Darryl L. Millis

Effects of partial immersion in water on vertical ground reaction forces and weight distribution in dogs

OBJECTIVE To assess the impact of partial immersion in water on vertical ground reaction force (vGRF) and vGRF distribution in dogs. ANIMALS 10 healthy adult dogs. PROCEDURES Weight placed on each limb of each dog was measured 3 times (1 scale/limb). Dogs were then immersed in water to the level of the tarsal, stifle, and hip joints, and vGRFs were measured. Coefficients of variation for triplicate measurements were calculated. Mixed-effects ANOVAs were used to compare the vGRF for thoracic versus pelvic limbs and the vGRF at various immersion levels as well as the vGRF distributions among limbs at various immersion levels. RESULTS Mean±SD vGRF before immersion was 249±34 N. It was significantly decreased by 9% after immersion to the tarsal joints (227±32 N), by 15% after immersion to the stifle joints (212±21 N), and by 62% after immersion to the hip joints (96±20 N). The vGRFs were significantly higher for the thoracic limbs than for the pelvic limbs before immersion and at all immersion levels. Dogs placed 64% of their weight on the thoracic limbs before immersion. That ratio did not differ significantly after immersion to the tarsus (64%) or stifle (63%) joints, but was significantly larger after immersion to the hip joints (71%). CONCLUSIONS AND CLINICAL RELEVANCE vGRF decreased as the depth of immersion increased. The thoracic limb-to-pelvic limb vGRF ratio was unchanged in dogs after immersion to the tarsal or stifle joints, but it increased after immersion to the hip joints.

Kinematic analysis of the pelvic limbs of healthy dogs during stair and decline slope walking.

OBJECTIVES To evaluate range of motion (ROM) of the pelvic limb in healthy dogs descending stairs compared with decline slope walking. METHODS Reflective spheres were placed on the skin over the joints of the right pelvic limb of seven adult, hound-type dogs with no clinical signs of orthopaedic or neurologic disease. Five trials of stair and ramp descent of each dog were recorded using four 60 Hz digital infrared cameras. Two-dimensional kinematic data were collected as dogs walked down stairs and on a continuous decline of equivalent slope. Maximum and minimum joint angles and ROM were calculated for the coxofemoral, femorotibial and tibiotarsal joints. RESULTS Stair descent resulted in significantly greater femorotibial flexion and tibiotarsal flexion and extension compared with continuous slope descent. Significantly greater ROM was achieved in the coxofemoral, femorotibial and tibiotarsal joints during stair descent. CLINICAL SIGNIFICANCE Compared with a continuous slope, stair descent achieves greater ROM in the pelvic limbs of dogs. Stair descent may be a useful therapeutic exercise to improve ROM in dogs with musculoskeletal disease of the pelvic limb, and ramp descent may be easier for dogs with limited motion of pelvic limb joints.

Bone- and Non–Bone-Derived Growth Factors and Effects on Bone Healing

In the future, it may be possible to manipulate the fracture site with exogenous growth factors to allow successful union of the bone ends without additional surgery. The complex interaction of growth factors, the timing of their appearance and disappearance at the wound site, and the concentrations necessary to achieve specific effects must be studied more thoroughly. For growth factors to find widespread clinical use, there must be evidence that healing is enhanced. It may be difficult to enhance the healing of fresh fractures in normal animals, and it may also be difficult to demonstrate the healing of nonunion fractures. Because of the great variability in fractures of clinical patients, studies designed to determine the effect of growth factors on bone healing must be carefully designed with appropriate attention given to randomizing patients based on the risk of delayed healing and other patient characteristics.

Kinematics of stair ascent in healthy dogs

OBJECTIVE The purpose of the study was to evaluate the kinematic characteristics of pelvic limb joints in orthopaedically normal dogs during stair ascent. DESIGN Prospective study. PROCEDURE Eight hound-type dogs were fitted with reflective spheres at palpable landmarks, including the tuber ischium, greater trochanter, cranial dorsal iliac spine, lateral epicondyle of the femur, lateral malleolus, and the base of the fifth metatarsal bone. Each dog was walked up a set of custom made stairs consisting of four steps and then trotted across a level test space. Data were recorded for the right and left pelvic limbs during ascent. Maximum and minimum joint angles and total joint motion were calculated for all joints and evaluated statistically. RESULTS Pelvic limb joints had a greater total joint excursion during stair ascent. There was greater extension of the coxofemoral and tibiotarsal joints during ascent, whereas the stifle joint had less extension. Maximum flexion of the stifle and tarsal joints was significantly greater in stair ascent. There was not any significant difference between the right and left limbs. CONCLUSIONS All joints of the pelvic limb undergo a greater joint motion to ascend stairs.

Therapeutic Laser in Veterinary Medicine

Laser therapy is an increasingly studied modality that can be a valuable tool for veterinary practitioners. Mechanisms of action have been studied and identified for the reduction of pain and inflammation and healing of tissue. Understanding the basics of light penetration into tissue allows evaluation of the correct dosage to deliver for the appropriate condition, and for a particular patient based on physical properties. New applications are being studied for some of the most challenging health conditions and this field will continue to grow. Additional clinical studies are still needed and collaboration is encouraged for all practitioners using this technology.

Evidence for canine rehabilitation and physical therapy.

This article reviews some important studies regarding canine physical rehabilitation. Bones, cartilage, muscles, ligaments, and tendons undergo atrophy if loading is decreased. Knowledge of the changes that occur with immobilization and the time course of events helps in the development of a rehabilitation program to improve tissue integrity. Outcome assessment instruments are clinically useful indicators of patient progress and the success of rehabilitation programs. A number of physical modalities are used in canine rehabilitation, although there are relatively few canine-specific studies. Rehabilitation has specific benefits in the treatment of various orthopedic and neurologic conditions.

Exercises in canine physical rehabilitation: range of motion of the forelimb during stair and ramp ascent

OBJECTIVES To evaluate overall joint range of motion of the forelimb in healthy dogs ascending stairs compared with incline slope walking. METHODS Normal canine forelimb kinematics (range of motion, flexion and extension) were compared during ascent of stairs or a ramp, and compared to unimpeded trotting on a flat surface. Eight adult dogs with no evidence of orthopaedic or neurological lameness were assessed using a 2-dimensional kinematic system as they walked up a custom built ramp and stairs. RESULTS In healthy dogs, ramp and stair ascent consistently had greater range of motion compared to trotting on a flat surface, and ramp ascent had significantly greater range of motion compared to stair ascent (P<0·05). Shoulder flexion and extension, elbow extension and carpal flexion were all significantly greater while ascending the ramp compared to stairs. Shoulder extension on the flat was significantly greater than while ascending stairs. CLINICAL SIGNIFICANCE When planning physical rehabilitation exercises following injury to the forelimb, stair and ramp ascent may be considered, as both augment range of motion of joints. Ramp ascent provides the greatest increase in range of motion of forelimb joints.

Bone and Lean Tissue Changes Following Cranial Cruciate Ligament Transection and Stifle Stabilization

Following cranial cruciate ligament transection and extracapsular stabilization, dual-energy X-ray absorptiometry was used to analyze bone mineral content and lean tissue mass in the surgical and nonsurgical legs (n=14) at 0, 2, 4, and 8 weeks, and to evaluate bone mineral content and bone mineral density (BMD) of the proximal, mid-, and distal tibia of both the surgical and nonsurgical legs (n=15) at 0, 5, and 10 weeks. There was significant loss of bone mineral content and lean tissue in the surgical leg compared to the nonsurgical leg. Significant loss in bone mineral content and BMD was detected in the tibia of the surgical leg and was most pronounced in the metaphyseal region.

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.

Rehabilitation and physical therapy for selected orthopedic conditions in veterinary patients.

A specific diagnosis is needed to perform optimal rehabilitation of orthopedic problems. A well-planned rehabilitation program is important for orthopedic patients when surgical repairs are mechanically weak (eg, when repairing fractures in skeletally immature patients or when repairing tendons or ligaments). Joint immobilization is sometimes used to protect weak surgical repairs. The duration of immobilization should be minimized, particularly in situations with potential loss of joint motion. Evidence-based information regarding specific modalities and techniques for rehabilitation of injured dogs and cats is generally lacking. The choice of modalities and techniques must be based on common sense, knowledge of rehabilitation techniques, and clinical experience.