This article is more than 5 years old. Information may no longer be current.
A 48-year-old woman with right knee pain
Click Here to Manage Email Alerts
A 48-year-old woman with a history of hypertension, rheumatoid arthritis treated with chronic prednisone, and a two-pack-per-week cigarette use, presented to clinic with 8 years of right knee pain. She had an intra-articular steroid injection with some relief 6 years ago. She denied any hip pain and uses a cane for ambulation. On physical examination she appears to be a healthy 5’2’’, 160-pound woman who walks with an antalgic gait. She has a 20° flexion contracture, with flexion limited to 90°, and a mild valgus deformity of her knee. The extremity was neurovascularly intact and she had full, painless hip range of motion.
Plain radiographs of the right knee (Figure 1) showed severe degenerative joint disease. The decision was made to proceed with a right total knee arthroplasty (TKA).
The patient underwent an uncomplicated TKA and intraoperatively full extension was achieved with a posterior capsular release (Figure 2). In the initial postoperative period and the following morning, she was neurovascularly intact. However, throughout the first postoperative day, the patient developed numbness on the dorsum of her foot and weakness (three of five strength) to great toe extension and ankle dorsiflexion.
What is your diagnosis?
See answer on next page.
This preoperative radiograph demonstrates degenerative changes to the patient’s knee.
This postoperative radiograph shows the completed total knee arthroplasty.
Images: Della Valle CJ
Peroneal neuropathy
This patient has peroneal neuropathy following TKA. Although this is a rare complication occurring in roughly 1% of patients, this patient did have some risk factors that have been reported in the literature including rheumatoid arthritis, preoperative flexion contracture and a valgus deformity. Tobacco use also could potentially contribute to neuropathy.
Acutely, the dressings were loosened and patient’s knee was flexed. The flexion seemed to alleviate most of the symptoms; however, her motor function did not improve. One option in this setting is close observation, with a number of studies demonstrating success with nonoperative treatment. Park and colleagues reported on 37 patients with peroneal nerve palsy after TKA that was treated nonoperatively. At a mean 30.1-month follow-up (range 2.1 years to 9.8 years), all patients fully or partially recovered. Schinsky and colleagues also demonstrated similar good results in 19 patients treated nonoperatively. By 18 months of follow-up, 13 patients (68%) showed full recovery and six (32%) had partial recovery.
In contrast, Asp and Rand reported a mean 5-year follow-up on 26 peroneal nerve palsy patients after TKA and only 50% had full recovery. Idusuyi and Morrey and colleagues also showed only a 50% recovery rate in 32 patients with peroneal nerve palsy after TKA at an average follow-up of 46 months. Rose and colleagues reported on 23 peroneal nerve palsies in 22 patients after TKA. At an average 3.1-year follow-up, only 28.6% of patients had motor deficits that fully resolved, and no patient had full resolution of their sensory deficits.
Rachel M. Frank
Nicholas Brown
Given the variability of outcomes with nonoperative treatment, another option is surgical decompression. A few studies have shown good results with this treatment method. Zywiel and colleagues described 11 patients who underwent peroneal nerve decompression following TKA for symptoms of peroneal nerve dysfunction including limited knee range of motion, pain, and decreased sensation. All patients’ symptoms significantly improved after decompression. Krackow and colleagues reported on five patients with peroneal nerve palsy decompressed between 4 months and 45 months following TKA. Four patients had full recovery, one had partial recovery and all patients were able to discontinue the use of their ankle foot orthosis.
Treatment of our patient
Although the patient’s symptoms resolved with knee flexion, given her preoperative flexion contracture, the patient and the surgical team decided to pursue surgical decompression of the peroneal nerve to optimize her ability to attain full extension postoperatively. Briefly, decompression was performed using an 8-cm to 10-cm curvilinear incision along the path of the peroneal nerve. Dissection proceeded through the superficial soft tissue, the deep fascia was split, and the peroneal nerve was freed both proximally and distally.
The decompression was performed on postoperative day 4, and the patient tolerated the procedure well. The patient had immediate improvement of her motor strength in the recovery room (four out of five strength) with full resolution of symptoms and full motor strength by the time of her 2-week postoperative visit.
References:
Asp JP, et al. Clin Orthop Relat Res. 1990;261:233-237.
Bryan RS, et al. Clin Orthop Relat Res. 1973;(94):148-152.
Idusuyi OB, et al. 78:2 J Bone Joint Surg. 1996;78:177-184.
Knutson K, et al. Scand J Rheumatol.1983;12(3):201-205.
Krackow KA, et al. Clin Orthop Relat Res. 1993;(292):223-228.
Lang AH, et al. Scand J Rheumatol. 1981;10(2):81-84.
Park JH, et al. J Arthroplasty. 2013;doi:10.1016/j.arth.2013.02.025.
Rose HA, et al. J Bone Joint Surg. 1982;64(3):347-351.
Schinsky MF, et al. J Arthroplasty. 2001;16(8):1048-1054.
Sivri A, et al. Electromyogr Clin Neurophysiol. 1999;39(7):387-391.
Zywiel MG, et al. J Arthroplasty. 2011;doi:10.1016/j.arth.2010.03.020.
For more information:
Nicholas M. Brown, MD; Rachel M. Frank, MD; John Fernandez, MD; and Craig J. Della Valle, MD, can be reached at Rush University Medical Center, 1611 W. Harrison, Ste. 300, Chicago, IL 60612; Brown’s email: nmb2116@gmail.com; Frank’s email: rmfrank3@gmail.com; Fernandez’s email: john.fernandez@rushortho.com. Della Valle’s email: craigdv@yahoo.com.
Disclosures: Frank and Brown report no relevant financial disclosures. Fernandez has stock or stock options and IP royalties from Tornier. Della Valle is a consultant for Biomet, DePuy and Smith & Nephew; receives royalties from DePuy; research support from Biomet, CD Diagnostics, Smith & Nephew and Stryker; and has stock and options in CD Diagnostics.