The American Journal of Sports Medicine

The human knee joint represents a complex biome chanical system of which the menisci are an integral component. At present, little data exists describing the meniscal kinematics of the intact knee. Accordingly, a three-dimensional reconstruction magnetic resonance image model was used to explore this issue.

Five fresh cadaveric knees were examined by mag netic resonance imaging throughout a full range of motion at 10° intervals. Computer three-dimensional images of the menisci were generated and evaluated for anteroposterior excursion and deformation. During flexion, the posterior excursion of the medial meniscus was 5.1 mm, while that of the lateral meniscus was 11.2 mm. The anterior horn segments were shown to be more mobile than the posterior horn segments bilat erally.

Prior limitations of meniscal kinematic assessment may be overcome with advanced imaging techniques such as magnetic resonance imaging and three-dimen sional reconstruction. The menisci are highly mobile and easily deformed structures within the intact, cadav eric knee. This imaging technique may prove useful in the elucidation of meniscal dynamics. In the future, similar techniques may be applied clinically to aid in the diagnosis of joint dysfunction.

The structural properties of 27 pairs of human cadaver knees were evaluated. Specimens were equally divided into three groups of nine pairs each based on age: younger (22 to 35 years), middle (40 to 50 years), and older (60 to 97 years). Anterior-posterior displacement tests with the intact knee at 30° and 90° of flexion revealed a significant effect of knee flexion angle, but not of specimen age. Tensile tests of the femur-ACL- tibia complex were performed at 30° of knee flexion with the ACL aligned vertically along the direction of applied tensile load. One knee from each pair was oriented anatomically (anatomical orientation), and the contralateral knee was oriented with the tibia aligned vertically (tibial orientation). Structural properties of the femur-ACL-tibia complex, as represented by the linear stiffness, ultimate load, and energy absorbed, were found to decrease significantly with specimen age and were also found to have higher values in specimens tested in the anatomical orientation. In the younger specimens, linear stiffness (242 ± 28 N/mm) and ulti mate load (2160 ± 157 N) values found when the femur- ACL-tibia complex was tested in the anatomical orien tation were higher than those reported previously in the literature. These values provide new baseline data for the design and selection of grafts for ACL replacement in an attempt to reproduce normal knee kinematics.

This paper reviews recent research on functional knee bracing. Research is categorized by subject, approach, or technique. The authors conclude that, while there is a good deal of excellent research available, there is little data to assist the clinician in selecting an orthosis for a specific application. The authors recommend that future investigations address the physiologic aspects of functional knee bracing and that brace manufacturers assume more responsibility in the validation of both existing and future brace designs.

A review is presented here of 36 cases, seen since 1980, of acute Grade III (unstable) sports-related sprains of the thumb metacarpophalangeal joint. In all cases, the injury involved the ulnar collateral ligament. A Stener lesion was present in 97% of cases. Followup was from 2.0 to 8.5 years, the average being 3.9 years. All of the patients underwent repeat examination and radiography at followup.

The first seven patients were treated by "traditional" pull-out suture and K-wire fixation, put into a cast for 4 weeks, and then gradually mobilized over 4 additional weeks. Thereafter, a "new method" was used. Avulsed ulnar collateral ligament stumps were sutured to the tendinous insertion of the adductor pollicis or to a soft tissue remnant using strong suture material. Large bony avulsions were pinned; small fragments were excised and the ligament was repaired. This latter method of repair was quite strong and allowed rapid mobilization: only 2 weeks in a cast, then a hand- mounted thumb spica orthosis was used while therapy progressed.

Of the patients treated with the new method, 84% had excellent results and, overall, were able to return to sports sooner than patients treated with the tradi tional method. Pain, stability, and strength were cor rected equally between groups; however, strength was restored more rapidly in the new method group. Range of motion was reduced equally in both groups.

Conclusion: Solid repair of complete ulnar collateral ligament avulsions, consisting of suturing the avulsed portion to the adductor pollicis insertion using strong suture material, combined with early hand therapy fa cilitated by the use of a removable hand-mounted thumb spica orthosis, is safe and allows a faster return to sports than the traditional method of repair.

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

Fifty primary ACL repairs using the Marshall multiple suture technique were analyzed. The average age at surgery was 23 years (range, 15 to 56), with 76% under the age of 30. The average followup was 61.3 months (range, 48 to 86). The average time from injury to surgery was 7 days (range, 1 to 18). Eighty percent of the injuries were sports-related with football and skiing predominating. Thirty-eight percent were "isolated" ACL tears, and 62% had associated injuries. There was a 46% incidence of meniscal tear with 59% of the meniscal tears being repaired.

The postoperative evaluation included a multifactorial analysis correlating 43 variables including subjective, objective, radiographic, and KT-1000 data. The Hospi tal for Special Surgery Knee Diagnostic Score, a clinical objective score based on the postoperative Lachman and pivot shift examination, a KT-1000 arthrometer data score, and an overall combined assessment score were determined. The results showed 59% excellent, 18% good, 14% fair, and 8% poor.

The Lachman test was diagnostic in all cases. The quality of ACL tissue at repair was rated excellent or good in 62% of the cases. Four patterns of ACL tears were distinguished by the location of the tear. Football injury, younger age, increased preoperative pivot shift, midsubstance Type IV tear, and return of full motion correlated with poor postoperative results. Increasing age, tight jointedness, Type I tears, and a 5° flexion contracture correlated with good postoperative results.

Twenty-eight goats underwent ACL reconstruction with freeze-dried bone-patellar tendon-bone allografts in one knee, the opposite knee serving as a control. One group of 16 knees was evaluated, in groups of four, at 6, 12, 26, and 52 weeks by histologic and vascular injection techniques. The other group of 12 knees was evaluated in two groups of six at 26 and 52 weeks by morpholog ical and biomechanical techniques of analysis.

Within the first 12 weeks these allografts were revas cularized ; in the first 26 weeks they had matured to resemble normal connective tissue. Graft stiffness was 29% of the control value and maximum force to failure was 43% of the control value.

The results of this study indicated that freeze-dried bone-patellar tendon-bone allografts are biomechani cally and biologically similar to patellar tendon auto- grafts.

Many exercises are used to strengthen the glenohu meral muscles, but there have been limited studies to evaluate the exercises. Thus, the purpose of this study was to decide how the muscles responsible for humeral motion can best be exercised in a rehabilitation program for the throwing athlete. Dynamic, fine wire, intramus cular electromyography was carried out in 15 normal male volunteers performing 17 shoulder exercises de rived from a shoulder rehabilitation program used by professional baseball clubs. The four rotator cuff mus cles were studied, as well as other positioners of the humerus, including the pectoralis major, latissimus dorsi, and three portions of the deltoid. The electro myographic activity was synchronized with cinematog raphy and averaged over 30° arcs of motion. An exer cise was considered to be a significant challenge for a muscle if it generated at least 50% of its predetermined maximum contraction over three consecutive arcs (i.e., a 90° range). Four exercises were consistently found to be among the most challenging exercises for every muscle. These shoulder exercises consisted of 1) ele vation in the scapular plane with thumbs down, 2) flexion, 3) horizontal abduction with arms externally rotated, and 4) press-up. This study documents that the minimum for an effective and succinct rehabilitation protocol for the glenohumeral muscles would include these exercises.

We registered all new injuries among 496 male youth soccer players, aged 12 to 18 years, during the course of one year. The incidence of injury was 3.7 injuries per 1000 hours of soccer per player. The incidence in creased with age, and at the higher ages within the youth players, approached the incidence rate of senior players (age ≥18 years).

Seventy percent of the injuries were located in the lower extremities, particularly the knee (26%) and ankle (23%). Back pain occurred in 14% of players. Fractures, which accounted for 4% of injuries, were most often in the upper extremities. We conclude that youth soccer is a relatively low-risk sport with an injury pattern that differs slightly from that of senior players.

This study was designed to analyze how anterior tibial tunnel placement can result in graft impingement by the intercondylar roof. The relationship of the ACL to the intercondylar roof was studied using magnetic reso nance scans. An attempt was made to predict the amount of bone that may need to be removed from the intercondylar roof to prevent impingement on a 10 mm thick ACL graft.

Magnetic resonance scans of 19 normal ACLs were analyzed. The amount of bone removal required to correct roof impingement was determined for a graft placed either eccentrically or centrally within the ACL insertion, and within the bulk of the normal ACL fibers. An eccentric tibial tunnel placement required approxi mately 5 to 6 mm and a central placement required 2 to 3 mm of bone removal from the intercondylar roof to prevent impingement. Placing the graft within the bulk of the ACL fibers, just 3 mm posterior to the center of the ACL insertion, required little bone resection to prevent impingement.

To prevent ACL graft impingement, roofplasties need to be performed in both acute and chronic ACL recon structions if the presently accepted locations for posi tioning the tibial tunnel are used. A more anteriorly placed tibial tunnel requires more bone removal to prevent roof impingement than a more posteriorly po sitioned tibial tunnel.

We analyzed the results of knee manipulations in 42 knees that had persistent flexion or extension deficits after intraarticular ACL reconstructions. All manipula tions were done under a spinal or general anesthetic and, in 10 cases, arthroscopic debridement of adhe sions also was performed. The average time from re construction to manipulation was 7 months (range, 3 to 14 months) and the average followup was 26 months (range, 6 to 56 months). At manipulation, average flex ion was increased from 95° to 136° and average ex tension from 11° to 3°. In no case was motion gained at the expense of joint stability and, at final followup, average flexion and extension were 127° and 4°, re spectively. The final range of motion achieved was not affected by the time to manipulation, severity of pre manipulation flexion deficit, or concomitant arthro scopic debridement of adhesions. However, knees with premanipulation extension deficits of ≥15° achieved significantly less final extension than knees with lesser premanipulation deficits. Overall, manipulations were a safe and effective method for improving both flexion and extension in 86% of the knees that had restricted motion after ACL reconstructions.

Golf is an activity generally stressful to the hands and wrists and particularly can produce increasing symp toms in players with underlying problems such as hand and wrist arthritis or tendinitis. The purpose of this study was to quantitate wrist motion and club head/ ball impact force in subjects with pathologic conditions of the hand, wrist, or forearm, within a laboratory environment. A regular straight-handled golf club was compared to a new BioCurve handle design that has a 19° ulnar bend. We measured and compared the effect of the two grips on wrist motion, club head velocity, ball impact force, ball impact location, and isometric torsional strength in 20 subjects who had a variety of upper extremity disorders. This data was then com pared to data collected in an identical fashion from golfers without such conditions.

The results of our study show that there were no differences related to club handle design on impact force or impact location, club head velocity, or club head path and face angle. Wrist kinematic differences were minimal between handle designs. The differences that were significant (P < 0.05) centered around the decreased ulnar deviation of the left hand that resulted when subjects used the BioCurve handle design, which also allowed greater resistance to torque than the straight grip club. In addition to collecting objective data, we asked subjects for their opinions of the two grips. As a whole, the normal group and the group with pathologic conditions noted more comfort, improved grip, and less shock transmission with the BioCurve handle.

In this study we reviewed ankle sprains in a professional football team over a 6 year period. Fifteen players who sustained syndesmotic ankle sprains were compared with 28 players who sustained significant lateral ankle sprains. Players with syndesmotic sprains missed sig nificantly more games and practices and they received substantially more treatments than players with lateral ankle sprains. Physical examination findings, results of radiographic evaluations, and etiologic factors are dis cussed. The external rotation stress test, a clinical method for diagnosis of this type of sprain at the time of injury, is described.

Results of this study clearly demonstrate a prolonged recovery time for syndesmotic ankle sprains. Physi cians and trainers who are aware of this injury can differentially diagnose these two types of sprains in the early postinjury period by the method described.

A 3 year study of 117 quadriceps contusions in West Point cadets was undertaken to document the effec tiveness of a three-phased therapy program to return these young athletes to full activity with a normal knee range of motion and without recurrence of injury. The treatment protocol of this study was modeled after the 1973 West Point study of Jackson and Feagin with two major changes: 1) resting the injured leg in flexion (versus extension) and 2) emphasizing early flexion exercises (versus extension). Classification of contu sions was based on knee range of motion at 12 to 24 hours after the injury (mild, >90°; moderate, 45° to 90°; severe, <45°). The average disability time was 13 days for mild, 19 days for moderate, and 21 days for severe contusions. Myositis ossificans developed in 9% of cadets and was associated with five risk factors (knee motion less than 120°, injury occurring during football, previous quadriceps injury, delay in treatment greater than 3 days, and ipsilateral knee effusion).

This study analyzed forces in the tibiofemoral and pa tellofemoral joints during isokinetic exercise using an analytical biomechanical model. The results show that isokinetic exercise can produce large loads on these joints, especially during extension exercises. The tibio femoral compressive force (4.0 body weight) is approx imately equal to that obtained during walking but it occurs at 55° of knee flexion. Anterior shear forces (resisting force to anterior drawer) exist during exten sion exercise at less than 40° of knee flexion, with a maximum of 0.3 body weight. Posterior shear forces (resisting force to posterior drawer) exist during exten sion exercise at knee joint angles greater than 40° and during the flexion portion of isokinetic exercise. The maximum posterior shear force is 1.7 body weight. The patellofemoral joint can encounter loads as high as 5.1 body weight which are 10 times higher than during straight leg raises. These results suggest that isokinetic exercise should be used cautiously in patients with knee lesions.

We have reported three cases of fatigue fracture of the ulna in male pitchers of fast-pitch softball. To elucidate the etiology of injury, we first selected three healthy male and three healthy female pitchers from a well- trained college team and analyzed their forearm move ment by high-speed cinematography. This showed slight flexion of the elbow joints during wind-up motion, dorsal flexion of the hand joints upon releasing the ball, and extreme pronation of the forearms during the fol low-through. We then took 8 mm CT scanning sections of the forearms. Using these images, we investigated shapes and areas of cross-sections of the ulna and its cortical and cancellous bones from the elbow to the hand joints. Our results reveal that the shapes of the sections are significantly different from circles at around the center of the ulna, and the cross-sectional areas are smaller in the middle one-third of the ulna than in other parts. These observations imply that fatigue frac tures of the ulna in pitchers of fast-pitch softball must be torsionally induced, tending to occur at the middle one-third of the bone.