Neuroma of the Infrapatellar branch of the saphenous nerve following Total knee Arthroplasty: a case report

Abstract

Background: Injury to the infrapatellar branch of the saphenous nerve (IBSN) is common during total knee arthroplasty (TKA) with a standard midline skin incision. Occasionally, painful neuromas form at the transection of nerve and cause pain and limitation of the range of motion of the knee joint. Case presentation: A 70-year-old woman experienced right knee pain and stiffness for 4 years after TKA. Physical assessment revealed medial tenderness; Tinel's sign was positive. Radiographs revealed that the prosthesis was wellplaced and well-fixed. She was diagnosed with arthrofibrosis and possible neuroma after TKA. She underwent right knee exploration, neurectomy, adhesiolysis and spacer exchange. The neuroma-like tissue was sent for pathological examination. The patient recovered uneventfully and at 3-month follow-up reported no recurrence of pain or stiffness. The pathological report confirmed the diagnosis of neuroma. Conclusions: IBSN injury should be a concern if surgeons encounter a patient who has pain and stiffness after TKA. Tinel's sign, local anesthetic injection, MRI and ultrasound could help the diagnosis and identify the precise location of neuroma. Surgical intervention should be performed if necessary.

Treatment options for entrapment neuropathy of infrapatellar branch of saphenous nerve post knee arthroplasty: a case report

“…There has been discussion on performing ultrasound and MRI in the literature, but it was not considered at that time. No literature on saphenous nerve conduction tests is available as an indication after knee arthroplasty [7]. No motor deficits were observed in this patient as it is a pure sensory nerve.…”

Infrapatellar Branch of the Saphenous Nerve Injury: Implications for the Physical Therapist

“…Iatrogenic causes are most commonly associated with IBSN injury. Most frequently, surgeries of the knee, such as ACL reconstruction with hamstring or patellar tendon grafting [3,4,21,27,38,43], total knee arthroplasty (TKA) [10,21,23,[43][44][45], and knee arthroscopy [2,21,38,46] have been found to cause injury. Hamstring graft harvesting associated with ACL reconstruction appears particularly troublesome, as incisions for harvesting the semitendinosis tendon must pass close to the where the IBSN emerges between the sartorius and gracilis tendons [4,42,47] Chambers [48] has cautioned surgeons to pay careful attention with medial knee incisions due to the neuroanatomy of the region, though Kerver, et al [49] concede no safe zone truly exists for portal placement.…”

“…Two sequalae of injury are described postoperatively: entrapment [38] and neuroma development [44,45,54,55,56,57]. Entrapment may occur due to misplaced sutures or post-operative scarring.…”

“…Sensory assessment includes palpation and Tinel's tests at key locations; specifically, at the adductor canal and along the medial aspect of the knee by the sartorius tendon proximal to its attachment at the pes anserinus [10,16,19,20,44,45]. These locations describe the transmittance of the primary branch of the saphenous nerve and the IBSN, respectively.…”

Surgical treatment outcome of painful traumatic neuroma of the infrapatellar branch of the saphenous nerve during total knee arthroplasty

“…Although very rare, the development of infrapatellar saphenous neuroma (ISN) is a well-recognized factor of knee pain following not only TKA but also patellar and hamstring tendon harvest during anterior cruciate ligament reconstruction, open and arthroscopic repairs, tibial nailing, and vascular surgery of the lower extremity[ 3 , 4 ]. The prevalence of postoperative infrapatellar branch of the saphenous nerve (IPSN) damage has been reported to range between 0.5 to 53%[ 4 ] and may be apparent up to 9.7% and 21% of patients after primary and revision TKA, respectively[ 5 ], causing neuralgia or hypersensitivity, paresthesia, and loss of sensation at the medial joint area[ 4 ].…”