The patient is placed in the surgeon’s normal preferential position for knee arthroscopy. A tourniquet is placed at the root of the limb to limit bleeding. The standard, anterolateral and anteromedial arthroscopic portals are used to reach the knee joint. It is better to complete all other procedures on the knee before HYALOFAST® application (i.e. the scaffold insertion should be the last procedure before termination of the operation as the application needs to be in a ‘dry’ environment).
LESION CLEANING AND MEASURING
After joint inspection, the lesion is carefully debrided removing unstable cartilage back to a stable chondral rim. This is best done with an arthroscopic curette and/or spoon and/or a motorized burr. The lesion should be debrided to the subchondral bone. When a well contained defect with a stable shoulder is achieved, measure the lesion with a calibrated arthroscopic probe.
Hyalofast is cut with sterile scissors to fit the lesion shape. Thanks to the high conformability of the implant, a precise cut is not necessary. It is better if the membrane is 5-10% larger than the lesion size.
Note: Cutting dry HYALOFAST is easier than when it is wet from containing fluid
MICROFRACTURING OR BONE MARROW ASPIRATE LOADING
Hyalofast can be applied as it is, in combination with microfracture/nanofracture procedure at the base of the lesion or loaded with BMAC if preferred.
- If using Hyalofast + BMAC, load BMAC on the scaffold before implantation.
- If using Hyalofast + microfracture/nanofracture, then perform microfracture according to the approved clinical practice, or use Nanofracture procedure according to the specific protocol.
- Switch fluid management system off and drain the knee joint of any fluid. If a suitable cannula is available, the Hyalofast can be passed into the cannula with the help of a probe
- Use the probe to slide the Hyalofast into the joint and onto the lesion, and then to position it more accurately within the margins of the lesion.
- Remove the cannula if used and make any final positioning adjustments to the Hyalofast using a flat probe. It is important that the product remains confined inside the lesion margins, not overlapping the adjacent cartilage. If preferred, Hyalofast can be applied via direct access with the help of a smooth grasper
- If the lesion is not too large and well shouldered there is no need of additional fixation. If required, fibrin glue can be applied on margins or on top to enhance the stability of the implant.
Hyalofast can be applied on both sides and stacked in case of osteochondral lesions with medium entity bone involvement (>5 mm). Overlapping of two/three pads could be used as long as the total thickness of the implant is not greater than the depth of the defect.
For osteochondral lesions with a particularly deep (>8 mm) bone defect, before applying Hyalofast, it is suggested to perform an additional step to fill the bone gap with bone chips kept in place with platelet gel. Hyalofast can be then applied on top of the bone graft.
SCAFFOLD STABILITY VERIFICATION
After Hyalofast application, the joint is mobilized with 5-6 flexion-extension cycles under arthroscopic control to ensure adherence and stability prior to standard closure of the surgical incision