Use of Mesenchymal Stem Cells for Osteochondral Lesions of the Talus

Niall A. Smyth and John G. Kennedy

Disclosures

Curr Orthop Pract. 2013;24(5):461-464. 

In This Article

Abstract and Introduction

Abstract

The ankle is one of the most commonly injured joints in athletic individuals, with a sprain being the most frequent mechanism of injury. With the advent of advanced medical imaging techniques, surgeons have recognized that these injuries may to lead to cartilage insult in up to 50% of patients, which potentially leads to the formation of an osteochondral lesion of the talus. Suboptimal results after the primary treatment method, bone marrow stimulation, have been frequently reported in clinical studies. Therefore, the orthopaedic research community has sought to improve on the results by applying cell-based tissue engineering in the form of adding mesenchymal stem cells (MSC) to the repair site. Although still in its nascent stages, we present the current clinical evidence regarding the use of MSCs for osteochondral lesions of the talus.

Introduction

Ankle sprains are frequent injuries in sports,[1,2] which can lead to cartilage injury in up to 50% of patients[3] and to the formation of an osteochondral lesion of the talus (OCL) (Figure 1). As articular hyaline cartilage is avascular, once damaged it has a poor propensity for healing.[4,5] This has led to a multitude of surgical treatment modalities that attempt to heal cartilage lesions through either reparative or replacement techniques.[6,7] The primary surgical treatment modality for OCLs is arthroscopic bone marrow stimulation (e.g. microfracture), with which the aim is to penetrate the subchondral plate to recruit mesenchymal stem cells (MSC) to the repair site.[8] These MSCs differentiate into chondrocyte-like cells that deposit a proteoglycan type-II collagen matrix. However, this repair eventually transitions into fibrocartilage and potentially deteriorates over time.[9,10] Suboptimal results after bone marrow stimulation have been frequently reported in clinical studies. On second-look arthroscopy after bone marrow stimulation, Lee et al.[11] found at 12 months postoperatively that 35% of ankles showed incomplete healing, only 30% of lesions were integrated with the native hyaline cartilage, and 80% had cracks and fissures. Becher et al.[12] echoed these results when assessing the outcome of microfracture surgery using MRI, reporting that 100% of the cases had cracks and fissuring of the regenerative tissue at a mean follow-up of 5.8 years. Therefore, the orthopaedic research community has sought to improve on the results by applying cell-based tissue engineering in the form of adding MSCs to the repair site.

Figure 1.

MRI of an osteochondral lesion of the medial talar dome.

MSCs are nonhematopoietic stromal cells with multilineage differentiation potential. The concept of their use for musculoskeletal indications was first developed by Alexander Friedenstein over 50 years ago;[13] however, it is only recently that research has proliferated regarding their clinical use in cartilage repair. Currently, many autogenous sources are used for MSC retrieval, with varying concentrations and differing methods of clinical application. The objective of this paper is to summarize the current state of MSC use for osteochondral lesions of the talus.

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