Page 375 - Canine Lameness

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20

Hip Region

Nina R. Kieves

Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA

20.1 Introduction and Common Differential Diagnoses

Lameness of the pelvic limb in the canine is often attributable to pathology associated with the
coxofemoral joint and surrounding structures. These can include osseous conditions affecting the
surrounding skeletal structures (pelvis and proximal femur) or the joint itself including, luxation,
developmental disease (hip dysplasia [HD]), and avascular necrosis of the femoral head. Muscle
conditions should also be included as differential diagnoses when investigating discomfort of the
hip region, including quadriceps contracture, gracilis and semitendinosus/semimembranosus
myopathy, and iliopsoas tendinopathy. The most commonly utilized tests include radiographs and
ultrasound. Figure 20.1 and Table 20.1 outline common differential diagnoses and diagnostic steps
for the hip region.

20.2 Normal Anatomy HIP REGION

The femoral head and acetabulum form the hip joint (Figure 20.2). Like the shoulder joint, its ball
and socket configuration allow it to function with a large range of motion – with the ability for signifi-
cant flexion, extension, as well as abduction and adduction. The primary joint stabilizers are com-
prised of the ligament of the head of the femur and the joint capsule. Secondary stabilizers include
the acetabular labrum, a fibrocartilaginous band that extends laterally from the dorsal acetabular rim
(DAR) and ventrally across the acetabular notch (i.e. the transverse acetabular ligament). Finally,
hydrostatic pressure is created by joint fluid and the periarticular muscles of the joint.
Periarticular muscles of the hip include the gluteal muscles (deep, middle, and superficial),
iliopsoas, quadratus femoris, gemelli, and the internal and external obturator muscles. The gluteal
muscles function to extend the hip joint, as well as internally rotate and abduct the femur. The
deep gluteal originates on the body of the ilium and the ischiatic spine extending caudally to insert
on the cranial aspect of the greater trochanter. It functions to extend, and abduct the hip, while also
medially rotating the femur. The largest of the gluteals, the middle, originates on the ilium and
inserts on the dorsal greater trochanter. The piriformis also contributes to hip extension with its
origin on the lateral surface of S3 and Cd1, inserting on the dorsal aspect of the greater trochanter

Canine Lameness, First Edition. Edited by Felix Michael Duerr.
© 2020 John Wiley & Sons, Inc. Published 2020 by John Wiley & Sons, Inc.
Companion website: www.wiley.com/go/duerr/lameness