K. Mithoefer (Brookline, US)

Presenter Of 1 Presentation

Extended Abstract (for invited Faculty only) Microfracture/Bone Marrow Stimulation

22.0.10 - Marrow Stimulation is Going Strong

Presentation Number
22.0.10
Presentation Topic
Microfracture/Bone Marrow Stimulation
Lecture Time
09:45 - 09:50
Session Type
Plenary Session
Corresponding Author

Abstract

Introduction

Focal articular cartilage defects remain a frequent cause of pain and functional limitation often resulting in surgical intervention. In 1959 Pridie described drilling of the defect as a method to promote healing by recruiting bone marrow elements to reconstitute cartilage lesions. In the 1990’s Steadman introduced the microfracture, technique which still remains the most commonly performed cartilage repair technique to date due to its technical simplicity, limited patient morbidity, and satisfactory overall results. Using the principle of marrow stimulation, the microfracture technique includes debridement of the defect, removal of the calcified cartilage, and penetration of the subchondral bone with specifically designed awls. To date, microfracture is still the “gold-standard” technique against which new cartilage repair technologies are compared. However, it is well recognized that the original microfracture technique is not a panacea, as the repair cartilage formed is biomechanically and histologically different than normal hyaline articular cartilage. Recent studies have shown that the durability of the clinical improvement observed after microfracture can be limited and that some patients may show declining knee function after 18-24 months after surgery. Several reasons have been proposed for this functional deterioration. The limited quality of the fibro-hyaline repair cartilage has been suggested as one factor responsible for the functional deterioration seen in some patients after initial improvement following microfracture. Other factors include the limited repair tissue quantity that can be observed in some patients as well as often limited integration to the surrounding normal articular cartilage tissue. Besides the cartilage repair tissue quantity and quality, changes to the subchondral bone plate including cysts, edema, and more recently subchondral osseous overgrowth have been described and are considered as potential risk factors for the observed functional deterioration after marrow stimulation with microfracture. The phenomenon of bony overgrowth, also referred to as intralesional osteophyte or elevation of subchondral bone plate, is being identified in an increasing number of studies and has recently been shown to increase failure rate after microfracture. Subchondral overgrowth may also play an important role in why secondary cartilage repair procedures such as chondrocyte transplantation may have an increased failure rate after microfracture.

Content

Despite all the limitations of the initial microfracture technique, the principles and efficacy of cartilage repair using marrow stimulation and marrow-derived mesenchymal stem cells are increasingly recognized. Improved scientific understanding of marrow stimulation and mesenchymal stem cell (MSC) technology and its application for joint preservation as well as advances in tissue engineering has led to the development of next-generation technologies that can help to improve the shortcomings of the early-generation marrow stimulation. Several studies have shown that using tissue engineering technology can be very useful in improving tissue quantity and quality after microfracture. Large scale and randomized studies have shown that by using scaffold augmentation with materials such as collagen scaffolds, hydrogels, or allograft cartilage not only consistently increase the amount of repair cartilage fill and peripheral integration but also can produce a more hyaline-like repair tissue quality and were associated with is improved clinical results in randomized controlled comparison to first-generation microfracture with improved durability of the functional improvement. Besides improvements derived from tissue engineering, improvements in the scientific understanding of the effects of marrow stimulation on subchondral bone has resulted in the development of improved techniques for subchondral drilling techniques or nanofracture which in turn have helped to reduce the detrimental subchondral bone effects of early marrow stimulation techniques such as osteocyte necrosis and sealing effect associated with the use of the traditional microfracture awls. Modification of the calcified cartilage removal technique also can reduce subchondral bone stimulation and overgrowth and thereby reducing failure rate. Importantly, a better understanding for the optimal indications for second-generation microfracture or marrow stimulation technology is able to improve both short- and long-term outcomes from this evolving cartilage repair technology and can help to reduce the need for secondary procedures or improve their efficacy. As basic and clinical science of marrow stimulation and MSC continues to evolve, this technology will continue to present a useful and effective tool for joint preservation in the present and future.

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Moderator Of 1 Session

Plaza A Free Papers
Session Type
Free Papers
Date
07.10.2019
Time
14:15 - 15:45
Location
Plaza A

Meeting Participant of

Lord Byron - ICRS Meeting Room (20) ICRS Committee Meeting