title: Viscosupplementation with intra-articular hyaluronic acid for hip disorders. A systematic review and meta-analysis.
abstract: BACKGROUND
  Hip joint diseases are common in adult population and their prevalence increases with age. Osteoarthritis, rheumatoid arthritis and femoroacetabular impingement are the most common chronic diseases in the hip joint. Viscosupplementation with exogenous hyaluronic acid (HA) is one of the most widely used conservative treatment aiming to improve synovial fluid properties and to decrease pain. There is no global consensus on the type of HA, method of injection and frequency, or on its efficacy in hip joint.
  
  
  METHODS
  We selected published data in English in the PubMed and Google Scholar electronic databases up to March 2016 about hyaluronic acid injections in hip disorders.
  
  
  RESULTS
  26 articles were included following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
  
  
  CONCLUSIONS
  There is a lack of standardization of HA injections for hip conditions. Our results suggest that this is the best conservative therapy before surgery and it can act on pain relief and function however there is no evidence to prove its ability to modify the morphological structure of the pathological hip and the natural history of the disease. There are few data about the use of HA in other hip disorders rather than osteoarthritis. The most relevant evidence seems to show the utility of HA injections in improving synovial inflammation, but only a few studies have been conducted.
  
  
  METHODS
  I.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Rome "Tor Vergata", Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Piccirilli
authors.affiliation: Department of Orthopaedics and Traumatology, University of Rome "Tor Vergata", Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Oliva
authors.affiliation: Department of Physical and Rehabilitation Medicine, School of Medicine, University of Rome "Tor Vergata", Italy.
authors.forename: Mihaela Aconstantinesei
authors.initials: MA
authors.lastname: Murè
authors.affiliation: Department of Physical and Rehabilitation Medicine, School of Medicine, University of Rome "Tor Vergata", Italy; Physical medicine, Rheumatology and rehabilitation department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Asmaa
authors.initials: A
authors.lastname: Mahmoud
authors.affiliation: Department of Physical and Rehabilitation Medicine, School of Medicine, University of Rome "Tor Vergata", Italy.
authors.forename: Calogero
authors.initials: C
authors.lastname: Foti
authors.affiliation: Department of Orthopaedics and Traumatology, University of Rome "Tor Vergata", Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Tarantino
authors.affiliation: Head of Department of Orthopaedics and Traumatology, Azienda Ospedaliera San Giovanni di Dio e Ruggi d'Aragona, University of Salerno, Italy; Queen Mary University of London, Barts and the London School of Medicine and Dentistry, Centre for Sports and Exercise Medicine, Mile End Hospital, London, UK.
authors.forename: Nicola
authors.initials: N
authors.lastname: Maffulli
keywords: hip diseases; hip disorders; hip injections; hyaluronic acid