A novel technique to understand instability of scaphoid fractures

Shai Luria, M.D.

A scaphoid fracture is a break of one of the small bones of the wrist. The wrist is perhaps the most complicated joint in the body. This fracture occurs generally among young and middle-aged adults typically between the ages of 15-60 years and accounts for 50–80% of carpal injuries. At the Hadassah Emergency Unit alone, 20% of trauma patients are due to wrist or hand injuries. The difficulty in diagnosing such fractures using radiographic studies or clinical exam alone can sometimes allow subtle scaphoid fractures to go undiagnosed. A delayed diagnosis can lead to a variety of adverse outcomes including non-union (up to 88%) or delayed union, arthritis and a limited range of wrist motion. In addition, another common complication of a scaphoid fracture is avascular necrosis which is interruption of the blood supply to the bone. Without blood, the bone tissue dies and the bone collapses. Whether treatment is surgical or nonsurgical, these injuries require prolonged periods of immobilization and are commonly missed (may be mistaken for a wrist sprain) resulting in further disability. Thus, a correct diagnosis and prompt treatment is based on fracture stability (high chance of healing) or instability (with complications outline above).

Most surgeons rely primarily on using x-rays and CT scans to accurately visualize the fracture. However, the complex shape of the scaphoid hampers the evaluation of fracture location, morphology and degree of fragment displacement which can lead to suboptimal treatment. Dr. Shai Luria from the Department of Orthopedic Surgery is actively investigating this challenging and complex situation by using patient-specific 3D computer models which in his own words “has changed our understanding of these common injuries.” Using this advance tool, Dr. Luria is better able to identify the characteristics of scaphoid fractures and their location in relation with anatomic landmarks and in correlation with fracture displacement as a sign of instability. Moreover, Dr. Luria can also examine the effect of mid-carpal joint anatomy which may have a crucial role in fracture stability. This 3D computer model requires the cooperation between the clinician and a computer engineer including a large database of patients. The precision provided by this new technology can allow the surgeon to accurately visualize the fracture, degree of displacement and fix the fracture correctly for proper union rather than operating in spite of the shape and characteristics of the fracture.
Dr. Shai Luria spoke very enthusiastically about the use of the patient-specific 3D computer model since it allows a superior understanding of the biomechanics of scaphoid fractures, the ability to isolate the unstable injuries and plan a superior and accurate approach to the surgical care. “This innovative method can prevent the development of devastating complications and will allow young people to return faster to activity” Dr. Luria said.