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At least 1,585 records · Page 88Linked to original sources
PubMed2004

Tibiofemoral kinematics following successful anterior cruciate ligament reconstruction using dynamic multiple resonance imaging.

BACKGROUND: The aim of anterior cruciate ligament reconstruction is to reduce excess joint laxity, hoping to restore normal tibiofemoral kinematics and therefore improve joint stability. It remains unclear if successful ACL reconstruction restores normal tibiofemoral kinematics and whether it is this that is associated with a good result. STUDY: Case series. PURPOSE: To assess the kinematics of the anterior cruciate ligament-reconstructed knee using open-access MRI. METHODS: Tibiofemoral motion was assessed using open-access MRI, weightbearing through the arc of flexion from 0 degrees to 90 degrees in 10 patients with isolated reconstruction of the anterior cruciate ligament (hamstring autograft) in one knee and a normal contralateral knee. Midmedial and midlateral sagittal images were analyzed in all positions of flexion in both knees to assess the tibiofemoral relationship. Sagittal laxity was also assessed by performing the Lachman test while the knees were scanned dynamically using open-access MRI. RESULTS: The amount of excursion between the tibial and femoral joint surfaces was similar between the normal and reconstructed knees, but the relationship of tibia to femur was always different for each position of knee flexion assessed-the lateral tibia being about 5 mm more anterior in the anterior cruciate ligament-reconstructed knees. This anterior tibial position is statistically significantly different at 0 degrees (P <.0006), 20 degrees (P =.0004), 45 degrees (P =.002), and 90 degrees of flexion (P <.006). Anteroposterior laxity was similar between normal and anterior cruciate ligament-reconstructed knees. CONCLUSION: Anterior cruciate ligament reconstruction reduces sagittal laxity to within normal limits but does not restore normal tibiofemoral kinematics despite a successful outcome.

Adult↗
PubMed2004

Abnormal rotational knee motion during running after anterior cruciate ligament reconstruction.

BACKGROUND: The effectiveness of anterior cruciate ligament reconstruction for restoring normal knee kinematics is largely unknown, particularly during sports movements generating large, rapidly applied forces. HYPOTHESIS: Under dynamic in vivo loading, significant differences in 3-dimensional kinematics exist between anterior cruciate ligament-reconstructed knees and the contralateral, uninjured knees. STUDY DESIGN: Prospective, in vivo laboratory study. METHODS: Kinematics of anterior cruciate ligament-reconstructed and contralateral (uninjured) knees were evaluated for 6 subjects during downhill running 4 to 12 months after anterior cruciate ligament reconstruction, using a 250 frame/s stereoradiographic system. Anatomical reference axes were determined from computed tomography scans. Kinematic differences between the uninjured and reconstructed limbs were evaluated with a repeated-measures analysis of variance. RESULTS: Anterior tibial translation was similar for the reconstructed and uninjured limbs. However, reconstructed knees were more externally rotated on average by 3.8 +/- 2.3 degrees across all subjects and time points (P =.0011). Reconstructed knees were also more adducted, by an average of 2.8 +/- 1.6 degrees (P =.0091). Although differences were small, they were consistent in all subjects. CONCLUSIONS: Anterior cruciate ligament reconstruction failed to restore normal rotational knee kinematics during dynamic loading. CLINICAL RELEVANCE: Although further study is required, these abnormal motions may contribute to long-term joint degeneration associated with anterior cruciate ligament injury/reconstruction.

Adolescent↗
PubMedDate not supplied

Isokinetic evaluation of internal/external tibial rotation strength after the use of hamstring tendons for anterior cruciate ligament reconstruction.

BACKGROUND: Evaluation of the knee after an anterior cruciate ligament reconstruction with the use of the semitendinosus and gracilis (hamstring) autografts has primarily focused on flexion and extension strength. The semitendinosus and gracilis muscles contribute to internal tibial rotation, and it has been suggested that harvest of these tendons for the purpose of an anterior cruciate ligament reconstruction contributes to internal tibial rotation weakness. HYPOTHESIS: Internal tibial rotation strength may be affected by the semitendinosus and gracilis harvest after anterior cruciate ligament reconstruction. STUDY DESIGN: Prospective evaluation of internal and external tibial rotation strength. METHODS: Inclusion criteria for subjects (N = 30): unilateral anterior cruciate ligament reconstruction at least 2 years previously, a stable anterior cruciate ligament (<5-mm side-to-side difference) at time of testing confirmed by surgeon and KT-1000 arthrometer, no history of knee problems after initial knee reconstruction, a normal contralateral knee, and the ability to comply with the testing protocol. In an attempt to minimize unwanted subtalar joint motion, subjects were immobilized using an ankle brace and tested at angular velocities of 60 degrees /s, 120 degrees /s, and 180 degrees /s at a knee flexion angle of 90 degrees . RESULTS: The mean peak torque measurements for internal rotation strength of the operative limb (60 degrees /s, 17.4 +/- 4.5 ft-lb; 120 degrees /s, 13.9 +/- 3.3 ft-lb; 180 degrees /s, 11.6 +/- 3.0 ft-lb) were statistically different compared to the nonoperated limb (60 degrees /s, 20.5 +/- 4.7 ft-lb; 120 degrees /s, 15.9 +/- 3.8 ft-lb; 180 degrees /s, 13.4 +/- 3.8 ft-lb) at 60 degrees /s (P = .012), 120 degrees /s (P = .036), and 180 degrees /s (P = .045). The nonoperative limb demonstrated greater strength at all speeds. The mean torque measurements for external rotation were statistically similar when compared to the nonoperated limb at all angular velocities. CONCLUSIONS: We have shown through our study that patients who undergo surgical intervention to repair a torn anterior cruciate ligament with the use of autogenous hamstring tendons demonstrate with weaker internal tibial rotation postoperatively at 2 years when compared to the contralateral limb.

Adult↗
PubMed2004

The effect of posterior knee capsulotomy on posterior tibial translation during posterior cruciate ligament tibial inlay reconstruction.

PURPOSE: To measure the biomechanical effect of the surgical capsulotomy made during a posterior cruciate ligament reconstruction using the tibial inlay technique. HYPOTHESIS: The posterior capsule contributes to posterior tibial stability. STUDY DESIGN: Controlled laboratory experiment. METHODS: Six knee specimens were tested on a robotic testing system from 0 degrees to 120 degrees of flexion with the posterior cruciate ligament intact and resected and with a posterior capsulotomy identical to that performed during tibial inlay reconstruction (sham surgery). A longitudinal incision with medial and lateral soft tissue stripping sufficient to mount an inlay bone block and pass an Achilles tendon graft into the knee was made in the oblique popliteal ligament, muscle belly of the popliteus, and posterior capsule. The posterior tibial translation was measured under a posterior tibial load of 130 N at multiple flexion angles. RESULTS: Capsulotomy increased the posterior laxity compared with the posterior cruciate ligament-resected knee at every flexion angle. An additional 0.97 +/- 0.48 mm, 0.65 +/- 0.47 mm, 0.56 +/- 0.33 mm, 0.48 +/- 0.38 mm, and 0.94 +/- 0.60 mm of posterior laxity was recorded at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion, respectively. These values were all statistically significant (P < .001). CONCLUSIONS: A posterior capsulotomy alone, without associated posteromedial or posterolateral disruption, produces additional posterior tibial translation in vitro compared with posterior cruciate ligament-deficient knee with intact capsule. CLINICAL RELEVANCE: Damage to the posterior capsule may contribute to the residual posterior laxity noted clinically after posterior cruciate ligament reconstruction.

Achilles Tendon↗
PubMed2005

Arthroscopic cartilage indentation and cartilage lesions of anterior cruciate ligament-deficient knees.

BACKGROUND: The anterior cruciate ligament-deficient knee is prone to osteoarthritis and meniscus lesions. Very little, however, is known about the biomechanical properties of articular cartilage in anterior cruciate ligament-deficient knees. PURPOSE: To evaluate biomechanical and macroscopical cartilage changes in the knee joint with respect to the time after anterior cruciate ligament rupture. HYPOTHESIS: Chronic anterior cruciate ligament deficiency induces cartilage softening. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Cartilage stiffness of 50 patients undergoing anterior cruciate ligament reconstructive surgery because of symptomatic knee instability after chronic anterior cruciate ligament rupture was measured with an arthroscopic indenter device, and the number and size of cartilage lesions were evaluated. RESULTS: The cartilage stiffness did not correlate with time from trauma to surgery (r = 0.002, P = .99), but the number of cartilage lesions in the knee increased when the time from the initial trauma to reconstructive surgery increased (r = 0.356, P = .011). Indentation values measured on healthy-looking cartilage on damaged joint surfaces were lower than the values measured on healthy joint surfaces (P < .01 on lateral femoral condyle and on tibial plateaus). CONCLUSIONS: The number of cartilage lesions increases with increased time after initial trauma. The arthroscopic indenter device is able to detect cartilage softening as the early mechanical sign of degradation not yet visible to the eye.

Adolescent↗
PubMedDate not supplied

Collagen fibril organization in the patellar tendon autograft after posterior cruciate ligament reconstruction. A quantitative evaluation in a sheep model.

We replaced the posterior cruciate ligament in 30 skeletally mature sheep with a patellar tendon autograft using the central third of the ipsilateral patellar tendon. The healing autograft was compared with the contralateral posterior cruciate ligament and the patellar tendons and posterior cruciate ligaments of nonoperated animals. The collagen fibril diameters were analyzed using transmission electron photomicrographs of fibril cross sections taken at six periods during the 2 years after surgery. The patellar tendon and posterior cruciate ligament were characterized by a broad, nongaussian distribution of collagen fibril diameters. The autografts shifted to a unimodal distribution by an increase of small-diameter collagen fibrils. The frequency of small-diameter fibrils measuring up to 100 nm was 99% after 2 years. At that time, these small-diameter fibrils represented 91.6% of the area covered by collagen fibrils. The mean diameter of the collagen fibrils in the autografts significantly decreased to 45% of the controls at Week 26 and remained at this level until the end of this study. The percentage of area covered by collagen fibrils per 1 micron 2 was 78% of the controls 2 years post-operatively. This study suggests that the patellar tendon autograft could not reproduce the collagen fibril organization of the posterior cruciate ligament. This may be a biologic factor responsible for inconsistent results in posterior cruciate ligament replacement.

Actin Cytoskeleton↗
PubMedDate not supplied

Evidence of reinnervation of free patellar tendon autograft used for anterior cruciate ligament reconstruction.

We studied six adult male dogs to determine whether free patellar tendon grafts show evidence of reinnervation when used for anterior cruciate ligament reconstruction. Histologic return of neural elements and return of a somatosensory-evoked potential defined evidence of reinnervation. Before removal, the native anterior cruciate ligament was electrically stimulated with a bipolar electrode and a somatosensory-evoked potential was recorded from a scalp electrode. The ligament was excised and reconstructed using an autogenous patellar tendon graft. Somatosensory-evoked potential was attempted immediately after reconstruction. Histology for nerve endings was performed on the native ligaments. Each animal underwent repeat arthrotomy 6 months later. The grafts were isolated and somatosensory-evoked potentials were attempted. An evoked potential was seen in all six dogs before reconstruction. No graft demonstrated a somatosensory-evoked potential acutely; however, 6 months postoperatively, the somatosensory-evoked potential returned in two cases. Histology of native ligaments showed that 25% of the 100 sections evaluated contained neural elements. Of the receptors present, 89% were mechanoreceptors and 11% were free nerve endings. Histologic examination of the graft tissue 6 months postoperatively revealed that all six grafts also contained neural elements. Mechanoreceptors and free nerve endings were present in approximately equal numbers in the grafts. The results of histology and somatosensory-evoked potential demonstrate that in at least some cases, free patellar tendon grafts show evidence of reinnervation when used for anterior cruciate ligament reconstruction.

Animals↗
PubMedDate not supplied

The effects of grade III posterolateral knee complex injuries on anterior cruciate ligament graft force. A biomechanical analysis.

To determine if untreated grade III injuries of the posterolateral structures contribute to increased force on an anterior cruciate ligament graft, we measured the force in the graft in cadaveric knees during joint loading after reconstruction with otherwise intact structures and in the same reconstructed knees after selected cutting of specific posterolateral knee structures. Tests were first performed on the knee with the posterolateral structures intact and then after sequential sectioning of the fibular collateral ligament, popliteofibular ligament, and popliteus tendon. The graft force was significantly higher after fibular collateral ligament transection during varus loading at both 0 degree and 30 degrees of knee flexion than it was for the same loading of the joint with intact posterolateral structures. In addition, coupled loading of varus and internal rotation moments at 0 degree and 30 degrees of flexion further increased graft force beyond that with varus force alone. The increase in graft force remained significant with additional sequential cutting of the popliteofibular ligament and popliteus tendon. We believe this study supports the clinical observation that untreated grade III posterolateral structure injuries contribute to anterior cruciate ligament graft failure by allowing higher forces to stress the graft.

Anterior Cruciate Ligament↗
PubMedDate not supplied

Current trends in anterior cruciate ligament reconstruction. Part 1: Biology and biomechanics of reconstruction.

With today's increasing emphasis on sporting activities, the incidence of anterior cruciate ligament injuries has also increased. Epidemiologic studies estimate that the prevalence of anterior cruciate ligament injuries is about 1 per 3000 Americans. Management of these injuries has evolved from nonoperative treatment to extracapsular augmentation and primary ligament repair to anterior cruciate ligament reconstruction. Treatment of these injuries has significantly improved over the last few decades with the application of knowledge gained from both basic science and clinical research. This article is composed of two parts. The first part reviews the biology and biomechanics of the injured anterior cruciate ligament and the basic science of reconstruction. In the second part, to be published later, current operative concepts of reconstruction, as well as clinical correlations, are reviewed. Summarizing the latest information on basic scientific as well as clinical studies regarding the anterior cruciate ligament, this article intends to demonstrate the correlation between the application of basic science knowledge and improvement of clinical outcomes.

Anterior Cruciate Ligament↗
PubMed2005

Muscle, ligament, and joint-contact forces at the knee during walking.

PURPOSE: In vivo measurement of the forces and strains in human tissues is currently impracticable. Computer modeling and simulation allows estimates of these quantities to be obtained noninvasively. This paper reviews our recent work on muscle, ligament, and joint loading at the knee during gait. METHODS: Muscle and ground-reaction forces obtained from a sophisticated computer simulation of walking were input into a detailed model of the lower limb to obtain ligament and joint-contact loading at the knee for one full cycle of gait. RESULTS: Peak anterior cruciate ligament (ACL) force occurred in early stance and was mainly determined by the anterior pull of the patellar tendon on the tibia. The medial collateral ligament was the primary restraint to anterior tibial translation (ATT) in the ACL-deficient knee. ATT in the ACL-deficient knee can be reduced to the level calculated for the intact knee by increasing hamstrings muscle force. Reducing quadriceps force was insufficient to restore ATT to the level calculated for the intact knee. For both normal and ACL-deficient walking, the resultant force acting between the femur and tibia remained mainly on the medial side of the knee. The knee adductor moment was resisted by a combination of muscle and ligament forces. CONCLUSION: Knee-ligament loading during the stance phase of gait is explained by the pattern of anterior shear force applied to the leg. The distribution of force at the tibiofemoral joint is determined by the variation in the external adductor moment applied at the knee. The forces acting at the tibiofemoral and patellofemoral joints are similar during normal and ACL-deficient gait. Hamstrings facilitation is more effective than quadriceps avoidance in reducing ATT during ACL-deficient gait.

Anterior Cruciate Ligament↗
PubMed1997

A follow-up arthroscopy after anterior cruciate ligament reconstruction using the patellar tendon augmented by woven polyester.

Follow-up arthroscopy was performed on 9% patients who had undergone anterior cruciate ligament (ACL) reconstruction with patellar tendon augmented by woven polyester. The interval between surgery and arthroscopy ranged from 6 to 26 months, with a mean of 13.1 months. The patients were classified into 4 grades according to the arthroscopical findings as follows: grade 1, ligamentous tissue ruptured or not observed; grade II, loose and thin ligamentous tissue observed; grade III, thick and taut ligamentous tissue observed, but some ligamentous strands exposed from the synovial tissue: grade IV, thick and taut ligamentous tissue with a synovial tissue observed, as in normal ACL. Based on the arthroscopical findings, 4 of the 92 patients were rated as grade I, 11 as grade II, 24 as grade III, and 53 as grade IV. Correlation between the arthroscopical and functional test results indicated that the mean injured-to-uninjured differences of KT-1000 measurements were significantly smaller in the grade IV group than in the grade I and grade II groups (p < 0.05). These results suggest that postoperative anterior knee laxity correlate significantly with arthroscopical results, and is a useful parameter for evaluating ACL reconstruction.

Adolescent↗
PubMedDate not supplied

Strain measurement at the knee ligament insertion sites.

We describe the modification of an existing method of ligament strain measurement at the knee joint in detail. At ten fresh joint specimens we used that technique where strain gauges are attached to the ligamentous insertions and origins. We both improved the preparation of the attachment site and the application of the strain gauges. In a special apparatus the specimens were moved from 0 degree extension to 100 degrees flexion while simulating muscle strength and axial force. Testing was performed at the posterior cruciate ligament with both intact and transsected anterior cruciate ligament. In contrast to other existing techniques it does not affect the motion of the joint or the integrity and the function of the ligaments. Unlike the original description of that method we could register a loading behaviour of the posterior cruciate ligament that is similar to those reported in the literature.

Compliance↗
PubMed1993

The effects of sectioning of the posterior cruciate ligament and the posterolateral complex on the articular contact pressures within the knee.

Articular contact pressures in ten cadaveric knees with intact ligaments were measured with the use of film and a model that simulated non-weight-bearing resistive extension of the knee. The measurements were repeated after sequential sectioning of the posterior cruciate ligament and the posterolateral complex (the posterolateral capsule, the popliteus muscle and tendon, and the lateral collateral ligament). Patellofemoral pressures and quadriceps load were most significantly elevated after combined sectioning of the posterior cruciate ligament and the posterolateral complex. Medial compartment pressure was significantly elevated after sectioning of the posterior cruciate ligament. The results coincided with, and may partially explain, the clinical findings associated with these types of ligamentous injuries.

Aged↗
PubMed1994

The measurement of elongation of anterior cruciate-ligament grafts in vivo.

Many investigators who have studied the mechanical behavior of anterior cruciate-ligament grafts have attributed the increase in anterior translation of the tibia relative to the femur (an increase in the anterior laxity of the knee joint) to the temporal changes in the material behavior (strength and elastic properties) of the graft that occur throughout the process of remodeling. However, with the onset of motion of the joint, it is unclear whether the repeatable mechanical behavior of the graft remains unchanged immediately after fixation, if the fixation slips, or if the length of the graft changes and produces an increase in anterior translation of the tibia relative to the femur. It is also unknown if procedures performed by different surgeons, using similar graft material and similar operative techniques, can produce similar mechanical behavior of the graft, or if the behavior of the graft is similar to that of the normal anterior cruciate ligament. In an effort to address these questions, two surgeons performed a reconstruction of the anterior cruciate ligament on ten patients each (groups 1 and 2) with use of a bone-patellar ligament-bone graft. Immediately after fixation of the graft, a Hall-effect transducer was implanted to measure the changes in the length of the mid-substance of the graft while the knee was moved through twenty cycles of passive flexion-extension. Unlike the length pattern of the normal anterior cruciate ligament, the length pattern of the graft changed during the initial cycles of passive motion of the knee. We defined this phenomenon as the cyclic response of the graft and characterized it by calculation of the changes in the length of the graft at fixed positions of the knee across the multiple cycles of passive motion. In some patients, the length of the graft increased through the initial passive-motion cycles, while in others, it decreased. With the knee nearly extended, the predicted increase in anterior translation of the tibia relative to the femur, resulting from the increase in the length of the graft, was a maximum of 1.0 millimeter. This indicates that increases in anterior translation of the tibia relative to the femur can occur immediately after reconstruction of the anterior cruciate ligament and that changes in the length of the graft occur after fixation at loads that are less than the ultimate failure load of the graft or of the fixation.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed2004

Tibial plateau leveling osteotomy in a llama with a ruptured cranial cruciate ligament.

A 3-year-old 155-kg (342-lb) castrated male llama was examined because of left hind limb lameness of acute onset. A diagnosis of cranial cruciate ligament and medial collateral ligament rupture was made, and tibial plateau leveling osteotomy was recommended. The tibial plateau leveling osteotomy procedure was performed as described for dogs, except that 2 orthopedic plates were used to stabilize the osteotomy because of the size of the llama. The medial collateral ligament was sutured and reinforced with 2 strands of size-2 polypropylene placed in a figure-8 fashion between cancellous bone screws in the femur and tibia. Four days after surgery, failure of the medial collateral ligament repair was evident. Approximately 3.5 years after surgery, the llama was reexamined. The owners reported that the llama had full use of its left hind limb, and only mild lameness (grade 1 of 5) was evident. Results suggest that tibial plateau leveling osteotomy may be applicable in camelids with rupture of the cranial cruciate ligament. However, additional study is needed before tibial plateau leveling osteotomy can be routinely recommended. In particular, additional information is needed on the tibial plateau slope in healthy camelids, the role of the fibula in tibial plateau leveling osteotomy procedures, and the prevalence of cranial cruciate ligament rupture in camelids.

Animals↗
PubMed1994

Ligament tension affects nuclear shape in situ: an in vitro study.

This study was carried out to test the hypothesis that a relationship exists between ligament tension and ligament cell geometry. Rabbit knee joints were positioned at 70 degrees of joint flexion and the medial collateral ligament (MCL) was mechanically isolated and the femur-MCL-tibia complex was stretched or compressed by displacing the crosshead of a materials testing machine: -2.0 mm (relative compression), 0.0 mm (a reproducible no-load starting point), +/-0.7 mm or + 1.4 mm (relative tension). Each MCL complex was then fixed immediately in 10% neutral buffered formalin. Contralateral knees were dissected similarly with MCLs exposed and fixed in situ at 70 degrees of flexion. Subsequent to histological processing, measurements were made of the profiles of fibrocyte nuclei (since previous work has shown that nuclear shape closely approximates fibrocyte shape) that were located in the central portion of each MCL midsubstance using a video-based computerized morphometry system. Results showed that the dimensions of nuclei in the midsubstance of experimental MCLs were significantly longer and thinner at crosshead displacements that corresponded to increased ligament tension. At +1.4 mm of displacement fibrocyte nuclei were approximately 4 microm longer and 1 microm thinner than those fixed at 0.0 mm, an observation supported by a statistically significant increase in the mean maximum-to-minimum-diameter ratio and a significant decrease in mean cell roundness. These results strongly suggest that mechanical load can directly affect ligament fibrocyte geometry in situ. If a similar phenomenon also occurs in vivo, the metabolism of ligament fibrocytes may be influenced considerably by their loading history.

Animals↗
PubMed1995

High intrinsic healing potential of human anterior cruciate ligament. Organ culture experiments.

We studied the intrinsic healing capacity of human semitendinosus tendon specimens, comparing them to human anterior cruciate ligament specimens collected at the time of ligament reconstructions, and using an organ culture model. On the day after cultivation, migration of cells and synthesis of collagen fibers were observed in the ligament group with preserved synovium (PS), the ligament group with resected synovium (RS), and the semitendinosus tendon group (ST). Migrating cells and newly-formed collagen fibers were most prominent in the PS group, followed by the RS, and ST groups. When the area occupied by the migrating cells and newly-formed collagen fibers in the prepared hole was measured, no differences were observed between the groups at week 2. However, differences were noted between the ST and PS or RS groups at weeks 4 and 6. Our findings indicate that the human anterior cruciate ligament possesses a high intrinsic healing capacity. It is also suggested that the synovium plays an important role in enhancing ligament healing capacity.

Adolescent↗
PubMed1999

Radiographic measurement of craniocaudal instability in stifle joints of clinically normal dogs and dogs with injury of a cranial cruciate ligament.

OBJECTIVE: To determine craniocaudal laxity of the stifle joint of dogs when joints were positioned in tibial compression or neutral position. SAMPLE POPULATION: 19 normal stifle joints in 10 clinically normal dogs, 29 stifle joints with varying injury to the cranial cruciate ligament (10 complete ruptures alone, 10 complete ruptures with concomitant damage to the medial meniscus, 6 partial ruptures alone, and 3 partial ruptures with concomitant meniscal tearing), and 19 unaffected contralateral stifle joints in those 29 dogs. PROCEDURE: Relative displacement of bony landmarks was measured on paired lateral radiographs (neutral and tibial compression positions). Two measuring techniques were customized for use in dogs. RESULTS: The first technique failed to distinguish results in normal stifle joints from those in stifle joints with partial deficiency of cranial cruciate ligaments. Significant differences were found for joints with complete rupture, compared with stifle joints in clinically normal dogs. The second technique detected differences between normal stifle joints and injured joints with partial or complete rupture of the cranial cruciate ligament. Significant differences were not detected between joints with partial versus complete rupture. Adjusting data to account for size of dog did not improve results. CONCLUSIONS AND CLINICAL RELEVANCE: A wide range in measurements of laxity was found for stifle joints with intact cranial cruciate ligaments. Differences in degree of damage to the ligament and medial meniscus cannot be deduced from the amount of relative displacement measured on radiographs. Pathologic changes to the cranial cruciate ligament will not necessarily induce detectable changes in laxity of stifle joints in dogs.

Animals↗