Mohammad Ashraf. Abdulrahman Al-Hanbali. Ahmad Salman. 1 P a g e

Transcription

1 - 7 Mohammad Ashraf Abdulrahman Al-Hanbali Ahmad Salman 1 P a g e

2 Structures under the cover of Gluteus Maximus: 1-Bones: Ileum, Femur (Head, greater trochanter and gluteal tuberosity), Ischium (ischial tuberosity). 2- Ligaments: Sacrotuberous ligament and Sacrospinous ligament. 3- Muscles: gluteus medius, gluteus minimus, lateral rotators: (Piriformis, Obturator Internus, Superior & Inferior Gemellus, Quadratus Femoris). 4- Vessels: Superior & Inferior Gluteal Vessels (go through greater sciatic foramen), Internal pudendal vessels. 5- Nerves: Sciatic nerve, Posterior cutaneous nerve of the thigh, Nerve to Obturator internus, Nerve to Quadratous, Superior & Inferior Gluteal nerves, Pudendal nerve. 2 P a g e

3 Clinical application: *Sciatic nerve goes through greater sciatic foramen under the Piriformis muscle. This is important to know when giving intramuscular injection, and we already know how to divide the gluteal region into 4 parts. So according to the picture below we give injection in the upper lateral part to be far from the sciatic nerve, so we don t damage it, since it s so important and supplies too many muscles. Another way to determine the injection site is by putting your thumb on the posterior superior spine, hand on iliac crest and stretch your hand then inject right below your hand. *This injection is given mainly in the gluteus medius (safer because it s far from sciatic nerve), sometimes given in the g. maximus because it s bigger and has more vessels (less safe because it s closer to sciatic n.). Posterior compartment of the thigh Muscles: 1- Biceps Femoris (Short & long heads). 2-Semitendinosus. 3- Semimembranosus. 4- Hamstring (or ischial) part of Adductor Magnus. Nerve Supply: ALL supplied by Sciatic nerve. *Sciatic nerve divides into 2 nerves: Tibial nerve & Common peroneal (fibular) nerve. All 4 previous muscles are supplied by Tibial nerve, EXCEPT short head of biceps femoris which is supplied by common fibular nerve. 3 P a g e

4 *Make a connection in your mind between the position of the biceps femoris which is lateral and the position of common fibular nerve which is also lateral, and because of that part of the biceps (short head) is supplied by this nerve. Origin: All muscles originate from Ischial tuberosity, EXCEPT short head of biceps femoris (because it s short, it originates from the lateral supracondylar line on the femur). Insertion: 1- Biceps femoris: Inserts on the fibula (head/styloid process). 2- Semitendinosus: Inserts on SGS (upper part of medial surface of tibial head). 3- Semimembranosus: Inserts on the posterior part of medial condyle of the tibia. 4- Adductor magnus: Inserts on adductor tubercle on the femur. Action: All of them cross 2 joints: hip joint and knee joint. So, the action for these muscles will be flexion of the knee & extension of the hip. EXCEPT 2 muscles: Short head of biceps femoris & adductor magnus. Short head only crosses the knee joint, so it only helps with flexing the knee. Adductor magnus only crosses hip joint so the hamstring part helps with extension of the hip. In addition to that, medial muscles (Semitendinosus & semimembranosus) do medial rotation of the leg, and biceps femoris do lateral rotation. 4 P a g e

5 Ischial tuberosity Ischial tuberosity divides into 2 parts: upper & lower parts, and every part divids into another 2 parts. ^Origins of ischial tuberosity-originated muscles that mentioned in the picture are important. Lower triangular (medial) part has no muscles, but it has subcutaneous bursa (a sac contains synovial fluid) and when we sit we sit on it, so it helps in preventing direct connection between the bone and the skin when sitting. Sciatic Nerve Originates from the sacral plexus (L4, L5, S1, S2, S3). Course: From sacral plexus to greater sciatic foramen (below the piriformis), then goes to the middle of the thigh, there, gives 2 branches: common peroneal and tibial nerve. Sciatic nerve gives its branches in 5 P a g e

6 different sites from person to another. You can determine the surface anatomy of sciatic nerve by two points. The first one is the middle point between posterior superior iliac spine and the ischial tuberosity. The second one is the middle point between ischial tuberosity and greater trochanter. Posterior cutaneous nerve of the thigh Originates from sacral plexus (S1, S2, S3), then enter the gluteal region through the greater sciatic foramen below the piriformis. It supplies the posterior skin of the thigh, upper posterior part of the leg and medial lower part of the gluteal region. Popliteal fossa The back of the knee. Have 4 borders: 2 upper & 2 lower borders. 1- Upper medial: Semitendinosus, Semimembranosus. 2- Upper lateral: Biceps femoris (long head). 3- Lower medial: medial head of gastrocnemius. 4- Lower lateral: lateral head of gastrocnemius (and plantaris, but maybe absent). 6 P a g e

7 Floor: Upper part is femur, lower is tibia, and capsule of knee joint between them. Roof: skin, superficial fascia and deep fascia. Contents: 1- vessels: Popliteal artery (most deep, closest to the bone), popliteal vein (posterior to popliteal artery, continue as femoral vein), small saphenous vein (drain into popliteal vein). 2- nerves: tibial nerve (From the upper angle to the lower angle), common fibular nerve (from upper angle to lateral angle). 3- lymph nodes: from lateral side of the foot and leg. 7 P a g e

8 *Common fibular nerve turns around the neck of the fibula then divides into 2 nerves: Superficial fibular nerve & deep fibular nerve. *Common fibular nerve gives 2 branches: Lateral cutaneous nerve of the calf (supplies the upper lateral side of the leg & the anterior lateral side of the leg & the posterior lateral side of the leg) and Sural communicating branch. Tibial nerve gives a branch called Sural nerve (supplies the back of the leg and lateral side of the foot. Sural nerve goes along with small saphenous vein posterior to the lateral malleolus. Clinical case: If a patient was complaining of a mass on the popliteal fossa what can the cause possibly be? First thing you think about is the content of this fossa, and you see from what the mass is arising. If it s arising from the skin it could be sebaceous cyst or lipoma, if it s from the popliteal artery it could be aneurysm, and it could be from the lymph node, or a tumor in the femur. (What the doctor meant by this example is that we have many causes of swelling in the popliteal fossa and it could be any on of them because of the variety of the content). 8 P a g e