Knee joint distraction in regular care for treatment of knee osteoarthritis: A comparison with clinical trial data

PLoS One. 2020 Jan 22;15(1):e0227975. doi: 10.1371/journal.pone.0227975. eCollection 2020.


Objectives: Knee joint distraction (KJD) has been evaluated as a joint-preserving treatment to postpone total knee arthroplasty in knee osteoarthritis patients in three clinical trials. Since 2014 the treatment is used in regular care in some hospitals, which might lead to a deviation from the original indication and decreased treatment outcome. In this study, baseline characteristics, complications and clinical benefit are compared between patients treated in regular care and in clinical trials.

Methods: In our hospital, 84 patients were treated in regular care for 6 weeks with KJD. Surgical details, complications, and range of motion were assessed from patient hospital charts. Patient-reported outcome measures were evaluated in regular care before and one year after treatment. Trial patients (n = 62) were treated and followed as described in literature.

Results: Patient characteristics were not significantly different between groups, except for distraction duration (regular care 45.3±4.3; clinical trials 48.1±8.1 days; p = 0.019). Pin tract infections were the most occurring complication (70% regular care; 66% clinical trials), but there was no significant difference in treatment complications between groups (p>0.1). The range of motion was recovered within a year after treatment for both groups. WOMAC questionnaires showed statistically and clinically significant improvement for both groups (both p<0.001 and >15 points in all subscales) and no significant differences between groups (all differences p>0.05). After one year, 70% of patients were responders (regular care 61%, trial 75%; p = 0.120). Neither regular care compared to clinical trial, nor any other characteristic could predict clinical response.

Conclusions: KJD as joint-preserving treatment in clinical practice, to postpone arthroplasty for end-stage knee osteoarthritis patient below the age of 65, results in an outcome similar to that thus far demonstrated in clinical trials. Longer follow-up in regular care is needed to test whether also long-term results remain beneficial and comparable to trial data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Bacterial Agents / administration & dosage
  • Arthroplasty, Replacement, Knee
  • Cartilage, Articular / diagnostic imaging
  • Cartilage, Articular / physiopathology
  • Cartilage, Articular / surgery
  • Clinical Trials as Topic / standards
  • External Fixators
  • Female
  • Humans
  • Knee Joint / diagnostic imaging
  • Knee Joint / physiopathology
  • Knee Joint / surgery*
  • Male
  • Middle Aged
  • Orthopedic Procedures / standards
  • Osteoarthritis, Knee / diagnostic imaging
  • Osteoarthritis, Knee / epidemiology
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / surgery*
  • Osteogenesis, Distraction / methods*
  • Osteogenesis, Distraction / standards*
  • Range of Motion, Articular / physiology
  • Treatment Outcome


  • Anti-Bacterial Agents

Grant support

The institution of MP Jansen, SC Mastbergen and FPJG Lafeber has, during the study period, received funding from: - Dutch Arthris Society (ReumaNederland), project number LLP-9, - ZonMW (The Netherlands Organization for Health Research and Development), project number 95110008, The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.