Current treatments of isolated articular cartilage lesions of the knee achieve similar outcomes

Abstract

Background: Many surgical techniques, including microfracture, periosteal and perichondral grafts, chondrocyte transplantation, and osteochondral grafts, have been studied in an attempt to restore damaged articular cartilage. However, there is no consensus regarding the best method to repair isolated articular cartilage defects of the knee.

Questions/purposes: We compared postoperative functional outcomes, followup MRI appearance, and arthroscopic examination after microfracture (MF), osteochondral autograft transplantation (OAT), or autologous chondrocyte implantation (ACI).

Methods: We prospectively investigated 30 knees with MF, 22 with OAT, and 18 with ACI. Minimum followup was 3 years (mean, 5 years; range, 3-10 years). We included only patients with isolated cartilage defects and without other knee injuries. The three procedures were compared in terms of function using the Lysholm knee evaluation scale, Tegner activity scale, and Hospital for Special Surgery (HSS) score; modified Outerbridge cartilage grades using MRI; and International Cartilage Repair Society (ICRS) repair grade using arthroscopy.

Results: All three procedures showed improvement in functional scores. There were no differences in functional scores and postoperative MRI grades among the groups. Arthroscopy at 1 year showed excellent or good results in 80% after MF, 82% after OAT, and 80% after ACI. Our study did not show a clear benefit of either ACI or OAT over MF.

Conclusions: Owing to a lack of superiority of any one treatment, we believe MF is a reasonable option as a first-line therapy given its ease and affordability relative to ACI or OAT.

Level of evidence: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Fig. 1

The overall Lysholm, Tegner, and HSS clinical scores at postoperative 5 years are shown. MF = microfracture; OAT = osteochondral autograft transplantation; ACI = autologous chondrocyte implantation; HSS = Hospital for Special Surgery; * p > 0.05.

Fig. 2A–B

(A) A preoperative MR image shows collapse of the weightbearing surface of the medial femoral condyle in a 51-year-old woman with a cartilage defect of the right knee. (B) Twelve months after the MF procedure, the articular contour of the medial femoral condyle is restored.

Fig. 3A–B

(A) This preoperative MR image shows collapse of the weightbearing surface of the lateral femoral condyle in an 18-year-old woman with a cartilage defect of the right knee. (B) One year after OAT of the lateral femoral condyle, the articular contour is congruent, but a subchondral cyst is seen.

Fig. 4A–B

(A) A preoperative arthroscopic image shows a Grade 4 cartilage defect. (B) Thirteen months after our patient, a 22-year-old man, underwent ACI of the lateral femoral condyle, a Grade 2 articular cartilage lesion with good coverage can be seen.