John A. Feagin

Mechanisms of anterior cruciate ligament injury.

This study examined the mechanisms of anterior cruciate ligament (ACL) injury. In the first part of the study, using a comprehensive, standardized questionnaire, 89 athletes (100 knees) were interviewed about the events surrounding their ACL injury. A noncontact mechanism was reported in 71 (72%) knees and a contact injury in 28 (28%) knees; one patient was unsure if there was any contact. Most of the injuries were sustained at footstrike with the knee close to full extension. Noncontact mechanisms were classified as sudden deceleration prior to a change of direction or landing motion, while contact injuries occurred as a result of valgus collapse of the knee. Hamstring flexibility parameters revealed a statistically higher level of laxity in the injured athletes compared with a matched group of 28 controls. In the second part of the study, videotapes of 27 separate ACL disruptions were reviewed and confirmed that most noncontact injuries occur with the knee close to extension during a sharp deceleration or landing maneuver. Because the knee is in a position to allow the extensor mechanism to strain the ACL and maximum, eccentric muscle force conditions usually apply, the quadriceps may play an important role in ACL disruption. Passive protection of the ACL by the hamstring muscles may be reduced in patients with above-average flexibility.

Isolated tear of the anterior cruciate ligament: 5-year follow-up study.

During the period 1967 to 1971, 64 cadets at the United States Military Academy, West Point, New York, had surgical repair for isolated tear of the anterior cruciate ligament. In a 5-year follow-up study to determine the functional impairment, present disability, and reinjury to the knee, 32 of the 64 patients were located and evaluated by radiographic examination and either by interview or by questionnaire. Twenty-two were commissioned to full duty. 23 had attended ranger or airborne school, and 16 had been in combat. Impairment of ordinary activities was noted by 12 and impairment of athletic endeavors by 24; pain by 71%; swelling by 66%; stiffness by 71%; and instability by 94%. Seventeen of the 32 had had a significant reinjury after the repair of the anterior cruciate ligament. Clinically, we can diagnose the isolated tear of the anterior cruciate ligament by four essential ingredients--a pop at time of injury, inability to continue participation, gross swelling of knee, and maximal swelling within 12 hr. The mechanism of injury is usually deceleration and change of direction, not contact with another player. The follow-up study on this small series indicates that the patients have progressive deterioration of the knee.

Osseous injury associated with acute tears of the anterior cruciate ligament

Multiplanar spin-echo magnetic resonance imaging was performed on 54 patients with acute complete anterior cruciate ligament tears. Imaging was done within 45 days of index anterior cruciate ligament injury. Spin- echo T1- and T2-weighted images were used to deter mine the lesion morphology and location. Only the T2- weighted sagittal images were used for the incidence assessment; T2-weighted spin-echo imaging reflects free water shifts and best indicates the acute edema and inflammatory changes from injury. Eighty-three percent (45 of 54) of the knees had an osseous contusion directly over the lateral femoral con dyle terminal sulcus. The lesion was highly variable in size and imaging intensity; however, the most intense signal was always contiguous with the subchondral plate. Posterolateral joint injury was seen in 96% (43 of 45) of the knees that had a terminal sulcus osseous lesion determined by magnetic resonance imaging. This posterolateral lesion involves a spectrum of injury, in cluding both soft tissue (popliteus-arcuate capsuloliga mentous complex) and hard tissue (posterolateral tibial plateau) injuries. The consistent location of the osseous and soft tissue injuries underscores a necessary similar mechanism of injury associated with these acute anterior cruciate ligament tears. Based on these characteristic findings, several proposed mechanisms of injury are discussed.

Experimental studies of acute anterior cruciate ligament injury and repair

Ten dogs and six rhesus monkeys underwent transection and repair of the anterior cruciate ligament. One-half of the pro cedures involved the femoral end, the other half involved the tibial end of the ligament. Seven of the 10 canine and all of the primate ligaments, that had been transected and repaired, did heal. Functional and clinical instability was demonstrable in all repaired knees. The monkeys developed fewer degenerative changes with more grossly normal appearing ligaments after the repairs than did the dogs. Failure testing on an Instron materials testing machine revealed maximum strength of the repaired ligaments to be 10.4% for the repairs at the femoral end and 2.0% for repairs at the tibial ends in dogs when compared with the contralateral control knees. In monkeys the femoral repairs were 46.8% and the tibial repairs were 62.6% of the control knees. Inadequate immobilization and early stress were believed to be principal causes of the poorer results in dogs. The observations in monkeys support the suggestion that injured anterior cruciate ligaments that can be repaired, should be repaired.

Quadriceps Contusions in Young Athletes: Relation Of Severity Of Injury To Treatment And Prognosis

Army cadets who had sports injuries to their quadriceps femoris during one academic year were grouped according to the severity of the contusion-mild, moderate, or severe. The extent to which knee flexion was limited ( 120 degrees) corresponded to the severity of injury as did

Patellofemoral Instability: Evaluation and Management.

&NA; Patellofemoral disorders are a common cause of knee pain and disability. A thorough history and a careful physical examination are essential to accurate diagnosis, and imaging modalities play an important role. Magnetic resonance imaging can provide information on malalignment and soft‐tissue injuries. Although there is a continuum of diagnoses, most patellofemoral disorders can be divided into three distinct categories: soft‐tissue abnormalities, patellar instability due to subluxation and dislocation, and patellofemoral arthritis. Many patellofemoral disorders respond to nonoperative therapy. When surgical intervention is necessary, patellar tilt can be successfully treated by a lateral release. Lateral patellar subluxation associated with malalignment can be corrected by a distal realignment procedure such as the anteromedial tibial tubercle transfer. Repair of the medial patellofemoral ligament in cases of patellar dislocation has considerably lowered the incidence of recurrent instability. Although no ideal treatment exists for patellofemoral arthritis, mechanical symptoms may be alleviated by arthroscopic debridement of delamination lesions. Articular cartilagewear disorders may be stabilized by addressing the primary causative disorder.

Acute anterior cruciate ligament injury and augmented repair Experimental studies

Eleven dogs underwent transection of the anterior cruciate ligament at the femoral origin of the stifle (knee) joint. The anterior cruciate ligaments were repaired in a conventional manner and augmented by transferring the medial one-third of the patellar tendon and inserting it into the lateral femoral condyle. The repairs were evaluated either 4 or 8 months postoperatively. All repaired and augmented anterior cruciate ligaments in this series healed satisfactorily to provide clinical and functional stability to the knee joints. Instron testing of the repaired and augmented anterior cruciate ligaments showed maximum strength at 4 months of 46.2 ± 10.9 kgf and at 8 months of 64.3 ± 14.3 kgf as compared to the control of 122.7 ± 11.6 kgf. Histologic evaluation showed that by 8 months the repaired and augmented anterior cruciate ligaments had healed by bony ingrowth. Thus, interstitial failure occurred during Instron testing. The transferred patellar tendon provided ad ditional blood supply, splinted the anterior cruciate ligament to allow healing, and increased the strength of the repaired com plex.

Implications of the pivot shift in the ACL-deficient knee

The Losee repair controls rotational subluxation of the lateral femoral condyle, or pivot shift, but does not reliably eliminate Lachman laxity. Despite this surgical limitation, many patients who were operated on continued to do high-demand activities at the last followup. We hypothesized that Lachman findings alone did not predict poor surgical outcome or progression to osteoarthritis. We report on 87 patients evaluated at an average of 9 years (range, 5-21 years) postoperatively. Prospectively collected examinations and radiographic, subjective, and objective outcome measures were recorded and statistically evaluated. The presence of a postoperative pivot shift or residual varus laxity correlated with poor patient subjective evaluations and poor scoring outcomes. Lachman laxity with an absent pivot shift had no correlation with the outcome measures or onset of radiographic progression to osteoarthritis. Meniscectomy, additional knee surgery, increased valgus or varus laxity, and time from injury until the final radiograph positively correlated with the onset of osteoarthritis. Elimination of the pivot shift was necessary to achieve successful relief of symptoms and functional outcome. In the absence of a pivot shift, Lachman laxity was not solely predictive of poor outcomes. Level of Evidence: Prognostic study, Level II-1 (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

Ski injury statistics, 1982 to 1993, Jackson hole ski resort

A retrospective analysis was conducted on injury statistics compiled over 12 seasons, from 1982 to 1993 (2.55 million skier-days), at a Wyoming ski resort. The population at risk was determined by ticket sales per year. A total of 9749 skiing injuries was indexed by anatomic region and se verity according to diagnosis on initial evaluation. Injury rates were then analyzed as a function of time. The injury rate remained constant at 3.7 injuries per 1000 skier-days during the 12 seasons. The rate of lower extremity to up per extremity injury decreased from 4:1 to 2:1 during the study period (P < 0.03). The ankle injury rate also de creased with time (P < 0.04). Ulnar collateral ligament sprains make up 7% of all injuries. Knee sprains in general account for 30% of all injuries. The incidence of anterior cruciate ligament tears increased as a function of time (P < 0.04) and accounted for 16% of all skiing injuries during the study period. The medial collateral ligament sprain was the most common injury, making up 18% of skiing injuries. Forty-seven snowboard injuries from the 1992 to 1993 season are also presented. Our injury statistics mir ror those currently reported in North America, except our data reflect a higher incidence of knee sprains.

Isolated Tears of the Anterior Cruciate Ligament Over 30-Year Follow-up of Patients Treated With Arthrotomy and Primary Repair

Background Over 30 years ago, Feagin and Curl reported on the diagnosis and treatment of “isolated” injuries of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the long-term results of the patients initially diagnosed with tears of the ACL, with special emphasis on those treated with primary repair. Hypothesis Long-term results are unsatisfactory for open evaluation and treatment of ACL injuries with or without primary repair. Study Design Case series; Level of evidence, 4. Methods Follow-up was available on 34 of the original 57 patients (60%) who had ACL tears on evaluation by arthrotomy. The average age at the index procedure was 20 years, and average follow-up was 32 (range, 29-36) years. Twenty-five of the 26 complete ACL tears were treated with primary repair. None of the 8 partial tears was repaired. Evaluations included the subjective and symptom ratings of the International Knee Documentation Committee (IKDC) evaluation form, Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner activity scale, and SANE rating. Results For the IKDC subjective score, 18 of 34 patients rated their knees as normal or nearly normal. The Lysholm scores averaged 70.1 (range, 20-100). The average SANE rating at 5 years was 74.8 (range, 49-110), and the current SANE rating averaged 68.9 (range, 10-100). The overall KOOS rating averaged 68.6 (range, 26.4-100). The Tegner activity score was 3.7. There was little difference between patients with unrepaired partial tears and those who had primary repairs. Conclusion At more than 30-year follow-up, patients have decreased activity levels and an equal mix of acceptable and unacceptable outcomes. We were unable to identify any predictive factors that correlated with the results; however, subsequent meniscal surgery did correlate with poor results. The results at greater than 30 years reinforce the 5-year results that showed unsatisfactory results after the open evaluation and treatment of ACL injuries with or without repair.