title: The Role of Dynamic (4D) CT in the Detection of Scapholunate Ligament Injury.
abstract: BackgroundScapholunate (SL) interosseus ligament injuries detected at an early stage could allow the surgeon to prevent progression through the spectrum of injury that leads to instability, and eventually osteoarthritis. We contend that early instability following injury can be detected by visualizing the relative motions and distances between the involved carpal bones (scaphoid and lunate) during wrist movement in vivo. The purpose of this study is to demonstrate the utility of dynamic CT (i.e., 4DCT) in diagnosing SL interosseus ligament injuries in two patients with clinical suspicion of SL interosseus ligament injury during flexion-extension (FE), radial-ulnar (RU) deviation, and dart thrower's (DT) motions.Case Description4DCT images obtained from two individual cases were analyzed to assess the proximity between the scaphoid and lunate during wrist motion using standard image processing techniques. Proximity maps representing the distances between the scaphoid and lunate bones during each phase of wrist motion were determined. These maps provide insight into the severity of diastasis (large separation) and location of diastasis at the SL joint. The patients' proximity maps indicated dorsal diastasis and subtle uniform diastasis.Literature ReviewComplex musculoskeletal abnormalities, such as wrist joint instabilities, elude diagnosis during 2D fluoroscopy due to the 3D geometry of the anatomy and the inherent 3D nature of the bony kinematics. Even the most recent advances with MR arthrography lack good correlation with wrist arthroscopy. Wrist arthroscopy remains the gold standard for diagnosis to assess for intercarpal laxity. However, arthroscopy is an invasive procedure subjecting patients to the risk of infection, nerve injury, pain, and stiffness.Clinical Relevance4DCT allows noninvasive characterization of where ligament injuries likely occur; this may allow for a more selective surgical treatment directed at the specific location of the tear.
authors: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors: Sanjeev
authors: S
authors: Kakar
authors: Rehabilitation Medicine Research Center, Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota.
authors: Ryan E
authors: RE
authors: Breighner
authors: Department of Radiology, Mayo Clinic, Rochester, Minnesota.
authors: Shuai
authors: S
authors: Leng
authors: Department of Radiology, Mayo Clinic, Rochester, Minnesota.
authors: Cynthia H
authors: CH
authors: McCollough
authors: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors: Steven L
authors: SL
authors: Moran
authors: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors: Richard A
authors: RA
authors: Berger
authors: Rehabilitation Medicine Research Center, Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota.
authors: Kristin D
authors: KD
authors: Zhao
keywords: 4DCT; computed tomography; scapholunate interosseus ligament