PLGA-PEG-PLGA hydrogel with NEP1-40 promotes the functional recovery of brachial plexus root avulsion in adult rats

Adult brachial plexus root avulsion can cause serious damage to nerve tissue and impair axonal regeneration, making the recovery of nerve function difficult. Nogo-A extracellular peptide residues 1-40 (NEP1-40) promote axonal regeneration by inhibiting the Nogo-66 receptor (NgR1), and poly (D, L-lactide-co-glycolide)-poly (ethylene glycol)-poly (D, L-lactide-co-glycolide) (PLGA-PEG-PLGA) hydrogel can be used to fill in tissue defects and concurrently function to sustain the release of NEP1-40. In this study, we established an adult rat model of brachial plexus nerve root avulsion injury and conducted nerve root replantation. PLGA-PEG-PLGA hydrogel combined with NEP1-40 was used to promote nerve regeneration and functional recovery in this rat model. Our results demonstrated that functional recovery was enhanced, and the survival rate of spinal anterior horn motoneurons was higher in rats that received a combination of PLGA-PEG-PLGA hydrogel and NEP1-40 than in those receiving other treatments. The combined therapy also significantly increased the number of fluorescent retrogradely labeled neurons, muscle fiber diameter, and motor endplate area of the biceps brachii. In conclusion, this study demonstrates that the effects of PLGA-PEG-PLGA hydrogel combined with NEP1-40 are superior to those of other therapies used to treat brachial plexus nerve root avulsion injury. Therefore, future studies should investigate the potential of PLGA-PEG-PLGA hydrogel as a primary treatment for brachial plexus root avulsion.

STORAGE MEDIUM FOR AVULSED TEETH: A LITERATURE REVIEW

Avulsion injury is one of the most severe types of traumatic dental injuries. Following avulsion, periodontal ligament tissues are injured and the vessels and nerves of the pulp rupture at the apical foramen which causes pulp necrosis. In studies it was reported that the key to retention of the knocked-out teeth was to maintain the viability of the periodontal ligament. Storage media plays an important role in preserving the viability of PDL cells during extra alveolar time. This article highlights the different storage medias available for avulsed teeth, along with their merits and demerits.

Ulnar Parametacarpal Flap for Small Finger Avulsion Injury

In difficult cases of replantation following small finger avulsion injury, in which amputation occurs at the proximal interphalangeal joint, the ulnar parametacarpal island flap, rotated 180° (propeller flap), can be used as an alternative method for covering a skin defect of the proximal phalanx. This flap can prevent metacarpophalangeal joint dysfunction and additional finger shortening. We propose the use of an ulnar parametacarpal flap for this purpose and report the outcomes of two successful cases treated with this method and followed up for 12 months.

Post road traffic accident one-month old, extra-large heel defect coverage by delayed reverse sural artery flap: an interesting case report

Post road traffic accident (RTA) complete heel avulsion injury is not very common, but once it happened, it is very challenging to plastic and reconstructive surgeon to reconstruct the total heal avulsion defect. There is paucity of soft tissue in the region of foot, ankle and lower one third of leg. Although the micro vascular free flap reconstruction is gold standard for reconstruction of large heel defect but not feasible most of the time. Reverse sural artery flap (RSAF) is a workhorse flap for reconstruction of heel and lower 1/3rd leg defect. Here we reported a case of 28 years old young man, who had road traffic accident and sustained complete right heel avulsion injury with calcaneal and right tibia bone fracture. Patient was presented to author one month later after the injury with extra-large infective right heel defect size 15×12 cm with k-wires in exposed calcaneal bone. Patient’s surgery was done in two stages. Delayed RSAF survived completely and well settled in our case.

CLASSIFYING ISCHIAL TUBEROSITY AVULSION FRACTURES BY OSSIFICATION STAGE AND TENDON ATTACHMENT

Background: Currently, there is no classification system for ischial tuberosity avulsion fractures. Hypothesis/Purpose: To provide a new classification system for ischial tuberosity fractures based on the ossification pattern of the apophysis. Methods: We performed a retrospective records review of patients diagnosed with ischial tuberosity avulsion fractures at our institution from 2008 to 2018. Skeletal maturity (Modified Oxford score [MOS], Risser score), fracture type, size, and displacement were recorded based on initial injury radiographs. We reviewed a large series of pelvic CT and MRI scans from patients aged 10-19 years old to assess the ossification pattern and tendinous attachments of the ischial tuberosity. Pelvic CT review demonstrated a reproducible 5-stage pattern of ossification spanning the age of 13-19 years for males and 12-17 years for females (Figure 1). Review of available CTs and MRIs indicated that the semimembranosus attaches at the most lateral ossification center, followed by the conjoint tendon and adductor magnus as one moves medially (Figures 1). We created a classification system based on location of the ischial tuberosity avulsion fracture: Type 1 (lateral – semimembranosus and conjoint tendons) or Type 2 (complete – semimembranosus, conjoint, and adductor magnus tendons). An A or B descriptor was then added to distinguish minimally displaced (<1 cm) and displaced (≥1 cm) fractures, respectively (Figure 2). Results: We identified 45 ischial tuberosity fractures. Mean age was 14.4 years (range, 10.3–18). Males accounted for 82% of the cohort. Type 1 fractures accounted for 47% of cases and 53% were classified as Type 2. Type 1 fractures were associated with younger age chronological age (p=0.001), lower MOS (p=0.002), lower Risser score (p=0.002), less displacement (p=0.001), and smaller size (p<0.001), when compared with Type 2 fractures (Table 1). Of the 45 patients, 18 had >6 month follow-up with 56% going on to non-union. Non-union was associated with greater displacement (p=0.016) and size (p=0.027). When comparing union rates by fracture location, 33% of Type 1 fractures progressed to non-union, while 78% percent of Type 2 suffered a non-union; however, this difference did not reach statistical significance (p=0.153) (Table 2). Conclusion: In younger patients (ages 13-15 years), the lateral ossification centers of the ischial tuberosity, at which the hamstrings attach, are at risk for isolated avulsion injury. However, in older patients (16-18 years), coalescence of the hamstring and adductor magnus ossification centers predispose patients to a combined avulsion injury consisting of a larger fragment and with greater displacement. [Figure: see text][Figure: see text][Table: see text][Table: see text]