How to perform a medial ankle approach
Source
Surgeon:
Lasse Rämö (orthopedic surgeon)
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Summary
Focus: Safe and adequate access to the medial malleolar fracture site.
Key elements: Incision planning around the medial malleolus, protection of the saphenous nerve and great saphenous vein, fracture site exposure, fixation considerations, wound closure, pitfalls, complications, and aftercare.
Indications and Clinical Context
General
Surgeon: Lasse Rämö (orthopedic surgeon)
Medical experts: Lasse Rämö (orthopedic surgeon), Thomas Schlenzka (orthopedic surgeon), Mikael Åkerback (orthopedic surgeon)
Name of operation: Medial ankle approach
Goal of operation
To ensure safe and adequate access to the fracture site, as well as to restore the anatomy of the ankle mortise and the function of the ankle joint by fixating the fracture.
Problem
A fracture leading to a deformed or unstable ankle joint.
Diagnosis
Fracture of the medial malleolus (ICD-10 S82.5)
Short Pathophysiological Description
The malleoli of tibia and fibula hold the talus stable against the distal surface of tibia, at the talocrural joint. These three structures - the malleoli and the distal articular surface of tibia (=the tibial plafond) - form the ankle mortise. Ankle syndesmosis is a ligament complex binding distal tibia and fibula together, ensuring the stability of the ankle mortise, crucial for its function. Some ankle fractures deform the ankle mortise, or destabilize it, compromising joint functionality. In addition, fracture displacements at the joint surfaces may lead to post-traumatic arthritis. These types of fractures often require surgical treatment.
Presented on our platform are three approaches, that should provide adequate exposure for the majority of common malleolar fractures (either isolated medial/lateral, bimalleolar or trimalleolar). The “third” malleolus stands for the posterior aspect of the tibial plafond, referred to as the posterior malleolus.
Generally, isolated fractures of the lateral malleolus and distal fibula can be approached via the lateral approach, fractures of the posterior malleolus via the posterolateral approach (that also allows exposure of distal fibula) and fractures of the medial malleolus via the medial approach.
Key anatomical structures
Tibia
Talus
Saphenous nerve
Great saphenous veins
Step-by-Step Technique
Patient positioning, anesthesia and preparation
Patient is supine, with the leg in neutral position, adequately exposing the medial malleolus.
Both spinal and general anesthesia are applicable.
Landmarks
Visualize and palpate the landmarks for your incision. Locate the medial malleolus and the level of the talocrural joint. When planning the incision, note that the tibialis posterior tendon runs posterior to the medial malleolus, and saphenous nerve and the great saphenous vein run anteromedial of the malleolus.
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Skin incision
Begin the incision a few centimeters distal and slightly anterior to the anterior portion of the medial malleolus (the anterior colliculus).
Continue proximally, curving the incision so that it runs in parallel with distal tibia.
The proximal part of the incision should run in the midline of tibia.
Advance through subcutis
Carefully advance through the subcutaneous fat. Look out for the saphenous nerve. Also, the great saphenous vein running with the nerve should be protected/left intact.
Be careful not to damage the nerves and vessels when using retractors. Spreading or stretching the wound in excess will likely result in iatrogenic injury.
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Expose the fracture site
Remove any debris interfering with fracture reduction. Here you will likely find a periosteal flap interposed between the bone fragments.
When necessary, strip the periosteum, but keep this to a minimum to preserve as much of the blood supply as possible.
In order to inspect the joint and remove any intra-articular debris, you may need to make a small anteromedial arthrotomy. Sometimes the joint capsule is already torn due to the injury.
This is the end of the approach section. In fracture surgery, you would now reduce and fixate the fracture.
Reduce and fix the fracture
When adequately reduced, you can temporarily fix the fracture with reduction forceps. Make sure to inspect the articular surface (through the arthrotomy or torn joint capsule) before definitive fixation.
For most fractures, screw fixation with two partially threaded cancellous bone screws provides sufficient fixation.
Wound Closure
If the joint capsule can be closed, it can be sutured using an absorbable suture (e.g. 0 Vicryl). Be careful not to take a suture bite of the saphenous nerve or the great saphenous vein, which are running anterior to the operation site.
The subcutis can be closed e.g. with continuous sutures using absorbable 2-0 sutures.
Skin can be closed with mattress sutures (or surgical staples).
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Piftalls and Complications
Pitfalls
Incorrect site of incision
An incision made too anterior may cause injury to the saphenous nerve and the great saphenous vein, which run anteromedially to the medial malleolus. The posterior tibial tendon is located posteriorly to the malleolus and is at risk if the incision is made too posteriorly. It is advisable to make the incision at the midline of the medial malleolus, with an anterior curvature distally. The aim is to expose the medial malleolus and gain access anterior to it, enabling evaluation of the fracture reduction in reference to the joint surface in direct visual control.
Careless tissue handling
Undue skin tension from a retractor may cause injury to the adjacent structures, the saphenous nerve included.
Complications
Injury to the saphenous nerve
The saphenous nerve runs anteromedially to the medial malleolus and its course should be noted when making the skin incision. Likewise, when closing the joint capsule and subcutis, caution should be exercised not to include the nerve in the suture bites. Injury to the saphenous nerve may result in neuralgia or paraesthesia in the medial side of the foot.
Injury to the posterior tibial tendon
The posterior tibial tendon runs along the posterior edge of the medial malleolus. Its course should be noted during the skin incision and other stages of the operation. If injured, the tendon should be sutured, and the patient immobilized for recovery. Injury to the posterior tibial tendon results in inversion/plantar flexion weakness of the foot and flattening of the plantar arch.
Injury to the great saphenous vein
The great saphenous vein runs along with the saphenous nerve in the anteromedial area of the medial malleolus. However, if injured, ligation of the vein can be performed without any problem.
Infection
Infection is a potential complication of surgery that can result in significant morbidity and healthcare resource utilization. Infections associated with implanted surgical devices are particularly difficult to deal with because they can require prolonged antibiotic treatment and repeated surgical procedures. Prevention of infection is an imperative part of any surgical procedure.
Aftercare
General guidelines:
Casting, weight-bearing and other rehabilitation guidelines depend largely on the type of fracture treated.
FAQ
What is the goal of the medial ankle approach?
The goal is to ensure safe and adequate access to the fracture site, and to restore the anatomy of the ankle mortise and the function of the ankle joint by fixating the fracture.
Which fracture is listed for this approach?
The listed diagnosis is fracture of the medial malleolus.
What structures should be considered when planning the incision?
When planning the incision, note that the tibialis posterior tendon runs posterior to the medial malleolus, and the saphenous nerve and great saphenous vein run anteromedial of the malleolus.
Where should the skin incision begin?
The incision begins a few centimeters distal and slightly anterior to the anterior portion of the medial malleolus, the anterior colliculus.
What should be protected when advancing through the subcutis?
The saphenous nerve should be looked out for, and the great saphenous vein running with the nerve should be protected and left intact.
What may be needed to inspect the joint and remove intra-articular debris?
A small anteromedial arthrotomy may be needed. Sometimes the joint capsule is already torn due to the injury.
What fixation is described for most fractures?
For most fractures, screw fixation with two partially threaded cancellous bone screws provides sufficient fixation.
What does aftercare depend on?
Casting, weight-bearing, and other rehabilitation guidelines depend largely on the type of fracture treated.
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