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Updated: Jan 8, 2026
Surgical Approach and Complications of Stand-alone Lateral Trans-Psoas Interbody Fusion
Published on: February 14, 2025
Does psoas size predict postoperative thigh pain in extreme lateral interbody fusion?
Najim Yusof1, Chang Yi Woon1, Han Xinyun Audrey1
1Orthopaedics Surgery, Singapore General Hospital, Singapore.
Background:
Lateral lumbar interbody fusion via a transpsoas approach is designed to reduce the morbidity of open spinal surgeries and achieve lordosis targets in fusion. A common postoperative finding is thigh dysesthesia and weakness. However, there has not been much research into factors contributing to the thigh dysesthesia and weakness. This study aims to assess the association between psoas size and postoperative thigh and/or groin pain.
Methods:
A prospectively collected retrospectively analyzed database of patients who had degenerative lumbar spinal stenosis who underwent transpsoas lumbar interbody fusion at a single institution was evaluated. We included patients who had XLIF to either L3/4 and/or L4/5 and excluded patients who did not have preoperative MR imaging scans available in our electronic health records. Patients with previous lumbar surgeries and history of infection to the lumbar spine and psoas were excluded. 80 patients met the inclusion criteria. We tested the association between the presence of postoperative thigh and/or groin pain with the following factors: psoas muscle dimension, gender, age, BMI and length of psoas retraction time using One-way ANOVA or Chi-square test or Fisher Exact test where appropriate.
Results:
A total of 80 patients met the inclusion criteria. Anterior-posterior diameter of the psoas (p = .011-.013) was found to have a statistically significant relationship with postoperative thigh and/or groin pain for patients who underwent transpsoas lumbar interbody fusion at multiple levels.
Conclusions:
When considering patients for multilevel lateral lumbar spine surgery, MRI evaluation of anterior-posterior diameter of psoas size and gender of patient is helpful in predicting cases with higher risk of developing postoperative thigh pain. When anterior-posterior psoas diameter is more than 49.51 mm (for multiple level surgeries), consideration to approach via an anterior to psoas lateral approach or greater discussion with postoperative expectation would be warranted.
