The American Journal of Sports Medicine

Human immunodeficiency virus (HIV) infection via vas cular organ and tissue transplantation is well docu mented. The majority of these transmissions occurred before the development of HIV antibody testing, which is now a routine screening tool used before organ and tissue procurement and transplantation. There exists what is commonly referred to as a "window" of sero negativity after HIV infection. Potential donors may be infectious with the HIV virus but not yet detected with available HIV antibody tests. Bone and soft tissue retrieval may be done in either a sterile or clean, non- sterile manner. Deep freezing and freeze-drying (lyoph ilization) are two commonly used modes of preserving bone and soft tissue allografts.

In 1985, a screened donor who was in the window of seronegativity underwent vascular organ and mus culoskeletal tissue harvest. The bone and soft tissue procured underwent a variety of processing and pres ervation techniques. There have been no known cases of HIV transmission from the processed freeze-dried tissues.

Evidence now exists that early HIV infection, before HIV antibody production, may be the most infectious period. The HIV antigen testing may allow earlier detec tion of an infectious donor, thus closing the window of seronegativity. It is unknown whether this nontransmis sion of HIV to the recipients of the processed and freeze-dried tissue was due to the processing or the nature of the tissue itself.

Similar-sized patellar tendon autografts and fresh-fro zen allografts were used to reconstruct the anterior cruciate ligament of one knee in 40 female goats. Evaluations of the reconstructions and contralateral controls at the 6-week and 6-month postoperative pe riods included anterior-posterior translation, mechanical properties determined during tensile failure tests, meas urement of cross-sectional area, histology, collagen fibril size and area distribution, and associated articular cartilage degenerative changes.

Six months after anterior cruciate ligament recon struction, the autografts demonstrated a smaller in crease in anterior-posterior displacement, values of maximum force to failure two times greater, a significant increase in cross-sectional area, a more rapid loss of large-diameter collagen fibrils, and an increased density and number of small-diameter collagen fibrils compared to the allografts.

Clinical significance . More surgeons are allowing their patients to return to running and sports 6 months after anterior cruciate ligament reconstruction. While the structural and material properties of autografts and allografts at time zero are similar, in the goat model during the first 6 months they differ. The allografts demonstrate a greater decrease in their implantation structural properties, a slower rate of biologic incorpo ration, and the prolonged presence of an inflammatory response. At 6 months the autograft demonstrates a more robust biologic response, improved stability, and increased strength to failure values.

Twenty-nine cases of operative arthroscopy of the an kle were done between 1985 and 1989 for synovial impingement of the ankle. The average age of the patients was 37 years. All patients (17 men, 12 women) reported an earlier history of injury, with 24 of the patients (83%) noting chronic ankle pain after an inver sion injury and 5 of the patients (17%) reporting a previous ankle fracture. Physical examination elicited anterolateral tenderness at the ankle in all cases with associated anteromedial pain in 4 patients. A demon strable "click" was evident in 6 of the patients (21 %) on forced dorsiflexion of the ankle.

All patients failed conservative treatment including physical therapy and nonsteroidal antiinflammatory drugs. Surgery was performed at an average of 36 months postinjury. Ankle arthroscopy revealed exten sive hypertrophic synovial thickening and scar tissue anterolaterally, indicating synovial impingement in all patients. Associated chondromalacia of the distal tibia was seen in 21 % of the patients. Operative arthroscopy included partial synovectomy and debridement of the hypertrophic tissue and partial shaving chondroplasty of the tibia when indicated. Postoperatively, patients were weightbearing as tolerated. Results were as sessed subjectively and objectively.

At 25-month followup 26 patients had excellent or good results and 3 had fair results; there were no poor results. There were no major complications, including infection or neurovascular compromise. The 3 patients with associated ankle instability comprised the "fair" result group and eventually required lateral ankle recon struction. Thus, chronic ankle pain due to synovial impingement can be safely, predictably, and effectively treated by operative ankle arthroscopy.

The structural and functional strength of a muscle immediately after an experimentally created strain injury was examined to provide clinically relevant information for the early treatment of muscle strain injuries. The extensor digitorum longus muscles of 12 adult male rabbits were studied. Contractile force and shortening, and peak load were determined for control muscles. A nondisruptive strain injury was created by stretching the experimental muscles just short of complete rup ture. Contractile force generation and shortening, and peak load were determined after the experimental strain injury. Peak load was 63% and elongation to rupture was 79% for the experimental muscles relative to the controls. Statistically significant lower values for con tractile force generation and shortening were also seen in the experimental muscles. Histologic and gross ex aminations revealed that incomplete disruptions oc curred near the distal muscle-tendon junction. These experimental data suggest clinical implications, such as 1) a muscle-tendon unit is significantly more susceptible to injury following a strain injury than normal muscle, 2) early return to the uncontrolled environment of athletic competition may place the injured muscle at risk for further injury, and 3) therapeutic regimens designed to achieve an early return to competition may further increase the risk for additional injury by eliminating protective pain mechanisms. Although the decrements in peak load and elongation to failure are less than normal muscle, the values seem high enough to allow mobilization of the injured extremity and functional re habilitation.

To investigate if participation in sports increases the risk of developing osteoarthrosis of the hip, we did a case-control study on the sports activities of 233 men (up to age 49) who were recent recipients of a prosthe sis because of severe idiopathic osteoarthrosis of the hip and 302 men randomly selected from the general population. Assessments of sports, job history, and health status were made by an interview.

Men with high exposure to sports of all kinds com bined (in hours) had a relative risk to develop osteoar throsis of the hip of 4.5 compared to those with low exposure. Track and field sports and racket sports seemed to be the most hazardous to the hip joint. Men who had been exposed to high physical loads both from their occupation and sports had a relative risk of 8.5 to develop osteoarthrosis of the hip compared to those with low physical load in both activities. Potential confounding factors, such as age, body mass index, and smoking, were considered.

Long-term exposure to sports among men seems to be a risk factor for developing severe osteoarthrosis of the hip; this is increased when combined with heavy load from occupation.

Lower extremity equipment-related injuries are the most significant injury group in alpine skiing. The lower extremity equipment-related injuries occurring at four Norwegian ski resorts were studied during the winter of 1985 to 1986. A total of 132 skiers with injuries were included (40% of all injured skiers) and compared with a randomly selected control population of 316 uninjured skiers. The most common lower extremity equipment- related injuries were knee sprains (56%) and lower leg fractures (14%), usually caused by no or late binding release.

Significantly more lower extremity equipment-related injuries (33%) than other skiing injuries (19%) needed hospital admittance. Children below 10 years had a risk of lower leg fractures nine times that of skiers beyond 20 years. Beginners were six times more at risk for a lower extremity equipment-related injury than skiers of higher skiing abilities. The following factors were also associated with a significantly increased risk for a lower extremity equipment-related injury: less than three skiing seasons, no skiing instruction, and no self-testing of the bindings.

One hundred eighty-seven patients who had undergone intraarticular anterior cruciate ligament reconstruction using either a fresh-frozen allogeneic tendon or central third autogenous patellar tendon 3 to 89 months pre viously were arthroscopically evaluated. The focus was on secondary changes of the patellofemoral joint at the time of second-look arthroscopy. Overall, 93 knees deteriorated, 74 knees remained unchanged, and 14 improved. The deteriorative changes were predomi nantly located around the central ridge of the patellae, although all but two knees remained free from anterior knee pain. Statistical multivariate analysis showed sur gical approach by conventional medial parapatellar in cision and use of the central one-third of the autoge nous patellar tendon graft as possible risk factors for the deterioration, although chi-square analysis failed to demonstrate statistical significance for the latter.

Patients have complained of pain after the use of the central one-third patellar tendon for reconstruction of the anterior cruciate ligament-deficient knee. This study investigated the effect on patellofemoral contact areas and pressures of harvesting the central 10 mm of the patellar tendon in five cadaveric knees. Isometric quad riceps forces were applied to produce approximately 30% of reported maximum voluntary extension mo ments at the knee. Using Fuji pressure-sensitive film, measurements were recorded for three states: the normal knee, after the graft removal, and after the tendon was closed. Contact areas and pressures were measured at 20°, 30°, 60°, and 80° of knee flexion in each specimen. Tests of the reproducibility of our meth ods were performed.

Average patellofemoral contact areas for three states ranged from 1.6 cm² at 20° of knee flexion to 3.0 cm² at 60°. The average patellofemoral contact pressures ranged from 1.9 MPa at 20° of knee flexion to 3.0 MPa at 30°. At each flexion angle there were no significant differences in average patellar contact area or pressure for the three states (P < 0.05). These results suggest that neither harvesting the central 10 mm of the patellar tendon, nor closing the gap, significantly alters patello femoral contact area or pressure.

Magnetic resonance imaging of the knees of 98 con secutive patients with clinically diagnosed anterior cru ciate ligament injuries revealed 47 patients (48%) with focal signal abnormalities consistent with the diagnosis of a "bone bruise." Seventy-one percent of the magnetic resonance images taken within 6 weeks of injury dem onstrated a bone bruise, whereas no scans done longer than 6 weeks after injury showed a bruise (P < 0.0001). Also significant was the tendency for lesions to be located in the lateral compartment (P < 0.0001). In the sagittal plane, lesions were most likely to be in the middle third of the lateral femoral condyle and the posterior third of the lateral tibial plateau (P < 0.0001). In 31 patients evaluated arthroscopically, there was no correlation between the presence or location of a bone bruise and articular alterations or meniscal tears ob served at surgery.

The mechanical support provided by a semirigid ankle orthosis was tested in 14 ankles with symptoms of chronic lateral instability by use of stereophotogram metric analysis. Talar and calcaneal rotations were measured with and without the Strong ankle orthosis during manual adduction test and adduction test with a predetermined torque (5 N-m). Significant reduction of talar and calcaneal plantar flexion, internal rotation, and varus angulation was noted when the orthosis was applied. The results of this study suggest that the semirigid orthosis may provide enough external support to prevent ankle sprains and to protect ligament recon structions.

A cadaveric model that incorporated quadriceps and hamstrings muscle loads was developed to simulate the squat exercise. The addition of hamstrings load affected knee kinematics in two ways. First, anterior tibial translation during flexion ("femoral roll-back") was significantly reduced (P = 0.003) and second, internal tibial rotation during flexion was reduced (P = 0.008). However, quadriceps force was unaffected by the ad dition of hamstrings load. Thus, it seems likely that hamstrings muscle activity that has been observed in vivo during a squat probably functions synergistically with the anterior cruciate ligament to provide anterior knee stability.

After the ACL was sectioned, anterior tibial transla tion was significantly increased during the squat (P = 0.04). The anterior cruciate ligament was then recon structed using a graft instrumented with a load cell. During passive motion, maximal graft tension was at full extension. During simulated squat exercise, the addition of hamstrings caused a significant decrease in graft load ( P = 0.006). During the squat, maximal graft tension was at full extension, and was equal to the graft tension at full passive extension. Thus, the squat exercise may be useful in the early stages of anterior cruciate ligament rehabilitation.

Shoulder rotator cuff impingement syndrome is a com mon and disabling problem for the wheelchair athlete. In this study we investigated the role of shoulder strength imbalance as a factor for the development of this syndrome. Nineteen paraplegic male athletes underwent clinical and isokinetic examination of both shoulders with peak torque values measured in abduc tion, adduction, and internal and external rotation. Twenty athletic, able-bodied men without shoulder problems were tested as controls. Ten (26%) of the paraplegic athletes had rotator cuff impingement syn drome. The results of the isokinetic testing demon strated that 1) the paraplegics' shoulders were stronger than the controls in all directions (P < 0.05); 2) the strength ratio of abduction:adduction was higher for paraplegic athletes (P < 0.05); 3) paraplegics' shoulders with rotator cuff impingement syndrome were weaker in adduction and external and internal rotation than the paraplegic athletes without impingement syndrome (P < 0.05); and 4) paraplegics' shoulders with rotator cuff impingement syndrome had higher abduc tion:adduction and abduction:internal rotation strength ratios than the shoulders of paraplegics without im pingement syndrome (P < 0.05). We concluded that shoulder muscle imbalance, with comparative weak ness of the humeral head depressors (rotators and adductors), may be a factor in the development and perpetuation of rotator cuff impingement syndrome in wheelchair athletes.

The effect of early (mean, 5 months) versus late (mean, 9 months) return to vigorous cutting activity on the long-term outcome of anterior cruciate ligament recon struction was evaluated retrospectively. Sixty-four re constructions, using a distally attached medial one-third patellar tendon, were reviewed on an average of 46 months postoperatively. After surgery, the timing of return to vigorous activity was based on biologic fixa tion of the graft, a negative Lachman test, absence of effusion, and the patient's desire to return to previous activity.

The 64 patients were retrospectively separated into two groups. The early group consisted of 31 patients who returned to activity 2 to 6 months after reconstruc tion, and the late group consisted of 33 patients who returned to activity 7 to 14 months after reconstruction.

By clinical examination, KT-1000 arthrometer meas urements, subjective evaluation, and Cybex testing, there were no differences between the early and late return groups except for reestablishment of final range of motion.

At an average followup of 46 months, this study indicates that an early return to vigorous physical cut ting activities after ACL reconstruction does not predis pose patients to reinjury or a less satisfactory long- term result.

Fifty anterior cruciate ligament-deficient knees treated consecutively with arthroscopically assisted recon struction using a pes anserine tendon autograft were retrospectively studied. The mean followup was 36.7 months (range, 26 to 58). All patients had reconstruc tion with a double-stranded graft. The mean injury to surgery interval was 9.6 days in 22 patients (acute group) and 22.5 months in 28 patients (chronic group). Objective outcome, which was noted to be more opti mal in the acute group, was better than subjective outcome in either group. Examination revealed 95% of patients treated acutely and 82% of those treated later to have 1 + or less Lachman test result (P < 0.036) and 96% of the acute group and 82% of the chronic group to have an absent pivot shift (P < 0.036). Eighty-eight percent of acutely treated patients had a KT-1000 result of ≤3 mm, as compared to 61% of chronically treated patients (P < 0.001). Loss of range of motion was significantly greater in the acute group (P < 0.018). Using a strict overall rating system, patients recon structed earlier were noted to have a better outcome compared to those after delayed reconstruction (P < 0.021). Cumulative meniscal injury appears to be the most significant contributing factor.

We measured the increases in tibiofemoral motion when lateral structures were sectioned in anterior cru ciate ligament-deficient knees of 20 unembalmed ca daveric whole lower limbs. Motion was measured with a six degrees-of-freedom electrogoniometer. The lateral structures investigated were the iliotibial band and mid- lateral capsule, lateral collateral ligament, and popliteus tendon and the posterolateral capsule.

Cutting the anterolateral structures increased anterior translation and internal rotation, particularly in flexion. Increases in motions were highly variable, reflecting the variation in function in the lateral collateral ligament and posterolateral structures. Cutting the lateral collateral ligament produced small changes in anterior translation and external rotation and larger increases in adduction. Cutting the posterolateral structures produced small increases in external rotation. Large increases in exter nal rotation were found only if the lateral collateral ligament was also sectioned. The posterolateral struc tures act in concert with the lateral collateral ligament in restraining internal and external rotation. External rotation was affected at all flexion angles; internal ro tation was affected mainly in extension.

Our results can be used in the diagnosis of complex knee ligament injuries. Findings of increased anterior translation in both flexion and extension and increased internal rotation at 90° of flexion are consistent with combined injury to the anterior cruciate ligament and the anterolateral structures. The anterior cruciate liga ment-deficient knee with significant posterolateral com promise (posterolateral structures/lateral collateral lig ament) would exhibit larger anterior translation in ex tension than in flexion, increased adduction, and increased external rotation in both flexion and exten sion.

Anterior-posterior knee displacements were measured sequentially with the KT-1000 arthrometer on 84 pa tients after anterior cruciate ligament reconstruction for chronic deficiency. We determined the correlations be tween the initial onset of abnormal displacements (greater than 2.5 mm between limbs) and time from surgery or the phase of rehabilitation.

Group 1 (N = 52) had a bone-patellar tendon-bone allograft and Group 2 (N = 32), an iliotibial band extraar ticular procedure in addition to the allograft. The mean followup was 37 months (range, 23 to 65).

At followup in Group 1, 24 patients (46%) had less than 3 mm of displacement between limbs, 22 (42%) had 3 to 5.5 mm, and 6 (12%) had greater than 5.5 mm. In Group 2, 23 patients (72%) had less than 3 mm of displacement, 8 (25%) had 3 to 5.5 mm, and 1 (3%) had greater than 5.5 mm. The difference between the groups was significant (P < 0.05).

The advanced rehabilitation program of immediate knee motion and early weightbearing, did not result in an increased incidence of abnormal displacements in the early phases. The abnormal displacements typically occurred during the latter two rehabilitation phases (intensive strength training or return to sports). Further, one-third of the abonormal displacement occurred more than 2 years postoperatively.

A 5-year prospective study on the time course of wom en's gymnastics injuries was conducted on a successful NCAA Division I team. Gymnasts recorded injuries on a computer terminal or via computer dot sheets imme diately before each training session, including the in jured body part, the event or activity, and the date of the injury. The definition of injury was "any damaged body part that would interfere with training." Athletes recorded injuries on the 1 st day of onset and subse quently until the injury was healed. The initial onset of injury was considered a new injury. Subsequent rec ords of the injury were considered continuing injury.

Thirty-seven athletes participated through five colle giate seasons. They accounted for 5602 total training exposures with an average of 151.4 exposures per athlete. The analyses showed that gymnasts trained with an injury approximately 71% of the exposures, and a new injury could be expected from a gymnast during approximately 9% of the exposures. The largest number of injuries were of the repetitive stress syn drome type. The time series information showed that total injuries tended to increase until the middle of the competitive season, while new injuries showed promi nent increases during specific training periods and dur ing competition preparation and performance.

To evaluate the fate of patellar tendon autografts in humans, the knees of 23 patients who had undergone anterior cruciate ligament reconstruction were exam ined 3 weeks to 6.5 years postoperatively. Arthroscopy and biopsy were performed on all patients.

The patellar tendon autografts progressed through four stages of ligamentization after reconstruction. The first stage of repopulation occurred during the first 2 months and was evidenced by a viable 3-week speci men with an increasing fibroblast number and active nuclear morphology. Over the next 10 months, the graft went through a stage of rapid remodeling in which the fibroblast count increased markedly, the active nuclear morphology and neovascularity remained increased, and more areas of degeneration were present as the percentage of mature collagen decreased. The third stage or "maturation" stage occurred over the next 2 years and was characterized by a slow decline in the nuclei and the maturation of the collagen matrix. By 3 years the grafts were ligamentous by all histologic criteria examined.

The authors conclude that human autogenous patel lar tendon grafts are viable as early as 3 weeks post operatively and may not go through a necrotic stage. They then progress through a prolonged process of ligamentization that takes as long as 3 years to com plete.

The purposes of this study were to compare operated and nonoperated knees after anterior cruciate ligament reconstruction using the semitendinosus tendon and a polypropylene ligament augmentation device, and to determine the interrelationships among strength, knee stability, and current activity levels. Isokinetic tests for knee flexion (prone position) and extension (sitting po sition) strength during concentric-eccentric muscle ac tion cycles were completed at 60 and 180 deg/sec angular velocities, and passive anterior displacement were determined for 15 male and 15 female patients (mean age, 27 ± 8 years; mean time since surgery, 21 ± 3 months). With the exception of eccentric muscle actions during knee extension, peak torque and work done were significantly greater on the nonoperated leg (P < 0.05). Passive anterior displacement was signifi cantly greater in the operated than the nonoperated knee (P < 0.01). Strength measurements tended to be modestly related to current activity level ( R > 0.40 in 24 of 32 correlations; P < 0.05), whereas anterior displacement was not related to current activity level (R = -0.19, operated knee; R = - 0.09, nonoperated knee; P > 0.05). Greater emphasis should be directed toward strengthening the knee flexors and knee exten sors after this surgery. Although joint-specific tests (completed actively via isokinetic dynameter) are more related to activity levels than are knee laxity tests (completed passively via knee arthrometer), neither test should be relied on as the only predictor of activity level in this patient population.

In this study we sought both to quantify the forces that result in anterior cruciate ligament graft impingement and the amount of roofplasty necessary to prevent it. The perpendicular force of the intercondylar roof against an anterior cruciate ligament graft was meas ured in seven fresh-frozen cadaveric knees. Two tibial hole placements were evaluated: an anterior/eccentric hole (26.6% ± 3.1% of the sagittal depth) and a cus tomized hole aligned 4 to 5 mm posterior and parallel to the slope of the intercondylar roof in the extended knee (42.0% ± 2.6% of the sagittal depth). A transducer that measured the contact force with the graft was implanted in the roof. An extensive roofplasty was performed so that the sensor would bear all of the roof force. Graft tension was also measured. Extension moments were applied to 20 N-m with a six degree of freedom load application system. Load cycles were repeated with the roof force sensor backed out in 0.8 mm increments. The sensor backout represented a corresponding amount of bone removal in a roofplasty. The flexion angle at roof-graft contact was consist ently greater using the anterior tibial hole than the customized one. This held true for all increments of sensor backout. With the anterior hole, the roof sensor (no backout) contacted the graft at 12.8° ± 6.7° of flexion, whereas the customized hole resulted in con tact at 4.1° ± 4.2° (P = 0.020). With zero impingement defined as no contact between the roof and the graft throughout the range of motion, the anterior hole re quired 4.6 ± 1.0 mm of roof removal, and the custom ized hole required 1.3 ± 1.1 mm of roof removal (P ≤ 0.0001).

The effect of tibial and femoral attachment site on the length change and force of an anterior cruciate ligament graft during unloaded flexion in eight cadaver speci mens was examined. Two tibial sites (anteromedial and central portion of the anterior cruciate ligament attach ment) and three femoral sites (anterior and central portions of the anterior cruciate ligament attachment, and over-the-top) were evaluated. Graft length changes between all combinations of attachment sites were measured from full extension to 150° of passive flexion at 15° intervals using the displacement of a 2-mm inextensible cord. The anterior cruciate ligament was then reconstructed using a Kennedy Ligament Aug mentation Device, and graft forces at the same angles of passive flexion were measured with a buckle trans ducer.

Graft length change and force were more affected by the femoral attachment site than the tibial site. There was a close correlation between length change and force measurements in flexion, but not near extension. The pattern of force and length change versus flexion angle for a given combination of attachment sites some times varied over the knees tested. Our results suggest that intraoperative isometry measurements are worth while for indicating an overloaded graft in flexion; how ever, length changes near extension may not ade quately reflect graft force, creating the possibility that a graft may be more highly loaded than realized.

To investigate the effects of postoperative immobiliza tion and limited motion on reconstructed anterior cru ciate ligaments, 28 rabbits received an anterior cruciate ligament reconstruction using autogenous Achilles ten don and were then divided into three groups: fully immobilized, 4 weeks immobilized, and limited motion. Two rabbits from each group were evaluated macro scopically, histologically, and microangiographically at 4-week intervals until 12 weeks postoperatively. An additional six rabbits in the 4 weeks immobilized and limited motion groups were studied biomechanically at 12 weeks postoperatively.

Macroscopically, both immobilized groups showed more proliferation of the infrapatellar fat pad, which was adherent to the reconstructed anterior cruciate liga ment. Histology revealed more rapid regeneration of reconstructed anterior cruciate ligaments in the limited motion group, with no findings of necrosis in the mid- substance. Microangiography indicated faster normali zation of vascularity in the limited motion group. The biomechanical study showed no significant difference in laxity between the 4 weeks immobilized and limited motion groups. The graft stiffness and maximum load to failure were greater for the limited motion group, although the increase was not statistically significant. The histologic and microangiographic results from the limited number of animals in this study support limited postoperative motion in the anterior cruciate ligament reconstructed knee. However, there were no differ ences in terms of the biomechanical parameters at 12 weeks postoperatively between the immobilized and limited motion treatment modes.

A prospective study was established to record the patterns of injury incurred by all members of a women's college gymnastics team. Twenty-six women were fol lowed over a 4-year period (53 gymnast seasons) from 1983 to 1987. To identify which injuries resulted in persisting impairment, these same athletes were con tacted again 3 years later. The 26 athletes sustained 106 injuries. Sixty (57%) of these were of acute onset and were related to an identifiable gymnastics event. The remaining 46 (43%) were of gradual onset or overuse injuries. For the follow-up phase, 22 of the 26 women were contacted from 10 to 70 months (38.5 average) after completion of their gymnastics careers. Forty-five percent of the injuries recorded in their com petitive years still bothered them at the time of followup, especially low back, ankle, great toe, shoulder, and knee injuries. Athletic and recreational activity exacer bated the complaints. Twenty-nine percent felt that their sports activity level was now limited. Forty-six percent felt that their injury was at less than full recovery, yet most felt that they were capable of strenuous physical activity and continued to be active despite complaints such as pain and stiffness.