Motor vehicle collision characteristics and hospitalization outcomes associated with mild traumatic brain injury and concomitant whiplash injury.

OBJECTIVE: Few large studies have investigated the factors and outcomes related to concomitant injuries occurring alongside mild traumatic brain injury (mTBI) after motor vehicle collisions (MVCs). Thus, the objective of this study was to assess whether MVC characteristics predict which patients with mTBI will have concomitant whiplash injury, and whether concomitant whiplash injury affects care utilization for these patients. METHODS: This retrospective cohort study included 22,213 patients with mTBI after MVC identified from the American College of Surgeons Trauma Quality Programs dataset. A hierarchical logistic regression model was constructed to investigate patient and MVC factors associated with concomitant whiplash injury. Propensity score matching on whiplash status, in conjunction with a multivariable logistic regression model, assessed if concomitant whiplash affected odds of hospitalization. In the subgroup of patients who were hospitalized, associations with hospital length of stay (LOS) and discharge disposition were investigated. RESULTS: The median (IQR) age was 34 (24-51) years, with a median Glasgow Coma Scale score at presentation of 15 (15-15). Patients with concomitant whiplash were older (median 36 years vs 34 years, p = 0.03) and had higher rates of hospitalization (75% vs 64%, p < 0.001). In the hierarchical model for associations with concomitant whiplash injury, patients with blood alcohol content (BAC) greater than the federal driving limit had lower odds of concomitant whiplash (OR 0.63, 95% CI 0.49-0.81) along with those who had airbag deployment (OR 0.80, 95% CI 0.68-0.95), but seatbelt use was associated with greater odds (OR 1.41, 95% CI 1.16-1.71). After matching, concomitant whiplash was independently associated with increased odds of hospitalization (OR 1.67, 95% CI 1.40-1.99) while seatbelt use was associated with decreased odds (OR 0.88, 95% CI 0.81-0.95). Among hospitalized patients, concomitant whiplash was not associated with hospital LOS or discharge disposition. CONCLUSIONS: MVC characteristics such as alcohol consumption and airbag deployment were protective toward development of concomitant whiplash for mTBI patients, while seatbelt use was associated with higher risk. Concomitant whiplash increases the odds of hospitalization for mTBI patients but does not affect hospital LOS or discharge disposition, while seatbelt use is associated with lower rates of hospitalization and a more favorable hospital course. These findings provide context to injury patterns and care provision after a common mechanism of injury.

Comparison of accuracy, revision, and perioperative outcomes in robot-assisted spine surgeries: systematic review and meta-analysis.

OBJECTIVE: Pedicle screw placement guidance is critical in spinal fusions, and spinal surgery robots aim to improve accuracy and reduce complications. Current literature has yet to compare the relative merits of available robotic systems. In this review, the authors aimed to 1) assess the current state of spinal robotics literature; 2) conduct a meta-analysis of robotic performance based on accuracy, speed, and safety; and 3) offer recommendations for robotic system selection. METHODS: Following PRISMA guidelines, the authors conducted a systematic literature review across PubMed, Embase, Cochrane Library, Web of Science, and Scopus as of April 28, 2022, for studies on approved robots for placing lumbar pedicle screws. Three reviewers screened and extracted data relating to the study characteristics, accuracy rate, intraoperative revisions, and reoperations. Secondary performance metrics included operative time, blood loss, and radiation exposure. The authors statistically compared the performance of the robots using a random-effects model to account for variation within and between the studies. Each robot was also compared with performance benchmarks of traditional techniques including freehand, fluoroscopic, and CT-navigated insertion. Finally, we performed a Duval and Tweedie trim-and-fill test to assess for the presence of publication bias. RESULTS: The authors identified 46 studies, describing 4670 patients and 25,054 screws, that evaluated 4 different robotic systems: Mazor X, ROSA, ExcelsiusGPS, and Cirq. The weighted accuracy rates of Gertzbein-Robbins classification grade A or B screws were as follows: ExcelsiusGPS, 98.0%; ROSA, 98.0%; Mazor, 98.2%; and Cirq, 94.2%. No robot was significantly more accurate than the others. However, the accuracy of the ExcelsiusGPS was significantly higher than that of traditional methods, and the accuracies of the Mazor and ROSA were significantly higher than that of fluoroscopy. The intraoperative revision rates were Cirq, 0.55%; ROSA, 0.91%; Mazor, 0.98%; and ExcelsiusGPS, 1.08%. The reoperation rates were Cirq, 0.28%; ExcelsiusGPS, 0.32%; and Mazor, 0.76% (no reoperations were reported for ROSA). Operative times were similar for all robots. Both the ExcelsiusGPS and Mazor were associated with significantly less blood loss than the ROSA. The Cirq had the lowest radiation exposure. Robots tended to be more accurate and generally their use was associated with fewer reoperations and less blood loss than freehand, fluoroscopic, or CT-navigated techniques. CONCLUSIONS: Robotic platforms perform comparably based on key metrics, with high accuracy rates and low intraoperative revision and reoperation rates. The spinal robotics publication rate will continue to accelerate, and choosing a robot will depend on the context of the practice.

Robotic assisted surgery for the treatment of spinal metastases: A case series.

OBJECTIVE: Spinal metastases can significantly affect quality of life in patients with cancer and present complex neurosurgical challenges for surgeons. Surgery with instrumentation is often indicated to alleviate pain, preserve neurological function, and ensure mechanical stability. However, distortions in the bony anatomy due to oncological disease can decrease the accuracy of pedicle screw placement. Robotic-assisted surgery may offer an opportunity to increase screw accuracy and improve navigation of spinal lesions compared to conventional techniques. Therefore, we presented our institutional experience evaluating robotic-assisted surgical fixation for spinal metastases. METHODS: Patients undergoing robotic-assisted surgery at a large tertiary care center between January 2019 - January 2023 for the treatment of spinal metastases were identified. Patient characteristics, including demographics, tumor pathology, surgical complications, and post-operative outcomes were extracted. The Gertzbein Robbins classification system (GRS) was used to assess pedicle screw placement accuracy in patients with post-operative computed tomography. RESULTS: Twenty patients were identified, including 7 females (35 %), with an overall median age of 66 years (range: 39-80 years) and median BMI of 25 kg/m2 (range: 17-34 kg/m2). An average of four spinal levels were instrumented, with metastases located primarily in the thoracic (n=17, 85 %) spine. Common primary tumor types included prostate (n=4), lung (n=2), and plasma cell (n=2) cancers. Most pedicle screws (92 %) were classified as GRS A in patients with postoperative imaging. Post-operative complications were unrelated to the use of the robot, and included pulmonary embolism (n=1), deep vein thrombosis (n=2), and gastric symptoms (n=3). Three patients were readmitted at 30 days, with one reoperation due to tumor recurrence. Four patients were deceased within 6 months of surgery. CONCLUSIONS: Despite the inherent high-risk nature of these surgeries, this study underscores the safety and efficacy of robotic-assisted surgery in the management of spinal metastases. Robots can be helpful in ensuring accuracy of pedicle screw placement in patients with metastatic disease.

Characterizing the presentation, management, and clinical outcomes of patients with intradural spinal chordomas: a systematic review.

OBJECTIVE: Chordomas are locally aggressive neoplasms of the spine or skull base that arise from embryonic remnants of the notochord. Intradural chordomas represent a rare subset of these neoplasms, and few studies have described intradural chordomas in the spine. This review evaluates the presentation, management, and outcomes of intradural spinal chordomas. METHODS: A systematic review of PubMed/MEDLINE, EMBASE, Cochrane Library, Scopus, and Web of Science was performed. Studies describing at least 1 case of intradural chordomas anywhere in the spine were included. Extracted details included presenting symptoms, radiological findings, treatment course, follow-up, and disease progression. RESULTS: Thirty-one studies, with a total of 41 patients, were included in this review. Seventy-six percent (31/41) of patients had primary intradural tumors, whereas 24% (10/41) presented with metastasis. The most common signs and symptoms were pain (n = 27, 66%); motor deficits (n = 20, 49%); sensory deficits (n = 17, 42%); and gait disturbance (n = 10, 24%). The most common treatment for intradural chordoma was resection and postoperative radiotherapy. Sixty-six percent (19/29) of patients reported improvement or complete resolution of symptoms after surgery. The recurrence rate was 37% (10/27), and the complication rate was 25% (6/24). The median progression-free survival was 24 months (range 4-72 months). Four patient deaths were reported. The median follow-up time was 12 months (range 13 days-84 months). CONCLUSIONS: Treatment of intradural spinal chordomas primarily involves resection and radiotherapy. A significant challenge and complication in management is spinal tumor seeding after resection, with 9 studies proposing seeding as a mechanism of tumor metastasis in 11 cases. Factors such as tumor size, Ki-67 positivity, and distant metastasis may correlate with worse outcomes and demonstrate potential as prognostic indicators for intradural spinal chordomas. Further research is needed to improve understanding of this tumor and develop optimal treatment paradigms for these patients.

External Validation of Predictive Models for Failed Medical Management of Spinal Epidural Abscess.

OBJECTIVE: There is limited consensus regarding management of spinal epidural abscesses (SEAs), particularly in patients without neurologic deficits. Several models have been created to predict failure of medical management in patients with SEA. We evaluate the external validity of 5 predictive models in an independent cohort of patients with SEA. METHODS: One hundred seventy-six patients with SEA between 2010 and 2019 at our institution were identified, and variables relevant to each predictive model were collected. Published prediction models were used to assign probability of medical management failure to each patient. Predicted probabilities of medical failure and actual patient outcomes were used to create receiver operating characteristic (ROC) curves, with the area under the receiver operating characteristic curve used to quantify a model's discriminative ability. Calibration curves were plotted using predicted probabilities and actual outcomes. The Spiegelhalter z-test was used to determine adequate model calibration. RESULTS: One model (Kim et al) demonstrated good discriminative ability and adequate model calibration in our cohort (ROC = 0.831, P value = 0.83). Parameters included in the model were age >65, diabetes, methicillin-resistant Staphylococcus aureus infection, and neurologic impairment. Four additional models did not perform well for discrimination or calibration metrics (Patel et al, ROC = 0.580, P ≤ 0.0001; Shah et al, ROC = 0.653, P ≤ 0.0001; Baum et al, ROC = 0.498, P ≤ 0.0001; Page et al, ROC = 0.534, P ≤ 0.0001). CONCLUSIONS: Only 1 published predictive model demonstrated acceptable discrimination and calibration in our cohort, suggesting limited generalizability of the evaluated models. Multi-institutional data may facilitate the development of widely applicable models to predict medical management failure in patients with SEA.

Evaluation of cervical spine clearance scores in children younger than 3 years with blunt trauma.

OBJECTIVE: The PEDSPINE I and PEDSPINE II scores were developed to determine when patients require advanced imaging to rule out cervical spine injury (CSI) in children younger than 3 years of age with blunt trauma. This study aimed to evaluate these scores in an institutional cohort. METHODS: The authors identified patients younger than 3 years with blunt trauma who received cervical spine MRI from their institution's prospective database from 2012 to 2015. Patient demographics, injury characteristics, and imaging were compared between patients with and without CSI using chi-square and Wilcoxon rank-sum tests. RESULTS: Eighty-eight patients were identified, 8 (9%) of whom had CSI on MRI. The PEDSPINE I system had a higher sensitivity (50% vs 25%) and negative predictive value (93% vs 92%), whereas PEDSPINE II had a higher specificity (91% vs 65%) and positive predictive value (22% vs 13%). Patients with CSI missed by the scores had mild, radiologically significant ligamentous injuries detected on MRI. Both models would have recommended advanced imaging for the patient who required halo-vest fixation (risk profile: no CSI, 81.9%; ligamentous, 10.1%; osseous, 8.0%). PEDSPINE I would have prevented 52 (65%) of 80 uninjured patients from receiving advanced imaging, whereas PEDSPINE II would have prevented 73 (91%). Using PEDSPINE I, 10 uninjured patients (13%) could have avoided intubation for imaging. PEDSPINE II would not have spared any patients intubation. CONCLUSIONS: Current cervical spine clearance algorithms are not sensitive or specific enough to determine the need for advanced imaging in children. However, these scores can be used as a reference in conjunction with physicians' clinical impressions to reduce unnecessary imaging.

Fully automatic online geometric calibration for non-circular cone-beam CT orbits using fiducials with unknown placement.

BACKGROUND: Cone-beam CT (CBCT) with non-circular scanning orbits can improve image quality for 3D intraoperative image guidance. However, geometric calibration of such scans can be challenging. Existing methods typically require a prior image, specialized phantoms, presumed repeatable orbits, or long computation time. PURPOSE: We propose a novel fully automatic online geometric calibration algorithm that does not require prior knowledge of fiducial configuration. The algorithm is fast, accurate, and can accommodate arbitrary scanning orbits and fiducial configurations. METHODS: The algorithm uses an automatic initialization process to eliminate human intervention in fiducial localization and an iterative refinement process to ensure robustness and accuracy. We provide a detailed explanation and implementation of the proposed algorithm. Physical experiments on a lab test bench and a clinical robotic C-arm scanner were conducted to evaluate spatial resolution performance and robustness under realistic constraints. RESULTS: Qualitative and quantitative results from the physical experiments demonstrate high accuracy, efficiency, and robustness of the proposed method. The spatial resolution performance matched that of our existing benchmark method, which used a 3D-2D registration-based geometric calibration algorithm. CONCLUSIONS: We have demonstrated an automatic online geometric calibration method that delivers high spatial resolution and robustness performance. This methodology enables arbitrary scan trajectories and should facilitate translation of such acquisition methods in a clinical setting.

Spinal Cord Injury: Emerging Technologies.

The mainstay of treatment for spinal cord injury includes decompressive laminectomy and elevation of mean arterial pressure. However, outcomes often remain poor. Extensive research and ongoing clinical trials seek to design new treatment options for spinal cord injury, including stem cell therapy, scaffolds, brain-spine interfaces, exoskeletons, epidural electrical stimulation, ultrasound, and cerebrospinal fluid drainage. Some of these treatments are targeted at the initial acute window of injury, during which secondary damage occurs; others are designed to help patients living with chronic injuries.

Advancements in Robotic-Assisted Spine Surgery.

Applications and workflows around spinal robotics have evolved since these systems were first introduced in 2004. Initially approved for lumbar pedicle screw placement, the scope of robotics has expanded to instrumentation across different regions. Additionally, precise navigation can aid in tumor resection or spinal lesion ablation. Robot-assisted surgery can improve accuracy while decreasing radiation exposure, length of hospital stay, complication, and revision rates. Disadvantages include increased operative time, dependence on preoperative imaging among others. The future of robotic spine surgery includes automated surgery, telerobotic surgery, and the inclusion of machine learning or artificial intelligence in preoperative planning.

Concomitant Traumatic Brain Injury Delays Surgery in Patients With Traumatic Spinal Cord Injury.

BACKGROUND AND OBJECTIVES: Growing evidence supports prompt surgical decompression for patients with traumatic spinal cord injury (tSCI). Rates of concomitant tSCI and traumatic brain injury (TBI) range from 10% to 30%. Concomitant TBI may delay tSCI diagnosis and surgical intervention. Little is known about real-world management of this common injury constellation that carries significant clinical consequences. This study aimed to quantify the impact of concomitant TBI on surgical timing in a national cohort of patients with tSCI. METHODS: Patient data were obtained from the National Trauma Data Bank (2007-2016). Patients admitted for tSCI and who received surgical intervention were included. Delayed surgical intervention was defined as surgery after 24 hours of admission. Multivariable hierarchical regression models were constructed to measure the risk-adjusted association between concomitant TBI and delayed surgical intervention. Secondary outcome included favorable discharge status. RESULTS: We identified 14 964 patients with surgically managed tSCI across 377 North American trauma centers, of whom 2444 (16.3%) had concomitant TBI and 4610 (30.8%) had central cord syndrome (CCS). The median time to surgery was 20.0 hours for patients without concomitant TBI and 24.8 hours for patients with concomitant TBI. Hierarchical regression modeling revealed that concomitant TBI was independently associated with delayed surgery in patients with tSCI (odds ratio [OR], 1.3; 95% CI, 1.1-1.6). Although CCS was associated with delayed surgery (OR, 1.5; 95% CI, 1.4-1.7), we did not observe a significant interaction between concomitant TBI and CCS. In the subset of patients with concomitant tSCI and TBI, patients with severe TBI were significantly more likely to experience a surgical delay than patients with mild TBI (OR, 1.4; 95% CI, 1.0-1.9). CONCLUSION: Concomitant TBI delays surgical management for patients with tSCI. This effect is largest for patients with tSCI with severe TBI. These findings should serve to increase awareness of concomitant TBI and tSCI and the likelihood that this may delay time-sensitive surgery.

Oncologic and Functional Outcomes After Stereotactic Body Radiation Therapy for High-Grade Malignant Spinal Cord Compression.

Purpose: Although surgical decompression is the gold standard for metastatic epidural spinal cord compression (MESCC) from solid tumors, not all patients are candidates or undergo successful surgical Bilsky downgrading. We report oncologic and functional outcomes for patients treated with stereotactic body radiation therapy (SBRT) to high-grade MESCC. Methods and Materials: Patients with Bilsky grade 2 to 3 MESCC from solid tumor metastases treated with SBRT at a single institution from 2009 to 2020 were retrospectively reviewed. Patients who received upfront surgery before SBRT were included only if postsurgical Bilsky grade remained ≥2. Neurologic examinations, magnetic resonance imaging, pain assessments, and analgesic usage were assessed every 3 to 4 months post-SBRT. Cumulative incidence of local recurrence was calculated with death as a competing risk, and overall survival was estimated by Kaplan-Meier. Results: One hundred forty-three patients were included. The cumulative incidence of local recurrence was 5.1%, 7.5%, and 14.1% at 6, 12, and 24 months, respectively. At first post-SBRT imaging, 16.2% of patients with initial Bilsky grade 2 improved to grade 1, and 53.8% of patients were stable. Five of 13 patients (38.4%) with initial Bilsky grade 3 improved to grade 1 to 2. Pain response at 3 and 6 months post-SBRT was complete in 45.4% and 55.7%, partial in 26.9% and 13.1%, stable in 24.1% and 27.9%, and worse in 3.7% and 3.3% of patients, respectively. At 3 and 6 months after SBRT, 17.8% and 25.0% of patients had improved ambulatory status and 79.7% and 72.4% had stable status. Conclusions: We report the largest series to date of patients with high-grade MESCC treated with SBRT. The excellent local control and functional outcomes suggest SBRT is a reasonable approach in inoperable patients or cases unable to be successfully surgically downgraded.

Initial institutional experience using a robotic arm-enabled 4K 3D exoscope in neurosurgical operations.

The extracorporeal telescope (exoscope) presents a novel digital camera system as a versatile alternative to traditional optical microscopy for microsurgery and minimally invasive neurosurgical operations. Recent innovations in exoscope technology offer 4K-definition multiscreen outputs, pneumatic robot arms, 3-dimensional depth perception, and greater illumination, focus, and magnification powers for enhanced intraoperative visualization. The authors present their initial institutional experience using a robotic arm-enabled 4K 3D exoscope in a variety of cranial and spinal neurosurgical operations, namely Chiari decompression, microvascular decompression for trigeminal neuralgia, anterior cervical discectomy, and lumbar decompressions. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23150.

Tethered spinal cord tension assessed via ultrasound elastography in computational and intraoperative human studies.

BACKGROUND: Tension in the spinal cord is a trademark of tethered cord syndrome. Unfortunately, existing tests cannot quantify tension across the bulk of the cord, making the diagnostic evaluation of stretch ambiguous. A potential non-destructive metric for spinal cord tension is ultrasound-derived shear wave velocity (SWV). The velocity is sensitive to tissue elasticity and boundary conditions including strain. We use the term Ultrasound Tensography to describe the acoustic evaluation of tension with SWV. METHODS: Our solution Tethered cord Assessment with Ultrasound Tensography (TAUT) was utilized in three sub-studies: finite element simulations, a cadaveric benchtop validation, and a neurosurgical case series. The simulation computed SWV for given tensile forces. The cadaveric model with induced tension validated the SWV-tension relationship. Lastly, SWV was measured intraoperatively in patients diagnosed with tethered cords who underwent treatment (spinal column shortening). The surgery alleviates tension by decreasing the vertebral column length. RESULTS: Here we observe a strong linear relationship between tension and squared SWV across the preclinical sub-studies. Higher tension induces faster shear waves in the simulation (R2 = 0.984) and cadaveric (R2 = 0.951) models. The SWV decreases in all neurosurgical procedures (p < 0.001). Moreover, TAUT has a c-statistic of 0.962 (0.92-1.00), detecting all tethered cords. CONCLUSIONS: This study presents a physical, clinical metric of spinal cord tension. Strong agreement among computational, cadaveric, and clinical studies demonstrates the utility of ultrasound-induced SWV for quantitative intraoperative feedback. This technology is positioned to enhance tethered cord diagnosis, treatment, and postoperative monitoring as it differentiates stretched from healthy cords.

Tethered spinal cord syndrome occurs when surrounding tissue attaches to and causes stretching across the spinal cord. People with a tethered cord can experience weakness, pain, and loss of bladder control. Although increased tension in the spinal cord is known to cause these symptoms, evaluating the amount of stretching remains challenging. We investigated the ability of an ultrasound imaging approach to measure spinal cord tension. We studied our method in a computer simulation, a benchtop validation model, and in six people with tethered cords during surgery that they were undergoing to reduce tension. In each phase, the approach could detect differences between stretched spinal cords and spinal cords in a healthy state. Our method could potentially be used in the future to improve the care of people with a tethered cord.

Non-contrast ultrasound image analysis for spatial and temporal distribution of blood flow after spinal cord injury.

Ultrasound technology can provide high-resolution imaging of blood flow following spinal cord injury (SCI). Blood flow imaging may improve critical care management of SCI, yet its duration is limited clinically by the amount of contrast agent injection required for high-resolution, continuous monitoring. In this study, we aim to establish non-contrast ultrasound as a clinically translatable imaging technique for spinal cord blood flow via comparison to contrast-based methods and by measuring the spatial distribution of blood flow after SCI. A rodent model of contusion SCI at the T12 spinal level was carried out using three different impact forces. We compared images of spinal cord blood flow taken using both non-contrast and contrast-enhanced ultrasound. Subsequently, we processed the images as a function of distance from injury, yielding the distribution of blood flow through space after SCI, and found the following. (1) Both non-contrast and contrast-enhanced imaging methods resulted in similar blood flow distributions (Spearman's ρ = 0.55, p < 0.0001). (2) We found an area of decreased flow at the injury epicenter, or umbra (p < 0.0001). Unexpectedly, we found increased flow at the periphery, or penumbra (rostral, p < 0.05; caudal, p < 0.01), following SCI. However, distal flow remained unchanged, in what is presumably unaffected tissue. (3) Finally, tracking blood flow in the injury zones over time revealed interesting dynamic changes. After an initial decrease, blood flow in the penumbra increased during the first 10 min after injury, while blood flow in the umbra and distal tissue remained constant over time. These results demonstrate the viability of non-contrast ultrasound as a clinical monitoring tool. Furthermore, our surprising observations of increased flow in the injury periphery pose interesting new questions about how the spinal cord vasculature reacts to SCI, with potentially increased significance of the penumbra.

Cervical and Lumbar Disk Replacement in Athletes: Is It Safe to Return to Play? A Systematic Review of the Scientific Literature and Lay Press.

BACKGROUND AND OBJECTIVES: Cervical/lumbar total disk replacements (TDRs) are often performed for degenerative conditions but rarely in athletes. Therefore, we sought to conduct a systematic review of athletes undergoing TDRs of both the scientific literature and lay press, with an emphasis on contact sport athletes. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, PubMed/Embase/Cochrane/Scopus/Web of Science databases were queried for all primary literature reporting TDRs in athletes, including both cervical/lumbar disk replacements (CDRs/LDRs). Sports were dichotomized into contact vs limited/noncontact. Because of the public nature of injuries in elite athletes, the lay press was also queried. RESULTS: A total of 488 scientific studies were screened, of which 10 met inclusion criteria. Cervical: seven studies reported CDRs in 53 athletes, of which 7 were professional, 22 semiprofessional, and 24 recreational. Of the seven professional athletes, there was one contact sport athlete (kickboxer). All 7/7 professional and 21/22 semiprofessional athletes successfully returned-to-play at 8-52 weeks without complication. Lumbar: Three studies discussed LDRs in 51 athletes, of which 17 were professional, 6 semiprofessional, and 28 recreational. Of the 17 professional athletes, eight played contact sports (2 boxing, 2 alpine skiing, 2 soccer, judo, rugby). All 17 professional and 6 semiprofessional athletes successfully returned to play at 9-21 weeks. Lay Press: five professional contact sport athletes underwent CDRs, and all returned to play: 3 hockey, 1 mixed-martial arts, and 1 Australian-rules football. CONCLUSION: The scientific literature and lay press revealed 14 professional contact sport athletes who underwent TDR-6 CDRs and 8 LDRs-all with successful return to play. From the little data that exist, it seems that TDR may be safe in elite athletes; however, the small number of patients highlights the major paucity of data on the safety of TDR in elite contact sport athletes.