Indications
- Septic arthritis needing open drainage and washout
- Synovial biopsy, synovectomy and loose body removal
- Anterior approach suits anterior joint and femoral head access
- Posterior approach gives dependent drainage and posterior column access
Position
- Smith-Petersen uses supine with a sandbag under the ipsilateral buttock
- Watson-Jones works supine or lateral
- Hardinge direct lateral works supine or lateral
- Moore and Kocher-Langenbeck use lateral decubitus with the knee flexed to relax the sciatic nerve
Landmarks and Incision
- Smith-Petersen runs along the anterior iliac crest to the ASIS, then distally toward the lateral patella
- Watson-Jones starts distal to the ASIS, runs to the greater trochanter and continues down the femur
- Hardinge is a midlateral incision centred on the greater trochanter
- Moore is a curved incision behind the greater trochanter that continues down the femoral shaft
Internervous Plane
- Smith-Petersen uses sartorius (femoral nerve) and tensor fasciae latae (superior gluteal nerve)
- Watson-Jones lies between tensor fasciae latae and gluteus medius, both superior gluteal nerve, so is not truly internervous
- Hardinge and Moore have no true internervous plane
Deep Dissection
- Smith-Petersen ligates the ascending branch of the lateral circumflex femoral artery crossing the plane
- Smith-Petersen detaches rectus femoris to expose the anterior capsule
- Hardinge splits gluteus medius no more than about 5 cm above the trochanter to spare the superior gluteal nerve
- Moore divides piriformis and the conjoint tendon close to the femur and leaves quadratus femoris intact
Structures at Risk
- Lateral femoral cutaneous nerve at the ASIS and over sartorius
- Femoral neurovascular bundle medial to sartorius under retractors
- Superior gluteal nerve in Watson-Jones and Hardinge
- Sciatic nerve with posterior retraction, relieved by hip extension and knee flexion
- Deep branch of the medial circumflex femoral artery at quadratus femoris and obturator externus
Extension
- Smith-Petersen extends along the iliac crest to expose the iliac wing
- Kocher-Langenbeck extends distally along the femur
- Trochanteric flip osteotomy with surgical dislocation widens access while obturator externus protects the medial circumflex femoral artery
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 12 October 2026.