Showing papers in "American Journal of Sports Medicine in 1986"
TL;DR: There was no difference in the weightbearing characteristics of the meniscus when repaired by open versus arthroscopic technique when the knee is loaded at 0° flexion, and data suggest that theMeniscus does have a weightbearing role.
Abstract: The role of the meniscus in load transmission across the knee has long been a subject of debate. In this study, we examined the biomechanical consequences of the operative treatments for bucket-handle and peripheral meniscal tears. Contact areas and instantaneous intraarticular pressure distributions were measured in two groups of human cadaver knees. In Group I, consisting of four knees, we created a bucket-handle tear involving the inner one-third of the meniscus, followed by partial, and then total meniscectomy. Knees were tested in an Instron testing machine after each procedure, using a 400 pound load at 0 degrees or 30 degrees flexion. Contact areas and local stresses were measured using Prescale, a pressure-sensitive film. After partial meniscectomy, contact areas decreased approximately 10%, and peak local contact stresses (PLCS) increased approximately 65%. After total meniscectomy, contact areas decreased approximately 75%, and PLCS increased approximately 235%. In Group II, consisting of three additional knees, we created a 2 cm peripheral tear of the posterior meniscal horn, followed by open repair, arthroscopic repair, segmental, and then total meniscectomy. Repair of the tear was accomplished with either vertically placed sutures by an open technique or horizontally placed sutures by an arthroscopic technique. Knees were tested in the neutral position in the Instron machine and contact areas and local stresses measured using Prescale. PLCSs and contact areas were found to be the same using either repair technique. There was, however, a 110% increase in PLCS after segmental meniscectomy of that portion of the meniscus involved in the peripheral tear.(ABSTRACT TRUNCATED AT 250 WORDS)
771 citations
TL;DR: Strain in the ACL during simultaneous hamstring and quadriceps activity was significantly higher than that during passive normal motion from full extension to 30° of flexion, indicating hamstring exercises are not detrimental to ACL repairs or reconstruction and can be included early in the rehabilitation program after ACL surgery.
Abstract: The objectives of this study were to measure strain in the ACL during simulated: hamstring activity alone, quadriceps activity alone, and simultaneous quadriceps and hamstring activity. Seven knee specimens removed from cadavers were studied. Heavy sutures applied to load cells were attached to the hamstring and quadriceps tendons. Loads were then applied manually (hamstrings) and/or with an Instron testing machine (quadriceps) to simulate isometric contractions of the various muscle groups. Strain was measured using a Hall effect transducer. Acting alone, the isometric hamstring activity decreased ACL strain relative to the passive normal strain at all positions tested. Thus, hamstring exercises are not detrimental to ACL repairs or reconstruction and can be included early in the rehabilitation program after ACL surgery. Acting alone, at flexion angles of 0 degree to 45 degrees, the quadriceps significantly increased the strain within the ACL relative to the passive normal strain. Strain in the ACL during simultaneous hamstring and quadriceps activity was significantly higher than that during passive normal motion from full extension to 30 degrees of flexion. The hamstrings are not capable of masking the potentially harmful effects of simultaneous quadriceps contraction on freshly repaired or reconstructed ACLs unless the knee flexion angle exceeds 30 degrees.
572 citations
TL;DR: For both sexes the most common areas injured were the knee and ankle, with sprains/strains the most com mon injuries and injuries involving the patellofemoral artic ulation were significantly more frequent among females.
Abstract: Injuries treated at the University of Rochester Section of Sports Medicine over a 7 year period were surveyed. Patients were drawn from professional, intercollegiate (Division III), high school, intramural, and unorganized athletics at the University and the surrounding community. Data on injury diagnosis was available for 4,551 cases, with data on age, gender, and sport of injury available for 3,431 of the cases. The average patient age was 21.6 years, with a peak in the 16 to 19 age group. Patients with fractures had an average age below the overall mean, while those with internal derangement of the knee, patellofemoral pain syndrome, and inflammatory injuries were significantly older than average. Males accounted for 80.3% of all injuries. For both sexes the most common areas injured were the knee and ankle, with sprains/strains the most common injuries. Injuries involving the patellofemoral articulation were significantly more frequent among females. The most common sport of injury was football, with greater than 12 times the number of injuries seen in the next most common sport.
496 citations
TL;DR: It is concluded that the majority of athletes with isolated PCL injuries who maintain strength in muscu lature return to sports without functional disability.
Abstract: The long-term results of 25 patients treated nonoperatively with isolated posterior cruciate ligament (PCL) injuries were evaluated. Mean followup was 6.2 years (range, 2.2 to 16 years). All patients were evaluated both subjectively (questionnaire) and objectively (clinical examination, x-ray films, Cybex II dynamometer, and KT-1000 Knee Arthrometer). At followup, 80% of the patients were satisfied with their knees and 84% had returned to their previous sport (68% at the same level of performance, 16% at a decreased level of performance). Mean torque Cybex II quadriceps values for three velocities of testing (45, 90, and 180 deg/sec) in patients fully returned to sport and satisfied with their knees was greater than 100% of uninvolved quadricep; conversely, those not satisfied with their knees all had values less than 100% of uninvolved knee. The amount of knee instability as determined by the KT-1000 Arthrometer was not related to the patient's return to sport nor to knee satisfaction. We concluded that the majority of athletes with isolated PCL injuries who maintain strength in musculature return to sports without functional disability.
446 citations
TL;DR: Patients with predis posing factors such as patellofemoral malalignment, abnormal patellar configuration, and a history of prior symptoms of instability were more prone to recurrent dislocation and may benefit from operative intervention.
Abstract: Of 27 patients sustaining primary patellar dislocations, 20 were treated with immobilization and subsequent physiotherapy (including nine patients who underwent arthroscopy) and seven with immediate surgical stabilization and lateral release. The patients with predisposing factors such as patellofemoral malalignment, abnormal patellar configuration, and a history of prior symptoms of instability were more prone to recurrent dislocation and may benefit from operative intervention. Although the incidence of recurrence among those individuals can be decreased, at least 30% to 50% of all patients having sustained a primary patellar dislocation will continue to have symptoms of instability and/or anterior knee pain.
426 citations
TL;DR: A performance test simulating components of sports was devised to evaluate dysfunction after ACL injury and it is concluded that a performance test of this design is useful for monitoring rehabilitation and for evaluating the patient's condition.
Abstract: A performance test simulating components of sports was devised to evaluate dysfunction after ACL injury. The test included a one-leg hop, running in a figure of eight (straight running and turn running measured separately), running up and down a spiral staircase, and running up and down a slope. Twenty-six men with ACL injury, most of them soccer players, and 66 uninjured male soccer players were studied. Patients with ACL injury performed significantly less well than the uninjured players. Test items of special interest were turn running in the figure of eight, stair running, and slope running, all of which place high demand on the knee. It is concluded that a performance test of this design is useful for monitoring rehabilitation and for evaluating the patient's condition. Before sports can be resumed at the original level, normal strength and normal performance should be regained.
362 citations
TL;DR: The iliopatellar band provides stabilization of the patella against a medially directed force and is dynamically influenced by the vastus lateralis, and the relationship of the iliotibial tract to extraarticular reconstructions of the knee with anterolateral rotatory instability is discussed.
Abstract: Based on an extensive review of the literature and dissections of 17 fresh-frozen knee specimens, the authors divide the lateral fascia lata of the knee into two functional components: the iliopatellar band and the iliotibial tract. Aponeurotic, superficial, middle, deep, and capsulo-osseous layers contribute to these two functional components.The superficial layer of the iliotibial tract, combined with the deep, and capsulo-osseous layers, is hypoth esized to function as an anterolateral ligament of the knee. The iliopatellar band provides stabilization of the patella against a medially directed force and is dynam ically influenced by the vastus lateralis.The relationship of the iliotibial tract to extraarticular reconstructions of the knee with anterolateral rotatory instability is discussed.
355 citations
TL;DR: The potential seriousness of the ankle sprain in the young athlete is emphasized and a recommended method of management is presented, including as sessment of severity, treatment, and rehabilitation.
Abstract: To study the incidence of fibulocollateral ligament ankle sprains in the young male athlete, a survey of 84 varsity basketball players was done. Seventy percent of the players had a history of an ankle sprain. Eighty percent of those with a positive history had multiple sprains. Most of the injuries were mild, but in 32% of the injuries, the athlete missed more than 2 weeks of play. No medical attention was sought in 55% of the cases. About 50% of the athletes with a sprain had residual symptoms from their injuries; 15% of the injured athletes felt that their residual symptoms compromised their playing performance. This article emphasizes the potential seriousness of the ankle sprain in the young athlete and presents a recommended method of management, including assessment of severity, treatment, and rehabilitation.
293 citations
TL;DR: This report is an attempt to analyze what happens to an isolated ACL tear that is treated nonoperatively in patients treated initially by nonoperative means for this injury and followed an average of 4 years.
Abstract: This report is an attempt to analyze what happens to an isolated ACL tear that is treated nonoperatively. The results of 40 patients treated initially by nonoperative means for this injury and followed an average of 4 years are reported. A very small percentage of these patients had associated meniscal pathology. Secondary reconstructive surgery was necessary in 12 patients (30%). Primary meniscal tears were present in 4 of 25 knees (16%) and secondary meniscal tears occurred in an additional four of the patients. Giving way was a problem for 36 (86%) of the nonoperated patients, but pain and swelling were not significant problems for most. Full return to unlimited athletic activities was possible for only four (14%) of the patients. Objective signs of ACL insufficiency could be demonstrated on all patients upon clinical examination at followup. Overall grading of the knees revealed 87.5% fair or poor results.
289 citations
TL;DR: There was little or no activity in the gastrocnemius or in the intrinsic muscles of the foot about the time of toe-off, leading the authors to conclude that push-off per se does not appear to occur.
Abstract: An electromyographic study of the lower extremity muscles was undertaken in order to compare jogging, running, and sprinting. The study demonstrated that as the speed of gait increased, the support phase decreased, from 620 msec for walking to 260 msec for jogging to 220 msec for running to 140 msec for sprinting. The electromyographic data demonstrated that all muscle groups except the hip flexor and adductor longus were active during foot descent, floor contact, and midsupport. There was absence of muscle function during the late toe-off phase except that demonstrated by the adductor longus and the abdominal muscles during sprinting. The main muscle group that appears to increase the speed of gait is that of the hip flexors, which is closely linked to the knee extensors in order to propel the body forward in the line of progression. There was little or no activity in the gastrocnemius or in the intrinsic muscles of the foot about the time of toe-off, leading the authors to conclude that push-off per se does not appear to occur.
263 citations
TL;DR: Injured runners differed significantly from noninjured runners in that they were more likely to have run more miles per week and run more days per week, and run a faster pace, while compliance with medical advice correlated well with treatment.
Abstract: As the number of runners has increased dramatically, so has the incidence of running-related injuries. In order to determine what training factors are associated with running-related injuries, as well as what percentage of injured runners seeks professional medical attention, a random sample of entrants to a 10 kilometer race was asked to complete a questionnaire. There were 451 respondents, 355 men and 96 women, with a nonresponse rate of 12.7%. Nonrespondents did not differ from respondents with regard to age or sex. Forty-seven percent of respondents indicated that they had sustained a running-related injury in the last 2 years. Injured runners differed significantly from noninjured runners in that they were more likely to have run more miles per week, run more days per week, run a faster pace, run more races in the last year, stretched before running, and not participated regularly in other sports. Associated with injury, but not statistically significant, were those who had run marathons and had done muscle-strengthening exercises. No association was found with regard to the length of time running, running surfaces, part of the foot first contacting the ground, or running intervals, sprints, or hills. Seventy percent of those injured sought professional medical care, with 76% of these having a good or excellent recovery from their injuries. Compliance with medical advice correlated well with treatment success.
TL;DR: The data support an accurate preoperative diagnosis in ACL deficient knees when the Lachman and pivot shift tests are positive, and essentially rules out this type of injury when these tests are negative.
Abstract: Eighty-five patients with knee injuries were included in a 4 month retrospective study that compared the rela tive accuracy of the Lachman test, the anterior drawer sign, and the pivot shift test. All examinations were performed under anesthesia and followed by arthros copy, which confirmed 22 injuries. Of all ACL injuries occurring within 2 weeks of arthroscopy (N = 9), the pivot shift test was the most sensitive (88.8%), followed by the Lachman test with a 77.7% sensitivity. The anterior drawer sign was the least sensitive at 22.2%. All had specificities more than 95%. For all injuries of more than 2 weeks (N = 13), the Lachman and pivot shift tests were 84.6% sensitive, while the anterior drawer sign increased to a sensitivity of 53.8%. Again, all were specific to more than 95%. For all ACL injuries, irrespective of age, the Lachman test was 81.8% sen sitive and 96.8% specific; the anterior drawer sign was 40.9% sensitive and 95.2% specific; and the pivot shift was 81.8% sensitive and 98.4% specific. T...
TL;DR: Data suggest that PT autografts undergo a process of "ligamentization" when placed in the ACL environment, and that cells responsible for this meta morphosis are of extragraft origin.
Abstract: A rabbit model for ACL reconstruction using autogenous patellar tendon (PT) was used to study graft viability, its response to new physical forces, and the intrasynovial milieu. The autograft was assessed grossly, histologically, and biochemically with respect to time. Histologic observations demonstrated that autografts were centrally acellular with a peripheral rim of cells at 2 weeks, and had a central focal proliferation of cells at 3 weeks and cellular homogeneity by 4 weeks postoperation. Necrosis followed by cellular proliferation suggested that a population of cells other than the native PT fibroblasts may be inhabiting the graft. Graft sequestration experiments demonstrated that autografts are repopulated by cells of extrinsic origin after transplantation. Autografts showed a gradual assumption of the microscopic properties of normal ACL; by 30 weeks posttransplant the tissue characteristics were ligamentous in appearance. Histologic changes paralleled the biochemical metamorphosis: Type III collagen was not observed in PT; however, a gradual increase in its concentration was seen in the grafts; by 30 weeks its concentration (10%) was the same as in normal ACL. Similarly, glycosaminoglycan content increased from its normally low level in PT to that found in native ACL. Collagen-reducible cross-link analysis revealed that grafted tissue changed from the normal PT pattern of low dihydroxylysinonorleucine and high histidinohydroxymerodesmosine to the opposite pattern seen in normal ACL by 30 weeks. These data suggest that PT autografts undergo a process of "ligamentization" when placed in the ACL environment, and that cells responsible for this metamorphosis are of extragraft origin.
TL;DR: It is believed that a cryopre served ACL allograft can provide the ideal material for ACL reconstruction and a surgical technique is outlined for harvesting and implanting this graft clinically.
Abstract: In recent years much effort has been devoted to finding a satisfactory replacement for the injured ACL. None of the reconstruction techniques used in the past can be considered ideal because of their inability to duplicate the complex geometry, structure, and function of the ligament. Current advances in allograft transplantation and cryopreservation have led us to design and implement an experimental model for testing the feasibility of cryopreserved ACL allotransplantation. Groups of dogs were used to evaluate the effect of cryopreservation on ligament strength and to compare the relative performance of both autograft and allograft ACL transplants up to 18 months after implantation. The ligaments were examined mechanically, histologically, and microangiographically. The cryopreservation process and duration of storage had no effect on the biomechanical or structural properties of the ligament. The mechanical integrity of the allografts was similar to that of the autografts, with both achieving nearly 90% of control ligament strength by 36 weeks. Revascularization approached normal by 24 weeks in both autograft and allograft. No evidence of structural degradation or immunological reaction was seen. Based on these results, we believe that a cryopreserved ACL allograft can provide the ideal material for ACL reconstruction. We have outlined a surgical technique for harvesting and implanting this graft clinically.
TL;DR: If cyclic loading or tension is anticipated at the fixation site, the fixation technique of choice would be the screw with spiked plastic washer or soft tissue fixation plate.
Abstract: This experiment was designed to compare the immediate fixation strengths of various methods of soft tissue fixation techniques. The fixation techniques tested were the barbed staple, stone staple, suture techniques, screw with spiked plastic washer, and the screw with spiked soft tissue plate. Cadaveric soft tissue specimens were classified into three distinct morphologic types: capsular, tendinous, and extensor mechanism tissue. Each specimen was fixed to bone by one of the fixation techniques. The specimens were loaded in a cyclical fashion until fixation failure occurred. One hundred thirty-seven trials were performed. The screws with the spiked plastic washer and soft tissue plate proved superior overall for all three tissue types. The stone staple was the poorest technique tested. Therefore, if cyclic loading or tension is anticipated at the fixation site, the fixation technique of choice would be the screw with spiked plastic washer or soft tissue fixation plate.
TL;DR: It is suggested that even in chronic lesions, arthroscopic surgery can yield a high percentage of excellent or good results with minimal morbidity, brief hospitalization, and a rapid recovery time for the patient by avoiding long skin incisions and deep soft tissue dissections, grooving of the distal tibia, or osteotomy of the medial malleolus.
Abstract: A retrospective study of the arthroscopic treatment of transchondral fractures of the talar dome in 18 patients was conducted. Followup ranged from 3 months to 3 years; 10 patients had an average followup of 2 years (Group A) and 8 of 6.5 months (Group B). The 10 male and 8 female patients ranged in age from 14 to 40 years. Thirteen lesions were posteromedial while five were anterolateral. Fourteen of the 18 patients reported an inversion type injury to the ankle from playing various sports on weekends. One patient had a bimalleolar fracture of the ankle sustained in a car accident 18 months prior to referral, while the last patient in the series had a bilateral fracture of the os calcis from a work-related falling incident. All patients underwent conservative care for at least 4 months prior to referral. Arthroscopic treatment consisted of partial synovectomy, debridement of osteochondral lesions with removal of loose fragments, curettage, abrasion, and, in one case, drilling. For analysis of postoperative management, patients were divided into two groups, 10 with the 2 year followup comprising Group A and the 8 with the 6.5 month followup in Group B. Group A was nonweightbearing for 6 weeks while Group B was ambulatory 2 weeks postoperatively. Group A was fully ambulatory when the 6 week nonweightbearing period expired. All patients had a full range of motion at the time of suture removal (1 week to 10 days). Both groups were evaluated objectively and subjectively. Excellent or good results were obtained in 88% of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: Achieving quadriceps and hamstring torque of 86% and 96%, respectively, was not sufficient to eliminate the subjective need for ACL reconstruction and may be the first means to assess the functional pivot shift phenomenon ever documented.
Abstract: Eighteen males and two females (mean age, 26.5 years) underwent biomechanical assessment and Cybex eval uation prior to ACL reconstruction. Clinically, all patients had at least a 1+ grade with the Lachman, anterior drawer, and pivot shift tests, the majority being graded as 2+. Footswitch, high speed photography, force plate, and indwelling wire electrode data were collected while each subject performed free and fast walking, running, cutting, and stair climbing activities.During walking, single limb support times did not differ between the subject's involved and uninvolved limbs. Knee joint angles were similar between limbs during walking, running, and stair climbing maneuvers. Dynamic EMG tracings during walking demonstrated similar quadriceps and calf activity between limbs, while greater variation in hamstring firing was evident among subjects. During running, the involved limb had a longer duration of medial hamstring activity compared to the lateral hamstring.No significant differences were seen in...
TL;DR: It is concluded that muscle strains continue to weaken in the early postinjury period and non steroidal antiinflammatory medication, such as piroxi cam, might delay muscle regeneration.
Abstract: The healing process of muscle strains and the effect of nonsteroidal antiinflammatory medication were studied using an experimental animal model. A standardized strain of the tibialis anterior muscle in adult male rats was produced by a controlled stretch of the muscle. Groups I and II underwent a unilateral strain of the tibialis anterior muscle and were immobilized in the postinjury period. The rats in Group II were fed piroxi cam in the postinjury period. Group III underwent a sham procedure and were also immobilized. At 0, 2, 4, and 11 days postinjury both injured and contralateral control muscles were evaluated by determining tensile strength characteristics and histologic appearance.Group I showed a significant drop in maximum failure load to 25.7% of the control leg at Day 2 with a gradual return to the level of Group III at Days 4 and 11 (40.9% and 50.1 %). Group II showed a similar drop but was still stronger than Group I at 2 days with 40.8% of the control leg and continued to drop until 4 days ...
TL;DR: There is a strong implication that simple muscle training does not increase the speed of muscular reaction but dynamic joint control training has the potential to shorten the time lag of muscular reac tion.
Abstract: The purpose of this study was to introduce dynamic joint control training and to assess its effects in improv ing neuromuscular coordination of injured knees using the Kin-Com Isokinetic Dynamometer. Although four patients had a sensation of "giving way" on one knee, all eight knees were trained for 3 months using unstable boards with added sudden force given by a therapist. The training group (four patients) was examined during four sessions and the control group (five subjects) was examined during three sessions within a 3 month pe riod. All subjects were instructed to react to the sudden forward movement of the input arm of the Kin-Com Isokinetic Dynamometer with contraction of the ham string. Results of the first and final trials of peak torque time (PTT) and rising torque value (RTV) of the ham string between the training and control groups showed significant improvement. There was no correlation be tween isometric muscle strength (IMS) and PTT in the total 76 sessions. There is a strong implication ...
TL;DR: MRI in conjunction with clinical evaluation can contrib to treatment decision-making processes and assist in preoperative planning and an algorithm demonstrating the potential clinical use of MRI is presented.
Abstract: Traumatic injury to the knee remains a diagnostic and therapeutic challenge. Magnetic resonance imaging (MRI) has been applied to musculoskeletal pathoanatomy and has been shown to be an effective tool for definition and characterization of knee pathology. A systematic approach is taken to establish anatomical and pathoanatomical correlations, as well as the role of MRI in the management of knee injuries. Imaging was performed at the UCLA Medical Center using a permanent magnet system and a combination of solenoidal surface coils and thin-section, high-resolution scanning techniques. Images depict structural anatomical and spatial details of the knee that correlate well with corresponding cadaveric cryosections. To determine pathoanatomical correlations and the efficacy of MRI, 105 patients with preoperative diagnoses of meniscal tears, anterior and posterior cruciate ligament tears, tibial plateau fracture, and patella and quadriceps injuries were imaged. Results indicated that for the medial meniscus MRI demonstrated a 95.7% sensitivity, 81.8% specificity, 90% accuracy, 88.2% positive predictive value (PPV), and 93.1% negative predictive value (NPV). Imaging of the lateral meniscus demonstrated a 75% sensitivity, 95% specificity, 91% accuracy, 80% PPV, and 94% NPV. MRI of the ACL revealed 100% sensitivity, specificity, accuracy, positive and negative predictive values. MRI is a noninvasive tool which uses no ionizing radiation and can accurately define and characterize anatomy and pathoanatomy. This study indicates that MRI in conjunction with clinical evaluation can contribute to treatment decision-making processes and assist in preoperative planning. An algorithm demonstrating the potential clinical use of MRI is presented.
TL;DR: A prospective study was done on Indiana University freshman football players to determine if the incidence of lumbar spondylolysis and spONDylolisthesis followed the pattern of previous studies, and some other problems, such as spina bifida occulta, were found.
Abstract: A prospective study was done on Indiana University freshman football players to determine if the incidence of lumbar spondylolysis and spondylolisthesis followed the pattern of previous studies. Using x-ray film evaluation, 145 freshman players were followed through their careers from 1978 to 1983. As in previous studies, a higher percentage (15.2%) of the defect was found than exists in the general population. However, only 2.4% of these players developed the problem in college, a much lower figure than previously found. Affected team members played a variety of positions. In addition to spondylolysis, some other problems, such as spina bifida occulta, were found. Theories on the cause of spondylolysis and spondylolisthesis are reviewed, and preventive suggestions such as more careful training and weight lifting are presented.
TL;DR: For those patients with a symptomatic snapping hip and trochanteric bursitis unresponsive to conservative therapy, the procedure described is an effective method of treatment.
Abstract: This report concerns seven patients that had a painful hip due to snapping of the iliotibial band over the greater trochanter and resultant trochanteric bursitis, and whose symptoms were refractory to nonoperative treatment. An operative procedure that has not been previously described was performed. It involved the excision of an ellipsoid-shaped portion of the iliotibial band overlying the greater trochanter and removal of the trochanteric bursa. Five of the seven patients were evaluated at the time this report was prepared; the average length of followup was 55 months. Four were significantly improved or relieved of their symptoms, and the fifth was an operative failure with complete recurrence. This final patient underwent a second, more extensive partial excision of the iliotibial band, and was asymptomatic 1 year later. A review of the clinic records of the remaining two patients that could not be contacted revealed that they both had been doing well at their 6 month evaluation. For those patients with a symptomatic snapping hip and trochanteric bursitis unresponsive to conservative therapy, the procedure described is an effective method of treatment.
TL;DR: Results showed that implantation by the surgical technique was effective and no loose bodies or partial detachments were found in the reimplantation or tissue culture-stored allogenic menisci.
Abstract: A surgical procedure was developed such that a menis cus could be reimplanted in the medial compartment of canine knees. The medial meniscus was removed and reimplanted in one group of seven animals, removed and reimplanted with a glutaraldehyde-preserved bio prosthesis in a second group of five animals, and re moved and replaced by an allograft meniscus preserved 2 to 3 weeks in tissue culture in a final group of ten animals.All animals were autopsied at 2 months and the knees were examined by gross dissection and histologic study of the joint capsule meniscal interface.Results showed that implantation by the surgical technique was effective and no loose bodies or partial detachments were found in the reimplantation or tissue culture-stored allogenic menisci. Allogenic menisci pre served in glutaraldehyde and termed a bioprosthesis attached to the joint capsule less satisfactorily. There was minimal inflammation of the synovium in any group at 2 months; however, the glutaraldehyde group showed repeated e...
TL;DR: The findings suggest that the change in strength of an intraarticular ACL replacement relates more to a basic rearrangement of its collagen-ground substance relationships, and that vascularity may re flect the inflammatory response bringing about these changes.
Abstract: The methods and materials for ACL reconstruction are important issues for the practicing orthopaedic sur geon. In this study a model was developed to study the biological and biomechanical characteristics of a patel lar tendon autograft used for ACL reconstruction. Spe cifically it was hypothesized that since vascularity of these grafts reflects their "healthiness," strength and vascularity should be inversely related in the early pe riod after implantation. Using an over the top technique, a patellar tendon graft was placed in three groups of dogs and studied at 37, 57, and 120 days. Vascularity of the grafts was measured using technetium-tagged red blood cells, and percent water by weight was determined by dessication. Tensile testing to failure was performed using an MTS machine. The grafts became more vascular, more hydrated, less stiff, and less strong (by 4 weeks) than controls. By 16 weeks the vascular response was subsiding but the grafts remained only 40% as strong as controls. Percent water incr...
TL;DR: A biome chanical analysis of braced and unbraced tennis players (serve and backhand strokes) was undertaken to better understand the clinical success of counterforce bracing.
Abstract: Biomechanical data on most bracing and protective equipment systems is lacking. To better understand the clinical success of counterforce bracing, a biomechanical analysis of braced and unbraced tennis players (serve and backhand strokes) was undertaken. Three-dimensional cinematography and electromyographic techniques were used. Three commonly used counterforce braces (lateral elbow, medial elbow, and radial-ulnar wrist) were compared with the unbraced condition. The overall results basically reveal positive biomechanical alterations in forearm muscle activity and angular joint acceleration dependent upon the brace and joint area analyzed.
TL;DR: Cadaveric dissections have demonstrated the precar ious nature of the axillary nerve with relationship to three common sports medicine shoulder procedures: the anteroinferior acromioplasty and rotator cuff repair incision, the inferior capsular shift procedure, and the posterior portal for shoulder arthroscopy.
Abstract: Cadaveric dissections have demonstrated the precar ious nature of the axillary nerve with relationship to three common sports medicine shoulder procedures: the anteroinferior acromioplasty and rotator cuff repair incision, the inferior capsular shift procedure, and the posterior portal for shoulder arthroscopy.
TL;DR: Basketball players and distance runners experienced a transient increase in anterior and posterior laxity during exercise, and it appears that repetitive physiologic stresses at a high strain rate produce significant ligamentous laxity, while a relatively few large stresses at an low strain rate do not.
Abstract: A commercial knee laxity testing device was used to quantitate anterior and posterior laxity before and after exercise. Measurements were made at 20 degrees of knee flexion and with a displacement force of 133 N (30 pounds). In sedentary controls no significant change in laxity was noted over 2 hours. Squat power lifters sustained no significant change in laxity after a series of squats (0.4 to 0.7 cm) using 1.6 times body weight. However, 18% to 20% increases in mean anterior and posterior laxity were noted in college basketball players after 90 minutes of practice and in recreational runners after a 10 km race. The role of muscle relaxation in such tests was also evaluated by measuring laxity in normal knees before and during general anesthesia. Negligible laxity change was noted. Thus, functionally "complete" muscle relaxation can be obtained during testing in the cooperative individual. In conclusion, basketball players and distance runners experienced a transient increase in anterior and posterior laxity during exercise. Power lifters doing squats did not demonstrate a significant change in laxity. It appears that repetitive physiologic stresses at a high strain rate produce significant ligamentous laxity, while a relatively few large stresses at a low strain rate do not.
TL;DR: The incidence of injuries among youth soccer players (under age 16) participating in indoor soccer was 4.5 times that of youth players in outdoor soccer when calculated per 100 hours of team play, and 6.1 times greater when calculated every hour of player game participation.
Abstract: The incidence of injuries among youth soccer players (under age 16) participating in indoor soccer was 4.5 times that of youth players in outdoor soccer when calculated per 100 hours of team play, and 6.1 times greater when calculated per 100 hours of player game participation. Injuries were few among players under age 10 in either game, and the number of injuries increased with age in the older players. Medical assistance was required for 6.5% of the injuries among outdoor players and for 24.3% among indoor players. Overall, 66.6% of the injuries were the result of physical contact between players. No relationship was observed between the risk of injury and playing position, conduct of warm-up exercises, or the team having a licensed coach.
TL;DR: The results indicated a significant lengthening in knee joint laxity between preexercise and postexercise in the left knee as measured at 15 and 20 pounds of passive displacement force, which document an in vivo increase in the anterior laxity of the knee joint due to exercise.
Abstract: Knee injuries are the topic of increasingly sophisticated research because of the importance in professional athletics as well as increasing participation in recreational sports. The role of conditioning and fatigue in these injuries remains controversial. Ligaments have high collagen content, and a viscoelastic response to stress would be expected. Because of the postulated relationship between laxity and knee ligament injuries, an experiment was designed using highly motivated athletes to test the hypothesis that exercise to the point of muscular fatigue may cause laxity of the knee and thereby place athletes at risk for ligamentous injury to the knee when fatigued. An exercise protocol was designed to produce muscle fatigue in the hamstring and quadriceps muscle groups. Knee ligament laxity was tested prior to and subsequent to the exercise protocol. To document muscle fatigue, isokinetic testing of right knee flexion and extension power was used several times during the exercise protocol. A knee arthrometer (KT-1000) was used to quantitatively document ligamentous laxity before and after exercise. The results indicated a significant lengthening in knee joint laxity between preexercise and postexercise in the left knee as measured at 15 and 20 pounds of passive displacement force (P less than 0.05). Maximum manual displacement also demonstrated a significant increase in joint laxity (P = 0.02). The right knee, which had undergone isokinetic testing, demonstrated a similar tendency but without a statistically significant difference before and after exercise. There was no significant preexercise side to side difference, but postexercise measurements demonstrated a left-right difference at 15 pounds, 20 pounds, and maximum manual displacement of statistical significance (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: A consecutive series of patients who have undergone arthroscopy and lateral retinacular release for patello femoral subluxation was evaluated so that the results could be compared to an earlier series of open patel lofemoral reconstructions, and it is believed that a lateral ret inacular release involves less surgery than a formal patell ofemoral reconstruction.
Abstract: A consecutive series of patients who have undergone arthroscopy and lateral retinacular release for patellofemoral subluxation was evaluated so that the results could be compared to an earlier series of open patellofemoral reconstructions. Of 96 patients, 4 had bilateral releases; therefore, 100 knees were evaluated. The average age was 28 years. Specific symptoms and signs were reviewed. All patients were initially treated conservatively with specific exercises. Failure of the exercise program to improve symptoms significantly, the patient's inability to perform normal daily activities, or expected associated pathology were indications for surgery. The surgical technique consisted of arthroscopy with treatment of associated pathology and lateral retinacular release using the Smillie meniscotome through the inferior lateral portal. The patella could be tilted approximately 90 degrees medially when the release was accomplished. Pain, function, and patellar instability were evaluated preoperatively and postoperatively by signs of tenderness on the retinaculum or bone, patellar mobility, effusion, muscle atrophy, and tone. Range of motion was also evaluated. Average followup was 36 months. When evaluated subjectively by the patients, pain improved from a mean preoperative grade of 3.4 to 1.7 postoperatively, function improved from 3.4 to 1.7, and instability from 3.4 to 1.6. Objective evaluation found that tenderness on the patella improved from a mean preoperative grade of 3.3 to 1.7 postoperatively. Tenderness on the retinaculum improved from 3.2 to 1.7. Patellar mobility improved from 3.3 to 1.7. Effusion dropped from 3.2 preoperatively to 1.5 postoperatively; quadriceps atrophy from a mean preoperative grade of 3.2 to 1.5, and quadriceps tone from 3.2 to 1.6.(ABSTRACT TRUNCATED AT 250 WORDS)