Total wrist arthroplasty (TWA) is a challenging procedure for wrist joints severely destroyed by rheumatoid arthritis. The most common postoperative complication of TWAs is the loosening of the carpal component. Revision surgeries for failed TWAs can be complicated owing to severe bone loss and concomitant soft-tissue problems. Here, we report a case (68-year-old woman with a history of rheumatoid arthritis for 24 years) of severe aseptic loosening of semi-constrained TWA and its salvage surgery. During the primary arthroplasty procedure, severe instability at the second through fifth carpometacarpal joints was observed and arthrodesis of these joints was required. The radiographs obtained 9 months after surgery showed loosening of the carpal component. Subsequently, she suffered a stroke, resulting in a loss of follow-up, and higher stress was loaded on her upper extremities during standing and walking. In the radiograph taken at her revisit 25 months after the primary surgery, the subsidence of the carpal component progressed and loosening of the radial component was observed. Total wrist arthrodesis was performed using a bulk bone allograft of the femoral head, combined with a penetrating Wrist Fusion Rod®. Rapid bone union was achieved without soft-tissue irritation. We conclude that wrist arthrodesis with a bulk bone allograft combined with an intramedullary nail is a reasonable option for failed total wrist arthroplasty.

The human wrist joint is an elegant mechanism. The wrist allows the positioning and orienting of the hand to the forearm. The computational modeling of the human hand, especially of the wrist joint, can reveal important information about biomechanical mechanisms and provide the basis for its dysfunction and pathologies. For instance, this could be used for therapy planning in total wrist arthroplasty (TWA). In this study, different optimization methods and sensitivity analyses of anatomical parameters for musculoskeletal modeling were presented. Optimization includes finding the best available value of an objective function, including a variety of different types of objective functions. In the simplest case, optimization consists of maximizing or minimizing a function by systematically choosing input values from within an allowed set and computing the value of the function. Optimization techniques are used in many facets, such as the model building of joints or joint systems such as the wrist. The purpose of this study is to show the variability and influence of the included information for modeling, investigating the biomechanical function and load situation of the joint in representative scenarios. These possibilities to take them into account by an optimization and seem essential for the application of computational modeling to joint pathologies.

BACKGROUND: Posttraumatic ulnar carpal translocation is a very rare condition that is caused either by fracture-dislocation injury or by purely ligamentous injury of the wrist. Its prognosis is poor and development of posttraumatic pancarpal wrist joint osteoarthritis is inevitable, and options for treatment are total wrist fusion or total wrist arthroplasty.
METHODS: A 24-year-old male sustained a fracture-related injury in his left wrist that was accompanied with a second ligamentous distorsion-related injury 1 year later in the same wrist. Seven years after first injury, a posttraumatic pancarpal wrist joint osteoarthritis has developed that was caused by posttraumatic ulnar carpal translocation. The patient was treated by total wrist arthroplasty with use of the MaestroTM Wrist Reconstructive System.
RESULTS: With our patient, it is unclear whether posttraumatic ulnar carpal translocation occurred either as result of the first fracture-related injury or as result of the second ligamentous distorsion-related injury or as result of both injuries. The 31-year-old patient could be reemployed completely in his original occupation as a mechanic for big agriculture machines and load his wrist with more than 10 pounds. In order to preserve motion, the patient reported that he would undergo the same total wrist arthroplasty a second time were it necessary.
CONCLUSIONS: We report on a young male receiving total wrist arthroplasty and resulting in good restoration of his high-demand claims in activities of daily living, respectively. However, it cannot be concluded that total wrist arthroplasty is to be preferred generally over total wrist fusion in young patients. Essential prerequisite for this motion-preserving procedure is the compliance of patients.