The morphologic and morphometric features of the triquetrum.

Fractures of the triquetrum are the second most common form of isolated carpal bone fracture after the scaphoid. However, data on triquetrum morphology and morphometry are sparse. The aim of this study was to describe the morphology of triquetrum using anatomical landmarks, evaluate its morphometric features, and determine its vascular entry points. The morphological and morphometrical features of 87 adult dry triquetral bones (39 left, 48 right) were determined by measuring length, width and thickness. The number and locations of nutrient foramina wider than 0.5 mm were recorded. Mean length, width and thickness were 17.37 mm (range, 14.26-22.13), 12.65 mm (range, 10.37-15.85) and 11.41 mm (range, 8.98-18.23), respectively. The facet articulating with the pisiform was oval in 40 bones, round in 8 and amorphous (neither round nor oval) in 39. The mean length of the interarticular ridge was 7.09 ± 0.9 mm. The mean number of nutrient foramina was significantly greater on the dorsal than on the other aspects. The dorsal predominance of nutrient foramina makes the bone weaker in the dorsal region, which could explain why fractures are more common in this region. Also, the dorsal aspect is rich in blood supply, which could explain why avascular necrosis is less common in triquetral fractures. As most of the vascularization is on the dorsal side, there is need for caution when performing triquetrum surgery. LEVEL OF EVIDENCE: Level 2.

Re-defining the anatomical structures for blocking the nerves in adductor canal and sciatic nerve through the same injection site: an anatomical study.

PURPOSE: The aim of this study is to re-define the anatomical structures which are important for blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site. We also aimed to investigate the spread of the anesthetic toward the areas in which the mentioned nerves lie on cadavers. METHODS: This study was performed on 16 lower extremities of formaldehyde-embalmed eight adult cadavers. The anatomy of adductor canal, courses of the nerves within the canal and the relationships of the saphenous, medial femoral cutaneous, medial retinacular, posterior branch of the obturator and sciatic nerves with each other and with the fascial compartments were investigated. Transverse sections that crossed the superior border of vastoadductor membrane were taken to reach the sciatic nerve in the shortest way. Colored latex was injected to demonstrate the anesthetic blockage of the targeted nerves. The structures along the needle's way were investigated. RESULTS: The saphenous, medial femoral cutaneous and at its distal part posterior branch of the obturator nerve were colored with latex within the adductor canal. The nerve to vastus medialis (in other words, the medial retinacular nerve) lay beneath the fascia of vastus medialis and did not enter the adductor canal. There was a fascial plane which did not allow the passage of colored latex toward the sciatic nerve. To traverse this fascial structure, it was found out to be necessary to insert the needle perpendicular to both the vertical and transverse axes of the thigh and then advance it along 2/3 of diameter of the thigh. Thus, the colored latex was observed to fill the compartment where the sciatic nerve lay within. CONCLUSIONS: Blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site seems anatomically possible without injuring any neurovascular structures.

The medial and lateral epicondyle as a reliable landmark for intra-operative joint line determination in revision knee arthroplasty.

OBJECTIVES: The purpose of this study was to develop an accurate, reliable and easily applicable method for determining the anatomical location of the joint line during revision knee arthroplasty. METHODS: The transepicondylar width (TEW), the perpendicular distance between the medial and lateral epicondyles and the distal articular surfaces (DMAD, DLAD) and the distance between the medial and lateral epicondyles and the posterior articular surfaces (PMAD, DLAD) were measured in 40 knees from 20 formalin-fixed adult cadavers (11 male and nine female; mean age at death 56.9 years, sd 9.4; 34 to 69). The ratios of the DMAD, PMAD, DLAD and PLAD to TEW were calculated. RESULTS: The mean TEW, DMAD, PMAD, DLAD and PLAD were 82.76 mm (standard deviation (sd) 7.74), 28.95 mm (sd 3.3), 28.57 mm (sd 3), 23.97 mm (sd 3.27) and 24.42 mm (sd 3.14), respectively. The ratios between the TEW and the articular distances (DMAD/TEW, DLAD/TEW, PMAD/TEW and PLAD/TEW) were calculated and their means were 0.35 (sd 0.02), 0.34 (sd 0.02), 0.28 (sd 0.03) and 0.29 (sd 0.03), respectively. CONCLUSION: This method provides a simple, reproducible and reliable technique enabling accurate anatomical joint line restoration during revision total knee arthroplasty.Cite this article: B. Ozkurt, T. Sen, D. Cankaya, S. Kendir, K. Basarir, Y. Tabak. The medial and lateral epicondyle as a reliable landmark for intra-operative joint line determination in revision knee arthroplasty. Bone Joint Res 2016;5:280-286. DOI: 10.1302/2046-3758.57.BJR-2016-0002.R1.

The location of the obturator nerve: a three-dimensional description of the obturator canal.

Satisfactory analgesia cannot be achieved in every obturator nerve block. To attempt to improve the success rate of obturator nerve block, this study describes the detailed anatomy of the obturator region and canal. Eleven (5 female and 6 male) cadavers, totally 22 sides were dissected. Anatomical positions of the structures entering and leaving the canal were defined. The position of the obturator nerve and its branches and their relation with the obturator artery, vein, and with the internal iliac and femoral veins were investigated. A mould of the canal and a model were created. Detailed measurements were performed on the cadavers and models. The obturator canal was in the shape of a funnel compressed from superior to inferior, with anterior and posterior openings. At the entrance of the canal, the nerve lay superiorly; the artery was in the middle, and the vein lay inferiorly. The obturator nerve ran close to the lateral wall of the obturator canal. The distance of lateral wall of obturator canal to the median plane was 41.4 +/- 1.1 mm. After leaving the canal, the nerve lay laterally while the anterior branch of the artery was medial. A venous plexus lay between the two structures. The presence of the branches of the obturator artery and vein alongside the obturator nerve may increase the risk of injury to these structures during anaesthetic procedures. The anterior division of the obturator nerve has a close relationship with these vessels. To provide complete analgesia, the obturator nerve should be blocked in the obturator canal or at its external orifice.

Detailed anatomy of accessory obturator nerve blockade.

BACKGROUND: The accessory obturator nerve (AON) often innervates the hip joint and adductor longus. The AON is present in 10-30% of patients, and thus it is clinically important that it is also considered during obturator nerve (ON) blockade. METHODS: The study was performed on 12 cadavers (24 body-sides) and the AON beginning from the lumbar plexus was observed. The needle was classically penetrated into the ON to gain access to the AON and upon definition of detailed AON anatomy, morphometric measurements were conducted. In addition, novel maneuvers used in the study were described. RESULTS: Throughout the dissections, the AON was detected on three sides (12.5%) and the mean AON- pubic tubercle distance was measured as 4.0 cm. The needle was withdrawn and positioned medially and almost parallel to the skin. It was then advanced through the superior pubic ramus to reach the AON. CONCLUSION: Owing to its anatomical structure, the AON can be easily accessed during classical ON blockade using the maneuvers described here. Further clinical studies are needed to investigate if supplementing ON blockade with AON blockade might improve the clinical efficiency and quality of the blockade.

The effects of incremental brightness and contrast adjustments on radiographic data: a quantitative study.

OBJECTIVES: To determine the border level of brightness and contrast changes in order to prevent the loss of originality of the quantitative data on digital dental radiographs. METHODS: After measuring the baseline mean grey values (MGVs) of a fixed region of interest on the alveolar bone and an aluminium step wedge, incremental brightness and contrast adjustments were performed on a digital periapical radiograph. The distribution of the data was analysed to investigate the significance of the changes on radiodensitometric data after incremental increase of brightness and contrast. RESULTS: The original MGVs were easily retrieved after brightness adjustments; however, the contrast increase led to more complicated density changes. The originality of the data was saved up to 50 units of contrast increase, but further than this limit, significant radiodensitometric changes occurred. CONCLUSIONS: Contrast adjustments should be performed cautiously when making quantitative analyses on the digital radiographs.