Hip Cartilage Restoration

What is Hip Cartilage Restoration?

Hip cartilage restoration is a surgical technique to repair damaged articular cartilage in the hip joint by stimulating new growth of cartilage or by transplanting cartilage into areas with defects in order to relieve pain and restore normal function to the hip.

Articular cartilage damage can occur from normal wear and tear of the hip joints, increasing age, injury, or other disease conditions. When cartilage is damaged, it can cause severe pain, inflammation, stiffness, and decreased range of motion of the hip. Because of its avascular nature (absence of blood supply), cartilage cannot repair itself and therefore surgical treatment is usually required to restore cartilage function and prevent progression of the damage into arthritis.

Anatomy of  Articular Cartilage

Articular cartilage is the smooth, shiny, white tissue covering the ends of bones that form a joint. Articular cartilage reduces friction when bones glide over each other, making the movements smooth and painless. It also acts as a shock-absorber to help prevent traumatic injuries to the bones.

Indications for Hip Cartilage Restoration

Hip cartilage restoration is indicated for patients with hip cartilage deterioration or damage as a result of:

• Repetitive use of the hip joint
• Trauma or injury
• Hormonal conditions, such as osteochondritis dissecans (OCD)
• Congenital deformities

Preparation for Hip Cartilage Restoration

Preoperative preparation for hip cartilage restoration will involve the following steps:

• A thorough examination by your doctor to check for any medical issues that need to be addressed prior to surgery.
• Depending on your medical history, social history, and age, routine blood work and imaging may be ordered for safely conducting surgery.
• You will be asked if you have any allergies to medications, anesthesia, or latex.
• You should inform your doctor of any medications, vitamins, or supplements that you may be taking.
• You should refrain from medications or supplements such as blood thinners, aspirin, or anti-inflammatory medicines for a week or two prior to surgery.
• You should refrain from alcohol or tobacco at least 24 hours prior to surgery.
• You should not consume any solids or liquids at least 8 hours prior to surgery.
• Arrange for someone to drive you home as you will not be able to drive yourself post surgery.
• A written consent will be obtained from you after the surgical procedure has been explained in detail.

Surgical Procedures for Hip Cartilage Restoration

Most cartilage restoration procedures can be performed arthroscopically, a minimally invasive surgery that involves making 2 to 3 small keyhole incisions around the hip joint using an arthroscope, a small flexible tube with a light and video camera at the end that enables your surgeon to view inside of the joints and perform surgery. In certain cases, open surgery may be required to access the affected area requiring longer incisions. Your surgeon will discuss the best surgical options for you based on your condition.

Usually, recovery from an arthroscopic procedure is much faster with minimal pain than a traditional, open surgery.

Some of the common hip cartilage restoration procedures include:

• Microfracture: Microfracture technique involves poking multiple holes using arthroscope into the subchondral bone below the cartilage with a sharp tool called an awl. This creates a blood supply to reach the damaged cartilage and stimulates the formation of new cartilage. Young patients with a single lesion and healthy bone are suitable candidates for microfracture procedure.
• Drilling: Drilling is an arthroscopic procedure similar to microfracture in which multiple holes are made in the subchondral bone with the help of a surgical drill or wire to create a healing response. The limiting factor of this procedure is the heat produced by the drilling can injure the surrounding tissues, therefore some surgeons do not recommend this procedure.
• Abrasion Arthroplasty: Abrasion arthroplasty is similar to drilling, but a high-speed metal-like object is used to remove the damaged cartilage instead of drills or wires.
• Autologous Chondrocyte Implantation (ACI): This procedure is accomplished in two steps. The first step involves growing new cartilage cells followed by the implantation of these new cells into the defect area. The first step is performed arthroscopically during which healthy cartilage cells are removed from a non-weight bearing area of the bone. These cells are then cultured in a laboratory for 3-5 weeks to increase their number. Implantation of the new cartilage cells is performed through an open surgical procedure called arthrotomy. Arthrotomy involves preparation of the defect following which a layer of the bone-lining (periosteum) is stitched over the defect and sealed with fibrin glue. The cultured cells are then injected into the defect just below the cover. Autologous chondrocyte implantation is indicated in younger patients who have a single, larger lesion over 2 cm in diameter. As the patient’s own cells are used, there is no risk of tissue rejection.
• Osteochondral Autograft Transplantation: This is a procedure in which healthy cartilage tissue is taken from the non-weight bearing part of the bone and placed into the defect area creating a smoother surface on the cartilage of the joint. This procedure is done for smaller defects and can be performed with arthroscopic technique.
• Osteochondral Allograft Transplantation: Osteochondral allograft transplantation is performed when the cartilage defect is large enough for an allograft to be used. An allograft, a block of cartilage or bone obtained from a deceased donor, is used. The allograft is sterilized and prepared so as to fit exactly into the defect area. This procedure does require a larger, open incision.

Postoperative Care Instructions and Recovery

In general, postoperative care and recovery after hip cartilage restoration involve the following:

• You will be transferred to the recovery area to be monitored until you are awake from the anesthesia.
• Your nurse will monitor your blood oxygen level and other vital signs as you recover.
• You will be placed on assistive devices for the first few weeks with instructions on restricted weight-bearing. You are encouraged to walk with assistance as frequently as possible to prevent blood clots.
• Use of a continuous passive motion machine (CPM) at home is advised during the first few weeks to aid in the constant movement of the joint under a controlled range of motion.
• You are advised to keep your leg elevated while resting to prevent swelling and pain.
• You will notice some pain and discomfort in the hip area. Medications will be provided for comfort.
• Physical therapy and range of motion exercises are advised to restore mobility and strengthen the joints and muscles.
• Anti-nausea medications will be prescribed as needed for discomfort associated with anesthesia.
• You should keep your surgical site clean and dry for at least 48 hours. Instructions on surgical site care and bathing will be provided.
• Refrain from smoking as it can negatively affect the healing process.
• Eating a healthy diet rich in vitamin D is strongly advised to promote healing and a faster recovery.
• Refrain from strenuous activities or lifting heavy objects for the first couple of months. Gradual increase in activities over a period of time is recommended.
• You will be able to return to your normal activities in a month or two; however, return to sports may take 4 to 6 months.
• A follow-up appointment will be scheduled to monitor your progress.

Risks and Complications of Hip Cartilage Restoration

Hip cartilage restoration is a relatively safe procedure; however, as with any surgery, there are risks and complications that could occur, such as:

• Post-operative bleeding 
• Blood clots (deep vein thrombosis)
• Infection 
• Stiffness of the joint
• Numbness around the incisions
• Injury to vessels, nerves, or healthy cartilage
• Allergic response
• Failure of the graft
• Loosening of the graft