Results of Lumbar Pedicle Subtraction Osteotomies for Fixed Sagittal Imbalance: A Minimum 5-Years Follow-Up Study

Method: Thirty-four consecutive patients with sagittal imbalance (28 females/ 6 males, average age at surgery 53 years) treated with lumbar pedicle subtraction osteotomies (1 L1, 13 L2, and 20 L3) at one institution were analyzed (average follow-up 5.8 years, range 5-7.6 years). Radiographic analysis including various sagittal parameters and clinical outcomes analysis using Oswestry questionnaire and the Scoliosis Research Society questionnaire was performed.

Results: There were no significant radiographic changes between the 2 years postoperation and the ultimate follow-up (the average lumbar lordosis 43 at 2 years postoperation à 45 at ultimate follow-up and the sagittal vertical axis 4.4cm at 2 years postoperation à 5.3cm at ultimate follow-up). There was no degradation in Oswestry score (2 years postoperation 13 + 8.4 and ultimate follow-up 10 + 8.0) and SRS outcome score (74% at 2 years postoperation and 74% at ultimate follow-up). Patients reported good self-image (74% at 2yrs postoperation and 85% at ultimate follow-up), good satisfaction (91% at 2yrs postoperation and 85% at ultimate follow-up), moderate pain (68% at 2yrs postoperation and 64% at ultimate follow-up), and function (64% at 2yrs postoperation and 67% at ultimate follow-up) subscales. Among 10 pseudarthroses (29%) in 8 patients, 5 pseudos developed 2-4 years postoperation (no pseudo after 4 years postoperation). There was no pseudarthrosis at the osteotomy level (8 pseudos at TL junction and 2 at LS junction), but at the levels added to the previous fusions.

Conclusion: There were no significant radiographic and clinical outcome changes between the 2 years and the 5 to 8 years postoperation following lumbar pedicle subtraction osteotomy for fixed sagittal imbalance.

Hibbs Award Nominee for Best Clinical Paper