LASER HAEM Version 1.0
Research type
Research Study
Full title
Mechanism of action study to evaluate the effect of Leeds Ankle Stabilising Enhanced Rocker (LASER) boot in haemophilia haemarthrosis ankle joint arthritis.
IRAS ID
262181
Contact name
Faculty Research Ethics and Governance Administrator,
Contact email
Sponsor organisation
University of Leeds
Duration of Study in the UK
0 years, 11 months, 30 days
Research summary
Haemophilia impairs bleeding control because of an absence of clotting factor VIII (haemophilia A) or factor IX (haemophilia B) resulting in bleeding into muscles and joints. Although treatment with artificial clotting factor has some effect on frequency of bleeds, most patients still experience ongoing spontaneous and traumatic bleeds in joints. Prolonged exposure of joint structures to blood leads to cartilage, structural and functional damage, ultimately resulting in pain and disability. Damage also leads to changes in joint function furthering the risk of subsequent mechanical joint and soft tissue haemorrhage. Ultimately, this vicious cycle results in cumulative and irreversible damage to joints with severe reduction in mobility. The introduction of clotting factor substitution, both prophylactically and on-demand, has dramatically improved life expectancy and quality of life in patients with haemophilia. The paradigm shift from treating a bleeding episode, to prevention with regular replacement therapy (prophylaxis) has seen a reduction in bleeding frequency. Since the introduction of clotting factor, the most common site for musculoskeletal bleeding has also changed from the knee to the tibiotalar (ankle) joint. Bleeding into the ankle joint is now estimated to account for 20% of all haemophilia-related bleeds in the UK. Despite this, little has been reported on target none-pharmacological treatments such as footwear.
Modified footwear is used to improve patient mobility and function in a number of conditions associated with impaired walking including rheumatoid arthritis (RA ) and orthopaedic deformities (Hutchins, Bowker et al. 2009). During walking, as the foot makes contact with the ground, the foot and ankle normally act as a fulcrum to allow forward progression of the limb; a process referred to as the ‘anatomical rocker’ (Kirtley 2006). In haemarthrosis of the ankle, gait changes have been identified at all phases of the anatomical rocker and result in significant reduction in motion, change in ankle forces and reduced gait efficiency (Lobet, Hermans et al. 2012). Where the normal anatomical rocker mechanism is impeded, rocker-soled footwear can be used to perform the function of the fulcrum and used in the management of conditions such as diabetes and RA, to prevent ulceration and improve mobility (Nigg, Hintzen et al. 2006, Forghany, Nester et al. 2013).
The ‘rocker’ sole and ‘solid-ankle cushion heel’ (SACH) are the most common footwear modifications prescribed for external shoe modification (Wu, Rosenbaum et al. 2004). The SACH heel of the shoe is thought to create a pseudo-plantarflexion moment that prepares the foot to allow ‘roll over’ of the body’s mass and was traditionally used in prosthetic feet (Wu, Rosenbaum et al. 2004). In the Leeds comprehensive care centre (CCC), a modified version of the SACH uses a lightweight elastomer or expanded ethylene-vinyl acetate (EVA) which has greater shock absorbency than traditional SACH materials such as ethylene vinyl acetate (Bonnet, Adde et al. 2014). It is hypothesised that an astroshock SACH provides a stable SACH heel, improving lower limb mechanical advantage and facilitating forward progression of the body’s mass. The Leeds Ankle Stabilising Enhanced Rocker (LASER) boot is based upon a military boot with a rocker profile and a modified SACH and has been used clinically to treat ankle pathology in patients with haemophilia for 11 years. In the Leeds CCC, audit data obtained from eight adults using the LASER boot indicated an improvement in patient reported pain and disability scores by 18.5%, and a reduced incidence of ankle bleeds from 11.4 to 2.2 per patient over a 12 month period. To establish the mechanism of action of the LASER boot a 3d gait analysis study was undertaken in health males as part of the CIs PhD fellowship. The individual and combined components of the boot (military boot, SACH heel, rocker sole etc) were tested to understand the effect of the boot and refine its design prior to testing in a haemophilia population. Now that mechanism of action has been established, the LASER boot will be tested in a haemophilia cohort prior to a full multicentre randomised control trial.REC name
London - Surrey Borders Research Ethics Committee
REC reference
19/LO/1640
Date of REC Opinion
25 Nov 2019
REC opinion
Further Information Favourable Opinion