SLR - August 2017 - Ashton J. Nelsen
Ultrasound-Guided Interventional Procedures in Pain Medicine: A Review of Anatomy, Sonoanatomy and Procedures Part VI: Ankle Joint
Reference: Soneji N and Peng P. Ultrasound-Guided Interventional Procedures in Pain Medicine: A Review of Anatomy, Sonoanatomy and Procedures Part VI: Ankle Joint. Reg Anesth Pain Med 2016; 41: 99–116.
Scientific Literature Review
Reviewed By: Ashton J. Nelsen, DPM
Residency Program: Hennepin County Medical Center
Podiatric Relevance: Diagnostic and therapeutic injections are important procedures in the management of articular and other pathologies. As ultrasound use becomes increasingly common in podiatric practices, it is important to understand sonoanatomy and to familiarize oneself with the efficacy and appropriate techniques to apply this modality, especially as it relates to the diagnosis and treatment of intra-articular pathologies.
Methods: A literature search of the MEDLINE database was performed, looking for articles published between January 1980 and December 2014 related to ultrasound-guided interventional procedures in the ankle. The article begins with a clinical review of ankle, subtalar and syndesmotic joint anatomy. It then goes through sonographic anatomy and shows pertinent related images. There is a thorough discussion of patient positioning for various ultrasound approaches and injection techniques. Depending on the location and technique, an in-plane or out-of-plane technique may be preferred. For ultrasound-guided injections, spread of the injectate is monitored using hydrolocalization.
Results: For the subtalar joint, there are similar extravasation rates between ultrasound-guided, fluoroscopic-guided and anatomically guided injections. Various studies showed higher accuracy rates of ultrasound-guided injections compared to other fluoroscopic or anatomic landmark guided methods. Further results looked at the therapeutic role of different injectates into the foot and ankle. Not many high-level studies exist in this area. This review article found four articles looking at the efficacy of corticosteroid injections in the foot and ankle. One study (Ward, 2008) in adults with osteoarthritis or rheumatoid arthritis had an average improvement in FAOS scores of 40 to 65 percent < six months after injection. Three articles (Remedios, 1997; Cahill, 2007; and Laurell, 2011) looked at the pediatric population with juvenile idiopathic arthritis. Remedios found remission in 66.7 percent > six months after injection. Cahill found an 89 percent improvement in inversion/eversion of the subtalar joint and 44 percent with symptom resolution for an average of 3.25 months. Laurell reported a significant reduction in mean synovial thickness after corticosteroid injections by 87 percent in the tibiotalar joint and 95 percent in the subtalar joint, and 72 percent of patients had an absence of active arthritis at one month follow-up. A table of five randomized controlled trials looking at the efficacy of viscosupplementation in the ankle joint reported one study with positive results compared to normal saline. The remaining four studies showed no difference in outcomes when injecting viscosupplementation or saline. Six prospective cohort studies looking at the efficacy of viscosupplementation in the ankle joint all reported a positive change.
Conclusions: Ultrasound is a useful modality for identifying anatomic structures of the foot and ankle. It improves the accuracy rate of intra-articular injections. Corticosteroid injections are beneficial in the treatment of arthritis, while viscosupplementation use remains controversial. This article is an excellent resource for a review of clinical and sonographic anatomy of the ankle joint, as well as ultrasound-guided injection techniques in this area of the body.