Comparison of four posterior approaches of the ankle: A cadaveric study

Abstract

Objectives: The purpose of this study is to provide a detailed comparison of 4 posterior approaches of the ankle: the posteromedial, modified posteromedial (mPM), Achilles tendon-splitting (TS), and posterolateral approaches. Methods: Cadaveric dissections were performed to assess the influence of the medial and lateral retraction forces on the neuro-vascular bundle with suspension scales and to measure the medial and lateral exposed areas of the posterior tibia and talus. Data was acquired with the ankle in neutral position and in plantar flexion. Results: Both the mPM and TS approaches provided excellent visualization of the posterior tibia with the ankle in plantar flexion (16.6 cm 2 and 16.2 cm 2 , respectively). The medial aspect of the posterior tibia, however, was significantly better exposed in the mPM approach than in the TS approach with the ankle in neutral position (8.9 cm 2 vs 6.5 cm 2 ). The lower value for medial retraction force in the mPM approach (1.9 N in neutral position and 0.9 N in plantar flexion) indicated a lower risk of injury to the neuro-vascular bundle (the tibial nerve and the posterior tibial artery). The posterior talus, however, is best visualized through the TS approach with the ankle in neutral position (4.5 cm 2 ). Conclusions: The current study demonstrated the usefulness of the mPM approach. When internal fixation of the fibula is unnecessary, the mPM approach is preferable, considering the potential damage to the Achilles tendon associated with the TS approach.

Ultrasound evaluation of a new surface reference line to describe sural nerve location and safe zones to consider in posterior leg approaches

“…Proximal zones and points may be useful in revision surgery or chronic Achilles tendon rupture surgery [ 16 , 31 , 41 , 44 ] or in some Achilles tendon lengthening techniques [ 7 , 10 , 19 , 41 ]. The central zones may be useful in acute Achilles pathology surgeries [ 12 , 22 , 35 , 47 ] and distal zones in arthroscopic surgeries [ 2 , 23 , 34 ] or ankle fractures [ 18 , 29 , 33 ]. This new reference line can be easily reproduced intraoperatively (using suture or electric scalpel wire) by the surgeon when planning the approach.…”

“…Some posterior leg approaches have a high risk of SN injury [ 30 , 47 ]. These approaches are often used in acute [ 12 , 35 , 47 ] or chronic [ 16 , 44 ] Achilles pathology, ankle arthroscopy [ 2 , 23 , 34 ] or ankle fractures [ 18 , 29 , 33 ]. Several authors have attempted to predict the SN location with distance units from the Achilles tendon [ 6 , 10 , 14 , 20 , 46 ] or the lateral malleolus [ 9 , 14 , 15 , 18 , 24 , 30 ], but these units can be altered according to height [ 15 , 20 ], leg length [ 6 ] or body mass index (BMI) [ 15 ].…”

Direct fixation of posterior malleolus fractures-posterolateral or posteromedial approach?

“…Authors argued that it is needed, because there are no ligamentous insertions that can aid fracture reduction by ligamentotaxis 15 . In a cadaver study, Mitsuzawa et al, compared posteromedial, modified posteromedial (mPM), Achilles tendon-splitting (TS), and posterolateral approaches to the PM 16 .The authors found that the latter, directly endangers the sural nerve and branches of the peroneal artery and does not allow sufficient visualisation of the medial side.The modified posteromedial approach originally described by Assal M 17 , was developed in the interval between the medial neuromuscular bundle and the Achilles tendon. It was found it to be safest and to offer best visualisation, both to the lateral and medial side of the posterior pilon.…”

Avaliação clínica e radiográfica pós-operatória da via posterolateral do tornozelo

“…Para estas fraturas as abordagens posteriores, como a via posterolateral ou posteromedial, tornaramse mais utilizadas, favorecendo a exposição e a fixação interna. A visibilização do tálus, por exemplo, é importante nas abordagens posteriores, pois permite avaliar um possível dano articular 5 .…”