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