Anti-dislocation Dual Mobility Acetabular System

Anti-dislocation Dual Mobility Acetabular System prosthesis consists of an acetabular outer shell, a metal liner, a mobile polyethylene liner, and a Femoral Head. It offers advantages such as ease of operation, stability, safety, and improved postoperative mobility. It falls under the category of non-standardized products.

Currently, DM cups are a well-accepted treatment option for any patient at an elevated risk for instability after primary or revision THA and in the treatment of recurrent dislocation. Patients at higher risk of dislocation include patients with neuromuscular diseases, cognitive dysfunction, an American Society of Anesthesiologists score of 3 or more, and all patients older than 75 years with a history of prior Hip Surgery. In addition, the use of DM cups is indicated in revision THA for any cause, primary THA after femoral neck fracture, and primary THA after tumor resection[1].

According to the 2022 Annual Report from the American Joint Replacement Registry (AJRR), the use of dual mobility total hip arthroplasty (THA) in primary Hip Replacement surgeries has shown a significant statistical increase from 2012 to 2021 (p<0.0001). This increase may be attributed to the enhanced stability and reduced dislocation risk offered by large-diameter dual mobility implants. The data also reveals that dual mobility THA is most commonly utilized in patients aged over 90 and those under 50, with the lowest usage frequency observed in the 60-69 age group [2].

Historical indications for dual mobility THA include patients aged over 75, those with a history of hip surgery, individuals with neuromuscular conditions, those with higher Charlson Comorbidity Index scores or American Society of Anesthesiologists (ASA) scores, patients undergoing primary THA for femoral neck fractures, and revision surgeries.

With continuous improvements in prosthesis design, materials, and manufacturing processes, JUST Medical's dual mobility hip prostheses feature a Ti+HA dual-coated acetabular cup, which enhances bone ingrowth. The highly polished inner surface of the metal liner reduces wear particle generation. The narrowed and polished neck with a chamfered edge of the polyethylene liner prevents impingement with the femoral neck, reducing wear rates and extending the prosthesis's lifespan. Consequently, the indications for surgery have expanded to include patients under 60 and those with higher activity levels. Dual mobility hip prostheses are a viable option for patients at a high risk of dislocation due to conditions such as post-stroke sequelae, Parkinson's disease, post-poliomyelitis syndrome, advanced age, or the need for revision surgery.

Indications for Dual Mobility Total Hip Arthroplasty

1. Primary and Complex Primary Hip Replacement:

- Osteoarthritis

- Developmental Dysplasia of the Hip (DDH)

- And other conditions

2. Patients at High Risk of Dislocation:

- Cognitive Impairment (e.g., Alzheimer's Disease)

- Lower Limb Muscle Weakness (e.g., Cerebral Palsy, Parkinson's Disease)

3. Spinal and Lumbar Conditions Affecting the Hip:

- Ankylosing Spondylitis

- Lumbar/Spinal Fusion Surgery

4. Special Activities with High Mobility Demands:

- Yoga Enthusiasts

- Dancers

- Martial Artists

5. Revision Surgery Patients:

- Injury to the Hip Abductor Muscles (External Rotators)

JUST Anti-dislocation Dual Mobility Acetabular System

【References】

[1] De Martino, Ivan & Triantafyllopoulos, Georgios & Sculco, Peter & Sculco, Thomas. (2014). Dual mobility cups in total hip arthroplasty. World Journal of Orthopedics. Volume 5. 180-187.

[2] American Joint Replacement Registry(AJRR) 2022 Annual Report