of the biceps and the capsuloosseous layer of the iliotibial tract, a direct arm, an anterior arm, and a lateral apo neurosis. We examined 82 consecutive, acutely in jured knees with clinical signs of anterolateral-antero medial rotatory instability for the incidence and anatomic location of injuries to the biceps femoris mus cle. Injuries to components of that muscle were iden tified in 59 (72%) of these knees; 29 knees (35.4%) had multiple components injured. There were 3 injuries to the long head of the biceps femoris muscle (all in the reflected arm) and 89 to the short head. A statistically significant correlation (P = 0.01) was found between increased anterior translation with the knee at 25° of flexion as demonstrated by the Lachman test and in jury to the biceps-capsuloosseous iliotibial tract conflu ens. Additionally, adduction laxity at 30° of flexion cor related with a Segond fracture ( P = 0.04). These data establish, in part, the relationship of the biceps femoris complex injury to anterior translation instability.
Factors Associated with Wrist Pain in the Young Gymnast
Authors: DiFiori John P. , Puffer James C. , Mandelbaum Bert R. , Mar Sabrina
Published: June 2007

We conducted a cross-sectional survey of 52 nonelite gymnasts (32 girls, 20 boys; average age, 11.8 years) to assess their history of training and wrist pain within the last 6 months. An intensity index was created using the number of training hours per week and the athletes' skill levels. Wrist pain was prevalent in 38 (73%) of the gymnasts. Gymnasts with wrist pain were older (12.6 years versus 9.7 years; P = 0.0002), trained more hours per week (13.5 versus 7.7; P = 0.0002), trained at a higher skill level ( P = 0.01), and began training at an older age (7.0 years versus 5.1 years; P = 0.006). Analysis of intensity versus age suggested that a threshold of training intensity may be important in the development of wrist pain. Logistical regression found these factors to be independently associated with wrist pain: intensity ( P = 0.036), age >10 years ( P = 0.018), age <14 years (P = 0.016), and the age of initiation of training ( P = 0.020). This study demon strates that wrist pain is a common problem among nonelite young gymnasts. Training intensity, relative to the age of the participant and the age when training was initiated, appears to be an important determinant of the development of wrist pain in this population.
Pathogenesis of Sports-Related Spondylolisthesis in Adolescents
Authors: Ikata Takaaki , Miyake Ryoji , Katoh Shinsuke , Morita Tetsuki , Murase Masaaki
Published: June 2007

We reviewed radiographs and magnetic resonance im ages of 77 young athletes with spondylolysis and spon dylolisthesis (more than 5% vertebral slip) (slip group). The results were compared with similar studies in 88 patients with spondylolysis only (nonslip group). End- plate lesions were found in all patients in the slip group and in 60 (68%) of those in the nonslip group. Slippage between the osseous and cartilaginous endplates was identified in the T1-weighted sagittal magnetic reso nance images and categorized according to the type of slippage: total slip of L-5 or S-1, partial slip of L-5 or S-1, or a combination of these (mixed type). In a study of 31 patients whose slippages progressed, no slip page was associated with the early stage of a pars interarticularis defect. Most vertebral slippages devel oped or progressed in the cartilaginous or apophyseal stage of the lumbar skeletal age. Wedging of the L-5 vertebral body and rounding of the sacrum progressed as the slippage developed; these did not occur in the nonslip group. These results indicate that the ad vanced stage of a pars interarticularis defect in an immature spine is a risk factor for spondylolisthesis. The deformities of the lumbosacral spine are thought to be the secondary changes caused by vertebral slippage.
The Long-Term Biomechanical and Viscoelastic Performance of Repairing Anterior Cruciate Ligament after Hemitransection Injury in a Goat Model
Authors: Ng Gabriel Y. F. , Oakes Barry W. , McLean lain D. , Deacon Owen W. , Lampard Douglas
Published: June 2007

To test the healing of the partially torn anterior cruciate ligament, we transected the posterolateral bundle in 11 adult female goats and tested the ligaments at 12, 24, and 52 weeks and 3 years after surgery. As early as 12 weeks after surgery translucent fibrous tissue covered the wound. The differences in anteroposterior laxity between right and left knees measured at 45° and 90° of flexion were not significantly different at each period. Results of Instron testing of the posterolateral bundle revealed the normalized changes in load-relaxation and Young's modulus were not significantly different at each period, but the ultimate tensile strength and stiff ness at 3 years were significantly higher than at 12 weeks ( P < 0.05). Failure started at the repair site for the 12-week group, but at 24 and 52 weeks the failure occurred throughout the ligament. At 3 years, the spec imens failed with bony avulsion, indicating the repaired tissue was not the weakest link of the bone-ligament- bone complex. This study shows that under favorable conditions, partial anterior cruciate ligament injuries are capable of repair. What is more important, the high ultimate tensile strength and stiffness of the 3-year repaired tissue indicate full structural repair of such an artificial transection injury may be possible.
Hamstring Muscle Injuries Among Water Skiers
Authors: Sallay Peter I. , Friedman Robert L. , Coogan Philip G. , Garrett William E.
Published: June 2007

Water skiing is associated with severe injuries to the proximal hamstring muscles. We wanted to define the mechanism of injury, describe the associated patho logic changes, determine the functional limitations of patients, and suggest measures to prevent injury. Twelve patients with water skiing-related hamstring injuries were included. Six patients were experienced skiers and six were novices. The mechanism of injury was identical in five of six novice skiers. Each sus tained the injury while attempting to get up on one or two skis from a submerged position. In contrast, the expert skiers all sustained injury secondary to a fall while skiing. Physical examination documented evi dence of complete or partial avulsion of the proximal hamstring muscle origins in all patients. In addition, six patients had magnetic resonance imaging or computed tomography scans that confirmed the location and ex tent of the tear. Convalescence ranged from 3 months to 1.5 years before the patient could return to vigorous activities. Seven patients (58%) returned to most of their preinjury sports, albeit at a lower level. Five pa tients (42%), all with complete disruptions, were unable to run or participate in sports requiring agility. Two of these patients required delayed surgical repairs be cause of persistent functional limitations.
Arthroscopic Versus Open Reconstruction of the Shoulder in Patients with Isolated Bankart Lesions
Authors: Guanche Carlos A. , Quick Donald C. , Sodergren Kristan M. , Buss Daniel D.
Published: June 2007

We compared open and arthroscopic stabilizations of true Bankart lesions in patients with traumatic, unidi rectional anterior glenohumeral dislocations. The 27 patients were men (age range, 18 to 56 years) who were involved in recreational sports. One group (15 patients) had elected an arthroscopic Bankart repair; the other group (12 patients) had chosen open stabili zation with a standard deltopectoral approach. Patients were followed up 17 to 42 months after surgery by examination, radiographs, and interviews. In the open repair group, 1 of the 12 patients experienced a sub luxation in the follow-up period, but no patients had dislocations or reoperations. In the arthroscopic group, 5 of 15 patients had experienced subluxation or dislo cation ; of these 5 patients, 2 underwent reoperation. The arthroscopic group had significantly worse results in satisfaction, stability, apprehension, and loss of for ward flexion in the operated limb. In summary, the arthroscopic procedure did not significantly improve function; instead, it produced an increased failure rate compared with the open procedure. Therefore, we be lieve that open stabilization remains the procedure of choice for patients with true Bankart lesions.
Long-Term Prognosis of Isolated Partial Medial Collateral Ligament Ruptures
Authors: Lundberg Magnus , Messner Karola
Published: June 2007

We prospectively observed 38 patients with nonopera tively treated isolated partial ruptures of the knee me dial collateral ligament at 3 months, 4 years, and 10 years after the initial trauma using clinical and radio graphic examinations. The initial diagnoses were based on clinical and arthroscopic examinations. Three months after injury, 28 patients (74%) had re gained nearly normal knee function and muscle strength, and 75% of these patients could perform at their preinjury activity level (competitive team sports). Five patients (13%) had increased valgus laxity (grade I) in the injured knee. After 4 years, the patients had a median Lysholm score of 100 (range, 64 to 100). Thir ty-three patients (87%) had normal knee function dur ing strenuous activities. Repeat injuries to the medial collateral ligament occurred in two patients (5%), and another two patients sustained cruciate ligament inju ries during the follow-up period. After 10 years, the Lysholm score (median, 95; range, 73 to 100) was lower compared with the 4-year score (P < 0.03), but the patients still performed on a similarly high activity level. Five patients (13%) had distinct signs of begin ning osteoarthritis (Fairbank's signs) on radiographs, but none had joint space reduction.
Neuromuscular Adaptations in Isokinetic, Isotonic, and Agility Training Programs
Authors: Wojtys Edward M. , Huston Laura J. , Taylor Paul D. , Bastian Steven D.
Published: June 2007

Weight training is an integral part of most athletic con ditioning programs; yet, the effect of these programs on neuromuscular function remains unclear. To exam ine the neuromuscular effects of training and condition ing at the knee joint, 32 volunteers (16 men and 16 women; average age, 25.4 years) were placed into one of four groups: isokinetic, isotonic, agility, or control. Each group trained 3 days per week for 6 weeks. The knee function of all participants was evaluated just before and after the 6-week training period. The agility- trained group significantly improved the spinal reflex times of the lateral and medial quadriceps muscles in response to anterior tibial translation. The cortical re sponse time of the agility group also significantly im proved in the gastrocnemius, medial hamstring, and the lateral quadriceps muscles. Interestingly, the corti cal response time of the medial hamstring and the medial quadriceps muscles in the isokinetic group slowed significantly, by 39.1 and 32.4 msec, respec tively, after 6 weeks of training. Isotonic and isokinetic strength training of the lower extremities do not appear to improve muscle reaction time to anterior tibial trans lation, whereas agility exercises potentially improve this parameter.
The Use of Cold Therapy in the Postoperative Management of Patients Undergoing Arthroscopic Anterior Cruciate Ligament Reconstruction
Authors: Edwards Dennis J. , Rimmer Martin , Keene Greg C. R.
Published: June 2007

In this prospective, randomized study we assessed the use of cold therapy after arthroscopic anterior cruciate ligament reconstruction. Seventy-one patients were randomly allocated, without the knowledge of the sin gle surgeon, to one of three groups: Group I had an ice water-filled CryoCuff fitted in the operating theater after surgery, Group II had room temperature water in the CryoCuff, and Group III patients had no CryoCuff. Pa tients were well matched for age, sex, and associated surgery. An independent observer measured blood loss, analgesic use, range of motion, and visual analog pain scores postoperatively. There were no differences between any of the three groups regarding the vari ables measured. The use of cold therapy devices as an adjunct to the postoperative management of these pa tients must be questioned.
Radiographic Changes in the Knee After Meniscal Transplantation
Authors: Edwards Dennis J. , Whittle Simon L. , Nissen Michael J. , Cohen Brian , Oakeshott Roger D. , Keene Gregory C. R.
Published: June 2007

Meniscal transplantation has been suggested as an alternative to total meniscectomy, which is now known to lead to long-term osteoarthritic degeneration of the knee joint. To evaluate the success of meniscal trans plantation, we divided 28 sheep knees into 4 groups: total meniscectomy, allograft, autograft, and control. After a mean postoperative time of 21.4 months, we radiographed the excised knee joints in a loaded state and graded the radiographs for osteoarthritic changes. The knees with meniscectomies, allografts, and au tografts showed significantly more degenerative changes than the control knees. However, there were no statistically significant differences between these three groups. The results of this study suggest that meniscal allograft transplantation does not protect the knee against degenerative changes.
Fractures of the Distal Shaft of the Fifth Metatarsal
Authors: O'Malley Martin J. , Hamilton William G. , Munyak John
Published: June 2007

We retrospectively reviewed the office records of the senior author—which include two national ballet com panies—and identified 35 dancers who sustained dis tal shaft fractures of the fifth metatarsal. The usual fracture pattern is a spiral, oblique fracture starting distal-lateral and running proximal-medial. Treatment consisted of open reduction and internal fixation for 2 patients, closed reduction and percutaneus fixation for 2 patients, short leg weightbearing cast for 7 patients, and an elastic wrap and treatment of symptoms for 24 patients. Patients with marked displacement of the fracture underwent internal fixation early in the study period; but more recent treatment emphasized nonop erative means, even for displaced fractures. The aver age time to pain free walking was 6.1 weeks (range, 0 to 16); return to barre exercises, 11.6 weeks (range, 4 to 48); and return to performance, 19 weeks (range, 6 to 52). There was one delayed union (7 months) and one refracture (2 months) that subsequently healed. All patients returned to professional performance without limitation and no patient reported pain with perfor mance at followup. Spiral fractures of the distal shaft of the fifth metatarsal are common injuries and can usu ally be treated nonoperatively for these high perfor mance athletes without long-term functional sequelae.
Posterior Instability of the Glenohumeral Joint
Authors: Hawkins Richard J. , Janda David H.
Published: June 2007

Seventeen patients underwent posterior capsulotendi nous tensioning procedures to eliminate recurrent pos terior glenohumeral instability. Fourteen patients were evaluated an average of 44 months (range, 18 to 98) after surgery. The average patient age was 27 years. Before surgery, all patients were unable to perform their activities of daily living, occupational activities, and athletic activities. Preoperatively, the average pain rating score on a visual analog scale was 5 of 10 at rest and 9 of 10 with activities. Six patients had previous anterior reconstructions. After surgery, the average range of motion was 174° of forward elevation and 69° of external rotation; internal rotation was to the thumb level of T-8. No patient had a recurrence of posterior instability. After surgery, the average pain rating score was 2 of 10 at rest and 4 of 10 with activities. All patients improved after their operations, but four pa tients were minimally disabled from activities of daily living; six patients experienced shoulder fatigue at work; and four patients had difficulty with sports activ ities. Overall, 13 of the 14 patients were satisfied with their surgical procedures and their outcomes.
Shoulder Range of Motion in Elite Tennis Players
Authors: Kibler W. Ben , Chandler T. Jeff , Livingston Beven P. , Roetert E. Paul
Published: June 2007

We studied glenohumeral rotational range of motion in 39 members of the United States Tennis Association National Tennis Team and touring professional pro gram. We took goniometric measurements of internal and external rotation of dominant and nondominant shoulders at the glenohumeral joint with the humerus at 90° of abduction. We categorized the tennis players by age and by years of tournament play. Results were analyzed by total rotation, internal rotation, external rotation, and dominant-to-nondominant shoulder differ ences. In our results, dominant internal rotation of the shoulder declined and the difference between domi nant and nondominant internal rotation increased with both age and years of tournament play. Men and women tennis players showed the same degree of deficits in range of motion. Significant analysis of vari ance statistics were calculated for dominant internal rotation with years of total play, dominant total rotation with years of total play, and nondominant total rotation with age. Moderate negative correlations were found between dominant internal rotation and years of total play and dominant total rotation and years of total play. These results indicate a loss of internal rotation that seems progressive with longer periods of play. This loss of internal rotation of the shoulder is an absolute loss of motion because total rotation also decreases. Early detection and a corrective training program should be considered because adaptations may result in deleterious biomechanics affecting both perfor mance and risk of injury.
A Biomechanical Analysis of Rotator Cuff Deficiency in a Cadaveric Model
Authors: Thompson William O. , Debski Richard E. , Boardman N. Douglas , Taskiran Emin , Warner Jon J. P. , Fu Freddie H. , Woo Savio L.-Y.
Published: June 2007

We conducted this cadaveric study to define a biome chanical rationale for rotator cuff function in several deficiency states. A dynamic shoulder testing appara tus was used to examine change in middle deltoid muscle force and humeral translation associated with simulated rotator cuff tendon paralyses and various sizes of rotator cuff tears. Supraspinatus paralysis re sulted in a significant increase (101 %) in the middle deltoid force required to initiate abduction. This in crease diminished to only 12% for full glenohumeral abduction. The glenohumeral joint maintained ball- and-socket kinematics during glenohumeral abduction in the scapular plane with an intact rotator cuff. No significant alterations in humeral translation occurred with a simulated supraspinatus paralysis, nor with 1-, 3-, and 5-cm rotator cuff tears, provided the infraspi natus tendon was functional. Global tears resulted in an inability to elevate beyond 25° of glenohumeral abduction despite a threefold increase in middle deltoid force. These results validated the importance of the supraspinatus tendon during the initiation of abduction. Glenohumeral joint motion was not affected when the "transverse force couple" (subscapularis, infraspina tus, and teres minor tendons) remained intact. Signifi cant changes in glenohumeral joint motion occurred only if paralysis or anatomic deficiency violated this force couple. Finally, this model confirmed that rotator cuff disease treatment must address function in addi tion to anatomy.
Primary Repair for Posterior Cruciate Ligament Injuries
Authors: Richter Marcus , Kiefer Hartmuth , Hehl Gerhard , Kinzl Lothar
Published: June 2007

We reviewed 53 of 58 patients who had primary repairs of posterior cruciate ligament injuries between 1981 and 1988. Sixteen patients had isolated posterior cru ciate ligament ruptures, 16 had complex injuries with capsular and collateral ligament involvement, and 21 had additional anterior cruciate ligament ruptures. For ty-six patients were treated by transosseous multiple- loop sutures and seven with bony avulsions by screw osteosynthesis. The mean follow-up time was 7.5 years (range, 3 to 12). All patients were examined subjectively (questionnaire) and objectively (clinical ex amination, KT-1000 arthrometer, functional testing, ra diographs, and Cybex II isokinetic strength analysis). The results were graded according to the International Knee Documentation Committee evaluation form and the Lysholm score. The average Lysholm score was 82.4 (range, 40 to 100). Thirty-eight patients returned to their preinjury activities at the same intensity level. The patients' subjective assessments were normal or nearly normal in 35 patients. The posterior drawer test was negative or 1 + in 46 patients. Cybex isokinetic strength analysis revealed a decrease in quadriceps muscle strength of the involved limb by 10.5% (P < 0.01). Our data suggest that primary repair of posterior cruciate ligament ruptures provides good results after 8 years in approximately two thirds of the patients. Distal ligamentous ruptures, lack of athletic activity, and tem porary olecranization correlated with poor results. Bony avulsions, midsubstance or proximal ruptures, and athletic activity correlated with good results.
Long-Term Followup of the Untreated Isolated Posterior Cruciate Ligament-Deficient Knee
Authors: Boynton Melbourne D. , Tietjens Barry R.
Published: June 2007

We evaluated 38 subjects with isolated posterior cru ciate ligament-deficient knees at a mean of 13.4 years (range, 5 to 38) after injury to study the occurrence of symptoms, disabilities, and articular degeneration. Each subject completed a standardized questionnaire, physical examination, and had radiographs taken of both knees. Eight (21%) patients had surgeries for meniscal injuries after their posterior cruciate ligament injuries. The mean questionnaire score for function (50-point maximum) was 34.4 ± 6.5 (SD) for the pa tients who did have meniscal surgeries versus 40.0 ± 8.7 for the 30 patients who did not (P = 0.05). Among the 30 patients with isolated posterior cruciate liga ment-deficient knees with normal menisci, 24 (81%) had at least occasional pain and 17 (56%) had at least occasional swelling. As time from injury increased, increased articular degeneration on radiographs was seen (P = 0.037). Our study suggests that the prog nosis for the isolated posterior cruciate ligament-defi cient knee varies. Some patients experience significant symptoms and articular deterioration, while others are essentially asymptomatic and maintain their usual knee function.
The Popliteofibular Ligament
Authors: Maynard Michael J. , Xianghua Deng  , Wickiewicz Thomas L. , Warren Russell F.
Published: June 2007

We have recently become aware of a strong direct attachment of the popliteal tendon to the fibula. To investigate the importance of this attachment, we ex amined 20 cadaveric knees. The popliteofibular liga ment was identified in all 20 knees. The cross-sectional area of the popliteofibular ligament was 6.9 ± 2.1 mm 2, compared with 7.2 ± 2.7 mm2 for the lateral collateral ligament. Biomechanical testing of these structures, simulating a purely varus stress on the knee, revealed that the lateral collateral ligament always failed first, followed by the popliteofibular ligament, and then the muscle belly of the popliteus. The mean maximal force to failure of the popliteofibular ligament approached 425 N (range, 204 to 778), compared with 750 N (range, 317 to 1203) for the lateral collateral ligament. Our results indicate that the popliteofibular ligament contributes to posterolateral stability.
The Relationship Between Tunnel Placement and Clinical Results After Anterior Cruciate Ligament Reconstruction
Authors: Khalfayan Elias E. , Sharkey Peter F. , Alexander A. Herbert , Bruckner James D. , Bynum E. Bruce
Published: June 2007

To correlate clinical results after anterior cruciate liga ment reconstruction with tunnel placement measured radiographically, we prospectively studied 128 patients who had arthroscopically assisted bone-patellar ten don-bone reconstructions. Patients with bilateral ante rior cruciate ligament reconstructions, other significant knee ligament injuries, or those undergoing chondro plasty or meniscal repairs were excluded, leaving 42 patients. The relationship between radiographic tunnel position and clinical results was determined using the Lysholm score, KT-1000 arthrometer testing, the Teg ner activity level, and the pivot shift and Lachman tests. Clinical results correlated positively with posterior fem oral tunnel placement on lateral radiographs and neg atively with excessive anterior tibial tunnel placement. Specifically, when femoral tunnels were placed at least 60% posterior along Blumensaat's line and tibial tun nels were at least 20% posterior along the tibial pla teau, 69% of patients had good or excellent Lysholm scores and 79% had KT-1000 arthrometer maximum manual side-to-side differences of 3 mm or less. When the above criteria were not met, 50% of patients had good or excellent Lysholm scores and 22% had KT- 1000 arthrometer maximum manual side-to-side differ ences of 3 mm or less. This close correlation indicates that satisfactory radiographic tunnel position influences outcome after anterior cruciate ligament reconstruc tion.
Stability of the Braced Ankle
Authors: Thonnard J.L. , Bragard D. , Willems P.A. , Plaghki L.
Published: June 2007

We measured the bare ankle and the braced angle- torque relationships in 12 uninjured volunteers under static and dynamic conditions within the full range of inversion motion. These relationships were measured with a specially designed mechanical device that al lowed inversion movements with angular velocities up to 850 deg/sec. In testing the bare ankle under static conditions, the torque showed a 10-fold increase within the full range of motion (average, from 0.9 N-m at 7° to about 8 N-m at 48° of inversion). The slope of the angle-torque relationship increased under dynamic conditions giving higher torque values (up to 18 N-m on average). Both orthoses induced similar additional torques that increased linearly, up to about 6 N-m at 45°, with higher angles of inversion. These additional torques are small compared with the amount of stress applied to the foot during a typical ankle sprain situa tion, such as recovering from a jump. Therefore, we propose that orthotic devices increase the ankle torque, counteracting the inversion movement, and also prevent the start of the inversion movement by preloading and maintaining the ankle in a proper ana tomic position with optimal contact between the artic ular surfaces.
Electromyographic Latency Changes in the Ankle Musculature During Inversion Moments
Authors: Lynch Scott A. , Eklund Ulf , Gottlieb Dan , Renstrom Per A. F. H. , Beynnon Bruce
Published: June 2007

Ten uninjured subjects (ages 18 to 30 years) had electromyographic testing of the peroneus longus, per oneus brevis, and tibialis anterior muscles in response to inversion moments at two speeds (50 and 200 deg/ sec) and two joint angles (neutral and 20° of plantar flexion) using a hydraulically controlled tilt platform. Subjects underwent 10 trials of each type of inversion moment on Day 1 testing, which included both legs. On Day 2, subjects again underwent 10 trials of each type of inversion moment, but only on one leg. Reliability was assessed by comparing left and right leg data within muscle groups for Day 1 testing. Repeatability was assessed by comparing Day 1 with Day 2 data. The latency measurements (the time between the be ginning of the inversion moment and the onset of first motor response) for the peroneus brevis and tibialis anterior muscles were found to be reliable and repeat able with no significant differences between the same muscle groups. The peroneus longus muscle had a significant difference between legs but was found to be highly repeatable. Speed of inversion moment and plantar flexion angle both caused significant changes in latency response of the peroneus muscles, with increased speed producing a shorter latency response and increased angle causing a longer latency re sponse. Our results indicate a loss of protective re flexes with increasing plantar flexion.
Proprioception in Classical Ballet Dancers
Authors: Leanderson Johan , Eriksson Ejnar , Nilsson Charlotte , Wykman Anders
Published: June 2007

We studied prospectively the influence of ankle sprains on proprioception as measured by recording the pos tural sway of classical ballet dancers. Excellent bal ance and coordination are important for classical ballet dancers, and postural stability requires adequate pro prioception from the ankle joint. Fifty-three professional dancers from the Royal Swedish Ballet, Stockholm, and 23 nonathletes, the control group, participated in the investigation. Postural sway was recorded and an alyzed with a stabilimeter using a specially designed, portable, computer-assisted force plate. Six dancers sustained ankle sprains during followup. The record ings were obtained of these dancers before and after the injuries. The stabilometry results differed among the male and female dancers and the control group as follows: 1) the male dancers demonstrated a smaller total area of sway, and 2) both the male and female dancers had a smaller mean sway on the left foot than on the right (no mean difference in sway was found between the left and right foot in the control group). In comparison with the condition before injury and with the uninjured foot, the postural stability of the dancer was impaired for several weeks after the ankle sprain. Postural stability gradually improved during rehabilita tion and improvement still occured several weeks after professional dancing had resumed.
Biomechanics of Iliotibial Band Friction Syndrome in Runners
Authors: Orchard John W. , Fricker Peter A. , Abud Anna T. , Mason Bruce R.
Published: June 2007

We propose a biomechanical model to explain the pathogenesis of iliotibial band friction syndrome in dis tance runners. The model is based on a kinematic study of nine runners with iliotibial band friction syn drome, a cadaveric study of 11 normal knees, and a literature review. Friction (or impingement) occurs near footstrike, predominantly in the foot contact phase, between the posterior edge of the iliotibial band and the underlying lateral femoral epicondyle. The study subjects had an average knee flexion angle of 21.4° ± 4.3° at footstrike, with friction occurring at, or slightly below, the 30° of flexion traditionally described in the literature. In the cadavers we examined, there was substantial variation in the width of the iliotibial bands. This variation may affect individual predisposition to iliotibial band friction syndrome. Downhill running pre disposes the runner to iliotibial band friction syndrome because the knee flexion angle at footstrike is reduced. Sprinting and faster running on level ground are less likely to cause or aggravate iliotibial band friction syn drome because, at footstrike, the knee is flexed be yond the angles at which friction occurs.
Biologic Remodeling after Anterior Cruciate Ligament Reconstruction Using a Collagen Matrix Derived from Demineralized Bone
Authors: Jackson Douglas W. , Simon Timothy M. , Lowery Wylie , Gendler El
Published: June 2007

A matrix of demineralized cortical bone was used to reconstruct the anterior cruciate ligament in the goat model. This graft underwent considerable site-specific remodeling and transformation from a Haversian sys tem at time zero into a ligament-like structure at 1 year. This transformation included new bone formation filling the osseous tunnels and replacing the demineralized matrix, development of a ligament-like transition zone within the graft, and ligamentous collagen orientation with crimp in the intraarticular portion of the graft. One year after surgery, the mean anterior-posterior trans lation in the reconstructed stifle joints at 30 N of tibial loading was 2.1 ± 0.4 mm (±SEM). The mean ultimate force to failure for the reconstructed ligament at 1 year was 474 ± 146 N compared with the time-zero (initial) strength of the matrix of 73 ± 9 N. The cellular repopu lation of the graft had no associated inflammatory cells. The potential clinical significance of these findings in cludes 1) replacement of a collagen matrix with bone within the osseous tunnels, 2) establishment of a more physiologic fibrocartilage transition at the graft inser tion site, 3) the time-zero structural properties of a collagen matrix increasing to more desired values with biologic remodeling, and 4) a sterile biologic allograft with essentially no long-term inflammatory response.
Surgical Restoration to Treat Chronic Deficiency of the Posterolateral Complex and Cruciate Ligaments of the Knee Joint
Authors: Noyes Frank R. , Barber-Westin Sue D.
Published: June 2007

We report the results of treatment of combined defi ciency of the posterolateral complex and one or both cruciate ligaments. The posterolateral complex defi ciencies were corrected by a proximal advancement procedure of the lateral collateral ligament and pos terolateral complex tissues. The cruciate ligaments were reconstructed with either autogenous or allogenic tissue. Twenty-three consecutive patients were in cluded in the study, 21 returned for followup at a mean of 42 months (range, 23 to 94) postoperatively, and one reconstruction failed before the 2-year evaluation. The results were evaluated using the Cincinnati Knee Rating System. Using another classification system that assesses lateral joint opening, external tibial rota tion, and varus recurvatum tests, we found the pos terolateral advancement was fully functional in 14 knees (64%) at followup; in 6 knees (27%) there was partial function; and in 2 knees (9%) the advancement had failed. The proximal advancement represents a simplified method to restore tension in the posterolat eral complex. It allows early knee motion and is war ranted in knees in which structurally intact but lax ligamentous structures are present. The procedure is not performed when inadequate, thinned, or scarred posterolateral structures exist (these require graft re construction) or in varus-aligned knees. Associated cruciate ligament deficiencies should be surgically cor rected at the time of the posterolateral advancement procedure.