Clinical Trial Details
— Status: Withdrawn
Administrative data
| NCT number |
NCT02856958 |
| Other study ID # |
16041403 |
| Secondary ID |
|
| Status |
Withdrawn |
| Phase |
N/A
|
| First received |
August 2, 2016 |
| Last updated |
April 9, 2018 |
| Start date |
July 2016 |
| Est. completion date |
July 2017 |
Study information
| Verified date |
April 2018 |
| Source |
Rush University Medical Center |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The purpose of this study is to compare acute nerve decompression versus nonoperative
treatment in the management of peroneal nerve palsy after total knee arthroplasty (TKA). We
hypothesize that acute nerve decompression patients will have better long-term outcomes to
patients treated non-operatively for peroneal nerve palsies after TKA.
Description:
Peroneal nerve palsy after TKA has been reported in the literature to be 0.3% to 1.5%,
although it can be as high as 9.5%. Several risk factors have been described: preoperative
valgus deformity and flexion contracture, prolonged intraoperative use of a tourniquet, use
of epidural anesthesia, and rheumatoid arthritis. Peroneal palsy is rarely diagnosed on
postoperative day 0, but in more than 85% of cases, it presents prior to postoperative day
4.Initial treatment should include flexing the knee, removing any compressive bandages, and
discontinuing epidural anesthesia. When there are residual deficits, supportive measures are
initiated, including application of an ankle-foot orthosis and physical therapy to prevent
ankle contracture. If there is no clinical recovery by six to twelve weeks, electromyography
(EMG) is typically performed. Some clinicians have advocated the use of EMG studies in the
acute phase. In cases of incomplete recovery, delayed surgical exploration and decompression
of the peroneal nerve is an option that has been reported to improve outcomes. Unfortunately,
not all cases respond, even with surgical treatment. In addition, little information is
available describing the outcomes of acute surgical decompression for peroneal nerve palsy
after total knee arthroplasty.
While there have been retrospective case reports and series that have examined outcomes after
delayed peroneal nerve decompression, we are unaware of reports describing acute
decompression. Delayed decompression of the peroneal nerve has been associated with the
return of nerve function. Krackow et al. reported the results of five patients who underwent
delayed surgical decompression for peroneal nerve palsy after total knee arthroplasty at an
average of 27.2 months (range, 5-50 months) and found that 100% were able to discontinue use
of the ankle-foot orthosis and 80% had full neurological recovery. The patient who had
partial return of neurological function did not undergo decompression until almost four years
postoperatively. Mont et al. found that, in patients who underwent surgical peroneal nerve
decompression two to sixty months following total knee arthroplasty, 97% reported functional
and subjective improvements at a mean of three years post-decompression and were able to
discontinue use of the ankle-foot orthosis. Only 33% of the patients who were managed
nonoperatively reported improvement in functional and subjective outcomes.
Therefore, in 33% of the patients, an acute decompression would not have been necessary, but
in the other 67%, it may have been beneficial. In both studies, patients underwent a trial of
nonoperative treatment, and no patient underwent a peroneal nerve decompression earlier than
two months after the index total knee arthroplasty. Initial experience with two peroneal
nerve palsies following TKA has encouraged some institutions to offer acute decompression to
all patients who present with peroneal palsy following total knee arthroplasty. This
parallels the practice patterns regarding the wrist, where an acute carpal tunnel release is
performed to avoid complications when a patient demonstrates carpal tunnel compressive
symptoms postoperatively from wrist surgery. While most patients will improve with
nonoperative treatment over time, acute decompression may accelerate recovery, which can
decrease uncertainty and stress for both the patient and the surgeon. The surgical technique
is relatively straightforward; however, the surgeon and patient must consider the risks of a
second anesthetic and operation. In previous experiences with both acute and delayed
decompression, while direct damage to the nerve itself is rare, fascial bands, hematomas, and
local edema are typically identified that contribute to the compression of the peroneal
nerve. Therefore, while nonoperative treatment would possibly result in a return of nerve
function once the hematoma resorbed and edema decreased, there may still be some residual
dysfunction from the time period of nerve compression and thickened fascial bands around the
nerve. Additional study of acute decompression is warranted to understand if it offers both
short and long-term advantages over nonoperative treatment.
Treatment Groups: Acute Nerve Decompression - patients will initially receive conservative
management (flexing the knee, removing any compressive bandages, and discontinuing epidural
anesthesia) followed by a peroneal nerve decompression within 1 week of diagnosis of peroneal
nerve palsy. Decompression involves surgical intervention in the setting of a sterile
operating room. The patient will be provided with multiple options of anesthesia (per
discussion with the anesthesia team). The surgical procedure involves an incision at the
lateral aspect of the knee, near the proximal fibula at the level of the fibular neck. The
peroneal nerve is carefully identified and dissected. Tissue surrounding or impinging the
nerve is carefully removed or cut to rid the compressive environment. The nerve is re-
examined to ensure there are no additional points of compression/irritation. The soft-tissues
and skin are subsequently closed with suture. Nonoperative Treatment - patients will receive
conservative management (flexing the knee, removing any compressive bandages, and
discontinuing epidural anesthesia) as well as supportive measures (ankle-foot orthosis and
physical therapy) for symptoms lasting longer than 6 week. Outcome Measures: Primary Measure
- ≥ 3/5 dorsiflexion strength 3 months after surgery/randomization
