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(BQ) Part 2 book Clinical anatomy has contents: Surface anatomy and surface markings of the lower limb, the bones and joints of the lower limb, the arteries of the lower limb, surface anatomy of the neck, the tongue and floor of the mouth,... and other contents.
Part The Lower Limb Clinical Anatomy: Applied Anatomy for Students and Junior Doctors, Fourteenth Edition Harold Ellis and Vishy Mahadevan © 2019 John Wiley & Sons Ltd Published 2019 by John Wiley & Sons Ltd Companion website: www.ellisclinicalanatomy.co.uk/14edition Surface anatomy and surface markings of the lower limb Anatomically the upper and lower limbs are comparable to each other as regards the arrangement of the bones, joints, main muscle groups, vessels and nerves However, compared with the complex movements of the upper limb, designed to place the hand in a multiplicity of positions, together with the intricate and multiple functions of the hand, fingers and thumb, the functions of the lower limb are simple indeed – first, to act as a rigid column in the standing position and, second, to turn into a lever system when the subject walks or runs As with the upper limb, several aspects of the important clinical anatomy of the lower limb can be examined, reviewed and revised on yourself, your colleagues or your patients Bones and joints The tip of the anterior superior spine of the ilium is easily felt and may be visible in the thin subject The greater trochanter of the femur lies a hand’s breadth below the iliac crest; it is best palpated with the hip passively abducted so that the overlying hip abductors (tensor fasciae latae and gluteus medius and minimus) are relaxed In the very thin patient, the greater trochanter may be seen as a prominent bulge and its overlying skin is a common site for a pressure sore to form in such a case The ischial tuberosity is covered by gluteus maximus when one stands In the sitting position, however, the muscle slips away laterally so that weight is taken directly on the bone To palpate this bony point, therefore, feel for it uncovered by gluteus maximus in the flexed position of the hip At the knee, the patella forms a prominent landmark When quadriceps femoris is relaxed, this bone is freely mobile from side to side; note that this is so when you stand erect The condyles of the femur and tibia, the head of the fibula and the joint line of the knee are all readily palpable; less so is the adductor tubercle of the femur, best identified by running the fingers down the medial side of the thigh until they are halted by it, the first bony prominence so to be encountered The tibia can be felt along the entire length of its anterior subcutaneous border from the tibial tuberosity above, which marks the insertion of the quadriceps tendon, to the medial malleolus at the ankle The subcutaneous surface of the tibia, which can be felt immediately medial to its subcutaneous border, is crossed by two structures – the long saphenous vein, which is readily visible immediately in front of the medial malleolus of the tibia, and the adjacent saphenous nerve The head of the fibula, as noted previously, is easily palpable; note that it lies below and towards the posterior part of the lateral tibial condyle Distal to its neck, the fibula ‘disappears’ as it dives into the muscle mass of the peroneal muscles, becoming subcutaneous distally The fibula is subcutaneous for its terminal 7 cm (3 in) above the lateral malleolus The latter extends more distally than the stumpier medial malleolus of the tibia 217 218 The lower limb Immediately in front of the malleoli can be felt a block of bone which is the head of the talus Feel it move up and down in dorsiflexion and plantarflexion of the ankle The tuberosity of the navicular stands out as a bony prominence 2.5 cm (1 in) in front of the medial malleolus; it is the principal point of insertion of tibialis posterior The base of the 5th metatarsal is easily felt on the lateral side of the foot and is the site of insertion of peroneus brevis If the calcaneus (os calcis) is carefully palpated, the peroneal tubercle can be felt 2.5 cm (1 in) below the tip of the lateral malleolus and the sustentaculum tali 2.5 cm (1 in) below the medial malleolus; these represent pulleys, respectively, for peroneus longus and for flexor hallucis longus Bursae of the lower limb A number of the bony prominences described in the previous section are associated with overlying bursae, which may become distended and inflamed: the one over the ischial tuberosity may enlarge with too much sitting (‘weaver’s bottom’); that in front of the patella is affected by prolonged kneeling forwards, as in scrubbing floors or hewing coal (‘housemaid’s knee’, the ‘beat knee’ of north‐country miners, or prepatellar bursitis); whereas the bursa over the ligamentum patellae is involved by years of kneeling in a more erect position – as in praying (‘clergyman’s knee’ or infrapatellar bursitis) Young women who wear fashionable but tight shoes are prone to bursitis over the insertion of the Achilles tendon (calcaneal tendon or tendo calcaneus) into the calcaneus and may also develop bursae over the navicular tuberosity and dorsal aspects of the phalanges A ‘bunion’ is a thickened bursa on the inner aspect of the first metatarsal head, usually associated with hallux valgus deformity Note that the bursae that may develop (and become inflamed) over the calcaneus, navicular, the phalanges and the head of the first metatarsal are called adventitial bursae They are not found in normal anatomy but occur only under the pathological conditions described This is in contrast to the pre‐ and infrapatellar bursae, which are normal anatomical structures and which may become distended with fluid as a result of repeated trauma Mensuration in the lower limb Measurement is an important part of the clinical examination of the lower limb Unfortunately, students find difficulty in carrying this out accurately and still greater difficulty in explaining and interpreting the results they obtain, yet this is nothing more or less than a simple exercise in applied anatomy First note the differences between real and apparent shortening of the lower limbs Real shortening is due to actual loss of bone length; for example, when a femoral fracture has united with a good deal of overriding of the two fragments Apparent shortening is due to a fixed deformity of the limb (Fig. 147) Stand up and flex your knee and hip on one side, imagine Surface anatomy and surface markings of the lower limb 219 Fig. 147 Apparent shortening – one limb may be apparently shorter than the other because of fixed deformity; the legs in this illustration are actually equal in length but the right is apparently considerably shorter because of a gross flexion contracture at the hip Apparent shortening is measured by comparing the distance from the umbilicus to the medial malleolus on each side Umbilicus to medial malleolus these are both ankylosed at 90° and note that, although there is no loss of tissue in this limb, it is apparently some 60 cm (2 ft) shorter than its partner If there is a fixed pelvic tilt or fixed joint deformity in one limb, there may be this apparent difference between the lengths of the two limbs By experimenting on yourself you will find that adduction apparently shortens the limb, whereas it is apparently lengthened in abduction To measure the real length of the limbs (Fig. 148), overcome any disparity due to fixed deformity by putting both limbs into exactly the same position; where there is no joint fixation, this means that the patient lies with his pelvis ‘square’, his limbs abducted symmetrically and both limbs lying flat on the couch If, however, one hip is in 60° of fixed flexion, for example, the other hip must first be put into this identical position The length of each limb is then measured from the anterior superior iliac spine to the medial malleolus In order to obtain identical points on each side, slide the finger upwards along Poupart’s inguinal ligament and mark the bony point first encountered by the finger Similarly, slide the finger upwards from just distal to the malleolus to determine the apex of this landmark on each side To determine apparent shortening, the patient lies with his legs parallel (as they would be when he stands erect) and the distance from umbilicus to each medial malleolus is measured (Fig. 147) Now suppose we find 10 cm (4 in) of apparent shortening and 5 cm (2 in) of real shortening of the limb; we interpret this as meaning that 5 cm (2 in) of the shortening is due to true loss of limb length and another 5 cm (2 in) is due to fixed postural deformity 220 The lower limb Anterior superior iliac spine to medial malleolus If the apparent shortening is less than the real, this can only mean that the hip has ankylosed in the abducted, and hence apparently elongated, position Note this important point: one reason why the orthopaedic surgeon immobilizes a tuberculous hip in the abducted position is that, when the hip becomes ankylosed, shortening due to actual destruction at the hip (i.e true shortening) will be compensated, to a considerable extent, by the apparent lengthening produced by the fixed abduction Having established that there is real shortening present, the examiner must then determine whether this is at the hip, the femur or the tibia, or at a combination of these sites At the hip Place the thumb on the anterior superior spine and the index finger on the greater trochanter on each side; a glance is sufficient to tell if there is any difference between the two sides Measuring Nelaton’s line and Bryant’s triangle is seldom undertaken in clinical practice these days Nevertheless, some examiners remain inclined to asking questions about them (Fig. 149) Nelaton’s line joins the anterior superior iliac spine to the ischial tuberosity and should normally lie above the greater trochanter; if the line passes through or below the trochanter, there is shortening at the head or neck of the femur Bryant’s triangle might be better termed ‘Bryant’s T’ because it is not necessary to construct all of its three sides With the patient supine, a perpendicular is dropped from each anterior superior spine and the Fig. 148 Measuring real shortening – the patient lies with the pelvis ‘square’ and the legs placed symmetrically Measurement is made from the anterior superior spine to the medial malleolus on each side Surface anatomy and surface markings of the lower limb 221 Anterior superior iliac spine Fig. 149 (a) Nelaton’s line joins the anterior superior iliac spine to the ischial tuberosity – normally this passes above the greater trochanter (b) Bryant’s triangle – in the supine subject, drop a vertical from each superior spine; compare the perpendicular distance from this line to the greater trochanter on either side (There is no need to complete the third side of the triangle.) Anterior superior iliac spine Ischial tuberosity (a) Nelaton’s line Greater trochanter (b) Bryant’s triangle istance between this line and the greater trochanter compared on each d side (The third side of the triangle, joining the trochanter to the anterior spine, need never be completed.) At the femur Measure the distance from the anterior superior spine (if hip disease has been excluded) or from the greater trochanter to the line of the knee joint (not to the patella, whose position can be varied by contraction of the quadriceps) At the tibia Compare the distance from the line of the knee joint to the medial malleolus on each side Muscles and tendons Quadriceps femoris forms the prominent muscle mass on the anterior aspect of the thigh; its insertion into the medial aspect of the patella can be seen to extend more distally than on the lateral side In the well‐developed subject, sartorius can be defined when the hip is flexed and externally rotated against resistance It extends from the anterior superior iliac spine to the medial side of the upper end of the tibia It forms the lateral border of the femoral triangle, and is an important landmark Gluteus maximus forms the bulk of the buttock and can be felt to contract in extension of the hip Gluteus medius and minimus and the adductors can be felt to tighten, respectively, in resisted abduction and adduction of the hip 222 The lower limb Define the tendons around the knee joint with the joint comfortably flexed to about 90°: • laterally – the biceps tendon passes to the head of the fibula, the i liotibial tract lies approximately 1.25 cm (0.5 in) in front of this tendon and passes to a tubercle on the anterior aspect of the lateral condyle of the tibia; • medially – the bulge which one feels is the semimembranosus insertion on which two tendons, gracilis, medially and more anteriorly, and semitendinosus, laterally and more posteriorly, are readily palpable posteriorly – between the tendons of biceps and semitendinosus can be felt the heads of origin of gastrocnemius This muscle, with soleus, forms the bulk of the posterior bulge of the calf; the two end distally in the Achilles tendon (calcaneal tendon) At the front of the ankle (Fig. 150) the tendon of tibialis anterior lies most medially, passing to its insertion at the base of the first metatarsal and the medial cuneiform More laterally, the tendons of extensor hallucis longus and extensor digitorum longus are readily visible in the dorsiflexed foot Peroneus longus and brevis tendons pass behind the lateral malleolus The tendon of peroneus tertius can be felt on careful palpation on the lateral aspect of the dorsum of the foot as this tendon passes to the base of the 5th metatarsal This is of more than academic interest (Fig. 150) Peroneus tertius is present only in the human Only humans stand on the whole sole of the foot; lower mammals stand and walk on tiptoe Presumably peroneus tertius has evolved in humans as a detachment from the lateral aspect of extensor digitorum longus to assist in the development of the plantigrade human foot Behind the medial malleolus, working from the medial to the lateral side, lie the tendons of tibialis posterior and flexor digitorum longus, the posterior tibial artery with its venae comitantes, the tibial nerve and, finally, flexor hallucis longus (Fig. 151) Vessels The femoral artery (Fig. 152) can be felt pulsating at the mid‐inguinal point, halfway between the anterior superior iliac spine and the pubic symphysis The upper two‐thirds of a line joining this point to the adductor tubercle, with the hip somewhat flexed, abducted and externally rotated, accurately indicates the surface marking of this vessel A finger on the femoral pulse lies directly over the head of the femur, immediately lateral to the femoral vein (and the termination of the great saphenous vein) and a finger’s breadth medial to the femoral nerve The pulse of the popliteal artery is often not easy to detect It is most readily felt with the subject prone, the subject’s knee flexed and muscles relaxed The pulse is sought by firm pressure downwards and forwards against the popliteal surface of the femur The pulse of dorsalis pedis (Fig. 150) is felt between the tendons of extensor hallucis longus and extensor digitorum longus on the dorsum of the foot – it is absent in approximately 2% of normal subjects The posterior tibial artery (Fig. 151) may be felt a finger’s breadth below and behind the Surface anatomy and surface markings of the lower limb 223 Peroneus brevis Anterior tibial artery Perforating branch of peroneal artery Superior and inferior extensor retinacula Dorsalis pedis artery Extensor digitorum longus and brevis Peroneus tertius Tibialis anterior Extensor hallucis longus Extensor digitorum brevis slip to hallux Fig. 150 The structures passing over the dorsum of the ankle (right ankle, anterior aspect) medial malleolus In approximately 1% of healthy subjects this artery is replaced by the peroneal (fibular) artery The absence of one or both pulses at the ankle is not, therefore, in itself diagnostic of vascular disease The small (or short) saphenous vein commences as a continuation of the lateral limb of the subcutaneous venous network on the dorsum of the foot, runs proximally behind the lateral malleolus, and terminates by draining into the popliteal vein behind the knee The great (or long) saphenous vein arises as a continuation of the medial limb of the dorsal network of veins and passes proximally in front of the medial malleolus, with the saphenous nerve anterior to it, to enter the femoral vein in the groin, 2.5 cm (1 in) below the inguinal ligament and immediately medial to the femoral pulse 224 The lower limb Posterior tibial Vein Nerve Artery Flexor digitorum longus Medial malleolus Achilles tendon Flexor hallucis longus Flexor retinaculum Tibialis posterior Fig. 151 The structures passing behind the medial malleolus (right ankle, medial aspect) Anterior superior iliac spine Inguinal ligament Midline Femoral artery Adductor hiatus in adductor magnus Popliteal artery Adductor tubercle Fig. 152 The surface markings of the femoral artery; the upper two‐thirds of a line joining the mid‐inguinal point (halfway between the anterior superior iliac spine and the symphysis pubis) to the adductor tubercle .. .Clinical Anatomy: Applied Anatomy for Students and Junior Doctors, Fourteenth Edition Harold Ellis and Vishy Mahadevan © 20 19 John Wiley & Sons Ltd Published 20 19 by John Wiley... approximately 2% of normal subjects The posterior tibial artery (Fig. 151) may be felt a finger’s breadth below and behind the Surface anatomy and surface markings of the lower limb 22 3 Peroneus... shortening and 5 cm (2 in) of real shortening of the limb; we interpret this as meaning that 5 cm (2 in) of the shortening is due to true loss of limb length and another 5 cm (2 in) is due to fixed