7th September 2022
When so much focus is placed on the frontiers of surgical technology – including new applications such as augmented reality, image guided surgery or 3D printing – it is easy to forget that what are now considered as routine surgeries deliver a hugely positive impact on people’s lives.
One example is total knee arthroplasty (TKA) surgery, more commonly known as a knee replacement. First performed in 1968, TKA has become one of the most reliable, effective and successful surgeries to enhance the lives of patients.
When a patient needs TKA surgery
TKA is required when patients experience constant knee pain, stiffness or swelling in the knee joint, severely reducing their mobility.1 It can cause lack of sleep and make everyday tasks difficult or impossible, significantly reducing quality of life.
Common causes of knee pain include arthritis, haemophilia and disorders causing abnormal bone growth. While TKA can be performed on adults of any age, the majority take place on those between the ages of 60 and 80. In a 2019 paper, Singh et al estimated the number of TKA surgeries likely to take place in the future in the US. The paper estimated that in 2020 the number would be in excess of one million, rising to more than three million by 2040.2
A complex surgical intervention
While the surgery is common it is not simple. Damaged elements of the knee joint are removed and replaced with an artificial joint made up of plastic and metal elements, carefully created to precisely replicate the individual’s knee. The surgery can take between one to three hours, and patients may need to remain in hospital for up to five days after the operation is complete. Patients usually need help to move for around six to eight weeks and – like any surgery – full recovery can take more than a year. As with all surgical interventions, TKA patients can have post-operative complications. The most common short-term issue is infection, which can usually be treated with a course of antibiotics.
Although patients are being discharged earlier than in the past, a small but significant number of TKA patients return to the emergency department due to oedema related complications – oedema is the medical term for swelling.
A published study by Kelly et al, sought to identify common reasons for 90-day emergency department (ED) visits, following total joint arthroplasty (TJA). The study reports post-operative oedema as one of the top three surgery related reasons for post-operative complications following total hip arthroplasty (THA) and knee arthroplasty (TKA). One in ten patients return to ED within 90 days of TJA, incurring costs for clinician time and diagnostic scans and tests to determine and prescribe appropriate treatments3.
Addressing post-operative oedema
Current mechanical methods to reduce post-operative oedema following TKA include intermittent pneumatic compression (IPC), a boot-like cuff that compresses the leg to increase blood flow. IPC is not suitable, however, for all patients. Patients with fragile skin, or complex limb injury can struggle with IPC. Furthermore, the pneumatic pumps that operate the IPC cuffs are not always readily available.
Another non-pharmaceutical option is Cryotherapy, which has evolved from simple ice sleeves (or gel packs) to more refined devices employing electronically controlled cold fluid or air circulation. Both therapies are used immediately post-surgery and while they provide some benefits, their use is controversial4,5 and both require resources to correctly fit the devices.
Other oedema treatments include continuous passive motion, manual lymph drainage and limb elevation. However, many of these therapies are poorly understood or lack adequate evidence of effectiveness.4
An opportunity for MedTech innovation
To solve the oedema burden, it is important to consider the vascular nature of the condition, and how increasing blood flow in a lower limb can provide the key for swelling reduction pre and post-operatively and in non-surgical patients4.
Through its innovative mechanism of neuromuscular electrostimulation, the battery powered, geko™ device speaks to this. It is applied non-invasively to the skin over the common peroneal nerve at the side of the knee. It gently stimulates the nerve, once every second, activating the calf and foot muscle pumps resulting in unparalleled, increased blood flow in the deep veins of the calf6, at rate equal to 60% of walking7, without a patient having to move. This unique mechanism of action – the combination of calf muscle activation and blood flow increase – is clinically proven to reduce both fluid leakage in the capillary bed and to accelerate oedema clearance by local reabsorption of excess interstitial fluid via the vasculature and lymphatic system8,9.
Initial use of the geko™ device, however, had not been oedema management. The discovery that it could positively impact oedema reduction was a stroke of good fortune. While working with leading orthopaedic clinicals, who were exploring use of the geko™ for post-operative venous thromboembolism (VTE) prevention, its effect on oedema reduction was first observed.
This led to the completion of several pre- and post-operative studies. Of note is a randomized controlled trial (RCT) published by Wainwright et al9 that compared the post-operative effect of the geko™ device to compression stockings (standard care) in hip replacement patients, reporting superior prevention of oedema build-up in the geko™ arm – with all patients reporting the device as well tolerated.
Also of note, is a pre-operative study by Baker et al8 which measured the time to surgery in ankle facture patients requiring surgical fixation and their tolerance to the geko™ device. The results showed accelerated time to surgery – a statistically significant two-day reduction in readiness for surgery, due to oedema reduction – again, all patients reported the geko™ device as well tolerated.
Influenced by this data, a real-world study in the US is fitting the geko™ device to TKA patients immediately post-surgery. When they are ready to go home, the patients are trained to self-fit the device and provided with geko™ treatment packs to maintain their oedema prevention – enabling rehabilitation to begin sooner in the home setting.
Addressing an unmet need and saving healthcare systems money
The published data and an ongoing program of studies demonstrate the geko™ device efficacy and offers, for the first time, an innovative medical intervention – where previously few or no effective tools have been available. A device that is both easy to use and clinically proven and can provide clinicians and patients with the means to control both surgical and non-surgical related oedema in the hospital and home care setting for enhanced patient recovery, reduced emergency department visits and health system savings.