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A quantitative comparison of collagen phagocytosis in periodontal ligament and transseptal ligament of the rat periodontium.

The phagocytosis of collagen within soft connective tissues can be used as an index of collagen turnover and remodeling. The objective of this study was to compare the levels of collagen phagocytosis in periodontal and transseptal ligaments in the rat in order to provide an indication of the relative collagen-turnover activities within these two tissues. Periodontal and transseptal ligaments from two rats were examined by the techniques of electron microscope stereology. Parameters quantitated included cytoplasm (CC), extracellular collagen (ECC), and intracellular or phagocytosed collagen (ICC). The results indicated that the cells of the transseptal ligament have significantly more ICC than those of periodontal ligament. This suggests that the transseptal ligament in the rat may have a high rate of collagen turnover. There seems to be an increasing body of evidence, including the present results, that the transseptal ligament region of gingiva has a high level of collagen turnover. It seems likely, therefore, that, unless there are marked species differences in collagen turnover, slow remodeling of the transseptal ligament is not responsible for orthodontic relapse. Why relapse of rotated teeth can be reduced by surgical severing or removal of the transseptal tissue remains to be determined.

Animals↗

Biomechanical properties of spinal ligaments and a histological study of the supraspinal ligament in traction.

This paper reports the results of a biomechanical study of 43 human spinal ligaments from fresh cadavers and living subjects. Tensile tests were performed with an original testing machine. The tension load and relaxation were applied at the same constant slow rate (1 mm min-1) on entire ligaments. In order to avoid ligament injuries, fixation in the apparatus was on the bone held in clamps specifically designed for each bone, never the ligament itself or its bony attachments. All the load-deformation curves had a sigmoid shape and during load-unload cycles ligaments exhibited elastic properties. This was particularly evident for the ligamentum flavum. The intertransverse posterior longitudinal ligament and the ligamentum flavum were the most resistant. The elongation-tension curve pattern may be explained by the microscopic architectural change that was studied in supraspinous ligament.

Adult↗

Variation in anterior cruciate ligament scar pattern: does the scar pattern affect anterior laxity in anterior cruciate ligament-deficient knees?

PURPOSE: This prospective study documented patterns of scar formation after anterior cruciate ligament (ACL) rupture in order to test the hypothesis that ACL remnants can contribute to anterior knee passive motion limits tested with a ligament arthrometer. TYPE OF STUDY: Prospective cohort study. METHODS: Forty-eight consecutive patients undergoing ACL reconstructions had intra-operative ligament arthrometry testing before and immediately after preparation of the notch and debridement of the ACL remnant. Patterns of scar formation were compared with changes in knee laxity after debridement of the ACL remnant. RESULTS: Eighteen patients (38%) had ligament scarring to the posterior cruciate ligament (group 1). Four patients (8%) had scar tissue that appeared to extend from the ACL fibers to the roof of the notch (group 2). Six ACL remnants (12%) appeared to have healed to the lateral wall of the notch or the medial aspect of the lateral femoral condyle in a position anterior and distal to the ACL anatomic footprint (group 3). In 20 patients (42%), there was no identifiable ligament tissue remaining (group 4). Changes in anterior laxity were associated with the specific pattern of scar formation within the notch. The greatest increase in anterior laxity after debridement was observed in knees in which the injured ACL had an aberrant reattachment to the femur: group 1 (mean, -1.3 mm; P < .01), group 2 (mean, -3.4 mm; P < .05), and group 3 (mean, -4.3 mm; P < .05). In group 4, the change in knee laxity was not significant (mean, 0.2 mm; 95% CI, -0.29 to 0.74 mm). Overall, 14 of 48 knees (29%) loosened more than 2 mm after ACL resection ( P < .01). CONCLUSIONS: Resection of the ACL scar resulted in a measurable increase in passive anterior laxity in a subset of ACL-deficient knees. This increase in anterior laxity occurred in patients whose ligament healed to the femur, effectively crossing the joint. When performing arthroscopy without reconstruction in ACL-injured knees, we recommend caution in resecting the torn ACL or scar tissue because removal of this tissue contributed to increased anterior laxity in some ACL-deficient knees. LEVEL OF EVIDENCE: Level II, diagnostic study of consecutive patients.

Adult↗

Augmentation of a ruptured posterior cruciate ligament provides normal knee joint stability during ligament healing.

OBJECTIVE: To identify an augmentation technique which would provide mechanical protection for the healing posterior cruciate ligament. DESIGN: Six human knee specimens were tested in vitro for posterior knee joint stability after augmenting the cut posterior cruciate ligament by six different techniques using a resorbable double strand Polydioxanone augmentation device. BACKGROUND: A fresh isolated rupture of the posterior cruciate ligament is often treated conservatively. Results have shown that it can heal, but ligament elongations occur frequently. Therefore a method is needed to provide posterior knee joint stability during ligament healing. METHODS: The effect of different femoral augmentation insertions on posterior knee stability was tested by recording the antero-posterior (AP) position of the tibia and the augmentation force. Testing was performed during flexion--extension cycles and under posterior shear loads. RESULTS: The insertion combination that proved to stabilize the joints best consisted of one augmentation strand leading along the antero-lateral posterior cruciate ligament fibres and inserting at the distal end of the Blumensaat line and one strand leading along the posteriormedial fibres and inserting in the middle of the Blumensaat line. AP translations similar to those occurring in healthy knee joints could be achieved. CONCLUSIONS: It is possible to restore normal posterior knee joint stability by implanting a double strand augmentation device. This can help a posterior cruciate ligament to heal under non-elongated conditions.

Absorbable Implants↗

The lunotriquetral joint: kinematic effects of sequential ligament sectioning, ligament repair, and arthrodesis.

This experiment was conducted to study the effects of sequential sectioning of the ligaments of the lunotriquetral (LT) joint and the effects of simulated repair or arthodesis on kinematics of the wrist joint using an x-ray stereophotogrammetric technique. A 3-dimensional coordinate software program calculated relative motion between bodies as screw axis displacement and rotation about each axis. Sectioning of the proximal and dorsal component of the LT ligament had little effect on carpal kinematics, but sectioning of the proximal and palmar components of the ligament resulted in flexion of both the lunate and triquetrum, producing a volar intercalated segment instability (VISI) pattern. The triquetrum supinated away from the lunate after sectioning of the entire LT ligament. Greater VISI occurred after sectioning the dorsal radiotriquetral and scaphotriquetral ligaments. Progressive destabilization of the LT joint results in increasing kinematic alterations; however, these may not exactly mimic the clinical situation. Moving the wrist through 1,000 cycles increased the instability. Dorsal repair of the LT ligament realigned the lunate and triquetrum, and LT fusion corrected triquetral supination. The latter, however, resulted in overcorrection into extension, which prevented a full wrist extension. The repair used may be insufficient to restore the palmar ligamentous integrity. Lunotriquetral arthodesis was difficult to simulate, providing some insight into the cause of clinical nonunions. Severe VISI is not correctable by repair or arthrodesis and requires further study using reconstructive procedures not discussed here.

Adult↗

Anterior cruciate ligament and intercondylar notch in the coronal oblique plane: anatomy complemented by magnetic resonance imaging in cruciate ligament-intact knees.

We assessed the anatomy of the anterior cruciate ligament (ACL) and femoral intercondylar notch on cryosections from one cadaveric knee specimen in the coronal oblique plane oriented parallel to the intercondylar roof. We determined the course of the ACL, the widths of the cruciate ligaments at intersection, and the intercondylar notch configuration on coronal oblique plane magnetic resonance images in 51 adult cruciate ligament-intact knees (25 women, 26 men; age range, 16 to 47 years). The intercondylar notch widths were measured at the notch entrance, at the intersection of the ACL and posterior cruciate ligament (PCL), and at the notch outlet. In the coronal oblique plane, the ACL exhibited a diagonal course from the central and medial part of the anterior intercondylar area of the tibia distally, across the lateral third of the intercondylar notch, to the intercondylar surface of the lateral femoral condyle proximally. At the cruciate ligament intersection, the absolute widths of the ACLs measured on average 6.1+/-1.1 mm in men and 5.2+/-1.0 mm in women representing 31.9% and 31.1% of the ACL/central intercondylar notch width ratios. The absolute widths of the PCLs measured on average 9.6+/-1.3 mm in men and 8.5+/-1.3 mm in women representing 50.4% and 51.4% of PCL/central intercondylar notch width ratios. On average for both groups, men and women, the absolute widths of the PCLs were significantly larger than the absolute widths of the ACLs. However, the relative widths of the cruciate ligaments with respect to corresponding intercondylar notch widths were not significantly different. In the coronal oblique plane, the intercondylar notch widths showed on average a significant decrease from posterior to intersection and from intersection to anterior. At notch outlet, the mean notch width measured 21.4 mm in men and 18.5 mm in women. At intersection, the mean notch width measured 19.1 mm in men and 16.6 mm in women. At notch entrance, the notch width measured 14.6+/-1.8 mm in men and 12.7+/-2.1 mm in women. We recommend magnetic resonance tomography of the knee in the coronal oblique plane oriented parallel to the intercondylar roof as the imaging modality of choice to visualize accurately the anatomic diagonal course of the ACL and its relation to the intercondylar notch and posterior cruciate ligament complex.

Adolescent↗

Anatomicohistologic study of the retaining ligaments of the face and use in face lift: retaining ligament correction and SMAS plication.

Plastic surgeons have sought to improve nasolabial folds, jowls, jaw lines, and cervical contour with face-lifting procedures that are abundant in the literature. The retaining ligaments of the face support facial soft tissue in normal anatomic position, resisting gravitational change. As this ligamentous system attenuates, facial fat descends into the plane between the superficial and deep facial fascia, and the stigmata of facial age develop. In this study, surgical correction of the retaining ligaments and plication of the superficial musculoaponeurotic system (SMAS) to reposition the structures that have descended with gravitation are discussed. The anatomy of the facial retaining ligaments was studied in 22 half-faces of 11 fresh cadavers, and the localization, extension, and width of the ligaments were examined macroscopically and histologically. Surgical correction of the retaining ligaments and plication of the SMAS have been accomplished in 27 face-lift patients with this anatomicohistologic study taken into consideration. There was hematoma in one patient at the cheek region and a permanent dimple caused by postoperative edema in two patients, with a localization of one zygomatic and two parotidomasseteric ligaments. In one patient, hypesthesia in the mandibular nerve region was seen, which remitted at 14 weeks. There were no other complications, and with a follow-up of 24 months, excellent aesthetic results and a high level of patient satisfaction were encountered.

Adult↗

Investigation of periodontal ligament reaction upon excessive occlusal load--osteopontin induction among periodontal ligament cells.

OBJECTIVE: The purpose of the present study was to investigate the reaction of the periodontal ligament to excessive occlusal loading by observing the histological changes and osteopontin induction. The possibility of ligand for receptor activator of nuclear factor kappaB (RANKL) participation in osteopontin induction was also discussed. BACKGROUND: The precise mechanism of periodontal ligament breakdown by excessive occlusal loading remains unclear. We established an experimental model for excessive occlusal loading in vivo. Osteopontin is known to be produced upon mechanical loading and is considered to induce the migration of osteoclasts to the resorption site. RANKL is one of the essential factors for osteoclast maturation and induces the constitutive induction of intracellular osteopontin in vitro. METHODS: The occlusal surface of the upper left first molars of rats was raised by steel wire bonding in order to induce occlusal trauma. The destruction of the periodontal ligament was observed and the production of osteopontin and RANKL by periodontal ligament cells was detected via immunohistochemistry. RESULTS: Our model produced wide-ranging destruction of the periodontal ligament. From day 3 to day 7, prominent compression of the periodontal ligament and osteoclast migration were observed at the apical interradicular septum. Osteopontin was detected in some osteoclasts, surrounding fibroblasts, and osteoblasts adjacent to the compression area. RANKL was observed from day 1 to day 7 around the osteoblasts and osteoclasts. CONCLUSIONS: Our model was useful for the detailed investigation of periodontal ligament breakdown during excessive occlusal loading. Although intracellular osteopontin was produced in osteoclasts with intermittent occlusal loading, the role of this protein in the cells was not clear. No correlation between RANKL distribution and osteopontin production in osteoclasts could be found.

Animals↗

An osteonectinlike protein in porcine periodontal ligament and its synthesis by periodontal ligament fibroblasts.

Periodontal ligament, a soft connective tissue that lies between cementum and alveolar bone in the periodontium, has been shown to contain an osteonectinlike protein. The similarity between porcine ligament osteonectin and bovine bone osteonectin was evident from immunochemical studies, from migration characteristics on sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) and from binding studies on hydroxyapatite. Using immunotransfer and immunodot analyses, ligament osteonectin was found to be extractable from tissues with 4 M guanidine-HCl (GuHCl) and 4 M GuHCl - 0.5 M EDTA and to comigrate with authentic bovine osteonectin on SDS-PAGE with a relative mass approximately 38 000. Furthermore, osteonectin from guanidine extracts of ligament was bound to hydroxyapatite in the presence of 4 M GuHCl. Immunofluorescence studies showed the osteonectin to be distributed throughout the extracellular matrix of the ligament and to be present within the ligament fibroblasts in a perinuclear, punctate distribution. Biosynthesis of osteonectin by ligament fibroblasts was studied following pulse-chase labelling with [35S]methionine and immunoprecipitation. The labelled osteonectin in the chased culture medium represented approximately 0.5% of the total labelled proteins secreted. It comigrated on SDS-PAGE with the corresponding labelled protein from pulsed cells and with the protein extracted from the tissue.

Animals↗

Where should the femoral tunnel of a posterior cruciate ligament reconstruction be placed to best restore anteroposterior laxity and ligament forces?

BACKGROUND: Objective results of posterior cruciate ligament reconstruction are often less than satisfactory, with many patients exhibiting excessive posterior laxity. HYPOTHESIS: Changes in the position of the femoral tunnel within the posterior cruciate ligament's femoral footprint will significantly affect anteroposterior laxities and graft forces. STUDY DESIGN: Controlled laboratory study. METHODS: The posterior cruciate ligament's femoral origin was mechanically isolated in 13 fresh-frozen knee specimens, and the bone cap containing the ligament's insertion was attached to a load cell that recorded resultant force during tibial loading tests. Anteroposterior laxity (at +/- 200 N applied force) was also measured. Cast acrylic replicas of the bone cap were fabricated, with tunnels placed in anterolateral, central, and posteromedial regions of the footprint. A graft reconstruction was tested in each tunnel. RESULTS: Mean laxities with the anterolateral tunnel were +0.9 mm to +1.7 mm greater than normal between 0 degrees and 45 degrees of flexion. Mean laxities with the posteromedial tunnel were -2.4 mm to -3.7 mm less than normal between 10 degrees and 45 degrees of flexion. Mean laxities with the central tunnel were not significantly different from intact knee values, except at 0 degrees (0.9 mm greater). Mean graft forces with the anterolateral tunnel were normal for most modes of loading, whereas there were significant increases in graft forces with the posteromedial and central tunnels. CONCLUSION: The anterolateral tunnel reproduced normal posterior cruciate ligament force profiles but produced a knee that was more lax than normal between 0 degrees and 45 degrees of flexion. The central tunnel best matched intact knee laxities, but graft forces were higher than posterior cruciate ligament forces between 0 degrees and 45 degrees of flexion. The posteromedial tunnel overconstrained anteroposterior laxity approximately 2 to 4 mm between 0 degrees and 45 degrees of flexion and generated higher graft forces in the same flexion range. CLINICAL RELEVANCE: This study suggests that a posteromedial tunnel should not be used for single-bundle posterior cruciate ligament reconstruction.

Adult↗

Rupture of the posterior tibial tendon. Evaluation of injury of the spring ligament and clinical assessment of tendon transfer and ligament repair.

Eighteen of twenty-two patients who were having a tendon transfer to treat rupture of the posterior tibial tendon had evidence of injury to the spring ligament. The injury consisted of a longitudinal tear in the ligament in seven patients, a lax ligament without a gross tear in seven, and a complete rupture of the ligament in four. The ruptured posterior tibial tendon was treated with transfer of the flexor digitorum longus in twenty of the twenty-two patients. A variety of methods were used to repair the ligament. It is essential to determine the status of the spring ligament when patients are managed for rupture of the posterior tibial tendon. Patients who have a torn or lax spring ligament in addition to the ruptured posterior tibial tendon may have more severe abnormalities of the hindfoot than those who have only a ruptured tendon.

Adult↗

Lack of effect of a knee ligament injury prevention program on the incidence of noncontact anterior cruciate ligament injury.

BACKGROUND: Studies have suggested that exercise programs can reduce the incidence of noncontact injuries of the anterior cruciate ligament in female athletes. We conducted a two-year prospective study to assess the effects of a knee ligament injury prevention exercise program on the incidence of noncontact anterior cruciate ligament injuries in high-school female athletes. METHODS: A prospective cohort design was used to study high-school female athletes (playing soccer, basketball, and volleyball) from fifteen schools (112 teams) for two consecutive seasons. The schools were divided into treatment and control groups. The treatment group participated in a plyometric-based exercise program twice a week throughout the season. Practice and game exposures and compliance with the exercise program were recorded on a weekly basis. Suspected noncontact anterior cruciate ligament injuries were confirmed on the basis of the history as well as at the time of surgery and/or with magnetic resonance imaging. RESULTS: A total of 1439 athletes (862 in the control group and 577 in the treatment group) were monitored. There were six confirmed noncontact anterior cruciate ligament injuries: three in the treatment group, and three in the control group. The incidence of noncontact anterior cruciate ligament injuries per 1000 exposures was 0.167 in the treatment group and 0.078 in the control group, yielding an odds ratio of 2.05, which was not significant (p > 0.05). CONCLUSIONS: Our results suggest that a twenty-minute plyometric-based exercise program that focuses on the mechanics of landing from a jump and deceleration when running performed twice a week throughout the season will not reduce the rate of noncontact anterior cruciate ligament injuries in high-school female athletes.

Adolescent↗

Healing of the medial collateral ligament in rats. The effects of repair, motion, and secondary stabilizing ligaments.

The effects of repair, motion, and the integrity of the secondary ligamentous restraints on healing of the medial collateral ligament were studied in a rat model. Healing was assessed by measuring ligamentous laxity and tensile strength. All healing ligaments were weaker and more lax than their controls. Repair did not have a statistically significant effect on the laxity or the strength of the medial collateral ligament. Allowing active motion had a statistically significant beneficial effect on the strength of the medial collateral ligament. Stability was adversely affected by active motion if the secondary restraints had been transected; however, when the secondary ligamentous restraints were intact, active motion was beneficial and immobilization was harmful.

Animals↗

Fibroblasts of spinal ligaments pathologically differentiate into chondrocytes induced by recombinant human bone morphogenetic protein-2: morphological examinations for ossification of spinal ligaments.

To elucidate the process of ossification in spinal ligaments, an aqueous solution containing recombinant human bone morphogenetic protein (BMP)-2 (40 micrograms/100 microL) was injected into murine ligamenta flava, and the ossification process was analyzed morphologically. In the control group, the solution administered lacked the protein; these flattened ligamentous fibroblasts possessing BMP receptors type IA and type II existed among type I collagen bundles. In the week immediately following the injection of BMP-2, ligamentous fibroblasts began to proliferate, differentiating into alkaline phosphatase-positive chondrocytes surrounded by an extracellular matrix composed of type I and II collagen. By the second week, differentiated chondrocytes of various stages were observed in type II collagen-rich matrix. These chondrocytes showed an abundance of BMP receptors type IA and II. The pathologically induced cartilage was resorbed by chondroclasts, permitting migration of blood vessels and osteogenic cells, as well as providing a site for endochondral ossification. By the third week, BMP-induced ossification had compressed the spinal cord, and by the sixth week, the ligamentous tissue had been almost completely replaced by bone. Ligamentous fibroblasts appeared to possess BMP receptors, as well as the potentiality to differentiate into chondrocytes. BMP receptors were upregulated during chondrification of ligamentous fibroblasts induced by exogenous BMP-2, suggesting that BMPs may play an important role in ossification of spinal ligaments.

Acid Phosphatase↗

[Rupture of the patellar ligament--a late complication after removal of a bone-tendon-bone transplant as cruciate ligament replacement].

Ruptures of the patellar ligament have been observed in surgery for complete substitution of the knee joint and with application of the operation method according to Roux and Goldwilde; ruptures of this ligament after removal of a graft cruciate ligament substitution have been described very rarely. Since 1990 we have been practicing the method of autologous substitution of the cruciate ligament by using material from the median part of the patellar ligament. In one patient treated by this method who had displayed no complications during 10 months after the operation a new adequate trauma resulted in rupture of the patellar ligament at its tibial insertion. As far as we can assess on the basis of available technical literature, such injury might be due to problems of paraligamentary blood supply, partial or complete resection of the infrapatellar fatty tissue additionally contributing to lasting vascular damage.

Adult↗

Uni-axial cyclic stretch induces Cbfa1 expression in spinal ligament cells derived from patients with ossification of the posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic bone formation in the spinal ligaments. Mechanical stress, which acts on the posterior ligaments, is thought to be an important factor in the progression of OPLL. To clarify this mechanism, we investigated the effects of in vitro cyclic stretch (120% peak to peak, at 0.5 Hz) on cultured spinal ligament cells derived from OPLL (OPLL cells) and non-OPLL (non-OPLL cells) patients. The mRNA expressions of Cbfa1 (an osteoblast-specific transcription factor), type I collagen, alkaline phosphatase (ALP), osteocalcin and integrin beta1 (a mechanotransducer) were increased by cyclic stretch in OPLL cells, whereas no change was observed in non-OPLL cells. The effects of cyclic stretch on the spinal ligament tissues derived from OPLL and non-OPLL patients were also analyzed by immunohistochemistry using an antibody against Cbfa1. The expression of Cbfa1 was increased by cyclic stretch at the center of the spinal ligament tissues of OPLL patients, whereas no change was observed in the tissues of non-OPLL patients. Furthermore, U0126, a specific inhibitor of MAPK kinase (MEK), suppressed the stretch-induced mRNA expressions of Cbfa1, ALP and type I collagen in OPLL cells. These results suggest that in OPLL cells, mechanical stress is converted by integrin beta1 into intracellular signaling and that Cbfa1 is activated through the MAP kinase pathway. Therefore, we propose that mechanical stress plays a key role in the progression of OPLL through an increase in Cbfa1 expression.

Aged↗

Anterior cruciate ligament reconstruction with a multistrand hamstring graft fixed with a Ligament Tension Screw: a new device that can be used to readjust graft tension after fixation.

We developed a new fixation device for reconstruction of the anterior cruciate ligament with a multistrand hamstring graft. This device allows the graft tension to be readjusted after fixation. This device, called a Ligament Tension Screw, consists of three parts, a screw, a washer, and a post. To create the graft, the tendons were formed into a loop. The device was hung from one end of the loop of the graft and a Kennedy-ligament augmentation device (LAD) artificial ligament was hung at the other end. The Kennedy-LAD artificial ligament was used extraarticularly for fixation at the tibia with double staples. Graft tension was increased by turning the screw, which pulls on the post suspending the graft. Fifty-two patients were evaluated after a minimum 2-year follow-up. The evaluation included physical examination, stability measurement with a KT2000 arthrometer, a Cybex muscle strength measurement, a functional test, and scoring of the knee according to the International Knee Documentation Committee (IKDC). Pivot test was negative in 47 patients (91%), but glide occurred in 5 patients (9%). No patient had a "clunk" or markedly poor result on the pivot test. All patients recovered full extension. Seven patients lost full flexion, but the loss of flexion was less than 5 degree in all seven. The KT 2000 arthrometer measurement with 133 N anterior drawer force indicated that 46 patients (88%) had less than 3-mm side-to-side difference. The mean muscle strength of the quadriceps and hamstrings was 91% and 94%, respectively, compared with the findings in the contralateral limb. The functional test showed a one-leg hop distance equal to 94% of that the opposite side. According to the final IKDC evaluation, 48 patients were graded as normal or nearly normal, and 4 patients as abnormal; none was severely abnormal. This study demonstrated satisfactory results for the reconstruction with a multistrand hamstring graft fixed with the new Ligament Tension Screw.

Adolescent↗

Comparative animal study of three ligament prostheses for the replacement of the anterior cruciate and medial collateral ligament.

Three different ligament prostheses (Leeds-Keio, Gore-Tex and a prototype of Aramid) were implanted in sheep knee joints replacing the anterior cruciate ligament and the medial collateral ligament. After 1 yr the knees were explanted and their biomechanical properties were assessed by a drawer test and tensile tests of the implants. Additionally the ligament replacements, the synovial membrane and the lymph nodes were inspected histologically. For each type of prosthesis partial or total ruptures occurred. None of the operated joints regained normal stability and stiffness. Anterior knee stability was best for the Gore-Tex treated group and worst for those joints that received a Leeds-Keio implant. The stiffness and rupture strength were highest for the Gore-Tex prostheses. Histologically the strongest intra-articular inflammatory response was observed in the Gore-Tex treated joints. Inside the drill tunnels the severest foreign body reaction was found for the Aramid prostheses. Gore-Tex fibres often showed good bony integration. Wear particles formed from all prostheses and caused small granulomas and mild synovities. The results suggest that none of the tested materials represent an ideal solution for ligament replacement. Relatively good stability does not guarantee good biocompatibility and vice versa. This suggests that ligament prostheses should be applied only in salvage cases.

Animals↗