Neurologic Complications in Spinal Deformity Surgery

Although the incidence of complications in patients undergoing correction of their spinal deformity has been reported extensively, the majority of these studies were retrospective. There were only five studies, three from a single institution, with prospectively collected data that specifically identified complications. The largest series was from Buchowski et al who reported on 108 patients with fixed sagittal deformity undergoing Pedicle Subtraction Osteotomy (PSO) with a 14% over-all complication rate with motor weakness in 11 patients and neurogenic bladder in one patient, of which 3 were permanent. Yang reported on 35 patients undergoing PSOs with a 46% over-all complication rate and one transient nerve root motor deficit. Ahn in 2002 reported on 83 patients undergoing various osteotomies for sagittal imbalance and reported a 34% over-all complication rate with 3 permanent and 3 transient nerve root deficits.

Given this lack of information, there is a need to determine the true incidence of complications using a prospective multi-center design. There is a need to identify neurologic deficits in a more systematic fashion to include spinal cord, cauda equina and nerve root deficits as well as radiculopathies. The risk factors associated with the occurrence of a complication, especially a neurologic complication, also needs to be more fully elucidated. This is increasingly relevant, as newer surgical techniques allow for more aggressive correction of the spinal deformity that may put the spinal cord and nerve roots at increased risk. Valid data on the incidence and types of neurologic deficits is also needed in order to study newer drugs that are available that may mitigate this risk.

The primary objectives of this study are: (i) to establish the incidence of neurologic deficit in "high risk" adult patients undergoing correction of their spinal deformity of adult spinal deformity and (ii) to identify characteristics associated with increased risk of neurologic complications. Secondary objectives include (i) to determine the incidence of all complications related to surgical correction of "high risk" adult spinal deformity; (ii) to determine the short-term clinical outcomes in patients undergoing correction of their spinal deformity and (iii).to determine amount of radiographic and clinical correction of deformity

Inclusion criteria

• Signed informed consent
• Age 18 to 80 years old inclusive
• Diagnosis of adult spinal deformity with an apex of the major deformity in the cervico-thoracic or thoraco-lumbar region (Apex between C7 and L2 inclusive) with any of the following deformity characteristics

• Primary Scoliosis, Kyphosis or Kyphoscoliosis with major Cobb ≥ 80° in the coronal or sagittal plane
• Congenital Spinal Deformity undergoing corrective spinal osteotomy
• Revision Spinal Deformity undergoing corrective spinal osteotomy
• Any patient undergoing a 3-column spinal osteotomy (i.e. Pedicle Subtraction Osteotomy, Vertebral Column Resection) from C7 to L5 inclusive
• Any patient with preoperative myelopathy due to their spinal deformity
• Any patient with ossification of the Ligamentum Flavum or Posterior Longitudinal Ligament and a deformity that needs concomitant reconstruction along with decompression of the spinal cord

Exclusion criteria

• Unlikely to comply with follow-up
• Recent history ≤ 3 months of substance dependency or psychosocial disturbance
• Presence of active malignancy
• Has active, overt bacterial infection, systemic or local
• Recent (≤3 months) history of significant spinal trauma/injury/ fracture/malignancy in the spinal region
• Patients with complete, long term paraplegia
• Pregnant or nursing women, unable to agree not to become pregnant for a period of 6 months after surgery
• Prisoners
• Institutionalized individuals