SingHealth Duke-NUS Sport & Exercise Medicine Centre breaks down three promising treatment interventions for musculoskeletal conditions.
In the ever-evolving field of sports medicine, three treatment modalities have made their mark as promising interventions for musculoskeletal conditions: platelet-rich plasma injection, viscosupplementation and extracorporeal shockwave therapy.
Here, the SingHealth Duke-NUS Sport & Exercise Medicine Centre breaks down all the essential information for general practitioners to stay in-the-know – a handy tool in the arsenal with the rising prevalence of such conditions.
1. PLATELET-RICH PLASMA INJECTION
WHAT IT IS
Platelet-rich plasma (PRP) injection, classified under a group of therapeutic agents known as ‘orthobiologics’, has emerged as a promising treatment option within the realm of musculoskeletal (MSK) medicine. This innovative approach utilises the patient’s own blood components to promote healing and alleviate pain in various MSK conditions.
What is platelet-rich plasma?
PRP is a concentrated solution derived from the patient’s own blood, containing a higher concentration of platelets and growth factors than what is typically found in whole blood.
Platelets play a crucial role in tissue healing due to their ability to release growth factors that promote cell proliferation and recruitment of stem cells to the injured area (Figure 1).
By concentrating these healing factors and delivering them precisely to the site of pathology, PRP therapy aims to harness the body’s natural healing abilities to accelerate the recovery process and improve outcomes.
The PRP procedure involves drawing a small amount of the patient’s blood and centrifuging it to separate the platelet-rich component from other blood components (Figure 2). The platelet-rich component is then isolated and concentrated. The resulting PRP solution is injected directly into the target region under image guidance (Figure 3).
As PRP therapy is autologous in nature, it is generally considered safe, minimising the risk of adverse drug reactions.
In general, the potential benefits of PRP therapy include:
Promotion of tissue repair
Improved functional outcomes
A potential reduction in the need for more invasive interventions like surgery
However, it is important to note that the effectiveness of PRP can vary based on patient and injury characteristics, PRP preparation methods and injection techniques.
CONDITIONS TREATED WITH PRP
Tendon and ligament injuries
Tendinopathies and ligament sprains are common MSK problems seen in primary care and are often the result of gradual overuse and microtrauma.
On their own, these injuries may be challenging to heal due to limited local blood supply. The growth factors in PRP can stimulate repair of degenerate tissue, enhance collagen production and reduce pain.
PRP has been utilised to successfully treat various tendon and ligament injuries, such as patellar tendinopathy1 (jumper’s knee), lateral epicondylitis2 (tennis elbow), plantar fasciitis3 and rotator cuff injuries2.
Muscle injuries, such as strains and tears, usually develop from actions involving sudden eccentric muscle contractions.
By promoting the regeneration of muscle fibres and reducing inflammation, PRP therapy may accelerate healing and minimise scar tissue formation.4 This can potentially enable athletes and active individuals to return to their sporting activities sooner.
PRP therapy has been explored as a minimally invasive, conservative approach to managing osteoarthritis (OA).
Preclinical studies suggest that PRP has some disease-modifying effects, with positive changes on cartilage tissue and synovial membrane.
Clinical evidence also supports the safety and effectiveness of PRP in the treatment of knee OA, which has been shown to be superior when compared to both placebo (saline) and control treatments such as hyaluronic acid (HA) and corticosteroids. PRP can be indicated in mild and moderate cases of knee OA (Kellgren-Lawrence grade ≤ 3).5
While cognisant that the present Ministry of Health (MOH) guidelines, dated 24 October 2013, do not list OA as an indication for PRP therapy, the 2022 European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) consensus on the use of injectable orthobiologics reaffirms the efficacy of PRP in the treatment of knee OA.5
WHEN IT SHOULD BE CONSIDERED
Most doctors generally accept that PRP therapy is usually not first-line treatment for the management of MSK conditions. However, should the patient’s condition be resistant to regular conservative treatment, next-level interventions such as PRP may be considered.
Alternatively, if the patient is a competitive athlete or a high-demand active individual, and would benefit from an expedited return to physical activity, PRP may be suitable at an earlier stage of treatment.
WHAT IT IS
Viscosupplementation involves introducing exogenous HA into the affected joints, aiming to restore the natural viscoelasticity properties of the joint and promote joint homeostasis while mitigating inflammation-related factors.
Studies have demonstrated that HA has shock absorption properties and the capacity to reduce the levels of pro-inflammatory agents such as PGE2 and NF-kB, along with enzymes that contribute to the breakdown of joint tissue.
The therapeutic effect of HA has been shown to peak at around eight weeks and persist for at least six months. In addition, there is evidence that HA supplementation can delay the need for total joint replacement surgery.
According to MOH, viscosupplementation can be used for the treatment of knee OA where general measures or systemic therapies have failed or are contraindicated (Grade B, Level 1+).
International guidelines recommend viscosupplementation in the management of symptomatic mildto-moderate knee OA as a second-line conservative treatment in non-responders, or in patients who have contraindications to nonsteroidal antiinflammatory drugs (NSAIDs).
Viscosupplementation is also appropriate in cases where comorbidities, contraindications or other concerns limit treatment options. It may also be preferred by patients with more advanced OA, who wish to avoid joint replacement surgery for as long as possible.7
HA is also recognised as a non-doping drug, making it a suitable adjuvant option for athletes with knee OA. When possible, schedule the treatment out of season and adapt to the patient’s sporting activity.
The general viscosupplementation procedure includes:
Relevant patient evaluation and patient consent
Ensuring aseptic joint infiltrationt
The choice of appropriate injection approach according to the joint
The choice of appropriate needle calibre
Aspiration of excess synovial fluid
Injection without resistance to pain
Joint mobilisation following injection
The efficacy of viscosupplementation may vary among individuals, depending on the severity of OA, baseline function and the specific viscosupplementation product used.
Many studies have reported overall positive results in pain relief and function outcomes among patients with knee OA treated with viscosupplementation. The response can vary among individuals, but most found a moderate efficacy of around 20% versus placebo.
SIDE EFFECTS AND SAFETY
General tolerance for HA injection is good with acceptable local tolerance. Main adverse effects may include painful or inflammatory local reactions, but they are usually mild and temporary.
More rarely, pseudosepsis may occur, with early onset one to 24 hours post-injection. Fine-needle aspiration and bacteriological analysis should be performed to exclude septic arthritis in case of any doubt.
ALTERNATIVE TREATMENTS FOR KNEE OA
The goal of knee OA treatment is to reduce pain, enhance joint function and improve the individual’s quality of life. It requires a multimodal approach including non-pharmacological, pharmacological and surgical interventions, individualised for each patient’s symptoms and disease severity.
Conservative management approaches include weight reduction, physical activity and utilisation of both non-steroidal and steroidal anti-inflammatory drugs and opioids.
Among other injection treatments, intra-articular injection with corticosteroids and PRP has been reported as a valid therapeutic strategy for the treatment of knee OA.
3. EXTRACORPOREAL SHOCKWAVE THERAPY
WHAT IT IS
Extracorporeal shockwave therapy (ESWT) is a procedure which uses shockwaves to stimulate healing of the problematic tissue in a number of MSK conditions.
Although relatively novel, it has gained traction worldwide due to its efficacy and minimal adverse effects. This procedure has broadened our choices when it comes to effective non-invasive treatment modalities for such conditions.
ESWT was first used clinically in the 1980s for the treatment of renal calculi. Its effects on bones were first investigated due to the apprehension that shockwaves may damage the pelvic bone inadvertently during its use in the treatment of renal calculi.
Surprisingly, it was found that whilst shockwaves had no considerable effects on intact bone, it may stimulate osteogenesis in fractures on animal models. This led to the first studies into the effects of ESWT on the MSK system.
The use of ESWT has since been expanded to treat many other conditions including plantar fasciitis, lateral epicondylitis of the elbow, calcific tendinopathies of the shoulder and patella tendinopathy.
TYPES OF SHOCKWAVES
There are currently two major types of shockwaves used in ESWT: focused shockwaves and radial shockwaves.
Focused shockwaves have a single pulse, with an abrupt and nearly discontinuous change in pressure, travelling faster than the speed of sound through the medium it is propagating through (Figure 4).
Radial waves are sound waves whose physical properties significantly differ from those of focused shockwaves, with a slower rise time and a lower energy level (Figure 5).
The use of focused shockwaves, especially at high energy levels, requires accurate identification of the area to be treated with radiographic or ultrasound guidance to avoid damage to the surrounding tissue and optimise treatment efficacy.
CONDITIONS TREATED WITH ESWT
The most common condition treated with ESWT within the SingHealth cluster is plantar fasciitis.
Studies have shown that ESWT has a success rate ranging from 34 to 88%, depending on the treatment protocol, devices used and methodology. In an internal audit done at Changi General Hospital, two ESWT treatments with focused shockwave therapy done one week apart had a success rate of about 70%.
The second most common use of ESWT in the cluster is in the treatment of tendinopathies, including:
In vitro studies have shown an increase in the gene expression of collagen types I and III and TGF-ß, followed by the production of nitrous oxide and collagen synthesis in tendons subjected to shockwave therapy. It has been postulated that these mechanisms may play a part in the therapeutic effects seen by ESWT on tendinopathies.
Studies have shown treatment success rates ranging from 68 to 91% depending on the area treated, treatment protocol and device used.
ESWT can be considered in plantar fasciitis or select tendinopathies when initial therapy with eccentric loading exercises and strength and conditioning have failed.
SIDE EFFECTS AND CONTRAINDICATIONS
There have been very minimal adverse effects reported for ESWT treatment, with the most common being transient pain after the treatment, ecchymosis/petechiae and dysesthesia. However, it should be noted that this procedure can be painful during application of the shockwave.
Some contraindications for the use of ESWT are:
Malignant tumour in the treatment area (not as underlying disease)
Epiphyseal plate in the treatment area
As primary care clinics are often the first port of call for patients with musculoskeletal conditions, keeping abreast of the latest treatment modalities is crucial. With a good understanding of the options available, we are better able to advise patients and help optimise their outcomes.
Everhart JS, Cole D, Sojka JH, et al. Treatment Options for Patellar Tendinopathy: A Systematic Review. Arthroscopy. Apr 2017;33(4):861-872. doi:10.1016/j.arthro.2016.11.007
Chen X, Jones IA, Park C, Vangsness CT, Jr. The Efficacy of Platelet-Rich Plasma on Tendon and Ligament Healing: A Systematic Review and Metaanalysis With Bias Assessment. Am J Sports Med. Jul 2018;46(8):2020-2032. doi:10.1177/0363546517743746
Hurley ET, Shimozono Y, Hannon CP, Smyth NA, Murawski CD, Kennedy JG. Platelet-Rich Plasma Versus Corticosteroids for Plantar Fasciitis: A Systematic Review of Randomized Controlled Trials. Orthop J Sports Med. Apr 2020;8(4):2325967120915704. doi:10.1177/2325967120915704
A Hamid MS, Mohamed Ali MR, Yusof A, George J, Lee LP. Platelet-rich plasma injections for the treatment of hamstring injuries: a randomized controlled trial. Am J Sports Med. Oct 2014;42(10):2410-8. doi:10.1177/0363546514541540
de Girolamo L, Laver L. ESSKA ORBIT Consensus - Use of injectable orthobiologics for the treatment of knee osteoarthritis - Part 1: blood-derived products (alias PRP). European Society of Sports Traumatology, Knee Surgery & Arthroscopy. Accessed 25 Aug 2023, https://cdn.ymaws.com/www.esska.org/resource/resmgr/docs/consensus_projects/orbit_consensus_complete2022.pdf
Clinical Assistant Professor Mandy Zhang holds postgraduate qualifications in the Membership of the Royal College of Surgeons (Edinburgh), Masters of Family Medicine (Singapore), Masters of Sports Medicine (Australia), American College of Sports Medicine (USA) as an Exercise Physiologist and a FIFA Diploma in Football Medicine.
She is the Dance Lead for the Performing Arts Medicine Centre (PAMC) and Education Deputy Director for Exercise Is Medicine Singapore. Her clinical interests include sports injury prevention, musculoskeletal sonography and performing arts medicine.
Adjunct Assistant Professor Lim Ang Tee is a Sports Physician at Changi General Hospital. He has a keen interest not only in sports medicine but also in community health, chronic disease management and disability sports. Prof Lim is a designated workplace doctor, a Lasting Powers of Attorney certificate issuer and also on the panel of assessors for disability assessment for Eldershield application.
Dr Joshua Li is an Associate Consultant Sports Physician. He currently practices at Changi General Hospital, Singapore General Hospital and the Singapore Sports Institute. His clinical interests include endurance sports and ultrasound-guided injection therapies. An avid athlete, Dr Joshua is a member of Singapore’s national triathlon team and a competitive marathoner.
GPs who would like more information about platelet-rich plasma therapy can contact Dr Joshua at email@example.com.
GPs can call the SingHealth Duke-NUS Sport & Exercise Medicine Centre for appointments at the following hotlines, or click here to visit the website:
Hospital: 6326 6060
Changi General Hospital: 6788 3003
Hospital: 6930 6000
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Children's Hospital: 6692 2984