Comparison of volar locking plates with external fixation and K-wires in arthroscopically assisted intra-articular distal radius fracture fixation Distal radius fractures (DRF) are one of the most common bone injuries presented in emergency rooms and varies from 20 to 30% of all fractures. (Ilyas and Jupiter, 2007; MacIntyre and Dewan, 2016). These fractures are presented in all age groups and both genders, but there is a typical bimodal distribution – more often young males with complicated injuries and older females with DRF and osteoporotic changes are observed. Most of distal radius fractures are simple, extraarticular, non-dislocated or minimally dislocated ones and can be treated conservatively. But up to 30–40% of fractures nowadays are intra-articular ones (Koo et al., 2013; Sander et al., 2018), and require surgical restoration of the articular surfaces, to achieve the best possible functional result in a case of an adequate rehabilitation. Until the 1980`s, criteria for successful treatment of the articular DRF`s had not been established and demonstrated. Treatment of the complex DRF`s was not performed adequately, in modern understanding, because of the absence of implants for variable and multiple fragment fixation and also there was a perception that the successful treatment of such fractures is questionable. In 1986 J. L. Knirk and J. Jupiter published the iconic paper about the treatment results of the articular DRF in young adults and defined the maximum permissible articular gaps and step-offs to prevent or reduce the risk of posttraumatic deformative osteoarthrosis. They concluded that 91% of articular fractures with step-off more than 1 mm after the reposition and 100% of fractures with step-off more than 2 mm are complicated by deformative osteoarthrosis (Knirk and Jupiter, 1986). New implants and methods of the DRF treatment were developed during the next decades. Nowadays there are two main principles of the surgical treatment of DRF – open reduction and internal fixation with volar locking plate, which provides maximum support of the subchondral bone and a stable fixation. And the second one – closed, minimally invasive reposition under the fluoroscope control and stabilization of the fragments with K-wires and external fixator, mostly in cases of fractures where volar locking plates cannot be used because of the fracture patterns. There are many articles which claim that superior outcomes are achieved as a result of plating (Esposito et al., 2013; Franceschi et al., 2015; Richard et al., 2011; Wilcke et al., 2011; Williksen et al., 2013; Wright et al., 2005; Xie et al., 2013) and others which claim that external fixation and K-wire are superior (Kapoor et al., 2000) (Pino et al., 2011). The conclusions of published meta-analysis studies on this topic also are controversial – Walenkamp et al. in 2013 published results of the superiority of the volar locking plate (Walenkamp et al., 2013), but Margaliot et al. in meta-analysis study published in 2005 did no find statistically significant differences between these two methods(Margaliot et al., 2005). Although the first wrist artrhroscopy was performed in 1979, the rapid development of this method started only in 1986 when T. L. Whipple, after several anatomical studies, described the portal map for safe wrist artrhroscopy (Whipple et al., 1986). Since this was published, numerous studies have been published which confirm the superiority of arthroscopic reduction over the only fluoroscopically controlled surgeries (Abe and Fujii, 2017; Doi et al., 1999; Freeland and Geissler, 2000; Lutsky et al., 2008; Ono et al., 2012; Ruch and Papadonikolakis, 2006; Varitimidis et al., 2008). Arthroscopic surgery of the wrist in Latvia was introduced in the Centre of Plastic, Reconstructive and Microsurgery in 2009. In 2010 the first arthroscopically assisted distal radius fracture surgery was performed. This method of treatment allows to verify the precise position of the fragments, evaluate the joint surface, perform precise fixation and detect additional soft tissue injuries with minimal invasiveness (Chen et al., 2002; Guofen et al., 2005; Kamano et al., 2005; Lutsky et al., 2008; Ruch et al., 2004). So far there is a lack of studies regarding the comparison of different arthroscopically assisted treatment methods of DRF`s in English speaking data bases and medical literature. This study presents a detailed analysis of the literature about the anatomy, morphology, biomechanics and treatment methods of the articular DRF`s and reasons for them, as well as a prospective comparison of subjective and objective outcomes, recorded 1, 3, 6 and 12 months after the primary surgery, of the two methods of fixation, both in combination with arthroscopically assisted reduction of intra-articular fragments. This was a prospective cohort study, where patients were allocated into two groups using an alternate allocation method, the first patient undergoing surgery with VLP, the second one with an external fixator and K-wires, the third one with VLP an so on. This method of the randomization was chosen to achieve the same and sufficient number of patients in both groups as quick as possible. During the 2-year study period, 74 surgeries were performed (38 in VLP group and 36 in EF group). Four patients in VLP group and six patients in EF group did not returned for scheduled follow-up and thus were excluded. Consequently only 34 patients from VLP group and 30 patients from EF group were included in the final data assessment. The results of treatment were assessed with X-ray examinations postero-anterior position in a 10° tilted-view and lateral position in a 20° tilted view, subjective evaluation using the Patient-Rated Wrist Evaluation (PRWE) score, Modern Activity Subjective Survey of 2007 (MASS07) score, and subjective and objective evaluation using the Gartland and Werley score. Grip / pinch / tripod-pinch strength and range of motion were also measured. The clinical parameters as well as subjective scores improved evenly during the 12 months following surgery, showing a small superiority in figures for the patients of VLP group. Number of complications was small and equal in both groups, but these ones in EF group were medically more serious than complications in the VLP group. The incidence of additional reduction of fracture fragments at arthroscopy in both groups was higher than found in literature. Alternate allocation method, which was chosen as a method of randomization in some cases made it difficult to fix fragments optimally and limited the surgeon to adapt the technique according to the complexity of the fracture type.