Ultrasound-guided injection of the ankle joint: cadaveric investigation of the anterolateral approach.

OBJECTIVE

Injection of the tibiotalar (TT) joint is commonly performed in clinical practice under ultrasound (US) guidance using an anteromedial approach. However, in some patients, this approach may be technically challenging due to post-traumatic and/or degenerative bony changes. Therefore, the aim of this cadaveric investigation was to demonstrate the feasibility of the ultrasound-guided (USG) injection of the ankle joint via the anterolateral sulcus (ALS) by confirming the dye placement/distribution inside the articular space. Likewise, the safety of the procedure has also been evaluated by measuring the distance between the needle and the intermediate dorsal cutaneous nerve of the foot.

DESIGN

A descriptive laboratory study with eight embalmed cadaveric ankles using the Fix for Life (F4L) method was performed at the setting of an academic institution. The interventional technique and the related anatomical findings were illustrated. During the injection, the needle was advanced into the TT joint through the ALS under US guidance, i.e., in-plane anterior-to-posterior approach. With the objective to confirm its correct placement, the needle was kept in situ and-to demonstrate the location of the dye inside the articular space-all eight ankles were injected with 3 mL of green color dye. Thereafter, a layer-by-layer anatomical dissection was performed on all four cadavers.

RESULTS

The position of the needle's tip within the ALS was confirmed in all specimens. Accurate placement of the dye inside the articular space of the ankle was confirmed in seven of the eight cadaveric ankles, with 87.5% of accuracy. Herewith, unintentional spilling of the dye within the superficial soft tissues was reported in two of the eight ankles (25.0%). The mean distance between the needle and the intermediate dorsal cutaneous nerve of the foot, measured in all eight procedures, was 3 cm.

CONCLUSION

USG injection of the ALS using the in-plane, anterior-to-posterior approach can accurately place the injectate inside the articular space.

CLINICAL RELEVANCE

This cadaveric investigation described the accuracy and potential pitfalls of USG injection of the ankle via the anterolateral approach which represents an alternative technique in patients with reduced accessibility of the anteromedial recess due to degenerative and/or post-traumatic bony changes.