Subchondral bone lesions may be clinically important, treatable with bone substitute
Subchondroplasty, an arthroscopic procedure to inject a bone substitute material into chronic bone marrow lesions, may yield clinically significant and durable improvement in pain among patients with knee osteoarthritis, according to a surgeon who helped develop the procedure.
According to Peter F. Sharkey, MD, patients with painful knee OA may develop chronic bone marrow lesions that are localized to the subchondral bone adjacent to the arthritic articular surface of the knee and can be recognized on fluid-sensitive fat-suppressed MRI sequences.
In terms of treatment, he and his colleagues perform subchondroplasty using a cannula to inject a bone substitute into the damaged area where these bone marrow lesions are present. However, the bone substitute used must have the capacity for biologic remodeling of bone.
Although some orthopedic surgeons may believe it is easy to perform subchondroplasty, Sharkey said there are tricks and nuances of which anyone attempting this surgery should be aware.
“Do not underestimate this procedure,” Sharkey told Healio.com/Orthopedics. “It is not as simple as it looks and there definitely are technical challenges, and it has to be done correctly.”
For example, Sharkey and his colleagues who perform subchondroplasty take steps to avoid compromising any future total knee arthroplasty surgery these patients might undergo.
Furthermore, “if you inject the bone substitute and it is not in the proper place, it is not going to fill the void,” Sharkey told Healio.com/Orthopedics.
Aided by imaging
Performing subchondroplasty requires obtaining 3D MRI and two-dimensional fluoroscopy of the patient’s knee and planning the injection based on the location of the lesion(s), Sharkey said.
“One of the hardest things for surgeons to do is learn how to look at 3D MRI and then go to the OR and … now using two-dimensional fluoroscopy and identify the correct place to inject,” he said in the interview with Healio.com/Orthopedics.
It is also helpful when learning this procedure to take a class or observe a visiting surgeon who treats a lot of patients with these lesions, Sharkey said.
Understanding the lesions
According to Sharkey, extensive literature has shown these lesions can lead to altered histology and structure in a region of the bone, as well as predict disease progression, making them clinically important.
Furthermore, they are associated with accelerated cartilage loss and progressive deformity, as well as subchondral bone attrition, which is remodeling of the subchondral bone below arthritis lesions, he said.
In a study by Steven B. Cohen, MD, and Sharkey published in 2016, 66 patients with advanced OA and a bone marrow lesion had significant improvements in pain and function following subchondroplasty with arthroscopic debridement.
“Given that arthroscopic debridement alone has been previously shown to yield insignificant pain relief beyond 6 months postoperatively, our results suggest that subchondroplasty may be a promising approach for the treatment of OA with [bone marrow lesions] BMLs,” the authors wrote. – by Susan M. Rapp and Casey Tingle
Cohen SB, et al. J Knee Surg. 2016;doi:10.1055/s-0035-1568988.
Disclosure: Sharkey reports he receives royalties from and is a consultant for Zimmer Biomet and Corentec Co. Ltd.