Bone Marrow Lesions (BML) are MRI-visible defects in the subchondral bone. BML can only be seen on fat-suppressed MRI sequences (T2FS, PDFS, etc.) where they appear as a hazy white area against the background of darker bone. Pathologists have shown that BML represent a healing response to trauma such as micro-trabecular fractures of the subchondral bone.

In these patients, current treatment guidelines recommend an initial course of conservative care which may heal the defect. If the defect remains, The Subchondroplasty® (SCP®) Procedure may be an option.

During The SCP® Procedure, AccuFill® BSM, an injectable, flowable, engineered calcium phosphate bone substitute is used to fill a subchondral bone defect. AccuFill® BSM crystallizes and hardens in an endothermic reaction at 37° C to form a nanocrystalline, macroporous scaffold in the bone. Over time, through cell-mediated remodeling, AccuFill® BSM is resorbed and replaced with new bone.

Do You Need a Subchondroplasty?

Conservative treatment is generally the proper course for a subchondral fracture. However, many patients fail nonoperative treatment and would benefit from this procedure. As always, a complete assessment of possible risks should be discussed before making the decision to have surgery.

Patients typically present with:

Presence of bone defect seen on fat-suppressed MRI (T2FS, PDFS, STIR, etc.)

No resolution of Bone Marrow Lesion with conservative care or other intervention and continue to have pain.

How the Subchondroplasty Procedure Works?

The Subchondroplasty Procedure, often performed along with arthroscopy, is a minimally-invasive, fluoroscopically-assisted procedure. The SCP Procedure targets and fills subchondral bone defects often called Bone Marrow Lesions (BML) in patients who have not responded to conservative treatment.

AccuFill® Injectable Bone Substitute Material is an injectable, self-setting, macroporous, osteoconductive, calcium phosphate bone graft substitute material that is intended for use to fill bony voids or gaps of the skeletal system of the extremities, spine (i.e. posterolateral spine), and pelvis that are not intrinsic to the stability of the bony structure. These defects may be surgically created osseous defects or osseous defects created from traumatic injury to the bone. AccuFill® Injectable Bone Substitute Material is a bone graft substitute that resorbs and is replaced with new bone during the healing process.

Length of Recovery Period

Since the procedure is minimally invasive, there is an expedited recovery. I often keep patients non weight bearing for 7-10 days and then transition to weight bearing as tolerated in a walking boot. The Accufill sets hard within 24 hours which allows a more aggressive approach to postoperative rehabilitation. We have treated some patients that have been full weight bearing without pain at 2 weeks.