Defining the rate of, and factors influencing, radiographic progression of osteoarthritis of the canine hip joint

Abstract

Background 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. Methods 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. Results 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. Conclusion The rate of progression of radiographically assessed coxofemoral OA varies greatly, but is faster in younger, spayed female dogs. Unusually fast progression occasionally occurs.

Prevalence of radiographic appendicular osteoarthritis and associated clinical signs in young dogs

“…To minimize ionizing radiation exposure, where appropriate, radiographs were centered on the midpoint of the limb or spinal segment to reduce the number of individual exposures used. A subjective radiographic OA numerical rating scale where 0 = no radiographic abnormalities identified and 10 = most severe radiographic OA, was assigned to each joint based on presence of radiographic changes and their overall severity based on previously reported information 23 . Radiologic features considered indicative of presence of appendicular OA were osteophytes, enthesophytes, sclerosis, subchondral bone erosions and cysts.…”

Prevalence of Radiographic Appendicular Osteoarthritis and Associated Clinical Signs in Young Dogs

“…To minimize ionizing radiation exposure, where appropriate, radiographs were centered on the midpoint of the limb or spinal segment to reduce the number of individual exposures used. A subjective radiographic OA numerical rating scale where 0 = no radiographic abnormalities identi ed and 10 = most severe radiographic OA, was assigned to each joint based on presence of radiographic changes and their overall severity based on previously reported information 22 . Radiologic features considered indicative of presence of appendicular OA were osteophytes, enthesophytes, sclerosis, subchondral bone erosions and cysts.…”

“…Radiographs were assessed independently using a DICOM viewer (Horos ver. 3.3.6) by two observers, a board-certi ed small animal veterinary surgeon (BDXL) and a veterinarian experienced in evaluating canine OA (ME) 22 .…”

Evaluation of subchondral bone cysts in canine elbows with radiographic osteoarthritis secondary to elbow dysplasia

“…[12][13][14] The radiographic hallmarks of OA in the dog are osteophytosis, subchondral sclerosis, and joint effusion, [15][16][17][18][19] and they are assessed in several clinical and experimental scoring systems. 9,[20][21][22][23][24][25][26] Interestingly, subchondral bone cysts (SBCs), which are an imaging hallmark of human, equine, and murine OA, are not a well established feature of OA in dogs, with their presence only sporadically reported. 15,[27][28][29] In human OA, SBCs, also known as pseudocysts or geodes, are defined as small radiolucent defects in the subchondral bone surrounded by sclerotic margins.…”

“…However, computed tomography (CT) is becoming increasingly commonplace due to its increased specificity and sensitivity in comparison with radiography 12–14 . The radiographic hallmarks of OA in the dog are osteophytosis, subchondral sclerosis, and joint effusion, 15–19 and they are assessed in several clinical and experimental scoring systems 9,20–26 . Interestingly, subchondral bone cysts (SBCs), which are an imaging hallmark of human, equine, and murine OA, are not a well established feature of OA in dogs, with their presence only sporadically reported 15,27–29 .…”