Data-driven phenotyping of preoperative functional decline patterns in patients undergoing lumbar decompression and lumbar fusion using smartphone accelerometry.

OBJECTIVE: Treatment of degenerative lumbar spine pathologies typically escalates to surgical intervention when symptoms begin to significantly impair patients' functional status. Currently, surgeons rely on subjective patient assessments through patient-reported outcome measures to estimate the decline in patient wellness and quality of life. In this analysis, the authors sought to use smartphone-based accelerometry data to provide an objective, continuous measurement of physical activity that might aid in effective characterization of preoperative functional decline in different lumbar spine surgical indications. METHODS: Up to 1 year of preoperative activity data (steps taken per day) from 14 patients who underwent lumbar decompression and 15 patients who underwent endoscopic lumbar fusion were retrospectively extracted from patient smartphones. A data-driven algorithm was constructed based on 10,585 unique activity data points to identify and characterize the functional decline of patients preceding surgical intervention. Algorithmic estimation of functional decline onset was compared with reported symptom onset in clinical documentation across patients who presented acutely (≤ 5 months of symptoms) or chronically (> 5 months of symptoms). RESULTS: The newly created algorithm identified a statistically significant decrease in physical activity during measured periods of functional decline (p = 0.0020). To account for the distinct clinical presentation phenotypes of patients requiring lumbar decompression (71.4% acute and 28.6% chronic) and those requiring lumbar fusion (6.7% acute and 93.3% chronic), a variable threshold for detecting clinically significant reduced physical activity was implemented. The algorithm characterized functional decline (i.e., acute or chronic presentation) in patients who underwent lumbar decompression with 100% accuracy (sensitivity 100% and specificity 100%), while characterization of patients who underwent lumbar fusion was less effective (accuracy 26.7%, sensitivity 21.4%, and specificity 100%). Adopting a less-permissive detection threshold in patients who underwent lumbar fusion, which rendered the algorithm robust to minor fluctuations above or below the chronically decreased level of preoperative activity in most of those patients, increased functional decline classification accuracy of patients who underwent lumbar fusion to 66.7% (sensitivity 64.3% and specificity 100%). CONCLUSIONS: In this study, the authors found that smartphone-based accelerometer data successfully characterized functional decline in patients with degenerative lumbar spine pathologies. The accuracy and sensitivity of functional decline detection were much lower when using non-surgery-specific detection thresholds, indicating the effectiveness of smartphone-based mobility analysis in characterizing the unique physical activity fingerprints of different lumbar surgical indications. The results of this study highlight the potential of using activity data to detect symptom onset and functional decline in patients, enabling earlier diagnosis and improved prognostication.

Sports-Related Cervical Spine Injuries - Background, Triage, and Prevention.

ABSTRACT: Cervical spinal injuries are a rare, but potentially devastating occurrence in sports. Although many of these injuries occur in unsupervised sports, they are also seen in organized sports - most commonly in football, wrestling, and ice hockey. Additionally, although each sport is associated with its own unique injury patterns, axial loading remains a common theme seen in cervical injuries associated with significant neurologic impairment. Regardless of the mechanism, a cautious and conservative approach should be taken with regards to evaluation, management, and return to play.

Endoscopic transforaminal lumbar interbody fusion without general anesthesia: operative and clinical outcomes in 100 consecutive patients with a minimum 1-year follow-up.

OBJECTIVEOpen spinal fusion surgery is often associated with significant blood loss, postoperative pain, and prolonged recovery times. Seeking to minimize surgical and perioperative morbidity, the authors adopted an endoscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) technique performed without general anesthesia. In this report, they present data on the first 100 patients treated with this procedure.METHODSThe authors conducted a retrospective review of the first 100 patients who underwent awake endoscopic MIS-TLIF at a single institution between 2014 and 2017. Surgery was performed while the patient was sedated but without intubation or the use of general anesthetic or narcotic agents. Long-lasting (liposomal) bupivacaine was used for local analgesia. The discectomy and placement of an expandable interbody graft were performed endoscopically, followed by percutaneous pedicle screw implantation. Inclusion criteria for the procedure consisted of diagnosis of degenerative disc disease with grade I or II spondylolisthesis and evidence of spinal stenosis or nerve impingement with intractable symptomatology.RESULTSOf the first 100 patients, 56 were female and 44 were male. Single-level fusion was performed in 84 patients and two-level fusion in 16 patients. The most commonly fused level was L4-5, representing 77% of all fused levels. The mean (± standard deviation) operative time was 84.5 ± 21.7 minutes for one-level fusions and 128.1 ± 48.6 minutes for two-level procedures. The mean intraoperative blood loss was 65.4 ± 76.6 ml for one-level fusions and 74.7 ± 33.6 ml for two-level fusions. The mean length of hospital stay was 1.4 ± 1.0 days. Four deaths occurred in the 100 patients; all four of those patients died from complications unrelated to surgery. In 82% of the surviving patients, 1-year follow-up Oswestry Disability Index (ODI) data were available. The mean preoperative ODI score was 29.6 ± 15.3 and the mean postoperative ODI score was 17.2 ± 16.9, which represents a significant mean reduction in the ODI score of -12.3 using a two-tailed paired t-test (p = 0.000001). In four cases, the surgical plan was revised to include general endotracheal anesthesia intraoperatively and was successfully completed. Other complications included two cases of cage migration, one case of osteomyelitis, and one case of endplate fracture; three of these complications occurred in the first 50 cases.CONCLUSIONSThis series of the first 100 patients to undergo awake endoscopic MIS-TLIF demonstrates outcomes comparable to those reported in our earlier papers. This procedure can provide a safe and efficacious option for lumbar fusion with less morbidity than open surgery. Further refinements in surgical technique and technologies will allow for improved success.

Novel Combination of Lateral Interbody Fusion and Endoscopic Ipsi-Contra Decompression for Severe Stenosis From Lumbar Spondylolisthesis: A Case Report.

Minimally invasive surgical approaches to the spine that leverage indirect decompression are gaining increasing popularity. While there is excellent literature on the value of indirect decompression, there are limitations to this procedure. Specifically, in patients with severe stenosis and neurogenic claudication, there is a concern among many surgeons regarding the adequacy of indirect decompression alone. In these cases, the lateral approach is often abandoned in favor of an open posterior or posterior minimally invasive approach. Unfortunately, some of the distinct benefits of the direct lateral approach are then lost. Here, we present the case of a 58-year-old male who underwent an L4-L5 lateral interbody fusion with an endoscopic ipsi-contra decompression to achieve both direct and indirect treatment of severe neuroforaminal and central stenosis. From this strategy, this patient had complete pre-operative symptom resolution and was able to return to work immediately after surgery without significant restriction. Combining the benefits of direct and indirect using an ultra-minimally invasive decompressive approach offers a potential solution.

Management of Refractory Post-operative Osteomyelitis and Discitis: A Case Report.

Vertebral osteomyelitis/discitis is a relatively rare disease but is a known potential complication of spinal surgical intervention. In general, the first-line treatment for this condition is targeted antibiotic therapy with surgical intervention only utilized in refractory cases with evidence of extensive damage, structural instability, or abscess formation. However, surgical best practices have not been established for osteomyelitis, including indications for anterior lateral interbody fusion (ALIF), posterior lateral interbody fusion (PLIF), or direct lateral interbody fusion (DLIF). This case provides a discussion of the indications that led to a direct lateral approach in the setting of refractory osteomyelitis/discitis, supporting factors that led to its success, and the efficacy of utilizing intraoperative neuromonitoring in cases of infection.

Endoscopic-assisted fusion for lumbar pars fracture repair in an adolescent patient.

Minimally invasive repair of pars defects can be achieved via means of cannulation followed by tubular decortication. Given these injuries typically occur in pediatric and adolescent patients, minimal disruption to surrounding tissue during the repair is ideal. The use of an endoscopic approach to assist with repair and fusion across the pars defect is a novel consideration in the pediatric demographic, and in this case report we highlight our experience and rationale for this in treating a 14-year-old male athlete with lumbar 5 pars fracture. Radiographic evidence of bony fusion was seen by the third postoperative month. In this case report we demonstrate the invasive nature of this repair can be minimized further than current convention with successful radiographic and clinical outcomes.

Recurrent Osteomyelitis Caused by Mycobacterium abscessus Necessitating Surgical Decompression and Revision Surgery With Interbody Fusion.

Epidural abscesses can be caused by a number of different organisms, including atypical Mycobacterium. This is a rare case report of an atypical Mycobacterium epidural abscess requiring surgical decompression. Here, we present Mycobacterium abscessus causing a nonpurulent epidural collection surgically treated with laminectomy and washout and discuss clinical clues and radiologic characteristics associated with this condition. A 51-year-old male with a past medical history of chronic intravenous (IV) drug use presented with a three-day history of falls and three-month history of progressively worsening bilateral lower extremity radiculopathy, paresthesias, and numbness. MRI demonstrated an enhancing collection at L2-3 ventral and to the left of the spinal canal causing severe compression of the thecal sac, along with heterogenous contrast enhancement of the L2-3 vertebral bodies and intervertebral disc. The patient was taken for an L2-3 laminectomy and left medial facetectomy, where a fibrous, nonpurulent mass was discovered. Cultures ultimately demonstrated Mycobacterium abscessus subspecies massiliense, and the patient was discharged on IV levofloxacin, azithromycin, and linezolid with complete symptomatic relief. Unfortunately, despite surgical washout and antibiotic coverage, the patient presented twice more, the first time with a recurrent epidural collection requiring repeat drainage and the second time with a recurrent epidural collection with discitis and osteomyelitis with pars fractures requiring repeat epidural drainage and interbody fusion. It is important to recognize that atypical Mycobacterium abscessus can cause a nonpurulent epidural collection, especially in high-risk patients such as those with a history of chronic IV drug use. Additionally, our initial intraoperative findings of a fibrous, adherent mass suggest that in cases where this entity is suspected, surgical decompression should be carefully considered. To this end, the radiologic findings associated with this condition, namely, an enhancing ventral epidural mass involving the disc space, should also be recognized. The notable postoperative course consisting of recurrent collections and osteomyelitis with a pars fracture suggests that early fusion should be considered as an option in these patients. This case report presents clinical and radiologic findings associated with an atypical Mycobacterium discitis and osteomyelitis. The clinical course described herein suggests that early fusion in these patients may provide superior results to decompression alone.

A Novel Construct to Treat Destructive Osteomyelitis of the Lumbar Spine in a Patient With Pre-existing Paraplegia.

Treatment for vertebral osteomyelitis varies depending on the extent of pathology and includes both medical and surgical approaches. Pathogen-directed antibiotic therapy is often the first-line treatment, however, refractory cases or those with sepsis, segmental instability, or epidural abscess may be candidates for surgical treatment. Patients with extensive bony destruction often require a corpectomy with the placement of a cage for anterior column reconstruction. In this case report, we describe a patient with a complex past medical history, including paraplegia secondary to a spinal cord infarct, chronic urinary tract infections (UTIs), acute myeloid leukemia (AML), and decubitus ulcers who presented with increasing back pain and imaging demonstrating vertebral osteomyelitis and diskitis with associated epidural abscess extending from L1-L4 vertebral bodies and significant osseous destruction of the L3 and L5 vertebral bodies. A multistage surgical approach was performed involving an initial laminectomy, wound wash-out, and bony debridement followed by an additional wound wash-out and then a posterior approach for corpectomy and graft placement accomplished by tying off the thecal sac. In rare cases where patients present with complete neurologic injury and extensive destructive osteomyelitis, a posterior approach for corpectomy and stabilization may be an option.

Hounsfield Unit as a Predictor of Adjacent-Level Disease in Lumbar Interbody Fusion Surgery.

BACKGROUND: Bone density has been associated with a successful fusion rate in spine surgery. Hounsfield units (HUs) have more recently been evaluated as an indirect representation of bone density. Low preoperative HUs may be an early indicator of global disease and chronic process and, therefore, indicative of the need for future reoperation. OBJECTIVE: To assess preoperative HUs and their association with future adjacent segment disease requiring surgical intervention through retrospective study. METHODS: Patients who underwent lumbar interbody fusion at a single institution between 2007 and 2016 were retrospectively reviewed. Hounsfield unit values were measured from preoperative computed tomography (CT) using sagittal images, encircling cancellous portion of the vertebral body. Patient charts were reviewed for follow-up data and adjacent-level disease development. RESULTS: A total of 793 patients (age: 56.1 ± 13.7 years, 54.4% female) were included in this study. Twenty-two patients required surgical intervention for adjacent segment disease. Patients who underwent lumbar interbody fusion and did not subsequently require surgical intervention for adjacent-level disease were found to have a higher mean preoperative HU than patients who did require reoperation (180.7 ± 70.0 vs 148.4 ± 8.1, P = .032). Preoperative CT HU was a significant independent predictor for the requirement of adjacent-level surgery after spinal arthrodesis (odds ratio = 0.891 [0.883-0.899], P = .029). CONCLUSION: Patients who underwent lumbar interbody fusion that did not require reoperation for adjacent-level degeneration were found to have a higher mean preoperative HU than patients who did require surgical intervention. Lower preoperative CT HU was a significant independent predictor for the requirement of adjacent-level surgery after spinal arthrodesis.

Size matters - From the working channel to the wavelength of light: Optimizing visualization in endoscopic spine surgery.

BACKGROUND: Minimally invasive surgery bases many of its benefits on decreasing tissue disruption. Endoscopic spine surgery has continued to push the boundaries to accomplish successful clinical outcomes through the evolution of the endoscope and working channel. As the indications for endoscopic spine surgery increase, a more profound discussion of cannula size selection for endoscopic spine surgery is required. The intimate relationship between the working channel, the endoscope and how these choices affect workflow and visualization are paramount to maximize outcomes. METHODS: The authors review the nuances of the endoscopic approaches to the various regions of the spine as it relates to the selection of the working channel. The advantages and limitations of various endoscopic working channels were analyzed as to how they address anatomic regional considerations as well as ultimate goals of surgery. RESULTS: In addition to anatomic regional differences and the goals of the surgery other key elements in endoscopic working channel selection included the amount of tissue disruption, regional risk to the neural elements, impact on visualization, optical physics, and the implications for surgical maneuverability/dexterity. CONCLUSION: Understanding the role and use of the endoscope-working channel combination with its effects on visualization is essential for any surgeon aspiring to perform safe and efficient full endoscopic spine surgery.

Developing a Prediction Model for Identification of Distinct Perioperative Clinical Stages in Spine Surgery With Smartphone-Based Mobility Data.

BACKGROUND: Spine surgery outcomes assessment currently relies on patient-reported outcome measures, which satisfy established reliability and validity criteria, but are limited by the inherently subjective and discrete nature of data collection. Physical activity measured from smartphones offers a new data source to assess postoperative functional outcomes in a more objective and continuous manner. OBJECTIVE: To present a methodology to characterize preoperative mobility and gauge the impact of surgical intervention using objective activity data garnered from smartphone-based accelerometers. METHODS: Smartphone mobility data from 14 patients who underwent elective lumbar decompressive surgery were obtained. A time series analysis was conducted on the number of steps per day across a 2-year perioperative period. Five distinct clinical stages were identified using a data-driven approach and were validated with clinical documentation. RESULTS: Preoperative presentation was correctly classified as either a chronic or acute mobility decline in 92% of patients, with a mean onset of acute decline of 11.8 ± 2.9 weeks before surgery. Postoperative recovery duration demonstrated wide variability, ranging from 5.6 to 29.4 weeks (mean: 20.6 ± 4.9 weeks). Seventy-nine percentage of patients ultimately achieved a full recovery, associated with an 80% ± 33% improvement in daily steps compared with each patient's preoperative baseline (P = .002). Two patients subsequently experienced a secondary decline in mobility, which was consistent with clinical history. CONCLUSION: The perioperative clinical course of patients undergoing spine surgery was systematically classified using smartphone-based mobility data. Our findings highlight the potential utility of such data in a novel quantitative and longitudinal surgical outcome measure.

Social Media Presence Across U.S. Neurosurgical Residency Programs and Subspecialties.

OBJECTIVE: U.S. neurosurgery programs are increasingly using social media accounts. We performed a search and analysis of social media accounts across all U.S. neurosurgical training programs with an attempt at understanding the relative utilization by various subspecialties. METHODS: We compiled a list of all Accreditation Council for Graduate Medical Education-accredited U.S. neurosurgery programs and the faculty. Each faculty member was classified on the basis of their subspecialty. Next, the Twitter, Facebook, and Instagram profiles were extensively searched for the number of followers and posts. RESULTS: We analyzed 110 programs with 1829 clinical faculty. Programs with a larger number of faculty (P = 0.035; χ2 = 13.528) and residents (P = 0.003; χ2 = 11.865) were more likely to have a social media account. Likewise, faculty and resident numbers had a positive correlation to Twitter (P = 0.037 for faculty size; P = 0.008 for residents' size) and Instagram followers (P = 0.003 for faculty size; P < 0.001 for residents' size). We additionally found a significant association between subspecialty type and the presence of a Twitter and Instagram account (P = 0.001; P = 0.028) and the number of followers (P = 0.004; P = 0.013), especially the vascular and oncology subspecialties. CONCLUSIONS: Many U.S. neurosurgical programs have social media accounts with larger programs likely to have social media accounts. While there is a larger percentage of spine faculty within individual departments, vascular and oncology subspecialties are more likely to have a Twitter account. We suggest the need for increased engagement among spine faculty across social media platforms.

Technical Considerations of Endoscopic Kambin's Triangle Lumbar Interbody Fusion.

The performance of transforaminal endoscopic lumbar interbody fusion through a Kambin's triangle approach requires significant modifications when compared to a traditional transforaminal discectomy. Indeed, due to the inherently limited field of view, small working corridor, and need to deploy an adequately sized interbody graft, there are several important technical adaptations which can help improve the efficacy of this approach. In this manuscript, the technical aspects of a percutaneous, endoscopic interbody fusion are discussed in detail.

Optimizing Visualization in Endoscopic Spine Surgery.

Given the inherent limitations of spinal endoscopic surgery, proper lighting and visualization are of tremendous importance. These limitations include a small field of view, significant potential for disorientation, and small working cannulas. While modern endoscopic surgery has evolved in spite of these shortcomings, further progress in improving and enhancing visualization must be made to improve the safety and efficacy of endoscopic surgery. However, in order to understand potential avenues for improvement, a strong basis in the physical principles behind modern endoscopic surgery is first required. Having established these principles, novel techniques for enhanced visualization can be considered. Most compelling are technologies that leverage the concepts of light transformation, tissue manipulation, and image processing. These broad categories of enhanced visualization are well established in other surgical subspecialties and include techniques such as optical chromoendoscopy, fluorescence imaging, and 3-dimensional endoscopy. These techniques have clear applications to spinal endoscopy and represent important avenues for future research.

Intraoperative image guidance for endoscopic spine surgery.

Endoscopic spine surgery is a burgeoning component of the minimally invasive spine surgeon's armamentarium. The goals of minimally invasive, and likewise endoscopic, spine surgery include providing equivalent or better patient outcomes compared to conventional open surgery, while minimizing soft tissue disruption, blood loss, postoperative pain, recovery time, and time to return to normal activities. A multitude of indications for the utilization of endoscopy throughout the spinal axis now exist, with applications for both decompression as well as interbody fusion. That being said, spinal endoscopy requires many spine surgeons to learn a completely new skill set and the associated learning curve may be substantial. Fluoroscopy is most common imaging modality used in endoscopic spine surgery for the localization of spinal pathology and endoscopic access. Recently, the use of navigation has been reported to be effective, with preliminary data supporting decreased operative times and radiation exposure, as well as providing for improvements in the associated learning curve. A further development is the recent interest in combining robotic guidance with spinal endoscopy, particularly with respect to endoscopic-assisted lumbar fusion. While there is currently a paucity of literature evaluating these image modalities, they are gaining traction, and future research and innovation will likely focus on these new technologies.

Large prevertebral hematoma and carotid pseudoaneurysm following percutaneous anterior cervical discectomy: illustrative case.

BACKGROUND: The percutaneous, endoscope-assisted anterior cervical discectomy is a relatively new procedure, and because of its novelty, complications are minimal and pertinent literature is scarce. This approach relies on a sufficient anatomical understanding of the vital neurovascular structures in the operating workspace. Although complications are rare, they can be significant. OBSERVATIONS: The patient presented with difficulty breathing following an anterior percutaneous cervical discectomy performed at an outpatient surgical center. Imaging revealed a prevertebral hematoma and multiple carotid pseudoaneurysms. Given the large prevertebral hematoma and concern for imminent airway collapse, the authors proceeded with emergent intubation and surgical evacuation of the clot. LESSONS: The authors propose managing complications in a fashion similar to those for comparable injuries after classic anterior approaches. Definitive management of our patient's carotid injury would require stenting and, therefore, dual antiplatelet agents. Thus, the authors proceeded with the hematoma evacuation first. Additionally, careful dissection was needed to decrease further carotid damage. Thus, the authors made a more rostral incision to maintain the given stability of the carotid insult before the angiographic intervention to follow. It is the authors' hope that the technical pearls from this two-staged open hematoma evacuation and endovascular stenting may guide future presurgical and intraoperative planning and management of complications, should they arise.

Objective Outcomes in Lateral Osteotomy Through Anterior-to-Psoas for Severe Adult Degenerative Spine Deformity Correction.

Multilevel lateral interbody fusion is an acceptable surgical technique in patients with severe degenerative adult spinal deformity (ASD). The current standard-of-care in spine surgery includes the use of patient reported outcome measures (PROMs) to assess post-operative improvement. Objective activity data during the peri-operative period may provide supplementary information for patients recovering from ASD surgery. In this report, we use smartphone-based activity data as an objective outcome measure for a patient who underwent a two-stage operation for ASD corrective surgery: lateral osteotomy and lumbar interbody fusion with posterior column release. An 82-year-old male presented with intractable back pain secondary to severe thoracolumbar scoliotic deformity (Lenke 5BN). Pre-operative images demonstrated the presence of bridging osteophytes over the left lateral aspect of L2-5 disc spaces and over the apex of the lumbar curvature, with significant neuroforaminal stenosis. Surgical correction was completed in two stages: (1) left-sided lateral osteotomy using anterior-to-psoas approach (ATP) in a right lateral decubitus position, and (2) multilevel Ponte osteotomies and instrumented fusion from T10-pelvis. Post-operative radiography showed correction to scoliotic deformity and sagittal misalignment. The patient had developed seroma and wound dehiscence, which was evacuated on post-operative day 11. At 14-month follow-up, the patient reported significant improvement in pain symptoms, corroborated by patient reported outcome measures. To further quantify and assess patient recovery, smartphone-based patient activity data was collected and analyzed to serve as a proxy for the patient's functional improvement. The patient's walking steps-per-day was compared pre- and post-operatively. The patient's pre-operative baseline was 223 steps/day; the patient's activity during immediate post-operative recovery dropped to 179 steps/day; the patient returned to baseline activity levels approximately 3 months after surgery, reaching an average of 216 steps/day. In conclusion, we found that lateral osteotomy through an ATP approach is a powerful tool to restore normal spine alignment and can be successfully performed using anatomic landmarks. Additionally, smartphone-based mobility data can assess pre-operative activity level and allow for remote patient monitoring beyond routine follow-up schedule.

Using Smartphone-Based Accelerometer Data to Objectively Assess Outcomes in Spine Surgery.

BACKGROUND: In order to deliver optimal patient care, spine surgeons must integrate technological changes to arrive at novel measures of functional outcomes. Historically, subjective patient-reported outcome (PRO) surveys have been used to determine the relative benefit of surgical treatments. Using smartphone-based accelerometers, surgeons now have the ability to arrive at objective outcome metrics. OBJECTIVE: To use Apple Health (Apple Inc, Cupertino, California) data to approximate physical activity levels before and after spinal fusion as an objective outcome measurement. METHODS: Personal activity data were acquired retrospectively from the cellphones of consenting patients. These data were used to measure changes in activity level (daily steps, flights climbed, and distance traveled) before and after patients underwent spine surgery at a single institution by a single surgeon. After data collection, we investigated the demographic information and daily physical activity pre- and postoperatively of participating patients. RESULTS: Twenty-three patients were included in the study. On average, patients first exceeded their daily 1-yr average distance walked, flights climbed, and steps taken at 10.3 ± 14, 7.6 ± 21.1, and 8 ± 9.9 wk, respectively. Mean flights climbed, distance traveled, and steps taken decreased significantly from 6 mo prior to surgery to 2 wk postoperatively. Distance traveled and steps taken significantly increased from 6 mo prior to surgery to 7 to 12 mo postoperatively. CONCLUSION: We demonstrated a valuable supplement to traditional PROs by using smartphone-based activity data. This methodology yields a rich data set that has the potential to augment our understanding of patient recovery.

A single institution experience with proximal junctional kyphosis in the context of existing classification schemes - Systematic review.

BACKGROUND: Proximal junctional kyphosis is a kyphotic deformity following spine instrumentation, predominantly seen in scoliosis patients. There have been previous attempts to develop classification schema of PJK. We analyzed the factors contributing to PJK based upon our own clinical experience with the goal of developing a clinical guidance tool which took into account both etiology and mechanism of failure. METHODS: We performed a retrospective analysis of all re-operation thoracolumbar surgeries at a single institution over a 14-year period. Patients with PJK were identified and categorized based upon the etiology, mechanism of failure, and an indication of revision. Next, we conducted a systematic review on articles emphasizing a classification system for PJK. RESULTS: Fourteen PJK patients were identified out of 121 patients who required revision spine surgery. The average age was 64.9 ± 10.2 years, with 10 males (71%) and 4 females (29%). Three primary etiologies were identified: 6/14 (47%) overcorrection, 6/14 (47%) osteopenia, and 2/14 (14%) ligamentous disruption. The mechanism of failure was likewise divided into three categories: 9/14 (64%) compression fracture, 1/14 (7%) hardware failure, and 4/14 (29%) disc degeneration. The relationship between osteopenia and the development of a compression fracture leading to PJK was statistically significant (p = 0.031). CONCLUSION: There are multiple current classification systems for PJK. Our study findings were in line with previously published literature and suggest the need for a future classification system combining both etiology, mechanism of failure, and severity of disease.

Using smartphone-based accelerometers to gauge postoperative outcomes in patients with NPH: Implications for ambulatory monitoring.

BACKGROUND: The surgical treatment of normal pressure hydrocephalus (NPH) with shunting remains controversial due to the difficulty in distinguishing such pathology from other neurological conditions that can present similarly. Thus, patients with suspected NPH should be carefully selected for surgical intervention. Historically, clinical improvement has been measured by the use of functional grades, alleviation of symptoms, and/or patient/family-member reported surveys. Such outcome analysis can be subjective, and there is difficulty in quantifying cognition. Thus, a push for a more quantifiable and objective investigation is warranted, especially for patients with idiopathic NPH (INPH), for which the final diagnosis is confirmed with postoperative clinical improvement. We aimed to use Apple Health (Apple Inc., Cupertino, CA) data to approximate physical activity levels before and after shunt placement for NPH as an objective outcome measurement. The patients were contacted and verbally consented to export Apple Health activity data. The patient's physical activity data were then analyzed. A chart review from the patient's EMR was performed to understand and better correlate recovery. CASE DESCRIPTION: Our first patient had short-term improvements in activity levels when compared to his preoperative activity. The patient's activity level subsequently decreased at 6 months and onward. This decline was simultaneous to new-onset lumbar pain. Our second patient experienced sustained improvements in activity levels for 12 months after his operation. His mobility data were in congruence with his subjectively reported improvement in clinical symptoms. He subsequently experienced a late-decline that began at 48-months. His late deterioration was likely confounded by exogenous factors such as further neurodegenerative diseases coupled with old age. CONCLUSION: The use of objective activity data offers a number of key benefits in the analysis of shunted patients with NPH/INPH. In this distinctive patient population, detailed functional outcome analysis is imperative because the long-term prognosis can be affected by comorbid factors or life expectancy. The benefits from using smartphone-based accelerometers for objective outcome metrics are abundant and such an application can serve as a clinical aid to better optimize surgical and recovery care.