Management of chronic knee pain caused by postsurgical or posttraumatic neuroma of the infrapatellar branch of the saphenous nerve

Abstract

Purpose: Injury to the infrapatellar branch of the saphenous nerve (IBSN) is a relatively common complication after knee surgery, which can interfere with patient satisfaction and functional outcome. In some cases, injury to the IBSN can lead to formation of a painful neuroma. The purpose of this study was to report the results of surgical treatment in a series of patients with IBSN painful neuroma. Methods: We retrospectively identified 37 patients who underwent resection of IBSN painful neuroma at our institution, after failure of non-operative treatment for a minimum of 6 months. Injury to the IBSN resulted from prior orthopedic surgery, vascular surgery, tumor resection, trauma, or infection. Leg pain and health-related quality of life were measured using the numeric rating scale (NRS) and EuroQol 5 dimensions (EQ-5D) questionnaire, respectively. Clinically meaningful improvement in leg pain was defined as reduction in NRS by at least 3 points. Predictors of favorable and unfavorable surgical outcome were investigated using multivariable logistic regression analysis. Results: Patient-reported leg pain, health-related quality of life, and overall satisfaction with the surgical outcome were obtained at 94 ± 52.9 months after neuroma surgery. Postoperative patient-reported outcomes were available for 25 patients (68% of the cohort), of whom 20 patients (80.0%) reported improvement in leg pain, 17 patients (68.0%) reported clinically meaningful improvement in leg pain, and 17 patients (68%) reported improvement in health-related quality of life. The average NRS pain score improved from 9.43 ± 1.34 to 5.12 ± 3.33 (p < 0.01) and the average EQ-5D functional score improved from 10.48 ± 2.33 to 7.84 ± 2.19 (p < 0.01). Overall patient reported satisfaction with the surgical outcome was good to excellent for 18 patients (72.0%). Older age, multiple prior orthopedic knee surgeries, and failed prior attempts to resect an IBSN neuroma were associated with non-favorable surgical outcome. Conclusion: We conclude that surgical intervention is efficacious for appropriately selected patients suffering from IBSN painful neuroma.