Kai-Ming Fu

Improvement of back pain with operative and nonoperative treatment in adults with scoliosis.

OBJECTIVEThe purpose of this study was to assess whether back pain is improved with surgical treatment compared with nonoperative management in adults with scoliosis. METHODSThis is a retrospective review of a prospective, multicentered database of adults with spinal deformity. At the time of enrollment and follow-up, patients completed standardized questionnaires, including the Oswestry Disability Index (ODI) and Scoliosis Research Society 22 questionnaire (SRS-22), and assessment of back pain using a numeric rating scale (NRS) score, with 0 and 10 corresponding to no and maximal pain, respectively. The initial plan for surgical or nonoperative treatment was made at the time of enrollment. RESULTSOf 317 patients with back pain, 147 (46%) were managed surgically. Compared with patients managed nonoperatively, operative patients had higher baseline mean NRS scores for back pain (6.3 versus 4.8; P < 0.001), higher mean ODI scores (35 versus 26; P < 0.001), and lower mean SRS-22 scores (3.1 versus 3.4; P < 0.001). At the time of the 2-year follow-up evaluation, nonoperatively managed patients did not have significant change in the NRS score for back pain (P = 0.9), ODI (P = 0.7), or SRS-22 (P = 0.9). In contrast, at the 2-year follow-up evaluation, surgically treated patients had significant improvement in the mean NRS score for back pain (6.3 to 2.6; P < 0.001), ODI score (35 to 20; P < 0.001), and SRS-22 score (3.1 to 3.8; P < 0.001). Compared with nonoperatively treated patients, at the time of the 2-year follow-up evaluation, operatively treated patients had a lower NRS score for back pain (P < 0.001) and ODI (P = 0.001), and higher SRS-22 (P < 0.001). CONCLUSIONSDespite having started with significantly greater back pain and disability and worse health status, surgically treated patients had significantly less back pain and disability and improved health status compared with nonoperatively treated patients at the time of the 2-year follow-up evaluation. Compared with nonoperative treatment, surgery can offer significant improvement of back pain for adults with scoliosis.

Incidence of symptomatic hemorrhage after stereotactic electrode placement

OBJECT Intracranial hemorrhage (ICH) is the most significant complication associated with the placement of stereotactic intracerebral electrodes. Previous reports have suggested that hypertension and the use of microelectrode recording (MER) are risk factors for cerebral hemorrhage. The authors evaluated the incidence of symptomatic ICH in a large cohort of patients with various diseases treated with stereotactic electrode placement. They examined the effect of comorbidities on the risk of ICH and independently assessed the risks associated with age, sex, use of MER, diagnosis, target location, hypertension, and previous use of anticoagulant medications. The authors also evaluated the effect of hemorrhage on length of hospital stay and discharge disposition. METHODS Between 1991 and 2005, 567 electrodes were placed by two neurosurgeons during 337 procedures in 259 patients. Deep brain stimulation (DBS) was performed in 167 procedures, radiofrequency lesioning (RFL) of subcortical structures in 74, and depth electrodes were used in 96 procedures in patients with epilepsy. Electrodes were grouped according to target, patient diagnosis, use of MER, patient history of hypertension, and patient prior use of anticoagulant medication (stopped 10 days before surgery). The Charlson Comorbidity Index (CCI) was used to evaluate the effect of comorbidities. The CCI score, patient age, length of hospital stay, and discharge status were continuous variables. Symptomatic hemorrhages were grouped as transient or leading to permanent neurological deficits. RESULTS The risk of hemorrhage leading to permanent neurological deficits in this study was 0.7%, and the risk of symptomatic hemorrhage was 1.2%. A patient history of hypertension was the most significant factor associated with hemorrhage (p = 0.007). Older age, male sex, and a diagnosis of Parkinson disease (PD) were also significantly associated with hemorrhage (p = 0.01, 0.04, 0.007, respectively). High CCI scores, specific target locations, and prior use of anticoagulant therapy were not associated with an increased risk of hemorrhage. The use of MER was not found to be correlated with an increased hemorrhage rate (p = 0.34); however, the number of hemorrhages in the patients who underwent DBS was insufficient to draw definitive conclusions. The mean length of stay for the DBS, RFL, and depth electrode patient groups was 2.9, 2.6, and 11.0 days, respectively. For patients who received DBS and RFL, the mean duration of hospitalization in cases of symptomatic hemorrhage was 8.2 days compared with 2.7 days in those without hemorrhaging (p < 0.0001). Three of the seven patients with symptomatic hemorrhages were discharged home. CONCLUSIONS The placement of stereotactic electrodes is generally safe, with a symptomatic hemorrhage rate of 1.2%, and a 0.7% rate of permanent neurological deficit. Consistent with prior reports, this study confirms that hypertension is a significant risk factor for hemorrhage. Age, male sex, and diagnosis of PD were also significant risk factors. Patients with symptomatic hemorrhage had longer hospital stays and were less likely to be discharged home.

Cortical and subcortical brain shift during stereotactic procedures

OBJECT The success of stereotactic surgery depends upon accuracy. Tissue deformation, or brain shift, can result in clinically significant errors. The authors measured cortical and subcortical brain shift during stereotactic surgery and assessed several variables that may affect it. METHODS Preoperative and postoperative magnetic resonance imaging volumes were fused and 3D vectors of deviation were calculated for the anterior commissure (AC), posterior commissure (PC), and frontal cortex. Potential preoperative (age, diagnosis, and ventricular volume), intraoperative (stereotactic target, penetration of ventricles, and duration of surgery), and postoperative (volume of pneumocephalus) variables were analyzed and correlated with cortical (frontal cortex) and subcortical (AC, PC) deviations. RESULTS Of 66 cases, nine showed a shift of the AC by more than 1.5 mm, and five by more than 2.0 mm. The largest AC shift was 5.67 mm. Deviation in the x, y, and z dimensions for each case was determined, and most of the cortical and subcortical shift occurred in the posterior direction. The mean 3D vector deviations for frontal cortex, AC, and PC were 3.5 +/- 2.0, 1.0 +/- 0.8, and 0.7 +/- 0.5 mm, respectively. The mean change in AC-PC length was -0.2 +/- -0.9 mm (range -4.28 to 1.66 mm). The volume of postoperative pneumocephalus, assumed to represent cerebrospinal fluid (CSF) loss, was significantly correlated with shift of the frontal cortex (r = 0.640, 64 degrees of freedom, p < 0.001) and even more strongly with shift of the AC (r = 0.754, p < 0.001). No other factors were significantly correlated with AC shift. Interestingly, penetration of the ventricles during electrode insertion, whether unilateral or bilateral, did not affect volume of pneumocephalus. CONCLUSIONS Cortical and subcortical brain shift occurs during stereotactic surgery as a direct function of the volume of pneumocephalus, which probably reflects the volume of CSF that is lost. Clinically significant shifts appear to be uncommon, but stereotactic surgeons should be vigilant in preventing CSF loss.

Radiographic restoration of lumbar alignment after transforaminal lumbar interbody fusion.

OBJECTIVERestoration of lumbar lordosis is a critical factor in long-term success after lumbar fusions. Transforaminal lumbar interbody fusion (TLIF) is a popular surgical technique in the lumbar spine, but few data exist on change in spinal alignment after the procedure. METHODSEighty patients who underwent TLIF surgery were retrospectively reviewed (minimum follow-up period, 2 years). Standing x-rays were assessed for changes in focal and segmental kyphosis, and restoration of lumbar lordosis. Improvement in spondylolisthesis, sagittal balance, and scoliosis were also assessed. Fusion was assessed as well. RESULTSEighty operations were performed at 107 levels. Mean presenting lumbar Cobb angle measurement (L1–S1) was 36.3 ± 4.5 degrees (range, 12–77 degrees). Forty patients (50%) had sagittal imbalance. Mean postoperative Cobb angle (L1–S1) was 55.1 ± 6.6. Thirty-three of 36 patients with segmental kyphosis (92%) had restoration of lordosis. Improvement in alignment was most prominent at the surgical level (mean increase in lordosis, 20.2 ± 4.2 degrees). The improvement in lumbar lordosis among patients undergoing multilevel TLIFs (27.3 ± 3.4 degrees) was significantly higher compared with patients undergoing single-level operations (17.4 ± 4.4) (Students t test, P = 0.0004). Thirty of the 40 patients with sagittal imbalance (75%) achieved immediate restoration of normal sagittal balance. The ability to restore normal sagittal balance was correlated with a sagittal imbalance of less than 10 cm (P = 0.0001). Spondylolisthesis was completely corrected at the TLIF site in 90 of 99 levels (91%). Three patients (4%) required reoperation, 2 for implant disengagement and 1 for worsening kyphoscoliosis above the original surgical levels. Two of the 80 patients had pseudoarthrosis; hence, the rate of pseudoarthrosis was 2.5%. CONCLUSIONThe TLIF operation is highly effective in improving spinal alignment in patients with degenerative spinal disorders when the appropriate surgical technique is implemented.

Neurological symptoms and deficits in adults with scoliosis who present to a surgical clinic: incidence and association with the choice of operative versus nonoperative management.

OBJECT Adults with scoliosis often present with neurological symptoms and deficits. However, the incidence of these findings and how they may affect treatment decisions have not been clearly defined. The purpose of this study was to quantify the prevalence of neurological symptoms and deficits in adults with scoliosis presenting to a surgical clinic, and to assess for an association between these factors and the decision to pursue operative treatment. METHODS In this study, the authors document the Oswestry Disability Index (ODI), radiographic findings, and the incidences of back pain, neurological symptoms (radiculopathy and claudication), and neurological deficits (weakness, myelopathy, and bowel/bladder dysfunction) and correlate these with operative versus nonoperative management. Pain was assessed using the visual analog scale (VAS) score. Of 207 patients, 25% underwent surgery. RESULTS Incidences of back pain (VAS score > 0 points) and radiculopathy (VAS score > 0) were 99 and 85%, respectively. The incidences of severe (VAS score > 5) back pain and radiculopathy were 66 and 47%, respectively. Neurological symptoms and deficits included weakness in 8% of patients, claudication in 9%, myelopathy in 1%, and bowel/bladder dysfunction in 3%. Patients with severe radiculopathy had greater mean ODI scores (p < 0.001) and reduced lumbar lordosis (p = 0.04) and were more likely to have de novo scoliosis (p = 0.009). Patients who underwent surgery had higher ODI scores (p < 0.001) and a greater incidence of severe radiculopathy (p = 0.006), weakness (p < 0.001), and neurogenic claudication (p = 0.003). Factors associated with operative management on multivariate analysis included weakness (p < 0.001), severe radiculopathy (p = 0.02), and sagittal imbalance (p = 0.03). CONCLUSIONS Neurological symptoms and deficits are common among adults with scoliosis. Development of neurological symptoms and/or deficits is strongly associated with the decision to pursue operative treatment.

Dysphagia following combined anterior-posterior cervical spine surgeries

OBJECT This study was undertaken to evaluate the incidence of and risk factors associated with the development of dysphagia following same-day combined anterior-posterior cervical spine surgeries. METHODS The records of 30 consecutive patients who underwent same-day combined anterior-posterior cervical spine surgery were reviewed. The presence of dysphagia was assessed by a formalized screening protocol using history/clinical presentation and a bedside swallowing test, followed by formal evaluation by speech and language pathologists and/or fiberoptic endoscopic evaluation of swallowing/modified barium swallow when necessary. Age, sex, previous cervical surgeries, diagnoses, duration of procedure, specific vertebral levels and number of levels operated on, degree of sagittal curve correction, use of anterior plate, estimated blood loss, use of recombinant human bone morphogenetic protein-2 (rhBMP-2), and length of hospital stay following procedures were analyzed. RESULTS In the immediate postoperative period, 13 patients (43.3%) developed dysphagia. Outpatient follow-up data were available for 11 patients with dysphagia, and within this subset, all cases of dysphagia resolved subjectively within 12 months following surgery. The mean numbers of anterior levels surgically treated in patients with and without dysphagia were 5.1 and 4.0, respectively (p = 0.004). All patients (100%) with dysphagia had an anterior procedure that extended above C-4, compared with 58.8% of patients without dysphagia (p = 0.010). Patients with dysphagia had significantly greater mean correction of C2-7 lordosis than patients without dysphagia (p = 0.020). The postoperative sagittal occiput-C2 angle and the change in this angle were not significantly associated with the occurrence of dysphagia (p = 0.530 and p = 0.711, respectively). Patients with postoperative dysphagia had significantly longer hospital stays than those who did not develop dysphagia (p = 0.004). No other significant difference between the dysphagia and no-dysphagia groups was identified; differences with respect to history of previous anterior cervical surgery (p = 0.141), use of an anterior plate (p = 0.613), and mean length of anterior cervical operative time (p = 0.541) were not significant. CONCLUSIONS The incidence of dysphagia following combined anterior-posterior cervical surgery in this study was comparable to that of previous reports. The risk factors for dysphagia that were identified in this study were increased number of anterior levels exposed, anterior surgery that extended above C-4, and increased surgical correction of C2-7 lordosis.