What is Humeral Head Reconstruction with Osteochondral Allograft Transplantation?
Humeral head reconstruction with osteochondral allograft transplantation is a surgical technique employed in the treatment of large osteochondral defects of the humeral head or large Hill-Sachs lesions with or without glenoid bone loss. The surgery helps to restore the cartilage surface of the humeral head, improve stability and function to the shoulder joint, and prevent recurrent dislocations.
Osteochondral grafting is a method of treating cartilage injuries that expose the underlying bone. An osteochondral allograft is a piece of tissue containing bone and cartilage that is taken from a deceased donor to replace damaged cartilage that lines the ends of bones in a joint. The allograft tissue is shaped to precisely fit the defect in the damaged joint of the patient and then transplanted to repair the damage.
Anatomy of the Shoulder
The shoulder is a ball and socket joint where the ball is formed by the head of the upper arm bone or humerus and the socket is formed by a shallow cavity in the shoulder blade called the glenoid. The glenoid is surrounded by a raised ridge of fibrous cartilage called the labrum which provides some depth to the socket increasing the stability of the joint. Stability is further enhanced by ligaments that form a capsule around the joint, as well as muscles and tendons which center the humeral head in the socket.
Indications for Humeral Head Reconstruction with Osteochondral Allograft Transplantation
Your surgeon may recommend humeral head reconstruction with osteochondral allograft transplantation for the following conditions, including:
- Hill-Sachs lesions: Damage to the back and outer portion of the humeral head can result in a defect called a Hill-Sachs lesion. A Hill-Sachs lesion usually occurs when the humeral head dislocates towards the front of the joint.
- Shoulder instability: Shoulder instability is a chronic condition that causes frequent dislocation of the shoulder joint. A dislocation occurs when the end of the humerus (ball portion) partially or completely dislocates from the glenoid (socket portion) of the shoulder.
- Bankart tear or injury: A specific type of labral tear that occurs when the shoulder dislocates is called a Bankart tear. This is a tear to a part of the labrum called the inferior glenohumeral ligament and is common in the young who sustain a dislocation of the shoulder.
- Failure of the non-surgical treatment such as immobilization
Preparation for Humeral Head Reconstruction with Osteochondral Allograft Transplantation
Preoperative preparation for humeral head reconstruction with osteochondral allograft transplantation may involve the following steps:
- A thorough examination is performed 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, you may need to undergo tests such as bloodwork and imaging to screen for any abnormalities that could compromise the safety of the procedure.
- You will be asked if you have allergies to medications, anesthesia, or latex.
- You should inform your doctor of any medications, vitamins, or supplements that you are taking.
- You may need to refrain from supplements or medications such as blood thinners or anti-inflammatories for a week or two prior to surgery.
- You should refrain from alcohol or tobacco at least a few days prior to surgery.
- You should not consume solids or liquids at least 8 hours prior to surgery.
- A written consent will be obtained from you after the surgical procedure has been explained in detail.
Procedure for Humeral Head Reconstruction with Osteochondral Allograft Transplantation
The implantation of osteochondral allografts is usually performed through an open incision, under general or spinal anesthesia. An incision is made to expose the joint defect. The size of the defect is then measured, and a portion of the cartilage and underlying bone is removed. A fresh allograft taken from a deceased donor is sterilized, prepared in the laboratory, and tested for risk of disease transmission. It is then trimmed with an oscillating saw to match the size of the prepared defect. The allograft is then gently press-fit into the defect created in the recipient's bone. It can be further stabilized with metallic screws and pins if needed. The incision is then closed, and a dressing is applied to the joint.
In general, humeral head reconstruction with osteochondral allograft transplantation involves the following steps:
- Your surgeon makes a long incision over the shoulder joint and cuts through the soft tissues in order to gain access to the interior of the joint.
- Retractors are used to hold the tissue apart so the surgeon can view the damage in the joint.
- Your surgeon then performs debridement of the humeral head to remove damaged cartilage and bone. Care is taken to prevent damage to healthy cartilage and bone tissue.
- A thoroughly prepared fresh or frozen osteochondral allograft obtained from the femoral or humeral head area is then transplanted into the section of humeral head defects and allowed to grow.
- Your surgeon may also use pins, plates, or screws to secure the osteochondral allograft in place.
- Intraoperative fluoroscopy is performed by your surgeon to confirm proper placement of the graft.
- The incision is closed and covered with a bandage.
Postoperative Care Instructions and Recovery
In general, postoperative care instructions and recovery after humeral head reconstruction with osteochondral allograft transplantation involves the following steps:
- 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 may notice some pain, swelling, and discomfort in the shoulder area. Pain and anti-inflammatory medications are provided as needed.
- Antibiotics are also prescribed for risk of infection associated with surgery.
- You may also apply ice packs on the shoulder to help reduce swelling and pain.
- Your arm may be secured with assistive devices such as a sling for the first few weeks to facilitate healing.
- You are advised to walk as frequently as possible to prevent the risk of blood clots.
- Keep your surgical site clean and dry. Instructions on surgical site care and bathing will be provided.
- Refrain from smoking as it can negatively affect the healing process.
- Refrain from strenuous activities and lifting heavy weights for a month or two. Gradual increase in activities over a period of time is recommended.
- An individualized physical therapy protocol is designed to help strengthen your shoulder muscles and optimize shoulder function.
- You will be able to resume your normal activities in a couple of months; however, return to sports may take about 6 months or longer.
- Refrain from driving until you are fully fit and receive your doctor’s consent.
- A periodic follow-up appointment will be scheduled to monitor your progress.
Risks and Complications
Humeral head reconstruction with osteochondral allograft transplantation is a relatively safe procedure; however, as with any surgery, some risks and complications may occur, such as:
- Infection
- Bleeding
- Rejection of the bone graft
- Damage to surrounding structures
- Poor bone healing
- Joint stiffness
- Wear or loosening of the bone graft
- Allograft necrosis and resorption
- Glenohumeral arthritic changes
- The need for re-operation