Timelines for Return to Different Sports Types After Eight Cervical Spine Fractures in Recreational and Elite Athletes: A Survey of the Association for Collaborative Spine Research.

STUDY DESIGN: Prospective cross-sectional survey. OBJECTIVE: To identify timelines for when athletes may be considered safe to return to varying athletic activities after sustaining cervical spine fractures. BACKGROUND: While acute management and detection of cervical spine fractures have been areas of comprehensive investigation, insight into timelines for when athletes may return to different athletic activities after sustaining such fractures is limited. METHODS: A web-based survey was administered to members of the Association for Collaborative Spine Research that consisted of surgeon demographic information and questions asking when athletes (recreational vs elite) with one of 8 cervical fractures would be allowed to return to play noncontact, contact, and collision sports treated nonoperatively or operatively. The third part queried whether the decision to return to sports was influenced by the type of fixation or the presence of radiculopathy. RESULTS: Thirty-three responses were included for analysis. For all 8 cervical spine fractures treated nonoperatively and operatively, significantly longer times to return to sports for athletes playing contact or collision sports compared with recreational and elite athletes playing noncontact sports, respectively (P< 0.05), were felt to be more appropriate. Comparing collision sports with contact sports for recreational and elite athletes, similar times for return to sports for nearly all fractures treated nonoperatively or operatively were noted. In the setting of associated radiculopathy, the most common responses for safe return to play were "when only motor deficits resolve completely" and "when both motor and sensory deficits resolve completely." CONCLUSIONS: In this survey of spine surgeons from the Association for Collaborative Spine Research, reasonable timeframes for return to play for athletes with 8 different cervical spine fractures treated nonoperatively or operatively varied based on fracture subtype and level of sporting physicality.

Use of Osteobiologics for Fracture Management: The When, What, and How.

Osteobiologics are defined as a group of natural and synthetic materials used to augment bone healing. The selection of the most appropriate osteobiologic from the growing list of available options can be a challenging task. In selecting a material, surgeons should weigh a variety of considerations, including the indication for their use (the when), the most suitable substance (the what), and the correct mode of application (the how). This summary reviews these considerations and seeks to provide the surgeon with a basis for informed clinical evidence-based decision-making in their choice of a successful option.

Na+-sensitive elevation in blood pressure is ENaC independent in diet-induced obesity and insulin resistance.

The majority of patients with obesity, insulin resistance, and metabolic syndrome have hypertension, but the mechanisms of hypertension are poorly understood. In these patients, impaired sodium excretion is critical for the genesis of Na(+)-sensitive hypertension, and prior studies have proposed a role for the epithelial Na(+) channel (ENaC) in this syndrome. We characterized high fat-fed mice as a model in which to study the contribution of ENaC-mediated Na(+) reabsorption in obesity and insulin resistance. High fat-fed mice demonstrated impaired Na(+) excretion and elevated blood pressure, which was significantly higher on a high-Na(+) diet compared with low fat-fed control mice. However, high fat-fed mice had no increase in ENaC activity as measured by Na(+) transport across microperfused cortical collecting ducts, electrolyte excretion, or blood pressure. In addition, we found no difference in endogenous urinary aldosterone excretion between groups on a normal or high-Na(+) diet. High fat-fed mice provide a model of metabolic syndrome, recapitulating obesity, insulin resistance, impaired natriuresis, and a Na(+)-sensitive elevation in blood pressure. Surprisingly, in contrast to previous studies, our data demonstrate that high fat feeding of mice impairs natriuresis and produces elevated blood pressure that is independent of ENaC activity and likely caused by increased Na(+) reabsorption upstream of the aldosterone-sensitive distal nephron.

Comparison of Expandable and Fixed Interbody Cages in a Human Cadaver Corpectomy Model: Fatigue Characteristics.

STUDY DESIGN: In vitro cadaver biomechanics study. OBJECTIVE: The goal of this study is to compare the in situ fatigue life of expandable versus fixed interbody cage designs. SUMMARY OF BACKGROUND DATA: Expandable cages are becoming more popular, in large part, due to their versatility; however, subsidence and catastrophic failure remain a concern. This in vitro analysis investigates the fatigue life of expandable and fixed interbody cages in a single level human cadaver corpectomy model by evaluating modes of subsidence of expandable and fixed cages as well as change in stiffness of the constructs with cyclic loading. METHODS: Nineteen specimens from 10 human thoracolumbar spines (T10-L2, L3-L5) were biomechanically evaluated after a single level corpectomy that was reconstructed with an expandable or fixed cage and anterior dual rod instrumentation. All specimens underwent 98 K cycles to simulate 3 months of postoperative weight bearing. In addition, a third group with hyperlordotic cages was used to simulate catastrophic failure that is observed in clinical practice. RESULTS: Three fixed and 2 expandable cages withstood the cyclic loading despite perfect sagittal and coronal plane fitting of the endcaps. The majority of the constructs settled in after initial subsidence. The catastrophic failures that were observed in clinical practice could not be reproduced with hyperlordotic cages. However, all cages in this group subsided, and 60% resulted in endplate fractures during deployment of the cage. CONCLUSIONS: Despite greater surface contact area, expandable cages have a trend for higher subsidence rates when compared with fixed cages. When there is edge loading as in the hyperlordotic cage scenario, there is a higher risk of subsidence and intraoperative fracture during deployment of expandable cages.

Cervical spine clearance protocols in level 1 trauma centers in the United States.

STUDY DESIGN: Observational, cross-sectional. OBJECTIVE: To evaluate cervical spine clearance protocols in level 1 trauma centers in the United States. SUMMARY OF BACKGROUND DATA: Cervical spine clearance protocols were developed to prevent missed injuries that could result in neurological deficits. The degree of incorporation of evidence-based guidelines into protocols at trauma centers in the United States is unknown. METHODS: Level 1 trauma (n = 191) centers in the United States were contacted. Each available protocol was reviewed for 4 scenarios: clearing the asymptomatic patient, the imaging used in patients not amenable to clinical clearance, the management strategies for patients with persistent neck pain with a negative computed tomographic (CT) scan, and those who are obtunded. RESULTS: The response rate was 87%. Cervical spine clearance protocols existed in 57% of the institutions. National Emergency X-Radiography Utilization Study criteria to clear asymptomatic patients were recommended in 89% of protocols. Sixty percent of protocols used CT scans as the first line of imaging. In patients with persistent neck pain with negative CT scan flexion-extension plain radiographs were the most common (30%) next step for clearance. In patients who are obtunded, a CT scan followed by a magnetic resonance imaging was the most common method (31%) of clearance. Eight percent of the protocols recommended dynamic flexion-extension views in patients who are obtunded, which are contraindicated. CONCLUSION: Written cervical spine clearance protocols exist in 57% of level 1 trauma centers in the United States. These protocols are highly variable and standardization and utilization of these protocols should be encouraged in all trauma centers to prevent missed injuries and neurological catastrophes. LEVEL OF EVIDENCE: 4.

Conversion from tacrolimus/mycophenolic acid to tacrolimus/leflunomide to treat cutaneous warts in a series of four pediatric renal allograft recipients.

BACKGROUND: The challenge of immunosuppression in pediatric renal transplantation is to balance preventing rejection while avoiding infectious complications. A dermatological complication of immunosuppression is viral warts, which cause significant disfigurement and increase the risk of skin malignancy. METHODS: We present three pediatric and adolescent renal allograft recipients with multiple, recalcitrant verrucae vulgares lesions and one patient with molluscum contagiosum who were switched from mycophenolate mofetil to leflunomide. Teriflunomide metabolite levels were carefully maintained between 50,000 and 100,000 ng/mL to balance its immunosuppressive and antiviral properties. No adverse events requiring discontinuation of leflunomide were encountered. RESULTS: Switching from mycophenolate mofetil to leflunomide successfully cleared verrucae vulgares and molluscum lesions in all four renal transplant patients. CONCLUSIONS: The ability to minimize and even resolve warts can improve quality of life by reducing risk of skin malignancies and emotional distress in solid organ transplant patients. Leflunomide is a potential therapeutic option for posttransplantation patients with skin warts because it serves both as an adjunct to the immunosuppressive regimen and an antiviral agent.

Advances in biomaterials and surface technologies.

Tremendous advances in quality, reliability, performance, and versatility of surgical instrumentation and devices have been achieved over the past 50 years using biomaterials. The global orthopaedic implant industry is expected to grow to $41.8 billion by 2016, driven primarily by advancements in implant designs, including materials that provide improved biocompatibility, durability, and expanded clinical applications. Biomaterials have evolved through 3 clinical "generations": (1) "bio-inert materials," (2) materials with intrinsic bioactivity and degradability, and (3) biomaterials that stimulate specific biological host responses. In all cases, surface modifications, including coatings, represent a key strategy for improvements in tissue-contacting properties. Surfaces continue to be a focus for many device improvements and for tissue interfacing, especially for many orthopaedic structural implants comprising metal and metal alloys. Progress in implant materials processing, coating technologies, and coating combinations with therapeutic agents provide new properties and functionalities to improve device-tissue integration and reduce foreign body reactions and infections. Performance criteria for these surface modifications success in clinical practice are daunting, and translation of several technologies from in vitro proof-of-concept to in vivo applications has proven challenging.

Informed consent for ankle fracture surgery: patient comprehension of verbal and videotaped information.

BACKGROUND: The purpose of our study was to evaluate the effectiveness of using a videotape to give patients information about the risks, benefits, alternatives, and treatment of a common orthopaedic procedure before they sign consent forms. METHODS: During a 9-month period, 48 patients with isolated closed ankle fractures requiring surgical intervention were randomized into two groups that received either videotaped or conventional verbal information regarding consent for surgery. The study group watched a videotape containing information about the risks, benefits, and treatment alternatives, while the control group obtained this information verbally. To determine comprehension and retention, all patients completed a multiple-choice questionnaire immediately after receiving the information, and 37 patients (77%) were available to complete a questionnaire at an average of 10 weeks later. RESULTS: The videotape group outperformed the verbal consent group by 40.1% on the initial questionnaire (p = .0002) and by 27.2% on the followup questionnaire (p = 0.0139). Patients with educational levels of less than or equal to the 12th grade performed 67.8% better on the initial questionnaire after watching the video than after receiving the information verbally. (p = .0001). CONCLUSION: Patients who received information about their surgery on a videotape before giving their consent demonstrated a significant increase in comprehension compared to patients who received this information verbally. The benefit was even greater for patients with lower education levels.

Follicular unit extraction: minimally invasive surgery for hair transplantation.

BACKGROUND: Follicular Unit Transplantation (FUT) is performed using large numbers of naturally occuring individual follicular units obtained by single-strip harvesting and stereo-microscopic dissection. Donor wound scarring from strip excision, although an infrequent complication, still concerns enough patients that an alternative solution is warranted. OBJECTIVE: The purpose of this paper is to introduce Follicular Unit Extraction (The FOX Procedure), in which individual follicular units are removed directly from the donor region through very small punch excisions, and to describe a test (The FOX Test) that determines which patients are candidates for this procedure. This paper explores the nuances, limitations, and practical aspects of Follicular Unit Extraction (FUE). METHODS: FUE was performed using 1-mm punches to separate follicular units from the surrounding tissue down to the level of the mid dermis. This was followed by extraction of the follicular units with forceps. The FOX test was developed to determine which patients would be good candidates for the procedure. The test was performed on 200 patients. Representative patients who were FOX-positive and FOX-negative were studied histologically. RESULTS: The FOX Test can determine which patients are suitable candidates for FUE. Approximately 25% of the patients biopsied were ideal candidates for FUE and 35% of the patients biopsied were good candidates for extraction. CONCLUSION: FUE is a minimally invasive approach to hair transplantation that obviates the need for a linear donor incision. This technique can serve as an important alternative to traditional hair transplantation in certain patients.

Hyperexcitability and epilepsy associated with disruption of the mouse neuronal-specific K-Cl cotransporter gene.

Four genes encode electroneutral, Na+-independent, K-Cl cotransporters. KCC2, is exclusively expressed in neurons where it is thought to drive intracellular Cl- to low concentrations and shift the reversal potential for Cl- conductances such as GABA(A) or glycine receptor channels, thus participating in the postnatal development of inhibitory mechanisms in the brain. Indeed, expression of the cotransporter is low at birth and increases postnatally, at a time when the intracellular Cl- concentration in neurons decreases and gamma-aminobutyric acid switches its effect from excitatory to inhibitory. To assert the significance of KCC2 in neuronal function, we disrupted the mouse gene encoding this neuronal-specific K-Cl cotransporter. We demonstrate that animals deficient in KCC2 exhibit frequent generalized seizures and die shortly after birth. We also show upregulation of Fos, the product of the immediate early gene c-fos, and the significant loss of parvalbumin-positive interneurons, both indicative of brain injury. The regions most affected are the hippocampus and temporal and entorhinal cortices. Extracellular field potential measurements in the CA1 hippocampus exhibited hyperexcitability. Application of picrotoxin, a blocker of the GABA(A) receptor, further increased hyperexcitability in homozygous hippocampal sections. Pharmacological treatment of pups showed that diazepam relieved the seizures while phenytoin prevented them between postnatal ages P4-P12. Finally, we demonstrate that adult heterozygote animals show increased susceptibility for epileptic seizure and increased resistance to the anticonvulsant effect of propofol. Taken together, these results indicate that KCC2 plays an important role in controlling CNS excitability during both postnatal development and adult life.