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PubMed2002

Anterior cruciate ligament reconstruction using hamstring tendon grafts.

The annual incidence of more than 100,000 anterior cruciate ligament tears has increased with the rise of participation in sports in the general population, especially in females and older participants. Anterior cruciate ligament reconstruction is the standard of care in the young and/or athletically active individuals, based on prospective randomized studies. Replacement tissues to reconstruct the anterior cruciate ligament can be categorized as autograft, allograft, xenograft, and artificial replacements. Historically, xenograft and artificial replacements for the anterior cruciate ligament have failed dismally. As a result, autograft and allograft tissues commonly are used to reconstruct the anterior cruciate ligament. Autograft tissue currently is the most common source for grafts used worldwide. The two most common autograft tissues are the bone-patellar tendon-bone and hamstrings tendons. Controversy exists regarding the advantages and disadvantages of using each of these two tissues. The purpose of the current study was to review the basic science and clinical data regarding the use of the hamstring tendons in anterior cruciate ligament reconstruction.

Adult↗
PubMed2003

Messenger ribonucleic acid levels in disrupted human anterior cruciate ligaments.

Thirty patients had anterior cruciate ligament reconstruction for ongoing instability. Two groups were defined according to gross morphologic features identified during reconstruction: anterior cruciate ligament disruptions with scars attached to a structure in the joint and disruptions without reattachments. Reverse transcription polymerase chain reaction for a subset of extracellular matrix molecules, proteinases, and proteinase inhibitors was done on samples of scarred anterior cruciate ligament tissue removed during reconstructive surgery. Results of the nonattached scar group showed significantly increased mRNA levels for Type I collagen, and an increased Type I to Type III collagen ratio compared with that for the attached scar group. In the first year after injury, decorin mRNA levels in the nonattached scar group also were significantly higher than in the attached scar group. Biglycan mRNA levels in the nonattached scar group correlated closely with Type I collagen mRNA levels. These results suggest differences in cellular expression in torn anterior cruciate ligaments that attach to structures in the joint versus those which do not. Although the molecular mechanisms responsible for these differences have not been delineated, different molecular signals may influence the gross morphologic features of anterior cruciate ligament disruptions or alternatively, differing gross morphologic features may be subject to different mechanical loads leading to altered molecular expression. However, the finding of endogenous cellular activity in injured anterior cruciate ligaments raises the possibility that this activity may be enhanced to improve outcomes.

Actins↗
PubMed2003

Anterior cruciate ligament injury in children: update of current treatment options.

As our society's interest in competitive athletics has grown, so has the participation of our youth. Unfortunately, along with this increase in participation has come a predictable increase in rate of injury. More specifically, anterior cruciate ligament injury in the skeletally immature individual is being recognized with increasing frequency and currently poses an unsolved clinical problem. Conservative management of midsubstance anterior cruciate ligament tears in the skeletally immature population has been shown to have an unfavorable prognosis related to functional knee instability, subsequent meniscal tears, and the development of early degenerative arthritis. Despite poor outcomes following conservative treatment, many orthopaedic surgeons have been reluctant to perform anterior cruciate ligament reconstructions in skeletally immature patients due to the potential for physeal injury and resultant growth disturbance. Although there is growing evidence in the literature suggesting that anterior cruciate ligament reconstruction in the adolescent population may be safely performed using anatomic, transphyseal techniques, there are insufficient data to provide concrete guidelines in treatment of anterior cruciate ligament injuries in the prepubescent population. Management of these injuries, therefore, must be based on the physiologic and skeletal maturity of the child. Anterior cruciate ligament reconstruction in the skeletally immature individual still poses a clinical problem with the safest and most effective techniques still evolving.

Adolescent↗
PubMedDate not supplied

Intra-articular replacement of bovine cranial cruciate ligaments with an autogenous fascial graft.

Transected cranial cruciate ligaments in nine Holstein heifers were replaced with an autograft harvested from fascia on the medial surface of the gluteobiceps muscle and a connected segment of the lateral patellar ligament. There was minimal lameness at month 1, and all animals were sound by month 2. There was no evidence of degenerative joint disease in any stifles examined at necropsy on days 90, 120, or 365. Augmented healing of the severed cranial cruciate ligaments occurred in several animals. The mean failure strength of the cranial cruciate ligament replacements was 29.7% of the failure strength of the contralateral normal cranial cruciate ligament in four heifers. The technique was successful in eight of 13 bulls and cows with ruptured cranial cruciate ligaments. Animals treated successfully had significantly lower body weights than those with unsuccessful outcomes.

Animals↗
PubMed1997

Registration of cruciate ligament injuries in Norwegian top level team handball. A prospective study covering two seasons.

All cruciate ligament injuries in the three upper divisions for men and women (3392 players) in Norwegian team handball in the 1989-90 and 1990-91 seasons were registered. A questionnaire was mailed to all injured players. Ninety-three cruciate ligament injuries were registered; 87 in the anterior cruciate ligament (ACL), and six in the posterior cruciate ligament (PCL). Among women, 1.8% were injured compared with 1.0% of the men. In the first division, the risk of being injured was considerably higher: 4.5% of the players had a cruciate ligament injury. There were 0.97 cruciate ligament injuries per 100 playing hours in the three divisions taken together. Seventy-five per cent of the injuries occurred during games. Ninety-five per cent involved no contact between players. Activities in which the friction between shoe and floor was significant caused 55% of the injuries. Injuries caused by running into another player contributed to only 5% of the injuries. No significant differences were observed in injury incidence during matches between different types of floors (parquet, Pulastic and other synthetic surfaces.)

Adolescent↗
PubMedDate not supplied

Influence of exogenous growth factors on the expression of plasminogen activators by explants of normal and healing rabbit ligaments.

In this investigation we have demonstrated that specific growth factors are able to modify plasminogen activator (PA) activity in explants from both normal and healing ligaments. Specifically, the addition of insulin-like growth factor 2 (IGF-2; 100 ng/mL) and transforming growth factor beta 1 (TGF-beta 1; 2.5 ng/mL) to explants of unoperated and healing ligaments resulted in a decrease in both PA and PA--PA-binding protein complex in conditioned medium from several tissues, and particularly in medial collateral ligament (MCL) scar tissue. This effect was observed in the explants from 3-, 6-, and 12-week healing scar tissue. In addition, IGF-2 and TGF-beta 1 influenced PA release from MCL tissue derived from the unoperated knee joint of 3-week healing animals. In contrast, basic fibroblast growth factor (b-FGF; 10 ng/mL) and IGF-1 (100 ng/mL) did not cause a detectable alteration of PA and PA--PA-binding protein complex activity in any of the healing or unoperated ligaments analyzed. These results indicate that specific growth factors are able to modify the activity of cells in explants of ligament and healing ligament in a distinct manner.

Animals↗
PubMed1990

Ligaments of the lateral aspect of the ankle and sinus tarsi: an MR imaging study.

The normal anatomy of the lateral ankle and subtalar ligaments seen at magnetic resonance (MR) imaging was studied in four cadaver ankles. Sixteen ankles of 11 healthy volunteers were imaged with four different MR imaging protocols to optimize technique. The anterior talofibular ligament was identified in 100% of the ankles of the volunteers in the axial plane, the calcaneofibular ligament in 81% of the ankles in the coronal plane, the cervical ligament in 69% of the ankles in the coronal plane and in 88% of the ankles in the sagittal plane, and the talocalcaneal ligament in 56% of the ankles in the coronal plane and in 62% of the ankles in the sagittal plane. It is concluded that thin-section (1-3-mm) MR imaging techniques, especially the one in which data are acquired with three-dimensional Fourier transform, are best for visualization of the ligaments. These techniques may play a role in the evaluation of patients with chronic ankle pain and instability.

Adult↗
PubMedDate not supplied

Current trends in anterior cruciate ligament reconstruction. Part II. Operative procedures and clinical correlations.

Surgical management of the anterior cruciate ligament-deficient knee has evolved from primary repair to extracapsular augmentation to anterior cruciate ligament reconstruction using biologic tissue grafts. The technique of anterior cruciate ligament reconstruction has improved over the last few decades with the aid of knowledge gained from basic science and clinical research. The biology and biomechanics of anterior cruciate ligament reconstruction were analyzed in the previously published first part of this article. In this second part, current operative concepts of anterior cruciate ligament reconstruction as well as clinical correlations are discussed. The latest information regarding anterior cruciate ligament reconstruction is presented with a goal of demonstrating the correlation between the application of basic science knowledge and the improvement of clinical outcomes.

Anterior Cruciate Ligament↗
PubMedDate not supplied

Intrinsic and extrinsic risk factors for anterior cruciate ligament injury in Australian footballers.

The aim of this study was to examine the interaction between intrinsic (player-related) and extrinsic (environment-related) variables as risk factors for anterior cruciate ligament injury in Australian football. Between 1992 and 1999, 100,820 player-match exposures were analyzed for risk of anterior cruciate ligament injury using logistic regression analysis. There were 63 surgically proven noncontact anterior cruciate ligament injuries. The strongest risk factors were a player history of anterior cruciate ligament reconstruction either in the previous 12 months (relative risk [RR], 11.33; 95% confidence interval [CI], 4.02 to 31.91) or before the previous 12 months (RR, 4.44; 95% CI, 2.46 to 8.01). Weather conditions that were associated with dry field conditions--high water evaporation in the month before the match (RR, 2.55; 95% CI, 1.44 to 4.52) and low rainfall in the year before the match (RR, 2.87; 95% CI, 1.30 to 6.32)--were also significantly associated with these injuries. The increased risk of injury in the first 12 months after reconstruction was associated with the reconstructed knee, whereas after 12 months there was an even distribution of new injuries to the reconstructed knee and contralateral knee. A history of anterior cruciate ligament reconstruction is a risk factor for further injury. Weather conditions of high evaporation and low rainfall before matches are associated with noncontact anterior cruciate ligament injury.

Adult↗
PubMedDate not supplied

Progressive loss of knee extension after injury. Cyclops syndrome due to a lesion of the anterior cruciate ligament.

Cyclops syndrome has been defined as a loss of knee extension due to impingement of a pedunculated proliferative tissue mass after anterior cruciate ligament reconstruction. We describe four patients who were operated on for progressive loss of knee extension after minor knee injury. During the arthroscopic procedure, the consistent finding was a fibrous pedunculated nodule adhering to the anterolateral aspect of the original anterior cruciate ligament, obstructing extension by impingement in the anterior aspect of the knee. At least part of the anterior cruciate ligament was intact in all cases. These patients were compared with seven patients who developed cyclops syndrome after anterior cruciate ligament reconstruction. Clinical and arthroscopic findings were the same in both groups. An arthroscopic excision of the nodule, performed an average of 12 weeks after knee trauma or after reconstruction, gave very good results. Histologic examination of the excised nodules from both groups showed fibroelastic connective tissue proliferation, thromboangiitis, and areas of necrotic bone and foreign body giant cell granuloma. On the basis of our observations, we conclude that formation of a fibrous pedunculated nodule may occur after an anterior cruciate ligament injury as well as after surgical reconstruction of the anterior cruciate ligament.

Adolescent↗
PubMedDate not supplied

The relationship of the femoral origin of the anterior cruciate ligament and the distal femoral physeal plate in the skeletally immature knee. An anatomic study.

We defined the anatomic relationship of the anterior cruciate ligament femoral origin to the distal femoral physis in the skeletally immature knee with use of 12 fresh-frozen human fetal specimens (ages, 20 to 36 weeks). Each specimen underwent magnetic resonance imaging, was dissected free of soft tissue, sectioned in the sagittal plane, and stained. The spatial relationship of 1) the epiphyseal side of the physeal proliferative zone to the nearest point of bony attachment of the anterior cruciate ligament and 2) the origin of the anterior cruciate ligament to the over-the-top position were measured. The same measurements were made in 13 skeletally immature knees (ages, 5 to 15 years). We found that the femoral origin of the fetal anterior cruciate ligament developed as a confluence of ligament fibers with periosteum at 20 weeks, vascular invasion into the epiphysis at 24 weeks, and establishment of a secure epiphyseal attachment by 36 weeks. In the fetus, the distance from the anterior cruciate ligament femoral origin to the epiphysis was 2.66+/-0.18 mm (range, 2.34 to 2.94). There was no significant change in this distance in adolescent specimens (2.92+/-0.68 mm; range, 2.24 to 3.62). The over-the-top position was at the level of the distal femoral physis.

Adolescent↗
PubMedDate not supplied

Reconstruction of the lateral ankle ligaments with bone-patellar tendon graft in patients with chronic ankle instability: a preliminary report.

BACKGROUND: Unsatisfactory long-term results have been reported after use of a Broström repair for patients with chronic ankle ligament insufficiency. HYPOTHESIS: Repair or reconstruction of both the anterior talofibular and calcaneofibular ligaments is essential for normal kinematics of the ankle-hindfoot. STUDY DESIGN: Case series. METHODS: Thirteen patients with chronic instability of the ankle were found at operation to have injuries of both the anterior talofibular and calcaneofibular ligaments, with a lack of healthy ligament margins suitable for suturing. Reconstruction of the ligaments was performed with bone-patellar tendon graft. The score devised by Good et al. was used to assess the patients' clinical condition before the operation and at final follow-up. RESULTS: Before the operation, six patients had a grade 3 clinical condition and seven had a grade 4 condition. At a mean follow-up of 26.5 months, all patients had a grade 1 condition. The average talar tilt of the patients was improved from 18.4 degrees +/- 5.5 degrees to 4.9 degrees +/- 2.6 degrees, and the average anterior drawer sign was improved from 9.1 +/- 2.6 mm to 5.8 +/- 1.6 mm. CONCLUSION: In cases of combined injuries, short-term results of reconstruction of the anterior talofibular and calcaneofibular ligaments using bone-split patellar tendon graft were good, with a low frequency of complications.

Adult↗
PubMedDate not supplied

Kinematics and laxity of the knee joint after anterior cruciate ligament reconstruction: pre- and postoperative radiostereometric studies.

BACKGROUND: Injury of the anterior cruciate ligament changes the kinematics of the knee joint. In studies of cadaveric knees, investigators have examined the effect of anterior cruciate ligament reconstruction on knee kinematics, but the effect on dynamic knee motion is not known. HYPOTHESIS: Reconstruction of the anterior cruciate ligament restores knee kinematics to normal. STUDY DESIGN: Prospective cohort study. METHODS: Nine patients were examined preoperatively and 1 year after reconstruction. Continuous radiostereometric exposures were performed at a speed of two to four exposures per second while the patients ascended an 8-cm high platform. Tibial rotation and tibial and femoral translation were measured with radiostereometric analysis. RESULTS: Tibial rotation and tibial and femoral translation were not significantly different after anterior cruciate ligament reconstruction compared with preoperative measurements. A radiostereometric evaluation of anterior knee laxity revealed restoration to within 1 mm of that on the uninjured side. Further evaluation of knee function using the Lysholm score, the Tegner activity level score, the International Knee Documentation Committee evaluation system score, and measurements of laxity using the KT-1000 arthrometer revealed significant improvements after reconstruction. CONCLUSION: Kinematics of the anterior cruciate ligament injured knee did not change significantly after ligament reconstruction, but the functional results were satisfactory and knee laxity was diminished.

Adolescent↗
PubMedDate not supplied

Radiographic and histologic analysis of the tibial tunnel after allograft anterior cruciate ligament reconstruction in goats.

BACKGROUND: Several problems have been reported with use of allogenic grafts in anterior cruciate ligament reconstruction, including local immune response to allograft tendon within the synovial fluid, delayed maturation and ligamentization, and progressive tibial tunnel enlargement. HYPOTHESIS: There is a correlation between the use of allograft and tibial tunnel enlargement. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty healthy adult female goats underwent allograft anterior cruciate ligament reconstruction and were followed with serial radiographs at 6-week intervals. Animals were randomly chosen for sacrifice between 18 and 36 weeks for histologic assessment. RESULTS: Significant radiographic increases in tunnel size were noted within the first 6 weeks of healing and remained up to 36 weeks with no further remodeling noted. Histologic analysis showed progressive ligamentization of the allografts with tendon-to-tunnel wall biologic fixation with dense connective tissue. Remodeling and incorporation of the bone plug was seen in all cases. The allograft tendon underwent early fibrous attachment within the tunnel and remodeled toward ligament histologic structure. Remodeling and incorporation of the bone plug was seen by 18 weeks. CONCLUSION: Tibial tunnel enlargement, consistent with that seen in humans after allograft anterior cruciate ligament reconstruction, did not appear to affect the ultimate incorporation of the allograft on a histologic level.

Animals↗
PubMedDate not supplied

Changes in bone scans after anterior cruciate ligament reconstruction: a prospective study.

BACKGROUND: Whether anterior cruciate ligament reconstruction retards the progression of osteoarthrosis is not established. Bone scintigraphy can be useful for monitoring the course of osteoarthrosis. Bone scan findings are abnormal in the majority of patients with anterior cruciate ligament deficiency. Three uptake patterns can be distinguished. HYPOTHESIS: Reconstruction corrects the three abnormal bone scan patterns seen in patients with anterior cruciate ligament deficiency. STUDY DESIGN: Prospective cohort study. METHODS: We performed bone scintigraphy in 80 patients, before and 2 years after anterior cruciate ligament reconstruction. RESULTS: Reconstruction consistently corrected type 2 bone scan pattern (meniscus scan) but not type 1 and 3 patterns (osteoarthrosis and cartilage ulcer scan). Correction of all three patterns decreased among patients who had longer duration of anterior cruciate ligament deficiency and was more reliable for the combined uptake of all three patterns among patients who had less than 6 months of deficiency. CONCLUSION: These findings indicate anterior cruciate ligament reconstruction protects the menisci. Reconstruction may be best performed within 6 months after injury.

Adolescent↗
PubMedDate not supplied

The effect of anterior cruciate ligament deficiency and functional bracing on translation of the tibia relative to the femur during nonweightbearing and weightbearing.

BACKGROUND: Much of what is known about functional bracing is derived from studies of the knee during unweighted or weightbearing conditions, whereas little is known about the transition between these postures. HYPOTHESIS: Bracing the anterior cruciate ligament-deficient knee during nonweightbearing, throughout the transition to weightbearing, and during weightbearing reduces the abnormal translations of the tibia relative to the femur to within the limits of normal. STUDY DESIGN: Controlled laboratory study. METHODS: Subjects with chronic anterior cruciate ligament tears were studied with and without braces. Anteroposterior shear and compressive loads were applied to the knee, and translations of the tibia relative to the femur were measured while subjects were nonweightbearing, throughout the transition to weightbearing, and during weightbearing. RESULTS: Bracing the anterior cruciate ligament-deficient knee resulted in a significant reduction of anteroposterior laxity values, to a level within the limits of the normal knee during nonweightbearing and weightbearing postures. In contrast, when the anterior cruciate ligament-deficient knees transitioned from nonweightbearing to weightbearing, the anterior translation of the tibia relative to the femur was 3.5 times greater than in the normal knee, and bracing did not reduce this to within the limits of normal. CONCLUSIONS: Bracing a knee with a chronic anterior cruciate ligament tear was effective in reducing abnormal anteroposterior laxity during nonweightbearing and weightbearing; however, braces were not effective in reducing the abnormal anterior translations produced by the change between these postures. CLINICAL RELEVANCE: This study explains why subjects with anterior cruciate ligament tears gain partial control of pathologic anteroposterior laxity with the use of a brace but may continue to experience abnormal translations during activity.

Adult↗
PubMedDate not supplied

Lack of hormonal influences on mechanical properties of sheep knee ligaments.

BACKGROUND: The number of anterior cruciate ligament injuries in female athletes exceeds that in male athletes at similar competitive levels. This difference has been attributed by some authors to hormone-mediated alteration in knee laxity in women. HYPOTHESIS: Sheep anterior cruciate and medial collateral ligament strength and stiffness are not altered by administration for 6 months of estrogen or a selective estrogen receptor agonist (raloxifene). STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-eight mature ewes were divided into five groups: sham operation (N = 6), ovariectomy (N = 9), ovariectomy and estradiol implant (N = 7), low-dose raloxifene (N = 9), and high-dose raloxifene (N = 7). After 6 months, the animals were sacrificed and ligaments were tested along with those from five rams' knees. RESULTS: No differences were found between treatment groups for maximum force, stiffness, energy to failure, or failure site. The ultimate stress of the rams' anterior cruciate ligaments was significantly higher than that of the ewes. CONCLUSIONS: Estrogen and estrogen receptor agonists at physiologic levels do not lead to decreased knee ligament strength. CLINICAL RELEVANCE: The female hormonal milieu may not be responsible for the increased incidence of anterior cruciate ligament injury in female athletes compared with their male counterparts.

Animals↗
PubMedDate not supplied

The effects of compressive load and knee joint torque on peak anterior cruciate ligament strains.

BACKGROUND: High graft strains incurred during rehabilitation after anterior cruciate ligament reconstruction may be minimized if an external compressive load is simultaneously applied to the joint during closed kinetic chain exercises. HYPOTHESES: Peak anterior cruciate ligament strains will 1). increase with an increase in resistance torque during an exercise that involves concentric contraction of the extensor mechanism, 2). decrease with an increase in resistance torque during an exercise that involves concentric contraction of the flexors, and 3). decrease when an external compressive load is applied to the knee during both exercises relative to the no external compressive load condition. STUDY DESIGN: Controlled laboratory study. METHODS: Strains in the anteromedial bundle were measured in 10 subjects with normal ligaments. Flexor and extensor exercises were performed against controlled resistance torques with and without a compressive load applied to the foot. RESULTS: An increase in resistance produced an increase in peak anterior cruciate ligament strain for the extensor exercise with no compressive load applied. During the flexor exercise without a compressive load, an increase in resistance produced a decrease in peak strains. During the extensor exercise, the peak anterior cruciate ligament strain was not reduced with the application of the external compressive force. CONCLUSIONS: Extensor and flexor exercises that incorporate an external compressive load do not shield the anterior cruciate ligament from strain. However, no additional increase in strain occurs with an increase in resistance when the external compressive load is applied. Thus, it may be possible to increase the activity of the quadriceps muscles without increasing the strain by applying a compressive load (as with closed kinetic chain exercises).

Adult↗