English

Abstract

Introduction Joint distraction is a surgical technique that has been used to treat a variety of joint diseases, including degenerative arthropathies such as osteoarthritis and chondrolysis. In this critical review, we described the effect of joint distraction treatment. Materials and methods The systematic search was specifically aimed at preclinical and clinical publications about joint distraction in subjects with degenerative cartilage damage. After literature screening, 30 publications were included, reporting on the treatment of degenerative arthropathies of hip, ankle and knee. Results Joint distraction has been found to reduce pain and improve joint function in both preclinical and clinical studies. Furthermore, structural tissue repair is shown. Although well documented, the clinical studies are of limited quality. Only two randomized controlled trials, both on ankle joint distraction and both with limited number of patients, were included. Furthermore, most studies have modest follow-up periods of 1 and 2 years. Conclusion The results on structural repair induced by this treatment may lead to a better understanding. of the regeneration capacity of joint tissues in degenerative joint diseases. Introduction Osteoarthritis (OA) is a degenerative joint disease mainly characterized by cartilage loss. This leads to a decreased joint space width (JSW), frequently accompanied by mild synovial tissue inflammation and subchondral bone changes, such as sclerosis, subchondral cysts and osteophyte formation1. In a more advanced state of the disease, most patients experience pain and loss of function. Common surgical treatment in this end stage of disease is an arthrodesis or joint replacement. For younger physically active patients (<65 years), joint replacement is not the ultimate solution due to a limited lifespan. As such, there is a need for strategies that preserve the joint and treatments aiming at cartilage tissue repair. One of the joint-preserving treatments available is joint distraction, enabling intrinsic joint tissue repair supposedly due to regaining proper biochemical and biomechanical joint homeostasis. Joint distraction is a surgical technique in which two joint surfaces are fully separated to a certain extent by an external fixator frame for a limited period of time. During this separation, further wear and tear of the affected joint is preserved by full mechanical unloading2. The general opinion is that the osteoarthritic joint cannot repair itself; however, repair of joint tissues in addition to clinical benefit has been claimed by joint distraction in several preclinical and clinical studies. These studies demonstrate that under specific circumstances intrinsic cartilage repair is actually possible. In this crtitical review, we describe data from preand clinical studies on joint distraction, focussing on the larger joints, in relation to tissue repair and clinical benefit. Materials and methods For joint distraction, also called arthrodiatasis that consists of the Greek words arthro (joint), dia (through) and tasis (to stretch out), a systematic approach was used. PubMed, EMBASE and Cochrane libraries were searched for the words ‘distraction OR arthrodia(s)tasis AND joint OR articul*’ (December 2012). Titles and abstracts were screened for inclusion and exclusion criteria as formulated in the flow chart ( Figure 1). Full text screening designated publications focussing on restoration of degenerative joint damage with temporarily used external fixation devices in animal in vivo and clinical studies. Excluded were analyses without original data, studies in patients with intra-articular fractures or soft-tissue joint contractures, treatments with intraoperative use of distraction without the purpose of tissue regeneration, and treatments with permanent implantation of distraction devices. Screening the reference lists of relevant publications identified additional papers. Results Joint repair by joint distraction treatment in preclinical animal models After screening, seven preclinical animal studies were identified ( Table 1). Six of them had the knee as joint target and one study described joint distraction in a spine model3. It must be considered that the animal models described use traumainduced cartilage (and bone) damage * Corresponding author Email: S.Mastbergen@umcutrecht.nl †Authors contributed equally. 1 Rheumatology and Clinical Immunology, University Medical Center Utrecht, the Netherlands 2 Limb Reconstruction Center, Department of Orthopedics, Maartenskliniek Woerden, the Netherlands 3 Limb Reconstruction Center, Department of Orthopedics, University Medical Center Utrecht, the Netherlands