Table 2 Details of clinical studies in knee lesions

Gharaibeh et al. (2017)

Level IV, retrospective case series

RFE: 840

Up to 6 months

Most common site of chondral lesion: - Medial femoral condyle (27%)

- Patella (21%)

- Trochlea (9%)

Postoperative complications: 2.2%

Required reoperation: 2.7%

Significant improvement in KOOS and WOMAC scores from preoperative to 129 days postoperative (p < 0.0001)

Owens et al. (2002)

Level I, RCT

RFE: 20

MD: 19

Up to 24 months

Isolated patellar chondral lesions (Outerbridge Grade II or III)

Fulkerson-Shea score: superior for radiofrequency over mechanical debridement at 24 months (p = 0.0006)

Spahn et al. (2008)

Level I, RCT

RFE: 30

MD: 30

Up to 12 months

Cartilage defect(s) of the medial femoral condyle (Outerbridge Grade III)

Significantly better KOOS (p < 0.001) and Tegner scores (p < 0.001) for RFE over MD at 12 months

Significantly lower VAS pain score (p = 0.014) for RFE over MD at 12 months

Spahn et al.^a (2010)

Level I, RCT

RFE: 25

MD: 15

Up to 48 months

Cartilage defect(s) of the medial femoral condyle (Outerbridge Grade III)

Significantly higher proportion of revisions for persistent knee problems occurred in the MD group than RFE group (4 vs 14; p < 0.01)

Significantly better KOOS (p < 0.001) and Tegner scores (p = 0.005) for RFE over MD at 48 months^b

Spahn et al.^a (2016b)

Level I, RCT

RFE: 13

MD: 9

Up to 120 months

Cartilage defect(s) of the medial femoral condyle (Outerbridge Grade III)

Significantly longer mean time to revision for RFE group over MD group at up to 120 months (94.1 vs 62.5 months; p = 0.022)

Voloshin et al. (2007)

Level IV, retrospective case series

RFE: 193

Not reported

Partial-thickness articular cartilage lesions (Outerbridge Grade I-IV)

Second-look follow-up arthroscopy of 25 lesions showed 12% with progressive deterioration, 32% with no change, 32% with partial filling of the defect, and 24% with complete filling with stable repair tissue