This week’s Case Debate Series, hosted by NuVasive, Inc., features a spirited debate regarding the preferred thoracolumbar procedure approach: anterior or posterior? Dr. Joey Laratta, orthopedic surgeon at Norton Letterman Spine Center, argues on behalf of the anterior-approach, highlighting minimally invasive anterior based surgery for adult degenerative scoliosis patients, and Dr. Avery Buchholz, neurosurgeon at University of Virginia, presents the argument in support of the posterior approach, highlighting posterior-only surgery for the same patient population. Today’s moderator is Dr. Reg Haid of Atlanta Brain and Spine Care.
Moderator Haid: It is an honor to moderate the first Case Debate hosted by NuVasive. This is the first debate in our series and it will compare anterior with posterior thoracolumbar approaches for degenerative scoliosis.
Let’s start with Dr. Laratta.
Dr. Laratta: Thank you for the introduction. We’re going to be talking about thoracolumbar procedural approaches and I am taking the side of anterior approaches. There’s been a transition from all posterior approaches, the way I was trained in residency, towards the anterior column, and the importance of anterior interbody support.
My patient is a 62-year-old female with a significant back pain. She can’t walk long distances, and feels like she’s leaning forward, which seems like a sagittal imbalance problem. She failed extensive nonoperative treatment. She’s a non-smoker and has compensatory mechanisms. When we look at her 36-inch sagittal, I see a mismatch of 51 degrees, pelvic retroversion with a pelvic tilt of 38 degrees, and lumbar lordosis of essentially zero. On her AP radiograph, she has a coronal Cobb angle of 43 degrees and two centimeters. We understand compensatory mechanisms of patients with sagittal imbalance and how these mechanisms relate to the Dubousset cone of economy. However, we plan our surgeries all from a single standing 36-inch film.
I reevaluate after having the patient walk for 5 to 10 minutes to unmask hidden sagittal imbalance in someone who has a compensated deformity. On the 36-inch lateral, she has poor parameters in terms of her pelvic retroversion, but she’s globally compensated. Her SVA [sagittal vertical axis] is only five, but after walking her pelvic and spinal extensor muscles start to fatigue, unmasking hidden decompensation.
I use a coronal CT to plan from which side I’m going to approach. The patient is relatively fused on the right side at L2-3. Anterior fusion through the disc space, which in my hands is relatively difficult to correct posteriorly, is straightforward to correct with these minimal access lateral techniques.
I indicated a multi-level ALIF with an ACR at L3-4 for this patient. The surgery was a T10 to pelvis posterior fixation staged after a multi-level LLIF, anteriorly. Once you do those osteotomies in the back after you’ve released laterally the spine falls exactly where you want it.
We achieved correction of her coronal alignment and harmonious correction of her sagittal alignment.
LLIF [lateral lumbar interbody fusion] really allows for powerful coronal correction and we can limit the amount of bone morphogenetic protein (BMP) that we use by having interbody support at most levels.
Cages, like the Modulus, have a high coefficient of static friction, which allows for early, strong, apophyseal fixation that obviates the need for these multiple rod constructs that we use with all-posterior techniques.
