Dorsal minimally invasive plate osteosynthesis of the distal tibia with regard to adjacent anatomical characteristics.

INTRODUCTION: The aim of this study was to perform MIPO of the distal tibia from a dorsomedial and dorsolateral approach and to evaluate their feasibility and risk of injury to adjacent anatomical structures. MATERIAL & METHODS: A total of 18 extremities from 9 adult human cadavers was included in the study. In each cadaver, one lower leg underwent application of a 12-hole 3.5 LCP metaphyseal plate from the medial and the further one from the lateral approach. For the medial approach, a 4 cm skin incision was performed at the tibial border of the Achilles tendon, starting from 1 cm proximal to its insertion point at the calcaneal tuberosity. Entrance was gained between the medial border of the flexor hallucis longus tendon and the medial neurovascular bundle. Regarding the lateral approach, the skin was incised over a length of about 4 cm at the lateral border of the Achilles tendon, approximately 1 cm proximal to its insertion point. Entrance was gained between the Achilles tendon and the peroneus brevis muscle. The plates were inserted in direct bone contact in a proximal direction and the proximal and distal ends were fixed. During dissection, the proximal and distal holes beneath the crossing points of the neurovascular bundle and the plate were noted. The distal and proximal intersection points of the neurovascular bundle and the plate were measured with reference to the distal border of the plate. RESULTS: Concerning the medial approach, the neurovascular bundle was on median located between the 6th and 11th plate holes starting from distal. The bundle intersected the plate distally at a mean height of 65.8 mm and proximally at 156.8 mm on average. For the lateral approach, the neurovascular bundle was situated between the 6th and the 12th plate hole from distal. It crossed the plate distally at a mean of 61.0 mm and proximal at a mean height of 153.9 mm. In none of the cases, lacerations of the neurovascular bundle were observed. CONCLUSION: In conclusion, MIPO from the dorsomedial and dorsolateral approach are both safe procedures as indicated by our study.

Carpal tunnel release: Safe and simple identification of the flexor retinaculum based on superficial anatomical landmarks.

The aim of our study was to project the borders of the flexor retinaculum (FR) onto superficial landmarks since its insufficient splitting is the most common reason for persistence of symptoms after carpal tunnel release. In 60 hands the radial and ulnar styloid processes were linked by a horizontal line and a longitudinal line was laid through the ring finger's radial side. These were intersected resulting in the reference point "A" on the forearm. As the second basing point "B", the radial margin of the ring finger at the palmar digital crease was chosen. Measurement of the FR was carried out with regard to the reference points. The proximal margin of the FR was located at 4% of the reference line A-B starting from point A and extended up to 52% of this total length. Results indicate that splitting alongside the proximal half of line A-B divides the FR completely. Clin. Anat. 30:512-516, 2017. © 2017 Wiley Periodicals, Inc.

The risk of neurovascular injury in minimally invasive plate osteosynthesis (MIPO) when using a distal tibia anterolateral plate: a cadaver study.

PURPOSE OF THE STUDY: Percutaneous plating of the distal tibia via a limited incision is an accepted technique of osteosynthesis for extra-articular and simple intra-articular distal tibia fractures. The aim of this study was to analyze structures that are at risk during this approach. MATERIAL AND METHODS: Thirteen unpaired adult lower limbs were used for this study. Thirteen, 15-hole LCP anterolateral distal tibial plates were percutaneously inserted according to the recommended technique. Dissection was performed to examine the relation of the superficial and deep peroneal nerves and anterior tibial artery relative to the plate. RESULTS: The superficial peroneal nerve was found to cross the vertical limb of the LCP plate at a mean distance of 63 mm (screw hole five) but with a wide range of 21 to 105 mm. The neurovascular bundle (deep peroneal nerve and anterior tibial artery) crossed the plate at a mean of 76 mm (screw hole six) but also with a wide range of 38 to 138 mm. The zone of danger of the neurovascular structures ranges from 21 to 138 mm from the tibial plafond. In one specimen, a significant branch of the deep peroneal nerve was found to be entrapped under the plate. CONCLUSION: Caution is advised when using anterolateral minimally invasive technique for plate insertion and screw placement in the distal tibia due to great variability in the neurovascular structures that course distally in the lower leg and cross the ankle.