Evaluation of the accuracy and intra- and interobserver reliability of three manual laxity tests for canine cranial cruciate ligament rupture-An ex vivo kinetic and kinematic study

OBJECTIVES

To investigate the accuracy and intra- and interobserver reliability of the cranial drawer test (CD), tibial compression test (TCT), and the new tibial pivot compression test (TPCT) in an experimental setting resembling acute cranial cruciate ligament rupture (CCLR) and to elucidate the ability to subjectively estimate cranial tibial translation (CTT) during testing.

STUDY DESIGN

Experimental ex vivo study.

SAMPLE POPULATION

Ten cadaveric hindlimbs of large dogs.

METHODS

Kinetic and 3D-kinematic data was collected while three observers performed the tests on each specimen with intact (INTACT) and transected cranial cruciate ligament (CCLD) and compared using three-way repeated-measures ANOVA. Subjectively estimated CTT (SCTT), obtained during a separate round of testing, was compared to kinematic data by Pearson correlation.

RESULTS

CTT was significantly higher for CCLD than for INTACT for all tests, resulting in 100% sensitivity and specificity. TPCT induced the highest CTT and internal rotation. Intra- and interobserver agreement of translation was excellent. For rotation and kinetics, agreement was more variable. SCTT strongly correlated with the objectively measured values.

CONCLUSION

The CD, TCT and the new TPCT were all accurate and reliable. The high translations and rotations during TPCT are promising, encouraging further development of this test. SCTT was reliable in our experimental setting.

CLINICAL SIGNIFICANCE

Veterinary manual laxity tests are accurate and reliable in acute CCLR. The TPCT might have potential for the assessment of subtle and rotational canine stifle instabilities. The high reliability of SCTT implies that grading schemes for stifle laxity, similar to human medicine, could be developed.

Validation of a novel 3D printed positioning device and dynamic radiographic technique to quantify rotational laxity of the stifle in dogs

Cranial cruciate ligament deficiency (CCLD) results in internal rotational instability of the stifle (RLS). By contrast, tibial torsion (TT) is an anatomical feature of the tibia along its longitudinal axis. The objective of this study was to validate a dynamic radiographic technique to measure internal rotational laxity of the stifle and differentiate it from TT. Models included transection of the CCL for RLS and an osteotomy for TT. One limb within eight pairs of canine cadaveric hind limbs was randomly assigned to CCLD. The contralateral limb underwent TT, followed by CCLD. Neutral and stress radiographs were taken with the limb in a custom rotating 3-D printed positioning device before and after each modification. The position of the calcaneus on neutral views and the magnitude of its displacement under standardized torque were compared within limbs and between groups. Transection of the CCL increased the magnitude of displacement of the calcaneus by 1.6 mm (0.3-3.1 mm, p < 0.05) within limbs. The lateral calcaneal displacement (dS-dN) tended to be greater when CCLD limbs were compared to limbs with intact CCL. A magnitude of calcaneal displacement of 3.45 mm differentiated limbs with RLS from intact limbs with 87.5% sensitivity and 68.7% specificity. The calcaneus was displaced further laterally by about 3 mm on neutral radiographs (dN) when limbs with experimental TT were compared to those without TT (p < 0.05). A calcaneus located at least 3.25 mm from the sulcus differentiated limbs with TT from intact limbs with 87.5% sensitivity and 87.5% specificity. The technique reported here allowed detection of RLS, especially within limbs. A calcaneus located at least 3.25 mm on neutral radiographs of large dogs should prompt a presumptive diagnosis of TT.

In vivo three-dimensional isometry analysis of suture attachment sites for extracapsular suture stabilization of the canine stifle

BACKGROUND

The study aimed to perform isometry analysis of a selection of suture attachment points for extracapsular stabilization with three-dimensional (3D) measurements and normal gait kinematics of the stifle joint.

METHODS

Thirteen client-owned dogs were recruited. Fluoroscopic images of the stifle during treadmill walking and computed tomography of the same joint were acquired. Stifle kinematics were reconstructed using 3D model-based fluoroscopic analysis. Variability of the distance between the femoral and tibial attachment sites across gait cycles was evaluated. The maximum length variation (MLV) and maximum length percent variation (MLPV) were quantified and used to determine the level of isometry of the attachment site combinations.

RESULTS

A selection of combinations with lower mean MLV (<2.5 mm) or MLPV (<8%) was identified from 315 combinations, and all the combinations involved femoral attachment sites near the distal pole of the lateral fabella. The combinations also involving tibial attachment sites near the proximal tibial crest showed improved isometry, with an MLPV < 6%.

CONCLUSION

Combinations using attachment sites around the distal pole of the lateral fabella and proximal tibial crest or caudal to the long digit extensor groove appeared to have improved isometry.

Biomechanical Effects of Tibial Plateau Levelling Osteotomy on Joint Instability in Normal Canine Stifles: An In Vitro Study

OBJECTIVE

 The aim of the study was to determine the changes in biomechanical characteristics following tibial plateau levelling osteotomy (TPLO) using simulated manual tests.

STUDY DESIGN

 Twenty-one stifles from healthy Beagle dogs that had undergone TPLO or had not (control) were first tested in the intact form, and then the cranial cruciate ligament (CrCL) was transected in each to provide four test situations: control-intact, control-CrCL-transected, TPLO-intact and TPLO-CrCL-transected. The stifles were then analysed using a robotic joint biomechanical testing system. The craniocaudal drawer, axial rotation and proximal compression tests were applied.

RESULTS

 The craniocaudal displacement during the drawer test was not significantly different between the control-intact and TPLO-intact. However, the displacement was significantly greater in the TPLO-CrCL-transected than in the control-intact. In the axial rotation test, the internal-external (IE) rotation was significantly greater in the TPLO-intact than in the control-intact. Similarly, the IE rotation was significantly greater in the TPLO-CrCL-transected than in the control-CrCL-transected. In the proximal compression test, craniocaudal displacement was not significantly different among the control-intact, TPLO-intact and TPLO-CrCL-transected.

CONCLUSION

 These findings suggest that TPLO influences the tension of the collateral ligaments and might generate laxity of the tibiofemoral joint. Instability after the osteotomy might be associated with the progression of osteoarthritis.

Prospective clinical assessment of tibial tuberosity advancement for the treatment of cranial cruciate ligament rupture in dogs

PURPOSE

To evaluate clinically dogs that underwent tibial tuberosity advancement (TTA) six months previously.

METHODS

Dogs of various breeds, gender, weight, and age that had CCL rupture and underwent TTA for treatment were included in this study. Parapatellar arthrotomy was performed in all patients to assess the joint for a ruptured ligament and meniscal injury before the TTA. The appropriate cage for the TTA was chosen with planning surgery. The surgical procedure was performed according to the literature, using a modified Maquet technique. Six months after surgery, lameness during walking; muscular atrophy; crepitation, cranial drawer and tibial compression tests and quality of life based on owner's evaluation were assessed.

RESULTS

Postoperative complications were observed in only one knee (4.76%), with a surgical site seroma. The mean lameness score at walking was 0.29 (± 0.64). The mean score regarding muscular atrophy was 0.95 (± 1.56). The mean score of the cranial drawer test, in a range from 0 to 5, was 1.52 (± 1.54). The owners rated the dog's quality of life as excellent in 44%, good in 30%, and moderate in 17%.

CONCLUSION

This clinical study supports the affirmation that patients who undergo TTA for treatment of CCL rupture have an acceptable response.