Ligamentum teres. This strong ligament inserts into the fovea centralis of the femoral head along with important nutrient vessels.

Acetabular labrum. This incomplete fibrocartilaginous ring contributes to hip joint stability. It may undergo traumatic or degenerative tearing leading to hip pain, instability and mechanical symptoms such as clicking.

Gluteus medius tendon. This is an important abductor and lateral rotator of the hip that inserts upon the lateral and posterior facets of the greater trochanter.

Iliotibial band (ITB) or tract. This long dense fascial band is a continuation of the tensor fascia lata muscle. It may undergo friction with resultant thickening and inflammation as it passes over the greater trochanter, producing painful, proximal ITB friction syndrome.

Transverse part of the ilio-femoral ligament. The ilio-femoral ligament is a thickening of the joint capsule and is the strongest of the three hip ligaments, the other two being the ischio-femoral and pubo-femoral ligaments.

Right sacroiliac joint.

Right anterior inferior iliac spine.

Right superior pubic ramus.

Left obturator foramen.

Contrast in bladder.

Lesser tuberosity of the right humerus. The subscapularis tendon attaches here. This may rarely become avulsed during hyper-external rotation injury due to traction by the subscapularis tendon insertion.

Greater tuberosity of the right humerus. This forms the bony footprint for the supraspinatus tendon.

Right acromion. The coraco-acromial ligament attaches from here to the coracoid process, forming a roof over the shoulder joint. Bony enthesopathy of this ligament may contribute to subacromial impingement of the supraspinatus tendon and is implicated as a causative factor in the evolution of rotator cuff tears.

Right acromio-clavicular joint. This narrow synovial joint commonly undergoes degenerative changes but may also develop erosions in inflammatory arthropathy.

The antero-inferior glenoid rim. This bears the attachment of the anterior band of the inferior glenohumeral ligament, which is an important static stabilizer of the glenohumeral joint. This region may be fractured during anterior glenohumeral dislocation, producing a bony Bankart lesion.

Medial collateral ligament (MCL). This important ligament arises from the medial femoral condyle and inserts on the medial tibial diaphysis and resists valgus stress of the knee.

Posterior cruciate ligament. This strong ligament arises from the lateral surface of the medial femoral condyle and inserts on the posterior intercondylar fossa of the tibia. It is a central stabilizer of the knee resisting posterior tibial translation.

Iliotibial band (ITB). This long structure originates from the fascia of the iliotibial tract and inserts on Gerdy's tubercle on the antero-lateral tibia. Distally it may undergo repetitive friction over the lateral border of the lateral femoral condyle to produce painful distal ITB friction syndrome.

Articular cartilage of medial tibial plateau. This thick layer of hyaline cartilage is composed of four zones or layers. During the evolution of osteoarthrosis the chondral layers may undergo softening, fibrillation, fissures and progressive thinning, ultimately resulting in full-thickness cartilage loss and sclerosis of the exposed sub-chondral bone.

Discoid lateral meniscus. The lateral meniscus is broad, spanning the whole width of the lateral tibio-femoral compartment. This normal variant, if present, is frequently bilateral and should be examined carefully due to the high incidence of degenerative tears with this variant.

Lesser trochanter of the right femur. The iliopsoas tendon attaches here. This is a powerful flexor of the hip.

Greater trochanter of the right femur. Gluteus medius and gluteus minimis attach here. These tendons act to perform hip abduction and lateral rotation. They can produce avulsion fractures of the greater trochanter in trauma.

Left L5 transverse process. The ilio-lumbar ligament attaches here. Traction of this ligament in pelvic trauma can cause an avulsion fracture of the transverse process. It also acts as an anatomical landmark on MRI for identifying the L5 vertebral body.

Pubic symphysis. It is a secondary cartilaginous joint.

Left inferior pubic ramus. Adductor magnus and adductor brevis attach here acting to adduct the hip.

Left L5 nerve. At the level of the L5/S1 disc, the L5 nerve has already left the neural exit foramen. It may become compromised by a far lateral L5 disc herniation in this position.

Nucleus pulposus of L5/S1 disc. This soft central component of the disc is surrounded by the tough outer annulus fibrosus. Annular defects result in herniation of the nucleus pulposus referred to as protrusions or extrusions, based upon their morphology. On T2-weighted images the nucleus pulposus is of high signal and the annulus fibrosus is of low signal intensity.

Left lamina of L5 vertebra. Each lamina fuses in the midline to form the spinous process. The lamina is partly or completely resected (laminectomy) during lumbar disc surgery to facilitate access to the disc.

Right psoas major muscle. This is a powerful hip flexor. In the clinical setting of lumbar discitis it is common to see infection tracking from the disc space into the psoas muscle to form a psoas abscess.

Right S1 nerve.

Popliteus tendon. This point represents the popliteal groove or sulcus within which the popliteus tendon inserts. The popliteus tendon is an important structure that contributes to stability of the postero-lateral corner of the knee.

Styloid process of the fibular head. Biceps femoris, a powerful hamstring muscle, attaches here along with the fibular collateral ligament and the arcuate ligament complex. The fibular styloid process can be avulsed during high energy trauma to the postero-lateral corner of the knee producing an ‘arcuate sign’ on radiographs.

Medial collateral ligament (MCL). The MCL is an important medial stabilizer of the knee, resisting valgus stress. A bony avulsion of the proximal MCL attachment may produce a non-united fragment called a Pellegrini–Stieda lesion, visible on AP radiographs.

Medial tibial spine. The medial tibial spine bears the attachment of the medial meniscal roots along with the footprint of the antero-medial bundle of the anterior cruciate ligament.

Bipartite patella. A bipartite patella is an unfused secondary ossification centre on the supero-lateral corner of the patella. These must not be mistaken for acute fractures, but may become symptomatic if the synchondrosis between the two bone fragments is disrupted following direct trauma.

Main submandibular duct. This is also known as Wharton's duct, and conveys mixed mucinous and serous secretions, which are more prone to form opaque calculi.

Intraglandular duct. On ultrasound scan examination, intraglandular ducts are visualized as small linear hypoechoic stripes.

Hyoid bone. This does not articulate with any other bone, and is held in position by the thyroid ligaments. It is highly mobile, with mobility provided by a number of muscles and ligaments. It develops from the second and third pharyngeal arches.

Condylar process of the mandible. The lateral extremity of the condyle is a small tubercle for the attachment of the temporomandibular ligament.

Coronoid process of the mandible. This is a thin triangular eminence, whose lateral surface affords insertion to the temporalis and masseter muscles.

Posterior column of the left acetabulum. The posterior and anterior columns of acetabulum provide the dominant load-bearing support of the hip joint. It is important to evaluate the integrity of the acetabular columns in the setting of pelvic trauma as fracture involvement of these structures is integral to all classification systems of acetabular fractures.

Left rectus abdominis muscle. This is a strap-like muscle encased in a fascial sheath. It inserts onto the anterior surface of the pubic symphysis and has an aponeurosis which is continuous with that of the gracilis and adductor longus muscles.

Right obturator internus. This arises from the internal surface of the medial acetabulum and inserts on the greater trochanter of the femur. Its action is to produce external rotation of the hip.

Right sartorius muscle. This arises from the anterior superior iliac spine. It has a long muscle belly directed distally and medially spanning the hip and knee joints with an insertion on the antero-medial aspect of the tibia as one of the pes anseurinus tendon group.

Greater trochanter of the left femur.

T11/T12 disc space.

T12 vertebral body.

Twelfth rib.

L1 pedicle.

L1/L2 facet joint.