A new anterior inferior coronal patellar plica

Purpose: To date, four synovial plicae are classically described in the knee. We report a previously undescribed new inferior patellar plica, named "bib-like plica" (BLP, referring to its morphology) related to specific symptoms of atypical recurrent anterior knee pain in the presence of a locked or pseudo-locked knee. We describe this anatomical structure, and assess its clinical relevance in daily practice in terms of clinical pattern and long-term follow-up outcome after arthroscopic excision.Methods: We retrospectively reviewed prospectively collected data on 1033 arthroscopic procedures, selecting patients in whom a knee arthroscopy was indicated following recurrent painful episodes of locking or pseudo-locking not explained by traditional imaging or helped by conservative treatment. Visual Analog Scale (VAS), Lysholm knee score, a physical exam and a satisfaction interview were used to evaluate the clinical status at the latest follow-up.Results: We report 12 patients (8 males, 4 females; mean age 34.2 years) in whom a BLP had been identified at arthroscopy. At a mean follow-up of 13.4 years from its excision, the mean VAS and Lysholm knee score were 9.8 and 100 respectively. In all instances, selective removal of the BLP restored a complete painless functional range of motion documented within 2 months, and confirmed at the latest follow-up. No patient reported locking recurrence or pain, or underwent further surgery, and all were satisfied.Conclusions: The BLP, detected in about 1% of knee arthroscopies in our setting, is strongly associated with a recurrent painful locking knee. Arthroscopic removal produces resolution of symptoms. (C) 2017 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.