Botox-like injections treat runners, cyclists with knee pain
LPOS sufferers experience pain in the front and side of the knee joint.
In a first, a team of researchers has used Botox-like injections to treat runners and cyclists suffering from a painful knee condition that affects more than one in eight active people globally.
Researchers from Imperial College London and Fortius Clinic carried out a trial involving 45 patients with what they term lateral patellofemoral overload syndrome (LPOS).
The trial involved an injection of Dysport which, like Botox, is a type of botulinum toxin into a muscle under ultrasound guidance, at the front and outside of the hip, followed by personalised physiotherapy sessions.
Sixty-nine percent of patients required no further medical interventions and had complete pain relief when followed up five years later.
Previous studies have shown that 80 percent of patients reported experiencing ongoing symptoms after conventional treatment, with 74 percent experiencing reduced activity levels.
"Many athletes who took part in this study had exhausted all other treatment options and this was their last resort. We are really excited that our approach is showing positive results for patients, which could have implications for active people around the world," said physiotherapist Dr Jo Stephen from Imperial College London and Fortius.
The team estimates that one in five active females and one in eight active males have these symptoms.
"This research is a really exciting step forward in the management of a very common cause of knee pain in athletes. Our results show that botulinum toxin can provide better and longer lasting pain relief than the current, conventional alternatives," added Sam Church, co-author and consultant knee surgeon from Fortius Clinic.
The team had previously noted that patients with LPOS symptoms overused their tensor fascia lata muscle in the hip instead of the gluteal muscles in the buttocks.
They suspected that this was the reason why physiotherapy treatment often did not help patients to strengthen their buttocks as the tensor fascia lata muscle was over-compensating when they were doing the supposed strengthening exercises.
In the study published in the American Journal of Sports Medicine, the team first showed that using physiotherapy alone on patients failed to alleviate their pain.
The patients then had an injection of Dysport into the front hip muscle, helping it to relax so that the buttock muscles had to be used more.
Patients followed the injection with further physiotherapy to strengthen their buttocks muscles and address other weak or tight muscles as appropriate.
"Our findings show botulinum toxin has revolutionised the treatment of these patients," noted David Urquhart co-author from Chelsea and Westminster Hospital.
The next step will see the team analysing muscle activity pre and post Dysport injections with further computational analysis to explore the mechanisms at work.