MRCS NOTES (1) Brachial plexus: (1) Roots --> b/w Scalenous Anterior and Medius (2) Trunks --> Posterior triangle of neck (3) Divisions --> behind clavicle (4) Cords --> In Axilla ( related to 2nd part of axillary artery) (2) Phrenic nerve descends on anterior aspect of scalenous anterior and is in the posterior triangle of neck throughout its course in the neck. (3) Deep branch of ulnar nerve supplies interossei and adductor pollicis (froments sign when this is damaged) (1) Superficial branch supplies plamaris brevis. (2) Middle finger has no palmar interossei. (4) Recurrent branch of median nerve is purely motor and supplies the thenar eminence. (5) Ulnar nerve is medial to ulnar artery and they both pass through the canal of Guyon canal at the wrist. (6) Ganzer muscle is an abberation of flexor pollicis longus and may affect the anterior interoseeus nerve. (7) Extensor Indicis is medial to extensor to extensor digitorum (8) Right coronary artery originates from the anterior sinus, left coronary artery originates from the left posterior sinus. (9) Coronary sinus tributaries are great cardiac vein(running in anterior interventricular groove), middle cardiac vein(running in posterior IV groove), and small cardiac vein(along the marginal artery). (1) Venea corda minimie/smallest cardiac veins/thebasian veins drain directly into the heart. (2) A left SVC drains into the coronary sinus. (10)Right coronary artery supplies SA node in 60% of cases and AV node in 80% of cases. RCA arises from anterior aortic sinus and LCA from left posterior aortic sinus. (11)Heart valves are made up of extracellular matrix rich is dense collagen, elastin and prostaglandins, along with valve interstitial cells. (12)Porcine heart valves have the benefit of avoiding anticoagulation but have to be replaced after 10 years because they get stenosed due to calcifications. (13)Oblique cardiac recess is between pulmonary veins( LA and pericardium) (1) Transverse is between pulmonary trunk and aorta anteriorly, and SVC and left atrium posteriorly. (14)Great cerebral vein is formed by the union of 2 internal cerebral veins, and joins the inferior saggital sinus to form the straight sinus. (15)Pia mater forms the choroid plexus with astrocytes. 1 of 19 (16) Dorsal rami of C1, L4 and L5 have no cutaneous branches. (17) Diplopia walking downward and unable to abduct is trochlear nerve injury. (18)Danger area of face is drained by (1) anterior facial and ophthalmic veins (2) Pterygoid venous plexus (19)Opening of ampulla of Vater in on posteromedial aspect of 2nd part of duodenum(major duodenal paiila), use monopolar cutting for sphincterotomy. (1) Use monopolar blend for polypectomy (20)Ischial spine: (1) Anatomical landmark for puedendal nerve block, used for episiotomy. (2) At the level of vesico-ureteric junction(for Xray detection of stones) (3) marks the pelvic outlet. (4) Level of levator ani (21)Anal canal lympahtics drain to superficial inguinal nodes below the denate line and internal illiac nodes above the dentate line. (22) Distal articulation of cuboid and hamate are 4th and 5th metatarsal/metacarpal. Capitate is the largest carpal bone and articulates with 2nd,3rd and 4th metacarpals. (1) Scaphoid and lunate artiulate with radius. (2) Capitate is related to profundus tendon (23)Axillary nerve supplies deltoid and teres MINOR. (1) teres major is supplied by lower subscapular nerve and thoracodorsal nerve aka middle subscapular nerve. (24)Nerve injury at hip surgery (1) Posterior approach ---> Sciatic nerve (2) Postolateral approach ---> Superior gluteal nerve (25)Meralgia parasthetica is burning pain on anterolateral part of proximal thigh due to damage of lateral cutaneous nerve of thigh under the lateral aspect of inguinal ligament. (1) LCN of thigh and psoas major are both L2, L3. (2) Femoral nerve supplies illiacus and lies on it. (26) In carotid endarterectomy: (1) Hypoglossal nerve can be damaged (2) Facial vein is divided (27)Cervical vertebrae: (1) bifid spinous process, small body (2) C7 is known as vertebrae prominens because it has a long spine (3) foramen transversum is present in upper 6 vertebrae for transmission of vertebral artery 2 of 19 (28)Thyroid horomones decrease oxidative phosphorylation by increasing uncoupling proteins so that increase heat production takes place, so thyroid horomones increase in responce to cold and decrease in responce to heat. (1) If used alone for preop, iodine can intensify thyrotoxicosis. (2) PTU increases vascularity of thyroid gland. (29)Pregnancy and other growth states are risk factor for folic acid deficiency. (30)Hassal corpuscles are found in the thymus, which is derived from 3rd parangeal pouch, along with inferior thyroid. (31)Most common cause of ARDS is sepsis. (32)Hepatomegaly in Kwashiorkor patients is due to fatty infiltrates. (33)Morton neuroma: (1) aka intermetatarsal neuroma, betweeen metatarsals causes constant pain in foot. the interdigital nerve transverses inferior to the intermetatarsal ligament. It may be compressed or stretched by repetitive toe flexion and extension. This causes reactive overgrowth of connective tissue and arterial sclerosis. This leads to nerve ischemia and atrophy. Pain is due to nerves getting caught up in the scar tissue. (2) Feels like walking on a marble (3) Treatment involves getting a soft sole, NSAIDS, Sclerosing/Steroid Injections. (4) Stress/March fracture is fracture of 2nd metatarsal(longest and thinest) head due to repeated trauma. (5) Freiberg disease is anterior metatarsalagia of 2nd metatarsal in pubertal growth. (34)Pilon fracture is a fracture of tibia and fibula at the lower aspect, its fixation is done by a external fixator known as delta frame. (1) Delta frame has a transcalcaneal pin and a tibial pin (2) Once soft tissue injury is resolved 2-3 weeks and ORIF is done with plates and screws. (35)Histology of RA: (1) Hallmark is perivascular mononuclear infiltrates in the synvoium (2) A pannus contains inflammatory cells, granulomatous tisse and fibroblasts. (3) A rheumatoid nodule contain necrobiotic granulomatous inflammation. (36)Claudication: (1) Thigh claudication : Illiac vessels, if buttocks are involved then common illiac(leiriche syndrome) (2) Calf claudication : due to atheroma in superficial femoral artery at the level of the adductor hiatus. (3) Ankle claudication : Popliteal artery (37)Doppler: (1) Frequency observed after reflection of ultrasound waves varies on the approach of the fluid. Higher frequency of approaching fluid and lesser frequency of leaving fluid. (2) A normal artery has a triphasic waveform (3) Mild stenosis : Increase in velocity and a biphasic waveform (4) Tight stenosis : Even more increase in velocity and a monophasic waveform (5) Distal to stenosis : decreased velocity and a monophasic signal. (38)Enhanced Recovery Protocol aka ERAS: 3 of 19 (1) Perioperative counselling (2) Optimization of nutrition ( Carbohydrate loading 2h before surgery) (3) Standarised analgesia and anasthetic regimens (4) Early mobilisation (39) Recommendations: (1) No bowel preparation for GI surgery except surgery of rectum (2) Fleet anema may also be used for left sided anastomosis (3) Avoid elective drains except APR surgery (4) Smoking cessation for 4 weeks and decrease comorbids including obesity (5) Avoid anxiolytics in hip replacement surgery (6) Give antiemetics atleast 2, if risk factors are present (7) Avoid prophylactic NG tubes (40)Pain of stone in renal pelvis is reffered to T11, T12, L1 (41)Symptoms of testicular torsion plus black spot above testes is likly to be torsion of hyatid of morgagni. It is called the blue dot sign and is seen because the torsion is of hemorrhagic type. (42)Fat embolism syndrome has neurological symptoms and a rash, onset is usually 12h after insult. (43)Use isoproterenol or epinephrine for bradycardia in most transplant patients but give low dose as there is increase sensitivity to these sympathetomimetics. (1) Use bipolar diathermy if pacemaker is present (44)Tail of pancreas is present in lienorenal ligament and may be damaged while ligation of splenic hilum takes place in spleenectomy. This will result in hyperamylasemia. (1) ligation of short gastric vessels in gastrosplenic ligamant may cause direct damage to funus of stomach and a gastrocutaneous fistula. (45) Thrombocytosis usually occours immediately following spleenectomy as the splenic reserve is mobilised, if more than 1M, aspirin is considered. (1) Other immediate changes include reticuloctosis. (2) Late changes include increase in monocytes and lymphocytes. (3) Blood picture includes Howell jolly bodies, heinz bodies, pappenheimer bodies, poikilocytosis, target cells. (4) Most sensitive scan for hypospleenism is radionucleotide labelled red cell scan (46)Descent of testes is anatomically aided by gubernaculum while the horomoes testosterone and CGRP aid in the inguinoscrotal phase. (1) Cryptochidism is used for undescended testes after 3 months of age, a laproscopy is advised to locate testes not found on palpation. (2) Surgical correction is recommended after 6 months. (47) Parametric data is tested by: Student T test(paired and unpaired) if two variables are being compared. If more than 2 are being compared then ANOVA test is used. (1) Non parametric data is tested by kruskal wallis test if more than 2 variables, otherwise Wilcoxon test for paired data and Mann Whitney test for unpaired data. (2) Post research multiple correctional analysis is done by bonferroni method. (3) Pretest probabilities(PPV and NPV) are dependent on prevalence. (4) Corelation coefficient in parametric data is Pearson, in non parametric spearman. (5) Case control studies are done for rare conditions. 4 of 19 (48) A menisceal cyst usually presents as a slowly growing painful lateral swelling in knee. It can be treated by partial arthoscopic menisectomy. (49)Femur fracture: (1) If externally rotated : Neck, trochanteric fracture( neck fracture causes pain in groin, trochanteric causes pain in trochancteric area) (2) Adducted hip : Dashboard injury, posterior dislocation of femur, associated with sciatic nerve injury. Should be immediately reduced by closed reduction(within 6 hours) to avoid osteonecrosis. If unsuccessful, or unstable ORIF.