What are the biggest innovations in spinal deformity care in the last 5 to 10 years?

Dr. Jeremy Smith, Orthopadic Spine Surgeon with Hoag Orthopedic Institute was recently asked to participate in a Becker's Spine Review online article which asked six spine surgeons from across the United States about what the most clinically relevant spinal deformity care innovations have taken place over the past 10 years.

Here is Dr. Jeremy Smith's response:

Over the past decade advances in the treatment of spinal deformity have allowed surgeons to address more complex sagittal and coronal curvatures more accurately, safely, and reproducibly. Although the underlying goal of surgery (deformity correction and arthrodesis) remain the same, some pivotal changes in the diagnostic workup, preoperative preparation and surgical technique have improved outcomes and overall made deformity surgery far less dire.

Traditionally the focus on scoliosis correction has been based on improving deformities in the coronal plane. A surgical correction did not take into account sagittal plane deformities as coronal curvatures display a more profound clinical presentation (rib hump, pelvic or shoulder obliquity). More recent data support the importance of the sagittal plane as being a greater influence on morbidity, outcome and disability. Addressing a global sagittal alignment has proven more effective in improving all outcomes associated with surgery. Furthermore, the definition of a patients intended sagittal parameters (lumbar lordosis, thoracic kyphosis and sagittal vertical axis) has been well defined as it relates to pelvic alignment. The pelvic incidence, a static parameter that does not change during a lifetime, determines the necessary lumbar lordosis needed to maintain global sagittal alignment. With these parameter definitions in place, defining the necessary sagittal plane correction to reproduce sound biomechanics and an optimal surgical outcomes has become very objective. Adhering to these principles have significantly improved radiographic and clinical outcomes and diagnostically utilize traditional radiographic imaging

In line with maintaining global sagittal alignment principles, it is important to take the entire musculoskeletal system into account when addressing compensatory measures that allow a patient to remain clinically balanced. Hip and knee flexion is an important variable that may indirectly influence balance. Pathologies that influence these compensatory variables also have to be addressed (flexion contractures, hip/knee degenerative joint disease). Traditional radiographs essentially ignore these factors and without a keen clinical diagnostic sense these influences are often not accounted for. Fortunately, imaging systems that are looking at the entire patient in a standing position make these influences difficult to ignore. The EOS imaging system enables the surgeon to account for all of these parameters by imaging the entire body in an upright position. The system visualizes the patient in a true physiologic upright standing position and gives a clear sense of balance and the multiple variables that are contributing.

In order to correct a deformity it is critical that the surgeon recognize it and all influences within the musculoskeletal system. This includes understanding how much correction is necessary. The aforementioned diagnostic breakthroughs have allowed the surgeon to do this with significant accuracy. The traditional methods of correction, particularly in the sagittal plane, often involve rather invasive surgical techniques that are inaccurate, morbid and technically difficult. The osteotomy is the cornerstone of correction and involves removing posterior bone and often shortening the spinal column. These surgeries are considered the most technically challenging and are often performed by surgeons trained specifically in spinal deformity. Complications are commonplace and often expected in these procedures ranging from acute blood loss to catastrophic neurologic compromise. They often lead to extended hospital stay and a lengthy recovery. Along with the pelvic parameter influence and global sagittal alignment principles came the reintroduction of anterior segmental correction using interbody grafting techniques. The so-called anterior column realignment surgery involves standard anterior discectomy techniques that allow for powerful segmental lordosis correction. Angled grafts ranging from 15 to 30 degrees can achieve a correction similar to that of an osteotomy with far less morbidity, blood loss, hospital stay and recovery. Having this technique and applying sagittal alignment principles allows a surgeon to treat nearly every spinal reconstruction surgery as a deformity thus removing some of the iatrogenic flatback deformities from being a prominent issue.