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THU0472 Six Weeks of Knee Joint Distraction: Sufficient for Cartilage Tissue Repair
  1. J.-T. van der Woude1,
  2. R.J. van Heerwaarden2,
  3. K. Wiegant1,
  4. P.M. van Roermund3,
  5. D.B. Saris4,
  6. S.C. Mastbergen1,
  7. F.P. Lafeber1
  1. 1Rheumatology & Clinical Immunology, UMC Utrecht, Utrecht
  2. 2Orthopedics, Maartenskliniek, Woerden
  3. 3Orthopedics, Medical Centre Amstelveen, Amstelveen
  4. 4Orthopedics, UMC Utrecht, Utrecht, Netherlands


Background In osteoarthritis knee joint distraction (KJD) provides clinical benefit and tissue structure modification at 1 year and beyond. During the previous regime of an 8-week distraction period patients visited every 2 weeks day care practice for temporarily removal of the distraction frame. 8 weeks of intermittent KJD with frequent hospital visits is perceived as a considerable burden. This study evaluates whether 6 weeks of continuous KJD gives similar tissue structure repair and clinical benefit compared to eight weeks of KJD at 1-year follow-up.

Methods Both groups consisted of 20 patients with knee OA and were treated with 5 mm joint distraction by use of an external fixator for 8 weeks with every 2 weeks CPM or 6 weeks continuously. WOMAC questionnaires were assessed, representing the clinical outcome. Structural outcome was quantified as mean joint space width (JSW) on standardized semi-flexed x-rays at baseline and one-year of follow-up using KIDA. T-tests were applied to analyze change over time.

Results Clinical improvement compared to baseline (BL) was observed in both groups. The 6-week group showed a comparable increase from 53±17 points at BL to 76±17 points at one-year follow up (p<0.001) as the 8-week group (from 45±16 points at BL to 77±21 points at the 1-year follow-up; p<0.001). The structural parameters revealed parallel improvements between both groups. The mean JSW of the most affected compartment of the six-week group increased from 1.80±1.61mm to 2.86±1.59mm at 1 year (p=0.001) vs. 2.63±1.62mm to 3.55±0.99mm at 1 year (p=0.006) for the 8-week group. No significant statistical difference between the two groups (p=0.729) was observed.

Conclusions Six weeks of continuous KJD gives significant clinical and structural improvement. Moreover, 6-weeks of continuous distraction treatment does not lead to a stiffer knee in comparison with the “intermittent” 8-week treatment.

Acknowledgements ZonMw (The Netherlands Organisation for Health Research and Development) and the Dutch Arthritis Association support this study.

Disclosure of Interest None declared

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