Fibular head transfixion wire and its relationship to common peroneal nerve: cadaveric analysis.

Proximal tibio-fibular joint is routinely stabilised during leg lengthening, peri-articular fractures and deformity corrections of tibia. Potential injury to the common peroneal nerve at the level of the fibula head/neck junction during wire insertion is a recognised complication. Previous studies have mapped the course of the common peroneal nerve and its branches at the level of the fibular head, and guidelines are published regarding placement of proximal tibial wires. This study aims to relate the course of the common peroneal nerve to the placement of a lateral insertion fibula head transfixion wire. Standard 1.8-mm Ilizarov 'olive' wires were inserted in the fibula head of 10 un-embalmed cadaveric knees. Wires were inserted percutaneously to the fibula head using surface anatomy landmarks and palpation technique. The course of the common peroneal nerve was then dissected. Distances from wire entry point to the course of the common peroneal nerve were measured post-wire insertion. The mean distance of the common peroneal nerve from the anterior aspect of the broadest point of the fibular head was 24.5 mm (range 14.2-37.7 mm). Common peroneal nerve was seen to cross the neck of fibula at a mean distance of 34.8 mm from the tip of fibula (range 21.5-44.3 mm). Wire placement was found to be on average, 52 % of the maximal AP diameter of the fibula head and 64 % of the distance from tip of fibula to the point of nerve crossing fibula neck. When inserting a fibula head transfixion wire, care must be taken not to place wire entry point too distal or posterior on the fibula head. Observing a safe zone in the anterior half of the proximal 20 mm of the fibula head would avoid injury to the nerve. In cases where palpation of fibula is difficult due to patient habitus, we recommend consideration of the use of fluoroscopic guidance during wire transfixion of the proximal tibio-fibular articulation to avoid wire insertion too distally and subsequent potential nerve injury.

Cadaveric analysis of capsular attachments of the distal femur related to pin and wire placement.

OBJECTIVES: Septic arthritis following intra-capsular penetration of the knee by external fixation devices is a complication of traction/fixation devices inserted in the lower extremity [1,2]. The authors were unable to find reference to or exact measurements of the capsular attachments relating to the distal femur documented in the current literature. This study aimed to demonstrate the capsular attachments and reflections of the distal femur to determine safe placements of wires or traction devices. METHODS: The attachments of the capsule to the distal femur were measured in 10 unembalmed cadaveric knees. Capsular attachments were measured anteriorly at the maximal extension of the supra-patella pouch. Medially and laterally measurements were expressed as percentages related to the maximal AP diameter of the distal femur. RESULTS: Mean distance from the centre of the anterior part of the notch to the superior fold was 79.5mm (Range 48.1-120.7 mm). The medial capsular reflections measured in a plane from the adductor tubercle to the anterior edge of the medial femoral condyle demonstrated the capsular reflection was attached an average of 57% back from the anterior edge (Range 41-74%). Laterally the capsular reflections on a line drawn from the maximal diameter in the sagittal plane were attached an average of 48% from the anterior reference point (Range 33-57%). Measuring the reflections at 45 degrees to the long axis of the femur in the sagittal plane the attachment was an average of 51% from the anterior reference point. CONCLUSIONS: Capsular reflections varied among specimens. Medially the capsule attachment was up to 74% of diameter of distal femur at the level of the adductor tubercle. Therefore, the insertion of distal femoral traction pins or similar should be placed proximal to the adductor tubercle and no further than 25% of the distance to the anterior cortex. Care is also needed to ensure pins do not travel to exit too anteriorly on the lateral side as capsular attachments were found to be up to a distance 48% of the diameter of the femur from anterior reference point. Distal condylar extra-articular fixation with Schanz screws is feasible if orientated in the oblique plane.

The Post-Levator Aponeurosis Fat Pad.

PURPOSE: To examine the post-aponeurotic space and to confirm and define the presence of a post-aponeurosis fat-pad. METHODS: Experimental anatomic study. Nineteen-orbits from 10 freeze-preserved, unembalmed cadavers of caucasian subjects. In 12 orbits of 7 cadavers, a transconjunctival dissection of the everted upper eyelid was undertaken. Müller's muscle (MM) and conjunctiva were dissected as a composite flap exposing the posterior surface of the aponeurosis (LA) and the commencement of the levator palpebrae superioris (LPS) muscle. Anatomical localisation was agreed by 2 senior surgeons and an anatomist (VM). In the remaining 7 orbits a 1cm central upper eyelid wedge-excision was paraffin-embedded and studied histologically. RESULTS: Nineteen upper-eyelids from 10 freeze-preserved, unembalmed caucasian cadavers (5-male, 5-female, mean age 80.9; range 67-91 years) were studied. Of 12 eyelids of 7 cadavers, dissected and macroscopically evaluated, a fat-pad was identified in the post-aponeurotic space of all eyelids. Of these, 8 (66%) were predominantly diffuse. The remainder, mixed diffuse-discrete. All 4 of the latter category appeared multi-lobular. The fat-pad was seen to lie predominantly centro-medially, overlying MM, extending superiorly beyond the LA to lie posterior to LPS. Of the 7 upper eyelid wedge-excisions examined microscopically, a fat-pad was identified in all post-aponeurotic spaces, lying between 2 distinct tracts of smooth muscle. The anterior smooth muscle tract was intimately related to the posterior aspect of the LA, in keeping with the posterior smooth muscle layer of the aponeurosis. The posterior smooth muscle tract was in keeping with MM, thicker than the anterior layer, multi-layered and in 6 of 7 eyelids, interspersed with fat. CONCLUSIONS: We confirm and describe a distinct layer of fat in the post-aponeurotic space, consistently found between MM and the posterior smooth muscle layer of the aponeurosis. We refer to this as the post-aponeurosis fat-pad. These findings provide further anatomical detail for the surgeon undertaking blepharoptosis surgery, who may, in some cases, mistake the presence of fat in this space either for the pre-aponeurotic fat-pad, or for degenerative changes within MM that lies deep to it.

Ciliated foregut cyst of the gallbladder. A diagnostic challenge and management quandary.

Ciliated foregut cysts are rare anomalies due to aberrant embryological development. Only a small number of gallbladder ciliated foregut cysts have been reported. We report the case of a 29-year-old woman presenting with epigastric pain associated with diarrhoea and vomiting, who was found to have raised serum bilirubin levels and abnormal liver function tests. Following a diagnostic pathway including abdominal ultrasound, magnetic resonance cholangiopancreatography and endoscopic ultrasound the gallbladder cyst was provisionally diagnosed to be a cyst arising from the cystic duct or a duplicated gallbladder. A laparoscopic cholecystectomy was carried out and histopathology identified a ciliated foregut gallbladder cyst. The postoperative course was uneventful. In this report we offer what we believe to be an optimal diagnostic pathway and therapeutic strategy for this rare congenital cyst.

Dissection of soft-preserved cadavers in the training of gynaecological oncologists: report of the first UK workshop.

OBJECTIVE: To assess the surgical anatomy knowledge of gynaecological oncology (GO) trainees and to evaluate the impact of a cadaveric dissection course on postgraduate surgical training. METHODS: An intensive 3-day cadaveric dissection course with illustrated lectures and supervised dissection, with a multiple-choice questionnaire (MCQ) on surgical anatomy at the beginning and end of the course was organised in the Anatomy Facility of a London Medical School. Each cadaver was embalmed with a mixture of alcohol, phenol and glycerol ("soft-preserved") rather than fixed in formalin, to more closely preserve in vivo conditions of the body. There were ten dissecting delegates, two per cadaver. The delegates dissected the abdomen and pelvis with the emphasis on surgical approaches rather than the classical descriptive anatomy approaches. Delegates also completed a course evaluation. RESULTS: Without negative marking, the mean initial MCQ score was 57%, and final mean score 64%. With negative marking, the mean initial score was 43%, and mean final score 53%. Delegates rated the course highly, would recommend it to other trainees and considered that such a course should be incorporated into subspecialty training. CONCLUSION: The surgical anatomy knowledge of subspecialty trainees was weak but improved as a result of the dissection course. The most positive finding was the course evaluation. Postgraduate surgical training in GO would likely be enhanced by, and arguably requires, cadaveric dissection. "Soft-preserved" rather than formalin-fixed cadavers should be used.