Long-Term Radiographic Comparison of Tibial Plateau Leveling Osteotomy Versus Extracapsular Stabilization for Cranial Cruciate Ligament Rupture in the Dog

OBJECTIVE

Comparison of 2 methods of surgical management of cranial cruciate ligament (CCL) injury in large-breed dogs using a radiographic osteoarthrosis (OA) scoring system.

STUDY DESIGN

Retrospective study.

ANIMALS

Client-owned dogs (n=66).

METHODS

Radiographs were evaluated from dogs weighing >/=22.7 kg, with surgical management of CCL rupture using extracapsular repair (ECR) or tibial plateau leveling osteotomy (TPLO). Radiographs were taken immediately before surgery and >/=12 months later. An OA score was assigned to each set of radiographs taken at the preoperative and final examinations by evaluating 32 specific features of stifle OA. The difference between preoperative and final OA scores were subtracted and 2 final score categories of a change </=5 or >5 were created. A logistic regression model was used to evaluate the effect of right versus left pelvic limb, age, preoperative weight, postoperative weight, days from surgery until final radiographic recheck, cranial cruciate status at surgery, medial meniscus status at surgery, and ECR versus TPLO.

RESULTS

The ECR group had 27 stifles (22 dogs) and the TPLO group had 52 stifles (44 dogs). ECR dogs had a preoperative weight of 33.4+/-9.3 kg (range 22.7-54.1 kg) and a preoperative OA score of 13.0+/-8.4 (range 1-34) compared with TPLO dogs that had a preoperative weight of 38.9+/-9.1 kg (range 25-63.9 kg) and preoperative OA score of 15.9+/-8.4 (range 4-44). Postoperative weights for ECR and TPLO dogs were 33.6+/-9 kg (range 21.8-54.6 kg) and 39.4+/-10.1 kg (range 24-72 kg), respectively. Final OA scores were: ECR dogs, 26.3+/-10.8 (range, 10-54); TPLO dogs, 23.3+/-9.5 (range, 12-50). Dogs with a final change in OA score of >/=6 were 5.78 times more likely to have had ECR compared with those that had TPLO as stabilization procedure (odds ratio=5.78; Log-likelihood test P-value=.025). Other dependent variables were not significant.

CONCLUSIONS

Based on logistic regression analysis, dogs with larger OA score differences were 5.78 times more likely to have had ECR than TPLO.

CLINICAL RELEVANCE

Prospective, randomized surgical trials with pre-defined objective measures would be required to further evaluate the clinical importance of these preliminary findings which suggest that TPLO may help stabilize the cranial tibial thrust as originally proposed.

Relationship Between Age and Tibial Plateau Angle in Dogs With Cranial Cruciate Rupture

The pathogenesis of cranial cruciate ligament (CCL) rupture remains controversial, and its relationship to tibial plateau angle is unknown. In this study, the tibial plateau angle was measured in 200 large-breed dogs diagnosed with CCL rupture. Correlation analyses were performed to determine whether the age at the time of CCL rupture and the tibial plateau angle were related. While these two values were inversely correlated, the relationship was not strong enough to explain the frequency of CCL rupture in young, large-breed dogs. There was no statistically significant correlation between age at the time of CCL rupture and tibial plateau angle.

Evaluation of changes in vertical ground reaction forces as indicators of meniscal damage after transection of the cranial cruciate ligament in dogs

OBJECTIVE

To determine whether decreases in peak vertical force of the hind limb after transection of the cranial cruciate ligament (CrCL) would be indicative of medial meniscal damage in dogs.

ANIMALS

39 purpose-bred adult male Walker Hounds.

PROCEDURE

The right CrCL was transected arthroscopically. Force plate measurements of the right hind limb were made prior to and 2, 4, 10, and 18 weeks after transection of the CrCL. Only dogs with > or =10% decreases in peak vertical force after week 2 were considered to have potential meniscal damage. Dogs that did not have > or =10% decreases in peak vertical force at any time point after week 2 were assigned to group 1. Group 2 dogs had > or =10% decreases in peak vertical force from weeks 2 to 4 only. Group 3 and 4 dogs had > or =10% decreases in peak vertical force from weeks 4 to 10 only or from weeks 10 to 18 only, respectively. Damage to menisci and articular cartilage was graded at week 18, and grades for groups 2 to 4 were compared with those of group 1.

RESULTS

The percentage change in peak vertical force and impulse area was significantly different in groups 2 (n = 4), 3 (4), and 4 (4) at the end of each measurement period (weeks 4, 10, and 18, respectively) than in group 1 (27). The meniscal grade for groups 2 to 4 was significantly higher than for group 1. A > or =10% decrease in peak vertical force had sensitivity of 52% and accuracy of 72% for identifying dogs with moderate to severe medial meniscal damage.

CONCLUSIONS AND CLINICAL RELEVANCE

In dogs with transected or ruptured CrCLs, force plate analysis can detect acute exacerbation of lameness, which may be the result of secondary meniscal damage, and provide an objective noninvasive technique that delineates the temporal pattern of medial meniscal injury.

Feline cranial cruciate rupture: 17 cases and a review of the literature

Seventeen cases of feline cranial cruciate ligament rupture are presented. The cases are divided into two groups: those with traumatic multiligamentous damage, and those with isolated cranial cruciate ligament rupture without a history of trauma. The cats that had suffered cruciate ligament rupture were heavier than the general population of cats and there is evidence reported that this injury parallels the degenerative cranial cruciate ruptures seen in overweight small breed dogs. The limited literature on this subject is reviewed including approaches to treatment.

Treatment of chronic complete rupture of achilles tendon in three dogs with locking loop suture and own suture technique

The present case report describes three heavy dogs, Caucasian Shepherd breed, with chronic complete traumatic rupture of Achilles tendon, which was repaired with two types of sutures. Surgical treatment involved shortening the Achilles tendon, and using a locking loop suture technique and own suture technique with four buttons. Additionally, positional screw and cast supported the sutures. Twelve months postoperatively no discomfort and lameness were observed on clinical examination. This paper shows that treatment of chronic complete rupture of Achilles tendon with locking loop suture and own suture technique gives good results.

Sonographic assisted diagnosis and treatment of bilateral gastrocnemius tendon rupture in a Labrador retriever repaired with fascia lata and polypropylene mesh

This case report describes a four-year-old, eighty-five pound, male neutered Labrador retriever that was admitted with unilateral lameness and clinical findings consistent with a unilateral gostrocnemius tendon rupture. A prior history of trauma was not identified. Ultrasonagraphic evaluation revealed bilateral gastrocnemius tendon defects in which approximately 80% of the tendon was ruptured on the clinically normal side, yet mechanical function and anatomical length were not apparently altered. Bilateral surgical repair was performed utilizing primary tendon reconstruction, supported by fascia lata, autograft and polypropylene mesh. The repairs were protected with rigid costs for two weeks following surgery, and replaced with orthotics through the complete recovery period. Orthotics provided semi-rigid support and allowed removal for controlled intermittent physical therapy. This surgical repair technique, combined with orthotic support, allowed for early mobilization and good ultimate outcome for a complicated bilateral condition.

Unilateral nephrectomy as a treatment for renal trauma in a foal

A 2-day-old Warmblood colt foal was referred for evaluation of progressive abdominal distension and lethargy. Haemoperitoneum was diagnosed and a ventral midline laparotomy revealed capsular rupture, sub capsular haematoma and haemorrhage of the left kidney. Unilateral nephrectomy was performed and the foal recovered uneventfully, with no reported complications 1 year later.

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

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

[Rectal tears in the horse: a literature review]

Rectal tears are a relatively rare complication of rectal palpation, mating, or dystocia, and idiopathic rectal perforation is an incidental finding. Rectal tears can be classified according to a 3 or a 4-grade system. This article describes medical and surgical treatment for rectal tears.

[Rectal tears in the horse: two case reports]

Rectal tears occur incidentally and often have a poor prognosis. Early recognition of the problem and adequate therapy determine the outcome. The history, clinical examination, therapy, and outcome of two horses with grade IIIb and grade IV rectal tears are discussed.

[Rectal tears in the horse: malpractice or an unfortunate accident?]

Rectal tears are a relatively rare complication of rectal palpation, mating or dystocia, and idiopathic spontaneous occurrence of rectal perforation has also been described. Rectal tears have been classified in a three or a four-grade system. Immediate recognition of the fact that a tear has been made and prompt action will improve the horses chance of survival, and is the best defence of the veterinarian against legislation. There is no clear explanation why rectal tears sometimes occur. A questionnaire of the Netherlands Equine Veterinary Association revealed that rectal tears occurred both to inexperienced veterinarians and to very experienced colleagues, working with or without a probe for ultrasonography. In the opinion of the authors, the approach in the legislation of rectal tears should be that a rectal tear is only considered 'malpractice' if the veterinarian obviously acted carelessly. However, this would create the ridiculous situation that it seems better for the veterinarian-client relationship when the veterinarian confesses to 'careless' rectal palpation. This point needs further clarification, and perhaps an 'insurance of the horse for rectal palpation' will be the solution. Further, retrospectively over the last ten years, the problem is often not 'making a rectal tear', but 'lacking recognition of making a tear'. Whenever a rectal tear is suspected, the veterinarian must assess its severity, discuss the problem openly with the owner and apply appropriate treatment including referral.

Treatment of shoulder instability caused by medial glenohumeral ligament rupture with thermal capsulorrhaphy

A three-year-old, male springer spaniel had chronic left forelimb lameness with a medial glenohumeral ligament tear and articular cartilage damage diagnosed on arthroscopy. The animal failed to respond to conservative therapy of rest and an intra-articular injection of methylprednisolone. The use of thermal capsulorrhaphy using bipolar radiofrequency bought about a return of joint stability and resolution of the lameness.

An In Vitro Study to Determine the Effectiveness of a Patellar Ligament/Fascia Lata Graft and New Tibial Suture Anchor Points for Extracapsular Stabilization of the Cranial Cruciate Ligament-Deficient Stifle in the Dog

OBJECTIVE

(1) To determine whether an extracapsular patellar ligament/fascia lata graft would provide stability in the cranial cruciate ligament (CrCL)-deficient stifle comparable with that of the intact stifle. (2) To determine if different tibial anchor points would enhance stability of the CrCLdeficient stifle when compared with the standard fabellar-tibial suture (FTS) placement.

STUDY DESIGN

Experimental.

ANIMALS

Twenty-eight canine cadaver hind limbs.

METHODS

Stifles were mounted in a jig and tested between loads of -65 and 80 N. After testing the intact CrCL, 4 stabilization techniques were tested after CrCL transection: lateral graft technique (LGT) and 3 FTS with different tibial anchor points.

RESULTS

There were no significant differences in displacement between the LGT and standard FTS, between the LGT and the intact CrCL, or between the FTS and the intact CrCL, in either the Securos or the Screw-washer experiments. Stiffness of the intact CrCL was significantly greater than that of any stabilization technique and the cut CrCL. The standard FTS showed the least displacement of all suture stabilization techniques. Differences in stiffness were not significant between the suture stabilization techniques.

CONCLUSIONS

Securely anchored, the LGT results in a reduction in drawer motion similar to that of the intact CrCL and the standard FTS. Altering the tibial anchor point for the FTS does not improve stiffness or enhance stabilization of the CrCL-deficient stifle.

CLINICAL RELEVANCE

The LGT could be used for the treatment of CrCL ruptures in the dog. A clinical study is recommended.

Cranial Cruciate Ligament Pathophysiology in Dogs With Cruciate Disease: A Review

Cruciate disease is a common cause of chronic lameness in dogs. Midsubstance rupture of the cranial cruciate ligament (CCL) arises from progressive pathological failure, often under conditions of normal loading in adult dogs with CCL instability. A high risk of rupture is associated with inflammation of the synovium and adaptive or degenerative changes in the cells and matrix of the CCL. In contrast, CCL rupture in puppies is usually associated with traumatic injury and avulsion of the CCL from its sites of attachment.

Radiographic and Clinical Changes of the Tibial Tuberosity after Tibial Plateau Leveling Osteotomy

OBJECTIVE

To investigate radiographic changes of the tibial tuberosity after tibial plateau leveling osteotomy (TPLO) surgery and identify clinical findings and risk factors associated with such changes.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Hundred and eighty-six client-owned dogs (219 stifles) that had TPLO surgery.

METHODS

Patient data retrieved included radiographic changes of the tibial tuberosity during re-examination, age, body weight, whether unilateral or single-session bilateral surgery had been performed, location of the anti-rotational pin, approximate tibial tuberosity area, and approximate average tibial tuberosity width.

RESULTS

Fracture with resulting caudal displacement of the proximal tibial tuberosity (1.4%; 3 of 219) occurred less frequently than non-displaced tibial tuberosity fractures (7.3%; 16 of 219). Age, weight, average tibial tuberosity width, location of the anti-rotational pin, and single session bilateral surgery were identified as risks factors for non-displaced fracture. Weight divided by the square of the average tibial tuberosity width may be a stronger risk factor than either weight or average tibial tuberosity width alone.

CONCLUSIONS

Dogs undergoing single session bilateral TPLO surgery are at greater risk for developing non-displaced tibial tuberosity fractures. The non-displaced tibial tuberosity fracture does not appear to adversely affect outcome or lead to tibial tuberosity avulsion. Significant risk factors for fracture of the proximal tibial tuberosity with caudal displacement were not identified.

CLINICAL RELEVANCE

Factors including age, weight, tibial tuberosity thickness, and conditions that may enhance strain on the tibial tuberosity, such as single-session bilateral procedures, may increase risk of fracture.

Assessing the efficacy of perioperative oral carprofen after cranial cruciate surgery using noninvasive, objective pressure platform gait analysis

OBJECTIVE

To document, using pressure platform gait analysis, the effect of perioperative oral carprofen on limb function and pain after cranial cruciate ligament surgery in dogs.

STUDY DESIGN

Blinded, prospective clinical investigation.

ANIMALS

Twenty dogs with naturally occurring unilateral cranial cruciate disease.

PROCEDURE

Physiologic indices, subjective pain scoring, and pressure platform gait analyses were performed before and 24, 48, and 72 hours after surgery. Correlations were assessed between methods of evaluation and the data was compared across treatment groups.

RESULTS

No strong correlations were noted between physiologic data, subjective scoring systems, or gait analysis data at a walk or stance. Although average measures of limb function were nearly twice as large in dogs treated with carprofen, no significant differences between groups over time were identified. No significant differences were noted in any other measure of pain or limb function. Power analysis of peak vertical force at a walk indicated that significant difference would have been detected had the number of dogs in each group been increased to 35.

CONCLUSION

When limb function was assessed with pressure platform gait analysis no statistical difference was noted between groups with respect to PVF and VI at a walk or stance, although average ground reaction forces for dogs in the carprofen group were greater than the traditional pain management group at all time points.

CLINICAL RELEVANCE

Oral carprofen appears to provide some benefit for the treatment of postoperative orthopedic pain.

Influence of Limb Positioning and Measurement Method on the Magnitude of the Tibial Plateau Angle

OBJECTIVE

To evaluate the effect of limb positioning and measurement technique on the magnitude of the radiographically determined tibial plateau angle (R-TPA).

STUDY DESIGN

In vitro study, R-TPA was determined by 6 blinded observers and image measurement software.

ANIMALS

Five canine cadaver hind limbs.

METHODS

The legs were positioned on a custom-made positioning device simulating a radiographic tabletop technique in lateral recumbency. True lateral positioning was defined by superimposition of femoral and tibial condyles on the radiographic projection. Radiographs were taken while the specimens were relocated in a proximal, distal, caudal, and cranial direction with respect to the radiographic beam. For each specimen, 25 different radiographic views were obtained and 6 blinded observers determined the radiographic TPA using 2 different methods. The conventional method used precise anatomic landmarks to determine the tibial plateau. To simulate osteoarthritic changes complicating identification of these landmarks, the tangential method estimated the tibial plateau as the tangent to the central portion of the tibial plateau. After periarticular soft tissue dissection the anatomic tibial plateau angle (A-TPA) was determined. The A-TPA and the R-TPA were compared.

RESULTS

The R-TPA significantly decreased as limb position with respect to the X-ray beam changed from cranial proximal to caudal distal. The maximal mean radiographic R-TPA difference was 3.6 degrees with the first and 5.7 degrees with the second method. Regardless of the method used there was no significant difference between A-TPA and R-TPA in the true lateral position. In the peripheral positions, however, significant differences between anatomic and radiographic TPA were seen.

CONCLUSIONS

Limb positioning influenced the radiographic appearance of the tibial plateau and the magnitude of the measured TPA. Cranial and proximal positioning of the limb relative to the X-ray beam leads to overestimation whereas caudal and distal positioning leads to underestimation of the TPA.

CLINICAL RELEVANCE

True lateral positioning of the tibia defined by superimposition of the femoral and tibial condyles should be used for accurate TPA determination before tibial plateau leveling osteotomy.

Gallbladder mucocele in dogs: 30 cases (2000–2002)

OBJECTIVE

To determine long-term outcome of dogs with gallbladder mucocele.

DESIGN

Retrospective study.

ANIMALS

30 dogs with gallbladder mucocele, including 23 that underwent cholecystectomy.

PROCEDURE

Medical records were reviewed for signalment, history, and clinical, ultrasonographic, and surgical findings. Follow-up information was obtained for all dogs that survived the perioperative hospitalization period.

RESULTS

23 dogs had signs of systemic illness; 7 had no clinical signs. Median values for serum activities of alanine aminotransferase and alkaline phosphatase, serum total bilirubin concentration, and total WBC count were significantly higher among dogs with gallbladder rupture than among dogs without rupture. Sensitivity of sonography for detection of rupture was 85.7%. Overall perioperative mortality rate for dogs that underwent cholecystectomy was 21.7%; mortality rate was not significantly greater for dogs with rupture. Aerobic bacteria were isolated from the bile or gallbladder wall in 8.7% of dogs. All 18 dogs discharged from the hospital had complete resolution of clinical signs. In dogs that underwent in-hospital reexamination, serum liver enzyme activities were significantly decreased, compared with preoperative activities. Persistent increases in serum activities of 1 or more liver enzymes were detected in 9 of 12 dogs; 6 of 12 dogs had persistent abnormalities in hepatic echogenicity. Mean follow-up period was 13.9 months.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that cholecystectomy is an effective treatment for gallbladder mucocele. Although perioperative mortality rate is high, prognosis after discharge from the hospital is excellent. Rupture of the gallbladder warrants emergency surgical intervention but does not preclude a positive outcome.

Sonographic diagnosis of a presumed ureteral tear in a horse

A 14-year-old thoroughbred gelding was presented for the evaluation of acute abdominal pain. Rectally, there was a soft fluctuant painful swelling dorsal to the bladder and to the right of the midline. The creatinine concentration of the peritoneal fluid was 15 mg/dl. Transrectal ultrasonographic examination of the urinary tract revealed a large collection of fluid dissecting from the pelvic portion of the right ureter ventrally through the right side of the bladder wall and into the retroperitoneal space, and a thickened right ureter and bladder wall at the level of the trigone. Cystoscopically there was moderate hemorrhage within the wall of the bladder. Ultrasonography revealed air within the retroperitoneal fluid collection after ureteral catheterization, confirming the preliminary diagnosis of a tear in the right ureter. The gelding was treated medically. After 48 h of hospitalization, nuclear scintigraphy revealed normal clearance from both kidneys and no apparent leakage from the right ureter. The ureteral tear and urinoma were monitored using transrectal ultrasound until resolution. The horse was successfully returned to racing. This case establishes the value of diagngstic ultrasound in the diagnosis and monitoring of a traumatic ureteral tear in a horse.

Laparoscopic Repair of a Small Intestinal Mesenteric Rent in a Broodmare

OBJECTIVES

To describe standing laparoscopic repair of mesoduodenal rent inaccessible by ventral median celiotomy.

STUDY DESIGN

Clinical case report.

SAMPLE POPULATION

A 6-year-old Thoroughbred broodmare with a right displacement of the dorsal colon and small intestinal incarceration in a mesoduodenal rent.

METHODS

Two days after correction of a right dorsal displacement of the ascending colon, small intestinal incarceration, and partial closure of mesoduodenal rent, standing left and right flank laparoscopy was used to explore the abdomen to identify the mesoduodenal defect. The mesenteric rent was repaired from right flank portals by approximation with hemostatic clips.

RESULTS

Approximation of the mesoduodenal rent was achieved with laparoscopic clips. No further complications or signs of abdominal pain occurred over the following year.

CONCLUSIONS

Mesenteric rents in the mesoduodenum can be repaired by laparoscopic techniques in the standing horse.

CLINICAL RELEVANCE

Use of laparoscopic techniques in the standing horse should be considered for mesoduodenal rents that are not accessible form a ventral median celiotomy.

Results of Single-Session Bilateral Tibial Plateau Leveling Osteotomies as a Treatment for Bilaterally Ruptured Cranial Cruciate Ligaments in Dogs: 25 Cases (2000–2001)

The records of 25 dogs with bilaterally ruptured cranial cruciate ligaments (CrCL) treated with single-session bilateral tibial plateau leveling osteotomies (TPLOs) were reviewed. The mean age and body weight at presentation were 4.9 years and 36.1 kg, respectively. Minor complications occurred in five dogs. Good or excellent function occurred in 19 of 25 dogs at a mean of 6.9 weeks postoperatively. Owner evaluation revealed that the 88% of dogs had good or excellent function at an average of 14.3 months postoperatively. This study demonstrated that single-session bilateral TPLOs are an effective treatment for bilaterally ruptured CrCLs with minimal morbidity and complications.

Complete patellar ligament replacement using a fascia lata autograft in a dog

A novel technique for the repair of a chronically lacerated patellar ligament in a pet greyhound is described. The injury had been sustained traumatically, and a previous surgical repair had proved unsuccessful. On further surgical investigation, identification of the ruptured ligament ends was not possible. A double fascia lata graft was employed to reconstruct the lateral and medial portions of the ligament. This repair was augmented with 27 kg monofilament nylon anchored through tunnels from the proximal tibia to the patella and quadriceps tendon. A concurrent skin deficit was managed with a superficial epigastric axial pattern flap. To the authors' knowledge, only one previous case requiring complete patellar ligament replacement has been documented in the veterinary literature. This report details a simplified surgical technique which may have advantages over the previously described technique.

Dorsal tarsal instability in three racing greyhounds

Rupture of the dorsal ligaments of the tarsus in the greyhound is a rare racing injury. This case report describes dorsal tarsal instability in three greyhounds. A stumble and somersault were observed in two cases and were thought to have caused the injury. Previous reports advocate partial intertarsal arthrodesis as the preferred treatment for dorsal instability of the proximal intertarsal joint, but not all dogs returned to successful racing. In these three cases, stability was restored by the insertion of a wire tension band anchored to two bone screws, allowing the development of periarticular fibrosis. The dogs raced again with no loss of form.

Use of the proximal portion of the tibia for measurement of the tibial plateau angle in dogs

OBJECTIVE

To determine whether the canine tibial plateau angle (TPA) can be accurately measured from lateral radiographic views of the stifle joint that include only the proximal portion of the tibia.

SAMPLE POPULATION

282 lateral radiographic views of the stifle joint from 128 dogs.

PROCEDURE

236 radiographs were obtained from 102 dogs with no stifle joint disease, and 46 were obtained from 26 dogs with cranial cruciate ligament rupture. Radiographs were digitized. Tibial plateau angles were determined by measuring the angle between the intersection of the tibial plateau slope line and perpendiculars to 4 tibial axes. The gold standard TPA was based on a reference axis that used the entire length of the tibia and was determined by the line connecting the midpoint of the tibial intercondylar eminence and the center of the talus. Tibial plateau angle1, TPA2, and TPA3 were based on tibial axes that were determined by use of only the proximal portion of the tibia.

RESULTS

TPA determined on the basis of the shortest proximal reference axis (TPA1) was not accurate. However, as the length of the reference axis increased, reliability of the TPAs obtained from proximal reference axes improved, and their correlations with the gold standard TPA increased (r = 0.78, 0.86, and 0.92 for TPA1, TPA2, and TPA3, respectively). Equations obtained by regression analysis allowed estimation of the gold standard TPA with some degree of accuracy.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of a proximal reference axis to calculate TPA may be an alternative to a calculation based on the full-length axis.

Evaluation of ligament fibroblast viability in ruptured cranial cruciate ligament of dogs

OBJECTIVE

To determine fibroblast viability, assess development of apoptosis, and evaluate tissue hypoxia via histochemical, in-situ hybridization, or immunohistochemical staining in ruptured and intact cranial cruciate ligaments (CCLs) of dogs.

ANIMALS

32 dogs with ruptured CCLs, and 8 aged and 19 young dogs with intact CCLs.

PROCEDURE

Markers of cell viability (lactate dehydrogenase [LDH]), apoptosis (terminal deoxynucleatidyl transferase-mediated deoxyuridine triphosphate-nick end labeling [TUNEL] method), and hypoxia (hypoxia-inducible factor-1alpha [HIF-1alpha] monoclonal antibody) were applied to CCL specimens; positive cells were assessed objectively (LDH) and subjectively (TUNEL and HIF-1alpha) in the main axial tissue component (core) and synovial intima and subintima (epiligamentous tissue).

RESULTS

Viable fibroblasts were seen in all intact and ruptured CCLs. More nonviable cells were found in the core regions of ruptured CCLs and intact CCLs of young dogs than in the epiligamentous regions. Number of nonviable cells in the core region of ruptured CCLs was greater than that in intact CCLs of young and aged dogs, whereas the number in the epiligamentous region was similar in all specimens. The TUNEL and HIF-1alpha staining was only found in the epiligamentous region of ruptured CCLs.

CONCLUSIONS AND CLINICAL RELEVANCE

Ruptured CCLs contained a high number of nonviable cells but not a great number of apoptotic cells. Repair processes in the epiligamentous region of the CCL include a metabolic response to hypoxia, suggesting that necrosis of ligament fibroblasts and transformation of surviving cells to a spheroid phenotype may be a response to hypoxia cause by microinjury or inadequate blood flow.

Complications with and owner assessment of the outcome of tibial plateau leveling osteotomy for treatment of cranial cruciate ligament rupture in dogs: 193 cases (1997-2001)

OBJECTIVE

To identify complications associated with tibial plateau leveling osteotomy (TPLO) for treatment of cranial cruciate ligament rupture in dogs and assess owner perceptions of outcome.

DESIGN

Retrospective study.

ANIMALS

193 dogs that underwent unilateral or bilateral TPLO (253 TPLOs total) between November 1997 and March 2001.

PROCEDURE

Complications associated with the surgical procedure were recorded. A questionnaire was sent to owners of all dogs to assess their perceptions of outcome.

RESULTS

Complications were identified in 47 of the 193 (24.4%) dogs and in association with 52 of the 253 (20.6%) TPLOs. Dogs that underwent bilateral TPLOs during a single anesthetic episode had a higher complication rate than did dogs that underwent unilateral TPLO and dogs that underwent bilateral TPLOs during separate anesthetic episodes. Body weight, surgery time, whether a meniscal release or meniscectomy was performed, and extent of cruciate ligament damage were not associated with whether complications occurred. One hundred forty-one of 151 (93%) owners who responded to the questionnaire were satisfied with the outcome of the surgery. Assessments of outcome were not significantly different between owners of dogs that had complications and owners of dogs that did not.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that complications developed in approximately 25% of dogs undergoing TPLO for treatment of a cranial cruciate ligament injury but that most complications responded to appropriate treatment, and development of complications did not affect owner assessments of outcome. There was a higher incidence of complications when bilateral TPLOs were performed during a single anesthetic episode.

Are the material properties and matrix composition of equine flexor and extensor tendons determined by their functions?

REASONS FOR PERFORMING STUDY

Injury to the superficial digital flexor tendon (SDFT) is common in competition horses. The SDFT contributes to locomotory efficiency by storing energy; such tendons have low safety margins. Tendons which merely position the limb, including the opposing common digital extensor tendon (CDET), are rarely injured. The current failure of strategies to prevent or effectively treat injury to the SDFT indicates the importance of understanding how it differs from tendons which are not injury-prone.

HYPOTHESIS

That the structural and material properties and matrix composition of the SDFT and CDET differ, reflecting their specific functional requirements in vivo.

METHODS

Forelimb tendons were harvested from 26 mature horses and loaded to failure prior to matrix composition analysis of specimens.

RESULTS

The SDFT had a significantly higher cross-sectional area, structural stiffness, failure load and failure strain and a lower elastic modulus than the CDET (P < 0.0001).

CONCLUSIONS

The SDFT has conflicting requirements for strength and elasticity; although as a whole it is a stiffer structure than the CDET, differences in the matrix molecular composition including water and total sulphated glycosaminoglycan contents allow it to remain more elastic as a material.

POTENTIAL RELEVANCE

Further information on how the two tendons attain these different properties may be of use in the development of prevention and treatment strategies for SDFT rupture.

Management of obstructive urolithiasis and concurrent urethral rupture in a goat

A 4-month-old, male castrated Alpine White goat presented to the University of Guelph, Veterinary Teaching Hospital, with urolithiasis and a ruptured urethra. A tube cystostomy was performed using an indwelling Foley catheter. Postoperatively, the goat remained in good health, and was discharged with the cystostomy catheter in situ. Five weeks following surgery, the goat was noted to pass urine through its urethra. Seven weeks following surgery, the catheter became dislodged and the goat was observed to urinate normally. Six months following surgery, the goat was apparently healthy and urinating normally. Tube cystostomy may be a useful therapeutic option in the management of small ruminants with obstructive urolithiasis with concurrent rupture of the urethra, especially for cases in which treatment cost is a limiting factor.

Histologic changes in ruptured canine cranial cruciate ligament

OBJECTIVES

To determine changes to the cells and collagenous and amorphous extracellular matrix (ECM) structure in ruptured canine cranial cruciate ligaments (CCL).

STUDY DESIGN

Prospective clinical study.

ANIMALS

CCL specimens obtained from 29 dogs with ruptured CCL and 6 young dogs with intact CCL.

METHODS

Ligament fibroblast number density and phenotype were determined in the core and epiligamentous regions. ECM birefringence and crimp structure in the core region were also studied.

RESULTS

Loss of fibroblasts from the core region of ruptured CCL was seen (P <.001), whereas, in the epiligamentous region, cell number densities were similar in ruptured and intact CCL (P =.7). In ruptured CCL, numbers of typical ligament fibroblasts (fusiform and ovoid cells) were decreased, and numbers of cells exhibiting chondroid transformation (spheroid cells) were increased in the core region (P <.001). Expansion of the volume of the epiligamentous region was also seen, although bridging scar tissue was not seen between the ends of ruptured CCL. The structure of the ECM collagen in the core region was extensively disrupted in ruptured CCL. This was, in part, because of decreased birefringence and elongation of the crimp in the remaining collagen fibers when compared with intact CCL (P <.01).

CONCLUSIONS

Extensive alterations to the cell populations and collagenous ECM structure were seen in ruptured CCL. Although a proliferative epiligamentous repair response was seen in ruptured CCL, there was a lack of any bridging scar between the ruptured ends of the CCL.

CLINICAL RELEVANCE

The cellular and ECM changes in ruptured CCL that we have described appear to result from the cumulative effects of remodeling and adaptation to mechanical loading and microinjury. Treatment of early cruciate disease in dogs will need to inhibit or reverse these progressive changes to CCL tissue, which are directly associated with partial or complete structural failure of the CCL under conditions of normal activity.

[Traumatic rupture of the common bile duct in a dog]

Extrahepatic biliary tract rupture only rarely occur secondary to blunt or sharp trauma to the abdomen. Clinical symptoms result from chemical peritonitis and are unspecific. Recognition most often is delayed from several days to weeks, when patients suffer from ascites, icterus, dehydration and apathy. Surgical therapy depends of the site of laceration. In the present case, a dog with bile peritonitis was presented two weeks after being hit by a car. Explorative celiotomy revealed a rupture of the common bile duct. A cholecystojejunostomy was performed.

Kinematic analysis of the hind limb during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament rupture

OBJECTIVE

To determine hip, stifle, and tarsal joint ranges of motion (ROM) and angular velocities during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament (CCL) rupture.

DESIGN

Prospective clinical study.

ANIMALS

13 healthy dogs and 7 dogs with CCL rupture.

PROCEDURE

Dogs with CCL rupture were enrolled in a postoperative aquatic rehabilitation program and evaluated 21 to 35 days after surgery. Dogs were filmed while swimming in a pool and while walking at a fast (1.3 m/s) or slow (0.9 m/s) pace on a treadmill. Maximal angles of extension and flexion, ROM, and angular velocities were calculated.

RESULTS

In healthy dogs, swimming resulted in a significantly greater ROM in the hip joint than did walking, but in dogs with CCL rupture, ROM of the hip joint did not vary with swimming versus walking. For dogs in both groups, swimming resulted in significantly greater ROM of the stifle and tarsal joints than did walking, primarily because of greater joint flexion. Stifle joint ROM was significantly lower in dogs with CCL rupture than in healthy dogs, regardless of whether dogs were swimming or walking.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that following surgical management of a ruptured CCL in dogs, swimming resulted in greater ROM of the stifle and tarsal joints than did walking. This suggests that if ROM is a factor in the rate or extent of return to function in these dogs, then aquatic rehabilitation would likely result in a better overall outcome than walking alone.

Effect of perioperative oral carprofen on postoperative pain in dogs undergoing surgery for stabilization of ruptured cranial cruciate ligaments

A randomized, placebo-controlled, parallel study was conducted to investigate the effectiveness of oral carprofen for the control of postoperative pain in dogs undergoing knee surgery for stabilization of ruptured cranial cruciate ligaments. Dogs were randomly assigned to treatment with carprofen (n = 10) or placebo (n = 9). Pain was assessed at 1, 2, 4, 6, 24, and 48 hours and 10 and 21 days postoperatively. Eight of 10 dogs treated with carprofen and five of nine dogs treated with placebo were given at least one dose of morphine as rescue therapy. The mean relative dose of morphine given at 1 hour (P =.01) and 24 hours (P =.02) after surgery was greater for dogs treated with carprofen than for dogs given a placebo. There were no significant postoperative differences in cortisol levels or any measured variable. It appears that the scoring system used was not sensitive enough to detect differences in pain between a known analgesic and a placebo.

Use of ultrasound to diagnose diaphragmatic rupture in dogs and cats

Twenty-one cats and six dogs that presented to a first-opinion clinic with signs of dyspnea and muffled cardiac auscultation received ultrasonography to look for signs of diaphragmatic rupture. The presence or absence of diaphragmatic rupture was subsequently determined on the basis of unequivocal radiographic signs, surgical findings, or necropsy. Consistent findings in animals with diaphragmatic rupture were irregular or asymmetric cranial aspect of the liver and abdominal viscera in the thorax. Accuracy of ultrasonography was 25/27 (93%). One false-negative result occurred in a cat with a chronic diaphragmatic rupture in which adhesions between the liver and lung simulated the appearance of an intact diaphragm. One false-positive result occurred in a dog with an abscess involving the left lung and pleural cavity, which was misinterpreted as the stomach. The results of this study support use of ultrasonography in animals with suspected diaphragmatic rupture.

Surgical and postoperative complications associated with tibial plateau leveling osteotomy in dogs with cranial cruciate ligament rupture: 397 cases (1998-2001)

OBJECTIVE

To identify surgical and postoperative complications of tibial plateau leveling osteotomy (TPLO) in dogs with rupture of the cranial cruciate ligament (CCL) and compare their incidence with those reported in the literature for other commonly performed CCL stabilization procedures.

DESIGN

Retrospective study.

ANIMALS

346 dogs undergoing 397 TPLO procedures.

PROCEDURE

Medical records of dogs undergoing 563 consecutive TPLO procedures were reviewed. Complications were recorded and assigned to groups on the basis of the period during which the complication was observed.

RESULTS

397 TPLOs met the criteria for inclusion in the study. Complications (n = 136) were recorded in 113 of the 397 (28%) procedures. Multiple complications developed in 10 dogs. In 19 dogs, a second surgery was performed to manage complications. Development of a complication after surgery was not associated with age or body weight of the dog, tibial plateau angle prior to stifle joint surgery, or experience of the surgeon. Factors significantly associated with complications were breed and performance of an arthrotomy concomitantly with TPLO.

CONCLUSIONS AND CLINICAL RELEVANCE

TPLO was associated with development of numerous complications, some of which required surgical correction. Most complications resolved with nonsurgical treatment. Several complications were unique to the TPLO procedure because of the surgical technique and implants required. Although TPLO was associated with a greater number of complications than other CCL stabilization methods, the incidence of major complications was similar.

Laparoscopic repair of ruptured urinary bladder in a stallion

A 12-year-old stallion was evaluated because of pollakiuria; endoscopy of the urinary tract during general anesthesia revealed that the urinary bladder was intact. After recovery, the stallion developed clinical and biochemical signs of bladder rupture, which was confirmed by endoscopy. Cystoplasty in adult stallions represents a unique surgical dilemma; the large distance between the incision site and the bladder necessitates the repair be accomplished under maximum tension with minimal exposure. Because traditional surgical approaches through ventral midline or paramedian incisions provide limited access and viewing, laparoscopy was used to provide a definitive diagnosis, good viewing, easy access, tension-free dissection, and a secure repair. Lack of surgical complications and postoperative discomfort, rapid and uncomplicated healing, and patient-client satisfaction make laparoscopic cystoplasty the preferred method for surgical repair of ruptured urinary bladder in adult stallions.

Rupture of the cranial pubic tendon in the cat

Seven cats with rupture of the cranial pubic tendon (CPT) were presented to the authors between 1992 and 2001. The causal aetiology was unclear in each case. Diagnosis was made on physical examination (five animals) or surgical exploration (two animals). Concurrent injuries were present in four cats, including injury to the urinary tract and musculoskeletal system. All ruptures were surgically explored and primary repair of the CPT rupture was performed in five cats. Repair was not possible in two cats, and follow-up examination showed that scar tissue had apparently formed to support the deficit. All cats were asymptomatic at follow-up examination. The prognosis for CPT rupture in the cat is favourable.

Comparison of tibial plateau angle between clinically normal Greyhounds and Labrador Retrievers with and without rupture of the cranial cruciate ligament

OBJECTIVE

To compare tibial plateau angle (TPA) between Greyhounds without damage to the cranial cruciate ligaments and Labrador Retrievers with and without damage to the cranial cruciate ligaments.

DESIGN

Clinical study.

ANIMALS

87 client-owned dogs and 15 research colony Greyhounds.

PROCEDURE

Standing position, horizontal-beam radiography was performed on Greyhounds and unaffected Labrador Retrievers to determine standing TPA. Lateral radiography of the stifle joint was performed on all dogs to determine traditional TPA. Age and body weight were recorded for unaffected and affected Labrador Retrievers.

RESULTS

Greyhounds had mean standing TPA of 1.56 degrees and mean traditional TPA of 22.50 degrees. Unaffected Labrador Retrievers had mean standing TPA of 3.52 degrees and traditional TPA of 27.97 degrees. Affected Labrador Retrievers had mean traditional TPA of 25.55 degrees. No significant difference was found in mean standing TPA between Greyhounds and unaffected Labrador Retrievers. Standing TPAs in Greyhounds and unaffected Labrador Retrievers were not significantly different from a plane drawn parallel to the ground. Significant differences in traditional TPAs were detected among all 3 groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Greyhounds had mean traditional TPA of 22.50 degrees; similar angles should be considered normal for dogs. Although affected Labrador Retrievers had mean traditional TPA that was significantly greater than that of Greyhounds, the steepest TPA was found in unaffected Labrador Retrievers. Because Greyhounds and unaffected Labrador Retrievers had similar standing TPAs, we conclude that although TPA may be associated with damage to the cruciate ligaments, many dogs with a steep TPA do not develop cruciate ligament disease.

Caudal proximal tibial deformity and cranial cruciate ligament rupture in small-breed dogs

Eight dogs presented with chronic hindlimb lameness associated with cranial cruciate ligament rupture. Seven were small terriers. A caudal deformity of the proximal tibial shaft, originating at the proximal tibial physis, and an excessive caudal slope of the tibial plateau were present bilaterally in all dogs. The deformity was thought to be responsible for the cranial cruciate ligament failure and poor response to conservative management. Tibial plateau angles were in excess of 26 degrees in all dogs. The lameness was bilateral in three dogs. There was complete cranial cruciate ligament rupture in seven stifles and partial rupture in four. There were no meniscal injuries. Surgical correction resulted in a significant improvement (P<0.0001) in all dogs, with a mean follow-up of 12 months (range three to 24 months). There were no complications.

Do regional variations in flexor tendons predispose to site-specific injuries?

Partial rupture occurs most often to the superficial digital flexor tendon (SDFT) of the forelimb at the mid-metacarpal level. In this study, we tested the hypothesis that the mid-metacarpal region of the SDFT has the smallest cross sectional area (CSA) and a similar collagen content to other regions and, therefore, represents a weak point in the tendon. The SDFT was collected from the forelimbs of 9 horses. Each tendon was marked at 7 different levels from the origin of the accessory ligament to the phalangeal region. The CSA, water content and collagen content was measured at each level. The mid-metacarpal level had a significantly smaller CSA than the most proximal and distal levels measured and a significantly higher dry matter content than proximal levels. However, the total amount of collagen present in the mid-metacarpal section was not significantly less than other regions except for the most distal sections. The results of this study suggest that the mid-metacarpal region of the SDFT, although smaller in CSA, is not significantly weaker than the proximal end and manica flexoria region of the tendon. Therefore, other factors such as hypoxia and/or hyperthermia may be responsible for site-specific tendon lesions in the SDFT.

Evaluation of tartrate-resistant acid phosphatase and cathepsin K in ruptured cranial cruciate ligaments in dogs

OBJECTIVE

To determine localization of tartrate-resistant acid phosphatase (TRAP) and cathepsin K in ruptured and healthy cranial cruciate ligaments (CCL) in dogs.

ANIMALS

30 dogs with ruptured CCL, 8 aged dogs without ruptured CCL, and 9 young dogs without ruptured CCL.

PROCEDURE

The CCL was examined histologically and cells containing TRAP and cathepsin K were identified histochemically and immunohistochemically, respectively.

RESULTS

Cathepsin K and TRAP were detected within the same cells, principally within the epiligamentous region and to a lesser extent in the core region of ruptured CCL. Numbers of cells containing TRAP and cathepsin K were significantly greater in ruptured CCL, compared with CCL from young or aged dogs, and numbers of such cells were greater in CCL from aged dogs, compared with those of young dogs. In aged dogs, small numbers of cells containing TRAP and cathepsin K were seen in intact CCL associated with ligament fascicles in which there was chondroid transformation of ligament fibroblasts and disruption of the extracellular matrix.

CONCLUSIONS AND CLINICAL RELEVANCE

Ruptured CCL contain greater numbers of cells with the proteinases TRAP and cathepsin K than CCL from healthy, young, or aged dogs. Results suggest that cell-signaling pathways that regulate expression of these proteinases may form part of the mechanism that leads to upregulation of collagenolytic ligament remodeling and progressive structural failure of the CCL over time.

Spontaneous hepatic rupture in six cats with systemic amyloidosis

Spontaneous hepatic rupture, secondary to the accumulation of hepatic amyloid, was diagnosed in six cats over a two-year period. Previous reports of feline hepatic amyloidosis have documented clusters of cases from breeding catteries. Most affected cats have been Siamese or a related breed and the disease is generally regarded as familial. In contrast, the cases presented here were sporadic, with relatives and other cats in the household not clinically affected. They included a Devon rex, a breed not previously reported with this condition, and a domestic shorthair. Clinical signs in three of these cases had, prior to referral, been misinterpreted as resulting from blunt trauma, immune-mediated haemolysis or a coagulopathy. Antemortem diagnostic features, including new data on the value of hepatic ultrasonography and fine-needle aspirate cytology, are reported. These cases illustrate how the course of this disease can vary between individuals and that, despite the dramatic underlying pathology, hepatic amyloidosis can present a diagnostic challenge and should be suspected in any young adult cat with consistent clinical signs, irrespective of breed or environment.