Comparison of the Effects of Botulinum Toxin Doses on Nerve Regeneration in Rats with Experimentally Induced Sciatic Nerve Injury.

This study was designed to compare the effects of various doses of botulinum neurotoxin A (BoNT/A) on nerve regeneration. Sixty-five six-week-old rats with sciatic nerve injury were randomly allocated to three experimental groups, a control group, and a sham group. The experimental groups received a single session of intraneural BoNT/A (3.5, 7.0, or 14 U/kg) injection immediately after nerve-crushing injury. The control group received normal intraneural saline injections after sciatic nerve injury. At three, six, and nine weeks after nerve damage, immunofluorescence staining, an ELISA, and toluidine blue staining was used to evaluate the regenerated nerves. Serial sciatic functional index analyses and electrophysiological tests were performed every week for nine weeks. A higher expression of GFAP, S100ß, GAP43, NF200, BDNF, and NGF was seen in the 3.5 U/kg and 7.0 U/kg BoNT/A groups. The average area and myelin thickness were significantly greater in the 3.5 U/kg and 7.0 U/kg BoNT/A groups. The sciatic functional index and compound muscle action potential amplitudes exhibited similar trends. These findings indicate that the 3.5 U/kg and 7.0 U/kg BoNT/A groups exhibited better nerve regeneration than the 14 U/kg BoNT/A and control group. As the 3.5 U/kg and the 7.0 U/kg BoNT/A groups exhibited no statistical difference, we recommend using 3.5 U/kg BoNT/A for its cost-effectiveness.

Bilateral Atypical Femoral Fractures after Bisphosphonate Treatment for Osteoporosis: A Literature Review.

INTRODUCTION: This literature review aimed to investigate the incidence, anatomical concerns, etiology, symptoms, diagnostic tools, management, and prognosis of bisphosphonate (BP)-associated bilateral atypical femoral fractures (AFFs). METHODS: The PubMed, Cochrane Library, Web of Sciences, and CINAHL databases were searched up to 20 March 2022. All cases of bilateral AFFs were included, excluding those without any bisphosphonate treatment information and those in which the femoral fracture did not precisely fit into the diagnostic criteria for AFF. RESULTS: We identified 43 patients with bilateral AFFs associated with BP use and conducted a comprehensive analysis. Among 43 patients, 29 (67%) had prodromal symptoms. Regarding the simultaneity of fracture, 21 cases (49%) occurred simultaneously, and 22 cases (51%) occurred sequentially. Alendronate was the most commonly used BP treatment (59%). Regardless of the medication type, BP intake duration was more than 5 years in 77%. The initial diagnosis was performed using X-rays in all cases. A total of 53% of patients had complete fractures, and all patients underwent surgical treatment. Among the remaining patients with incomplete fractures, 18% and 29% received surgical and medical treatments, respectively. After BP discontinuation, teriparatide was most commonly used (63%). CONCLUSIONS: The careful evaluation of relevant imaging findings in patients with thigh/groin pain allows the identification of early incomplete fractures and timely management. Since the rate of contralateral side fractures is also high, imaging studies should be performed on the asymptomatic contralateral side.