Desmitis of the medial tarsal collateral ligament in 7 horses

Severe lameness, tarsocrural joint effusion and medially focused peritarsal swelling combined with focal pain on palpation are clinical signs suggestive of acute injury to the medial tarsal collateral ligament. Diagnosis can be made on physical examination and ultrasonographic findings; however, magnetic resonance imaging may provide more information especially with subtle injury. Acute exacerbation of the injury during the prolonged convalescence is common. The prognosis for medial tarsal collateral ligament desmitis appears good for survival but fair for return to previous levels of performance and requires prolonged periods of rest and a controlled exercise programme.     

Surgical reconstruction of a ruptured medial collateral ligament in a foal

An avulsed carpal medial collateral ligament was diagnosed by clinical and radiographic examination in a 1-day-old foal that was unable to bear weight on the affected limb. The foal had a valgus deviation originating at the carpus and medial to lateral instability of the affected carpus. The ligament was reconstructed with screws and suture tape. Surgical reconstruction is a viable alternative to long-term casting or splinting for treatment of a ruptured carpal medial collateral ligament in a foal.     

Biomechanical comparison of a circular external skeletal fixator construct to pin and tension band wire fixation for the stabilization of olecranon osteotomies in dogs: a cadaveric study

OBJECTIVE: To compare anatomic reduction and the biomechanical properties of a circular external skeletal fixator (CESF) construct to pin and tension band wire (PTBW) fixation for the stabilization of olecranon osteotomies in dogs. STUDY DESIGN: Cadaveric study. ANIMALS: Forelimbs from 12 skeletally mature mixed-breed dogs, weighing 23 to 28 kg. METHODS: An olecranon osteotomy was stabilized with either a CESF construct or PTBW fixation. A single distractive load to failure was applied to each specimen through the triceps tendon. Osteotomy reduction and biomechanical properties were compared between fixation groups. RESULTS: Reduction was not significantly different (gap: P =.171; malalignment: P =.558) between fixation groups. Osteotomies stabilized with the CESF had greater stiffness (P <.0001) and maximum load sustained (P <.0001) compared to PTBW fixation. There was no significant difference for yield load (P =.318) or for load at 1 mm of axial displacement (P =.997) between fixation groups. Failure of fixation occurred by bending of the intramedullary Steinmann pin and the fixation wires in the CESF specimens and by untwisting of the tension band wire knot with pullout and bending of the Kirschner wires in the PTBW specimens. CONCLUSIONS: Specimens stabilized with the CESF construct had similar reduction and yield load, greater stiffness and maximum load sustained, and less elastic deformation than specimens stabilized with PTBW fixation. CLINICAL RELEVANCE: The CESF construct may provide a biomechanically favorable alternative to PTBW fixation for stabilization of olecranon osteotomies in dogs, and its application warrants clinical investigation.     

Treatment of a ruptured medial collateral ligament of the stifle in a horse

Medial collateral ligament ruptures in horses are rare and difficult to treat. Conservative treatment usually results in degenerative joint disease that causes permanent lameness. Surgical treatment may be an alternative for salvaging horses for breeding purpose.     

Nitric oxide and metalloproteinases in canine articular ligaments: a comparison between the cranial cruciate, the medial genual collateral and the femoral head ligament

Osteoarthritis due to cranial cruciate ligament (CCL) rupture or hip dysplasia is one of the most important causes of chronic lameness in dogs. This study aimed at comparing nitric oxide (NO) production by the CCL with that of the femoral head ligament (FHL) and the medial collateral ligament (MCL), and investigating the pathway of NO production and the concomitant metalloproteinase (MMP) activity in the presence or absence of an inflammatory stimulus. Ligaments of normal dogs were subjected to different stimuli, and NO and MMP activity from explant culture supernatants were compared. The results showed that in explant cultures of the canine CCL more NO was produced than in those of the other two ligaments. A higher level of NO was produced when CCLs were exposed to the inducible nitric oxide synthase (iNOS)-inducing cocktail TNF/IL-1/LPS, and NO synthesis could be inhibited by both l-NMMA, a general nitric oxide synthase (NOS) inhibitor and l-NIL, a specific iNOS inhibitor. However, a correlation between NO synthesis and iNOS expression levels as determined by immunohistochemistry was not observed. In contrast to CCL, no evidence for iNOS-dependent NO synthesis was observed for MCL and FHL. The CCL produced less MMP than MCL and FHL, and no correlation between MMP and NO could be demonstrated. MMP activity in the CCL increased significantly after 48 h of incubation with the inflammatory stimulus. The results suggest that in canine osteoarthritis NO synthesized by canine CCL plays a more important role in the pathogenesis of osteoarthritis of the stifle than that synthesized by FHL and MCL.     

A preliminary trial comparison of several anesthetic techniques in cats

The aim of this study was to investigate the effect of several drug combinations (atropine, xylazine, romifidine, methotrimeprazine, midazolam, or fentanyl) with ketamine for short term anesthesia in cats. Twelve cats were anesthetized 6 times by using a cross-over Latin square protocol: methotrimeprazine was combined with midazolam, ketamine, and fentanyl; midazolam and ketamine; romifidine and ketamine; and xylazine and ketamine. Atropine was combined with romifidine and ketamine, and xylazine and ketamine. Temperature, heart rate, and respiratory rate decreased in all groups. Apnea occurred in 1 cat treated with methotrimeprazine, romifidine, and ketamine, suggesting that ventilatory support may be necessary when this protocol is used. Emesis occurred in some cats treated with alpha 2-adrenoceptor agonists, and this side effect should be considered when these drugs are used.     

Trauma resulting in hemarthrosis and long medial collateral ligament desmitis of the tarsocrural joint in a horse

A horse was initially diagnosed with hemarthrosis and desmitis of the long medial collateral ligament of the right tarsus and later developed prominent enthesiophytosis at the site of insertion of the ligament's deep portion. Hemarthrosis due to intra- or peri-articular pathology can cause recurrent lameness, even without evident external trauma.     

Temporo-mandibular joint condylectomy and its effect over occlusion in cats: cadaveric study

Objective : To determine the effect of unilateral condylectomy on dental occlusion in cats. Methods : Twelve feline cadaver heads were randomly submitted to either a right or left unilateral condylectomy of the temporo‐mandibular joint. The distance between the mandibular and maxillary canine tooth was measured before (B0) and after the unilateral condylectomy (P0). A right or left latero‐‐lateral standardised force (4 N) was applied to the mandibular mentus area before and after the surgical procedure. These measurements were analysed with a linear model for repeated measures. Results : The comparative analysis between pre‐ and postsurgical values indicated no significant variation in teeth displacement following condylectomy between B0 and P0 measurements. Statistically significant differences were detected after either left or right condylectomy with respect to all measurements after application of the standardised forces. Occlusion changes are significant when comparing bites before and after surgery. Clinical Significance : Unilateral condylectomy causes a significant increase in latero‐lateral amplitude of jaw movement which might clinically affect feline dental occlusion. Clinical studies are required to determine the effect of unilateral condylectomies on mastication and dental occlusion in feline patients.     

Feline talocrural luxation: a cadaveric study of repair using ligament prostheses

Currently recommended surgical techniques to treat severe biaxial feline talocrural soft-tissue injuries commonly lead to unsatisfactory outcome. Data relating to canine talocrural stabilisation may not be useful in cats due to major differences in tarsal anatomy between the species. This experimental biomechanical cadaveric study used specimens (n = 10) prepared from the distal pelvic limbs of five adult cats. The aim was to design a technique for treating talocrural luxation using suture prostheses and bone tunnels, and to investigate its suitability for use in clinical cases. Four prosthetic ligaments were placed through a series of five 1.5 mm bone tunnels. Two prostheses, the caudoproximal pair, were taut in talocrural flexion and two prostheses, the craniodistal pair, were taut in extension. The intact specimens had their range-of-motion (ROM) and stability tested, after which they were transected at the talocrural joint (simulated luxation) and repaired using the technique described. The ROM and stability of the repaired specimens were tested and compared to the intact specimens. The repaired specimens had comparable stability to the intact specimens, although the ROM was different (p <0.05) in six of 16 positions (p <0.003125). These corresponded to the positions where the lateral prostheses were taut. The repair technique described may be useful in the treatment of talocrural luxation, as it is low-profile in an area of limited soft-tissue cover, allows anatomic reduction, restores normal talocrural joint stability and near-normal tarsal ROM.     

Development of an ultrasound-guided transgluteal injection of the pudendal nerve in cats: a cadaveric study

ObjectiveTo develop an ultrasound-guided interfascial plane technique for injection of the pudendal nerve near its sacral origin in cats.Study designProspective, randomized, anatomical study.AnimalsA group of 12 feline cadavers.MethodsGross and ultrasound anatomy of the ischiorectal fossa, the pudendal nerve relationship with parasacral structures, and the interfascial plane were described. Computed tomography was employed to describe a cranial transgluteal approach to the pudendal nerve. Bilateral ultrasound-guided injections were performed in eight cadavers using low [(LV) 0.1 mL kg^–1] or high volume [(HV) 0.2 mL kg^–1] of ropivacaine–dye solution. Dissections were performed to determine successful staining of the pudendal nerve (>1 cm) and inadvertent staining of the sciatic nerve, and any rectal, urethral, or intravascular puncture. Pudendal nerve staining in groups LV and HV were compared using Fisher's exact and Wilcoxon rank-sum test as appropriate (p = 0.05).ResultsThe pudendal nerve and its rectal perineal and sensory branches coursed through the ischiorectal fossa, dorsomedial to the ischiatic spine. The pudendal nerve was not identified ultrasonographically, but the target plane was identified between the sacral transverse process, the ischiatic spine, the pelvic fascia and the rectum, and it was filled with dye solution. Both branches of the pudendal nerve were completely stained 75% and 87.5% in groups LV and HV, respectively (p = 1.00). The dorsal aspect of the sciatic nerve was partially stained in 37% of injections in group HV. Rectal or urethral puncture and intravascular injection were not observed.Conclusions and clinical relevanceIn cats, ultrasound-guided cranial transgluteal injection successfully stained the pudendal nerve in at least 75% of attempts, regardless of injectate volume. Group HV had a greater probability of sciatic nerve staining.     

Successful closed reduction and conservative management with traumatic elbow luxation and medial collateral ligament rupture in an equid

A 9-year-old donkey jenny (212 kg) presented with an acute, nonweight-bearing left forelimb lameness of 24- to 36-h duration. The limb was held in flexion and abduction, with the toe above the ground, and was unable to be manually straightened. There was significant palpable swelling along the medial aspect of the elbow joint. Radiographic evaluation revealed a medial luxation of the elbow joint with rupture of the medial collateral ligament. Closed reduction was accomplished under injectable anaesthesia without complication. The patient was weight-bearing and comfortable on the limb immediately upon recovery from anaesthesia. The jenny was tied and kept standing for 60 days. Full limb bandages, splints (extending proximal to the scapula), hobbles, NSAIDs and cold laser therapy were utilised, decreased and discontinued. At 74 days, a rehab programme was initiated. At 8 months post-injury, the patient was not lame and was back to her previous level of exercise. Although elbow luxation has been described as having a guarded prognosis, there has now been success in 4/5 (80%) reported cases when treatment has been attempted. Closed reduction without surgical intervention in adult animals with elbow luxation can be successful, likely dependent on the level of associated injury.     

Simple techniques for the internal stabilization of fractures and luxations in the sacrococcygeal region of cats and dogs.]

Two useful techniques for the repair of caudal sacral fractures and sacrococcygeal fractures/luxations are described. Pre- and postoperative clinical, neurological and radiological findings in 16 operated animals (13 cats and 3 dogs) were compared with findings in 17 (13 cats and 4 dogs) conservatively treated animals. In the surgically treated patients follow up findings were characterized by absence of hyperesthesia and a higher number of animals with recovered tail function. The authors suggest the use of these techniques in cases of caudal sacral fractures or sacrococcygeal fractures/luxations.     

Retrobulbar and peribulbar regional techniques in cats: a preliminary study in cadavers

ObjectiveTo compare injectate distribution and potential complications of retrobulbar and peribulbar injections in cat cadavers.Study designProspective randomized masked study.AnimalsTen cat cadavers (20 eyes).MethodsA dorsomedial retrobulbar injection (RB) of 1 mL of 0.5% bupivacaine and iopamidol (1:1) was performed in seven eyes. A dorsomedial peribulbar injection (PB‐1) of 4 mL of the same injectate was performed in seven eyes, and two peribulbar injections (PB‐2) of the same injectate, divided equally between the dorsomedial and ventrolateral regions (2 mL each) were performed in six eyes. Intraocular pressure (IOP) was measured before, immediately and 15 minutes after injection. Cadavers underwent computed tomography before and following injections. A radiologist scored injectate distribution within the intraconal space (none, moderate, or large) and around the optic nerve (degrees). An injection was defined as likely to provide adequate regional anesthesia if the volume of distribution of intraconal injectate was ‘large’ and it contacted over 270° of the optic nerve circumference.ResultsThe success rate (95% confidence interval) of RB, PB‐1, and PB‐2 injections was 71% (29.0–96.3%), 86% (42.1–99.6%), and 67% (22.3–95.7%), respectively. With all three techniques, IOP increased significantly after injection, but returned to baseline by 15 minutes following RB injection. No intraocular, intravascular, intrathecal, or intraneural injectate was observed.Conclusion and clinical relevanceThe single‐peribulbar injection technique may be superior to retrobulbar or double‐peribulbar injections, however, all techniques require further studies in live cats to determine safety and efficacy prior to clinical use.     

Pilot study of the ultrasonographic examination of the intact and transected medial glenohumeral ligament in dogs

Medial glenohumeral ligament injury is commonly reported during medial shoulder joint instability in dogs. Arthroscopy is considered the gold standard procedure, but it is invasive and requires distension of the joint. Ultrasonographic examination of the medial glenohumeral ligament has been studied as a possible, less invasive alternative to arthroscopy however it has not been considered a useful method of assessment due to the interference of the probe with the pectoral muscles. The aims of this prospective analytical randomized pilot study were to develop a standardized ultrasound protocol for visualizing the canine medial glenohumeral ligament and to compare goniometry and ultrasound findings in cadaver dogs with versus without transection of the medial glenohumeral ligament. Nine adult Beagle cadavers (18 shoulders) were used. The first six shoulders were used in a preliminary study to describe an ultrasound technique to identify the medial glenohumeral ligament. Arthroscopy was performed on the remaining 12 shoulders, with six randomly selected medial glenohumeral ligaments from these shoulders, transected during the procedure. Ultrasound examination was performed after each arthroscopic procedure by an ultrasonographer blinded to the patient group. Four medial glenohumeral ligaments (67%) were correctly identified during the preliminary study. Ultrasonographic examination failed to diagnose the transection of all six medial glenohumeral ligaments in the second part of the study. No difference was observed in the ligament thickness between the dogs with and without a transected medial glenohumeral ligament. Dogs with a transected medial glenohumeral ligament had a wider articular space compared to dogs without a transected ligament (P < 0.001), and an articular space wider than 8.2 mm was discriminatory of a transected medial glenohumeral ligament in all the shoulders. In conclusion, the medial glenohumeral ligament could be identified with a medial ultrasonographic approach of the shoulder and a wider articular space can be a sign of a medial shoulder joint instability. Further studies are needed to confirm these preliminary findings in living dogs, with and without shoulder instability.