A Comprehensive Review of Radiohumeral Synovial Plicae for a Correct Clinical Interpretation in Intractable Lateral Epicondylitis.

Radiohumeral synovial plicae (RHSP) have been studied by different authors in different ways; in spite of this, the evidence is poor and the results are controversial and inconclusive even when it comes to referring to this elbow structure. The aim of this article is to review the embryologic development, anatomy and histology, pathophysiologic features, clinical manifestations, physical examination, imaging findings, and treatment of radiohumeral synovial plicae, for their correct clinical interpretation in patients with intractable lateral epicondylitis. Radiohumeral synovial plicae syndrome (RHSPS) can cause intractable lateral epicondylitis and can be easily confused with other clinical conditions affecting the elbow. Many clinicians are not familiar with radiohumeral synovial plica syndrome since there are not many studies about it and previous reports do not seem to reach a consensus. Although its role in elbow injuries and epicondylitis is accepted and its surgical treatment is effective, there is no clear consensus about clinically relevant aspects. RHSP are remnants of normal embryo development of the articular synovial membrane with different anatomical locations, size and shape. Traumatism or overuse can turn RHSP into symptomatic structures at any age and can be compressed between the radial and humeral heads during movement. This compression can cause pain and other symptoms such as snapping, catching, mobility restriction, pitching, clicking, locking, blockage, popping and swelling. Radiohumeral synovial plica syndrome (RHSPS) may be an isolated condition or it can be associated with other elbow abnormalities. The findings on physical examination and imaging diagnosis are multiple and variable. Nowadays, RHSPS are quite unknown and previous reports do not seem to agree, leading to misdiagnoses as epicondylitis and making this structure the main cause of some cases of "intractable lateral epicondylitis". The outcomes of surgical treatments are quite promising although more, higher quality research is needed. Taking this into account, this review is meant to be a starting point for new anatomical and clinical studies.