Relationship between degree of focal kyphosis correction and neurological outcomes for patients undergoing cervical deformity correction surgery

Abstract

Object Reversal of the normal cervical spine curvature, as seen in cervical kyphosis, can lead to mechanical pain, neurological dysfunction, and functional disabilities. Surgical intervention is warranted in patients with sufficiently symptomatic deformities in an attempt to correct the deformed cervical spine. In theory, improved outcomes should accompany a greater degree of correction toward lordosis, although there are few data available to test this relationship. The purpose of this study is to determine if the degree of deformity correction correlates with improvement in neurological symptoms following surgery for cervical kyphotic deformity. Methods A retrospective review of 36 patients with myelopathic symptoms who underwent cervical deformity correction surgery between 2001 and 2009 was performed. Preoperative and postoperative radiographic findings related to the degree of kyphosis were collected and compared with functional outcome measures. The minimum follow-up time was 2 years. Results A significant relationship was observed between a greater degree of focal kyphosis correction and improved neurological outcomes according to the modified Japanese Orthopaedic Association (mJOA) score (r = −0.46, p = 0.032). For patients with severe neurological symptoms (mJOA score < 12) a trend toward improved outcomes with greater global kyphosis correction was observed (r = −0.56, p = 0.057). Patients with an mJOA score less than 16 who attained lordosis postoperatively had a significantly greater improvement in total mJOA score than patients who maintained a kyphotic position (achieved lordosis: 2.7 ± 2.0 vs maintained kyphosis: 1.1 ± 2.1, p = 0.044). Conclusions The authors' results suggest that the degree of correction of focal kyphosis deformity correlates with improved neurological outcomes. The authors also saw a positive relationship between attainment of global lordosis and improved mJOA scores. With consideration for the risks involved in correction surgery, this information can be used to help guide surgical strategy decision making.

Radiographic Alignment of Cervical Spine on a Sample of Asymptomatic Subjects

“…Several publications have shown a correlation between deformity of the cervical spine and pain and functional disability, in addition to the intensity of the neurological deficit in patients with myelopathy. [14][15][16][17][18] Until now, no criteria have been defined for an indication of corrective surgery for spinal deformity, nor is there any standardization of the objectives of correction of deformity. 1 Recently, a classification system for cervical spine deformity was published, 19 considering the type of deformity and presenting modifiers, including three radiographic parameters, in addition to the severity of the myelopathy and the SRS-Schwab classification of adult deformity types.…”

Association between preoperative cervical sagittal deformity and inferior outcomes at 2-year follow-up in patients with adult thoracolumbar deformity: analysis of 182 patients

“…Cervical malalignment is debilitating and has adverse effects on the overall functioning and health-related quality of life (HRQOL) of the patient. 7,12,22,24,27,29 Tang and colleagues 27 investigated cervical positive sagittal malalignment (CPSM) and disability following posterior cervical fusion in 113 patients. The authors found that increasing CPSM correlates with increasing disability and determined a CPSM threshold of 4 cm, at which severe disability occurs.…”

Delayed Neurologic Deficit after Thoracolumbar Kyphosis Correction: One Case Report

“…Postoperative hypotension has been proved as one direct reason of delayed cord dysfunction due to lowering tissue perfusion [5]. A great degree of kyphosis correction is also associated with late postoperative neurologic complication, for this may induce foraminal stenosis, enhance posterior drift or distraction of spinal cord [6,7]. Previous studies have indicated that patients with sagittal deformities, especially hyperkyphosis are at higher risks of neurologic deficits [8,9].…”