A Method of Intraoperative Registration Verification to Prevent Accuracy Errors in Robot-Assisted Stereotactic Electroencephalography Electrode Placement.

BACKGROUND: Robotic-assisted stereotactic electroencephalography (sEEG) electrode placement is increasingly common at specialized epilepsy centers. High accuracy and low complication rates are essential to realizing the benefits of sEEG surgery. The aim of this study was to describe for the first time in the literature a method for a stereotactic registration checkpoint to verify intraoperative accuracy during robotic-assisted sEEG and to report our institutional experience with this technique. METHODS: All cases performed with this technique since the adoption of robotic-assisted sEEG at our institution were retrospectively reviewed. RESULTS: In 4 of 111 consecutive sEEG operations, use of the checkpoint detected an intraoperative registration error, which was addressed before completion of sEEG electrode placement. CONCLUSIONS: The use of a registration checkpoint in robotic-assisted sEEG surgery is a simple technique that can prevent electrode misplacement and improve the safety profile of this procedure.

Effects of 24-hour versus night-float call schedules on the clinical and operative experiences of postgraduate year 2 and 3 neurosurgical residents.

OBJECTIVE: To comply with the removal of the 88-hour week exemption and to support additional operative experience during junior residency, Oregon Health & Science University (OHSU) switched from a night-float call schedule to a modified 24-hour call schedule on July 1, 2019. This study compared the volumes of clinical, procedural, and operative cases experienced by postgraduate year 2 (PGY-2) and PGY-3 residents under these systems. METHODS: The authors retrospectively studied billing and related clinical records, call schedules, and Accreditation Council for Graduate Medical Education case logs for PGY-2 and PGY-3 residents at OHSU, a tertiary academic health center, for the first 4 months of the academic years from 2017 to 2020. The authors analyzed the volumes of new patient consultations, bedside procedures, and operative procedures performed by each PGY-2 and PGY-3 resident during these years, comparing the volumes experienced under each call system. RESULTS: Changing from a PGY-2 resident-focused night-float call system to a 24-hour call system that was more evenly distributed between PGY-2 and PGY-3 residents resulted in decreased volume of new patient consultations, increased volume of operative procedures, and no change in volume of bedside procedures for PGY-2 residents. PGY-3 residents experienced a decrease in operative procedure volume under the 24-hour call system. CONCLUSIONS: Transition from a night-float system to a 24-hour call system altered the distribution of clinical and procedural experiences between PGY-2 and PGY-3 residents. Further research is necessary to understand the impact of these changes on educational outcomes, quality and safety of patient care, and resident satisfaction.

Association of Preoperative Hemoglobin A1c and Body Mass Index with Wound Infection Rate in Spinal Surgery.

BACKGROUND: The deleterious effect of diabetes mellitus on surgical outcomes is well documented for joint replacement surgery. We analyzed the large national US Department of Veterans Affairs (VA) database for patients who had undergone elective spinal surgery. METHODS: We retrospectively searched the VA database and identified 174 520 spine cases. RESULTS: There were 7766 (4.5%) wound infections and 49 271 (28%) had hemoglobin A1c (HbA1c) testing (range: 3.0-17.8) prior to surgery. In the preoperative HbA1c-checked group, there were 2941 (6.0% of 49 271) infections and in the without-preoperative HbA1c group, there were 4825 (3.9% of 125 249) infections. The distribution of infections was significantly different (χ2 = 372.577, P < .0001) and suggests a 2.12% increase in the absolute risk of infection based on the presence of preoperative HbA1c testing, regardless of the result. Logistic regression revealed a preoperative HbA1c test was associated with an odds ratio of 1.435 for infection (confidence interval 1.367-1.505, P < .0001). In a separate model based on HbA1c levels, we found that HbA1c is a significant predictor of infection with an odds ratio of 1.042 (confidence interval 1.017-1.068, P = .0009) for each 1% increase in the test result. This analysis differs from using a strict cutoff value of HbA1c of 6.5%. Similar testing for body mass index and age yielded an odds ratio of 1.027 for each increase of 1 kg/m2 and an odds ratio of 1.009 for each 1-year increase in age respectively. CONCLUSIONS: Hemoglobin A1c testing, HgA1c value, body mass index, and age all contribute to the risk of wound infection after elective spine surgery in a large national VA population. These data can be used to estimate surgical risks and to aid in patient counseling about proposed spine surgery. LEVEL OF EVIDENCE: 4.

Trends in Weight and Body Mass Index after Spinal Surgery for Degenerative Disease.

BACKGROUND: Currently, 37% of adults in the United States are obese, and 34% are overweight. Obesity poses a particularly complex challenge in spinal surgery management, whereby risk of adverse surgical outcomes increases with increased body mass index (BMI). When patients are counseled to reduce weight to levels associated with acceptable surgical risks, patients often respond that their spinal problems prohibit the exercise needed to lose the required weight and counter that surgery will allow for increased activity and thereby facilitate weight loss. A retrospective study of a US Veterans Affairs (USVA) nationwide patient database was undertaken. METHODS: A request was made of the USVA Corporate Data Warehouse for data on all patients undergoing elective spine surgery for degenerative conditions over a 10-year period. RESULTS: The mean preoperative age of 65 667 patients identified was 59 years. The mean preoperative weight was 91.8 kg, and BMI was 29.2. Before surgery, 26 772 patients had a BMI of >30. After surgery, 12 564 (46.9%) lost at least 2.3 kg, 9450 (35.3%) gained at least 2.3 kg, and 4758 (17.8%) were unchanged. After surgery, 4853 (18.1%) lost at least 11.3 kg and 1360 (5.1%) lost at least 22.7 kg. At a mean of 1.9 years after index surgery, mean postoperative weight was 92.5 kg, and BMI was 29.4. Of the 65 667 patients, 23 125 (35.2%) patients lost at least 2.3 kg, 27 571 (42.0%) gained at least 2.3 kg, and 14 971 (23.0%) remained within 2.3 kg of their preoperative weight. CONCLUSION: The study results will aid in counseling patients regarding realistic expectations about weight loss after spinal surgery. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: This evidence will allow for realistic patient counseling regarding the likelihood of weight loss after elective spinal surgery.

Lumbar Fusion With Polyetheretherketone Rods Use for Patients With Degenerative Disease.

INTRODUCTION: Polyetheretherketone (PEEK) rods for lumbar fusion have been available since 2007. However, literature about their utility is sparse and of mixed outcomes. METHODS: A retrospective review of PEEK rod lumbar fusion cases was performed. Data were analyzed from 108 patients of the senior author Donald Ross who underwent PEEK lumbar fusion. RESULTS: There were 97 single and 11 2-level fusions. Rates of tobacco use, diabetes mellitus, low bone density, depression, and immunosuppression were 23.1%, 24.1%, 14.8%, 32.4%, and 6.5%, respectively. In the study population, the mean age was 60.2 years, body mass index was 30.1, and there was a mean 31.3 months for follow-up. There were no wound infections or new neurologic deficits. Of 81 patients with > 11 months of follow-up, 70 (86.4%) had an arthrodesis, 8 (9.9%) had no arthrodesis, and 3 (3.7%) were indeterminate. No patients had revision fusion surgery and 2 patients had adjacent level fusions at 27 and 60 months. One patient had an adjacent segment laminectomy at 18 months and one a foraminotomy at 89 months, resulting in a 3.7% adjacent segment surgery rate. Mean preoperative Short Form-36 (SF-36) physical functioning (PF) score and Oswestry Disability Index (ODI) score were 28.9 and 24.8, respectively. Mean SF-36 PF postoperative score at 1 and 2 years were 59.3 and 65, respectively. Mean ODI postoperative score at 1 year was 14.5. CONCLUSIONS: In a large patient cohort lumbar fusion with PEEK rods can be undertaken with low complication rates, satisfactory clinical improvements, low rates of hardware failure or need for revision surgery. Longer follow-up is needed to confirm findings.

Minimally Invasive Cervical Laminectomy for Cervical Spondylotic Myelopathy.

OBJECTIVE: Cervical spondylotic myelopathy is a common cause of neurological disability, especially in aging populations. There are several approaches to decompress the cervical spinal cord, including anterior cervical discectomy and fusion, corpectomy and fusion, arthroplasty, posterior cervical laminectomy with or without fusion, and laminoplasty. Less well described is minimally invasive cervical laminectomy. The authors report their technique and results for minimally invasive cervical laminectomy. MATERIALS AND METHODS: The authors describe in detail their surgical technique and results of 30 consecutive cases. Preoperative and postoperative modified Japanese Orthopaedic Association (mJOA) myelopathy scores were recorded. RESULTS: In total, 30 cases were included. Mean age was 69 years (range, 57-89 y). Twelve procedures were at C3-4, 4 at C4-5, 5 at C5-6, 4 at C7-T1, 3 at C3-4 and C4-5, 1 at C4-5 and C5-6, and 1 at C5-6 and C6-7. Mean preoperative mJOA score was 12.1 (range, 4-15). Average length of surgery was 142 minutes. Mean follow-up was 27 months (range, 3-64 mo). At 3 months, mean postoperative mJOA score was 14.0 (range, 5-17). Mean mJOA improvement of 1.9 was statistically significant (P<0.001). Seventeen patients had magnetic resonance imaging (MRI) available at 3 months postoperatively (5 patients had no MRI, 3 patients had MRI contraindications, and 5 are pending). No MRI findings led to further surgery. There were no durotomies and no wound infections. A single patient had an unexplained new neurological deficit that resolved over 6 months. CONCLUSIONS: Minimally invasive laminectomy for cervical myelopathy is safe and effective and may be an underutilized procedure.

Diagnosis and Treatment of C4 Radiculopathy.

STUDY DESIGN: Clinical case series. OBJECTIVE: This study sought to clarify symptoms, diagnostic criteria, and treatment of C4 radiculopathy, and the role of diagnostic C4 root block in this entity. SUMMARY OF BACKGROUND DATA: Although well understood cervical dermatomal/myotomal syndromes have been described for symptoms originating from impingement on the C2, C3, C5, C6, C7, and C8 roots, less has been written about the syndrome(s) associated with the C4 root. METHODS: The senior author reviewed surgical records and describes his personal experience with the diagnosis and treatment of C4 radiculopathy. RESULTS: A total of 712 procedures for cervical radiculopathy without myelopathy were reviewed. Among that cohort, 13 procedures involved the C4 root only and five procedures involved two level procedures including the C4 root. Patients described pain as involving the axial cervical region, paraspinal muscles, trapezius muscle, and interscapular region. No patient described pain over the anterior chest wall or radiating distal to the shoulder, one described pain over the medial clavicle. All patients who were offered surgery had a positive response to a diagnostic C4 transforaminal single nerve root block. Thirteen patients underwent posterior foraminotomy (five at two levels) and five patients underwent an anterior discectomy and fusion at C3-4. Mean Oswestry Disability Index score significantly declined; preoperative score 24.3 (range 14-29), postoperative score 9.7 (range 2-18; P = 0.003) at ≥3 months. Mean Short Form-36v2 score significantly increased; preoperative score 34.2 (range 20-40.2), postoperative score 73.7 (range 40.5-88.3, P = 0.001) at ≥3 months. CONCLUSION: C4 root symptoms overlap those of the C3 and C5 roots and are very similar to facet mediated pain. Asymptomatic C4 foraminal stenosis may be a common imaging finding, it can be difficult to diagnose C4 radiculopathy clinically. Diagnostic C4 root block can make an accurate diagnosis and lead to successful surgical outcomes. LEVEL OF EVIDENCE: 4.