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Saphenous Nerve Entrapment

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Other Names

  • Saphenous Neuropathy
  • Surfer's neuropathy
  • Entrapment Neuropathy of the Infrapatellar Branch of the Saphenous Nerve
  • Infrapatellar Saphenous Neuralgia
  • Saphenous neuroma
  • Saphenous neuropathic pain syndrome
  • Gonalgia Paresthetica




  • Incidence is not well documented in the literature


Saphenous nerve anatomy at the medial knee. Note the relationship of sartorius to the infrapatellar branch (IPS nerve) and the saphenous nerve[1]
  • Misdiagnosis
    • Easily missed and overlooked by physicians
    • Often misdiagnosed as more common causes of medial knee pain (meniscus, MCL, PFPS, knee OA, pes anserine pain)
    • Often fail other common treatment modalities due to misdaignosis


  • Entrapment at the medial knee[2]
    • Courses deep to Sartorius traveling laterally to medially as it descends the thigh
    • Nerve exits through adductor (Hunter's) canal at medial knee, then travels distally into the calf
  • Iatrogenic during orthopedic surgery
  • Other causes
    • Prolonged periods of kneeling
  • Case reports following
    • Blunt trauma to medial thigh[8]


  • Saphenous Nerve
    • Sensory branch of the Femoral Nerve
    • Distribution is medial leg
    • Medial femoral condyle: divides into infrapatellar branch, terminal saphenous branch
  • Infrapatellar branch: innervates the skin below the patella, anterior inferior knee capsule
  • Terminal saphenous branch: innervates the skin of the anterior and medial lower leg

Risk Factors

  • Sports
    • Surfing

Differential Diagnosis

Clinical Features

  • History
    • The patient will complain of vague medial knee pain
    • Can radiate down medial aspect of leg into the foot
    • Pain may or may not be worse with movement
    • Pain may be described as dull, achy, burning
    • Worse with stairs, sitting, prolonged walking[9]
  • Physical Exam: Physical Exam Knee
    • Medial tibial fossa may demonstrate swelling
    • May be tender over medial tibial plateau or fossa, medial patellar facet, retinaculum
    • Diminished sensation to light touch of anteromedial knee
    • Hypesthesia or allodynia may be present
    • Knee flexion and abduction may increase pain and give false positive to meniscus etiology
  • Special Tests
    • Tinels Test: percussion over the adductor canal or medial tibial fossa may replicate pain
      • Adductor canal: approximately 7 cm proximal, 10 cm medial to superior pole of patella
      • Infrapatellar branch: 3-5 cm medial to the medial mid-patella border with knee in extension


Demonstration of diagnostic injection for infrapatellar branch[1]



  • Described in literature
  • Questionable utility
    • Likely less valuable than a diagnostic injection

Diagnostic Nerve Block

  • Description for infrapatellar branch
    • Knee is in flexion
    • Isolate the point of maximal tenderness in the medial tibial fossa
    • Needle enters from below, directed towards tibial tubercle and advanced to bone
    • Consider adding corticosteroid to injection
    • Use small volumes (1-2 mL) to avoid local anesthetic infiltrating other areas and avoiding confounding
  • Consider using ultrasound guidance


  • Not applicable





  • Indications
    • Failure of conservative measures
  • Technique
    • Surgical decompression[12]
    • Neurolysis
    • Neurectomy

Rehab and Return to Play


  • Needs to be updated

Return to Play/ Work

  • Needs to be updated

Complications and Prognosis


  • Unknown


  • Chronic knee pain

See Also


  1. 1.0 1.1 Trescot, Andrea M., Michael N. Brown, and Helen W. Karl. "Infrapatellar saphenous neuralgia-diagnosis and treatment." Pain physician 16.3 (2013): E315-24.
  2. Kalenak, Alexander. "Saphenous nerve entrapment." Operative Techniques in Sports Medicine 4.1 (1996): 40-45.
  3. Dellon AL, Mont MA, Krackow KA, Hungerford DS. Partial denervation for persistent neuroma pain after total knee arthroplasty. Clin Orthop Relat Res 1995; 316:145-150.
  4. Papastergiou SG, Voulgaropoulos H, Mikalef P, Ziogas E, Pappis G, Giannakopoulos I. Injuries to the infrapatellar branch(es) of the saphenous nerve in anterior cruciate ligament reconstruction with four-strand hamstring tendon autograft: Vertical versus horizontal incision for harvest. Knee Surg Sports Traumatol Arthrosc 2006; 14:789-793.
  5. Kartus J, Movin T, Karlsson J. Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts. Arthroscopy 2001; 17:971-980
  6. Mochida H, Kikuchi S. Injury to infrapatellar branch of saphenous nerve in arthroscopic knee surgery. Clin Orthop Relat Res Nov 1995; 320:88-94.
  7. Leliveld MS, Verhofstad MHJ. Injury to the infrapatellar branch of the saphenous nerve, a possible cause for anterior knee pain after tibial nailing? Injury 2012; 43:779-783.
  8. Herman, Daniel C., and Kevin R. Vincent. "Saphenous neuropathy—a masquerading cause of anteromedial knee pain." Current sports medicine reports 17.6 (2018): 177.
  9. Morganti CM, McFarland EG, Cosgarea AJ. Saphenous neuritis: a poorly understood cause of medial knee pain. J. Am. Acad. Orthop. Surg. 2002; 10:130–7.
  10. Akbas M, Luleci N, Dere K, Luleci E, Ozdemir U, Toman H. Efficacy of pulsed radiofrequency treatment on the saphenous nerve in patients with chronic knee pain. J Back Musculoskelet Rehabil 2011; 24:77-82.
  11. Trescot A. Cryoanalgesia in interventional pain management. Pain Physician 2003; 6:345-360.
  12. Lippitt, A. B. "Neuropathy of the saphenous nerve as a cause of knee pain." Bulletin (Hospital for Joint Diseases (New York, NY)) 52.2 (1993): 31-33.
Created by:
John Kiel on 15 August 2021 22:10:24
Last edited:
4 October 2022 15:56:10