Peter S. Johnston M.D. Physician


Peter Johnston, M.D. specializes in orthopaedic surgery and rehabilitation at the Southern Maryland Orthopaedic & Sports Medicine Center division in Leonardtown, Maryland.  

He is a board-certified shoulder and elbow specialist who is committed to providing compassionate, patient-centric care for shoulder and elbow problems. He manages complex problems of the shoulder with both open and arthroscopic methods including arthritis, rotator cuff tears, instability, and fractures with cutting edge technology in an evidence-based fashion. Further, Dr. Johnston also focuses on conditions of the elbow including trauma, arthritis, and instability including Tommy John (UCL reconstruction) surgery. He is a member of American Shoulder Elbow Surgeons.

A native of Michigan, he received his Bachelor of Science degree in Neurosciences at the University of Michigan. He completed his medical training at Wayne State University in Detroit, MI where he graduated with honors. Dr. Johnston completed his orthopaedic internship at the Detroit Medical Center/Wayne State University School of Medicine and then moved to Chapel Hill, NC where he completed his formal orthopaedic surgery training at the University of North Carolina. At UNC, he participated in sports coverage and care of the Division I athletes and received honors as nominated by his co-residents and mentors.

After completing his residency, Dr. Johnston spent a year as a fellow at the prestigious Rothman Institute at Thomas Jefferson University in Philadelphia, PA sub-specializing in shoulder and elbow surgery. While at the Rothman Institute he trained with some of the most renowned shoulder and elbow surgeons in the country, including Drs. Gerald Williams, Mark Lazarus, Matthew Ramsey, John Fenlin and Charles Getz. This training offered a vast exposure and education in all facets of managing shoulder and elbow problems from a standard rotator cuff repair to a complex revision shoulder reconstruction.  

To further his shoulder training, Dr. Johnston spent time in Lyon, France with some of the world leaders in shoulder replacement, particularly reverse total shoulder arthroplasty. While there, he spent time with Giles Walch, who is considered a world leader and innovator of shoulder replacement.  

He joined the Centers for Advanced Orthopaedics, Southern Maryland Orthopaedics and Sports Medicine Division in September 2011. Dr. Johnston brought an expertise in complex surgery of shoulder and elbow conditions to the region and enhanced shoulder and elbow care in the community.  He has provided premier care for local minor league baseball players and numerous collegiate and aspiring collegiate athletes. He performed the first reverse shoulder replacement locally.

He continues to pursue his research interests with recent peer reviewed publications, book chapters and presentations on the management of proximal humerus and clavicle fractures, treatment of massive rotator cuff tears, shoulder replacement with glenoid bone loss, and the management of shoulder arthritis in younger patients. As a primary Investigator of a FDA Investigational Device Exemption (IDE) trial, he evaluated a novel implant bearing surface for the treatment of arthritis with a shoulder hemiarthroplasty. Currently, Dr. Johnston and his team are involved in several novel research projects both independently and collaborating with other institutions. 

Dr. Johnston has continued to pursue an academic career as an assistant professor at Georgetown University Department of Orthopaedic Surgery providing resident education in the clinic and operating room. He has participated in numerous regional and national courses educating shoulder and elbow fellows and surgeons.

In addition to his clinical practice, Dr. Johnston is involved in designing novel shoulder replacement components with the goal of improving replacement longevity for patients to enjoy a fully functional, pain free quality of life. He has been involved with implant design through the early conceptual stages to bringing the product to the operating room for actual patient use. 

Dr. Johnston and his wife Tiffani, who was born in Southern Maryland, have three children: Mattingly Jane, Chandler, and Shay. His interests outside of work include time spent with family, boating, golf, fishing, hunting, and skiing.

Areas Of Expertise

Orthopaedic Surgery

Arthroscopic Methods of Management: Arthritis, Instability, Joint Contracture, Soft Tissue Repair of the Shoulder and Elbow

Total and Partial Joint Replacement: Arthritis, Fractures and Tears of the Shoulder and Elbow

Care of the Young and Aging Athlete


Shoulder and Elbow Surgery

Medical Degree

Wayne State University School of Medicine; Detroit, MI


University of North Carolina Department of Orthopaedic Surgery; Chapel Hill, NC


Thomas Jefferson University/ Rothman Institute, shoulder and elbow surgery; Philadelphia, PA


American Board of Orthopaedic Surgery

Professional Associations

MidAtlantic Shoulder and Elbow Society

Major Accomplishments

William C. Patton Chief Resident Teaching Excellence

Resident of the Year at WakeMed Hospitals, University of North Carolina

Numerous peer reviewed publications, book chapters, and podium presentations

Hospital Affiliations

MedStar St. Mary’s Hospital

Affiliated Surgery Centers

Leonardtown Surgery Center