Transplantation of GABAergic Interneurons into the Neonatal Primary Visual Cortex Reduces Absence Seizures in Stargazer Mice.

Epilepsies are debilitating neurological disorders characterized by repeated episodes of pathological seizure activity. Absence epilepsy (AE) is a poorly understood type of seizure with an estimated 30% of affected patients failing to respond to antiepileptic drugs. Thus, novel therapies are needed for the treatment of AE. A promising cell-based therapeutic strategy is centered on transplantation of embryonic neural stem cells from the medial ganglionic eminence (MGE), which give rise to gamma-aminobutyric acidergic (GABAergic) interneurons during embyronic development. Here, we used the Stargazer (Stg) mouse model of AE to map affected loci using c-Fos immunohistochemistry, which revealed intense seizure-induce activity in visual and somatosensory cortices. We report that transplantation of MGE cells into the primary visual cortex (V1) of Stg mice significantly reduces AE episodes and lowers mortality. Electrophysiological analysis in acute cortical slices of visual cortex demonstrated that Stg V1 neurons exhibit more pronounced increases in activity in response to a potassium-mediated excitability challenge than wildtypes (WT). The defective network activity in V1 was significantly altered following WT MGE transplantation, associating it with behavioral rescue of seizures in Stgs. Taken together, these findings present MGE grafting in the V1 as a possible clinical approach in the treatment of AE.

Antibiotic cement nails manufactured with threaded rods or cannulated intramedullary nails are better than those made with guidewires and do not debond.

Purpose: The purpose of this study was to comparatively evaluate cement debonding at the time of removal of antibiotic cemented coated nails (ABNs) with cores made with a guidewire ($120), a regular intramedullary nail ($1100) or a threaded rod from a circular frame external fixator set ($60). Methods: A retrospective study was performed on 32 ABNs that had been implanted for long bone infections after intramedullary nailing. All ABNs were manufactured intraoperatively by the treating surgeon using 2 grams of vancomycin and single package of Tobramycin Simplex Cement (Stryker, Kalamazoo, MI). The powder, antibiotics, and polymer were mixed and then injected into an ABN cement mold (Bonesetter Holdings USA). Debonding was assessed at time of removal by the operating surgeon. Rates of cement debonding between the 3 groups were statistically compared. Results: Debonding occurred in 0/12 of the cement nails manufactured with an intramedullary nail, 0/7 threaded rod ABNs, and 6/13 guidewire ABNs. There was a significant difference in the rate of debonding between the 3 groups (P < 0.01). Removal of the remnant cement was accomplished with thin osteotomes, long pituitary rongeurs, or reamers. The canal was visualized using an arthroscope to ensure complete removal of the cement. Conclusion: ABNs fabricated with standard intramedullary nails or threaded rods did not lead to any debonding. Debonding of the cement from the inner core of an antibiotic nail often requires significant effort to remove the remnant cement. Given that threaded rods are often cheaper than guidewires, we recommend that ABNs be fabricated with either threaded rods or interlocking nails, but not guidewires, depending on the level of stability required.

Antibiotic Cement-Coated Interlocked Intramedullary Nails for the Treatment of Infected Nonunion After Intramedullary Nailing.

OBJECTIVE: To evaluate outcomes using an interlocking antibiotic cement-coated nail and culture-specific systematic antibiotics in the treatment of infected nonunion after intramedullary nailing. DESIGN: Retrospective observational cohort study. SETTING: Urban level I trauma center. PATIENTS/PARTICIPANTS: Forty-one nonconsecutive patients who presented to a level I trauma center who underwent interlocked antibiotic nailing for treatment of infected nonunion status after primary intramedullary nailing. OUTCOMES: Eradication of infection, radiographic union by 2-year follow-up. RESULTS: Antibiotic nailing successfully eradicated infection and led to fracture healing in 35 patients (85.4%), while 6 patients (14.6%) had persistent infection and required further surgical treatment. Of the 6 patients who required further treatment, 5 eventually went on to heal with fracture union and eradication of their infection, while 1 required a salvage procedure. Of the 5 patients who eventually went on to heal, 4 of them healed with repeat antibiotic or intramedullary nails, while 1 required segmental resection and bone grafting before healing. CONCLUSIONS: This study suggests that the proposed interlocked antibiotic nailing technique is a viable therapeutic option to eradicate infected nonunion and support fracture healing. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Acute Correction of Femoral Malrotation After Intramedullary Nailing Using an Intraoperative Digital Protractor.

OBJECTIVE:  The goal of the study is to diagnose and accurately correct malrotation of femur fractures after intramedullary (IM) nailing. MATERIALS AND METHODS: An institutional review board (IRB) approved prospective study that was performed at a U.S. level 1 trauma center. After IM nailing of comminuted femur fractures, a computed tomography (CT) scanogram was routinely performed to detect the difference in the postoperative femoral version. Patients with malalignment greater than 15 degrees compared to the contralateral side were informed about the discrepancy and offered to have it acutely corrected. A four-pin technique was used: two Schanz pins were used for measuring angles and two different pins were used to turn and correct the malalignment. The pin in the distal fragment is placed directly under the nail to prevent shortening in comminuted fractures. The nail was unlocked either proximally for retrograde nails or distally for antegrade nails. The Bonesetter Angle application was used as a digital protractor to intraoperatively measure the two reference pins and correct the malrotation. Alternate holes were used for relocking the nail. All patients received a CT scanogram after correction. RESULTS:  19/128 patients with comminuted femoral fractures over five years with malrotations between 18 and 47 degrees were included in the study with an average malrotation of 24.7 + 8 degrees. All patients were corrected to an average of 4.0 +/- 2.1 degrees difference, as compared to the contralateral side (range 0-8). No patients required further surgeries to correct malrotation. CONCLUSION:  Comminuted fractures with malrotation >15 degrees after femoral nailing have an incidence of 15% at our institution. This technique provides an efficient and accurate correction method with the use of an intraoperative digital protractor, avoiding the need for revision IM nailing or osteotomies.

Technical Note on Placement of Low-Profile Triangular Osteosynthesis for Unstable Posterior Pelvic Ring Injuries.

SUMMARY: Triangular osteosynthesis is a technique used to stabilize posterior pelvic ring injuries. Conventional triangular fixation can be problematic for several reasons, including the need for advanced skill sets to place instrumentation, difficulty with pelvic reduction and placing the connecting construct, and prominent instrumentation. The purpose of this study is 2-fold: (1) to describe in detail a technique for lumbopelvic fixation using implants that are easy to connect, allow distraction for complex lumbosacral displacements, and are placed in a location minimizing soft tissue prominence and (2) to present our initial case series using this technique. We present a retrospective review of 18 consecutively treated patients with this technique. Inclusion criteria were patients with complete disruption through the sacrum or sacroiliac joint from blunt trauma (OTA/AO type C injuries). Outcomes included pelvic reduction/malreduction, wound healing, and complications. Fourteen patients underwent unilateral fixation (81%), and 4 patients underwent bilateral fixation (19%). All patients (18 of the 18) had a well-reduced pelvis after fixation. No patient (0%) required a return trip to the operating room for loss of reduction/malreduction, wound breakdown, or implant failure. This study presents an updated technique for a low-profile triangular osteosynthesis construct with straightforward application for unstable posterior pelvic ring injuries. This technique does not require rod bending, results in a consistently more recessed iliac screw and connecting rod, and can be used in a wide variety of unstable posterior pelvic ring injuries, including comminuted sacral fractures, L5/S1 facet fractures, and vertical shear injuries.

Oral administration of voriconazole with surgical fungal plaque debridement for the treatment of sinonasal aspergillosis with cribriform plate lysis in three dogs.

CASE DESCRIPTION: 3 dogs with chronic sinonasal signs (sneezing, nasal discharge, or epistaxis [or a combination of signs]) were examined. CLINICAL FINDINGS: For all 3 dogs, CT revealed variable degrees of nasal turbinate destruction and frontal sinus involvement with cribriform plate lysis. Fungal plaques were detected during rhinoscopy or sinusoscopy. Results of fungal culture (2 dogs) or cytologic examination of a plaque specimen (1 dog) supported a diagnosis of sinonasal aspergillosis. TREATMENT AND OUTCOME: All dogs underwent surgical rhinotomy or sinusotomy (or both) for fungal plaque debridement followed by oral treatment with voriconazole and periodic physical examinations, clinicopathologic analyses, and assessments of serum drug concentrations for a period ≥ 22 weeks. All dogs had considerable to complete reduction of their clinical signs and tolerated voriconazole treatment with minimal adverse effects. Adverse effects included development of reversible neurotoxicosis (associated with high serum voriconazole concentration) and mildly high serum liver enzyme activities. The dosage of voriconazole administered to achieve therapeutic serum concentrations (2.5 to 3.3 mg/kg [1.1 to 1.5 mg/lb], PO, q 12 h) was substantially lower than dosages suggested by previously published studies in dogs. The 3 dogs remained clinically normal or had mild clinical signs after voriconazole discontinuation for follow-up times of 6 to 15 months. CLINICAL RELEVANCE: Findings in these 3 dogs indicated that surgical fungal plaque debridement followed by oral treatment with voriconazole may be an effective treatment option for dogs with sinonasal aspergillosis and cribriform plate lysis. Further evaluation of this treatment regimen with repeated CT examinations and longer follow-up times is warranted.