Case #2: Fixed Sagittal Imbalance


Dr. Lawrence LenkeLawrence G. Lenke, MD

  • Professor of Orthopedic Surgery;
  • Chief, Division of Spinal Surgery
  • Director, Spinal Deformity Surgery
  • Co-Director, Adult and Pediatric Comprehensive Spine Surgery Fellowship
  • Columbia University Dept. of Orthopedic Surgery
  • Surgeon-in-Chief, The Spine Hospital, New York-Presbyterian/Allen, New York, NY USA


69 y/o Female with a PMH of degenerative lumbar stenosis who is s/p an L2-L4 XLIF, and a multilevel lumbar decompression and PSF T10-S1. She complains of 75% lower back pain, and 25% lower extremity pain in the bilateral L5 distribution. She also bitterly complains of the inability to stand upright and having to bend her knees and extend her neck to stand, walk and look forward.  She has well controlled hypertension, and is o/w fairly healthy.  She does not smoke and is a social drinker (1-2 drinks/weekend).  She stands with a fixed sagittal imbalance posture with her knees bent and is unable to stand upright. She has well healed posterior and lateral scars. She has a normal dynamic and static neurologic exam to her upper and lower extremities, motor, sensory and reflex inclusive except for trace weakness in her bilateral EHLs, grade 4+/5.  She has good ROM to her hips and knees and good pulses in her feet. She has good ROM to her neck as well.  Her DEXA scan shows a femoral neck T-score of -2.2.


Standing AP (Fig. 1) and lateral (Fig. 2) x-rays of her spine show implants in place from T10 to S1.  No coronal plane deformity.  She has 26 degrees of thoracic kyphosis and no lumbar lordosis – from T12-S1 she actually has 3 degrees of kyphosis.   Sagittal imbalance is positive 20 cm, pelvic incidence of 84 and a pelvic tilt of 66.  She does have an L5-S1 slip.  Her truncal posture is obviously improved on the supine lateral x-ray (Fig. 3).  Full length EOS x-rays show her overall coronal balance is good (Fig. 4) while her lateral x-ray (Fig. 5) shows her fixed sagittal imbalance posture.  Her lumbar sagittal MRI (Fig. 6) shows multilevel degeneration and postoperative changes, also better visualization of the L5-S1 slip.  The 3D CT scan (Fig. 7) shows her implants in place and her flattened lumbar spine and her sagittal 2D CT scan (Fig. 8) shows evidence of loosening of her distal screws.  Her preoperative posterior (Fig. 9) and lateral (Fig. 10) clinical photos demonstrate the necessity to bend her knees so she can stand up straight.

(Click to view images larger)




(Click to view images larger)




Fixed Sagittal Imbalance s/p prior T10-sacrum instrumentation and fusion.


She had a revision PSF T9-Sacrum/Ilium with an extended L5 PSO (Schwab grade 4 osteotomy), an L5-S1 TLIF and an L4-5/L5 intrabody cage placed within her PSO site.  Her SSEPs and TCMEPs were stable throughout and she awoke with slight weakness in her bilateral EHLs (grade 5-/5). EBL: 1200 cc with 500 cc of Cell Saver Blood transfused.


She returned to normal strength in her EHLs by the time she left for Rehab on POD #6. Her hospital course was o/w unremarkable without any postoperative complications. Her Postop X-rays (Figs. 11, 12) show the extension of her implants up to T9 and down to her pelvis and restoration of lumbar lordosis.  Full length lateral EOS x-ray (Fig. 13) and her postoperative clinical photos (Figs. 14, 15) show excellent regional and global alignment.

(Click to view images larger)



(Click to view images larger)




She had bilateral dual S2AI screws placed for sacral-pelvic fixation due to the L5 PSO and a need for 6 fixation points below her PSO.  She had 4 rods placed across her PSO site for stabilization.

Read More: