Clinical Research

Orthopaedic clinical research

Advancing the musculoskeletal field using multidisciplinary, evidence-based research

The Department of Orthopaedic Surgery continues to pioneer major advances in the care and treatment of musculoskeletal injuries and disorders.

Total Joint Arthroplasty (TJA)

The arthroplasty group has developed a total joint replacement registry to study their patients on a prospective basis. The faculty (Paul Gilbert, MD, Nathanael Heckmann, MD, Jay Lieberman, MD, Donald Longjohn, MD, Daniel Oakes, MD) are keenly interested in improving outcomes for total joint arthroplasty patients and to use advanced technology to achieve this goal. Major areas of research interest include:

  • Outcomes and complications associated with dual mobility prosthesis
  • The influence of spinopelvic mobility on dislocations after THA
  • Prosthetic selection and the influence on dislocation after THA
  • Improving outcomes associated with total knee and hip arthroplasty
  • Outcomes associated with robotic unicompartmental knee arthroplasty

Other areas of research include:

Dr.Nathanael Heckmann’s research focuses on outcomes following primary and revision total hip and total knee arthroplasty. In particular, his research focuses on understanding the interrelationship between degenerative diseases of the spine and hip as well as improving outcomes following the surgical treatment of infected hip and knee replacements.

Dr. Jay Lieberman’s clinical research is focused on improving outcomes after total hip and knee arthroplasty and with a special emphasis on osteonecrosis of the hip and venous thromboembolism prophylaxis following joint replacement surgery. He is also a pioneer in the development of regional gene therapy strategies to enhance bone repair for complex fractures and revision total joint arthroplasty patients. Dr. Lieberman has published more than 250 peer reviewed studies and reviews.

Dr.Daniel Oakes has a particular interest in complex and revision hip and knee arthroplasty. His research is focused on the augmentation of large cavitary osseous defects in revision hip arthroplasty patients. He is also interested in robotic-assisted knee replacement surgery and understanding how these novel technologies may improve future patient outcomes.


Dr. Gary and Dr. Patterson will leverage the strengths of Keck Medicine of USC and Los Angeles General Medical Center in addition to their collaboration with the Major Extremity Trauma and Rehabilitation Consortium (METRC) to generate high-level published evidence that guides the optimal care of injured patients.

Joshua L. Gary, MD focuses his clinical research on surgical treatments and techniques to improve patient outcomes after pelvic, acetabulum, and extremity trauma.  His award winning research includes multiple “Highlight Papers” from the Annual Meeting of the Orthopaedic Trauma Association, numerous publications and presentations at national and international meetings.  He has been instrumental in running federally funded multicenter clinical trials for more than a decade to elevate the quality of research in orthopaedic trauma.  He serves on the Executive and Publications Committees within the Major Extremity Trauma and Rehabilitation Consortium (METRC) and is the Principle Investigator of the EMS-BinD study, a $4 million award from the U.S. Department of Defense to evaluate the effect of pelvic binders on shock for pelvic ring disruptions.

Joseph T. Patterson, MD focuses his clinical research on leveraging technology to level disparities and improve outcomes after pelvic and limb trauma. He is translating personal device technology to improve access to fracture care and aftercare. He is adapting 3D navigation and modeling tools to improve the safety of pelvis fracture surgery and limb deformity correction. He uses large administrative databases to analyze patients with orthopaedic problems after trauma.

Hand, Upper Extremity, and Microvascular Surgery

The division of Hand, Upper Extremity, and Microvascular surgery is actively engaged in multiple areas of research to continue to improve patient care. Investigators include Milan Stevanovic, MD, PhD, Rachel Lefebvre, MD, and Luke Nicholson, MD. Topics of ongoing research include:

  • Vascularity and viability of free functional tissue transfer in complex microvascular reconstructive surgery
  • Patient reported outcomes following operative management of distal radius fractures with an emphasis on decreasing the time to recovery following surgery
  • Virtual patient care and optimizing physician-patient communication
  • Vascularity of peripheral nerves in the setting of peripheral nerve compression
  • Biomechanical evaluation of scaphoid nonunion fixation constructs
  • Use of wide awake, local-only anesthesia in upper extremity surgery
  • Wrist-spanning fixation in the management of radiocarpal fracture dislocations


The Spine clinical research team includes Jeffrey C. Wang, MD, Raymond Hah, MD, Mark Spoonamore, MD, Gene Tekmyster, DO, Christopher Ornelas, MD and Zorica Buser, PhD.

The Spine Center research focuses on establishing innovative approaches for the treatment of spinal disorders including minimally invasive surgeries, complex deformities, disc replacement and non-surgical approaches.

Ongoing research studies include:

  • Multi-disciplinary research projects include single center and multi-center studies and the evaluation of data from multiple insurance databases.
  • The use of Kinematic MRI allows investigators to evaluate degenerative changes that are only visible with loading and bending of the spine. This allows the assessment of the spine in neutral, flexion and extension positions.
  • Research on costs of spine treatments and quality of care improvement
  • The utilization of predictive analytics assessing the influence of modifiable risk factors on the outcomes of spine surgery.

The USC Sports Medicine Research Program

At USC, we believe that the world-class care is not only driven by clinical excellence, but also by a commitment to furthering our understanding of musculoskeletal disease. Our sports medicine surgeons work closely with a multidisciplinary research team to develop novel approaches for the treatment and prevention of common sports-related injuries. This work includes:

  • The prospective study of the outcomes of shoulder, hip, elbow and knee surgery procedures
  • Clinical trials to investigate cutting edge treatments for sports medicine injuries and osteoarthritis
  • Biomechanical studies to model the effects of surgery on joint function
  • Basic science studies focused investigating the basic cellular mechanisms of tissue healing and developing treatments for muscle and cartilage injury

Specific areas of research include:

Seth Gamradt, MD, an expert in shoulder, knee and elbow surgery studies the effects of Vitamin D deficiency on NCAA athlete well-being as well as the effects of specific injuries and surgical intervention on the collegiate athlete’s ability to return to play.

George F. “Rick” Hatch, MD, works to find new ways to prepare a patient’s body for the severe stress of surgery and improve recovery. He is leading a clinical trial to use nutritional and testosterone supplementation to create an environment that promotes healing after surgeries such as rotator cuff repair of the shoulder and ACL reconstruction of the knee. Dr. Hatch is an expert in treating complex knee and shoulder injuries, with a specific interest in the study and treatment of multiligamentous knee injuries (or knee dislocations) and severe cartilage injuries. He studies the optimal techniques for reconstructing complex knee and shoulder injuries in order to restore strength and function as well as prevent reinjury.

Reza Omid, MD, is an expert in treating all shoulder and elbow conditions and is currently working to improve treatment options. He is currently developing new surgical techniques for irreparable rotator cuff tears by investigating variations of tendon transfers around the shoulder, as well as the development of a novel vascularized option to supplement current reconstructive procedures.

Frank Petrigliano, MD, a shoulder, knee and elbow specialist oversees a basic science lab that is focused on the study of muscle atrophy and degeneration following large rotator cuff tears.  Following rotator cuff repair, muscle atrophy and fibrosis may result in persistent weakness and increase the risk of repair failure. Consequently, his team is studying cutting-edge approaches to improve rotator cuff function via the delivery of stem cells that are specialized to restore muscle after chronic injury. Dr. Petrigliano also works in close collaboration with Dr. Denis Evseenko at USC developing small molecule and stem cell-based therapies to treat osteoarthritis. The goal of their work is to provide novel treatments that improve function and decrease the risk of arthritis after knee and shoulder injury.

Alex Weber, MD, a shoulder, hip, knee and elbow expert is working with researchers in kinesiology to study the biomechanical effects of femoroacetabular hip impingement on lower extremity kinematics before and after hip arthroscopy.  Dr. Weber also has an interest in the prospective outcomes of shoulder, hip and knee surgery.

Collectively, our team of sports medicine physicians and researchers are advancing novel therapeutics and surgical techniques to improve the care of patients of all ages with athletic injuries.  Our goal is to return our patients to their active lifestyles by applying state-of-the art technology developed right here at USC.

Clinical Research Facilities

The department’s faculty, fellows, residents and students have access to a broad and diverse patient population throughout Los Angeles County. We conduct a variety of clinical research projects in tandem with patient care at five primary facilities:

Keck Hospital of USC and satellites (Beverly Hills, Glendale, El Segundo)

Children’s Hospital Los Angeles

Los Angeles General Medical Center

Rancho Los Amigos National Rehabilitation Center

The department also has basic science research lab space at the USC Norris Comprehensive Cancer Center and Hospital, located on the USC Health Sciences Campus.