Bertram Zarins

Recurrent transient subluxation of the shoulder.

We studied thirty-three normal pa tients, eighteen women and fifteen men, for normal motion and the amount of elbow motion required for fifteen activities of daily living. The amounts of elbow fiexion and forearm rotation (pronation and supina tion) were measured simultaneously by means of an electrogoniometer. Activities of dressing and hygiene require elbow positioning from about 140 degrees of fiexion needed to reach the occiput to 15 degrees of flex ion required to tie a shoe. Most of these activities are performed with the forearm in zero to SO degrees of supination. Other activities of daily living (such as eat ing, using a telephone, or opening a door) are accom plished with arcs of motion of varying magnitudes. Most of the activities of daily living that were studied in this project can be accomplished with 100 degrees of elbow flexion (from 30 to 130 degrees) and 100 degrees of forearm rotation (50 degrees of prona tion and 50 degrees of supination). CLINICAL RELEVANCE: These data, not previously recorded, may be used to provide an objective basis for the determination of disability impairment, to deter mine the optimum position for elbow splinting or ar throdesis, and to assist in the design of elbow pros theses. The motion needed to perform essential daily activities is obtainable with a successful total elbow ar

Recurrent anterior dislocation of the shoulder after surgical repair. Apparent causes of failure and treatment.

We analyzed the cases of thirty-nine patients who were treated for recurrent anterior dislocation of the shoulder after unsuccessful surgical repair for the same condition in order to identify factors responsible for failure of the earlier operations and to determine the results of treatment of the post-surgical recurrence. The prior operations included nineteen Bankart, seven Putti-Platt, five Magnuson, three duToit, two Bristow, and three Nicola procedures. Thirty-two shoulders were treated by reoperation. At reoperation the most common pathological lesion associated with recurrence of the dislocation after the prior repair was a Bankart lesion (avulsion of the capsule and labrum from the anterior glenoid rim). This was present in 84 per cent of the thirty-two shoulders that were treated by reoperation. Excessive laxity of the capsule was found in 83 per cent of the twenty-nine shoulders in which laxity was assessed, and was considered to be the primary cause of instability in four shoulders. A Hill-Sachs lesion of the humeral head was found in 76 per cent of the twenty-nine shoulders that were evaluated for this lesion and was large in three of the shoulders. Other factors that were associated with recurrent instability were scarring of the subscapularis muscle, generalized ligament laxity, technical errors at surgery, and severe reinjury. The success rate of reoperation after previous failure was very encouraging. Of the twenty-four shoulders that were reoperated on and were followed for two years or longer, ten were graded excellent; twelve, good; and two, poor. One (4 per cent) of the twenty-four shoulders that were reoperated on continued to dislocate and another shoulder continued to subluxate, making the incidence of recurrent instability after reoperation 8 per cent. Seven of the thirty-nine shoulders did not have a reoperation but were treated with specific resistive exercises. The results in these were one excellent, four good, one fair, and one poor. Eight patients were lost to follow-up.

Chronic unreduced dislocations of the shoulder.

We evaluated the results of treatment in twenty-three patients with twenty-four shoulder dislocations that had gone unreduced for at least three weeks. Fourteen dislocations were posterior, eight were anterior, and one each was superior and inferior. Seventy-nine per cent of the posterior dislocations had not been recognized by the initial treating physician. Fourteen shoulders (58 per cent) were operated on. Of seven that were treated by open reduction with preservation of the humeral head, the results in two were graded as excellent; in three, as good; and in two, as fair. A Neer total shoulder-replacement prosthesis was used in one patient with an excellent result, and a Neer humeral-head prosthesis was used in two patients with a good and a fair result. In four patients, the humeral head was removed and a Jones procedure was performed, with one good and three fair results. There were no poor results after surgical treatment and it was not necessary to arthrodese any shoulder. We did not find it necessary to transfix the shoulder joint by screws or pins, or to use plaster spica casts to maintain stability of the shoulder following open reduction. Supporting the arm at the side in a position posterior to the coronal plane for a posterior dislocation, and anterior to the coronal plane for an anterior dislocation, proved to be comfortable and effective. There were no postoperative dislocations using this simple method. These results show that the over-all prognosis for surgical treatment of the chronic unreduced dislocation shoulder is more favorable than has previously been reported. A rating system based on 100 units was used to evaluate our final results, and is recommended as a standard system for future comparative studies.

Combined anterior cruciate-ligament reconstruction using semitendinosus tendon and iliotibial tract.

We are reporting the results of a reconstructive procedure designed to decrease anterior tibial subluxation due to disruption of the anterior cruciate ligament. The operation combines both intra-articular and extra-articular methods. The semitendinosus tendon and the iliotibial tract are both routed from opposite directions over the top of the lateral femoral condyle and through the same oblique drill-hole in the proximal part of the tibia: the semitendinosus tendon is passed up through the tibial drill-hole, across the knee joint, over the top of the lateral femoral condyle, and deep to the fibular collateral ligament, and the iliotibial tract is passed deep to the fibular collateral ligament, over the top of the lateral femoral condyle, across the knee joint, and down through the drill-hole. Both grafts are simultaneously pulled tight while the semitendinosus tendon is sutured to the iliotibial tract laterally and the iliotibial tract is sutured to the semitendinosus tendon medially below the drill-hole. The posteromedial and lateral parts of the capsule are advanced to tighten the secondary restraints. One hundred of the first 106 consecutive patients with chronic instability who had this procedure were evaluated using subjective and objective criteria at three to seven and one-half years after surgery. The positive anterior-drawer sign tested at 25 degrees of flexion was eliminated or reduced to 1+ in eighty knees, and the positive pivot shift was reduced to zero or 1+ in ninety-one knees. The objective assessment of isokinetic muscle performance and passive tibial rotation showed significant improvements in strength and normalization of tibial rotation.

Strain measurement in lateral ankle ligaments

We measured strain in the lateral ligaments of 10 human cadaver ankles while moving the ankle joint and apply ing stress in a variety of ways. We studied the anterior talofibular, calcaneofibular, posterior talofibular, ante rior tibiofibular, and posterior tibiofibular ligaments. Strain measurements in the ligaments were recorded continuously while the ankle was moved from dorsiflex ion into plantar flexion. We then repeated measure ments while applying inversion, eversion, internal rota tion, and external rotation forces. Strain in the anterior talofibular ligament increased when the ankle was moved into greater degrees of plantar flexion, internal rotation, and inversion. Strain in the calcaneofibular ligament increased as the talus was dorsiflexed and inverted. These findings support the concept that the anterior talofibular and calcaneofibular ligaments function together at all positions of ankle flexion to provide lateral ankle stability. We measured maximum strain in the posterior talofibular ligament when the ankle was dorsiflexed and externally rotated. The strain in the anterior and posterior tibiofibular liga ments increased when the ankle was dorsiflexed. Ex ternal rotation increased strain in the anterior tibiofibular ligament and decreased strain in the posterior tibiofib ular ligament. Based upon strain measurements in the lateral ankle ligaments in various ankle joint positions, we believe the anterior talofibular ligament is most likely to tear if the ankle is inverted in plantar flexion and internally rotated. Theoretically, the calcaneofibular ligament tears primarily in inversion if the ankle is dorsiflexed; the anterior tibiofibular ligament tears in dorsiflexion, especially if combined with external rotation; and the posterior tibiofibular ligament tears with extreme dor siflexion.

Injuries in women’s professional soccer

Objective: The injury data from the first two seasons of the Women’s United Soccer Association (WUSA) were analysed to determine the injury incidence, anatomic location of injuries, and relation of player position. Methods: Injury data on 202 players from eight teams during the first two seasons of the WUSA were prospectively collected and analysed. Results: A total of 173 injuries occurred in 110 players with an overall injury incidence rate of 1.93 injuries per 1000 player hours. The incidence of injury during practice and games was 1.17 and 12.63 per 1000 player hours, respectively. Of the injuries 82% were acute and 16% were chronic. Most of the injuries (60%) were located in the lower extremities. Strains (30.7%), sprains (19.1%), contusions (16.2%), and fractures (11.6%) were the most common diagnoses and the knee (31.8%) and head (10.9%) were the most common sites of injury. Anterior cruciate ligament (ACL) injuries accounted for 4.6% of all injuries and the incidence of ACL tears was 0.09 per 1000 player hours (practice 0.04, game 0.90). Midfielders suffered the most injuries (p<0.007). Conclusion: We conclude that the injury incidence in the WUSA is lower than the 6.2 injuries per 1000 player hours found in the corresponding male professional league (Major League Soccer); however, knee injuries predominate even in these elite female athletes.

Reconstruction of the lateral ankle ligaments. A biomechanical analysis.

The purpose of this study was to perform a biome chanical analysis of several commonly performed op erative procedures used to stabilize the lateral ankle. We performed the Evans, Watson-Jones, and Chris man-Snook procedures on 15 cadaveric ankles and tested the ankles for stability, motion, and isometry of graft placement. The Evans procedure allowed in creased anterior displacement, internal rotation, and tilt of the talus when compared to ankles with intact liga ments. Subtalar joint motion was restricted by the Evans procedure. The Watson-Jones procedure con trolled internal rotation and anterior displacement of the talus, but was less effective in controlling talar tilt and also restricted subtalar joint motion. The Chrisman- Snook procedure allowed increased internal rotation and anterior displacement of the talus when compared to ankles with intact ligaments. The procedure was effective in limiting talar tilt, but restricted subtalar joint motion. Based on the biomechanical data obtained, we de vised a lateral ankle reconstruction with bone tunnels that reproduce the anatomic orientation of both the anterior talofibular and calcaneofibular ligaments. This ankle ligament reconstruction resists anterior displace ment, internal rotation, and talar tilt without restricting subtalar joint motion. Clinical relevance: We found considerable mechanical differences among the more commonly performed lat eral ankle reconstructions. It is possible to locate bone tunnels and graft placement so that a more anatomic configuration is achieved.

Measurement of anterior-posterior displacement of the knee. A comparison of the results with instrumented devices and with clinical examination.

Thirteen subjects who had normal knees and fifteen patients who had a chronic rupture of the anterior cruciate ligament were tested in order to compare the measurements of tibiofemoral displacement as recorded by four commercial devices: the Acufex knee-signature system, the Genucom knee-analysis system, the Medmetric KT-1000 arthrometer, and the Stryker knee-laxity tester. Anterior and posterior displacement were measured at forces of eighty-nine newtons (twenty pounds) and 133 newtons (thirty pounds). We found significant differences in reproducibility of measurement among the devices. The Acufex, Medmetric, and Stryker devices had more reproducible measurements, and they could be used to identify 80 to 90 per cent of the normal subjects and anterior cruciate-deficient patients. The Genucom device had poorer reproducibility of measurement, and it tended to register greater differences in displacement between the right and left knees of normal subjects.

Hamstring muscle strains in professional football players: a 10-year review.

Background: Investigations into hamstring strain injuries at the elite level exist in sports such as Australian Rules football, rugby, and soccer, but no large-scale study exists on the incidence and circumstances surrounding these injuries in the National Football League (NFL). Hypothesis: Injury rates will vary between different player positions, times in the season, and across different playing situations. Study Design: Descriptive epidemiology study. Methods: Between 1989 and 1998, injury data were prospectively collected by athletic trainers for every NFL team and recorded in the NFL’s Injury Surveillance System. Data collected included team, date of injury, activity the player was engaged in at the time of injury, injury severity, position played, mechanism of injury, and history of previous injury. Injury rates were reported in injuries per athlete-exposure (A-E). An athlete-exposure was defined as 1 athlete participating in either 1 practice or 1 game. Results: Over the 10-year study period 1716 hamstring strains were reported for an injury rate (IR) of 0.77 per 1000 A-E. More than half (51.3%) of hamstring strains occurred during the 7-week preseason. The preseason practice IR was significantly elevated compared with the regular-season practice IR (0.82/1000 A-E and 0.18/1000 A-E, respectively). The most commonly injured positions were the defensive secondary, accounting for 23.1% of the injuries; the wide receivers, accounting for 20.8%; and special teams, constituting 13.0% of the injuries in the study. Conclusion: Hamstring strains are a considerable cause of disability in football, with the majority of injuries occurring during the short preseason. In particular, the speed position players, such as the wide receivers and defensive secondary, as well as players on the special teams units, are at elevated risk for injury. These positions and situations with a higher risk of injury provide foci for preventative interventions.

Lipoma arborescens of the knee

Lipoma arborescens is a rare intra-articular lesion, characterised by diffuse replacement of the subsynovial tissue by mature fat cells, producing prominent villous transformation of the synovium. The aetiology of this benign condition is unknown. We describe six cases involving the knee, discussing the symptoms, diagnosis and treatment.