Anterior lumbar interbody fusion (ALIF): biometrical results and own experiences

Abstract

Lumbar fusion is a mainstay in the treatment of low back pain resulting from degenerative disc disease. Anterior lumbar interbody fusion (ALIF) has become a reasonable treatment technique to achieve indirect foraminal decompression with high fusion rates. The aim of the study was to analyse the biometrical parameters of the lumbar spine and the clinical outcome. The medical records of 51 patients treated with ALIF between 2012 and 2016 were retrospectively reviewed. Anterior and posterior disc height (DH), lumbar lordosis (LL), local disc angle (LDA) and foraminal dimensions were obtained on pre- and postoperative plain radiographs and computed tomography scans using ImageJ and Surgimap software according to the pedicle-pedicle technique. To evaluate the interbody fusion status on the last follow-up CT scans, we used Bridwell criteria. Preoperative and 12 months postoperative Oswestry Disability Index (ODI) scores were determined for all patients. The average length of hospitalisation was 4 days. Most of the patients had degenerative disc disease with foraminal stenosis. Five patients had early complications like paresthesia of lower limbs, sympathetic dysfunction or wound infections, but there were no major complications. Statistically significant (P < .01) improvement was observed in foraminal dimensions (area = 49%, height = 33% and width = 19%), anterior DH (49%), posterior DH (69%), LDA (47%) and LL (17.5%). Posterior DH correlated significantly with foramen height improvement. Radiographic evidence of fusion according to the modified Bridwell criteria (grade I and grade II) was observed in 96% (49/51) of the patients in the last CT of the lumbar spine. We also observed significant improvement in functional recovery in 94% of patients. The mini-open ALIF approach is a reasonable alternative to the more extensive posterior approaches. ALIF significantly restores the height of the intervertebral disc, indirectly increases foraminal dimensions, increases lordosis angle with significant short and long-term pain relief and functional recovery.

Keywords: Anterior lumbar interbody fusion; Degenerative disc disease; Foramen measurement; Indirect decompression; Lumbar spine surgery.

Fig. 1

Preoperative and postoperative changes in neural foramen dimensions—foramen height (FH), foramen width (FW) and area of the foramen (FA) calculated on CT scans with P-P technique

Fig. 2

Postoperative changes in midline dimensions. On the left ADH—anterior disc height, PDH—posterior disc height, LDA—local disc angle, on the right L1-S1 lumbar lordosis obtained with Cobb method

Fig. 3

Graph showing improvements in the Oswestry Disability Index scores in patients (P < 0.01)

Fig. 4

Graph showing improvements in the foraminal dimensions in patients after ALIF surgery (P < 0.01)