Clinical Evidence

A level 1 randomized controlled tial was carried out over 10 years with 1, 4 and 10 year follow up. The results of these follow-ups were published in the following three studies.

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Spahn et al, 2008: The first follow-up at 1 year showed faster patient recovery1.
Key results when compared with patients receiving mechanical debridement, those treated with COBLATION experienced:

  • Significantly less knee pain at all follow up points (6 hours to 1 year)
  • 91% reduction in the relative risk of taking NSAID drugs at 1 year for knee pain
  • 24% faster return to work

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Spahn et al, 2010: The second follow-up at 4 years showed better long-term patient outcomes.2
Key Results

  • A significantly higher proportion of revisions for persistent knee problems occurred in the MD group  (p < 0.01;  Figure)
  • Of the patients that did not require revision or replacement surgery (n = 40), those receiving COBLATION had statistically significant improvements compared with MD for:
    − Knee and Osteoarthritis Outcome Score: 71.8 vs  53.2  (p < 0.001)
    − Tegner Score: 4.5 vs 3.3 (p = 0.005)
  • Varus angle on standing was significantly higher in the MD group: 2.3 vs 4.0 (p <  0.001)

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Spahn et al, 2016: The third follow-up at 10 years showed better long-term patient outcomes3.

Key result when compared with patients receiving MD, at 10 years those treated with COBLATION expereinced:

  • A significantly longer mean time to revision
  • A lower overall rate of revision (23.3% v 60.0%; p=0.061)
  • Significantly superior knee injury and osteoarthritis outcome scores (50.8 v 33.1; p<0.001)

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In other studies COBLATION technology has been shown to be safe for use on all knee joint soft tissue types. Two of these studies included an 824 patient (840 lesions) study and a 15 patient (25 lesion second look arthroscopy study.

Gharaibeh et al, 2016: No reported cases of osteonecrosis or chondrolysis and significant improvements in key outcomes measures.4
Key Results:

  • 19 postop complications (2.2%) in 840 cases
  • 23 patients (2.7%) underwent additional surgery within six months
  • No complications or additional surgeries were associated with the use of COBLATION technology
  • Secondary outcome measures indicated that COBLATION chondroplasty significantly improved the key clinical outcomes of KOOS and WOMAC scores (Figure)

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Voloshin et al, 2007
Key Results

  • Mean lesion size decreased from initial procedure to second-look arthroscopy in all lesions (n = 25; Figure 1a) and tibiofemoral joint
    lesions (n = 14; Figure 1b)
    - No tibiofemoral lesions showed any signs of progression
  • The majority of lesions (88%) showed no signs of progressing at second-look arthroscopy, and 56% improved with complete or partial filling

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1. Spahn, G., Kahl, E., Mückley T., Hofmann G.O. & Klinger, H.M. 2008. Arthroscopic chondroplasty using a bipolar radiofrequency-based device compared to mechanical shaver: results of a prospective, randomized, controlled study. Knee Surgery, Sports Traumatology, Arthroscopy (2008) 16: 565-573.
2. Spahn G,, Klinger H.M,, Mückley T, & Hofmann G.O. 2010. Four-year results from a randomized controlled study of knee chondroplasty with concomitant medial meniscectomy: mechanical debridement versus radiofrequency chondroplasty. Arthroscopy. 2010 Sep;26(9 Suppl):S73-80.
3. Spahn, G., Hofmann, G.O. & von Engelhardt, L. V. 2016. Mechanical debridement versus radiofrequency in knee chondroplasty with concomitant medial menisectomy: 10-year results from a randomized controlled study. Knee Surgery, Sports Traumatology, Arrthroscopy. Volume 24, Issue 5; pp. 1560-68.
4. Gharaibeh, M., Szomor A., Chen D.B. & MacDessi, S.J. 2017.  Cartilage. A Retrospective Study Assessing Safety and Efficacy of Bipolar Radiofrequency Ablation for Knee Chondral Lesions. Cartilage. 2017 Apr 1. [Epub ahead of print]
5. Voloshin, I., Morse K.R., Allred, C.D., Bissell, S.A., Maloney, M.D. & DeHaven, K.E. Arthroscopic evaluation of radiofrequency chondroplasty of the knee. American Journal of  Sports Medicine. 2007; 35: 1702-1707.