May the Symptomatic Subtalar Joint Be Conservatively Treated With Intra-Articular Hyaluronic Acid Injections After a Calcaneus Fracture?

Background: Subtalar pain following intra-articular calcaneus fractures may be associated with disability, pain, and a negative impact on the quality of life. Salvage procedures as subtalar fusion are associated with further consequences as stiffness, altered ankle biomechanics, and adjacent articular overloading with degenerative changes. The objective of the present study is to evaluate the short-term effects of viscosupplementation with intra-articular hyaluronic acid (HA) on function and pain, in patients with painful subtalar joint after calcaneus fracture.

Methods: We searched for patients who underwent osteosynthesis of intra-articular calcaneus fracture between January 2011 and July 2015 and were diagnosed during the follow-up with pain and subtalar osteoarthritis. Between January and December of 2018, 13 patients (50 ± 10 years) accepted to participate in this study and received intra-articular HA injections. Three consecutive doses of 20 mg of HA were administered within a week interval, through anterolateral injections into the subtalar joint. We prospectively evaluated the function using the ankle/hindfoot American Orthopaedic Foot & Ankle Society score (AOFAS) and level of pain using the visual analog scale (VAS) before the intervention and 4, 12, and 24 weeks after the first injection.

Results: Hindfoot function improved with an increase of AOFAS from 55 ± 19 before the intervention to 88 ± 20 at the 24th week (P = .001). Similarly, we observed relief of pain during the 24 weeks following intra-articular hyaluronic acid injection, with a decrease in VAS from 8.3 ± 1.3 before treatment to 2.2 ± 3.0 at the 24th week (P = .001).

Conclusion: For patients experiencing pain and dysfunction with subtalar osteoarthritis after intra-articular calcaneus fracture, viscosupplementation with intra-articular HA may be associated with improvement in function and pain in the short term. Furthermore, patients with higher grades of osteoarthritis may have limited benefit in pain relief and function improvement.

Level of evidence: IV, Case series.