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PubMedDate not supplied

MR imaging evaluation of knee collateral ligaments and related injuries: comparison of T1-weighted, T2-weighted, and fat-saturated T2-weighted sequences--correlation with clinical findings.

The objectives of this study were to compare the ability of T1-weighted (T1W), proton density/T2-weighted (PD/T2W), and fat saturation (FS) PD/T2W magnetic resonance (MR) sequences for depiction of the knee collateral ligaments and related injuries, and to compare MR findings with clinical findings. Ten subjects with normal knee ligaments and 64 patients with suspected collateral ligament injuries underwent coronal T1W, PD/T2W, and FS PD/T2W imaging. Abnormalities ranged from edema surrounding the collateral ligaments (grade I) to complete disruption of ligamentous fibers (grade III). FS PD/T2W images improved definition of the medial collateral ligament (MCL) and lateral collateral ligament (LCL) compared with other sequences in 78% and 81% of patients, respectively. While the apparent grade of collateral ligament injury was similar with all pulse sequences in most patients, depiction of such injury was usually most conspicuous on FS PD/T2W images (MCL, 92% of patients; LCL, 38% of patients). In no patients were clinically diagnosed collateral ligament injuries undetected or understaged with MR imaging. MR findings indicated higher-grade MCL and LCL injuries than did clinical examination in 24 and 15 patients, respectively.

Adipose Tissue↗
PubMed2000

Proteoglycan metabolism during repair of the ruptured medial collateral ligament in skeletally mature rabbits.

The metabolism of the chondroitin/dermatan sulfate (CS/DS) proteoglycans (PGs) decorin and biglycan is markedly altered during short-term (3-6 weeks) and long-term (40 weeks-2 years) repair of surgically ruptured medial collateral ligaments from mature rabbits. A PG-rich extracellular matrix accumulates in injury gaps by 3 weeks postsurgery and extends into tissue regions containing the original ligaments, and elevated PG levels remain apparent up to 2 years postinjury. CS/DS PGs were prepared from such ligaments and identified after SDS-polyacrylamide gel electrophoresis by Alcian blue staining or immunoblotting. In normal ligaments, decorin is the most abundant proteoglycan (accounting for approximately 80% of the total); the remainder is biglycan and a large PG, possibly versican. In repairing ligaments, decorin is barely detected, but instead a large proteoglycan and abundant amounts of biglycan accumulate. Biglycan is present in two forms in repairing ligaments, and they can be separated on SDS-PAGE into 200- and 140-kDa forms. The slower migrating species is absent in normal ligaments and may represent a different glycoform (containing either a single or two short chondroitin/dermatan sulfate chains) of biglycan. Alteration in PG expression and posttranslational processing during medial collateral ligament repair are similar to those reported for repair and scar formation of other connective tissues. The accumulation of biglycan observed here may interfere with proper collagen network remodeling and may lead to persistent inflammatory and matrix turnover processes, thus preventing restoration of a long-term functional ligament tissue.

Animals↗
PubMed2002

[History of surgery of the anterior cruciate ligament].

Early comments on the anterior cruciate ligament were found in ancient literature, and the first scientific reports were published in the nineteenth century. The first surgical treatment of a ruptured anterior cruciate ligament was carried out in 1895 by Robson performing a primary suture of the torn ligament. In 1903 F. Lange suggested a complete replacement of the injured ligament using silk ligaments and in 1914 Grekow was probably the first who recommended autogenous transplants by using a fascia lata strip. In 1917 Hey-Groves presented his surgical technique that was the fundament for reconstruction surgery in the following years. Today, the autogenous transplant is accepted to be the golden standard for replacement of the injured anterior cruciate ligament. The bone-tendon-bone transplant of the patellar ligament and the semitendinosus or gracilis tendon are recommended by most surgeons. In the history of anterior cruciate ligament surgery, the surgical technique of the operative procedures has also changed. The evolution started with open arthrotomy followed by mini-arthrotomy and led to arthroscopically assisted replacement of the anterior cruciate ligament.

Anterior Cruciate Ligament↗
PubMed2001

MR imaging of the anterior intermeniscal ligament: classification according to insertion sites.

Our objective was to study the frequency of anterior intermeniscal ligament on MR imaging and to make a classification according to its insertion sites on MR images. Sagittal T1-weighted and thin-section transverse T2*-weighted MR images of the knee were prospectively evaluated in 229 subjects without significant synovial effusion or total rupture of the anterior cruciate ligament. By using thin-section transverse images, the ligament was classified into three types according to its insertion sites (type A: between anterior horns of medial and lateral menisci; type B: between anterior horn of medial meniscus and anterior margin of lateral meniscus; type C: between anterior margins of medial and lateral menisci). On sagittal images location of the ligament was determined with respect to a line drawn between anterior of the tibial epiphysis and posterior of the intercondylar notch to look for a relation between its type on transverse images and location on sagittal images. Separately, arthroscopy was made in 36 patients to verify the MR assessment of the presence of the ligament. Anterior intermeniscal ligament was found in 53% of the subjects. Type B was the most common group (58%). Magnetic resonance imaging has a sensitivity and a specificity of 67 and 100%, respectively, in the detection of the ligament. Types A and C had a statistically significant location posterior and anterior, respectively, to the master line on sagittal images. In arthroscopy, the ligament was either cord-like (67%) or flat (33%) in appearance. Routine sagittal MR images can help identify anterior intermeniscal ligament.

Adult↗
PubMed2001

High-speed subfailure stretch of rabbit anterior cruciate ligament: changes in elastic, failure and viscoelastic characteristics.

OBJECTIVE: To study alterations in the ligament mechanical characteristics due to a subfailure stretch delivered at high speed. DESIGN: An in vitro study of rabbit anterior cruciate ligaments. BACKGROUND: Although ligamentous sprains occur more frequently than the complete failures, only a few biomechanical studies have investigated the effects of such injuries. Purpose of the study was to document changes in elastic, failure and viscoelastic properties of a ligament that had been subjected to a high-speed subfailure stretch. METHODS: Thirteen paired fresh adult rabbit femur-anterior cruciate ligament-tibia preparations were used. One ligament of each pair (control) was subjected to two relaxation tests and then stretched until failure. The other ligament (experimental) was subjected sequentially to relaxation test, subfailure stretch (80% of the failure deformation of the control), relaxation test, and then stretched until failure. Load-deformation curve until failure was characterized by nine parameters, which included failure force, deformation and energy absorbed, and deformations measured at various load values, and stiffness. Relaxation curve was parameterized by five relaxation forces measured at 10, 30, 50, 130, and 180 s. RESULTS: Due to subfailure stretch, there were no changes in failure force and stiffness, while deformations increased, and energy absorbed and relaxation forces decreased. CONCLUSIONS: The 80% subfailure stretch delivered at high speed increased the deformations in load-deformation tests, and decreased the forces in relaxation tests. Relevance. Incomplete injuries of the ligaments are more prevalent than the complete injuries. The incomplete injury is a subfailure stretch delivered at high speed. The present study provides the results of simulating the incomplete injury using an in vitro ligament model.

Animals↗
PubMed2003

Biomechanical evaluation of a newly devised model for the elongation-type anterior cruciate ligament injury with partial laceration and permanent elongation.

OBJECTIVE: To biomechanically evaluate a newly devised model for the elongation-type anterior cruciate ligament injury with partial laceration and permanent elongation. DESIGN: Thirty-six rabbits were randomly divided into 4 groups of 9 animals each, after a quantitative injury was given to the right anterior cruciate ligament. The 4 groups were sacrificed at 0, 6, 12, and 24 weeks after surgery, respectively. Biomechanical and histological evaluations were performed at each period. BACKGROUND: No adequate animal models have been established for the elongation-type anterior cruciate ligament injury in which the mid-substance is permanently elongated with partial laceration. METHODS: The anteromedial and posterolateral half of the anterior cruciate ligament was transected at the proximal and distal one-third levels, respectively. Then, the anterior cruciate ligament was stretched by applying an anterior drawer force to the tibia at 90 degrees of knee flexion. RESULTS: The treatment significantly increased the anterior translation of the knee into approximately 150-250% at each period after surgery. The maximum load and the stiffness of the femur-anterior cruciate ligament-tibia complex significantly decreased to 30% or less immediately after surgery, and then gradually increased to 50% at 12 weeks. CONCLUSIONS: In this model, this quantitative treatment created serious injuries with partial laceration and permanent elongation in the anterior cruciate ligament to similar degrees. Also, incomplete tissue healing occurred in the anterior cruciate ligament to similar degrees after the treatment. RELEVANCE: This model will be useful to study new therapeutic methods for the elongation-type anterior cruciate ligament injury.

Animals↗
PubMed2002

Type II collagen deposition in cruciate ligament precedes osteoarthritis in the guinea pig knee.

OBJECTIVE: To examine the collagens in cruciate ligaments of young Dunkin-Hartley guinea pigs, to determine whether a change in specific collagen types is an early feature of the spontaneous osteoarthritis (OA), which consistently develops in the medial compartment of the knee in this strain. DESIGN: Collagen types I, II, III, IX, and XI were detected by immunofluorescence microscopy in the anterior and posterior cruciate ligaments of animals at 3, 4-5 and 12 weeks of age. Type II collagen in PCL was further analysed by confocal microscopy or biochemical assay after cyanogen bromide digestion, SDS-PAGE and immunoblotting. Interfibrillar proteoglycans were visualized by transmission electron microscopy. RESULTS: Collagen types I and III formed the bulk of fibrous mid-ligament tissue in all animals. Typical cartilage collagens, types II, IX and XI, were identified by immunolabeling where ligaments attached to tibial bone. Type II collagen, normally restricted to the fibrocartilage attachment sites, was also found at separate foci in anterior fiber bundles of the posterior cruciate ligament in 12-week-old animals. Biochemical data confirmed these observations which, together with electron microscopy showing large atypical proteoglycan structures, suggested the deposition of fibrocartilage within the fibrous mid-ligament. CONCLUSIONS: Cruciate ligaments, especially posterior cruciate ligament in Dunkin-Hartley guinea pigs synthesize cartilage-like matrix in mid-ligament prior to the appearance of classical signs of OA.

Aging↗
PubMed2001

Long-term results of the anterior floating method for cervical myelopathy caused by ossification of the posterior longitudinal ligament.

STUDY DESIGN: Results of the anterior floating method used to decompress ossification of the posterior longitudinal ligament were studied for an average postoperative interval of 13 years. OBJECTIVE: To investigate the long-term results of the anterior floating method used to manage ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: The anterior floating method is a technique that differs from the extirpation method used to manage ossification of the posterior longitudinal ligament. Reports of the long-term results from anterior decompression used to manage cervical ossification of the posterior longitudinal ligament are rare. METHODS: The anterior floating method was used to decompress cervical ossification of the posterior longitudinal ligament in 63 patients. These patients were followed for more than 10 years with neurologic evaluations using a scoring system proposed by the Japanese Orthopedic Association (JOA score). RESULTS: The recovery rate was 66.5% at 10 years and 59.3% at 13 years, the time of the final survey. Operative outcomes most closely reflected the preoperative duration and severity of myelopathy (JOA score) and the preoperative cross-sectional area of the spinal cord. There was no correlation with the canal narrowing ratio or the thickness of ossification of the posterior longitudinal ligament. Delayed deterioration was attributed to an original inadequate decompression and progression of ossification of the posterior longitudinal ligament outside the original operative field. There was no evidence of significant recurrent ossification of the posterior longitudinal ligament within the margins of prior decompression. CONCLUSIONS: The anterior floating method appears to yield adequate long-term outcomes when used to manage ossification of the posterior longitudinal ligament.

Adult↗
PubMed1997

Postnatal development of the cruciate ligament insertions in the rat knee. morphological evaluation and immunohistochemical study of collagens types I and II.

The postnatal structural remodelling and calcification patterns in the insertions (entheses) of both cruciate ligaments were studied in a rat model with histology and immunohistochemical analysis of collagens types I and II. In the neonate, both ligaments which labelled only for type I collagen attached to epiphyseal cartilage which solely labelled for collagen type II. The entheses calcified between days 20 and 35, and a subchondral bone plate formed under the entheses between days 30 and 55. Thus, within a period of 35 days the tissue to which the ligaments attached increased multifold in stiffness. Interestingly, the process of enthesial calcification and formation of compact bone did not happen simultaneously in both ligaments, not even synchronous at both ends of the same ligament or within a single insertion. This asynchronous calcification of the different knee ligament insertions may make the sudden change in mechanical environment at the entheses less dramatic for the ligaments and knee joint surfaces as anticipated from mechanical models. In addition, a fibrocartilaginous tissue, rich in collagen type II, formed in the ligament at a time when the epiphyseal cartilage was replaced by bone, and grew wider with time. The interposition of a fibrocartilaginous zone in the insertion may diminish the sudden change in stiffness between ligament soft tissue and hard bone.

Animals↗
PubMedDate not supplied

Change in meniscal strain with anterior cruciate ligament injury and after reconstruction.

Meniscal injury has been well documented in association with injury to the anterior cruciate ligament. The purpose of this study was to evaluate the effect of anterior cruciate ligament transection and reconstruction on meniscal strain. Four differential variable reluctance transducer strain gauges were placed in the medial and lateral menisci of nine cadaveric knees. Each specimen was mounted to a six-degree-of-freedom knee testing device. Testing was conducted with the knee fully extended and at 45 degrees and 90 degrees of flexion, both with and without applied axial load. At each angle of flexion, an anterior and posterior tibial load was applied. Next, the anterior cruciate ligament was transected and the testing sequence was repeated. Finally, the ligament was reconstructed using a central one-third patellar tendon graft and the testing sequence was repeated. The results demonstrated statistically significant increases in meniscal strain in ligament-transected knees compared with intact specimens. A reduction in meniscal strain to a level similar to that detected in the ligament-intact knees was observed after anterior cruciate ligament reconstruction. These results have important clinical implications regarding the potentially deleterious effect of the anterior cruciate ligament-deficient knee on meniscal strain and the potential benefit of anterior cruciate ligament reconstruction.

Aged↗
PubMedDate not supplied

The effect of exercise on anterior-posterior translation of the normal knee and knees with deficient or reconstructed anterior cruciate ligaments.

Exercise may result in increased laxity in the knee. Anterior translation in 40 normal knees, 33 consecutive anterior cruciate ligament-deficient knees, and 30 randomly chosen anterior cruciate ligament-reconstructed knees was measured using the KT-1000 arthrometer before and after the participants ran for 15 minutes on a neutral-incline treadmill. A single observer blinded to the status of each knee tested all participants. There was a significant increase in anterior translation in the normal (mean, 0.75 mm), anterior cruciate ligament-deficient (mean, 0.62 mm), and anterior cruciate ligament-reconstructed knees (mean, 0.25 mm) after exercise. In addition, the amount of anterior translation after exercise was significantly different when these groups were compared with each other. Post hoc analysis using Tukey's procedure indicated that anterior translation in the anterior cruciate ligament-reconstructed knee was significantly less than in the normal and anterior cruciate ligament-deficient knees. Therefore, repetitive loading exercise contributes to an increase in anterior translation in normal, anterior cruciate ligament-deficient, and anterior cruciate ligament-reconstructed knees, and the anterior cruciate ligament-reconstructed knee does not respond to repetitive loading in the same manner as a normal knee.

Adolescent↗
PubMedDate not supplied

Relaxin receptors in the human female anterior cruciate ligament.

BACKGROUND: Noncontact anterior cruciate ligament injuries occur two to eight times more often in women than in men. Changes in ligament laxity and strength have been associated with female hormones such as relaxin. HYPOTHESIS: Relaxin receptors are present within the female anterior cruciate ligament. STUDY DESIGN: Controlled laboratory study. METHODS: Remnants of anterior cruciate ligament were harvested from five women and five men undergoing routine ligament reconstruction. Relaxin was biotinylated and analyzed for biologic activity with use of the mouse interpubic ligament bioassay. Immunohistochemical localization of relaxin receptors was performed with appropriate negative controls and competitive binding assays to determine receptor specificity and saturability. RESULTS: Anterior cruciate ligament sections from women but not from men showed uniform specific binding that was limited to synovial lining cells, stromal fibroblasts, and cells lining blood vessels. Specific binding was confirmed in the presence of a 2000-fold excess of human insulin, the structural homolog of relaxin, and competitive inhibition was demonstrated in the presence of a 2000-fold excess of unlabeled relaxin. CONCLUSIONS: Relaxin exhibits specific saturable binding in the female anterior cruciate ligament, where specific relaxin receptors were present. CLINICAL RELEVANCE: The high incidence of anterior cruciate ligament rupture in female athletes may be partially explained by the effects of relaxin.

Adolescent↗
PubMedDate not supplied

The effect of estrogen on ovine anterior cruciate ligament fibroblasts: cell proliferation and collagen synthesis.

UNLABELLED: Estrogen has been implicated as a causal factor for anterior cruciate ligament injuries in women. Studies have demonstrated a decrease in anterior cruciate ligament fibroblast proliferation and collagen synthesis at supraphysiologic levels of estrogen in a rabbit model. HYPOTHESIS: The authors hypothesized that physiologic levels of estrogen would have no significant effect on anterior cruciate ligament fibroblast proliferation and collagen synthesis in an ovine model. METHODS: Anterior cruciate ligament fibroblasts were isolated from sheep knees using routine cell culture methods. The cells were exposed to 17beta-estradiol at physiologic concentrations of 2.2, 5, 15, 25, 250, and 2500 pg/ml. Cell proliferation was determined by cell counts on days 4 and 6. Collagen synthesis was determined by (3)H-proline incorporation on day 4. Immunohistochemistry was performed to detect estrogen receptors. RESULTS: Immunohistochemistry demonstrated the presence of estrogen receptors in ovine anterior cruciate ligament fibroblasts. There was no significant difference in anterior cruciate ligament fibroblast proliferation or collagen synthesis regardless of 17beta-estradiol concentration. CONCLUSIONS: Based on results of this study, and given the low turnover of collagen in ligaments, it is unlikely that a 2- to 3-day per month increase in circulating estrogen would result in rapid, clinically significant alterations in material properties of the anterior cruciate ligament in vivo. The etiology of noncontact anterior cruciate ligament injuries is complex and multifactorial in nature, meriting further investigation.

Animals↗
PubMed2004

Effects of applied quadriceps and hamstrings muscle loads on forces in the anterior and posterior cruciate ligaments.

BACKGROUND: Muscle contraction can subject healing knee ligament grafts to high loads. PURPOSE: To directly measure the effects of quadriceps and hamstrings muscle loads on forces in the anterior cruciate ligaments and posterior cruciate ligaments. STUDY DESIGN: Controlled laboratory study. METHODS: Thirteen cadaveric knee specimens had load cells installed to record resultant forces in both anterior and posterior cruciate ligaments under 5 loading conditions. Cruciate force measurements were repeated with a 100-N load applied to the quadriceps tendon and again with a combined 50-N biceps load and 50-N semimembranosus-semitendinosus load. RESULTS: Applied quadriceps loads resulted in mean changes in anterior cruciate ligament and posterior cruciate ligament forces that were less than 20 N for all loading conditions. Hamstrings load significantly increased mean posterior cruciate ligament force between 30 degrees and 105 degrees of flexion with 100 N of applied posterior tibial force. CONCLUSIONS: At the muscle force levels used in this study, the hamstrings were more effective than the quadriceps in altering cruciate force levels, especially near 90 degrees of flexion, where they have an excellent mechanical advantage for controlling anterior-posterior tibial translation. CLINICAL RELEVANCE: Isolated hamstrings activity generally had little or no effect on anterior cruciate ligament forces but significantly increased forces in the posterior cruciate ligament beyond approximately 30 degrees of flexion.

Adult↗
PubMed2005

The effect of anterior cruciate ligament reconstruction on knee joint kinematics under simulated muscle loads.

BACKGROUND: Numerous studies have investigated anterior stability of the knee during the anterior drawer test after anterior cruciate ligament reconstruction. Few studies have evaluated anterior cruciate ligament reconstruction under physiological loads. PURPOSE: To determine whether anterior cruciate ligament reconstruction reproduced knee motion under simulated muscle loads. STUDY DESIGN: Controlled laboratory study. METHODS: Eight human cadaveric knees were tested with the anterior cruciate ligament intact, transected, and reconstructed (using a bone-patellar tendon-bone graft) on a robotic testing system. Tibial translation and rotation were measured at 0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees of flexion under anterior drawer loading (130 N), quadriceps muscle loading (400 N), and combined quadriceps and hamstring muscle loading (400 N and 200 N, respectively). Repeated-measures analysis of variance and the Student-Newman-Keuls test were used to detect statistically significant differences between knee states. RESULTS: Anterior cruciate ligament reconstruction resulted in a clinically satisfactory anterior tibial translation. The anterior tibial translation of the reconstructed knee was 1.93 mm larger than the intact knee at 30 degrees of flexion under anterior load. Anterior cruciate ligament reconstruction overconstrained tibial rotation, causing significantly less internal tibial rotation in the reconstructed knee at low flexion angles (0 degrees-30 degrees) under muscle loads (P < .05). At 30 degrees of flexion, under muscle loads, the tibia of the reconstructed knee was 1.9 degrees externally rotated compared to the intact knee. CONCLUSIONS: Anterior cruciate ligament reconstruction may not restore the rotational kinematics of the intact knee under muscle loads, even though anterior tibial translation was restored to a clinically satisfactory level under anterior drawer loads. These data suggest that reproducing anterior stability under anterior tibial loads may not ensure that knee joint kinematics is restored under physiological loading conditions. CLINICAL RELEVANCE: Decreased internal rotation of the knee after anterior cruciate ligament reconstruction may lead to increased patellofemoral joint contact pressures. Future anterior cruciate ligament reconstruction techniques should aim at restoring 3-dimensional knee kinematics under physiological loads.

Anterior Cruciate Ligament↗
PubMed2006

The 6 degrees of freedom kinematics of the knee after anterior cruciate ligament deficiency: an in vivo imaging analysis.

BACKGROUND: Previous studies of knee joint function after anterior cruciate ligament deficiency have focused on measuring anterior-posterior translation and internal-external rotation. Few studies have measured the effects of anterior cruciate ligament deficiency on 6 degrees of freedom knee kinematics in vivo. OBJECTIVE: To measure the 6 degrees of freedom knee kinematics of patients with anterior cruciate ligament deficiency. STUDY DESIGN: Controlled laboratory study. METHODS: The knee joint kinematics of 8 patients with unilateral anterior cruciate ligament rupture was measured during a quasi-static lunge. Kinematics was measured from full extension to 90 degrees of flexion using imaging and 3-dimensional modeling techniques. The healthy, contralateral knee of each patient served as a control. RESULTS: Anterior cruciate ligament deficiency caused a statistically significant anterior shift (approximately 3 mm) and internal rotation of the tibia (approximately 2 degrees ) at low flexion angles. However, ligament deficiency also caused a medial translation of the tibia (approximately 1 mm) between 15 degrees and 90 degrees of flexion. CONCLUSION: The medial shift of the tibia after anterior cruciate ligament deficiency might alter contact stress distributions in the tibiofemoral cartilage near the medial tibial spine. These findings correlate with the observation that osteoarthritis in patients with anterior cruciate ligament injuries is likely to occur in this region. CLINICAL RELEVANCE: The data from this study suggest that future anterior cruciate ligament reconstruction techniques should reproduce not only anterior stability but also medial-lateral stability.

Adult↗
PubMed2006

Revision anterior cruciate ligament reconstruction with hamstring tendon autograft: 5- to 9-year follow-up.

BACKGROUND: The results of revision anterior cruciate ligament reconstruction are limited in the current literature, and no studies have previously documented the outcome of revision anterior cruciate ligament reconstruction using solely hamstring tendon grafts. HYPOTHESIS: Revision anterior cruciate ligament reconstruction with 4-strand hamstring tendon graft affords acceptable results and is comparable to reported outcomes with the bone-patellar tendon-bone graft. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Fifty-seven consecutive revision anterior cruciate ligament reconstructions with the hamstring tendon graft and interference screw fixation were assessed a mean time of 89 months (range, 60-109 months) after surgery. Assessment included the International Knee Documentation Committee knee ligament evaluation, instrumented laxity testing, and radiologic examination. RESULTS: Of the 50 knees reviewed, 5 (10%) had objective failure of the revision anterior cruciate ligament reconstruction. Of the 45 patients with functional grafts, knee function was normal or nearly normal in 33 patients (73%). An overall grade of normal or nearly normal was found in 56% of patients. The mean side-to-side difference on manual maximum testing was 2.5 mm (range, -1 to 4 mm). Degenerative changes on radiographs were identified in 23% of patients at the time of surgery, increasing to 56% of patients at review. The status of the articular cartilage at the time of revision surgery was the most significant contributor to successful outcome. CONCLUSION: Revision anterior cruciate ligament reconstruction with hamstring tendon graft and interference screw fixation affords acceptable results at a minimum of 5 years' follow-up. Good objective results can be obtained, but subjectively, the results appear inferior to those of primary anterior cruciate ligament reconstruction in the literature, which may be related to the high incidence of articular surface damage in this patient population. We recommend that, when available, hamstring tendon autografts should be considered for revision anterior cruciate ligament reconstruction.

Adolescent↗
PubMedDate not supplied

Impact biomechanics of lateral knee bracing. The anterior cruciate ligament.

We evaluated the effects of six different prophylactic braces on ACL ligament strain under dynamic valgus loads using a mechanical surrogate limb validated against human cadaveric specimens. Medical collateral ligament and anterior cruciate ligament peak forces, medial collateral ligament and anterior cruciate ligament tension initiation times, and impact safety factors were calculated for both braced and unbraced conditions. These tests were conducted to determine whether or not application of a prophylactic brace might provide protection to the anterior cruciate ligament under valgus loading conditions. The results of this study indicate that those braces that increased impact duration appear to differentially protect the anterior cruciate ligament more than the medial collateral ligament, and that most of the braces tested appear to provide some degree of protection to the anterior cruciate ligament under direct lateral impacts. These findings should be confirmed clinically.

Anterior Cruciate Ligament↗