J Korean Neurosurg Soc.  2016 Nov;59(6):610-614. 10.3340/jkns.2016.59.6.610.

Microsurgical Foraminotomy via Wiltse Paraspinal Approach for Foraminal or Extraforaminal Stenosis at L5-S1 Level : Risk Factor Analysis for Poor Outcome

• Cho SI
• Chough CK
• Choi SC
• Chun JY

• KMID: 2417344
• DOI: http://doi.org/10.3340/jkns.2016.59.6.610

Abstract

OBJECTIVE
The purpose of this study was to present the outcome of the microsurgical foraminotomy via Wiltse paraspinal approach for foraminal or extraforaminal (FEF) stenosis at L5-S1 level. We investigated risk factors associated with poor outcome of microsurgical foraminotomy at L5-S1 level.
METHODS
We analyzed 21 patients who underwent the microsurgical foraminotomy for FEF stenosis at L5-S1 level. To investigate risk factors associated with poor outcome, patients were classified into two groups (success and failure in foraminotomy). Clinical outcomes were assessed by the visual analogue scale (VAS) scores of back and leg pain and Oswestry disability index (ODI). Radiographic parameters including existence of spondylolisthesis, existence and degree of coronal wedging, disc height, foramen height, segmental lordotic angle (SLA) on neutral and dynamic view, segmental range of motion, and global lumbar lordotic angle were investigated.
RESULTS
Postoperative VAS score and ODI improved after foraminotomy. However, there were 7 patients (33%) who had persistent or recurrent leg pain. SLA on neutral and extension radiographic films were significantly associated with the failure in foraminotomy (p<0.05). Receiver-operating characteristics curve analysis revealed the optimal cut-off values of SLA on neutral and extension radiographic films for predicting failure in foraminotomy were 17.3° and 24°s, respectively.
CONCLUSION
Microsurgical foraminotomy for FEF stenosis at L5-S1 level can provide good clinical outcomes in selected patients. Poor outcomes were associated with large SLA on preoperative neutral (>17.3°) and extension radiographic films (>24°).

Keyword

Lumbar vertebrae; Foraminal stenosis; Foraminotomy; L5 root; Lordosis

MeSH Terms

Animals
Constriction, Pathologic*
Factor Analysis, Statistical*
Foraminotomy*
Humans
Leg
Lordosis
Lumbar Vertebrae
Range of Motion, Articular
Risk Factors*
Spondylolisthesis
X-Ray Film

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