Allograft use in anterior cruciate ligament reconstruction surgery: a review of the current literature

Anterior cruciate ligament reconstruction (ACLR) surgery plays an important role in restoring stability and function to the knee joint following ACL rupture. Owing to an increase in activity levels and sports participation, ACLR has become one of the most commonly performed procedures world-wide. Graft choice may influence clinical outcomes, and therefore the optimal graft remains widely debated. Whilst, historically, autograft tissue has been the preferred choice, the past decade has seen a steady increase in the popularity of allografts. This demand is partly driven by improvements in graft availability, procurement processes and safety; but more importantly a desire to eliminate issues related to donor site morbidity from graft harvest. Despite this, there remains controversy surrounding the use of allograft in ACLR surgery, with much of the literature demonstrating conflicting evidence on functional and survivorship outcomes. In this article we review the current literature surrounding allograft use in ACLR, from the biology of allograft integration, through to outcomes in clinical practice.     

Minocycline differentially modulates human spatial memory systems

Microglia play a critical role in many processes fundamental to learning and memory in health and are implicated in Alzheimer’s pathogenesis. Minocycline, a centrally-penetrant tetracycline antibiotic, inhibits microglial activation and enhances long-term potentiation, synaptic plasticity, neurogenesis and hippocampal-dependent spatial memory in rodents, leading to clinical trials in human neurodegenerative diseases. However, the effects of minocycline on human memory have not previously been investigated. Utilising a double-blind, randomised crossover study design, we recruited 20 healthy male participants (mean 24.6 ± 5.0 years) who were each tested in two experimental sessions: once after 3 days of Minocycline 150 mg (twice daily), and once 3 days of placebo (identical administration). During each session, all completed an fMRI task designed to tap boundary- and landmark-based navigation (thought to rely on hippocampal and striatal learning mechanisms respectively). Given the rodent literature, we hypothesised that minocycline would selectively modulate hippocampal learning. In line with this, minocycline biased use of boundary- compared to landmark-based information (t₉₈₀ = 3.140, p = 0.002). However, though this marginally improved performance for boundary-based objects (t₉₈₀ = 1.972, p = 0.049), it was outweighed by impaired landmark-based navigation (t₉₈₀ = 6.374, p < 0.001) resulting in an overall performance decrease (t₉₈₀ = 3.295, p = 0.001). Furthermore, against expectations, minocycline significantly reduced activity during memory encoding in the right caudate (t₉₇₇ = 2.992, p = 0.003) and five other cortical regions, with no significant effect in the hippocampus. In summary, minocycline impaired human spatial memory performance, likely through disruption of striatal processing resulting in greater biasing towards reliance on boundary-based navigation.Subject terms: Microglia, Hippocampus     

Grading Facial Nerve Function Following Combined Static and Mimetic Surgical Techniques

Objective To present a grading scale to assess the functional recovery of the facial nerve in patients who have undergone mimetic and static surgical techniques for facial reanimation. Study design This is a proposed new facial nerve grading system that will be demonstrated with specific case presentations. All patients underwent a variety of neural grafting, microvascular free-flap reconstruction, or surgical static procedures. Results The proposed facial nerve grading scale is one that has not been described previously in the literature and is applicable to a unique patient population. Its ease of use in this patient population will allow otolaryngologists to assess facial recovery accurately and quickly in cases where the facial nerve is not anatomically intact. Conclusion The proposed facial recovery grading scale provides an efficient means of grading facial recovery for a unique group of patients who previously could not be followed. The proposed scale is practical and easy to use in a clinical setting.