Association Between Posterolateral Foraminal Osteophyte and Superior Articular Process Hook With Post-Operative Radiculopathy in ALIF.

STUDY

DESIGN

Retrospective cohort study at a single institution.

OBJECTIVE

To determine the incidence of postoperative lumbar radiculopathy (PLR) following single-level anterior lumbar interbody fusion (ALIF) at L4-L5 or L5-S1, evaluate the unplanned return-to-operating-room (UPROR) rate, and assess associations of posterolateral foraminal cephalad endplate osteophytes (PFO) and superior articular process hooks (SAH) with PLR.

SUMMARY OF BACKGROUND DATA: Limited research exists on PLR incidence after ALIF or its association with PFO and SAH, which may contribute to indirect nerve root compression postoperatively.

METHODS

Patients undergoing single-level L4-L5 or L5-S1 ALIF from January 2022 to December 2023 were reviewed, excluding those with spinal deformity, trauma, or infection. PLR was categorized as new, persisting, or worsening. Data included PLR presence, new postoperative weakness, direct decompression history, Bone Morphogenetic Protein-2 (BMP-2) usage, PFO (>50% exiting nerve root width), and SAH (>2 mm foraminal extension) on preoperative imaging. Radiographic parameters, including posterior disc height (PDH), spondylolisthesis, and lordosis at the operative level (L4-L5 or L5-S1), were measured preoperatively and 1-month postoperatively. Pearson chi-square tests assessed associations between PFO, SAH, decompression history, dynamic spondylolisthesis, and PLR. Multivariable logistic regression evaluated these as PLR predictors.

RESULTS

Of 204 patients (mean age, 62.8 y; 51% male), 37 (18.1%) developed PLR. SAH (P=.015) and PFO (P=.001) were significantly associated with PLR in chi-square analyses and remained independent predictors in multivariate regression (SAH: odds ratio [OR], 2.82; P=.017; PFO: OR, 3.25; P=.005). Among PLR patients, 27.0% had new weakness, 43.2% new radiculopathy, 24.3% worsening radiculopathy, and 32.4% persisting radiculopathy (categories not mutually exclusive). Symptoms resolved in 78.4% by 5.9 months (range, 0.07-23.7). UPROR occurred in 18 patients (8.8% total; 48.6% PLR), primarily for decompression (72.2% resolution post-reoperation). Ten patients (27.0%) received epidural steroid injections.

CONCLUSION

PLR occurred in 18.1% of single-level ALIF patients; 78.4% resolved by 6 months. SAH and PFO independently predict PLR, necessitating preoperative evaluation to mitigate complications and reoperation risk.