Journal de la colonne vertébrale

Non-Posterior Subtraction Osteotomy Surgery to Restore Lumbar Lordosis in the Hidden Sagittal Imbalance of the Adult Degenerative Spine

Abstract

Alessandro Ramieri, Massimo Miscusi, Filippo Maria Polli, Antonino Raco and Giuseppe Costanzo

Purpose: Sagittal imbalance of severe adult degenerative deformities requires surgical correction to improve pain, mobility and quality of life. Our aim was a harmonic and balanced spine, treating a series of adult degenerative kyphoscoliosis by a nonposterior subtraction osteotomy technique. Extreme lateral (XLIF) and transforaminal (TLIF) interbody fusion were used to restore lumbar lordosis and mobilize the coronal curve, while grade 2 osteotomy (SPO) was useful to further decrease kyphosis.

Methods: We operated 22 thoraco-lumbar and lumbar degenerative deformities, characterized by a sagittal compensated (hidden) imbalance (SVA<50 mm), with or without coronal deformity, and distinguished according to the SRS-Schwab classification. All patients were submitted to X-ray screening during pre, post-operative and follow-up periods.

Results: Mean age was 65.3 (50-74; M/F 1: 4). Sixteen deformities were type L and 6 type N. Loss of LL was moderate (+) in 14 cases and marked (++) in 8. We performed 39 XLIFs, 8 TLIFs, 32 SPOs. Complication rate was minimal. Pelvic tilt, lumbar lordosis, sagittal vertical axis and thoracic kyphosis improved (p<0.05), post-operative values were similar to those pre-operatively calculated in 90% of cases and clinical follow-up (mean 20.5; range 18- 24), scored using VAS and ODI, was satisfactory in all cases, except for two due to sacro-iliac pain.

Conclusion: Current follow-up does not allow definitive conclusions. However, the surgical approach reported seems to be a viable choice usable in these compensated adult deformities, avoiding risks and complications of more aggressive pedicle subtraction osteotomies.