Anatomical landmarks for ankle block

We aimed to describe anatomical landmarks to accurately locate the five nerves that are infiltrated to accomplish anaesthesia of the foot in an ankle block. Twenty-four formaldehyde-fixed cadaveric ankles were studied. Photographs of cross sections of the frozen legs, cut at a horizontal plane across the most prominent points of the medial and lateral malleoli, were analysed. The curvilinear distance from the most prominent point of the closest malleolus to each of the five cutaneous nerves and their depth from the skin surface were measured. Sural, tibial, deep peroneal, saphenous and medial dorsal cutaneous nerves were located 5.2 ± 1.3, 9.2 ± 2.4, 7.4 ± 1.9, 2.8 ± 1.1, 2.1 ± 0.6 mm deep to the skin surface. The curvilinear distances from the medial malleolus to the tibial, deep peroneal and saphenous nerves were 32.5 ± 8.9, 62.8 ± 11.1 and 24.4 ± 7.9 mm, respectively. The curvilinear distances from the lateral malleolus to the sural and medial dorsal cutaneous branches of superficial peroneal nerves were 27.9 ± 6.3 and 52.7 ± 7.3 mm, respectively. The deep peroneal nerve was found between the tendons of the extensor hallucis longus and the extensor digitorum longus in the majority of specimens, while the medial dorsal cutaneous nerve was almost exclusively found on the extensor digitorum longus tendon. The sural and tibial nerves were located around halfway between the most prominent point of the relevant malleolus and the posterior border of the Achilles tendon. In conclusion, this study describes easily identifiable, palpable bony and soft tissue landmarks that could be used to locate the nerves around the ankle.

Variations in the Density and Distribution of Cajal Like Cells Associated With the Pathogenesis of Ureteropelvic Junction Obstruction: A Systematic Review and Meta-Analysis

Introduction: Cajal like cells (CLCs) in the upper urinary tract have an ability to generate coordinated spontaneous action potentials and are hypothesized to help propel urine from renal pelvis into the ureter. The objective of this review was to describe the variations in the density and distribution of CLCs associated with ureteropelvic junction obstruction (UPJO). Materials and Methods: Studies comparing the density and distribution of CLCs in the human upper urinary tract in patients with UPJO and healthy controls were included in this systematic review. We searched online electronic databases; Ovid MEDLINE, Scopus, PubMed and Cochrane reviews for the studies published before October 31, 2020. A meta-analysis was conducted to compare the density of CLCs at the ureteropelvic junction (UPJ) in patients with UPJO and matched controls. Results: We included 20 and seven studies in the qualitative and quantitative synthesis, respectively. In majority (55%) CLCs were located between the muscle layers of the upper urinary tract. The CLC density in the UPJ gradually increased with aging in both healthy subjects and patients with UPJO. The pooled analysis revealed that the density of CLCs at the UPJ was significantly low in patients with UPJO compared to the controls (SMD = -3.00, 95% CI = -3.89 to -2.11, p < 0.01). Conclusions: The reduction in CLC density at the UPJ in patients with UPJO suggests a contribution from CLCs in the pathogenesis of UPJO. Since age positively correlates with CLC density, it is imperative to carefully match age when conducting case control studies comparing the CLC density and distribution. Protocol Registration Number: CRD42020219882.