Morphology of saphenous nerve in cadavers: a guide to saphenous block and surgical interventions

Abstract

The knowledge about detailed morphology and relation of saphenous nerve is important to obtain successful saphenous nerve regional blocks to achieve pre- and post-operative anesthesia and analgesia, nerve entrapment treatments and to avoid damage of saphenous nerve during knee and ankle surgeries. The literature describing detailed morphology of saphenous nerve is very limited. We dissected 42 formalin fixed well embalmed cadaveric lower limbs to explore detailed anatomy, relation and mode of termination of saphenous nerve and measured the distances from the nearby palpable bony landmarks. The average distance of origin of saphenous nerve from inguinal crease was 7.89±1.42 cm, the distance from upper end of medial border of patella to saphenous nerve at that level was 8.11±0.85 cm, distance from tibial tuberosity was 7.53±0.98 cm and from midpoint of anterior border of medial malleolus was 0.45±0.14 cm. Saphenous nerve provided two infrapatellar branches at the level of mid to lower limit of patellar ligament in 90% cases. It was in close contact or adhered to great saphenous vein across the lower 2/3rd of leg lying either anterior, posterior or deep to the vein. The saphenous nerve terminated by bifurcating proximal to medial malleolus in majority of cases though no obvious bifurcation was observed in 9.52% cases. The detailed morphology, relations and the distances from palpable bony landmarks may be helpful for clinicians to achieve successful saphenous nerve block and to avoid saphenous nerve damage and related complications during orthopedic procedures.

Nerve Injury in venous procedures: Malpractice, characteristics, and strategies to avoid it

“…The terminal and the longest sensory branch of the femoral nerve is the saphenous nerve 13 (Fig 3). In the thigh, within the femoral triangle and adductor canal, the SN lay in a deeper plane in comparison to GSV and remained separated from the vein by a considerable amount of fat, fascia, and sartorius muscle 14 . In the thigh, it courses subfascial and follows the superficial femoral artery 13 .…”

“…In the thigh, it courses subfascial and follows the superficial femoral artery 13 . Beyond the adductor canal, the SN passed between sartorius and gracilis muscles and became subcutaneous 14 . At the medial aspect of the knee and along with the upper third of the leg, SN and GSV remained separated by connective tissue sleeves of varying thickness ranging 0.5-2.5 cm depending on the thickness of the adipose layer.…”

“…The point from where SN and GSV had an intimately related course ranged between 26 and 35 cm from the tip of the medial malleolus. A study recommends avoiding lower 2/3rd of the leg while harvesting saphenous venous graft to avoid damage to SN and subsequent neuropathy 14 .…”

Arriving at SKINTED (Surgery of the Knee, Injury to the Infrapatellar Branch of the Saphenous Nerve, Traumatic Eczematous Dermatitis): A Case Report

“…The longest branch of the femoral nerve, the saphenous nerve (SN), supplies sensation to the medial aspect of the knee, leg, and foot. It originates from the femoral nerve within the femoral triangle in the thigh and descends the adductor canal, where it emerges as an infrapatellar branch that goes subcutaneously from the medial to the lateral side below the patella [ 3 ]. It is prone to trauma after surgical procedures around the knee, primarily TKR [ 4 ].…”

Recurrent position and innervation pattern of recurrent peroneal nerve: A cadaveric study

“…Damage to the infrapatellar branch of the saphenous nerve by several knee surgeries results in anteroinferior and medial knee pain [1]. Rousseau et al [2] reported that damage to the recurrent peroneal nerve (RPN) due to increasing internal pressure of the lateral compartment resulted in pain or tenderness to the lateral border of the proximal patellar tendon.…”