A small anterior tibial spur in a "footballer's ankle"
Anterior synovitis on a contrast-enhanced MR scan
If there is clinical evidence of an inflammatory arthropathy this should be evaluated with the appropriate blood tests: FBC, ESR and rheumatoid factor tests are normally sufficient; in a possible spondyloarthropathy the HLA B-27 may be added.
Plain films will show spurs and loss of joint space.
MR can identify synovitis and impingement, especially with contrast or MR arthrography. Schaffler (2003) found that MR had a sensitivity of 89% and a specificity of 100% for syndesmotic impingement tissue. Huh (2003) found sensitivity of 91% and specificity of 64% for synovitis, and sensitivity of 76% and specificity of 97% for impingement. Haller (2006) found better agreement between MR and arthroscopy in the lateral ligaments and anterior gutter than for the inferior tibiofibular ligaments and medial gutter. They also identified extra-articular causes of anterior ankle pain (mainly anterior tenosynovitis) in 17% of their patients.
However, impingement is largely a clinical diagnosis. In our practice imaging is mainly used for patients with intra-articular or atypical pain.