The American Journal of Sports Medicine

Decisions made before reconstruction of the ACL in clude patient selection, choice of operative procedure, and selection of proper reconstructive material. Re search in the use of allograft material for reconstructive grafts is of great interest for many reasons, including the advantage of not violating the patient's normal anatomy for donor tissue. A group of eight patients who received arthroscopically inserted freeze-dried bone-patellar tendon-bone allograft tissue for ACL re construction were selected for a prospective study. These patients were matched against a group of four autograft controls.

Immunologically, the lymphocyte blast transformation test was used to evaluate the host reaction to implanted donor graft. Lymphocytes drawn from each patient were tested for their reaction against a panel of human allograft tendon and goat xenograft tendon homoge nates. A stimulation index of greater than 3 was con sidered a positive reaction. It was hypothesized that a consistent lack of antigenicity would be observed with allograft extracts and that an antigenic reaction would be observed with the xenograft extracts.

Six patients (75%) showed an immunologic reaction to the goat xenograft, and four patients (50%) showed an immunologic reaction to at least one human allograft test cell after allograft insertion. One patient had such an intense clinical immunologic response that she re quired removal of the allograft. All four of the autograft controls had a nonimmunogenic response to testing, as had been expected. Although the numbers of this study are small, it is important to point out that an immunologic response to freeze-dried allograft tendon appears to be occurring, in contrast to previous re search in animals.

A prospective clinical study used joint scintigraphy to investigate conservative treatment of juvenile osteo chondritis dissecans (JOCD) of the femoral condyle. The predictive value of scintigraphic evaluation and various parameters (age at onset, sex, location and size of lesion) were analyzed. Over a 10 year period, the senior author followed 92 knees in 76 patients, 60 of whom were male and 16 female (11 and 5 bilaterals, respectively). All patients were participants in athletics or exercise programs.

All patients had orthopaedic assessment, roentgen ographic studies (AP, lateral, and tunnel views), 99m- Technetium phosphate compound joint scintigraphy, and instruction in a symptom-free existence (with all athletic activity proscribed). Patients were reevaluated and scanned every 8 weeks. No casts or braces were used, although crutches were sometimes necessary to maintain symptom-free levels.

Based on specific indications for failure of conserva tive treatment, 50% of these patients failed and under went surgery. Of the 92 knees, 52 were successfully treated conservatively, while 40 failed. Average fol lowup was 4.2 years. Average age at onset was 12.5 years; the success group averaged 12.1 years and the failure group 13.0 years. The average lesion size was 363.2 mm², with 309.5 mm² in the success group and 436.0 mm² in the failure group. Parameters of location, sex, and scan classification were not statistically signif icant as predictive factors.

Previous studies have compared the torque production of the knee flexors and extensors and developed a "hamstring-quadricep" ratio. Collectively, these studies indicate that the ratio of strength between the knee flexors and extensors is a function of test speed, with the ratio increasing at the faster test speeds. Unfortu nately, these studies have employed the peak torque isokinetic method for making measurements. This tech nique suffers from a number of problems that are biomechanical and physiological in nature. Conse quently, in this study, we employed comparisons of the in vivo force-velocity relationship using an angle-specific method and a gravitational correction factor to more accurately determine flexor-extensor ratios and to bet ter describe any variations occurring as a function of test speed. Nine male subjects volunteered to partici pate in this study. Each of the subjects participated in two test sessions. Subjects were tested at six angular velocities of 0, 48, 96, 144, 192, 240 deg/sec. At these respective test speeds, the mean flexor torques were 95.0, 94.8, 84.1, 66.2, 56.2, and 49.2 Nm, respectively. The corresponding values for the knee extensors were 252.2, 246.5, 220.7, 184.5, 161.9, and 146.4 Nm. Normalization of these torque-velocity relationships demonstrated that the in vivo force-velocity relation ships of the two muscle groups are similar at slow speeds, but become disparate at higher velocities. When examining flexor-extensor torque ratios at the various test speeds, it was found that there were significant differences (P < 0.01). The mean values for the flexors expressed as a percent of knee extensor torque were 37.5%, 38.2%, 38.2%, 35.9%, 34.5%, and 33.4% at speeds of 0, 48, 96, 144, 192, and 240 deg/ sec, respectively.

A 1 year prospective study was done to develop an accident-prone and overuse-prone profile of young ath letes. A group of 185 freshman physical education students (118 males; 67 females) of the same age (18.3 ± 0.5 years) trained under the same conditions and were exposed to similar extrinsic risk factors.

Using a descriptive statistical technique, an analysis of correspondence, the complex interrelation between the criterium variables (acute injuries and overuse inju ries) and the predictor variables (intrinsic risk factors; physical characteristics—antropometric data, physical fitness parameters, flexibility aspects and malalignment of the lower extremities; and psychological factors— 16 personality traits) was estimated for males and females separately.

Although dynamic strength seems to be an important risk factor in acute injuries, sports accidents must be seen in relation to psychological factors. However, the overuse-prone profile is mainly based on physical traits: a combination of muscle weakness, ligamentous laxity, and muscle tightness predisposes to stress injuries. In addition, these overuse effects are intensified by large body weight and length, a high explosive strength, and malalignment of the lower limbs. Nevertheless, it has to be kept in mind that psychosomatic factors play a role in how one experiences these overuse phenomena.

Twenty-two cases of occult intraosseous fracture in the region of the knee are presented. Occult intraos seous fractures have been incidentally detected in the magnetic resonance (MR) evaluation of the knee in the setting of a recent physical injury and normal radio graphic studies. There is no unique mechanism of in jury, but occult intraosseous fracture presumably re sults from direct impaction or axial overloading. MR shows speckled or band-like areas of low signal in the intramedullary space of the epiphyses, and occasion ally, the adjacent metaphyses. In most cases, T2- weighted images show high signal in corresponding regions of variable size. The relative extent of high signal findings is shown to vary significantly with the age of injury. Individual variability within groups, how ever, precludes the actual prediction of lesion age on the basis of the MR appearance. Our observations provide indirect evidence that the findings on T2- weighted images resolve earlier than the corresponding findings on T1-weighted or proton density images. The primary differential diagnosis in cases of occult intraos seous fracture is stress fracture. The diagnosis of oc cult intraosseous fracture may be important in explain ing persistent pain after injury in otherwise normal knees.

Development of a new testing machine, which stabilizes the pelvis, allowed us to evaluate the lumbar extensor muscles before and after training. Fifteen healthy sub jects (29.1 ± 8 years of age) trained 1 day per week for 10 weeks and 10 healthy subjects (33.7 ± 16 years of age) acted as controls. Training consisted of 6 to 15 repetitions of full range of motion variable resistance lumbar extension exercise to volitional fatigue and periodic maximal isometric contractions taken at seven angles through a full range of motion. Before and after the 10 week training period, subjects completed a maximum isometric strength test at seven angles through a 72° range of motion (0°, 12°, 24°, 36°, 48°, 60°, and 72° of lumbar flexion). The training group significantly improved in lumbar extension strength at all angles (P ≤ 0.01). The result at 0° (full extension) showed an increase from 180.0 ± 25 Nm to 364.1 ± 43 Nm (+102%) and at 72° (full flexion) from 427.4 ± 44.1 to 607.4 ± 68 (+42%) Nm. Results from the control group showed no change (P ≥ 0.05). The mag nitude of gain shown by the training group reflects the low initial trained state of the lumbar extensor muscles. These data indicate that when the lumbar area is iso lated through pelvic stabilization, the isolated lumbar extensor muscles show an abnormally large potential for strength increase.

The Bankart repair for chronic anterior shoulder insta bility effectively addresses the pathologic components responsible for repeated dislocation or subluxation. However, contrary to popular belief, the Bankart repair does not precisely restore the premorbid anatomy. The capsule is reattached to the boney rim of the anteroin ferior glenoid deep to and lateral to the torn cartilagen ous labrum, thus excluding the labrum from the joint anteriorly. This was demonstrated by cross-sectional cadaver dissections performed to illustrate this complex surgical anatomy to orthopaedic residents in training. In addition, when correlated with double-contrast com puterized axial tomography, we noted five predominant patterns of anatomical lesions which by common use have been collectively termed the "Bankart lesion." These are: 1) the rare "classic" Bankart lesion in which the cartilagenous labrum and capsular origin are torn from the glenoid rim; 2) the capsule stripped from the scapular neck and the labrum detached from the gle noid rim remaining fixed to the overlying capsule; 3) the capsule stripped from the scapular neck and the labrum separated from the glenoid rim, but separately; 4) the labrum abraded away and no longer radiographically detectable; and 5) glenoid rim fracture.

Injuries of the posteromedial corner of the knee joint were evaluated using the results of clinical, arthro graphic, and arthroscopic examinations in 137 sur gically treated patients (137 knees) with injuries of the ACL (acute in 61, chronic in 76). The accuracy of each diagnosis was confirmed by determining the site of the injury during the arthrotomy.

A tear of the posteromedial corner of the medial meniscus was present in 40 patients, and an accurate diagnosis was made in 29 patients by clinical exami nation, in all 40 patients by arthrography, and in 38 patients by arthroscopy.

Injury of the posterior oblique ligament was noted in 37 patients, and an accurate diagnosis was made in 15 patients by clinical examination, in 35 patients by ar thrography, and in 8 patients by arthroscopy. Lesions of the posterior oblique ligament which were not de tected in the arthroscopic examination alone were either rupture at the attachment to the femur or longi tudinal tears in the meniscofemoral or meniscotibial portion.

The results revealed that arthrography is an important means of evaluation in the diagnosis of injuries of the posteromedial corner of the knee joint.

Electromyographic (EMG) activity of selected shoulder girdle muscles was analyzed during voluntary posterior subluxation of the glenohumeral joint in four subjects. Although there was a great deal of variation in the muscle activation patterns during subluxation, subjects either pushed the humeral head backwards with the anterior muscles (deltoid, biceps) or pulled the humeral head backwards with the infraspinatus and/or posterior deltoid. In all cases, inhibition of the scapular rotators and winging of the scapula accompanied this maneu ver. The method used in this study is presented as an objective technique for quantifying EMG activity during subluxation and relocation phases of shoulder instabil ity.

The Stryker knee arthrometer was assessed in the environment of a nonspecialized National Health Serv ice clinic by junior doctors in training. Forty percent of proven anterior cruciate deficient knees had a meas ured anterior excursion of 2 mm or less compared with the normal side under the same circumstances. Twenty percent of normal knees tested showed more than this variation between knees when different observers were compared and also when the same observers were compared at three week intervals. There is thus a question about the use of this machine in a general orthopaedic clinic with different observers.

A selected group of 23 patients underwent surgery for iliotibial band friction syndrome. Among the patients presenting with this exertional pain syndrome were runners, football players, and cyclists. Diagnosis was clinical since radiographs were negative and an ultra sound examination was positive in only one case, show ing an aberrant picture around the lateral femoral epi condyle. Although conservative treatment is effective in most cases, an alternative is needed for patients with complaints that are resistant to conservative means. Surgery was done with the knee held in 60° of flexion and consisted of a limited resection of a small triangular piece at the posterior part of the iliotibial band covering the lateral femoral epicondyle. The uniform good re sults, low morbidity, and quick return to sports dem onstrate that this type of surgery offers a solution for selected cases of failed prolonged conservative treat ment.

Acute brachial neuropathy is an uncommon etiology of shoulder pain and disability. It can, however, present in association with athletic activity and therefore must be included in the differential diagnosis of athletes with such symptomatology. Findings that should alert the examiner to the possible presence of acute brachial neuropathy include 1) onset with noncontact as well as contact sports, 2) rather acute onset of pain without specific inciting trauma, 3) persistent, often severe pain that continues despite rest, 4) patchy brachial plexus and/or peripheral nerve involvement, and, 5) dominant arm predominance of symptoms and signs.

Electromyography and nerve conduction studies often can confirm the diagnosis. Treatment begins with rest and continues through a rehabilitation phase. Fol lowup of athletes with acute brachial neuropathy dis closes that weakness may persist in the affected mus cles. Absolute strength parity may be difficult to achieve, so permission to participate in athletics must be given on a case by case basis.

Eleven patients (two male, nine female) were treated with epidural sympathetic blockade for reflex sympa thetic imbalance, an incomplete manifestation of reflex sympathetic dystrophy. Each had developed severe pain, sensitivity, and disability disproportionate to as sociated trauma. One patient injured an ankle, and the remaining 10 patients one or both knees (12 knees). Seven patients had undergone previous surgery. All but one had a favorable response to initial blockade. This individual eventually failed treatment despite surgical sympathectomy. Seven have required readministration of a block for clinical relapse. Mean followup was 22 months (range, 10 to 41 months). Five underwent ex tensive psychological testing. All have required adjunc tive forms of therapy including physical therapy, trans cutaneous electrical nerve stimulation (TENS), antiin flammatory or other nonnarcotic agents. Recovery is typically prolonged, particularly if the diagnosis is de layed. Close attention to, and therefore prevention of, situations that trigger its recurrence is essential for successful rehabilitation.

A model of metatarsal mechanics has been proposed as a link between the high incidence of second and third metatarsal stress fractures and the large stresses measured beneath the second and third metatarsal heads during distance running. Eight discrete piezo electric vertical stress transducers were used to record the forefoot stresses of 21 male distance runners. Based upon load bearing area estimates derived from footprints, plantar forces were estimated. Highest force was estimated beneath the second and first metatarsal head (341.1 N and 279.1 N, respectively). Considering the toe as a hinged cantilever and the metatarsal as a proximally attached rigid cantilever allowed estimation of metatarsal midshaft bending strain, shear, and axial forces. Bending strain was estimated to be greatest in the second metatarsal (6662 με), a value 6.9 times greater than estimated first metatarsal strain. Predicted third, fourth, and fifth metatarsal strains ranged be tween 4832 and 5241 με. Shear force estimates were also greatest in the second metatarsal (203.0 N). Axial forces were highest in the first metatarsal (593.2 N) due to large hallux forces in relationship to the remain ing toes. Although a first order model, these data highlight the structural demands placed upon the sec ond metatarsal, a location of high metatarsal stress fracture incidence during distance running.

A questionnaire was mailed to 600 of 657 finishers in the Seafair Triathlon (July 20, 1986); 45% of those polled returned the questionnaire. Over the preceding year, 49% of the respondents suffered a training-re lated injury serious enough to cause them to stop training for at least 1 day, seek medical care, or take medicine. Seventy percent of the injuries were due solely or partly to running. The knee, shoulder, and ankle were most frequently affected. Female triathletes and those more than 40 years of age showed a similar injury incidence and distribution. Elite triathletes aver aged more miles per week in each sport than the athletes as a whole and showed a higher incidence of injury (60%), although this was not a significant differ ence. Higher weekly swimming, cycling, and running mileages did not lead to a higher incidence of injury. The likelihood of injury was independent of age, sex, body mass index, mileage per week, or other training factors evaluated in the study.

A 4 year prospective study (1982 to 1985) of high school varsity football injuries from the four Peoria high school football teams was undertaken. Two hundred fifty-one injuries were recorded among a player popu lation of 598, resulting in an injury rate of 42.1 % per 100 players. All of the players followed a prescribed preseason summer conditioning program that was en dorsed by the Illinois High School Athletic Association.

The injuries were recorded on an athletic injury profile and entered into a computer for data analysis and retrieval. The injury distribution by player position showed that halfbacks, tackles, linebackers, and guards had a higher risk of injury than other positions. The knee was the body part injured most frequently (20.3%). A matrix of injuries to halfbacks was set up to examine the relationship of body part injured to type of play, time of injury, and activity during injury. An an thropometric study using the Quetelet index did not reveal any correlation between injury and body size when the injured players were compared with the non- injured players. Experience since 1969 has taught us many of the errors and pitfalls involved in injury sur veillance. Strict adherence to recording of data will ensure an accurate and useful injury surveillance pro gram.

A two-part study was performed to determine the ef fects of high doses of anabolic steroids on weight, appetite, and organ histology. Initially, 30 white Wistar rats, 15 males and 15 females, were treated weekly with either 0.52 cc of physiologic saline or nandrolone decanoate. After 6 weeks, female treated and control rats had comparable weight gains, but male treated rats were significantly lighter than controls. Rats were sacrificed and organs dissected for histologic prepara tion. Treated male livers had less lipid than control males. The uteri of treated females displayed abnormal vacuolization, stromal edema, and peliosis.

In Part 11, 12 male rats, 6 treated and 6 control, were given the drug or saline in a manner identical to that in Part I. Treated rats had lower weights from Weeks 1 through 6 and ate less than controls. Upon sacrifice, treated rats' kidneys were heavier, and testes and liver were lighter compared to controls. Roentgenographic studies of tibias from Parts I and II showed no significant differences in tibial length or height of growth plate between treated and control groups. In summary, when anabolic steroid use is studied in the rat model, numer ous pathological and anatomical changes occur.

This report shows that although 95.4% of players in the U.S. Rugby Team believed mouthguards provided local protection, only half wore a mouthguard. How ever, 90.9% of mouthguard wearers would not play without their mouthguard and 54.5% believed wearing mouthguards should be made compulsory in rugby football. Approximately one-third of the team had sus tained an orofacial injury that required treatment and none were wearing a mouthguard at the time of injury. These and other results are compared to an identical study of the 1984 Australian Rugby Team, the only previous such study reported.

The following abstracts are of papers presented at the 6th Congress of the International Society of the Knee. The president of the Society and the Congress was Lamberto Perugia, MD, Rome, Italy.