BIOMECHANICS AND ORTHOPAEDIC INTERVENTIONS
The institute continues to kindly support our research ideas both financially and by access to the Research Department and Keele University staff. The registrars involved in the research all work hard in full time jobs and the majority of their research is done in their own time. The Research Department headed by Teresa Jones and staff from Keele University offer great support in study design, day to day running of trials, statistical analysis of the results and publishing them.
Greater trochanteric pain syndrome: a randomised trial comparing extracorporeal shock wave versus standard treatment
Funding by Orthopaedic Institute Ltd
Mr Robin Banerjee (Chief Investigator), Mr Ben Burston, Mr Simon Lewthwaite (Principal Invesigators), Miss Catriona Heaver (Specialist Registrar), Dr Andrea Bailey (Senior Physiotherapist), Rajesh Gilla, Tessa Rowlands, Jean Denton (Physiotherapists), Lisa Burgess (Trial Administrator) and Dr Jan Herman Kuiper (Statistician)
Greater trochanteric pain syndrome (GTPS) is a common problem affecting between 1.8 and 5.6 patients per 1000 per year. It is more frequent in women and between the ages of 40 and 60. GTPS is characterised by pain and tenderness over the greater trochanter, the bony bump on the outside of the hip, or by pain when lying on the hip, and is due to a tendon disease (tendinopathy) of a deep-lying tendon. We have long used radial shockwave for the treatment of more superficial tendinopathies such as patellar tendonitis, Achilles tendonitis and plantar fasciitis. Unfortunately it was not as successful in the treatment of GTPS because the inflamed tissues are deeper and radial shockwaves dissipate very quickly into the surrounding superficial tissues. A new kind of shockwave therapy, focused shockwave, was brought to our attention by a company called Impact Medical at a course in Cheshire nearly four years ago. The company kindly donated the machine and all consumables to us for a study and Kevin Jones trained all our staff involved into its safe and effective usage. Focused shockwave uses a slightly different delivery method, concentrating the shockwaves to deeper areas as one would need to treat GTPS (Figure 1). NICE have been looking at it as a potential treatment for GTPS but stated there should be more clinical trials into its effectiveness, so that is what we did!
Figure 1. Equipment to produce focused shockwaves (left) and standard shockwaves (right), together with the shockwave patterns.
We performed an adequately powered single-blinded, randomised prospective trial comparing the standard treatment of ultrasound guided steroid injections to focused shockwave alongside a carefully designed physiotherapy protocol. The study was designed in 2014, started in September 2015 and since then we recruited 95 patients. The final patient was assessed in April 2018, after which Catriona Heaver presented the statistical analyses of the trial results at the 2018 Research Day. These analyses clearly show that focused shockwave is better than injections: it gave significantly better results for all of our outcome measures including pain, function and quality of life scores as well as improvement in clinical signs and the patient’s own subjective assessment of their symptoms. We are now in negotiations with CCG’s to offer this treatment modality to our patients. The major bonus is that it can be carried out safely and effectively in an outpatient setting and delivered by physiotherapy teams without the need for invasive injections.
For her presentation at the 2018 Research Day, Catriona received the coveted Professor’s Medal. She is currently writing up the study for presentation at the BOA and publication in a peer-reviewed journal.
Optimal positioning of memory staples to maximise stability and stiffness of fixation following toe fusion operations
Miss Catriona Heaver, Mr Namdi Obi, Mr Daniel Goldbloom (Senior Trainees), Mr Nilesh Makwana (Consultant Orthopaedic Surgeon) and Dr Jan Herman Kuiper (Senior Lecturer in Biomechanics)
Funded by the Orthopaedic Institute Ltd
A fusion of the first metatarsophalangeal or MTP joint (the big joint of the big toe) is one of the most common procedures performed in foot and ankle surgery. Staples are used to maintain position and compression of the joint while fusion occurs. Most surgeons use two staples to achieve this aim but no-one quite knows how best to position the staples. We therefore decided to do an experiment to find this out. The aim of the study was to establish whether the position of the staples made any difference to the strength and stiffness of the constructs.
For the experiment we used composite Sawbone models, which were “prepared for fusion” using reamers and then placed into a jig to standardise the position of the joint. Nine potential combinations of staple placements were assessed for stability (Figure 2). While the staples were being inserted sensors were used to detect any change in joint position. Each construct was then placed in our Universal Testing Machine to assess the strength of the construct).
Figure 2: Potential positions for the two staples to fix fused metatarsal joints
Top row: top view; bottom row: side view
Our results showed that the position of the dorsal (top) staple has no effect on the strength of the construct. The medial staple; if placed in an inferior (low) position increases the strength of the construct significantly. However, when the same construct was placed under load to cause a certain amount of angulation, a larger amount of permanent deformation occurred, in other words the construct was less stable. Finding the optimal position will therefore involve a compromise between strength and stability. Further study will be required to determine whether staple position has any effect on clinical outcomes.
The influence of lag screws on the stability of distal fibula oblique fractures fixation using one-third tubular plate
Mr Gopikanthan Manoharan, Mr Rohit Singh (Trainees), Prof Len Nokes (Cardiff University) and Dr Jan Herman Kuiper
Funded by Cardiff University
Ankle fractures make up around 9% of all fractures. The commonest type of ankle fractures is an oblique fracture of the distal fibula and involves the lateral and medial malleolus. Most of these fractures are fixed using one-third tubular plates with a lag screw or a dynamic compression plate. It is not known whether this screw is needed. We therefore decided to do a laboratory study in order to find out (1) if the use of a screw made the third tubular plate fixation stronger or stiffer, and (2) how the fixation strength and stiffness of the third tubular plate compared to the compression plate.
This study was a lab-based experiment performed using Sawbones prepared to mimic an oblique fracture and mounted on a custom rig. The Sawbones were prepared and fixed with different fixation techniques. The rig was used to apply lateral bending and torsional forces to the constructs and data recording software generated results for analysis (Figure 3). We found that fixation by dynamic compression plates was about 40% stiffer than fixation by third tubular plates, regardless of using a lag screw. There was little difference in torsional strength. We also found that adding a lag screw did not influence the stiffness of the fixation. The results therefore brought into question the mechanical value of adding a lag screw to this type of fracture configuration. This study questions current practice and encourages further similar studies in order to draw concrete conclusions that may affect clinical practice. The study has been presented at the 19th EFORT international conference in Barcelona also in the Journal of Orthopaedics, a peer-reviewed international journal.
Figure 3: Fibula specimen fixed with a plate and placed in a testing machine
Tennis Elbow Platelet-rich plasma Injection Study
Platelet-rich plasma (PRP) versus autologous whole blood versus saline injection in the treatment of resistant tennis elbow – a pilot study.
Cormac Kelly, Johanna Wales, Jan Herman Kuiper, Megan Hyne, Leighann Sharp, Julie Lloyd Evans, Charlotte Perkins
Funded by the Orthopaedic Institute and the British Elbow and Shoulder Society. Consumables and equipment are being provided free of charge by Lavender Medical.
Tennis elbow is a common condition that causes lateral elbow pain. It is associated with repetitive activity at work and play and is thought to be caused by micro-tears in the tendons of the elbow. Although many cases resolve over a period of 3 months, either with or without non-surgical treatments such as rest, exercises and bracing, other treatments may be necessary such as corticosteroid injections or surgery.
In an autologous blood injection, blood is taken from the patient and re-injected around the affected tendon. Autologous blood injection is thought to promote healing through the action of growth factors on the affected tendon.
The injection is given using a technique called needle barbotage that disrupts tendon fibres and is also thought to promote the healing process.
Either whole blood can be injected, or a fragment known as platelet-rich plasma (PRP) can be separated from the red blood cells and then injected. PRP may have a more effective tendon repair potential compared to whole blood however there is a lack of well-designed studies to support this.
Autologous blood injection has been identified by the National Institute of Clinical Excellence (NICE) as a technology that requires further research.
We chose to carry out a pilot study of 30 patients initially, in order to ensure a well-designed study that will reach its recruitment targets, help to inform the number of participants needed in future studies and investigate measures that are both clinically relevant and important to patients. All participants will be required to complete a standardised program of physiotherapy prior to enrolment in the study to ensure that their symptoms cannot be relieved by more conservative means. Participants will then be allocated to one of three treatment groups at random, (an injection of whole blood, PRP or saline). Assessments of pain and elbow function will be carried out at 6 weeks, 12 weeks, 6 months and 1 year. We will also collect information on any side effects experienced, use of pain medications, quality of life and satisfaction with treatment.
Recruitment has progressed more slowly than we anticipated, with 23 of the target of 30 enrolled; we anticipate that recruitment will be complete by November 2018.