Variations involving the relationship between the sciatic nerve and the piriformis muscle are commonly classified based on Beaton and Anson’s classification. Mnemonic: I Prefer Smart Anatomy For Perfect nerve-sparing Type Mnemonic Meaning Description Prevalence I I Inferior Undivided sciatic nerve passes below piriformis 87% II Prefer Piercing Peroneal pierces, tibial…
Tag: Orthopedics
Section Editor: Dr. Sulabh Kumar Shrestha, MBBS, PGY1 Orthopedics
Surgical Skills 
Direct Lateral Approach to Radial Shaft
Position: Elbow flexed 90 degree and forearm in mid-prone Landmarks: Skin incision: Centered over fracture in a straight imaginary line joining lateral epicondyle of humerus and tip of radial styloid Superficial dissection: Subcutaneous tissue and deep fascia are incised along the line of skin incision Deep dissection: Interval is developed…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Iliac Cortical Density (ICD)
Synonym: Iliac Cortical Line Iliac cortical densities (ICD) are the overlap of the true pelvis posterior to the acetabulum which is used as a proxy for the slope of the sacral ala. Importance: The entry point should be anterior in S1 and inferior to the iliac cortical density (ICD), which…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Crowe Classification in Adult Hip Dysplasia
Crowe Classification Class I: <50% subluxation or proximal displacement <10% of pelvic height Class II: 50-75% subluxation or proximal displacement 10-15% of pelvic height Class III: 75-100% subluxation or proximal displacement 15-20% of pelvic height Class IV: >100% subluxation or proximal displacement >10% of pelvic height and deficient true acetabulum…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Coccyx Types
Postacchini and Massobrio Classification (Nathan Modification) Can be classified into 6 types: Type I (slight curve): Curved slightly forward with apex pointing caudally (>50% incidence) Type II (forward curve): More prominent ventral curvature with coccyx apex pointing anteriorly (8-32% incidence) Type III (sharp angle): Acute anterior angulation of coccyx but…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Morel Lavallee Lesion
Definition: Post-traumatic closed degloving injury, in which the skin and subcutaneous tissue is detached from the underlying fascia by a shearing force which can disrupt perforating vessels and nerves, creating a potential space that fills with blood, lymph, debris and fat (necrotic and/or viable). Clinical features: The diagnosis can be…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Corona Mortis
Synonym: Crown of Death Definition: Retropubic vascular anastomoses between the obturator and external iliac systems Location: Behind the superior pubic ramus at varying distance from the symphysis pubis (range 40-96 mm) Morphologies: a. Arterial corona mortis (8-65% incidence): b. Venous corona mortis (40-96% incidence): c. Combined arterial and venous corona…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Frozen Shoulder : Mnemonics
Synonym: Adhesive capsulitis of shoulder Features: Mnemonic: ICE CAPS Sequence for Manipulation under anesthesia (MUA): Mnemonic: FEAR