Ulnar fractures and ligament injuries of the wrist

Sammanfattning: Falling over on an outstretched hand with the wrist extended is a common accident that can cause a multitude of injuries in the wrist. Research has mainly focused on distal radius fractures while injuries of the distal ulna and adjacent ligaments have taken a back seat. If not treated adequately, these injuries may result in ulnar-sided wrist pain, sometimes referred to as the “black box” of hand surgery. The distal radio-ulnar joint (DRUJ) enables  forearm rotation where the radio-carpal unit rotates around the fixed ulna, stabilised most importantly by the triangular fibrocartilage complex (TFCC). Painless rotation and stability of the forearm under load is important for upper limb function. If full function is to be restored after wrist injury, it is important to treat not only injury to the radius but also those to the ulna and TFCC.The aims of this thesis were to evaluate the long-term results of TFCC injury repair, and contribute to our knowledge on fractures of the distal ulna, their epidemiology, radiographic classification and results of treatment.The long-term outcome of 47 patients with a foveal TFCC tear was evaluated by patient-rated wrist evaluation (PRWE) and radiography 20 years after open repair. The median PRWE score was 22.6 (7-48.5), and 34 % had had further surgery after the initial repair, half of these due to recurrence of DRUJ instability. Signs of osteoarthritis were seen in the radiocarpal joint in 17.5 % and in the DRUJ in 34 %. Higher PRWE scores were seen in patients with osteoarthritis or those who had undergone further surgery. Radio-carpal osteoarthritis was less frequently seen in patients who had undergone initial arthroscopy. This study highlights the importance of arthroscopy in identifying associated injuries. Twenty years after foveal TFCC tear repair patient reported outcomes were similar to those of distal radius fractures.Apart from fractures of the styloid process, distal ulna fractures are rare. All distal ulna fractures in the county of Östergötland 2010-2012 were identified. A total of 766 fractures were found (incidence 74/100 000 person-years), the majority of which were fractures of the ulnar styloid process(79%) usually caused by a fall from standing height. Most patients were female (76%), mean age at the time of injury was 63 years and 92 % had a concomitant distal radius fracture. Second after styloid fractures were fractures of the ulnar neck. A retrospective study of 96 patients with 97 fractures of the distal ulna (excluding the styloid) showed that 40 % were treated by internal fixation. The median PRWE score was 15, with significantly worse scores in patients with an internally fixed distal ulna fracture compared to patients not operated. When classifying these fractures according to AO/OTA 2018, transverse extra-articular fractures (2U3A2.3) had a significantly better outcome when not treated surgically, and these probably do not require internal fixation if the distal radius provides stability and alignment. All 97 fractures were classified by three independent observers according to three classification systems: Biyani, AO/OTA 2007, and AO/OTA 2018. Classification was repeated after a minimum of 3 weeks. Reliability and reproducibility were calculated. The reliability was judged as fair for AO/OTA 2007, and moderate for Biyani and AO/OTA 2018. The reproducibility was moderate for all three systems. These results together with the observers´ opinion that Biyani is an easier system to use, leads us to conclude that a slightly modified Biyani-system together with improved radiological techniques that provide more information about the fracture pattern, may well improve accuracy, reliability and reproducibility.A better classification of distal ulna fractures could help us in the evaluation of new and existing treatments as well as providing the information necessary for designing treatment algorithm. After careful consideration, internal fixation is probably the treatment of choice for certain types of fracture, but this needs further investigation.