Results of Treatment of Posterior Ankle Impingement Syndrome and Flexor Hallucis Longus Tendinopathy in Dancers: A Systematic Review.

Dancing on pointe and relevé requires extreme plantar flexion of the talo-crural joint. Hence, these positions may lead to posterior ankle impingement syndrome (PAIS). PAIS often coincides with flexor hallucis longus tendinopathy (FHL tendinopathy, or "dancers' tendinitis"). Both injuries can appear in isolation as well. The goal of this review is to evaluate the results and the available levels of evidence of conservative and operative treatment (both open and endoscopic) of PAIS and FHL tendinopathy in dancers. It also offers an insight into the history of dance medical publications on this subject. In October 2016, a systematic search of PubMed, Embase, Cochrane, CINAHL, Web of Science, and (in French) ScienceDirect databases was undertaken. Five hundred and seventy-six publications were found, of which a total of 27 reported the results of operative treatment in 376 ankles (344 open, 32 endoscopic) in 324 dancers. The outcome was good to excellent in most cases (89%). The mean period of return to dance for all surgeries combined (PAIS and FHL tendinopathy, open and endo) was 11 weeks (range: 4 to 36 weeks), and for isolated FHL tendinopathy 16 weeks (range: 8 to 36 weeks). Only six publications reported the results of conservative treatment in 33 ankles (13 PAIS, 20 FHL tendinopathy) of 28 dancers, which does not allow for any evidence-based recommendations. Most studies failed to include dance-specific baseline characteristics, like dance style and level of participation. We concluded that only retrospective studies with levels of evidence four and five show that operative treatment for PAIS and FHL tendinopathy is successful with few complications. Since isolated PAIS, PAIS combined with FHL tendinopathy, and isolated FHL injuries appear to be different pathological entities, more research taking into account demography, dance type, and level of participation is needed to find out in which cases early operative management should be considered or avoided. The same applies to defining the place of endoscopic surgery in dancers and being able better to predict which pathology is likely to produce worse outcomes or delay the return to dance. Future research should have a prospective design, including dance-specific outcome scores both preand post-treatment. Furthermore, preferably a prospective randomized controlled design should be used to compare different conservative and operative treatment options.