Pearls and pitfalls of posterior superior iliac spine reference frame placement for spinal navigation: cadaveric series.

BACKGROUND: Navigation and robotics are important tools in the spine surgeon's armamentarium and use of these tools requires placement of a reference frame. The posterior superior iliac spine (PSIS) is a commonly used site for reference frame placement, due to its location away from the surgical corridor and its ability to provide solid fixation. Placement of a reference frame requires not only familiarity with proper technique, but also command of the relevant anatomy. OBSERVATIONS: Cadaveric analysis demonstrates a significant difference in PSIS location in males versus females, and additionally provides average thickness for accurate placement. LESSONS: In this technical note, the authors describe the precise technique for PSIS frame placement in addition to relevant anatomy and offer solutions to commonly encountered problems.

Laser Interstitial Thermal Therapy for First-Line Treatment of Surgically Accessible Recurrent Glioblastoma: Outcomes Compared With a Surgical Cohort.

BACKGROUND: Laser interstitial thermal therapy (LITT) for glioblastoma (GBM) has been reserved for poor surgical candidates and deep "inoperable" lesions. We present the first reported series of LITT for surgically accessible recurrent GBM (rGBM) that would otherwise be treated with surgical resection. OBJECTIVE: To evaluate the use of LITT for unifocal, lobar, first-time rGBM compared with a similar surgical cohort. METHODS: A retrospective institutional database was used to identify patients with unifocal, lobar, first-time rGBM who underwent LITT or resection between 2013 and 2020. Clinical and volumetric lesional characteristics were compared between cohorts. Subgroup analysis of patients with lesions ≤20 cm 3 was also completed. Primary outcomes were overall survival and progression-free survival. RESULTS: Of the 744 patients with rGBM treated from 2013 to 2020, a LITT cohort of 17 patients were compared with 23 similar surgical patients. There were no differences in baseline characteristics, although lesions were larger in the surgical cohort (7.54 vs 4.37 cm 3 , P = .017). Despite differences in lesion size, both cohorts had similar extents of ablation/resection (90.7% vs 95.1%, P = .739). Overall survival (14.1 vs 13.8 months, P = .578) and progression-free survival (3.7 vs 3.3 months, P = 0. 495) were similar. LITT patients had significantly shorter hospital stays (2.2 vs 3.0 days, P = .004). Subgroup analysis of patients with lesions ≤20 cm 3 showed similar outcomes, with LITT allowing for significantly shorter hospital stays. CONCLUSION: We found no difference in survival outcomes or morbidity between LITT and repeat surgery for surgically accessible rGBM while LITT resulted in shorter hospital stays and more efficient postoperative care.

Learning curves in robot-assisted spine surgery: a systematic review and proposal of application to residency curricula.

OBJECTIVE: Spine robots have seen increased utilization over the past half decade with the introduction of multiple new systems. Market research expects this expansion to continue over the next half decade at an annual rate of 20%. However, because of the novelty of these devices, there is limited literature on their learning curves and how they should be integrated into residency curricula. With the present review, the authors aimed to address these two points. METHODS: A systematic review of the published English-language literature on PubMed, Ovid, Scopus, and Web of Science was conducted to identify studies describing the learning curve in spine robotics. Included articles described clinical results in patients using one of the following endpoints: operative time, screw placement time, fluoroscopy usage, and instrumentation accuracy. Systems examined included the Mazor series, the ExcelsiusGPS, and the TiRobot. Learning curves were reported in a qualitative synthesis, given as the mean improvement in the endpoint per case performed or screw placed where possible. All studies were level IV case series with a high risk of reporting bias. RESULTS: Of 1579 unique articles, 97 underwent full-text review and 21 met the inclusion and exclusion criteria; 62 articles were excluded for not presenting primary data for one of the above-described endpoints. Of the 21 articles, 18 noted the presence of a learning curve in spine robots, which ranged from 3 to 30 cases or 15 to 62 screws. Only 12 articles performed regressions of one of the endpoints (most commonly operative time) as a function of screws placed or cases performed. Among these, increasing experience was associated with a 0.24- to 4.6-minute decrease in operative time per case performed. All but one series described the experience of attending surgeons, not residents. CONCLUSIONS: Most studies of learning curves with spine robots have found them to be present, with the most common threshold being 20 to 30 cases performed. Unfortunately, all available evidence is level IV data, limited to case series. Given the ability of residency to allow trainees to safely perform these cases under the supervision of experienced senior surgeons, it is argued that a curriculum should be developed for senior-level residents specializing in spine comprising a minimum of 30 performed cases.

Spine Image Guidance and Robotics: Exposure, Education, Training, and the Learning Curve.

The use of intraoperative robotics and imaging for spine surgery has been shown to be safe, efficacious, and beneficial to patients, offering accurate placement of instrumentation, decreased operative time and blood loss, and improved postoperative outcomes. Despite these proven benefits, it has yet to be uniformly adopted. One of the major barriers for universal adoption of intraoperative robotics is the learning curve for this complex technology, in conjunction with a lack of formalized training. These same obstacles for universal adoption were faced in the introduction of surgical technology in other disciplines, and the use of this technology has become the standard of care in some of those specialties. Part of the success and widespread implementation of prior novel technology was the introduction of formalized training systems, which are currently lacking in advanced spine surgical technology. Therefore, the future success of intraoperative robotics and imaging for spine surgery depends on the creation of a formalized training system. We detail the best techniques for surgical pedagogy, as well as propose a comprehensive curriculum.

Augmented Reality in Spine Surgery: A Narrative Review.

Augmented reality (AR) navigation refers to novel technologies that superimpose images, such as radiographs and navigation pathways, onto a view of the operative field. The development of AR navigation has focused on improving the safety and efficacy of neurosurgical and orthopedic procedures. In this review, the authors focus on 3 types of AR technology used in spine surgery: AR surgical navigation, microscope-mediated heads-up display, and AR head-mounted displays. Microscope AR and head-mounted displays offer the advantage of reducing attention shift and line-of-sight interruptions inherent in traditional navigation systems. With the U.S. Food and Drug Administration's recent clearance of the XVision AR system (Augmedics, Arlington Heights, IL), the adoption and refinement of AR technology by spine surgeons will only accelerate.

Risk Factors Associated With 90-Day Readmissions After Degenerative Lumbar Fusion: An Examination of the Michigan Spine Surgery Improvement Collaborative (MSSIC) Registry.

BACKGROUND: Most studies have evaluated 30-d readmissions after lumbar fusion surgery. Evaluation of the 90-d period, however, allows a more comprehensive assessment of factors associated with readmission. OBJECTIVE: To assess the reasons and risk factors for 90-d readmissions after lumbar fusion surgery. METHODS: The Michigan Spine Surgery Improvement Collaborative (MSSIC) registry is a prospective, multicenter, and spine-specific database of patients surgically treated for degenerative disease. MSSIC data were retrospectively analyzed for causes of readmission, and independent risk factors impacting readmission were found by multivariate logistic regression. RESULTS: Of 10 204 patients who underwent lumbar fusion, 915 (9.0%) were readmitted within 90 d, most commonly for pain (17%), surgical site infection (16%), and radicular symptoms (10%). Risk factors associated with increased likelihood of readmission were other race (odds ratio [OR] 1.81, confidence interval [CI] 1.22-2.69), coronary artery disease (OR 1.57, CI 1.25-1.96), ≥4 fused levels (OR 1.41, CI 1.06-1.88), diabetes (OR 1.34, CI 1.10-1.63), and surgery length (OR 1.09, CI 1.03-1.16). Factors associated with decreased risk were discharge to home (OR 0.63, CI 0.51-0.78), private insurance (OR 0.79, CI 0.65-0.97), ambulation same day of surgery (OR 0.81, CI 0.67-0.97), and spondylolisthesis diagnosis (OR 0.82, CI 0.68-0.97). Of those readmitted, 385 (42.1%) patients underwent another surgery. CONCLUSION: Ninety-day readmission occurred in 9.0% of patients, mainly for pain, wound infection, and radicular symptoms. Increased focus on postoperative pain may decrease readmissions. Among factors impacting the likelihood of 90-d readmission, early postoperative ambulation may be most easily modifiable. Optimization of preexisting medical conditions could also potentially decrease readmission risk.

A cohort study of the morbidity of combined anterior-posterior cervical spinal fusions: incidence and predictors of postoperative dysphagia.

PURPOSE: To identify risk factors that may lead to the development of dysphagia after combined anterior and posterior (360°) cervical fusion surgery. METHODS: A single center, retrospective analysis of patients who had same-day, 360° fusion at Henry Ford Hospital between 2008 and 2012 was performed. Variables analyzed included demographics, medical co-morbidities, levels fused, and degree of dysphagia. RESULTS: The overall dysphagia rate was 37.7 %. Patients with dysphagia had a longer mean length of stay (p < 0.001), longer mean operative time (p < 0.001), greater intraoperative blood loss (p = 0.002), and fusion above the fourth cervical vertebra, C4, (p = 0.007). There were no differences in the rates of dysphagia when comparing patients undergoing primary or revision surgery (p = 0.554). CONCLUSION: Prolonged surgery and fusion above C4 lead to higher rates of dysphagia after 360° fusions. Prior anterior cervical fusion does not increase the risk of dysphagia development.

Preoperative external tissue expansion for complex cranial reconstructions.

OBJECTIVE Reconstruction of large solitary cranial defects after multiple craniotomies is challenging because scalp contraction generally requires more than simple subcutaneous undermining to ensure effective and cosmetically appealing closure. In plastic and reconstructive surgery, soft tissue expansion is considered the gold standard for reconstructing scalp defects; however, these techniques are not well known nor are they routinely practiced among neurosurgeons. The authors here describe a simple external tissue expansion technique that is associated with low morbidity and results in high cosmetic satisfaction among patients. METHODS The authors reviewed the medical records of patients with large cranial defects (> 5 cm) following multiple complicated craniotomies who had undergone reconstructive cranioplasty with preoperative tissue expansion using the DermaClose RC device. In addition to gathering data on patient age, sex, primary pathology, number of craniotomies and/or craniectomies, history of radiation therapy, and duration of external scalp tissue expansion, the authors screened patient charts for cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess formation, dermatitis, and patient satisfaction rates. RESULTS The 6 identified patients (5 female, 1 male) had an age range from 36 to 70 years. All patients had complicating factors such as recalcitrant scalp infections after multiple craniotomies or cranial radiation, which led to secondary scalp tissue scarring and retraction. All patients were deemed to be potential candidates for rotational flaps with or without skin grafts. All patients underwent the same preoperative tissue expansion followed by standard cranial bone reconstruction. None of the patients developed CSF leak, meningitis, intracranial abscess, dermatitis, or permanent cosmetic defects. None of the patients required a reoperation. Mean follow-up was 117 days. CONCLUSIONS Preoperative scalp tissue expansion with the DermaClose RC device allows for simple and reliable completion of complicated cranial reconstruction with low morbidity rates and high cosmetic satisfaction among patients.

Nerve Injuries in Aesthetic Breast Surgery: Systematic Review and Treatment Options.

BACKGROUND: The risk of nerve injuries in aesthetic breast surgery has not been well explored. OBJECTIVES: The authors conducted a systematic review to provide evidence-based information on the incidence and treatment of nerve injuries resulting from aesthetic breast surgery. METHODS: A broad literature search of Medline, Embase, and the Cochrane Database of Systematic Reviews was undertaken to identify studies in which nerve injury occurred after breast augmentation or mastopexy. Specific inclusion and exclusion criteria were established before the search was performed. RESULTS: The initial 4806 citations were narrowed by topic, title, and abstract to 53 articles. After full-text review, 36 studies were included. The risk of any nerve injury after breast augmentation ranged from 13.57% to 15.44%. Specific nerve injury rates were calculated for the intercostal cutaneous nerves, branches to the nipple-areola complex, intercostobrachial nerve, long thoracic nerve, and brachial plexus. Also calculated were the total estimated risks of chronic pain, hyperesthesia, hypoesthesia, and numbness. The meta-analysis showed no associations between the rates of breast nerve injury or sensation change and implant size, incision type, or implant position in patients who underwent breast augmentation. The data were insufficient to determine rates of nerve injury in mastopexy. CONCLUSIONS: The possibility of nerve injury, sensation change, or chronic pain with breast augmentation is real, and estimating the incidences of these conditions is useful to both patients and surgeons. Optimizing patient outcomes requires timely treatment by a multidisciplinary team and may include peripheral nerve surgery. LEVEL OF EVIDENCE: 3.

Abdominoplasty-related nerve injuries: systematic review and treatment options.

BACKGROUND: Abdominoplasty is a common cosmetic procedure; nerve injury is an underexplored risk of the procedure. OBJECTIVE: The authors review existing literature to examine the incidence and treatment of nerve injuries after abdominoplasty procedures and provide a treatment algorithm based on their results. METHODS: A search of the literature on MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews was undertaken. After full-text review, 23 articles met our criteria. Any mentions of nerve injury, including references to a lack of nerve injury, were documented. All data were pooled for analysis. From our combined data, we calculated the risks of postabdominoplasty nerve injury by dividing the total number of nerve injuries by the total number of patients. RESULTS: Pooled data showed that 1.94% of patients sustained specific nerve injury, and 1.02% of patients sustained permanent injury after abdominoplasty. In addition, 7.67% experienced decreased sensation, 1.07% reported chronic pain, and 0.44% reported temporary weakness or paralysis. Nerves directly injured were the lateral femoral cutaneous (1.36% of patients) and iliohypogastric (0.10%) nerves. Nerves injured from surgical positioning were the brachial plexus (0.10%), musculocutaneous (0.10%), radial (0.05%), sciatic (0.19%), and common peroneal (0.05%) nerves. CONCLUSIONS: Although our results showed a low incidence of postabdominoplasty nerve injury, the lasting impact on affected patients' quality of life can be significant. Appropriate and timely treatment by a multidisciplinary team is critical to optimize patient outcomes. Better reporting of nerve injuries in future studies of abdominoplasty will provide more accurate information about the incidence and consequences of these injuries. LEVEL OF EVIDENCE: 4.

Small molecule- and amino acid-induced aggregation of gold nanoparticles.

To understand which organic molecules are capable of binding to gold nanoparticles and/or inducing nanoparticle aggregation, we investigate the interaction of gold nanoparticles with small molecules and amino acids at variable pH. Dynamic Light Scattering (DLS) and ultraviolet-visible (UV-vis) spectra were measured on mixtures of colloidal gold with small molecules to track the progression of the aggregation of gold nanoparticles. We introduce the 522 to 435 nm UV-vis absorbance ratio as a sensitive method for the detection of colloidal gold aggregation, whereby we delineate the ability of thiol, amine, and carboxylic acid functional groups to bind to the surfaces of gold nanoparticles and investigate how combinations of these functional groups affect colloidal stability. We present models for mechanisms of aggregation of colloidal gold, including surface charge reduction and bridging linkers. For all molecules whose addition leads to the aggregation of gold nanoparticles, the aggregation kinetics were accelerated at acidic pH values. Colloidal gold is maintained only in the presence of anionic carboxyl groups, which are neutralized by protonation at lower pH. The overall reduced charge on the stabilizing carboxyl groups accounts for the accelerated aggregation at lower pH values.