Ankle distraction arthroplasty (ADA): A brief review and technical pearls

Abstract

Ankle distraction arthroplasty (ADA) is a procedure based on the concept that mechanical unloading of an arthritic joint will initiate a healing response in the subchondral bone and articular cartilage. ADA utilizes the patient's own healing response, preserves joint motion, and is a great option for patients with osteoarthritis who are not ready for prosthetic arthroplasty or fusion. The procedure is well described and technically simple and adjunctive biologic therapies are exciting for joint regeneration. Complications are minor, and more serious adverse events are avoidable. Supramalleolar osteotomy pairs well with ankle distraction but requires some analysis and planning.

Keywords: Ankle arthritis; Ankle distraction; Arthroplasty; Deformity; Supramalleolar osteotomy.

Fig. 1

This AP radiograph depicts a 2-ring external fixation construct used for ankle distraction arthroplasty. A gap of 5 mm is seen in the ankle joint.

Fig. 2

The universal hinges are seen lined up with the natural hinge of the ankle joint on this intra operative fluoroscopic image (a). A typical hinged external fixator is seen (b).

Fig. 3

This intra operative image shows drilling of the subchondral bone with a K-wire to stimulate an inflammatory response.

Fig. 4

Bone marrow aspirate concentrate harvested from the patient's iliac crest is being injected into the arthritic ankle joint under fluoroscopic guidance (a). The bone marrow can be injected into the subchondral bone via metaphyseal drill holes (b).

Fig. 5

The pre operative AP (a) and Lateral (b) radiographs show an osteoarthritic ankle joint one year following a pilon fracture in a young female adult. The patient underwent ankle distraction arthroplasty surgery and three months of distraction treatment (c). Radiographs taken one year later (d,e) show improved joint space which was accompanied by a dramatic reduction in pain with improvement in function. A one year post surgery MRI (f) shows fill of the tibiotalar space with reparative cartilage.

Fig. 6

The pre operative AP (a), Mortise (b) and Lateral (c) radiographs show an osteoarthritic ankle joint in a middled aged male with valgus deformity stemming from both the joint and the distal tibia. An external fixator with automatic struts was used to correct the deformity gradually through an SMO while also applying gradual joint distraction (d). The post correction images show a well aligned osteotomy and 6 mm of joint space (e,f). Final weight bearing images taken nine months post surgery show maintenance of the alignment correction and increased joint space (g,h,i). Clinically the patient is reaching high levels of activity including plyometrics without pain.