Shoulder dislocation can lead to shoulder osteoarthritis through several mechanisms:

1. Cartilage Damage: When the shoulder dislocates, the cartilage in the joint can get damaged. Cartilage provides a smooth surface for the bones to glide over each other. Damage to this cartilage can lead to increased friction and wear and tear, eventually resulting in osteoarthritis.
2. Labral Tears: The labrum is a ring of cartilage around the edge of the shoulder socket that helps stabilize the joint. Dislocation can cause tears in the labrum, which may contribute to instability and increased risk of osteoarthritis.
3. Capsule and Ligament Damage: Dislocation can stretch or tear the ligaments and capsule that hold the shoulder joint together. This can lead to instability of the joint, which in turn can accelerate wear and tear on the joint surfaces, leading to osteoarthritis.

The rate of osteoarthritis development following shoulder dislocation can vary depending on several factors, including the severity of the dislocation, the presence of associated injuries (such as fractures or soft tissue damage), the age of the individual, and their activity level. 

Multiple dislocations can significantly increase the risk of developing osteoarthritis. Each dislocation can cause further damage to the joint structures, accelerating the degenerative process. Studies have shown that the risk of developing osteoarthritis after a single dislocation is relatively low, but with recurrent dislocations, the risk increases substantially.  A study by Hovelius and colleagues published in 2008 examined the long-term outcomes of shoulder dislocations. They found that the risk of developing osteoarthritis after a shoulder dislocation increased with recurrent dislocations. Specifically, they reported that after 25 years following the initial dislocation, approximately 29% of patients who had experienced recurrent shoulder dislocations developed radiographic signs of osteoarthritis.  They also found that individuals who experienced three or more shoulder dislocations had a significantly higher risk of developing osteoarthritis compared to those who experienced one or two dislocations. Specifically, they reported that after 25 years following the initial dislocation, approximately 72% of patients who had experienced three or more shoulder dislocations developed radiographic signs of osteoarthritis. This underscores the substantial increase in osteoarthritis risk associated with recurrent shoulder dislocations.

At Total Orthopedics and Sports Medicine we have orthopedic experts who can evaluate your shoulder dislocation and devise a treatment plan specific to your individual situation.