The M.A.S.® socket design is an evolution--and perhaps even a "revolution"--in the development of ischial containment (IC) socket concepts. Since 1999, when Marlo Ortiz Vazquez del Mercado, Ortiz Internacional, Jalisco, Mexico, first unveiled his new design, it has continued to arouse interest throughout the O&P worldwide community. Recently the design was featured in the Thranhardt lecture series during the American Academy of Orthotists & Prosthetists 2004 Annual Meeting and Scientific Symposium.

The new design provides several clinical benefits: patients can sit more comfortably; there is no plastic beneath the gluteus; the prosthesis is easier to don; patients enjoy full range of motion, better functional gait--and important to patients and family members too--much better cosmesis. Seeing a video of patients walking, sitting, and demonstrating the range of motion possible is truly amazing.

What is the M.A.S. Socket

Ortiz describes his design: "It is very important to consider the angle of the ischial ramus. The ischial tuberosity and part of the ramus as well as the medial aspect of the ramus are encapsulated within the medial aspect of the socket brim." Generally, the medial wall is lowered anteriorly to avoid pressure on the ascending ramus; effectively ischioramal weight-bearing eliminates the need for gluteal support, so those tissues can be excluded from the socket, he explained.

In the conventional design, posterior trim lines include part of the gluteus maximus. In the M.A.S. design, the height of the posterior wall has been lowered to the gluteal fold, so the entire muscle belly can be free of the socket. "This will not only improve cosmesis but with this configuration, we have found that ischial tuberosity and part of the ischial ramus are encapsulated more effectively with no restriction in hip movement," Ortiz said.