Anteroinferior versus superior plating techniques for displaced midshaft clavicle fractures: A retrospective single centre cohort study from Northern Nigeria.

BACKGROUND: Clavicle fractures are common injuries accounting for up to 5% of all fractures in adults. Most clavicle fractures heal well with nonoperative treatment, some however, require surgical intervention especially when they are displaced. While plating remains the most popular and most successful method of clavicle fixation; the optimal position of the plate is yet to be agreed upon. PURPOSES: The purpose of this study was to compare the functional outcomes of displaced clavicle fractures fixed with superior and anteroinferior plating techniques. PATIENTS AND METHODS: This retrospective cohort study of 69 patients (45 males and 24 females) was carried out between January 2014 and December 2018 at a government orthopaedic hospital in north-western part of Nigeria. The study involved all consecutive patients who sustained a displaced mid-shaft clavicle fracture and had open reduction and internal fixation (ORIF) with either superior plating (SP) or anterior-inferior plating (AIP) and were followed up for at least one year. Data analyzed include: age, sex, laterality, mode of injury, the time from initial injury to surgery, type of plate used, position of the plate, union rate, functional outcome and peri-operative complications. RESULTS: Fourty-two patients had SP and twenty seven patients had AIP. Fourty one (97.6%) patients had fracture union in SP group while all the twenty seven patients (100%) in the AIP group had fracture union. The mean QuickDASH scores was 3.2 ± 4.6 and 3.6 ± 4.7 in AIP and SP groups respectively. There was no significant difference in the union rates and functional outcome between the two groups. CONCLUSION: Both superior and anteroinferior plating techniques are safe and effective in the surgical management of displaced mid-clavicle fractures. LEVEL OF EVIDENCE: Level 3, retrospective cohort study.

Arthroscopic procedure for revision of failed isolated bucket-handle meniscal tear repair.

Surgery failure rates average 20% following bucket-handle meniscal tears (BHMT) repairs in the literature. Achieving the healing of BHMT is difficult, how much more in revision cases. Some authors have reported higher failure rates especially in the early postoperative period and in younger patients. Multiple techniques and augmentations to enhance biologic healing and reduce failure rate have been described. We describe an arthroscopic technique for successfully revising a failed BHMT repair using the technique of percutaneously releasing the posterior fibers of the medial collateral ligament to provide adequate space for arthroscopy, refreshing of the torn surfaces, bed trephination before reduction and repair. We concluded that a combined double-level inside out vertical sutures with horizontal reinforcement and all-inside technique using fast fix give anatomic reduction, stable fixation, surface contact, and increased potential for biologic healing in failed BHMT repairs. Coupled with adequate rehabilitation programs, this technique has reduced the failure rate in revision cases and enhances early return to sport.

Major venom proteins of the fire ant Solenopsis invicta: insights into possible pheromone-binding function from mass spectrometric analysis.

Proteins in the venom of the fire ant Solenopsis invicta have been suggested to function in pheromone binding. Venom from queens and workers contains different isoforms of these proteins, consistent with the differing pheromones they secrete, but questions remain about the venom protein composition and glandular source. We found that the queen venom contains a previously uncharacterized pheromone-binding protein paralogue known as Sol i 2X1. Using imaging mass spectrometry, we located the main venom proteins in the poison sac, implying that pheromones might have to compete with venom alkaloids for binding. Using the known structure of the worker venom protein Sol i 2w, we generated three-dimensional homology models of the worker venom protein Sol i 4.02, and of the two main venom proteins in queens and female alates, Sol i 2q and Sol i 2X1. Surprisingly, the models show that the proteins have relatively small internal hydrophobic binding pockets that are blocked by about 10 amino acids of the C-terminal region. For these proteins to function as carriers of hydrophobic ligands, a conformational change would be required to displace the C-terminal region, somewhat like the mechanism known to occur in the silk moth pheromone-binding protein.