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

Mechanisms of anterior cruciate ligament injury.

We evaluated specimens obtained from the biopsy of spontaneously ruptured tendons in 891 patients who were treated between 1968 and 1989. The specimens, which were removed at the time of repair, included 397 Achilles tendons, 302 biceps brachii tendons, forty extensor pollicis longus tendons, eighty-two quadriceps tendons and patellar ligaments, and seventy other tendons. Age and sex-matched control specimens, from 445 tendons taken at the time of death from the cadavera of previously healthy individuals who died accidentally, also were obtained and evaluated. The histopathological analyses of the specimens included light and polarized light microscopy and scanning and transmission electron microscopy. A healthy structure was not seen in any spontaneously ruptured tendon, but two-thirds of the control tendons were structurally healthy (p less than 0.001). There were characteristic histopathological patterns in the spontaneously ruptured tendons. Most (97 per cent) of the pathological changes were degenerative; they included hypoxic degenerative tendinopathy, mucoid degeneration, tendolipomatosis, and calcifying tendinopathy, either alone or in combination. These changes were also found in 34 per cent of the control tendons, but significantly less frequently (p less than 0.001). In the other twenty-six ruptured tendons (3 per cent), the pathological change was an intratendinous foreign body, rheumatoid tendinitis, a xanthoma, a tumor, or a tumor-like lesion such as an intratendinous ganglion. The findings clearly indicate that, at least in an urban population, degenerative changes are common in the tendons of people who are older than thirty-five years and that these changes are associated with spontaneous rupture.

Histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients

OBJECTIVE: To describe the functional anatomy of the ankle complex as it relates to lateral ankle instability and to describe the pathomechanics and pathophysiology of acute lateral ankle sprains and chronic ankle instability. DATA SOURCES: I searched MEDLINE (1985-2001) and CINAHL (1982-2001) using the key words ankle sprain and ankle instability. DATA SYNTHESIS: Lateral ankle sprains are among the most common injuries incurred during sports participation. The ankle functions as a complex with contributions from the talocrural, subtalar, and inferior tibiofibular joints. Each of these joints must be considered in the pathomechanics and pathophysiology of lateral ankle sprains and chronic ankle instability. Lateral ankle sprains typically occur when the rearfoot undergoes excessive supination on an externally rotated lower leg. Recurrent ankle sprain is extremely common; in fact, the most common predisposition to suffering a sprain is the history of having suffered a previous ankle sprain. Chronic ankle instability may be due to mechanical instability, functional instability, or most likely, a combination of these 2 phenomena. Mechanical instability may be due to specific insufficiencies such as pathologic laxity, arthrokinematic changes, synovial irritation, or degenerative changes. Functional instability is caused by insufficiencies in proprioception and neuromuscular control. CONCLUSIONS/RECOMMENDATIONS: Lateral ankle sprains are often inadequately treated, resulting in frequent recurrence of ankle sprains. Appreciation of the complex anatomy and mechanics of the ankle joint and the pathomechanics and pathophysiology related to acute and chronic ankle instability is integral to the process of effectively evaluating and treating ankle injuries.

Functional Anatomy, Pathomechanics, and Pathophysiology of Lateral Ankle Instability.

ObjectiveTo describe the mechanisms for anterior cruciate ligament injuries in female team handball.Study DesignDescriptive video analysis.MethodsTwenty videotapes of anterior cruciate ligament injuries from Norwegian or international competition were collected from 12 seasons (1988-2000). Three medical doctors and 3 national team coaches systematically analyzed these videos to describe the injury mechanisms and playing situations. In addition, 32 anterior cruciate ligament-injured players in the 3 upper divisions in Norwegian team handball were interviewed during the 1998-1999 season to compare the injury characteristics between player recall and the video analysis.ResultsTwo main injury mechanisms for anterior cruciate ligament injuries in team handball were identified. The most common (12 of 20 injuries), a plant-and-cut movement, occurred in every case with a forceful valgus and external or internal rotation with the knee close to full extension. The other main injury mechanism (4 of 20 injuries), a 1...

Injury Mechanisms for Anterior Cruciate Ligament Injuries in Team Handball A Systematic Video Analysis

This article systematically reviews epidemiological studies on sports injury from 1977 to 2005 in which ankle injury was included. A total of 227 studies reporting injury pattern in 70 sports from 38 countries were included. A total of 201 600 patients were included, with 32 509 ankle injuries. Ankle injury information was available from 14 098 patients, with 11 847 ankle sprains. Results show that the ankle was the most common injured body site in 24 of 70 included sports, especially in aeroball, wall climbing, indoor volleyball, mountaineering, netball and field events in track and field. Ankle sprain was the major ankle injury in 33 of 43 sports, especially in Australian football, field hockey, handball, orienteering, scooter and squash. In sports injuries throughout the countries studied, the ankle was the second most common injured body site after the knee, and ankle sprain was the most common type of ankle injury. The incidence of ankle injury and ankle sprain was high in court games and team sports, such as rugby, soccer, volleyball, handball and basketball. This systematic review provides a summary of the epidemiology of ankle injury in sports.

/pdf/a-systematic-review-on-ankle-injury-and-ankle-sprain-in-4g9zbsl6fu.pdf

A systematic review on ankle injury and ankle sprain in sports.

Treatment for acute tears of the lateral ligaments of the ankle. Operation, cast, or early controlled mobilization.

The objectives of this study were to measure strain in the ACL during simulated: hamstring activity alone, quadriceps activity alone, and simultaneous quadriceps and hamstring activity. Seven knee specimens removed from cadavers were studied. Heavy sutures applied to load cells were attached to the hamstring and quadriceps tendons. Loads were then applied manually (hamstrings) and/or with an Instron testing machine (quadriceps) to simulate isometric contractions of the various muscle groups. Strain was measured using a Hall effect transducer. Acting alone, the isometric hamstring activity decreased ACL strain relative to the passive normal strain at all positions tested. Thus, hamstring exercises are not detrimental to ACL repairs or reconstruction and can be included early in the rehabilitation program after ACL surgery. Acting alone, at flexion angles of 0 degree to 45 degrees, the quadriceps significantly increased the strain within the ACL relative to the passive normal strain. Strain in the ACL during simultaneous hamstring and quadriceps activity was significantly higher than that during passive normal motion from full extension to 30 degrees of flexion. The hamstrings are not capable of masking the potentially harmful effects of simultaneous quadriceps contraction on freshly repaired or reconstructed ACLs unless the knee flexion angle exceeds 30 degrees.

Strain within the anterior cruciate ligament during hamstring and quadriceps activity

Before studying the biomechanical effects of rehabilitation exercises on the reconstructed knee, it is important to understand their effects on the normal anterior cruciate ligament. The objective of this investigation was to measure the strain behavior of this ligament during rehabilitation activities in vivo. Participants were patient volunteers with normal anterior cruciate ligaments instrumented with the Hall effect transducer. At 10 degrees and 20 degrees of flexion, ligament strain values for active extension of the knee with a weight of 45 N applied to a subject's lower leg were significantly greater than active motion without the weight. Isometric quadriceps muscle contraction at 15 degrees and 30 degrees also produced a significant increase in ligament strain, while at 60 degrees and 90 degrees of knee flexion there was no change in ligament strain relative to relaxed muscle condition. Simultaneous quadriceps and hamstrings muscles contraction at 15 degrees produced a significant increase in ligament strain compared with the relaxed state but did not strain the ligament at 30 degrees, 60 degrees, and 90 degrees of flexion. Isometric contraction of hamstrings muscles did not produce change in ligament strain at any flexion angle. Exercises that produce low or unstrained ligament values, and would not endanger a properly implanted graft, are either dominated by the hamstrings muscle (isometric hamstring), involve quadriceps muscle activity with the knee flexed at 60 degrees or greater (isometric quadriceps, simultaneous quadriceps and hamstrings contraction), or involve active knee motion between 35 degrees and 90 degrees of flexion.

Anterior Cruciate Ligament Strain Behavior During Rehabilitation Exercises In Vivo

https://onlinelibrary.wiley.com/doi/pdf/10.1016/S0736-0266%2800%2990004-4

Ankle ligament injury risk factors: a prospective study of college athletes

The treatment of injuries of the anterior cruciate ligament. R Johnson;B Beynnon;C Nichols;P Renstrom; The Journal of Bone & Joint Surgery

Per A. Renström

Papers

Treatment for acute tears of the lateral ligaments of the ankle. Operation, cast, or early controlled mobilization.

Strain within the anterior cruciate ligament during hamstring and quadriceps activity

Anterior Cruciate Ligament Strain Behavior During Rehabilitation Exercises In Vivo

Ankle ligament injury risk factors: a prospective study of college athletes

The treatment of injuries of the anterior cruciate ligament.