William F. Donaldson

Complications in spinal fusion for adolescent idiopathic scoliosis in the new millennium. A report of the Scoliosis Research Society Morbidity and Mortality Committee.

Study Design. The Morbidity and Mortality database of the Scoliosis Research Society (SRS) was queried as to the incidence and type of complications as reported by its members for the treatment of adolescent idiopathic scoliosis (AIS) with spinal fusion and instrumentation procedures regarding surgical approach (anterior, posterior, or combined anterior-posterior) during a recent 3-year period. Objective. To evaluate the incidence of surgeon-reported complications in a large series of spinal fusions with instrumentation for a single spinal deformity diagnosis and age group regarding surgical approach. Summary of Background Data. The SRS has been collecting morbidity and mortality data from its members since its formation in 1965 with the intent of using these data to assess the complications and adverse outcomes (death and/or spinal cord injury) of surgical treatment for spinal deformity. Surgical approaches to the management of treatment of AIS have a measurable impact on efficacy of correction, levels fused, and operative morbidity. However, there is a lack of consensus on the choice of surgical approach for the treatment of spinal deformity. Methods. Of the 58,197 surgical cases submitted by members of the SRS in the years 2001, 2002, and 2003, 10.9% were identified as having had anterior, posterior, or combined spinal fusion with instrumentation for the diagnosis of AIS, and comprised the study cohort. All reported complications were tabulated and totaled for each of the 3 types of procedures, and statistical analysis was conducted. Results. Complications were reported in 5.7% of the 6334 patients in this series. Of the 1164 patients who underwent anterior fusion and instrumentation, 5.2% had complications, of the 4369 who underwent posterior instrumentation and fusion, 5.1% had complications, and of the 801 who underwent combined instrumentation and fusion, 10.2% had complications. There were 2 patients (0.03%) who died of their complications. There was no statistical difference in overall complication rates between anterior and posterior procedures. However, the difference in complication rates between anterior or posterior procedures compared to combined procedures was highly significant (P < 0.0001). The differences in neurologic complication rates between combined and anterior procedures, as well as combined and posterior procedures were also highly statistically significant (P < 0.0001), but not between anterior and posterior procedures. Conclusions. This study shows that complication rates are similar for anterior versus posterior approaches to AIS deformity correction. Combined anterior and posterior instrumentation and fusion has double the complication rate of either anterior or posterior instrumentation and fusion alone. Combined anterior and posterior instrumentation and fusion also has a significantly higher rate of neurologic complications than anterior or posterior instrumentation and fusion alone.

Rates of infection after spine surgery based on 108,419 procedures: a report from the Scoliosis Research Society Morbidity and Mortality Committee.

Study Design. Retrospective review of a prospectively collected database. Objective. Our objective was to assess the rates of postoperative wound infection associated with spine surgery. Summary of Background Data. Although wound infection after spine surgery remains a common source of morbidity, estimates of its rates of occurrence remain relatively limited. The Scoliosis Research Society prospectively collects morbidity and mortality data from its members, including the occurrence of wound infection. Methods. The Scoliosis Research Society morbidity and mortality database was queried for all reported spine surgery cases from 2004 to 2007. Cases were stratified based on factors including diagnosis, adult (≥21 years) versus pediatric (<21 years), primary versus revision, use of implants, and whether a minimally invasive approach was used. Superficial, deep, and total infection rates were calculated. Results. In total, 108,419 cases were identified, with an overall total infection rate of 2.1% (superficial = 0.8%, deep = 1.3%). Based on primary diagnosis, total postoperative wound infection rate for adults ranged from 1.4% for degenerative disease to 4.2% for kyphosis. Postoperative wound infection rates for pediatric patients ranged from 0.9% for degenerative disease to 5.4% for kyphosis. Rate of infection was further stratified based on subtype of degenerative disease, type of scoliosis, and type of kyphosis for both adult and pediatric patients. Factors associated with increased rate of infection included revision surgery (P < 0.001), performance of spinal fusion (P < 0.001), and use of implants (P < 0.001). Compared with a traditional open approach, use of a minimally invasive approach was associated with a lower rate of infection for lumbar discectomy (0.4% vs. 1.1%; P < 0.001) and for transforaminal lumbar interbody fusion (1.3% vs. 2.9%; P = 0.005). Conclusion. Our data suggest that postsurgical infection, even among skilled spine surgeons, is an inherent potential complication. These data provide general benchmarks of infection rates as a basis for ongoing efforts to improve safety of care.

Postoperative management protocol for incidental dural tears during degenerative lumbar spine surgery: a review of 3,183 consecutive degenerative lumbar cases.

Study Design. Retrospective review. Objectives. To review the experience of a single institution with degenerative lumbar surgery and to identify cases of incidental dural tears (DTs); and to report on the efficacy of our postoperative management protocol for DT, which relies on early mobilization. Summary of Background Data. DTs are a common complication of degenerative lumbar spine surgery. However, the management strategies for this complication vary from one surgeon to another. Methods. A total of 3,183 degenerative lumbar spine cases (decompression and/or fusion) were reviewed. Cases complicated by an incidental DT were identified. Patients who required a return to the operating room for a second procedure were identified and the operative findings were reviewed. Results. The incidence of DT during primary lumbar surgeries was 7.6% (153 of 2,024 cases), which compares to an incidence of 15.9% for revision cases (185 of 1,159 cases). If recognized during the index procedure, all DTs were repaired using a 4-0 silk suture. Six patients (4 primary, 2 revisions) who did not improve despite our postoperative management protocol were taken to the operating room for irrigation and debridement, repair of the defect, and placement of a subfascial drain to closed suction. All 6 patients went on to do well and did not have any further complications. Conclusions. DTs are common during degenerative lumbar spine surgery. Revision surgery is twice as likely as primary surgery to result in this complication. Our postoperative early mobilization protocol appears to be an effective and safe management strategy for treating this complication (98.2% success rate). Very few patients (6 of 338, or 1.8%) needed a reoperation.

Short-term morbidity and mortality associated with correction of thoracolumbar fixed sagittal plane deformity: a report from the Scoliosis Research Society Morbidity and Mortality Committee.

Study Design. Retrospective review. Objective. Our objective was to assess the short-term complication rate in patients undergoing treatment of thoracolumbar fixed sagittal plane deformity (FSPD). Summary of Background Data. The reported morbidity and mortality for the surgical treatment of thoracolumbar FSPD is varied and based on studies with small sample sizes. Further studies are needed to better assess FSPD complication rate, and the factors that influence it. Methods. The Scoliosis Research Society (SRS) Morbidity and Mortality Database was queried to identify cases of thoracolumbar FSPD from 2004 to 2007. Complications were analyzed based on correction technique, surgical approach, surgeon experience (SRS membership status used as a surrogate), patient age, and history of prior surgery. Results. Five hundred and seventy-eight cases of FSPD were identified. Osteotomies were performed in 402 cases (70%), including 215 pedicle subtraction osteotomies (PSO), 135 Smith–Petersen osteotomies (SPO), 19 anterior discectomy with corpectomy procedures (ADC), 18 vertebral column resections (VCR), and 15 unspecified osteotomies. There were 170 complications (29.4%) in 132 patients. There were three deaths (0.5%). The most common complications were durotomy (5.9%), wound infection (3.8%), new neurologic deficit (3.8%), implant failure (1.7%), wound hematoma (1.6%), epidural hematoma (1.4%), and pulmonary embolism (1.0%). Procedures including an osteotomy had a higher complication rate (34.8%) than cases not including an osteotomy (17.0%, P < 0.001), and this remained significant after adjusting for the effects of patient age, surgeon experience, and history of prior surgery (P = 0.003, odds ratio = 2.070, 95% CI = 1.291–3.321). Not significantly associated with complication rate were patient age (P = 0.68), surgeon experience (P = 0.18), and history of prior surgery (P = 0.10). Complication rates were progressively higher from no osteotomy (17.0%), to SPO (28.1%), to PSO (39.1%), to VCR (61.1%). Conclusion. The short-term complication rate for treatment of FSPD is 29.4%. The complication rate was significantly higher in patients undergoing osteotomies, and more aggressive osteotomies were associated with progressively higher complication rates.

The incidence of C5 palsy after multilevel cervical decompression procedures: a review of 750 consecutive cases

Study Design. Retrospective review of 750 consecutive multilevel cervical spine decompression surgeries performed by a single spine surgeon. Objective. To determine the incidence of C5 palsy in a large consecutive series of multilevel cervical spine decompression procedures. Summary of Background Data. Palsy of the C5 nerve is a well-known potential complication of cervical spine surgery with reported rates ranging from 0% to 30%. The etiology remains uncertain but has been attributed to iatrogenic injury during surgery, tethering from shifting of the spinal cord, spinal cord ischemia, and reperfusion injury of the spinal cord. Methods. We included patients undergoing multilevel cervical corpectomy, corpectomy with posterior fusion, posterior laminectomy and fusion, and laminoplasty. Exclusion criteria included lack of follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or surgery not involving the C5 level. Incidence of C5 palsy was determined and compared to determine whether significant differences existed among the various procedures, patient age, sex, revision surgery, preoperative weakness, diabetes, smoking, number of levels decompressed, and history of previous upper extremity surgery. Results. Of the 750 patients, 120 were eliminated on the basis of the exclusion criteria. The 630 patients included in the analysis consisted of 292 females and 338 males. The mean age was 58 years (range, 19–87). The incidence of C5 nerve palsy for the entire group was 42 of 630 (6.7%). The incidence was highest for the laminectomy and fusion group (9.5%), followed by the corpectomy with posterior fusion group (8.4%), the corpectomy group (5.1%), and finally the laminoplasty group (4.8%), although these differences did not reach statistical significance. There was a significantly higher incidence in males (8.6% vs. 4.5%, P = 0.05). Conclusion. Incidence of C5 nerve palsy after cervical spine decompression was 6.7%. This is consistent with previously published studies and represents the largest series of North American patients to date. There is no statistically significant difference in incidence of C5 palsy based on surgical procedure, although there was a trend toward higher rates with laminectomy and fusion.

The effect of airway maneuvers on the unstable C1-C2 segment. A cadaver study.

Study Design. This is a cadaver study in which video fluoroscopy is used to measure motion of the unstable spine at C1-C2 during intubation maneuvers. Objectives. To quantify the amount of motion that occurs at an unstable C1-C2 spinal segment during the use of various intubation techniques using a cadaver model. Summary of Background Date. In previous work by the authors, a methodology and measurements for the unstable C5-C6 segment in a cadaver model were developed. These studies showed that the most motion was created by a chin lift and jaw thrust and that oral techniques created more motion than nasal intubation. The potential motion that occurs during intubation with instability at C1-C2 is yet unstudied. Therefore, a study to determine the effects of intubation on the spine with an unstable C1-C2 segment was designed. Methods. Six human cadavers were used for the study. Measurements before and after transoral osteotomy of the odontoid were performed using video fluoroscopy. Pre-intubation maneuvers and oral and nasal intubation were studied. Results. Oral intubation and nasal intubation caused similar diminution of space available for the cord. Chin lift and jaw thrust caused a larger diminution of space available for the cord than either nasal or oral intubation techniques. Conclusions. Although nasal intubation is the accepted procedure for intubation of the unstable spine, nasal and oral intubation seemed to have the same ability to narrow the space available for the cord in the model in this study. Great care should be taken while performing the chin lift/jaw thrust maneuvers in preparation for intubation, because these pre-intubation techniques caused the most motion and hence narrowed the space available for the cord in the unstable cervical spine.

Cerebrospinal Fluid Leaks Following Cervical Spine Surgery

BACKGROUND A cerebrospinal fluid leak during cervical spine surgery is a feared complication. However, little is known about the prevalence, management, and long-term course of these events. METHODS The medical records of 1994 patients who had elective cervical spine surgery during an eleven-year period (1994 through 2005) were reviewed. Patients with cervical cerebrospinal fluid leaks identified at the time of surgery were followed both clinically and radiographically for an average of 5.4 years postoperatively. The prevalence, etiology, management, and outcome of all of the cervical cerebrospinal fluid leaks were analyzed. RESULTS The overall prevalence of cerebrospinal fluid leaks was 1%. The prevalence of cerebrospinal fluid leaks was higher in patients with a diagnosis of ossification of the posterior longitudinal ligament (12.5%), patients having a revision anterior procedure (1.92%), men (1.56%), and patients undergoing an anterior cervical corpectomy and arthrodesis (1.77%). CONCLUSIONS Many cervical dural tears can be managed by observation alone or by placement of a lumbar cerebrospinal fluid shunt either during the index procedure or in the postoperative period. At an average follow-up of 5.4 years, there were no long-term sequelae of the cervical dural tears in our series.

Complication rates of three common spine procedures and rates of thromboembolism following spine surgery based on 108,419 procedures: A report from the scoliosis research society morbidity and mortality committee

Study Design. Retrospective review of a prospectively collected database. Objective. The Scoliosis Research Society (SRS) collects morbidity and mortality (M and M) data from its members. Our objectives were to assess complication rates for 3 common spine procedures, compare these results with prior literature as a means of validating the database, and to assess rates of pulmonary embolism (PE) and deep venous thrombosis (DVT) in all cases reported to the SRS over 4 years. Summary of Background Data. Few modern series document complication rates of spinal surgery as routinely practiced across academic and community settings. Those available are typically based on relatively low numbers of procedures or confined to single-surgeon experiences. Methods. The SRS M and M database was queried for lumbar microdiscectomy (LD), anterior cervical discectomy and fusion (ACDF), and lumbar stenosis decompression (LSD) cases from 2004 to 2007. Revisions were excluded. The database was also queried for occurrence of clinically evident PE and DVT in all cases from 2004 to 2007. Results. A total of 9692 LDs, 6735 ACDFs, and 10,329 LSDs were identified, with overall complication rates of 3.6%, 2.4%, and 7.0%, respectively. These rates are comparable to previously published smaller series. For assessment of PE and DVT, 108,419 cases were identified and rates were calculated per 1000 cases based on diagnosis, age group, and implant use. Overall rates of PE, death due to PE, and DVT were 1.38, 0.34, and 1.18, respectively. Among 82,082 adults, the rate of PE ranged from 0.47 for LD to 12.4 for metastatic tumor. Similar variations were noted for DVT and deaths due to PE. Conclusion. Overall major complication rates for LD, ACDF, and LSD based on the SRS M and M database are comparable to those in previously reported smaller series, supporting the validity of this database for study of other less common spinal disorders. In addition, our data provide general benchmarks of clinically evident PE and DVT rates as a basis for ongoing efforts to improve care.

Incidence of subaxial subluxation in patients with generalized rheumatoid arthritis who have had previous occipital cervical fusions

A retrospective study of 79 patients with rheumatoid arthritis was undertaken to determine the incidence of subaxial subluxation after upper cervical fusions. Fifty-five patients had isolated axial subluxation and underwent atlantoaxial fusion. Twenty-four underwent occipitocervical fusion for atlantoaxial subluxation and superior migration of the odontoid. The two groups were comparable in age, duration of disease, and time to follow-up (atlantoaxial fusion, 65.4 months; occipitocervical fusion, 72.6 months). Fusion rates were comparable: 80% atlantoaxial fusion and 90.1% occipitocervical fusion. Of the occipitocervical fusion patients, 36% developed subaxial subluxation requiring surgery at an average of 2.6 years after fusion. Of the atlantoaxial fusion patients, 5.5% developed subaxial subluxation requiring surgery after an average of 9 years after fusion. No patient with atlantoaxial fusion developed superior migration of the odontoid. Subaxial subluxation requiring surgery developed early in patients after occipitocervical fusion. This was not true of atlantoaxial fusion. Early atlantoaxial fusion seemed to prevent the development of superior migration of the odontoid. When occipitocervical fusion is necessary and early subaxial subluxation is present, longer fusions or occipitocervicothoracic fusion should be strongly considered.

Cervical spine surgery in rheumatoid arthritis : improvement of neurologic deficit after cervical spine fusion

Ninety of 110 consecutive patients with rheumatoid deformities of the cervical spine surgically treated had associated neurologic deficits. Fifty-five patients had atlantoaxial subluxation. In this group, there were 16 Ranawat Class I patients (normal), 21 Class II (weakness, hyperreflexia, dysesthesia), 13 Class IIIA (paresis and long-tract findings but can ambulate), and five Class IIIB (quadriparesis and inability to ambulate). After C1-C2 stabilization, 94.8% improved at least one class. Twenty-two patients had AAS-SMO (atlanto-axial subluxation and superior migration of the odontoid) only one before surgery was Class I, five Class II, eight Class IIIA, and eight Class IIIB. Seventy-six percent improved at least one class after surgery. Nineteen had isolated subaxial subluxation (SAS). Three were Class I, two Class II, nine Class IIIA, and five were Class IIIB. After surgery, 94% improved at least one class, and all were ambulating. Fourteen had combined AAS-SMO-SAS deformities. There were no Class I patients, only four Class II, four Class IIIA, and six Class IIIB. After surgery, 71% improved. The four deaths that occurred in the immediate postoperative period were Class IIIB. Fifteen patients had worsening or recurrence of their symptoms. Thirteen of these were related to the later development of subaxial subluxation. Neurologic symptoms and recovery were related to severity of the deformity. Those with SMO had greater neurologic deficits and worse results. In general, neurologic recovery is encouraging even in the IIIB patient. Earlier surgery should be done, however, particularly before SMO develops, if possible.(ABSTRACT TRUNCATED AT 250 WORDS)