TNFR1-mediated senescence and lack of TNFR2-signaling limit human intervertebral disc cell repair in back pain conditions.

Poor intervertebral disc (IVD) healing causes IVD degeneration (IVDD) and progression to herniation and back pain. This study identified distinct roles of TNFα-receptors (TNFRs) in contributing to poor healing in painful IVDD. We first isolated IVDD tissue of back pain subjects and determined the complex pro-inflammatory mixture contained many chemokines for recruiting inflammatory cells. Single-cell RNA-sequencing of human IVDD tissues revealed these pro-inflammatory cytokines were dominantly expressed by a small macrophage-population. Human annulus fibrosus (hAF) cells treated with IVDD-conditioned media (CM) underwent senescence with greatly reduced metabolic rates and limited inflammatory responses. TNFR1 inhibition partially restored hAF cell metabolism sufficiently to enable a robust chemokine and cytokine response to CM. We showed that the pro-reparative TNFR2 was very limited on hIVD cell membranes so that TNFR2 inhibition with blocking antibodies or activation using Atsttrin had no effect on hAF cells with CM challenge. However, TNFR2 was expressed in high levels on macrophages identified in scRNA-seq analyses, suggesting their role in repair responses. Results therefore point to therapeutic strategies for painful IVDD involving immunomodulation of TNFR1 signaling in IVD cells to enhance metabolism and enable a more robust inflammatory response including recruitment or delivery of TNFR2 expressing immune cells to enhance IVD repair.

The Fragility of Statistical Findings in Cervical Disc Arthroplasty: a Systematic Review of Randomized Controlled Trials.

PURPOSE: This study employs both the fragility index (FI) and fragility quotient (FQ) to assess the level of robustness in the cervical disc arthroplasty (CDA) literature. We hypothesize that dichotomous outcomes involving CDA would exhibit statistical vulnerability. METHODS: A PubMed search was conducted to evaluate dichotomous data for randomized controlled trials (RCTs) in CDA literature from 2000 to 2023. The FI of each outcome was calculated through the reversal of a single outcome event until significance was reversed. The FQ was calculated by dividing each fragility index by the study sample size. The interquartile range (IQR) was also calculated for the FI and FQ. RESULTS: Of the 1561 articles screened, 111 met the search criteria, with 35 RCTs evaluating CDA included for analysis. Six hundred and ninety-three outcome events with 130 significant (P < 0.05) outcomes and 563 nonsignificant (P ≥ 0.05) outcomes were identified. The overall FI and FQ for all 693 outcomes were 5 (IQR 3-7) and 0.019 (IQR 0.011-0.043). Fragility analysis of statistically significant outcomes and nonsignificant outcomes both revealed an FI of 5. All of the studies reported loss to follow-up (LTF) data where 65.7% (23) did not report or reported an LTF greater or equal to 5. CONCLUSIONS: The literature regarding CDA RCTs lacks statistical robustness and may misrepresent the conclusions with the sole use of the P value. By implementing the FI and FQ along with the P value, we believe the interpretation and contextualization of the clinical data surrounding CDA will be better understood.

Combining adhesive and nonadhesive injectable hydrogels for intervertebral disc repair in an ovine discectomy model.

Background: Intervertebral disc (IVD) disorders (e.g., herniation) directly contribute to back pain, which is a leading cause of global disability. Next-generation treatments for IVD herniation need advanced preclinical testing to evaluate their ability to repair large defects, prevent reherniation, and limit progressive degeneration. This study tested whether experimental, injectable, and nonbioactive biomaterials could slow IVD degeneration in an ovine discectomy model. Methods: Ten skeletally mature sheep (4-5.5 years) experienced partial discectomy injury with cruciate-style annulus fibrosus (AF) defects and 0.1 g nucleus pulposus (NP) removal in the L1-L2, L2-L3, and L3-L4 lumbar IVDs. L4-L5 IVDs were Intact controls. IVD injury levels received: (1) no treatment (Injury), (2) poly (ethylene glycol) diacrylate (PEGDA), (3) genipin-crosslinked fibrin (FibGen), (4) carboxymethylcellulose-methylcellulose (C-MC), or (5) C-MC and FibGen (FibGen + C-MC). Animals healed for 12 weeks, then IVDs were assessed using computed tomography (CT), magnetic resonance (MR) imaging, and histopathology. Results: All repaired IVDs retained ~90% of their preoperative disc height and showed minor degenerative changes by Pfirrmann grading. All repairs had similar disc height loss and Pfirrmann grade as Injury IVDs. Adhesive AF sealants (i.e., PEGDA and FibGen) did not herniate, although repair caused local endplate (EP) changes and inflammation. NP repair biomaterials (i.e., C-MC) and combination repair (i.e., FibGen + C-MC) exhibited lower levels of degeneration, less EP damage, and less severe inflammation; however, C-MC showed signs of herniation via biomaterial expulsion. Conclusions: All repair IVDs were noninferior to Injury IVDs by IVD height loss and Pfirrmann grade. C-MC and FibGen + C-MC IVDs had the best outcomes, and may be appropriate for enhancement with bioactive factors (e.g., cells, growth factors, and miRNAs). Such bioactive factors appear to be necessary to prevent injury-induced IVD degeneration. Application of AF sealants alone (i.e., PEGDA and FibGen) resulted in EP damage and inflammation, particularly for PEGDA IVDs, suggesting further material refinements are needed.

Lumbar endplate microfracture injury induces Modic-like changes, intervertebral disc degeneration and spinal cord sensitization - an in vivo rat model.

BACKGROUND CONTEXT: Endplate (EP) injury plays critical roles in painful IVD degeneration since Modic changes (MCs) are highly associated with pain. Models of EP microfracture that progress to painful conditions are needed to better understand pathophysiological mechanisms and screen therapeutics. PURPOSE: Establish in vivo rat lumbar EP microfracture model and assess crosstalk between IVD, vertebra and spinal cord. STUDY DESIGN/SETTING: In vivo rat EP microfracture injury model with characterization of IVD degeneration, vertebral remodeling, spinal cord substance P (SubP), and pain-related behaviors. METHODS: EP-injury was induced in 5 month-old male Sprague-Dawley rats L4-5 and L5-6 IVDs by puncturing through the cephalad vertebral body and EP into the NP of the IVDs followed by intradiscal injections of TNFα (n=7) or PBS (n=6), compared with Sham (surgery without EP-injury, n=6). The EP-injury model was assessed for IVD height, histological degeneration, pain-like behaviors (hindpaw von Frey and forepaw grip test), lumbar spine MRI and µCT, and spinal cord SubP. RESULTS: Surgically-induced EP microfracture with PBS and TNFα injection induced IVD degeneration with decreased IVD height and MRI T2 signal, vertebral remodeling, and secondary damage to cartilage EP adjacent to the injury. Both EP injury groups showed MC-like changes around defects with hypointensity on T1-weighted and hyperintensity on T2-weighted MRI, suggestive of MC type 1. EP injuries caused significantly decreased paw withdrawal threshold, reduced axial grip, and increased spinal cord SubP, suggesting axial spinal discomfort and mechanical hypersensitivity and with spinal cord sensitization. CONCLUSIONS: Surgically-induced EP microfracture can cause crosstalk between IVD, vertebra, and spinal cord with chronic pain-like conditions. CLINICAL SIGNIFICANCE: This rat EP microfracture model was validated to induce broad spinal degenerative changes that may be useful to improve understanding of MC-like changes and for therapeutic screening.

Lumbar endplate microfracture injury induces Modic-like changes, intervertebral disc degeneration and spinal cord sensitization - An In Vivo Rat Model.

BACKGROUND CONTEXT : Endplate (EP) injury plays critical roles in painful IVD degeneration since Modic changes (MCs) are highly associated with pain. Models of EP microfracture that progress to painful conditions are needed to better understand pathophysiological mechanisms and screen therapeutics. PURPOSE : Establish in vivo rat lumbar EP microfracture model with painful phenotype. STUDY DESIGN/SETTING : In vivo rat study to characterize EP-injury model with characterization of IVD degeneration, vertebral bone marrow remodeling, spinal cord sensitization, and pain-related behaviors. METHODS : EP-driven degeneration was induced in 5-month-old male Sprague-Dawley rats L4-5 and L5-6 IVDs through the proximal vertebral body injury with intradiscal injections of TNFα (n=7) or PBS (n=6), compared to Sham (surgery without EP-injury, n=6). The EP-driven model was assessed for IVD height, histological degeneration, pain-like behaviors (hindpaw von Frey and forepaw grip test), lumbar spine MRI and µCT analyses, and spinal cord substance P (SubP). RESULTS : EP injuries induced IVD degeneration with decreased IVD height and MRI T2 values. EP injury with PBS and TNFα both showed MC type1-like changes on T1 and T2-weighted MRI, trabecular bone remodeling on µCT, and damage in cartilage EP adjacent to the injury. EP injuries caused significantly decreased paw withdrawal threshold and reduced grip forces, suggesting increased pain sensitivity and axial spinal discomfort. Spinal cord dorsal horn SubP was significantly increased, indicating spinal cord sensitization. CONCLUSIONS : EP microfracture can induce crosstalk between vertebral bone marrow, IVD and spinal cord with chronic pain-like conditions. CLINICAL SIGNIFICANCE : This rat EP microfracture model of IVD degeneration was validated to induce MC-like changes and pain-like behaviors that we hope will be useful to screen therapies and improve treatment for EP-drive pain.

Comparison and optimization of sheep in vivo intervertebral disc injury model.

Background: The current standard of care for intervertebral disc (IVD) herniation, surgical discectomy, does not repair annulus fibrosus (AF) defects, which is partly due to the lack of effective methods to do so and is why new repair strategies are widely investigated and tested preclinically. There is a need to develop a standardized IVD injury model in large animals to enable comparison and interpretation across preclinical study results. The purpose of this study was to compare in vivo IVD injury models in sheep to determine which annulus fibrosus (AF) defect type combined with partial nucleus pulposus (NP) removal would better mimic degenerative human spinal pathologies. Methods: Six skeletally mature sheep were randomly assigned to one of the two observation periods (1 and 3 months) and underwent creation of 3 different AF defect types (slit, cruciate, and box-cut AF defects) in conjunction with 0.1 g NP removal in three lumbar levels using a lateral retroperitoneal surgical approach. The spine was monitored by clinical CT scans pre- and postoperatively, at 2 weeks and euthanasia, and by magnetic resonance imaging (MRI) and histology after euthanasia to determine the severity of degeneration (disc height loss, Pfirrmann grading, semiquantitative histopathology grading). Results: All AF defects led to significant degenerative changes detectable on CT and MR images, produced bulging of disc tissue without disc herniation and led to degenerative and inflammatory histopathological changes. However, AF defects were not equal in terms of disc height loss at 3 months postoperatively; the cruciate and box-cut AF defects showed significantly decreased disc height compared to their preoperative height, with the box-cut defect creating the greatest disc height loss, while the slit AF defect showed restoration of normal preoperative disc height. Conclusions: The tested IVD injury models do not all generate comparable disc degeneration but can be considered suitable IVD injury models to investigate new treatments. Results of the current study clearly indicate that slit AF defect should be avoided if disc height is used as one of the main outcomes; additional confirmatory studies may be warranted to generalize this finding.

Acute Vertebral Fractures in Skiing and Snowboarding: A 20-Year Sex-Specific Analysis of National Injury Data.

Background: The epidemiology of acute vertebral fractures (AVFs) sustained while skiing and snowboarding remains poorly defined in the United States. Hypothesis: It was hypothesized that there would be no significant differences across sex and a greater number of AVFs in younger age groups associated with skiing and snowboarding. Study Design: Descriptive epidemiological study. Methods: The authors utilized the National Electronic Injury Surveillance System to identify patients who were reported in emergency departments in the United States from 2000 to 2019. All patients were noted to have sustained AVFs during skiing or snowboarding. National estimates and demographic analysis were performed. Results: A total of 466 AVFs were identified, or roughly 23.3 AVFs per year. Compared with women, men accounted for the majority of AVFs sustained in both skiing and snowboarding: 67.8% (95% CI, 62.6%-73.0%) during skiing and 82.1% (95% CI, 76.3%-87.8%) during snowboarding. This represented a significantly larger percentage of AVFs while snowboarding compared with skiing (P = .002). Women accounted for 32.2% (95% CI, 27.0%-37.4%) of AVFs while skiing and 17.9% (95% CI, 12.2%-23.7%) while snowboarding, which indicated a significantly larger percentage of AVFs sustained during skiing compared with snowboarding (P = .002). Snowboarders were more likely than skiers to sustain an AVF in the region of the coccyx (21.5% [95% CI, 14.3%-28.7%] vs 11.5% [95% CI, 3.5%-16.9%], respectively; P = .003) and as a result of a fall at ground level (69.2% [95% CI, 62.1%-76.4%] vs 52.8% [95% CI, 43.2%-62.4%], respectively; P = .009). A significant decrease in the number of snowboarding-related AVFs was identified over the 20-year study period: 899 in 2000-2003 versus 283 in 2016-2019 (P < .01). The change in skiing-related AVFs over the study period was not statistically significant (694 vs 462; P = .5). Conclusion: This national study of AVFs sustained while skiing and snowboarding identified critical sex- and age-specific differences in the population at risk, anatomic location of injury, and mechanism of injury. The national data generated from this study over a 20-year period may be utilized to better inform public health injury awareness and prevention initiatives in the rapidly growing sports of skiing and snowboarding.

Postoperative Opioid Use and Prescribing Patterns among Patients Undergoing Cervical Laminectomy with Instrumented Fusion versus Cervical Laminoplasty with Reconstruction.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare patterns in opioid usage and prescriptions between patients who undergo cervical laminectomy with instrumented fusion (LF) vs cervical laminoplasty with reconstruction (LP) within single surgeon and national database cohorts. METHODS: We identified patients with cervical myelopathy undergoing primary LF or LP in both a single-surgeon series cohort (2004-2018) and a nationally representative cohort drawn from the IBM® Marketscan® database (2014-2016). We recorded opioid usage within 6 months of surgery and identified differences in unadjusted opioid use rates between LF and LP patients. Multivariable logistic regression was used to evaluate the association between procedure type and postoperative opioid use. RESULTS: Without adjusting for covariates, LF patients had a higher rate of 6-month opioid use in the single-surgeon cohort (15.7% vs 5.1%, P = .02). After adjusting for covariates, LF patients had higher odds of 6-month postoperative opioid use (OR 2.8 [95% CI 1.0-7.7], P = .04). In the national cohort, without adjusting for covariates, there was no significant difference in 6-month opioid use between LF and LP patients. Even after adjusting for covariates, we found no significant difference in odds. CONCLUSIONS: Findings from a single-surgeon cohort reveal that LF is associated with a higher rate of 6-month opioid use than LP. This is at odds with findings from a national database cohort, which suggested that LP and LF patients have similar rates of opioid usage at 6-months postoperatively. To prevent overuse of narcotics, surgeons must consider the distinct pain requirements associated with different procedures even in treatment of the same condition.

Genipin-crosslinked fibrin seeded with oxidized alginate microbeads as a novel composite biomaterial strategy for intervertebral disc cell therapy.

Discectomy procedures alleviate disability caused by intervertebral disc (IVD) herniation, but do not repair herniation-induced annulus fibrosus (AF) defects. Cell therapy shows promise for IVD repair, yet cell delivery biomaterials capable of sealing AF defects and restoring biomechanical function have poor biological performance. To balance the biomechanical and biological demands of IVD cell delivery biomaterials, we engineered an injectable composite biomaterial using cell-laden, degradable oxidized alginate (OxAlg) microbeads (MBs) to deliver AF cells within high-modulus genipin-crosslinked fibrin (FibGen) hydrogels (FibGen + MB composites). Conceptually, the high-modulus FibGen would immediately stabilize injured IVDs, while OxAlg MBs would protect and release cells required for long-term healing. We first showed that AF cells microencapsulated in OxAlg MBs maintained high viability and, upon release, displayed phenotypic AF cell morphology and gene expression. Next, we created cell-laden FibGen + MB composites and demonstrated that OxAlg MBs functionalized with RGD peptides (MB-RGD) minimized AF cell apoptosis and retained phenotypic gene expression. Further, we showed that cell-laden FibGen + MB composites are biomechanically stable and promote extracellular matrix (ECM) synthesis in long-term in vitro culture. Lastly, we evaluated cell-laden FibGen + MB-RGD composites in a long-term bovine caudal IVD organ culture bioreactor and found that composites had low herniation risk, provided superior biomechanical and biological repair to discectomy controls, and retained anabolic cells within the IVD injury space. This novel injectable composite hydrogel strategy shows promise as an IVD cell delivery sealant with potentially broad applications for its capacity to balance biomechanical and biological performance.

Clinically translatable cytokine delivery platform for eradication of intraperitoneal tumors.

Proinflammatory cytokines have been approved by the Food and Drug Administration for the treatment of metastatic melanoma and renal carcinoma. However, effective cytokine therapy requires high-dose infusions that can result in antidrug antibodies and/or systemic side effects that limit long-term benefits. To overcome these limitations, we developed a clinically translatable cytokine delivery platform composed of polymer-encapsulated human ARPE-19 (RPE) cells that produce natural cytokines. Tumor-adjacent administration of these capsules demonstrated predictable dose modulation with spatial and temporal control and enabled peritoneal cancer immunotherapy without systemic toxicities. Interleukin-2 (IL2)-producing cytokine factory treatment eradicated peritoneal tumors in ovarian and colorectal mouse models. Furthermore, computational pharmacokinetic modeling predicts clinical translatability to humans. Notably, this platform elicited T cell responses in NHPs, consistent with reported biomarkers of treatment efficacy without toxicity. Combined, our findings demonstrate the safety and efficacy of IL2 cytokine factories in preclinical animal models and provide rationale for future clinical testing in humans.

Postoperative C5 Palsy Following Cervical Laminectomy With Instrumented Fusion Versus Cervical Laminoplasty With Reconstruction: Single Surgeon and National Inpatient Cohort Analyses.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The objective of this study was to investigate whether cervical laminectomy with instrumented fusion (LF) and cervical laminoplasty with reconstruction (LP) are associated with different rates C5 palsy (C5P) at 1-month follow-up in a single surgeon and nationally representative cohort. SUMMARY OF BACKGROUND DATA: LF and LP both carry a well-known risk of nerve root injury that most commonly presents as C5P which can reduce patient satisfaction, patient function, and impede patient recovery. The procedure type that is more frequently associated with C5P remains largely unclear. METHODS: We identified patients undergoing primary LF or LP procedures for the treatment of cervical myelopathy in both a single-surgeon series cohort (2004-2018; Mount Sinai Hospital) and a nationally representative cohort drawn from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2006-2017). For the single-surgeon cohort, C5P within 1 month of surgery was recorded. For the NSQIP cohort, peripheral nerve injury (PNI) within 1 month of surgery was recorded and used as a proxy for C5P. Postoperative complications including C5P were compared between cohorts. Multivariable logistic regression was used to evaluate the association between procedure type and postoperative C5P or PNI. RESULTS: Without adjusting for covariates, LF patients had a higher rate of 1-month C5P in the single-surgeon cohort (8% vs. 0%, P=0.01). An adjusted odds ratio could not be obtained due to the absence of C5P in the LP group. In the national cohort, LP patients had a significantly higher rate of 1-month PNI on unadjusted analysis (11% vs. 16%, P<0.001). After adjusting for covariates, we found no significant difference in odds of 1-month PNI between LF and LP (adjusted odds ratio=0.84, P=0.07). CONCLUSIONS: Overall, the single-surgeon series suggest that cervical LF is associated with significantly higher rates of postoperative C5P as compared with LP. These findings are not corroborated by nationally representative data, which showed no difference in PNI rates between LF and LP. A surgeon's training and experience likely contribute to which procedure has a higher propensity for a C5P as a complication. Regardless, both LF and LP patients should be closely monitored for new-onset C5P during follow-up visits. LEVEL OF EVIDENCE: Level III.

Accelerometry Data Delineate Phases of Recovery and Supplement Patient-Reported Outcome Measures Following Lumbar Laminectomy.

BACKGROUND: Patient-reported outcome measures (PROMs) are traditionally used to track recovery of patients after spine surgery. Wearable accelerometers have adjunctive value because of the continuous, granular, and objective data they provide. We conducted a prospective study of lumbar laminectomy patients to determine if time-series data from wearable accelerometers could delineate phases of recovery and compare accelerometry data to PROMs during recovery tracking. METHODS: Patients with lumbar stenosis for whom lumbar laminectomy was indicated were prospectively recruited. Subjects wore accelerometers that recorded their daily step counts from at least 1 week preoperatively to 6 months postoperatively. Subjects completed the Oswestry Disability Index and the 12-Item Short Form Health Survey preoperatively and at 2 weeks, 1 month, 3 months, and 6 months postoperatively. Daily aggregate median steps and individual visit-specific median steps were calculated. The Pruned Linear Exact Time method was used to segment aggregate median steps into distinct phases. Associations between visit-specific median steps and PROMs were identified using Spearman rank correlation. RESULTS: Segmentation analysis revealed 3 distinct postoperative phases: step counts rapidly increased for the first 40 days postoperatively (acute healing), then gained more slowly for the next 90 days (recovery), and finally plateaued at preoperative levels (stabilization). Visit-specific median steps were significantly correlated with PROMs throughout the postoperative period. PROMs significantly exceeded baseline at 6 months postoperatively, while step counts did not (all P < 0.05). CONCLUSIONS: Continuous data from accelerometers allowed for identification of 3 distinct stages of postoperative recovery after lumbar laminectomy. PROMs remain necessary to capture subjective elements of recovery.

Management of Acute Subaxial Trauma and Spinal Cord Injury in Professional Collision Athletes.

Sports-related acute cervical trauma and spinal cord injury (SCI) represent a rare but devastating potential complication of collision sport injuries. Currently, there is debate on appropriate management protocols and return-to-play guidelines in professional collision athletes following cervical trauma. While cervical muscle strains and sprains are among the most common injuries sustained by collision athletes, the life-changing effects of severe neurological sequelae (ie, quadriplegia and paraplegia) from fractures and SCIs require increased attention and care. Appropriate on-field management and subsequent transfer/workup at an experienced trauma/SCI center is necessary for optimal patient care, prevention of injury exacerbation, and improvement in outcomes. This review discusses the epidemiology, pathophysiology, clinical presentation, immediate/long-term management, and current return-to-play recommendations of athletes who suffer cervical trauma and SCI.

Enhanced Recovery Components for Posterior Lumbar Spine Fusion: Harnessing National Data to Compare Protocols.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The aim of this study was to assess the most commonly used components of enhanced recovery after surgery (ERAS) combinations and their relative effectiveness. SUMMARY OF BACKGROUND DATA: Data is lacking on use and effectiveness of various ERAS combinations which are increasingly used in spine surgery. MATERIALS AND METHODS: Posterior lumbar fusion cases were extracted from the Premier Healthcare claims database (2006-2016). Seven commonly included components in spine ERAS protocols were identified: (1) multimodal analgesia, (2) tranexamic acid, (3) antiemetics on the day of surgery, (4) early physical therapy, (5) no urinary catheter, (6) no patient-controlled analgesia, and (7) no wound drains. Outcomes were: length of stay, "any complication," blood transfusion, and hospitalization cost. Mixed-effects models measured associations between the most common ERAS combinations and outcomes, separately for 2006-2012 and 2013-2016. Odds ratios (ORs) and 95% confidence intervals (CIs) are reported. RESULTS: Among 97,419 (74%; 2006-2012) and 34,932 (26%; 2013-2016) cases ERAS component variations decreased over time. The most commonly used combinations included multimodal analgesia, antiemetics, early physical therapy, avoidance of a urinary catheter, patient-controlled analgesia and drains (10% n=9401 and 19% n=6635 in 2006-2012 and 2013-2016, respectively), and did not include tranexamic acid. Multivariable models revealed minor differences between ERAS combinations in terms of length of stay and costs. The most pronounced beneficial effects in 2006-2012 were seen for the second most commonly (compared with less often) used ERAS combination(s) in terms of blood transfusion (OR: 0.65; CI: 0.59-0.71) and "any complication" (OR: 0.73; CI: 0.66-0.80), both P<0.05. In 2013-2016 the third most commonly used ERAS combination showed the strongest effect: blood transfusion OR: 0.63; CI: 0.50-0.78, P<0.05. CONCLUSIONS: ERAS component variations decreased over time; maximum benefits were particularly seen in terms of transfusion and complication risk reduction. These findings may inform future ERAS utilization and clinical trials comparing various ERAS protocols.

Osteoporosis is under recognized and undertreated in adult spinal deformity patients.

BACKGROUND: Adult spinal deformity (ASD) patients may have osteoporosis, predisposing them to an increased risk for surgical complications. Prior studies have demonstrated that treating osteoporosis improves surgical outcomes. In this study we determine the prevalence of osteoporosis in ASD patients undergoing long spinal fusions and the rate at which osteoporosis is treated. METHODS: ASD patients who frequented either of two major academic medical centers from 2010 through 2019 were studied. All study participants were at least 40 years of age and endured a spinal fusion of at least seven vertebral levels. Medical records were explored for a diagnosis of osteoporosis via ICD-10 code and, if present, whether pharmacological treatment was prescribed. T-tests and chi-squared analyses were used to determine statistical significance. RESULTS: Three hundred ninety-nine patients matched the study's inclusion criteria. Among this group, 131 patients (32.8%) had been diagnosed with osteoporosis prior to surgery. With a mean age of 66.4 years, osteoporotic patients were on average three years older than non-osteoporotic (P=0.002) and more likely to be female (74.8% vs. 61.9%; P=0.01). At the time of surgery, 34.4% of osteoporotic patients were receiving pharmacological treatment. Although not statistically significant, women were more likely to receive medical treatment than men (P=0.07). CONCLUSIONS: The prevalence of osteoporosis in ASD patients undergoing a long spinal fusion is substantially higher than that of the general population. Surgeons should have a low threshold for bone density testing in ASD patients. With only about one-third of osteoporotic patients treated, there is a classic "missed opportunity" in this population.

Asymptomatic Spinal Cord Compression: Is Surgery Necessary to Return to Play.

Advising athletes with asymptomatic cervical canal stenosis on their return to active play is a topic of considerable debate, with no definitive guidelines in place. Once cervical canal stenosis is identified, often through imaging following other injuries, it is difficult to predict the risk of future injury upon return to play in both contact and collision sports. Consequently, the decision can be a complicated one for the athlete, family, and physician alike. In this article, we identify radiographical and magnetic resonance imaging (MRI)-based criteria that may distinguish athletes "at-risk" for more severe consequences due to asymptomatic cervical canal stenosis from those who are safe to return to play. Using a Torg-Pavlov ratio <0.7 and MRI metrics, namely a minimal disc-level canal diameter <8 mm, a cord-to-canal area ratio >0.8, or space available for the cord <1.2 mm, can help when making these difficult decisions. Counseling can be a critical asset to patients with cervical stenosis who have had a previous episode of cervical cord neuropraxia, especially when they are involved in high-risk sports such as American football and rugby. We believe that while this remains an area of continued concern and controversy, improved MRI criteria will be a useful springboard for further studies, especially in the elite athlete population.

Evidence-Based Management of Spinal Conditions in the Elite Athlete.

Spinal injuries are common and are a significant burden in the professional athlete population. From single-level disk herniation to career-ending fractures, the consequences of these conditions vary widely. Both contact and noncontact injuries can substantially affect the health and performance of elite athletes competing in a variety of sports. The nature and severity of these injuries have great influence on the prospects for full recovery and successful return to play. Common spinal injuries, management decisions, and return to play prospects are important considerations in the professional athlete population.

The Management of Acute Lumbar Stress Reactions of the Pedicle and Pars in Professional Athletes Playing Collision Sports.

Acute stress reactions in the lumbar spine most commonly occur in athletes at the pars interarticularis followed by the pedicle. These reactions occur as a result of repetitive microtrauma from supraphysiological loads applied to the lumbar spine. Characteristic motions such as trunk extension and twisting are also thought to play a role and may be sport-specific. Other risk factors include increased lumbar lordosis, hamstring and thoracolumbar fascia tightness, and abdominal weakness. On physical examination, pain is typically reproduced with lumbar hyperextension. Currently, magnetic resonance imaging or nuclear imaging remain the most sensitive imaging modalities for identifying acute lesions. In the elite athlete, management of these conditions can be challenging, particularly in those playing collision sports such as American football, hockey, or rugby. Nonoperative treatment is the treatment of choice with rehabilitation programs focused on pain-free positioning and progressive strengthening. Operative treatment is rare, but may be warranted for patients symptomatic for >12 months. Specialized diagnosis protocols as well as treatment and return to play guidelines from 4 physicians treating elite athletes playing collision sports are presented and reviewed.

Osteoporosis increases the likelihood of revision surgery following a long spinal fusion for adult spinal deformity.

BACKGROUND: Adult spinal deformity (ASD) can be a debilitating condition that requires surgical intervention. ASD patients often present with osteoporosis, predisposing them to increased rates of instrumentation failure and postoperative fractures, frequent reasons for revision surgery. We hypothesized that the rate and timing of revision surgery are different in osteoporotic and nonosteoporotic patients undergoing long fusions for ASD. To our knowledge, the timing of revision surgeries, in particular, have not previously been explored. PURPOSE: To determine the rate and timing of revision surgery in osteoporotic and nonosteoporotic patients following a long fusion for ASD. STUDY DESIGN: Retrospective comparative study. PATIENT SAMPLE: ASD patients who underwent a long spinal fusion surgery at two large academic medical centers from 2010 to 2019. OUTCOME MEASURES: Occurrence of revision surgery. METHODS: Inclusion criteria were patient age of least 40 years and spinal fusion spanning at least seven levels for ASD. Patient records were reviewed for a diagnosis of osteoporosis as per ICD codes and revision surgery within 2 years of the index procedure. Revision surgery was defined as an unplanned procedure related to the index surgery for the treatment of a spine-related complication. Chi-squared tests comparing demographic data, revision rates, and multiple revisions were conducted. The incidence and prevalence of revision surgeries as a function of time and osteoporotic status were evaluated for significant differences via the Mann-Whitney U and Mantel-Haenszel log rank tests. Finally, a logistic regression analysis was utilized to determine the predictive value of osteoporosis, age, and gender on the likelihood for complications. RESULTS: Three hundred ninety-nine patients matched the study criteria. In the osteoporotic group, 40.5% of patients underwent a revision surgery compared to 28.0% in the nonosteoporotic group (p=.01). The occurrence of multiple revision surgeries following the index procedure was similar in both groups: 8.4% in osteoporotic patients and 8.6% in nonosteoporotic patients. Age and gender were not statistically correlated with the incidence of revision surgery. CONCLUSIONS: ASD patients with osteoporosis have an increased risk of undergoing revision for a surgery-related complication within 2 years of the index procedure. These complications included failure of hardware, pseudoarthrosis, proximal junction failure, and infection, among other issues that required surgical intervention. As others have also highlighted the importance of poor bone density on construct failure, our data further underscore the importance of preoperative osteoporosis surveillance. Though intuitive, further study is needed to demonstrate that improving patients' bone density can decrease the incidence of related complications and the need or revision surgery.