The Hip Joint

K. Mohan Iyer

• Publisher: Jenny Stanford Publishing
• Year: 2016
• Print ISBN: 9789814745147
• eBook ISBN: 9781315341019
• Edition: 1
• Topic: Medicine
• Subtopic: Surgery & Surgical Medicine

For centuries, orthopaedic surgeons have been managing the pain, limp, and gait disturbance that develop in association with various traumas and diseases of the hip joint. The hip is a ball-and-socket joint that has a good range of movement, but it is stable and rarely dislocates, even after high-impact trauma, and can withstand repeated motion and a fair amount of wear and tear. However, despite its durability, it is not indestructible. With age and use, the cartilage can wear down or become damaged. Overuse of muscles and tendons of the hip, for example, in athletes, leads to hip pain due to muscle strain or tendonitis. Other factors that can cause pain and lead to progressive arthritic changes include the abnormal anatomy a person is born with, conditions that develop during the growth and development of bones, and trauma as well as wear and tear due to ageing. The diagnosis and management of hip injuries have evolved substantially with advances in hip arthroscopy and diagnostic tools such as MRI and new, minimally invasive techniques.

This book provides a detailed account of the hip joint's anatomy and biomechanics and serves as a practical guide for the diagnosis and treatment of hip diseases and injuries at all ages. The book covers recent trends in orthopaedic surgery of the hip joint, including the latest advances in revision total hip arthroplasty (THA), computer-assisted navigation for THA, resurfacing of the hip joint, neoplastic conditions around the hip, and indications, complications, and outcomes of hip arthroscopy. The chapters are written by experts who have contributed greatly to the understanding of problems of the hip joint. The book will be appreciated by undergraduate and postgraduate students, experienced hip surgeons, medical doctors, and practicing consultants in orthopaedics.

Chapter 1

Embryology and Anatomy of the Hip Joint

K. Mohan Iyer^†

Royal Free Hampstead NHS Trust, Royal Free Hospital, Pond Street, London NW3 2QG, UK
[email protected]

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The Hip Joint
Edited by K. Mohan Iyer
Copyright © 2017 Pan Stanford Publishing Pte. Ltd.
ISBN 978-981-4745-14-7 (Hardcover), 978-981-4745-15-4 (eBook)
www.panstanford.com

1.1 Embryology of the Hip Joint

Bone, cartilage, muscle, and connective tissue all arise from the primitive mesoderm. All the elements of the hip joint differentiate from a single mass of mesoderm, and in 50 to 60 postovulation days, it resembles its final form. The joint cavity appears after 45 to 50 days in the central portion of the interzone and spreads peripherally around the head of the femur, which is initially crossed by cellular strands. The concavity of the acetabulum appears at an early age and the congruence of the hip is established as soon as the joint is formed. Hip formation begins in the seventh week of gestation. It develops as a cartilaginous analogue at 4 to 6 weeks of birth. At around 7 weeks, a cleft develops in the precartilagenous cells, which thereafter develops into the femoral head and the acetabulum, and this development is complete by 11 weeks to form the hip joint. The femoral head is completely enclosed by the acetabular cartilage, and in the later stages of gestation, the femoral head grows more rapidly than the acetabular cartilage, so much so that at birth, the femoral head is less than 50% covered. The acetabulum is most shallow and lax, thereby facilitating the delivery process, and the hip is uncontained in extension and adduction, reflecting on the hip shallowness. Several weeks after birth, the acetabular cartilage grows faster than the femoral head, which allows more coverage. If the head of the femur is not positioned properly in the acetabulum, or if movement of the femoral head is reduced, normal bone modelling and a shallow hip socket may develop. By 11 weeks of gestation, hip formation is complete. The pelvis and femoral head are composed primarily of cartilage rather than bone. Hence the normal factors such as shallowness and laxity are the main initial factors for the development of developmental dysplasia of the hip (DDH). The first critical period for hip dislocation occurs at 12 weeks’ gestation when the foetal lower limbs rotate nearly 90° medially, so that the knees point anteriorly and the hips assume their normal position in the pelvis.

The hip joint is a ball-and-socket joint, with the articular surface of the head of the femur being reciprocally curved nearly congruent, which fits into the cup-shaped fossa of the acetabulum, with its centre lying about 2 cm below the middle third of the inguinal ligament. The head of the femur is completely covered with the articular surface, except for a small roughened area at its centre, where the ligament of the head is attached. The articular surface of the acetabulum is an incomplete ring, which is deficient below and opposite the acetabular notch, which lodges a pad of fat covered with a synovial membrane. The depth of the acetabulum in increased by a fibrocartilaginous rim called the acetabular labrum.

Hence the ligamentous structures of the hip joint are (1) a fibrous capsule, (2) the acetabular labrum (3) the ligament of the head of the femur, and (4) the iliofemoral, ischiofemoral, pubofemoral, and transverse acetabular ligaments.

1.1.1 The Fibrous Capsule

The fibrous capsule is strong and dense, which surrounds the neck of the femur anteriorly to the trochanteric line and behind to the neck just 1 cm above the trochanteric crest. From its attachments to the front of the femoral neck are many fibres called retinacula reflected upwards as longitudinal bands, which supply blood vessels to the head and neck of the femur. The longitudinal fibres are greatest in number at the upper and front parts of the capsule and are reinforced in the front by the iliofemoral ligament. The articular capsule is also strengthened by the pubofemoral and ischiofemoral ligaments. The synovial membrane is extensive and covers the neck, which is contained within the joint capsule.

1.1.2 The Acetabular Labrum

The acetabular labrum is a fibrocartilaginous rim attached to the margin of the acetabulum, and hence deepens the cavity of the acetabulum, and bridges the acetabular notch like the transverse ligament, forming a complete circle.

1.1.3 Ligament of the Head of the Femur

The ligament of the head of the femur is spiral in nature, from its attachment to the ischium below and behind the acetabulum when it is directed upwards and laterally over the back of the neck of the femur.

1.1.4 The Iliofemoral Ligament

The iliofemoral ligament is triangular in shape and stronger and lies in front of the joint intimately blended with the capsule. The pubofemoral ligament is also triangular and intimately blended with the capsule. The ischiofemoral ligament is spiral in nature at the back of the joint. The transverse ligament is in reality a part of the acetabular labrum.

1.2 Anatomical Relations of the Hip Joint

• Anteriorly, the fibres of the pectineus lie between the femoral vein and the capsule. Lateral to the pectineus is the tendon of the psoas major and lateral to it is the iliacus. Laterally is the femoral artery which lies on the psoas tendon, and the femoral nerve lies deeply in the groove between it and the iliacus. Still laterally is the straight head of the rectus femoris.

• Superiorly the reflected head of the rectus femoris lies intimately with the capsule.

• Inferiorly, the lateral fibres of the pectineus lies on the capsule and more posteriorly the obturator externus crosses obliquely to gain the posterior aspect of the joint.

• Posteriorly, the capsule is covered by the tendon of the obturator externus, which separates it from the quaratus femoris. Above that the tendon of the obturator internus and the two gamelli are in contact with the joint and lie between it and the sciatic nerve.

The arterial supply to the joint comes from the obturator, medial circumflex femoral along with the superior and inferior gluteal arteries.

The nerve supply to the hip joint comes from the femoral, directly or indirectly from its muscular branches, the obturator, or the accessory obturator nerve to the quadratus femoris and superior gluteal.

1.3 Movements of the Hip

The active movements of the hip joint are flexion-extension, adduction-abduction, or a combination of the above, namely circumduction, medial rotation, and lateral rotation.

Muscles producing these movements:

• Flexion: Psoas major and iliacus, assisted by pectineus, rectus femoris, and sartorius. Adductors, mainly the adductor longus may help in the early stages. The primary flexor is the iliopsoas, which is supplied by the femoral nerve (L1, L2, and L3), while the secondary flexor is the rectus femoris.

• Extension: Gluteus maximus and hamstrings. The primary extensor is the gluteus maximus, which is supplied by S1, the inferior gluteal nerve, while the secondary extensor is the hamstrings.

• Abduction: Gluteus medius or minimus, assisted by tensor fascia latae and sartorius. The primary abductor is the gluteus medius, which is supplied by L5, the superior gluteal nerve. The secondary abductor is the gluteus minimus.

• Adduction: Adductors longus, brevis, and magnus, assisted by pectineus and gracilis. The primary adductor is the adductor longus, which is supplied by the obturator nerves L2, L3, and L4, while the secondary adductors are the adductor brevis and adductor magnus, pectineus and gracilis.

• Medial rotation: Tensor fascia latae and anterior fibres of the gluteus maximus and medius.

• Lateral rotation: The obturator muscles, gemelli and quadratus femoris, assisted by piriformis, gluteus maximus and sartorius.

1.4 Applied Anatomy

• The iliofemoral ligament is rarely torn in dislocations of the hip joint, which fact is taken into account when reducing these uncommon dislocations by making it to act as a fulcrum to a lever, in which the long arm is the body of the femur and the short arm is the neck of the bone.

• Congenital dislocation is more commonly seen in the hip joint than in any other articulation, when the displacement is usually seen on the gluteal surface of the ilium, as the upper part of the acetabulum is deficient.

• When manipulating the sacroiliac joint, advantage is taken of the fact that the iliofemoral and ischiofemoral ligaments are usually taut in extension of the hip joint, when forcible attempts to produce hyperextension of the hip joint along with forward pressure of the iliac crest may result in movement of the sacroiliac joint.

• Preservation of piriformis during exposure of the hip joint via a posterior approach may result in a lower rate of dislocation following total hip arthroplasty.

• Certain points of interest in applied anatomy can be found in Refs. [1, 2, 3 and 4].

1.5 Blood Supply of the Hip Joint

The blood supply of the hip joint is from branches of three arteries which cross the hip joint, namely the femoral, the obturator, and the profunda femoris arteries. The elaborate detailed description was initially documented by Joseph Trueta [5].

Branches from these arteries supply the hip joint by way of retinacular vessels which go in a direction towards the centre of the hip joint. Hence any interruption of these results in the proximal part of the hip joint losing its vascularity, a term coine...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Foreword
• Preface
• Acknowledgements
• 1 Embryology and Anatomy of the Hip Joint
• 2 Biomechanics of the Hip Joint
• 3 Clinical Examination of the Hip Joint
• 4 Imaging of the Hip Joint
• 5 Disorders of the Hip in Children and Adolescents
• 6 Injuries around the Hip Joint, Including Periprosthetic Fractures
• 7 The Adult Hip and Its Disorders
• 8 Total Hip Arthroplasty
• 9 Girdlestone Arthroplasty
• 10 Osteotomies around the Hip Joint
• 11 Hip Resurfacing
• 12 Minimally Invasive Total Hip Replacement
• 13 Computer Navigation in Hip Arthroplasty
• 14 Neoplastic Conditions around the Hip
• 15 Arthroscopy of the Hip
• Index