Patients who have subchondral bone defects—also known as Bone Marrow Lesions (BML)—may be candidates for a new, minimally-invasive surgery called the Subchondroplasty (SCP®) Procedure. This technique targets and fills bone defects with a hard-setting bone substitute material (BSM) with physical and chemical properties similar to cancellous bone. As the body heals the defect, the BSM will be replaced with new bone.
Bone Marrow Lesion of the Knee
What is a Bone Marrow Lesion?
BML defects are often-painful defects of the spongy cancellous bone near a joint. They can be found in the bone near any joint that experiences weight-bearing or repetitive motion stress and strain. In some patients, these defects are a result of a bone injury that doesn’t heal properly. In others, BML defects are a stress reaction from overuse or altered joint mechanics.
BML are typically not visible on X-rays. They are diagnosed using certain types of MRI, where they appear as a hazy white area against the background of darker bone. Pathologists have shown that these BML represent a healing response surrounding trauma, such as microtrabecular fractures of the subchondral bone.
If this healing response fails, physicians usually recommend a course of conservative care, including pain meds, crutches, joint braces, injections, among others. In some patients, this treatment will allow the body to heal the subchondral bone defect. If conservative care is unsuccessful, however, the SCP® procedure may be an option.
The Surgical Process
The SCP® Procedure is usually performed in an outpatient setting, with patients returning home the same day of the procedure. The procedure is usually performed with arthroscopy (“scoping”) of the nearby joint, to allow for treatment of any pathology inside the joint. You will be anesthetized for the procedure. During the SCP® surgery, a small, drillable cannula is inserted minimally-invasively into the area of the bone defect. Intraoperative X-ray is used to assist with targeting the defect.
Target subchondral bone defect using SCP® Navigation Guide
Access bone defect using AccuPort® Delivery Cannula®
Inject AccuFill® BSM into the defect. AccuFill® BSM is a flowable, injectable bone void filler that is replaced with new bone during the healing process.
AccuFill® Bone Substitute Material is then hydrated and mixed into an injectable paste, and is delivered through the cannula to fill the bone defect. Once the BSM has hardened, the cannulas are removed and surgical wounds closed.
AccuFill® BSM injection into the defect
After the procedure, AccuFill® BSM is replaced with new bone during the healing process
Discuss treatment options and potential risks with your surgeon. It is important that you fully understand all risks and benefits before making a decision to have surgery. Only your doctor can tell you if The Subchondroplasty® Procedure may be right for you.
As with every surgical procedure, there are risks and potential complications. Individual results may vary. Success depends on factors such as age, weight and activity level.
What to Expect After Surgery
Postoperatively, a short recovery course is recommended, similar to that of arthroscopy.
It’s important to note that recovery from The SCP® Procedure is different for every patient. However, the following is common for most patients:
- For the first 48–72 hours after The SCP® Procedure, patients will often experience significant pain in the operative area. Your doctor will likely prescribe pain medication to treat these symptoms. Follow your doctor’s advice closely.
- For the initial period, most doctors will recommend walking and standing with crutch support. The use of crutches is typically reduced as tolerated.
- Your doctor will also recommend a course of physical therapy and activities to help you regain strength and maintain mobility of your joint.
It is important to follow the advice of your doctor as you recover.