Current concepts of articular cartilage restoration techniques in the knee

Abstract

Context: Articular cartilage injuries are common in patients presenting to surgeons with primary complaints of knee pain or mechanical symptoms. Treatment options include comprehensive nonoperative management, palliative surgery, joint preservation operations, and arthroplasty.

Evidence acquisition: A MEDLINE search on articular cartilage restoration techniques of the knee was conducted to identify outcome studies published from 1993 to 2013. Special emphasis was given to Level 1 and 2 published studies.

Study design: Clinical review.

Level of evidence: Level 3.

Results: CURRENT SURGICAL OPTIONS WITH DOCUMENTED OUTCOMES IN TREATING CHONDRAL INJURIES IN THE KNEE INCLUDE THE FOLLOWING: microfracture, osteochondral autograft transfer, osteochondral allograft transplant, and autologous chondrocyte transplantation. Generally, results are favorable regarding patient satisfaction and return to sport when proper treatment algorithms and surgical techniques are followed, with 52% to 96% of patients demonstrating good to excellent clinical outcomes and 66% to 91% returning to sport at preinjury levels.

Conclusion: Clinical, functional, and radiographic outcomes may be improved in the majority of patients with articular cartilage restoration surgery; however, some patients may not fully return to their preinjury activity levels postoperatively. In active and athletic patient populations, biological techniques that restore the articular surface may be options that provide symptom relief and return patients to their prior levels of function.

Keywords: autologous chondrocyte implantation; cartilage injuries; knee; microfracture; osteochondral allograft transplant; osteochondral autograft transfer.

Figure 1.

(a) Sagittal and (b) axial MRI of chondral defect measuring 11 × 10 mm.

Figure 2.

Treatment algorithm. Younger, <40 years old; older, 40-50 years old; MFX, microfracture; OAT, osteochondral autograft transfer; OCA, osteochondral allograft transplantation; ACI, autologous chondrocyte implantation; *, consider anteromedialization tibial tubercle osteotomy; ++, based on level 1/2 recommendations; +, based on level 3/4 recommendations; +/-, consider option depending on individual patient characteristics. Adapted from Cole et al.

Figure 3.

Example of a right distal femoral osteotomy to correct valgus malalignment and off-load the lateral compartment of the knee. (a) Preoperative x-ray, (b) postoperative x-ray, (c) preoperative clinical photograph, and (d) postoperative clinical photograph of patients undergoing distal femoral osteotomy.

Figure 4.

Microfracture case demonstrating (a) a condylar cartilage defect that is (b) debrided to a clean base with a healthy stable rim of supporting chondral tissue. (c) Following microfracture, the inflow is turned off to demonstrate initial influx of marrow products.

Figure 5.

Osteochondral autograft transfer (OAT) highlighting (a) a lesion of the medial femoral condyle after debridement and (b) subsequent OAT utilizing a mosaicplasty technique.

Figure 6.

(a) Example of osteochondral allograft transplantation used to treat a large chondral lesion of the medial femoral condyle. (b) The site was prepared to receive the first plug in the posterior position. After this was placed, it was determined that an additional plug was needed anteriorly. (c) The site was prepared for a second plug, which was subsequently placed anterior to the first utilizing the mosaicplasty technique.

Figure 7.

Example of a full-thickness patellar defect treated with autologous chondrocyte implantation. (a) The initial biopsy obtained during the first stage was taken from the superolateral trochlea. (b) During the second stage of the procedure, the patella was completely everted though an arthrotomy and the lesion readily identified. (c) This was thoroughly debrided, and (d) a collagen patch was sewn into place leaving a small opening in the superior portion for cell injection.