Late postnaupliar development of the freshwater copepods Lovenula falicifera and Metadiaptomus colonialis (Calanoida: Diaptomidae) from South Africa

The life cycle of calanoid copepods consists of eggs hatching into nauplii (6 stages) which then moult into copepodids (5 stages), followed by the final moult into the adult female and male. The family Diaptomidae contains two subfamilies, Diaptominae and Paradiaptominae, with paradiaptomids almost exclusively consisting of African taxa. The copepodid stages III, IV and V were described for some freshwater diaptomine genera (i.e., Eudiaptomus Kiefer, 1932, Aglaodiaptomus Light, 1938, Skistodiaptomus Light, 1939, Leptodiaptomus Light, 1938, Megadiaptomus Kiefer, 1936 and Diaptomus Westwood, 1836). Copepods collected from Turfloop Dam, South Africa, with a plankton net were fixed and preserved in 70% ethanol. Calanoid copepods were studied under stereo- and light microscopes, using the wooden slide technique and features drawn. Examined specimens were identified as the copepodid stages of two African species, Lovenula falcifera (Lovén, 1845) and Metadiaptomus colonialis (van Douwe, 1914). Copepodids of the two species can be distinguished by their body size and the structure and size of the maxillipeds. The description and illustrations of three postnaupliar stages (CoIII, CoIV and CoV) are provided for both species. The identification of different stages is based on the number of urosomites, antennule development, the segmentation of legs 1–4, and the development of the fifth leg. These copepodids are compared with those of other described diaptomid genera.

Modified Tension-Slide Technique for Endoscopy-Assisted Flexor Hallucis Longus Tendon Transfer

The rupture of the Achilles tendon (AT) usually occurs in high-caliber athletes, but low-demand patients are also are risk, mainly if they are under corticoids or quinolones. The diagnosis of the AT rupture is usually neglected, and this could result in a worse prognosis for the patient if not treated in an appropriate time. For these patients or for those with high surgical risk, an option of minimally invasive surgery remains attractive. Classical techniques consist of direct repair or augmentation with the tendon of the flexor hallucis longus as well as nonanatomical tendon transfers which can generate issues with the donor site. We present a pioneering technique that is analogous to that used for the surgical treatment of distal rupture of the biceps tendon, which consist of a transfer technique of flexor hallucis longus by extracortical fixation interference screw associated to a direct tendon reinsertion performed through a bone tunnel on the superior and posterior aspect of the calcaneus using an extracortical drilling system and an interference screw within the calcaneal tunnel. The arthroscopic approach may be technically challenging, and a high-level of arthroscopic skills are required to complete the procedure but after a learning curve it represents a feasible a safe technique. Levels of Evidence:Therapeutic, Level IX: Evidence from opinion of authorities and/or reports of expert committee

The"slide technique"-a novel free-hand method of subaxial cervical pedicle screw placement

Background: Cervical Pedicle Screw(CPS) placement is a challenging work due to the high risk of neurovascular complications. Although there have been several different free-hand or navigation assisted techniques for CPS placement, perforations may occur during screw insertion, especially lateral perforation. The objective of this manuscript is to describe a novel free-hand technique for subaxial CPS placement (C3–C7) and to evaluate if it decreases the chances of perforation.Methods: Thirty-two patients undergoing surgery with CPS instrumentation (C3–C7) at our institute between June 2017 and December 2018 were included in this study. All the patients had cervical trauma, and pedicle screw insertion was performed according to the free-hand “slide technique”. The lamina, lateral mass and facet joint of the target area were exposed and the optimal entry point was found on the lateral mass posterior surface. A pedicular probe was then inserted and gently advanced. During the pedicle probe insertion, the cortex of the medial margin of the pedicle acted as a slide to permit the safe insertion of the screw. If the pedicle screw pathway was intact, the screw of the appropriate size was carefully placed. Three-dimensional (3D) CT imaging reconstruction was performed in all the patients after surgery, and screw perforations were graded with the Gertzbein-Robbins classification.Results: A total of 257 CPSs (C3-7) were inserted, of which 41 CPSs were in C3, 61 CPSs were in C4, 55 CPSs were in C5, 53 CPSs were in C6, and 47 CPSs were in C7. The diameter and length of CPSs were 3.5 mm and 22-26 mm respectively. According to the Gertzbein-Robbins classification, grade 0, 231 screws; grade 1, 19 screws; and grade 2, 7 screws. No neurovascular complications occurred stemming from malpositioning of pedicle screws. Among perforated screws (26 screws), there were 16 lateral perforations, 5 medical perforations, and 4 inferior perforations.Conclusions: The initial usage result shows the “slide technique” is a safe, effective and cost-effective technique for pedicle screw placement in the cervical spine. This is the first report of such a technique. We recommend its use though further studies are needed.