Three-dimensional kinematics of the intact and cranial cruciate ligament-deficient stifle of dogs

Effect of center of rotation of angulation-based levelling osteotomy on instantaneous center of rotation ex vivo

Cranial cruciate ligament rupture is a common cause of femorotibial instability in dogs. Despite numerous techniques being described for achieving joint stabilization, no consensus exists on the optimal management strategy. This ex vivo study utilized the path of the instantaneous center of rotation (ICR) to compare normal, pathological and treated joints. Fluoroscopic recordings of seven limbs from a previous study of canine stifle joint stability following center of rotation of angulation-based levelling osteotomy (CBLO) with and without hamstring loading were analyzed using least-squares approximation of the ICR and estimation of percentage gliding (vs. rolling) to determine if alterations in ICR path and gliding caused by CCL transection and following meniscal release could be normalized by CBLO. In intact joints, the ICR path was located mid-condyle, but this shifted significantly proximally and caudally following CCL transection and medial meniscal release (p < 0.007, p < 0.04). Hamstring loading resulted in qualitative and some quantitative improvements in joint movement based on percentage gliding movement analysis. The ICR path after CBLO remained significantly different to the intact location with or without a hamstring load (p < 0.02, p < 0.04), potentially consistent with CBLO aims of mild residual instability. CBLO resulted in percentage gliding characteristics not significantly different to intact joints (p > 0.08). Qualitative improvements in ICR path and percentage gliding quantities and variability suggest that hamstring loading positively influences joint biomechanics and that further investigation of this role ex vivo and clinically is warranted.

Instantaneous center of rotation in the canine femorotibial joint: Ex vivo assessment of a tool to evaluate joint stabilization surgeries

Cranial cruciate ligament rupture is a common cause of femorotibial joint instability in the dog. Numerous techniques including several tibial osteotomies have been described for stabilization, but there is no current consensus on the best method. The instantaneous center of rotation (ICR) can aid investigations of pathological joint movement, but its use is problematic in the femorotibial joint due to combined rotation and translation during flexion and extension. Using fluoroscopic images from an earlier cadaveric study of canine joint stability, an interpolation method was used to create repeatable rotational steps across joint situations, followed by least squares approximation of the ICR. The ICR in intact joints was located mid-condyle but displaced significantly (P < 0.001) proximally following cranial cruciate ligament transection and medial meniscal release. Individual joints appear to respond differently to destabilization. Triple tibial osteotomy partially restored ICR location during early movement from flexion to extension. Joint instability significantly altered the proportions of rolling and gliding movement at the joint surface (P < 0.02), which triple tibial osteotomy partially improved. While triple tibial osteotomy restores joint stability ex vivo and clinically, normal biomechanics of the joint are not restored. The methods described here may prove useful for comparison of osteotomy techniques for stabilization of the cranial cruciate ligament deficient femorotibial joint in dogs.

The effect of joint orientation on passive movement of the dog's stifle

Introduction

The cranial cruciate ligament (CCL) is one of numerous structures which determine the path of the tibia relative to the femur when passively flexing/extending the stifle of the dog. The effect of cutting the CCL on passive motion with the hind limb in different orientations, is unknown. The aim of this study was to describe passive movement of the tibia relative to the femur in dogs, with the hind limb in three different orientations, and with CCL intact and cut.

Methods

Ten cadaveric hind limbs were obtained from dogs weighing between 20 kg and 25 kg and prepared for testing in a custom-built joint testing machine. Each hind limb was tested in three different orientations with data collected, using an electromagnetic tracking system, during 2 cycles of flexion/extension with the CCL intact and cut. Each cycle was initiated with the stifle in full extension (0°) and data was collected at 0°, 20°, 30°, 40°, 45°, and 55° of stifle flexion/extension.

Results

Flexion of the stifle resulted in caudal translation and internal rotation of the tibia relative to the femur, with cranial translation and external rotation occurring during extension along the identical path. Cutting the cranial cruciate ligament did not result in significant differences in translation or rotation when the stifle was orientated to approximated the standing position of a dog.

Discussion

Isometric points at the origin and insertion of the CCL can potentially be identified in CCL deficient stifles using a technique based on passive motion of an intact stifle.

Three-dimensional kinematic evaluation of lateral suture stabilization in an in vitro canine cranial cruciate deficient stifle model

The impact of surgical correction of cranial cruciate ligament rupture (CCLR) on 3D kinematics has not been thoroughly evaluated in dogs. The success of current techniques remains limited, as illustrated by suboptimal weightbearing and progression of osteoarthritis. The inability to restore the stifle's 3D kinematics might be a key element in understanding these suboptimal outcomes. The objective of this study was to evaluate the impact of lateral suture stabilization (LSS) on the 3D kinematics of the canine stifle joint. We hypothesized that LSS would not restore 3D kinematics in our model. Ten cadaveric pelvic limbs collected from large dogs (25-40 kg) were tested using a previously validated apparatus that simulates gait. Three experimental conditions were compared: (a) intact stifle; (b) unstable stifle following cranial cruciate ligament transection (CCLt) and (c) CCLt stabilized by LSS. Three-dimensional kinematics were collected through 5 loading cycles simulating the stance phase of gait and curves were analyzed using a Wilcoxon signed-rank test. LSS restored baseline kinematics for the entire stance phase for cranial and lateromedial translation, flexion, and abduction. It restored distraction over 90% of the stance phase. Internal rotation was limited, but not restored. This in vitro study had limitations, as it used a simplified model of stifle motion and weight-bearing. The results of this study report that LSS can restore physiologic 3D kinematics largely comparable to those of healthy stifles. Suboptimal outcome in patients following CCLR stabilization by LSS may therefore result from causes other than immediate postoperative abnormal 3D kinematics.

Biomechanics of the Canine Elbow Joint

The canine elbow joint is a complex joint, whose musculoskeletal anatomy is well investigated. During the last 30 years kinematic analysis has gained importance in veterinary research and kinematics of the healthy and medial coronoid disease affected canine elbow joint are progressively investigated. Video-kinematographic analysis represents the most commonly used technique and multiple studies have investigated the range of motion, angular velocity, duration of swing and stance phase, stride length and other kinematic parameters, mostly in the sagittal plane only. However, this technique is more error-prone and data gained by video-kinematography represent the kinematics of the whole limb including the soft tissue envelope. A more precise evaluation of the in vivo bone and joint movement can only been achieved using fluoroscopic kinematography. Based on recent studies significant differences in the motion pattern between healthy joints and elbows with medial coronoid disease could be detected. Thereby not only adaptive changes, caused by pain and lameness, could be described, but primary changes in the micromotion of the joint forming bones could be found, which potentially represent new factors in the pathogenesis of medial coronoid disease. This chapter gives a review of current literature on elbow joint kinematics, with particular focus onto pathologic biomechanics in dysplastic canine elbows.

Cranial Cruciate Ligament Rupture in Dogs: Review on Biomechanics, Etiopathogenetic Factors and Rehabilitation

Cranial cruciate ligament (CrCL) rupture is one of the most common orthopaedic conditions in veterinary medicine. CrCL plays a fundamental role in the stability and biomechanics of the femoral-tibio-patellar joint, and its incorrect functionality severely impacts on the quality of life of patients. In dogs, the structural weakening of this joint due to the progressive degeneration of the ligament is the most accredited etiopathogenetic hypothesis in relation to the dog signalment (breed, sex and age) and the stifle joint conformation. In humans, this injury is often traumatic and generally occurs during sporting activities. CrCL rupture can be managed conservatively or surgically, and decisions regarding treatment are due to numerous factors: the patient’s age and health, the degree of stifle instability, and cost. Physiotherapy protocols play an important role in rehabilitation, with similar goals in humans and dogs: pain management, physiological articular range of motion recovery, periarticular and core muscle strengthening, and proprioceptive deficit correction. Physiotherapy, even if often neglected in veterinary medicine, is mandatory for the recovery of the correct functionality of the injured limb and for the return to normal daily and sporting activities.

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.

In vivo three-dimensional knee kinematics in goats with unilateral anterior cruciate ligament transection

Although the goat is an established animal model in anterior cruciate ligament (ACL) research, in vivo kinematics associated with ACL deficiency have not been previously described in this species. Three-dimensional knee kinematics were determined before and after unilateral ACL transection in eight goats. Fluoroscopic imaging of the knees during treadmill walking and force-platform gait analysis during over-ground walking were performed prior to ACL transection, and 2 weeks, 3 months, and 6 months after ACL transection. Transient lameness of the ACL-transected limb was noted in all goats but resolved by 3 months post-ACL transection. Increased extension of 8.7° to 17.0° was noted throughout the gait cycle in both the ACL-transected and the contralateral unaffected knees by 3 months post-ACL transection, in a bilaterally symmetric pattern. Peak anterior tibial translation increased by 3 to 6 mm after ACL transection and persisted over the 6-month study period. No changes in axial rotation or abduction angle were observed after ACL transection. Unilateral ACL deficiency in goats resulted in persistent kinematic alterations, despite the resolution of lameness by 3 months post-ACL transection.

Subsequent meniscal tears following tibial tuberosity advancement and tibial plateau leveling osteotomy in dogs with cranial cruciate ligament deficiency: An in vivo experimental study

OBJECTIVE

To evaluate the short- and mid-term effects of tibial tuberosity advancement (TTA) and tibial plateau leveling osteotomy (TPLO) on subsequent meniscal tears.

STUDY DESIGN

Experimental in vivo study.

ANIMALS

Purpose-bred beagle dogs (n = 15).

METHODS

For each dog, the cranial cruciate ligaments were transected; one limb underwent TTA and the other limb underwent TPLO. Orthopedic and radiographic examinations were performed preoperatively and at 12 and 32 weeks postoperatively. Gross evaluation of the stifle joint was performed after euthanasia at 12 (n = 10) and 32 (n = 5) weeks.

RESULTS

Lameness scores were not different between TTA and TPLO limbs at any time point. Radiographic osteoarthritis scores of TTA stifles (1.33 ± 0.49) were higher than TPLO stifles (0.67 ± 0.49) (p = .002) at 12 weeks postoperatively, but there was no difference between groups at 32 weeks postoperatively. Subsequent medial meniscal tears occurred in 6/10 TTA stifles, and 0/10 TPLO stifles at 12 weeks postoperatively and in 5/5 TTA stifles, and 1/5 TPLO stifles at 32 weeks postoperatively. Subsequent lateral meniscal tears occurred in 4/5 TTA stifles at 32 weeks postoperatively. Medial meniscal total gross pathology score was higher in TTA than TPLO stifles. TTA stifles had more articular cartilage damage when compared with TPLO stifles at 32 weeks postoperatively.

CONCLUSION

In this within-dog experimental comparison, subsequent medial meniscal tears and cartilage injury was more prevalent following TTA when compared to TPLO.

CLINICAL SIGNIFICANCE

In an experimental model, TPLO protects the medial meniscus and articular cartilage better than TTA in stifles with complete cranial cruciate ligament deficiency.

Femorotibial joint kinematics in nine dogs treated with lateral suture stabilization for complete cranial cruciate ligament rupture

OBJECTIVE

To quantify 3-D femorotibial joint kinematics during ambulation in dogs with cranial cruciate ligament (CCL) rupture treated with lateral fabellotibial suture stabilization (LFTS).

ANIMALS

9 adult dogs (body weight, 15 to 35 kg [33 to 77 lb]) with unilateral complete CCL rupture.

PROCEDURES

Digital 3-D bone models of the femur and fabellae and tibia and fibula were created from CT scans. Lateral fluoroscopic images of stifle joints were collected during treadmill walking before surgery and 6 months after LFTS. The LFTS was performed with nylon leader material secured with knots. Gait cycles were analyzed with a 3-D to 2-D image registration process. Femorotibial joint kinematics (craniocaudal translation, internal-external rotation, and flexion and extension angles) were compared among CCL-deficient stifle joints before LFTS, CCL-deficient stifle joints 6 months after LFTS, and unaffected contralateral (control) stifle joints. Owners and veterinarians subjectively assessed lameness by use of a visual analog scale and gait examination, respectively, at each time point.

RESULTS

At midstance phase, medial cranial tibial translation decreased from 9.3 mm before LFTS to 7.6 mm after LFTS but remained increased when compared with control stifle joint values. Following LFTS, axial rotation and stifle joint flexion and extension angles were not significantly different from control stifle joints. On the owner survey, the median walking lameness score improved from 9.3 of 10 before surgery to 0.3 after surgery. On gait examination, median walking lameness score improved from 2 of 4 before surgery to 0 after surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

Stifle joint instability was only slightly mitigated at 6 months following LFTS performed with knotted nylon leader material in medium to large dogs with CCL rupture, despite improvement in lameness.

Titanium-Alloy Anchoring System as a Suitable Method of Extracapsular Repair

Objective: To characterize the effect of a titanium-alloy anchoring system (TAS) on the motion of the cranial cruciate ligament (CrCL) deficient stifle. To compare the motion with the TAS to that of the CrCL-intact and CrCL-deficient stifle.

Study Design: Each canine pelvic limb was mounted in a loading jig under 30% body weight. Motion data was collected using an electromagnetic tracking system at stifle angles of 125°, 135°, and 145° with the CrCL-intact, CrCL-deficient and the TAS applied.

Results: Total translation of the CrCL-deficient stifle following the TAS was reduced, but remained greater than the CrCL-intact stifle at angles of 125°, 135°, and 145°. Internal rotation of the TAS groups was greater than the CrCL-intact group at 145°, but not 125° and 135°. Varus motion of the TAS group was decreased compared to the CrCL-deficient group, but increased compared to the CrCL-intact group at angles of 125°, 135°, and 145°.

Conclusion: Total translation and internal rotation of the CrCL-deficient stifle following the TAS differed from that of the CrCL-intact stifle. However, the TAS reduced total translation and internal rotation of the tibia relative to the femur in the CrCL-deficient stifle to levels that may yield clinically acceptable results.

Center of rotation of angulation-based leveling osteotomy combined with a coplanar cranial closing wedge ostectomy to manage cranial cruciate ligament insufficiency in dogs with excessive tibial plateau angle

OBJECTIVE

To describe outcomes of dogs with excessive tibial plateau angle (eTPA) and cranial cruciate ligament (CrCL) disease treated with center of rotation of angulation-based leveling osteotomy (CBLO) and cranial closing wedge ostectomy (CCWO).

STUDY DESIGN

Retrospective study.

ANIMALS

Twenty-one dogs.

METHODS

Medical records of dogs with CrCL disease and eTPA (>34°) treated with CBLO/CCWO were reviewed. Signalment, body weight, intra-articular structure appearance, TPA (preoperatively, postoperatively, and at osteotomy healing), postoperative function, and complications were recorded.

RESULTS

Twenty-one dogs (28 stifles) with CrCL disease/eTPA underwent CBLO/CCWO. Twenty stifles had complete CrCL tears and eight tears were partial. Mean age and weight of dogs were 4 years (range, 1-9) and 27 kg (range, 4-65), respectively. Medial menisci were normal in 20 stifles, torn in 5, and degenerative in 3. All lateral menisci were normal. The caudal cruciate ligament was normal in 26 stifles and partially torn in 2. Mean TPA was 43° preoperatively, 10° postoperatively, and 10° at final recheck. Grade 4 healing occurred in all osteotomies by 8 weeks postoperatively. Complications included one pin migration, breakage of two proximal screws (1 case), one late-onset caudolateral band CrCL tear, two late-onset meniscal tears, and one surgical site infection. Eighteen dogs returned to full function, and three dogs achieved acceptable function, at a mean of 27 months.

CONCLUSION

Center of rotation of angulation-based leveling osteotomy/CCWO resulted in grade 4 osteotomy healing by 8 weeks, minimal complications, and acceptable to full return to function.

CLINICAL SIGNIFICANCE

Center of rotation of angulation-based leveling osteotomy/CCWO should be considered to treat canine CrCL disease/eTPA.

Review of kinematic analysis in dogs

Objective gait analysis techniques aid investigators in the study of motion. Kinematic gait analysis techniques that objectively quantitate motion are valuable tools used to understand normal and abnormal motion in domestic animals. Recent advances in video technology have made the study of motion more readily accessible. Available systems can document gait in two or three dimensions (2D or 3D, respectively). Knowledge of fundamental gait analysis concepts is critical to generating meaningful data. The objective of this report is to review principles of kinematic data collection and analyses, with a focus on differences between 2D and 3D systems.

Evaluation of cranial tibial translation in dogs: Diagnostic accuracy of radiographic method using a simple device

A hand-made, radiolucent, custom-designed device having a mobile and a non-mobile platforms was used to objectively quantify the in vivo cranial tibial translation, in order to assess the functional status of cranial-cruciate-ligament (CrCL) in dogs. The hypothesis was that changes in CrCL integrity would result in detectable changes in tibial translation. To validate the diagnostic method, data from injured (PA, n = 32), contralateral (CO, n = 32) and healthy stifles (HE, n = 32) were compared. Normalized tibial translation (Δ_N) of each stifle was measured in medio-lateral radiographic projection obtained before and during standard thrust force application, in PA (43.59±12.97%), CO (20.32±6.69%) and HE (12.22±3.77%). Comparing PA with HE and CO (Δ_N cut-off value: 29.73%), diagnosis could be issued with very high probability. Comparing HE with CO (Δ_N cut-off value: 14.80%), high performance was obtained. The translator device could be a useful tool to objectively quantify the in vivo tibial translation in dogs with CrCL rupture, before surgery and during post-operatory follow-up.

Correlation between orthopaedic and radiographic examination findings and arthroscopic ligament fibre damage in dogs with cruciate ligament rupture

OBJECTIVE

The objective is to study the correlations between physical examination and stifle radiography findings and severity of arthroscopic cranial cruciate ligament (CrCL) fibre damage in dogs with cruciate rupture (CR).

DESIGN

Design Prospective clinical study.

METHODS

Twenty-nine client-owned dogs with CR underwent physical examination, stifle radiography and arthroscopy, and the findings were recorded. Initial examination was repeated after sedation and after general anaesthesia. The Spearman rank correlations of examination variables with diagnostic imaging were examined.

RESULTS

Overall, cranial tibial translation assessed by the tibial compression test in extension showed correlation with arthroscopic CrCL fibre damage (P < 0.05). Correlations between severity of cranial drawer laxity and arthroscopic CrCL fibre damage were not significant. Under general anaesthesia, stifle laxity tests were positively correlated with lameness severity grade (S_R  ≥ 0.41, P < 0.05). Meniscal damage was correlated with pain on the internal rotation of the tibia (S_R = 0.42, P < 0.05) and severity of radiographic osteophytosis (S_R = 0.53, P = 0.01).

CONCLUSION

Detection and estimation of severity of cranial tibial translation enable the diagnosis of CR and also the inference of the severity of CrCL fibre rupture, particularly with the tibial compression test in extension. Severity of joint laxity is best assessed under general anaesthesia. Such knowledge should reduce the risk of misdiagnosis and may enhance early diagnosis and treatment of dogs with CR over time.

Large Animal Models for Anterior Cruciate Ligament Research

Large animal (non-rodent mammal) models are commonly used in ACL research, but no species is currently considered the gold standard. Important considerations when selecting a large animal model include anatomical differences, the natural course of ACL pathology in that species, and biomechanical differences between humans and the chosen model. This article summarizes recent reports related to anatomy, pathology, and biomechanics of the ACL for large animal species (dog, goat, sheep, pig, and rabbit) commonly used in ACL research. Each species has unique features and benefits as well as potential drawbacks, which are highlighted in this review. This information may be useful in the selection process when designing future studies.

Surgical Treatments for Canine Anterior Cruciate Ligament Rupture: Assessing Functional Recovery Through Multibody Comparative Analysis

Anterior cruciate ligament (ACL) deficiency can result in serious degenerative stifle injuries. Although tibial plateau leveling osteotomy (TPLO) is a common method for the surgical treatment of ACL deficiency, alternative osteotomies, such as a leveling osteotomy based on the center of rotation of angulation (CBLO) are described in the literature. However, whether a CBLO could represent a viable alternative to a TPLO remains to be established. The aim of this study is to compare TPLO and CBLO effectiveness in treating ACL rupture. First, a computational multibody model of a physiological stifle was created using three-dimensional surfaces of a medium-sized canine femur, tibia, fibula and patella. Articular contacts were modeled by means of a formulation describing the contact force as function of the interpenetration between surfaces. Moreover, ligaments were represented by vector forces connecting origin and insertion points. The lengths of the ligaments at rest were optimized simulating the drawer test. The ACL-deficient model was obtained by deactivating the ACL related forces in the optimized physiological one. Then, TPLO and CBLO treatments were virtually performed on the pathological stifle. Finally, the drawer test and a weight-bearing squat movement were performed to compare the treatments effectiveness in terms of tibial anteroposterior translation, patellar ligament force, intra-articular compressive force and quadriceps force. Results from drawer test simulations showed that ACL-deficiency causes an increase of the anterior tibial translation by up to 5.2 mm, while no remarkable differences between CBLO and TPLO were recorded. Overall, squat simulations have demonstrated that both treatments lead to an increase of all considered forces compared to the physiological model. Specifically, CBLO and TPLO produce an increase in compressive forces of 54% and 37%, respectively, at 90° flexion. However, TPLO produces higher compressive forces (up to 16%) with respect to CBLO for wider flexion angles ranging from 135° to 117°. Conversely, TPLO generates lower forces in patellar ligament and quadriceps muscle, compared to CBLO. In light of the higher intra-articular compressive force over the physiological walking range of flexion, which was observed to result from TPLO in the current study, the use of this technique should be carefully considered.

Gait and electromyographic alterations due to early onset of injury and eventual rupture of the cranial cruciate ligament in dogs: A pilot study

OBJECTIVE

Identify relevant electromyography (EMG), kinematic, and kinetic changes resulting from monopolar radiofrequency energy (MRFE)-induced cranial cruciate ligament (CCL) injury and eventual rupture in dogs.

STUDY DESIGN

Experimental, repeated measures.

ANIMALS

Five purpose-bred female dogs free of orthopedic and neurologic disease.

METHODS

Surface EMG, joint kinematics, and ground reaction forces were assessed at a trot in the pelvic limbs at baseline, at 2 and 4 weeks after unilateral MRFE-induced CCL injury, and at 4, 8, and 16 weeks after CCL rupture (CCLR).

RESULTS

After MRFE-induced injury, average hip joint range of motion (ROM) during stance decreased within the untreated pelvic limb. After CCLR, stifle flexion angles decreased within the treated limb at 8 weeks and within the untreated pelvic limb at all time points, whereas average tarsal joint ROM decreased in the treated limb and increased in the untreated limb. Peak vertical ground reaction force and impulse decreased within the treated limb. Qualitative alterations of many EMG values were noted after MRFE-induced injury and CCLR, although significant differences between limbs or from baseline values were not detected.

CONCLUSION

Monopolar radiofrequency energy-induced injury altered contralateral hip kinematics, suggesting early regional compensatory gait alterations. After CCLR, additional compensatory gait patterns occurred in both pelvic limbs.

CLINICAL IMPACT

The qualitative analysis of trial-averaged EMG data in this small population supports a relationship between neuromuscular function and induced CCL injury leading to rupture.

Head and pelvic vertical displacement in dogs with induced swinging limb lameness: an experimental study

Background

Swinging limb lameness is defined as a motion disturbance ascribed to a limb in swing phase. Little is known about its biomechanics in dogs, particularly about the body motions that accompany it, such as vertical head and pelvic motion asymmetry. The aim of this study was to describe the changes in vertical head and pelvic motion asymmetry in dogs with induced swinging limb motion disturbance, mimicking a swinging limb lameness. Fore- and hind-limb lameness was induced in ten sound dogs by placing a weight (200 g) proximal to the carpus or tarsus, respectively. Marker-based motion capture by eight infrared light emitting video cameras recorded the dogs when trotting on a treadmill. Body symmetry parameters were calculated, including differences between the two highest positions of the head (HDmax) and pelvis (PDmax) and between the two lowest positions of the head (HDmin) and pelvis (PDmin), with a value of zero indicating perfect symmetry.

Results

Induction of swinging forelimb lameness showed significant changes in HDmax (median and range: sound 1.3 mm [− 4.7 to 3.1], in the left side − 28.5 mm [− 61.2 to − 17.9] and in the right side 20.1 mm [− 4.4 to 47.5]) and, induction of swinging hind limb lameness showed significant changes in PDmax (sound 2.7 mm [− 7.4 to 7.2], in the left side − 10.9 mm [− 22.4 to 0.5] and in the right side 8.6 mm [− 3 to 30]), as well as an increased hip movement asymmetry (sound 1.6 mm [− 8.6 to 19.9], in the left side − 18.1 mm [− 36.7 to 5.4] and in the right side 15 mm [− 20.7 to 32.1]) (P < 0.05).

Conclusions

Induced swinging fore- and hind limb lameness resulted in significant increased asymmetry of the maximal vertical displacement movement of the head and pelvis, due to decreased lifting of the head in forelimb lameness and of the pelvis in hind limb lameness. The results suggest that asymmetry of the maximal vertical displacement of the head and pelvis (i.e. lifting) is a key lameness sign to evaluate during examination of swinging limb lameness.

Three-dimensional kinematics of canine hind limbs: in vivo, biplanar, high-frequency fluoroscopic analysis of four breeds during walking and trotting

The first high-precision 3D in vivo hindlimb kinematic data to be recorded in normal dogs of four different breeds (Beagle, French bulldog, Malinois, Whippet) using biplanar, high-frequency fluoroscopy combined with a 3D optoelectric system followed by a markerless XROMM analysis (Scientific Rotoscoping, SR or 3D-2D registration process) reveal a) 3D hindlimb kinematics to an unprecedented degree of precision and b) substantial limitations to the use of skin marker-based data. We expected hindlimb kinematics to differ in relation to body shape. But, a comparison of the four breeds sets the French bulldog aside from the others in terms of trajectories in the frontal plane (abduction/adduction) and long axis rotation of the femur. French bulldogs translate extensive femoral long axis rotation (>30°) into a strong lateral displacement and rotations about the craniocaudal (roll) and the distal-proximal (yaw) axes of the pelvis in order to compensate for a highly abducted hindlimb position from the beginning of stance. We assume that breeds which exhibit unusual kinematics, especially high femoral abduction, might be susceptible to a higher long-term loading of the cruciate ligaments.

Ex vivo preliminary investigation of radiographic quantitative assessment of cranial tibial displacement at varying degrees of canine stifle flexion with or without an intact cranial cruciate ligament

Background

The presence of cranial tibial subluxation can aid in the detection of joint instability as a result of CrCL injury. Detection of cranial tibial subluxation has been described using the tibial compression test (TCT) and cranial drawer test (CDT); however, diagnosis of CrCL insufficiency by assessing cranial subluxation motion of the tibia is subjective and difficult to quantify accurately. The aim of this study was to investigate a measurement technique to assess the degree of cranial tibial displacement relative to the femoral condyles on mediolateral projection stifle radiographs at varying degrees of stifle flexion (90°, 110°, and 135°) in CrCL intact, partially, and completely transected conditions. Radiographic measurements included: CrCL length and intercondylar distance (ICD), defined as the distance between the tibial mechanical axis (TMA) and the femoral condylar axis (FCA). The influence of CrCL status, stifle flexion angle, and measurement type on measured distance was evaluated. The relationship between CrCL length and ICD measurement was also assessed.

Results

Complete transection of the CrCL resulted in significant cranial tibial displacement. Stifle flexion angle affected ICD, but not CrCL length. Normalized measured CrCL length and ICD were significantly different; however, no differences existed between the change in distance detected by CrCL length and ICD measurements as CrCL transection status changed. Correlation coefficients detected a significant positive correlation between measured CrCL and ICD.

Conclusion

The ICD measurement technique was able to quantify tibial displacement at various stifle flexion angles in the intact and completely transected CrCL conditions. The ICD measurement was more affected by stifle flexion angle than was the CrCL length.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1599-5) contains supplementary material, which is available to authorized users.

Kinematic adaptions to induced short-term pelvic limb lameness in trotting dogs

Background

Lameness due to paw injuries is common in the clinical practice. Although many studies investigated gait adaptations to diseases or injuries, mainly of the hip and knee, our understanding of the biomechanical coping mechanisms that lame dogs utilize is limited. Therefore, this study evaluated the kinematic changes associated with an induced, load-bearing pelvic limb lameness in healthy dogs trotting on a treadmill. Kinematic analysis included spatio-temporal comparisons of limb, joint and segment angles of all limbs. Key parameters compared between sound and lame conditions were: angles at touch-down and lift-off, minimum and maximum joint angles and range of motion.

Results

Significant differences were identified in each limb during both stance and swing phases. The most pronounced differences concerned the affected pelvic limb, followed by the contralateral pelvic limb, the contralateral thoracic limb and, to the least degree, the ipsilateral thoracic limb. The affected limb was retracted more, while the contralateral limb was protracted more, consistent with this limb bearing more body weight in lame dogs.

Conclusions

Kinematic adaptations involved almost all segment and joint angles in the pelvic limbs, while they exclusively concerned distal parts of the thoracic limbs. Comparisons with tripedal locomotion reveal several striking similarities, implying that dogs use similar principles to cope with a partial or a total loss in limb function. Because kinematic alterations occurred in all limbs and not just the affected one, all limbs should be included in routine follow-ups and be part of the diagnostic and therapeutic care of canine patients.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1484-2) contains supplementary material, which is available to authorized users.

Femorotibial kinematics in dogs with cranial cruciate ligament insufficiency: a three-dimensional in-vivo fluoroscopic analysis during walking

BACKGROUND

Cranial cruciate ligament (CrCL) insufficiency is a degenerative condition that is a common cause of pelvic limb lameness and osteoarthritis in dogs. Surgical therapies developed to treat dogs with naturally occurring CrCL insufficiency aim to address the resultant instability, but the in-vivo alterations in stifle kinematics associated with CrCL insufficiency have not been accurately defined. The objective of this study was to quantify the 3-dimensional femorotibial joint kinematics of dogs with naturally occurring cranial cruciate ligament (CrCL) insufficiency during ambulation. Eighteen client-owned dogs (20-40 kg) with natural unilateral complete CrCL rupture were included. Computed tomographic scans were used to create digital 3-dimensional models of the femur and tibia bilaterally for each dog. Lateral fluoroscopic images were obtained during treadmill walking and 3 complete gait cycles were analyzed. Stifle flexion/extension angle, craniocaudal translation, and internal/external rotation were calculated throughout the gait cycle using a previously described 3D-to-2D image registration process. Results were compared between the pre-operative CrCL-deficient and 6-month post-operative contralateral stifles (control).

RESULTS

CrCL-deficient stifles were maintained in greater flexion throughout the gait cycle. Cranial tibial subluxation was evident in CrCL-deficient stifles at all time points throughout the gait cycle [9.7 mm at mid-stance (P < 0.0001); 2.1 mm at mid-swing (P < 0.0017)], and the magnitude of cranial tibial subluxation was greater at mid-stance phase than at mid-swing phase (P < 0.0001). Greater internal tibial rotation was present in CrCL-deficient stifles during stance phase (P < 0.0022) but no difference in axial rotation was evident during swing phase.

CONCLUSIONS

Naturally occurring CrCL rupture causes profound craniocaudal translational and axial rotational instability, which is most pronounced during the stance phase of gait. Surgical stabilization techniques should aim to resolve both craniocaudal subluxation and axial rotational instability.

The precision and repeatability of a custom-made pointer device for determination of virtual landmarks in canine three-dimensional kinematics

Placement of markers on anatomical landmarks represents a large source of error in three-dimensional kinematics. Our objectives were to test the accuracy and precision of a custom-made pointer and compare it to conventional skin markers in dogs. The pointer was first assessed by pointing at the surface of a spherical marker of known dimensions and position in space. Secondly, a point located cranio-distally to the lateral epicondyle was marked in 12 canine elbows with a Steinmann pin and reflective markers. Ability to locate a landmark was compared between the pointer and skin-mounted marker. The distance between experimental and true locations was compared between the two methods. A sphere was mathematically fitted through 29 collected points on the spherical marker. Centre, diameter and volume overlap of the fitted sphere were compared to that of the marker. A 0.729 mm bias was found indicating good accuracy. Residual values were small indicating good precision. The average distance between the true and experimental position of the anatomical landmarks were 9.55 ± 4.20 mm and 9.32 ± 3.28 mm for the pointer and the marker respectively. No significant differences were observed between the two methods. The pointer proved to be accurate and reliable for localizing virtual points and was at least equivalent to skin mounted markers for the detection of anatomical landmarks in the dog. It should prove useful in the localization of anatomical landmarks for kinematic analysis.

Kinematic gait analysis of the canine thoracic limb using a six degrees of freedom marker set

Objectives: To determine if the use of a six degrees of freedom marker set would allow new kinematic data of the canine thoracic limbs to be calculated. To identify any significant differences in thoracic limb gait patterns in all planes of motion, between the normal canine population and patients with confirmed medial coronoid disease (MCD).

Method: Two groups of dogs were selected representing the normal Labrador Retriever population (n = 13) and Labrador Retrievers with confirmed MCD (n = 13). Normal dogs had “normal” hip and elbow radiographic scores in line with the International Elbow Working Group and British Veterinary Association guidelines. Medial coronoid disease was confirmed using arthroscopy after kinematic analysis was performed with a six degrees of freedom marker set.

Results: The diseased elbow was nine degrees more extended between 43%-55% of the gait cycle and 16° more supinated prior, early during and after foot strike. The antebrachium was nine degrees more supinated during foot strike and three degrees more abducted during early stance. None of the other parameters were significantly different.

Clinical significance: The use of a six degrees of freedom marker set made it possible for the elbow and antebrachium to be reliably tracked in more than one plane of motion. Significant differences were identified between the normal canine population and those affected by MCD. These data may help elucidate biomechanical factors contributing to aetiopathogenesis of MCD.

The effects of a novel lateral extracapsular suture system on the kinematics of the cranial cruciate deficient canine stifle

Objective To evaluate the relative position of the femur and tibia in cranial cruciate ligament- intact stifles, cranial cruciate ligamentdeficient stifles, and cruciate-deficient stifles following lateral extracapsular suture system (LESS) stabilization under load at specific joint angles.

Study design In vitro biomechanical study.

Methods Twenty pelvic limbs from 11 dogs were used to evaluate the relative position of the femur and tibia between three stifle conditions (cranial cruciate ligament-intact, cranial cruciate ligament-deficient, and LESSstabilized) at a load of 30% of body weight and stifle angles of 125°, 135°, and 145° using electromagnetic tracking sensors.

Results Cranial cruciate ligament-deficient stifles had significantly greater (p <0.0001) cranial displacement and internal rotation of the tibia relative to the femur than cranial cruciate ligament-intact or LESS stifles at all stifle angles. Cranial displacement of the tibia relative to the femur for cranial cruciate ligament-intact and LESS stifles were not significantly different from one another at a stifle angle of 125°, but were significantly different at stifle angles of 135° (p = 0.0182) and 145° (p = 0.0012). There was no significant difference in internal rotation of the tibia relative to the femur between the cranial cruciate ligament-intact and LESS stifles at any of the stifle angles.

Clinical significance The LESS procedure effectively decreased cranial tibial displacement and eliminated internal rotation of the tibia relative to the femur in the cranial cruciate ligament-deficient stifles at stifle angles of 125°, 135°, and 145° in vitro.

A review of extra-articular prosthetic stabilization of the cranial cruciate ligament-deficient stifle

Extra-articular prosthetic stabilization techniques have been used as a method of stabilization of the cranial cruciate ligament (CrCL)-deficient stifle for decades. During extra-articular prosthetic stabilization, the prosthesis is anchored to the femur and tibia, and tensioned in the attempt to resolve femorotibial instability. The position of the anchor points of the prosthesis is crucial for restoring a normal range of joint motion and mitigating alterations in prosthesis tension during motion. Recently developed techniques offer several innovations with potential advantages such as bone-to-bone fixation, prosthetic materials with better mechanical properties, and improved isometry of the anchor points. Whether these innovations provide clinically superior results to the traditional techniques such as lateral circumfabellar-tibial suture techniques has yet to be determined.

Retrospective study of 476 tibial plateau levelling osteotomy procedures

Objective: To determine the rate of subsequent ‘pivot shift’, meniscal tear and risk factors associated with complications of tibial plateau levelling osteotomy (TPLO) and to assess clinical and owner perception outcome.

Study design: Retrospective study.

Sample population: Three hundred and forty-eight dogs that had undergone TPLO surgical procedures (n = 476 stifles).

Methods: Medical records were reviewed for the retrieval of information on breed, sex, age, body weight, clinical history, radiograph findings, pre- and postoperative tibial plateau angle, limb alignment, unilateral versus bilateral disease, condition of cranial cruciate ligament (CCL) and menisci, implant material, healing time and complications. Clinical and owner-assessed questionnaire outcomes were also recorded.

Results: Forty-six (9.7%) postoperative complications were reported. Twenty (4.2%) were classified as major complications requiring an additional surgical intervention, and 26 (5.5%) as minor complications. No risk factors associated with postoperative complications were identified. Ten (2.1%) subsequent meniscal injuries in the stifles with normal unaltered menisci at time of TPLO were reported with a median postoperative time of 9.5 months. Signs of postoperative ‘pivot shift’ were reported in 15 (3.1%) stifles. All stifles with a ‘pivot shift’ had a complete CCL rupture or a debrided partial CCL rupture a medial menisectomy was identified as a risk factor for a ‘pivot shift’ (p = 0.02). Dogs with intact medial meniscus had a significantly higher activity level (p <0.0001) and a shorter time to peak function (p = 0.02) than dogs that underwent menisectomy according to an owner questionnaire.

Conclusions: Dogs with TPLO and intact meniscus seemed to have a better and faster recovery than dogs with TPLO and menisectomy based on owner questionnaires. ‘Pivot shift’ was infrequent after TPLO surgery. All dogs with a ‘pivot shift’ had a complete CCL rupture or a debrided partial CCL rupture and menisectomy was identified as a risk factor for its occurrence.

Clinical relevance: Considering the relatively low rate of subsequent meniscal injury after TPLO, systematic medial meniscal release with TPLO may be unnecessary. The ‘pivot shift’ deserved further investigation to completely understand its mechanism, to identify its anatomic components and potential consequences on the stifle joint.

Effect of Limb Position at the Time of Skin Marker Application on Sagittal Plane Kinematics of the Dog

Objectives To evaluate the effect of limb position during initial skin marker application on sagittal plane kinematics of the hindlimb.

Methods Six healthy dogs (20–30 kg) were evaluated. An established two-dimensional kinematic model of the pelvic limb was utilized to describe sagittal plane motion. Kinematic markers were applied separately for each dog while standing in three different positions: (1) the limb extended cranially, (2) a normal standing limb position and (3) the limb extended caudally. Following marker application at each of the three positions, dynamic gait was recorded at a walk (velocity, 0.9–1.2 m/s; acceleration, 0.5m/s ² ). Five valid trials were used for comparison. Complete waveform analysis was performed with generalized indicator function analysis (GIFA). Maximum and minimum joint angles and joint range of motion were compared with a one-way repeated measures ANOVA with significance at p < 0.05.

Results Significant differences were found between stifle waveforms. No differences were found between the hip or tarsus waveforms. Minimum and maximum joint angles were significantly different for the hip and stifle but not for the tarsus. No differences were found between ranges of motion for any joint evaluated.

Clinical Significance Limb position at the time of skin marker application affects gait data and is an important consideration for kinematic analysis of the hindlimb in dogs.

Patellofemoral kinematics in dogs with cranial cruciate ligament insufficiency: an in-vivo fluoroscopic analysis during walking

Background

Complete rupture of the cranial cruciate ligament (CrCL) in dogs causes profound disturbance to stifle joint biomechanics. The objective of this study was to characterize the effects of cranial cruciate ligament (CrCL) insufficiency on patellofemoral (PF) kinematics in dogs during walking. Ten client-owned dogs (20-40 kg) with natural unilateral complete CrCL rupture were included. Dogs underwent computed tomographic scans to create digital bone-models of the patella and femur. Lateral projection fluoroscopy of the stifles was performed during treadmill walking. Sagittal plane PF kinematics were calculated throughout the gait cycle by overlaying digital bone models on fluoroscopic images using a previously described 2D-3D registration technique. For acquisition of kinematics in the contralateral (control) stifle, fluoroscopy was repeated 6-months after stabilizing surgery of the affected side. Results were compared between the pre-operative CrCL-deficient and 6-month post-operative control stifles.

Results

Craniocaudal PF translation was similar between CrCL-deficient and control stifles throughout the gait cycle. The patella was more distal and positioned in greater flexion throughout the gait cycle in CrCL-deficient stifles when compared to the control stifle at equivalent time points. There was no significant difference in PF poses between CrCL-deficient and control stifles at equivalent femorotibial flexion angles; however, common femorotibial flexion angles were only found over a small range during the swing phase of gait.

Conclusions

CrCL insufficiency altered PF kinematics during walking, where the changes were predominately attributable to the femorotibial joint being held in more flexion. Abnormal PF kinematics may play a role in the development of osteoarthritis that is commonly observed in the PF joint CrCL-deficient stifles.

Use of a novel extracapsular bone anchor system for stabilisation of cranial cruciate ligament insufficiency

OBJECTIVES

To evaluate early clinical experiences using the novel extracapsular bone anchor Ruby system for stabilisation of the cranial cruciate ligament deficient stifle in the dog and report short-term outcome and complications for 17 clinical cases.

MATERIALS AND METHODS

Seventeen dogs with cranial cruciate ligament insufficiency were treated using the Ruby system. Dogs were eligible if diagnosed via orthopaedic examination with unilateral or bilateral cranial cruciate ligament instability without any comorbidities. Subjective lameness assessments on a 0 to 4 scale were made pre-operatively and at six to eight weeks post-operatively; complications were also recorded. Lameness was also assessed on a visual analogue scale at six to eight months post-operatively.

RESULTS

All cases had substantial improvement in lameness following surgery. Mean post-operative lameness grade was 1·18 (±0·53) out of 4, compared to a grade of 3·06 (±0·9) before surgery, and owner assessment at six to eight months after surgery was also positive. There were major complications that required surgical intervention in one dog.

CLINICAL SIGNIFICANCE

The Ruby system is a feasible method of extracapsular stabilisation with comparable outcomes and complication rates to previously reported methods of addressing cranial cruciate ligament insufficiency. Further work is required to acquire more data on objective outcome measurement and mechanisms of failure.

Pelvic limb kinematics in the dog with and without a stifle orthosis

OBJECTIVE

To report a method of evaluating 3-dimensional joint motion in dogs with a stifle orthosis.

STUDY DESIGN

Experimental.

ANIMALS

Six healthy dogs.

METHODS

Three-dimensional pelvic limb joint motion was recorded with and without a stifle orthosis. Kinematic data were collected from dogs at a walk and trot for the hip, stifle, and tarsus prior to, and after application of, a stifle orthosis. Data were also obtained for the orthosis alone. Comparisons were made between the braced and unbraced limb, and between the braced limb and the orthosis alone. Complete waveforms, kinematic, and temporospatial variables were compared.

RESULTS

Gait waveforms differed between braced and unbraced limbs for all joints and planes of motion (P < .05), as well as between the braced stifles and the orthosis alone at both a walk and trot. However, joint ROM was inconsistently altered. The effect of bracing on stifle ROM was limited to a reduced extension at the end of stance. Adjacent joint ROM was affected by the stifle orthosis. Temporospatial variables were predominantly affected while walking.

CONCLUSIONS

The restrictive motion of the stifle orthosis is not fully translated to the underlying joint, based on the limited differences between the motion of braced and unbraced stifles. This effect varies with plane of motion and phase of the gait cycle, with most changes in stifle motion being detected during the stance phase. The stifle orthosis had an equal or greater effect on the motion of adjacent joints, especially the tarsus.

Biomechanics of an orthosis-managed cranial cruciate ligament-deficient canine stifle joint predicted by use of a computer model

OBJECTIVE To evaluate effects of an orthosis on biomechanics of a cranial cruciate ligament (CrCL)-deficient canine stifle joint by use of a 3-D quasistatic rigid-body pelvic limb computer model simulating the stance phase of gait and to investigate influences of orthosis hinge stiffness (durometer). SAMPLE A previously developed computer simulation model for a healthy 33-kg 5-year-old neutered Golden Retriever. PROCEDURES A custom stifle joint orthosis was implemented in the CrCL-deficient pelvic limb computer simulation model. Ligament loads, relative tibial translation, and relative tibial rotation in the orthosis-stabilized stifle joint (baseline scenario; high-durometer hinge]) were determined and compared with values for CrCL-intact and CrCL-deficient stifle joints. Sensitivity analysis was conducted to evaluate the influence of orthosis hinge stiffness on model outcome measures. RESULTS The orthosis decreased loads placed on the caudal cruciate and lateral collateral ligaments and increased load placed on the medial collateral ligament, compared with loads for the CrCL-intact stifle joint. Ligament loads were decreased in the orthosis-managed CrCL-deficient stifle joint, compared with loads for the CrCL-deficient stifle joint. Relative tibial translation and rotation decreased but were not eliminated after orthosis management. Increased orthosis hinge stiffness reduced tibial translation and rotation, whereas decreased hinge stiffness increased internal tibial rotation, compared with values for the baseline scenario. CONCLUSIONS AND CLINICAL RELEVANCE Stifle joint biomechanics were improved following orthosis implementation, compared with biomechanics of the CrCL-deficient stifle joint. Orthosis hinge stiffness influenced stifle joint biomechanics. An orthosis may be a viable option to stabilize a CrCL-deficient canine stifle joint.

Partial Cranial Cruciate Ligament Tears Treated with Stem Cell and Platelet-Rich Plasma Combination Therapy in 36 Dogs: A Retrospective Study

Objective

To evaluate outcomes in 36 dogs with a partial cranial cruciate ligament (CCL) tear treated with autologous bone marrow aspirate concentrate (BMAC) or adipose-derived progenitor cells (ADPC) with platelet-rich plasma (PRP) combination.

Materials and methods

Medical records of client-owned dogs diagnosed with an early partial (≤50%) tear of the craniomedial band of the CCL that was treated with BMAC–PRP or ADPC–PRP were reviewed from 2010 to 2015. Signalment, medical history, physical and orthopedic examination, objective temporospatial gait analyses, radiographs, day 0 and day 90 diagnostic arthroscopy findings, treatment, and outcome were among the data collected. A functional owner questionnaire, including the validated Helsinki chronic pain index (HCPI), was sent to owners whose dog was known to not have had a tibial plateau leveling osteotomy (TPLO). Statistical analysis was performed on data, where significance was established at p < 0.05.

Results

Stifle arthroscopy findings at 90 days posttreatment were available on 13 of the 36 dogs. In nine dogs, a fully intact CCL with marked neovascularization and a normal fiber pattern was found with all previous regions of disruption healed. One dog revealed significant improvement and received an additional injection. The remaining three dogs had a >50% CCL tear, and a TPLO was performed. Four additional dogs were known to have had a TPLO performed elsewhere. Baseline and day 90 posttreatment objective gait analyses were available on 11 of the 36 dogs. A significant difference was found between the treated limb total pressure index percent (TPI%) at day 0 and day 90 (p = 0.0124), and between the treated limb and contralateral limb TPI% at day 0 (p = 0.0003). No significant difference was found between the treated limb and contralateral limb TPI% at day 90 (p = 0.7466). Twelve questionnaires were returned, of which eight were performance/sporting dogs. Seven of the eight had returned to sport; the remaining dog had just begun a return to sport conditioning program 6 months posttreatment. All 12 respondents believed that their dog had an excellent or very good quality of life and rated their dog’s procedural outcome as excellent or good.

Conclusion

The use of BMAC–PRP and ADPC–PRP shows promise for the treatment of early partial CCL tears in dogs. Further studies are needed and should be randomized, blinded, and controlled.

Evaluation of the relationship of tibiofemoral kinematics before and after total knee replacement in an in vitro model of cranial cruciate deficiency in the dog

OBJECTIVE

To investigate the relationship between tibiofemoral kinematics before and after total knee replacement (TKR) in vitro.

ANIMALS

Eight canine hemipelves.

METHODS

A modified Oxford Knee Rig was used to place cadaveric limbs through a range of passive motion allowing the kinematics of the stifle to be evaluated. Four measurements were performed: a control stage, followed by a cranial cruciate transection stage, then following TKR with the musculature intact stage, and finally TKR with removal of limb musculature stage. Joint angles and translations of the femur relative to the tibia, including flexion-extension versus adduction-abduction, flexion-extension versus internal-external rotation, as well as flexion-extension versus each translation (cranial-caudal and lateral-medial) were calculated.

RESULTS

Significant differences were identified in kinematic data from limbs following TKR implantation as compared to the unaltered stifle. The TKR resulted in significant decreases in external rotation of the stifle during flexion-extension compared to the limb prior to any intervention, as well as increasing the abduction. The TKR significantly increased the caudal translation of the femur relative to the tibia compared to the unaltered limb. When compared with the cranial cruciate ligament-transection stage, TKR significantly decreased the ratio of the external rotation to flexion.

DISCUSSION

All three test periods showed significant differences from the unaltered stifle. The TKR did not completely restore the normal kinematics of the stifle.

Owner Evaluation of a CORA-Based Leveling Osteotomy for Treatment of Cranial Cruciate Ligament Injury in Dogs

OBJECTIVE

To evaluate a center of rotation of angulation (CORA)-based leveling osteotomy for cranial cruciate ligament injury in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n=70).

METHODS

Medical records (March 2011 to March 2012) of dogs diagnosed with a cranial cruciate ligament (CCL) injury treated with a CORA-based leveling osteotomy and stabilized using a bone plate and headless compression screw were reviewed. Radiographs were reviewed for tibial plateau angle and radiographic healing at final evaluation graded on a 5-point scale. Follow-up for a minimum of 6 months postoperatively was conducted by owner completion of a questionnaire regarding their dog's function after surgery. Based on owner responses, clinical outcomes were established.

RESULTS

CORA-based leveling osteotomy was used for 70 stifles with CCL injury. The mean time to final radiographic recheck was 107 days (range, 32-424 days). Radiographic healing scores were 42 dogs (69%) with grade 4, 17 dogs (28%) with grade 3, and 2 dogs (3%) with grade 2. The mean time to follow-up was 11.9 months (range 6-18 months). Fifty-four of the 70 (77%) dogs had full function, 13 (19%) had acceptable function, and 3 (4%) had unacceptable function. Complications occurred in 11 stifles (16%), including 3 incisional, 6 late-onset meniscal tears, and 2 implant related.

CONCLUSION

The described method of a CORA-based leveling osteotomy can be successfully performed for treatment of CCL injury in dogs. At the time of mid-term and long-term owner follow-up, most dogs in this case series had returned to full function.

Canine Stifle Biomechanics Associated With a Novel Extracapsular Articulating Implant Predicted Using a Computer Model

OBJECTIVE

To evaluate the influence of the Simitri Stable in Stride™ extracapsular articulating implant (EAI) on canine stifle biomechanics in the cranial cruciate ligament (CrCL)-deficient stifle using a 3-dimensional (3D) quasi-static rigid body canine pelvic limb computer model simulating the stance phase of gait.

STUDY DESIGN

Computer simulations.

ANIMALS

Five-year-old neutered male golden retriever (33 kg).

METHODS

The EAI was implemented in a previously developed 3D CrCL-deficient canine pelvic limb computer simulation model. Ligament loads, relative tibial translation, and relative tibial rotation were determined and compared to the CrCL-intact and CrCL-deficient stifle.

RESULTS

The EAI significantly increased peak caudal cruciate and medial collateral ligament loads, significantly changed when peak lateral collateral ligament load occurred, and did not significantly affect peak patellar ligament load compared to the CrCL-intact stifle. Compared to the CrCL-deficient stifle, peak caudal cruciate, lateral collateral, and medial collateral ligament loads significantly decreased in the EAI-managed stifle. Despite decreased peak caudal cruciate ligament loading, the EAI-managed stifle generated local maxima that exceeded those of the CrCL-deficient stifle at various intervals of stance. Peak relative tibial translation and rotation significantly decreased in the EAI-managed stifle compared to the CrCL-deficient stifle.

CONCLUSION

Model-predicted stifle biomechanics differed after EAI system application in the CrCL-deficient stifle, but were not restored to that of the CrCL-intact stifle.

In-vivo three-dimensional knee kinematics during daily activities in dogs

The canine knee is morphologically similar to the human knee and thus dogs have been used in experimental models to study human knee pathology. To date, there is limited data of normal canine 3D knee kinematics during daily activities. The objective of this study was to characterize 3D in-vivo femorotibial kinematics in normal dogs during commonly performed daily activities. Using single-plane fluoroscopy, six normal dogs were imaged performing walk, trot, sit, and stair ascent activities. CT-generated bone models were used for kinematic measurement using a 3D-to-2D model registration technique. Increasing knee flexion angle was typically associated with increasing tibial internal rotation, abduction and anterior translation during all four activities. The precise relationship between flexion angle and these movements varied both within and between activities. Significant differences in axial rotation and coronal angulation were found at the same flexion angle during different phases of the walk and trot. This was also found with anterior tibial translation during the trot only. Normal canine knees accommodate motion in all planes; precise kinematics within this envelope of motion are activity dependent. This data establishes the characteristics of normal 3D femorotibial joint kinematics in dogs that can be used as a comparison for future studies.

Preactivation of the quadriceps muscle could limit cranial tibial translation in a cranial cruciate ligament deficient canine stifle

Cranial cruciate ligament (CrCL) deficiency is the leading cause of lameness of the canine stifle. Application of tension in the quadriceps muscle could trigger cranial tibial translation in case of CrCL rupture. We replaced the quadriceps muscle and the gastrocnemius muscle by load cells and turn-buckles. First, eight canine limbs were placed in a servo-hydraulic testing machine, which applied 50% of body weight (BW). In a second phase, the CrCL was transected, and the limbs were tested in a similar manner. In a third phase, a quadriceps pretension of 15% BW was applied and limbs were again tested in a similar manner. Cranial tibial translation was significantly decreased in CrCL deficient stifles (p < 0.05) when quadriceps pretension was applied. These findings indicate that quadriceps pretension could play a role in the stability of a CrCL deficient stifle and should then be considered in rehabilitation programs and conservative treatment of CrCL rupture in dogs.

Use of an inverse dynamics method to compare the three-dimensional motion of the pelvic limb among clinically normal dogs and dogs with cranial cruciate ligament-deficient stifle joints following tibial plateau leveling osteotomy or lateral fabellar-tibial suture stabilization

OBJECTIVE

To compare the 3-D motion of the pelvic limb among clinically normal dogs and dogs with cranial cruciate ligament (CCL)-deficient stifle joints following tibial plateau leveling osteotomy (TPLO) or lateral fabellar-tibial suture (LFS) stabilization by use of an inverse dynamics method.

ANIMALS

6 clinically normal dogs and 19 dogs with CCL-deficient stifle joints that had undergone TPLO (n = 13) or LFS (6) stabilization at a mean of 4 and 8 years, respectively, prior to evaluation.

PROCEDURES

For all dogs, an inverse dynamics method was used to describe the motion of the pelvic limbs in the sagittal, frontal, and transverse planes. Motion and energy patterns for the hip, stifle, and tibiotarsal (hock) joints in all 3 planes were compared among the 3 groups.

RESULTS

Compared with corresponding variables for clinically normal dogs, the hip joint was more extended at the beginning of the stance phase in the sagittal plane for dogs that had a TPLO performed and the maximum power across the stifle joint in the frontal plane was greater for dogs that had an LFS procedure performed. Otherwise, variables in all planes were similar among the 3 groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Gait characteristics of the pelvic limb did not differ between dogs that underwent TPLO and dogs that underwent an LFS procedure for CCL repair and were similar to those of clinically normal dogs. Both TPLO and LFS successfully provided long-term stabilization of CCL-deficient stifle joints of dogs with minimal alterations in gait.