The American Journal of Sports Medicine

The purpose of this study was to investigate the bio mechanical behavior of human anterior talofibular and calcaneofibular ligaments, as well as peroneus brevis, split peroneus brevis, and toe extensor tendon grafts. This article represents the first published data compar ing the most frequently injured ankle ligaments to the most commonly used autogenous reconstructive grafts.

Twenty fresh human ankles provided the bone-liga ment-bone and tendon graft specimens for biomechan ical testing on a Minneapolis Testing System. Protocol consisted of cyclic loading at physiologic deflections, followed by several load-deflection tests at varying velocities, followed by a final extremely rapid load to failure test.

The load-deflection data for all ligaments and tendons demonstrated nonlinearity and strain rate dependence. The maximum load to failure for the anterior talofibular ligament was the lowest of all specimens tested, while its strain to failure was the highest. The loads to failure of the peroneus brevis and split peroneus tendons were signficantly greater than the anterior talofibular ligament and approximately equal to the calcaneofibular liga ment. Strains to failure for all tendons were significantly less than ligament strains.

The high strain to failure of the anterior talofibular ligament demonstrates its physiologic function of allow ing increased ankle plantar flexion-internal rotation, while its low load to failure shows its propensity for injury. The greater strength of the tendon grafts ex plains the success of most reconstructive procedures in reestablishing stability in chronic ankle sprains; at the same time, the data presented suggest that those surgical procedures sacrificing the entire peroneus brevis tendon are unnecessary. Finally, the greater stiffness of the tendon grafts may cause postoperative decreases in ankle and subtalar motion.

Medial synovial shelf plica syndrome is caused by ac quired thickening and inflammation of a commonly present residual embryonic synovial fold. Treatment with a local injection into the plica and surrounding synovium of a steroid and a long-acting local anesthetic was tested in a series of 30 patients to see if more involved and expensive treatment could be avoided. Thirty-one knees were studied and treated prospec tively ; rigid criteria for making the diagnosis were main tained. Twenty-two (73%) patients had complete relief of pain and full return to activity; five patients had some amelioration of their symptoms and partial return to activity; and three patients had poor results. Two of the poor results were secondary to errors in diagnosis, and one was secondary to the presence of mature fibrosis confirmed during subsequent arthroscopic re section. As a control, ten patients were injected with long-acting local anesthetic alone. In all ten, symptoms were relieved only for the duration of the anesthetic. Intraplical steroid injection appears to be a reasonable, prudent, initial step in the treatment of medial synovial shelf plica syndrome. For competitive athletes, it pro vides very short morbidity and the ability to return to full practice and participation in a very short period of time.

Sixty healthy, athletic children were treated on a Cybex II Dynamometer to obtain values for the relative strengths of the major muscle groups of the lower extremity. Prepubescent and postpubescent boys and girls were tested. Of the anthropometric parameters measured, lean body weight correlated best with max imal torque force development. In prepubescent chil dren, the mean maximal quadriceps torque force, meas ured in foot-pounds at 60 deg/sec, is equal to 70% of the lean body weight. In postpubescent subjects, the mean peak quadriceps torque equalled 80% of the lean body weight in girls and 90% of the lean body weight in boys. Correlations can be established between the maximal torque force generated by the quadriceps and the strength of the hamstrings, ankle dorsiflexors, and plantar flexors. The values obtained are useful in plan ning training and rehabilitation programs and in deter mining when an injured young athlete can safely return to his or her sport.

Strain in the human knee medial collateral ligament (MCL) was measured in cadavers with a Hall effect strain transducer during normal passive knee flexion, as well as knee flexion accompanied by applied external tibial rotation and valgus torques. In an attempt to determine the contribution of the posterior oblique lig ament (POL) to the strain behavior of the MCL, the POL was systematically separated from the MCL and changes in strain in the MCL were observed. These changes in strain were mild and variable, except in the one knee which was later found to be lacking an anterior cruciate ligament. In that particular knee, strain in the MCL increased up to 9.97% under the influence of a valgus torque once the POL fibers had been separated from the MCL. Anatomical dissection and transillumi nation techniques of the MCL/POL complex demon strated definite ligament fibers connecting the MCL to the POL.

The results demonstrate an intimate anatomical re lationship between the POL and MCL. However, the POL and MCL appear to work independently from each other according to our test method.

A group of 295 Israeli infantry recruits was evaluated in a prospective study of stress fractures which began in basic training. On the basis of scintigraphy, 91 of the recruits (31 %) were found to have sustained stress fractures during basic training.

Sixty-six of the 91 recruits with stress fractures (72%) were followed for a minimum of 1 year after basic training to determine the natural history of a soldier who sustains a stress fracture and resumes training after a period of rest. Five clinical patterns were ob served : (1) uneventful recovery (47%); (2) protracted recovery (13.6%); (3) symptoms consistent with recur rent stress fractures in new sites (19.6%); (4) intermit tent nonstress fracture bone pain (16.7%); and (5) chronic stress fractures (3%). The incidence of recur rent stress fractures was 10.6%. A control group of 60 recruits who sustained no stress fractures in basic training had a 1.7% incidence of stress fractures after basic training. Recruits who sustained stress fractures in basic training continued to be a higher risk for stress fractures during subsequent training.

Instrumented anterior/posterior laxity measurements were performed on 138 patients evaluated within 2 weeks of injury with their first traumatic knee hemar throsis. All patients were tested with the MEDmetric Arthrometer model KT-1000 in a knee injury clinic. Seventy-five of the patients had knee arthroscopy. Thirty-three had arthrometer laxity tests under anes thesia. Eighty-seven percent of patients arthroscoped had anterior cruciate ligament (ACL) tears and 41 % had meniscus tears.

One hundred twenty normal subjects were tested to establish normal anterior laxity values. Three tests were used to evaluate anterior laxity: anterior displacement between a 15 and 20 pound force (compliance index), anterior displacement with a 20 pound force, and an terior displacement with a high manually applied force. Displacement measurements in normal subjects re vealed a wide range of normal laxity with a small right knee-left knee difference. For example, the 20 pound anterior displacement range was 3 to 13.5 mm with a right knee-left knee difference (mean ± SD, 0.8 ± 0.7 mm). Eighty-eight percent of the normals had a right- left difference of less than 2 mm.

In the 53 patients arthroscoped who had complete ACL tears, the anterior laxity measurements performed in the clinic were suggestive or diagnostic of pathologic anterior laxity in 50 patients.

In 16 adult dogs the anterior cruciate ligament (ACL) was transected and then reconstructed using freeze dried fascia lata allografts. Eight of the dogs had the intraarticular graft passed through drill holes in the tibia and femur, while in the other eight dogs the graft was passed through a drill hole in the tibia and routed "over- the-top" of the lateral femoral condyle. In all dogs the grafts were then passed deep to the lateral collateral ligament and secondarily secured to the tibia as an extraarticular reconstruction. Specimens from each group underwent histologic study and biomechanical testing on a mechanical testing system at 3, 6, 12, and 24 week intervals.

All grafts were found to be intact at sacrifice with no overt evidence of biologic incompatibility. The knees displayed only mild instability to clinical testing without evidence of arthrosis. Histologically, the grafts ap peared to function as a collagenous scaffolding for revascularization and fibrovascular creeping substitu tion. The mean maximum load at failure in the 24 week specimens reached 536.44 N, compared to values of 801.85 N in contralateral knees with an intact ACL.

Twelve freshly killed mature male rabbits were used to study the effects of continuous passive motion (CPM) on regional and overall nonvascular nutritional path ways of the anterior cruciate ligament (ACL). One hundred fifty microcuries of ³⁵sulphate was injected intraarticularly into each knee joint. The right knee underwent CPM for 1 hour, while the left knee remained immobilized. Both knee joints were then isolated and immediately frozen. The ACLs were removed while still mostly frozen, and sectioned into anterior, middle, and posterior thirds for the six rabbits in Group 1, and proximal, middle, and distal thirds for the six rabbits in Group 2. In addition, quadriceps tendon samples were harvested from each limb of three rabbits. After appro priate processing, all samples were counted in a scin tillation counter, and counts per minute per milligram of tissue were calculated. There was significantly higher uptake in rest extremity ACLs compared to CPM ex tremity ACLs (P = 0.0001 ). No significant difference was demonstrated in regional uptake comparing re spective thirds of the ACL in either Group 1 or Group 2. Quadriceps tendon uptake trended higher in the limbs exposed to CPM compared to those maintained at rest (P = 0.14). The ACL uses diffusion as a primary nutrient pathway. CPM does not increase nutrient up take by the ACL in this avascular model, but CPM may facilitate transport of metabolites out of the joint. No regional differences in uptake within the ACL occurred in either group.

A case of isolated avulsion of the popliteus tendon in a 20-year-old male athlete is reported. The avulsion was caused by forward gliding of the femur on the fixed tibia which produced a chondral fracture and hemar throsis.

Three skiers presented for treatment of significant thumb injuries sustained while skiing. Each patient was using a strapless ski pole handle with a flared thumb support. These skiers felt their interphalangeal (IP) joint flexion was blocked by the flare of their ski pole handle, causing their protruding thumb tip to be the point of initial impact, thus leading to their injury.

Prior to use of any ski pole handle, full flexion of the gloved thumb IP joint should be verified.