Ground reaction force analysis of unilateral coxofemoral denervation for the treatment of canine hip dysplasia.

Coxofemoral denervation has success rates of 90-96% reported retrospectively for palliative treatment of hip dysplasia. The aim of this study was to objectively evaluate ground reaction forces (GRF) in dysplastic dogs after unilateral denervation. Unilateral coxofemoral denervation was performed by means of a previously reported technique on 10 dogs with asymmetric gait. GRF were measured at zero, one and three months. Statistical analysis was performed using repeated measures analysis of variance and paired t-tests, with p< or =0.05. There was a lack of significant difference in mean peak vertical force (PVF) or vertical impulse (VI) in the operated limb (TX) over time. For the unoperated limb (UnTX), mean PVF and VI significantly decreased over time. The dogs were significantly more lame in the TX limb initially and at one month, however, there was no significant difference between limbs by three months. In the UnTX limb, 40% of dogs decreased PVF by >5%, by three months. Over time, there was no significant difference in mean average rise or mean average fall for TX or UnTX limbs. Between limbs, mean rise in the TX limb was significantly less at zero months, but not at one or three months. Decreased compensatory load shifting to the UnTX limb due to procedural efficacy could explain decreases in the UnTX limb. Worsening disease could also explain decreases in the UnTX limb, and may indicate a protective effect denoted by a lack of change in the TX limb. Longer follow-up would be required in improved dogs in order to document continued efficacy.

Digital measurement of radiographic tibial plateau angle. A comparison to measurement on printed digital images.

Pre-operative digital radiographs from 50 dogs undergoing a tibial plateau leveling osteotomy were evaluated. Tibial plateau angles were measured directly on printed films and measured on digital images using two different commercial DICOM viewers. The radiographs were scored for osteoarthritis and positioning. Using pooled results, the mean TPA from the digital images employing Web1000 (26.47 degrees +/- 3.90) was significantly higher then the mean TPA using film radiographs (25.41 degrees +/- 3.51), or IQ-View Pro (25.48 degrees +/- 3.89). There was not a significant difference between mean TPA using radiographs or IQ-view. Digital TPA measurement using built-in angle calipers in the clinical setting is a valid technique compared to measurements from film radiographs, and produces reproducible results. However, before changing to digital measurements, the chosen software programme should be validated against measurements using film radiographs to determine the magnitude of differences.

Evaluation of the lame patient.

Competence in evaluating lameness is vital for the veterinary practitioner. This skill is becoming even more important with the increasing popularity of large-breed dogs and the corresponding increase in the number of developmental orthopedic problems seen on a day-to-day basis. A proper physical examination of the lame patient is essential to the management of the case. This article reviews the initial evaluation of the lame veterinary patient without dwelling on the specific differential diagnoses and corresponding treatments.

Evaluation of a method for experimental induction of osteoarthritis of the hip joints in dogs.

OBJECTIVE: To evaluate a method for experimental induction of osteoarthritis in the hip joints of dogs. ANIMALS: 12 mixed-breed dogs. PROCEDURE: A unilateral triple pelvic osteotomy was performed. In 6 dogs, the iliac osteotomy was repaired with 45 degrees of internal rotation, reducing coverage of the femoral head by the acetabulum. In the other 6 dogs, the fragments were repaired in anatomic alignment. Radiography, force plate evaluations, and subjective lameness evaluations were performed before and after surgery. Dogs were euthanatized 7 months after surgery, and samples of cartilage and joint capsule were examined histologically. RESULTS: Subjective lameness scores, radiographic appearance of the hip joints, and Norberg angles were not significantly different between groups; however, force plate evaluations did reveal significant differences in vertical ground reaction forces. Femoral head coverage was significantly decreased with rotation of the acetabulum. Mild inflammatory changes were discernible in the joint capsule and articular cartilage of some dogs in both groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that 45 degrees internal rotation of the acetabulum does not consistently induce biologically important osteoarthritic changes in the hip joints of dogs.

Comparison of stance time and velocity as control variables in force plate analysis of dogs.

OBJECTIVE: To investigate effects of the use of stance time or velocity as control variables on ground reaction forces in lame dogs. ANIMALS: 12 dogs with pelvic osteotomies. PROCEDURE: Data for ground reaction forces were obtained preoperatively and at 2, 4, 6, 8, 12, 16, 20, 24, and 28 weeks postoperatively, using velocity and stance time as control variables. Ground reaction forces obtained were compared between the 2 methods of data collection, as were velocities and stance times of the trials. RESULTS: Significant differences in ground reaction forces were not found between the use of velocity or stance time as a control variable at any time. Also, significant differences in stance times or velocities were not found between the 2 methods of data collection. Greatest variation in stance time and velocity was found during periods of greatest lameness. CONCLUSIONS AND CLINICAL RELEVANCE: Use of stance time as a control variable in force plate analysis does not lead to significantly different results from use of velocity as a control variable, indicating that either method may be used in force plate analysis of dogs.