Distal Tibial Allograft

Dr. Garcia demonstrates his technically advanced technique using a Distal Tibial Allograft (ankle bone) to reduce shoulder dislocations after failed previous shoulder surgeries.

The shoulder joint provides a wide range of movement to the upper extremity but overuse or trauma can cause instability to the joint. The distal tibial allograft procedure is a surgical procedure performed to treat shoulder instability by using a piece of cadaveric ankle bone with an attached tendon to the shoulder joint.

The shoulder joint is a ball and socket joint with the head of the humerus (long arm bone) forming the ball, and a cup shaped depression on the shoulder blade (glenoid fossa) forming the socket.

The joint is stabilized by the labrum, a cartilaginous rim of the glenoid cavity, and the capsule, a series of ligaments that enclose the joint. Injury and trauma can tear or stretch the labrum and/or ligaments, causing instability and dislocation of the joint. The shoulder can dislocate in front (anterior), down (inferior) or behind (posterior), but anterior dislocation is the most common. Tearing of the labrum due to trauma is called a Bankart tear, which sometimes involves the breaking of bone along with the labrum. This is referred to as a bony Bankart tear. Shoulder instability can lead to pain and a feeling of giving way.

Indications

The distal tibial allograft procedure is indicated for anterior shoulder instability that is recurrent and caused by a bony Bankart lesion. Generally, it is used for bone last more than 25%. The surgery is considered when a surgical repair of the labrum does not correct the damage of the shoulder joint.

Procedure

The DTA procedure is performed under general anesthesia with the patient in a semi-reclined or beach-chair position.

• An incision of 5 cm is made from your shoulder blade towards the armpit.
• Retractors are used to separate the muscles of the shoulder and chest
• The cadaveric ankle bone is cut and contoured to fit on the front of the shoulder
• The drill holes are predrilled
• The subscapularis muscle, which passes in front of the shoulder joint is split in line with its fibers.
• The capsule of the shoulder joint is entered and the glenoid is exposed and prepared to receive the allograft.
• The DTA is passed through the separated subscapularis muscle and fixed to the glenoid rim with screws through the previously drilled holes. This increases the glenoid surface and stabilizes the joint. The subscapularis muscle provide additional stability by acting as a sling.
• Upon completion, the instruments are withdrawn, the incision is closed and covered with a sterile bandage.

Post-procedure Care

Following the procedure your arm is placed in a sling to rest the shoulder and promote healing. You may remain in the hospital the night of the surgery before being discharged to home. Pain is controlled with medication and ice packs. You will be instructed to keep the surgical wound dry and to wear your sling while sleeping for a few weeks after the procedure. The sling may be removed in 3 to 6 weeks.

Rehabilitation usually begins early on the first postoperative day with finger movements and passive assisted range of motion exercises. A physical therapy program is recommended for 3 months after which you can return to your regular activities.

Risks and complications

The distal tibial allograft procedure usually provides good results but as with all surgical procedures, complication can occur and include:

• Hematoma (bleeding)
• Fracture or failure of union of the coracoid.
• Stiffness due to inadequate rehabilitation
• Recurrence of instability and infection are rare