Microfracture is a simple but cost-effective procedure performed to treat smaller cartilage injuries. It is not used to address defects with damage to the underlying bone. It also cannot be used to treat widespread arthritis in a joint. But it is an excellent choice as an initial treatment of smaller articular cartilage injuries.
After the microfracture repair of the knee, the post-operative recovery period is fairly complication-free. After the procedure has been performed in the patella and the trochlear groove, there will likely be mild transient pain or “gritty” sensation. The pain resolves sooner but the gritty sensation typically resolves with a few weeks. Patients may notice “catching” as the ridge of the patella rides over this area during joint motion. This may be apparent during continuous passive motion machine (CPM). If it is also painful, it is best to limit weight bearing; it should resolve within 3 months. Any residual swelling and joint effusion disappears within 8 weeks after microfracture. Sometimes, there is a recurrent effusion between 6 to 8 weeks after surgery but it is usually painless and typically resolves within several weeks.
The rehabilitation process is vital to the long-term success and functional outcome of these patients. Postoperative rehabilitation programs for microfracture procedures vary greatly based on lesion size, depth, location, quality of tissue, patient age, BMI, general health, and surgical details. Thus, the appropriate rehabilitation program must be highly individualized to ensure successful outcomes. The goal of rehabilitation is to restore full function in the shortest time possible without overloading the healing articular cartilage. It is imperative to create a healing environment while avoiding deleterious forces that may overload the healing tissue.
In order for microfracture to work consistently, the healing tissue must be stimulated to form cartilage rapidly and durably. The progenitor/stem cells and bone paste can be added to a super microfracture of the lesion in a technique called Paste grafting. The healing process can be augmented by injections of growth factors and hyaluronic acid lubrication injections during the healing period.
The studies are showing mid-term and long-term success for microfracture in the knee. Multisite microfracture was seen to have poorer outcomes. This is likely because multiple cartilage injuries are indicative of a more advanced disease process. It has been found that patients younger than 45 years had significantly improved outcomes after microfracture as compared with those older than 45 years. Patient age and BMI have been found to be significant predictors of postoperative improvement after microfracture.
Overall, presence of a single cartilage lesion, lower BMI, or being a male has been found to result in greater functional improvement after microfracture. Moreover, larger defects (>3.6 sq.cm) and prior surgery were both independent predictors for future surgery after microfracture.