title: Symptomatic and chondroprotective treatment with collagen derivatives in osteoarthritis: a systematic review.
abstract: OBJECTIVE
  Osteoarthritis (OA) is one of the most prevalent musculoskeletal diseases. Collagen derivatives are candidates for disease-modifying OA drugs. This group of derivatives can be divided into undenatured collagen (UC), gelatine and collagen hydrolysate (CH). Collagen derivatives are marketed as having direct chondroprotective action and reducing complaints of OA. This review summarizes the evidence for the effectiveness of symptomatic and chondroprotective treatment with collagen derivatives in patients with OA.
  
  
  METHODS
  Eligible randomised controlled trials (RCTs) and quasi-RCTs were identified by searching PubMed, Embase and the Cochrane Central Register of Controlled Trials until November 2011. Methodological quality was assessed using methods of the Cochrane Back Review Group.
  
  
  RESULTS
  Eight studies were identified: six on CH, two on gelatine, and one on UC. The pooled mean difference based on three studies for pain reduction measured with the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index comparing CH with placebo was -0.49 (95% CI -1.10-0.12). However, some studies report significant between-group differences in pain when measured with a visual analogical scale (VAS) or other instruments, or when CH is compared with glucosamine sulphate. For disability no significant between-group mean differences were found when comparing CH with placebo. Gelatine compared with placebo and with alternative therapies was superior for the outcome pain. UC compared with glucosamine+chondroitin showed no significant between-group differences for pain and disability. The most reported adverse events of collagen derivatives were mild to moderate gastro-intestinal complaints. The overall quality of evidence was moderate to very low.
  
  
  CONCLUSIONS
  There is insufficient evidence to recommend the generalized use of CHs in daily practice for the treatment of patients with OA. More independent high-quality studies are needed to confirm the therapeutic effects of collagen derivatives on OA complaints.
authors.affiliation: Department of General Practice, Erasmus MC, University Medical Center Rotterdam, The Netherlands. j.p.j.vanvijven@erasmusmc.nl
authors.forename: J P J
authors.initials: JP
authors.lastname: Van Vijven
authors.forename: P A J
authors.initials: PA
authors.lastname: Luijsterburg
authors.forename: A P
authors.initials: AP
authors.lastname: Verhagen
authors.forename: G J V M
authors.initials: GJ
authors.lastname: van Osch
authors.forename: M
authors.initials: M
authors.lastname: Kloppenburg
authors.forename: S M A
authors.initials: SM
authors.lastname: Bierma-Zeinstra
mesh_terms: D002807:Chondroitin / Q000627:therapeutic use; D003094:Collagen / Q000627:therapeutic use*; D005260:Female; D005780:Gelatin / Q000627:therapeutic use*; D005944:Glucosamine / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000188:drug therapy; D020370:Osteoarthritis, Knee / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy; D010147:Pain Measurement / Q000379:methods; D011492:Protein Hydrolysates / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
chemical_list: D011492:Protein Hydrolysates; D005780:Gelatin; D002807:Chondroitin; D003094:Collagen; D005944:Glucosamine