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Polyetheretherketone (PEEK) can be processed with additive manufacturing, but post-processing is not well studied. This paper explores the grindability of extruded and 3D printed PEEK. Manual grinding was used because of its high relevance for finishing freeform parts. Grinding of extruded PEEK with a SiC belt with #400 grit size, a grinding speed of 3.6 or 5.6 m/s, and a target normal grinding force of 100 N achieved average surface roughness Ra from 0.93 to 0.99 μm. The study on grinding of 3D printed PEEK samples found appropriate parameters to achieve a low average surface roughness between Ra = 1 to 2 µm for 0° and 90° print angles (with a #400 SiC belt, 3.6 m/s grinding speed, and 75 N target normal grinding force). The 15° print angle sample suffered from surface delamination. This and further research improves post-processing repeatability and automation for 3D printed PEEK parts.

Gait analysis is a tool used to collect objective information in a research setting and when managing clinical patients to assess limb use and lameness in dogs and cats. Gait changes resulting from orthopedic and neurologic problems can be monitored over time to assess the progression of disease and/or response to therapy. Objective gait analysis measurements most commonly reflect the use of the whole limb but may not always represent joint-specific dysfunction or overall patient function. Subjective and objective gait evaluations include the comparison of findings from the left and right sides of the body and the comparison of findings from the patient to normal values.

Patient-centered care is increasingly advocated in human physical therapy and musculoskeletal rehabilitation to improve quality care and patient outcomes. Veterinary physical rehabilitation is an essential aspect of veterinary care and is inherently multidimensional. Historically, rehabilitation focused on physical aspects and omitted components critical to success, including the owner of the patient, the behavioral status of the patient, and anticipated future activities. These other components need to be considered to create genuine patient-centered care plans, which are needed to improve quality of care and patient outcomes. This article will outline a framework for veterinary patient-centered care focused on physical rehabilitation.

Hip dysplasia is one of the most common orthopedic conditions affecting dogs. Initially, laxity of the femur leads to subluxation, and subluxation can lead to an abnormal development or to progressive degeneration of the femoral head and dorsal acetabular rim. Osteoarthritis and its clinical impact progress over time. Changes to the femoral head and neck and the acetabulum and the impact on joint motion and pain vary widely among dogs. The rehabilitation of dogs with hip dysplasia includes rehabilitation therapy in dogs managed conservatively and the rehabilitation of dogs managed with surgery.

Hip dysplasia is among the most common orthopedic conditions affecting dogs. Joint laxity is responsible for abnormal development of the femoral head and acetabulum, leading to excessive wear of the articular cartilage. Wear leads to secondary osteoarthritis. Rehabilitation is either conservative or after surgical management. Conservative rehabilitation therapies are directed at decreasing pain, improving hip range of motion (ROM), and building or maintaining muscle mass. Postoperatively, rehabilitation focuses on decreasing postoperative pain and inflammation, improving comfort and limb use, and protecting the surgical site. Once the patient has healed, rehabilitation is directed at improving ROM and promoting muscle mass.

Many dogs compete in sports. The most popular sports include conformation, agility, disc dogs, dock diving, flyball, herding, tracking, rally obedience, canine freestyle, and racing short and long distances (eg, lure coursing, dog sledding). The purpose of this article is to review common dog sports, discuss the physical requirements of these sports, review common injuries seen in sporting dogs, and discuss physical rehabilitation after injury in sporting dogs.

Like in humans, measurements of musculoskeletal function in dogs collected by clinicians or owners can be grouped into specific instruments describing the level of disability of a joint or a limb. The repeatability of these instruments among clinicians and over time can be evaluated to confirm their reliability. Comparison to other methods will describe validity. Several outcome measure questionnaires such as the Comprehensive Brief Pain Inventory, the Canine Orthopedic Index, the Helsinki Chronic Pain Index, and the Liverpool Osteoarthritis in Dogs questionnaires have sufficient validation for use in many clinical situations.

Therapeutic exercises are the cornerstone of the rehabilitation programs of companion animals. Therapeutic exercises are used to improve active joint range of motion, to improve weight bearing and limb use, to build strength and muscle mass, and to increase conditioning (eg, endurance, speed). Each case is unique as chronicity, type of injury, patient signalment and temperament, owner compliance, and level of required functional recovery vary widely. Therapeutic exercises are also essential for partial return to work or performance and to learn to perform activities of daily living after injury or surgery.

A comprehensive physiotherapy plan for neurology patients manages pain, prevents secondary complications, and supports the health and function of musculoskeletal tissues during recovery. Neurologically impaired patients range in ability from complete immobility (tetraplegia/paraplegia), partial mobility (tetraparesis/paraparesis), mild ataxia, to pain only. Important considerations for the design of a physiotherapy program include access to the patient, level of staff support, and safety of staff, patient, and client during treatments. A thorough overview of the treatment plan and expected outcome should be discussed with the client at the onset of therapy and should be reviewed frequently, particularly as the patient's status changes.

Optimal function after injury, surgery, or in patients with chronic conditions requires adequate motion in joints, muscles, tendon, fascia, and skin. Range of motion and stretching exercises are commonly used in companion animal rehabilitation programs to maintain or improve motion of musculoskeletal tissues. Range of motion exercises and stretching prevent adhesions from forming, help scar tissue remodeling, may improve muscle tone, and prevent future injury from occurring. Stretching is used to avoid loss of motion or to regain lost joint motion. Stretching is done manually, using external coaptation, or using therapeutic exercises. Careful documentation of range of motion is necessary.

Exoprostheses are devices that are secured to incomplete limbs to enable locomotion. By comparison, orthoses are devices externally applied to support or protect an injured body part. Orthoses also can be used to control, guide, protect, limit motion of, or immobilize an extremity, a joint, or a body segment. Exoprostheses and orthoses are a growing aspect of the physical rehabilitation of companion animals. They require precise design and fabrication. Patients and owners must be trained to use the devices. Exoprostheses and orthoses can have a profound beneficial impact on the mobility and the quality of life of companion animals.

Cats have orthopedic problems, including osteoarthritis, fractures, and luxations that are positively impacted by physical rehabilitation. Most cats have an independent behavior that requires using a tactful approach to rehabilitation. Cats often do well with manual therapy and electrophysical modalities. Feline rehabilitation sessions may be shorter than canine rehabilitation sessions. Cats do best with therapeutic exercises when these exercises are linked to hunting, playing, or feeding.

Patients who have total joint arthroplasty have varying needs related to rehabilitation. In the short term, rehabilitation should be used in all dogs to identify high-risk patients and to minimize the likelihood of postoperative complications. Many patients undergoing total hip replacement recover uneventfully without needing long-term physiotherapy. All patients undergoing total knee replacement and total elbow replacement need rehabilitation to restore limb use and maximize their functional recovery. This article presents rehabilitation considerations for companion animals undergoing total hip replacement, total knee replacement, and total elbow replacement; postoperative complications and how to mitigate risks; and anticipated patient outcomes.

Open cellular structures fabricated in Ti6Al4V using the electron beam melting (EBM) process have been proposed for tissue scaffolds and low stiffness implants that approximate the properties of bone. The properties of these structures, regardless of cell geometry, have often been determined through compressive testing, and very few of these studies have investigated the flexural properties. For certain types of implants that are designed to fill very large segmental defects in appendicular bones, such as those used in limb sparing, compression testing does not provide the necessary insight into the complex loading states typical of bending. In this study, EBM-fabricated Ti6Al4V prismatic bars, populated with rhombic dodecahedron unit cells of various sizes and relative densities, were subjected to four-point flexure tests. While the results generally follow the power scaling models of Gibson and Ashby, the use of these models as a design tool is limited by machine resolution, particularly when producing structures with small pore sizes required for bone ingrowth.

This study aimed to define the rate of progression of radiographic osteoarthritis (OA) of the canine hip joint and to describe factors affecting this progression. Dogs that underwent unilateral total hip replacement (THR) were reviewed for the evaluation of radiographic appearance of the non‐operated hip joint over time. Standard extended ventrodorsal hip radiographs were taken preoperatively and postoperatively. All images were anonymized, randomized and scored using three different methods. The mean daily change between evaluations was calculated in each individual dog, and the effect of sex, age, body weight, open/closed status of the proximal femoral physis, preoperative severity of OA, time after surgery and their interactions, were investigated as potential influencing factors. After reviewing the medical records, 163 dogs (468 images) met the inclusion criteria. Consistent across the three scoring systems, radiographic progression of OA was greater in younger (open physis) and spayed female dogs. A subset of seven patients (4.3%) had a faster progression of OA and was considered outliers. No dog was rated as outlier by all three scoring systems. The rate of progression of radiographically assessed coxofemoral OA varies greatly, but is faster in younger, spayed female dogs. Unusually fast progression occasionally occurs.

To evaluate the effects of bolt torque, wire size, and component reuse on the ability to maintain wire tension in 3 external skeletal fixation systems.Design Biomechanical study.Yield strength in tension of 1.0-, 1.2-, 1.5-, and 1.6-mm-diameter wires, and yield strength in torque of Hofmann Small Bone Fixation (SBF) cannulated and slotted bolts and IMEX regular and miniature bolts were determined on a testing machine. The minimum bolt tightening torque needed to prevent wire slippage at clinically recommended wire tensions was determined. Components were tested 10 times, and loads at slippage were recorded.The IMEX system required a mean of 8 Nm of bolt tightening torque to maintain 900 N (1.6-mm wires). The SBF system required a mean of 3 Nm bolt torque to maintain 300 N (1.0-mm wires) and 5 Nm to maintain 600 N (1.2-mm wires). The SBF cannulated bolt required 9 Nm of torque to maintain 900 N (1.5-mm wires). The SBF slotted bolts could only maintain 800 N before yield. The IMEX miniature system required a mean bolt torque of 1.1 Nm to maintain 300 N. The cannulated and slotted bolts from both manufacturers failed to maintain 70% of initial wire tension after 7 and 4 uses, respectively.The IMEX systems and the SBF system using 1.0- and 1.2-mm wires could maintain clinically recommended wire tension safely. Only the IMEX system could maintain clinically recommended wire tension safely using 1.5- or 1.6-mm wires.The SBF system using 1.0- and 1.2-mm wires and the IMEX system using all wire sizes can maintain clinically relevant wire tension. The SBF system using 1.5-mm wires could not. Cannulated and slotted bolts should not be used more than 6 and 3 times, respectively. Nuts should not be reused.

To evaluate the treatment of a spontaneously occurring osteosarcoma in a dog by means of tumor resection and bone regeneration of a 12-cm defect using double bone transport.Case report.An 11 year-old client-owned German shepherd.After tumor resection, a preassambled Ilizarov frame was secured to the proximal tibia and to the tarso-metatarsal region. Two osteotomies were performed in the proximal metaphysis. The two bone segments were transfixed with 1.5-mm-diameter wires, each secured to a ring, and bone transport was performed until the distal segment reached the talar surface. Cisplatin was administered 14, 35, and 59 days after surgery.Bone regenerate was first visible radiographically 4 weeks after surgery. The frame was removed 162 days after surgery. The hock was protected with a plaster cast because the tarsal arthrodesis was not complete. The dog underwent tibiotarsal arthrodesis 201 days after osteosarcoma resection. The dog died of metastatic disease 239 days after the initial surgery.Even though this dog died of systemic metastases, local recurrence did not develop. Cisplatin chemotherapy did not appear to negatively affect bone regeneration.To our knowledge, the double transport technique has not been previously described in the veterinary literature. In this dog, this technique decreased the duration of treatment compared with a conventional single-segment transport technique.

To evaluate the prevalence of femoral intramedullary infarction after total hip arthroplasty (THA) and to determine whether any specific femoral morphology predisposes to bone infarction.Retrospective clinical study.All dogs from our hospital population undergoing THA between 1984 and 1997 with radiographic follow-up available at 1 year or more postoperatively.A case control study was conducted within the THA group to determine risk factors predisposing to femoral infarction after THA. Medical records and radiographs were reviewed. Data were collected on clinical parameters, femoral morphology, prosthesis, and bone changes. Radiographic diagnosis was confirmed using histopathology in 11 femora. Radiographs of 50 age-matched control dogs weighing more than 20 kg with coxofemoral degenerative joint disease were randomly chosen to determine the prevalence of bone infarction in nonoperated dogs.Ninety-one dogs with 110 THA were included in the study. Fifteen of the 110 femora with THA had radiographic evidence of infarction (14%). Infarction was not present in any femora in the control group. There was no significant difference in the prevalence of infarction between dogs that received cemented or uncemented prostheses. Clinical signs were not reported in any patient that developed femoral infarction. Young age ( P = .03) and a distance between the greater trochanter and nutrient foramen greater than 79 mm ( P = .008) predisposed dogs to femoral infarction. Over time, three infarcts decreased in size radiographically, five remained unchanged, and three expanded. An osteosarcoma developed at the site of a bone infarct in one dog. Femoral intramedullary infarction occurred in 15 of 110 THA. Young age at the time of THA and a greater distance between the greater trochanter and the nutrient foramen predisposed to infarction.Intramedullary infarction occurs after canine THA. These bone infarcts do not appear to cause clinical signs; however, they may present a diagnostic challenge. Malignant transformation could potentially result from medullary infarction.

To evaluate the long-term clinical and radiographic results of a canine uncemented porous-coated anatomic (PCA) total hip arthroplasty (THA).Prospective study of consecutive clinical patients using survival analysis.Forty-one dogs that underwent PCA THA; nine had bilateral PCA THA (50 prostheses).Gait observation, orthopedic examination, and radiographic assessment were conducted before THA, 6 months after THA, and yearly thereafter. A zonal analysis system was used to document osseous changes in the femur and the acetabulum. Acetabular cup and femoral stem subsidence and migration, femoral canal fill, and implant orientation were measured. Survival analysis of the procedure was conducted.Long-term follow-up was available for 37 dogs (46 prostheses). The median follow-up was 63 months. Limb function was normal for 37 limbs and abnormal for 9 limbs because of dislocation ( n= 3 ), lumbosacral disease ( n= 2 ), degenerative myelopathy ( n= 1 ), autoimmune disease ( n= 1 ), brain tumor ( n= 1 ), or osteosarcoma of the femur ( n= 1 ). All prosthetic stems and cups were fixed by bone ingrowth fixation. Osteolysis was not observed. Bone infarction occurred in five femoral canals (four dogs). The 6-year survival rate for the procedure was 87% (95% confidence interval, 72%-96%). Long-term fixation of the uncemented PCA acetabular cup and stem is successful in dogs, and long-term clinical function is excellent.

To report the occurrence of medullary bone infarction in both femoral canals after bilateral total hip arthroplasty (THA) and the subsequent unilateral development of an osteosarcoma at the site of bone infarction.Clinical report.An 8-month-old neutered male Samoyed dog.Serial physical and radiographic examinations performed at 1, 2, 3, and 5 years after THA. Bone biopsy specimens of the right distal femoral metaphysis were taken 5 years after THA, and a complete necropsy was performed at the time of euthanasia.Bilateral medullary bone infarction was visible in the femoral canals 1 year after THA and remained visible on subsequent evaluations. An osteosarcoma developed in the right distal femoral metaphysis at the site of infarction, 5 years after THA, and was found to have metastasized widely throughout the body.Bone infarction may occur in the femoral canal after canine THA.Bone infarction may be a predisposing factor for the development of osteosarcoma in the femora of dogs with THAs.

Circular external skeletal fixation (CEF) has been used in recent years to treat acute and chronic fractures and bone deformities, to stabilize joints while maintaining range of motion, and to perform arthrodeses and limb-sparing in dogs. Dr. llizarov defined the general principles and methods of CEF. This article reviews these principles. It also describes the indications, preoperative planning, surgical placement, postoperative management, clinical results, and complications of CEF used to treat fractures in dogs.

Elon College and North Carolina State University co-organized an animal rehabilitation elective course given to 12 MPT and 12 DVM students and conducted a post-course survey of the participants. Changes in perceptions of the field of animal rehabilitation, in perceived practice patterns, in the DVM students’ perception of the field of PT, and in knowledge of animal rehabilitation were present for 84–100% of students who answered the survey.