title: Increased cartilage volume after injection of hyaluronic acid in osteoarthritis knee patients who underwent high tibial osteotomy.
abstract: OBJECTIVE
  High tibial osteotomy (HTO) is a surgical procedure used to correct abnormal mechanical loading of the knee joint; additionally, intra-articular hyaluronic acid injections have been shown to restore the viscoelastic properties of synovial fluid and balance abnormal biochemical processes. It was hypothesized that combining HTO with intra-articular hyaluronic acid injections would have benefit to improve the cartilage volume of knee joints.
  
  
  METHODS
  Forty patients with medial compartment knee osteoarthritis (OA) were randomly placed into 1 of 2 groups. The study group (n = 20) received 2 cycles (at 6-month intervals) of 5 weekly intra-articular hyaluronic acid injections after HTO operation. The control group (n = 20) did not receive any intra-articular injections after HTO surgery. Cartilage volume (primary outcome) was assessed by magnetic resonance imaging (MRI) pre-operatively and 1 year post-operatively. Treatment efficacy (secondary outcomes) was evaluated with the Western Ontario and McMaster Universities OA Index (WOMAC) and by the comparison of the total rescue medication (paracetamol/diclofenac) used (weeks 6, 12, 24, 48).
  
  
  RESULTS
  MRI studies showed a significant increase in total cartilage volume (p = 0.033), lateral femoral cartilage volume (p = 0.044) and lateral tibial cartilage volume (p = 0.027) in the study group. Cartilage volume loss was detected at the lateral tibial plateau in the control group. There were significant improvements after surgery in both groups for all subscales of WOMAC scores (p < 0.001) compared to the baseline. However, no difference was found between the two groups. The study group had significantly lower amounts of diclofenac consumption (p = 0.017).
  
  
  CONCLUSIONS
  Based on the findings of the present study, intra-articular hyaluronic acid injections may be beneficial for increasing total cartilage volume and preventing the loss of lateral tibiofemoral joint cartilage after HTO.
  
  
  METHODS
  Therapeutic study, Level I.
authors.affiliation: Department of Orthopaedics Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Siriraj Hospital 2 Prannok Road Bangkoknoi, Bangkok, 10700, Thailand, sikcr@mahidol.ac.th.
authors.forename: Keerati
authors.initials: K
authors.lastname: Chareancholvanich
authors.forename: Chaturong
authors.initials: C
authors.lastname: Pornrattanamaneewong
authors.forename: Rapeepat
authors.initials: R
authors.lastname: Narkbunnam
mesh_terms: D002358:Cartilage, Articular / Q000187:drug effects / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007270:Injections, Intra-Articular; D007719:Knee Joint / Q000187:drug effects / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000601:surgery*; D010027:Osteotomy; D055675:Viscosupplements / Q000008:administration & dosage*
chemical_list: D055675:Viscosupplements; D006820:Hyaluronic Acid