Ruling out piriformis syndrome before diagnosing lumbar radiculopathy.
BACKGROUND
Piriformis syndrome (PS), a rare cause of sciatica, is usually diagnosed only after excluding all other possibilities. But this principle is being challenged because of the number of patients with PS who have had ineffective lumbar decompressive surgery after positive findings on image study.


METHODS
From 2001 to 2004, twelve patients with piriformis syndrome diagnosed by physical examination were retrospectively enrolled in this study. Indicators of piriformis syndrome include a positive Freiberg sign and local tenderness over the piriformis tendon. All patients received local injection of triamcinolone acetonide and lidocaine into the piriformis tendon. The course of diagnosis and treatment was reviewed retrospectively from patient records and patient recollections.


RESULTS
Of seven (58.3%) patients who had positive findings on computed tomography (CT) or magnetic resonance imaging (MRI) studies of the lumbar spine, four had previously undergone unsuccessful lumbar surgeries but were responsive to local injection and three received the injection first. Two of those three required no lumbar discectomy thereafter. However, one patient subsequently underwent lumbar decompression surgery because of failed response to the local injection. Three patients had negative CT or MRI findings, and two received no CT or MRI study. According to our diagnostic flowchart for PS, further lumbar surgery was unnecessary for eleven of the twelve patients at follow-up.


CONCLUSIONS
According to experience in this series, a Freiberg test and local injection should be performed first to rule out PS in patients with unilateral sciatica. If symptoms are relieved by local injection and further physical therapy for PS, unnecessary lumbar surgery can be avoided.
Niu
Chi-Chien
CC
Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taipei, Chang Gung University College of Medicine, Taoyuan, Taiwan. niuchien@cgmh.org.tw
Lai
Po-Liang
PL
Fu
Tsai-Sheng
TS
Chen
Lih-Huei
LH
Chen
Wen-Jer
WJ
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011843:Radiculopathy / Q000175:diagnosis*; D012189:Retrospective Studies; D012585:Sciatica / Q000175:diagnosis*; D013577:Syndrome; D014057:Tomography, X-Ray Computed