Osteochondral Lesions Under 15mm2 of the Talus; is Iliac Crest Bone Marrow Aspirate Concentrate the Key to Success?

Osteochondral defects (OCDs) of the talus have a significant impact on the quality of life of patients. When OCDs are of small nature (up to 15 mm in diameter), and have failed conservative management, surgical intervention may be necessary. For small cystic defects the current treatment is an arthroscopic bone marrow stimulation (BMS) procedure, during which the damaged cartilage is resected and the subchondral bone is microfractured (MF), in order to disrupt intraosseous blood vessels and thereby introduce blood and bone marrow cells into the debrided lesion, forming a microfracture fibrin clot, which contains a dilute stem cell population from the underlying bone marrow. This procedure has been reported to have a 75% successful long-term outcome. Recently, the additional use of biological adjuncts has become popular, one of them being bone marrow aspirate concentrate (BMAC) from the iliac crest. BMAC consists of mesenchymal stem cells, hematopoietic stem cells and growth factors, which may therefore theoretically improve the quality of subchondral plate and cartilage repair. The current evidence for treating talar OCDs with BMS plus BMAC is limited and heterogeneous. It is unclear to what extent the treatment of talar OCDs with BMS plus BMAC is beneficial in comparison to BMS alone.

Osteochondral defects (OCDs) of the talus have a significant impact on the quality of life of patients. When OCDs are of small nature (up to 15 mm in diameter), and have failed conservative management, surgical intervention may be necessary. For small cystic defects the current treatment is an arthroscopic bone marrow stimulation (BMS) procedure, during which the damaged cartilage is resected and the subchondral bone is microfractured (MF), in order to disrupt intraosseous blood vessels and thereby introduce blood and bone marrow cells into the debrided lesion, forming a microfracture fibrin clot, which contains a dilute stem cell population from the underlying bone marrow. This procedure has been reported to have a 75% successful long-term outcome. Recently, the additional use of biological adjuncts has become popular, one of them being bone marrow aspirate concentrate (BMAC) from the iliac crest. BMAC consists of mesenchymal stem cells, hematopoietic stem cells and growth factors, which may therefore theoretically improve the quality of subchondral plate and cartilage repair. The current evidence for treating talar OCDs with BMS plus BMAC is limited and heterogeneous. It is unclear to what extent the treatment of talar OCDs with BMS plus BMAC is beneficial in comparison to BMS alone.

Eligibility Criteria:
Inclusion Criteria:

* Patients with a symptomatic OCL of the talus who are scheduled for arthroscopic debridement and microfracture
* OCL depth and/or diameter ≤ 15 mm on computed tomography medial-lateral and/or anterior-posterior
* Age 18 years or older
* Intact remaining articular cartilage of the joint Kellgren-Lawrence stage 0-1

Exclusion Criteria:

* Concomitant OCL of the tibia
* Ankle osteoarthritis grade 2 or 3 van Dijk et al. \[53\]
* Ankle fracture \< 6 months before scheduled arthroscopy
* Inflammatory arthropathy (e.g Rheumatoid arthritis)
* History of (or current) hemopoeitic disease or immunotherapy
* Acute or chronic instability of the ankle
* Use of prescribed orthopaedic shoewear
* Other concomitant painful or disabling disease of the lower limb
* Pregnancy
* Implanted pacemaker
* Participation in previous trials \< 1 year, in which the subject has been exposed to radiation (radiographs or CT)
* Patients who are unable to fill out questionnaires and cannot have them filled out
* No informed consent
* HIV positive or hepatitis B or C infection (based on the anamnesis of the patient)