How hamstring reinjury is holding back recovery

Dr Noel Pollock 0922_10

Despite the increase in therapy and awareness of hamstring injuries (HSIs), injury rates have not declined in the last two decades. HSIs are the most common athletic injury in highly active sports and is associated with the greatest burden and time loss for patients with muscle injuries.

Dr Noel Pollock is a consultant at the Institute of Sport, Exercise and Health (ISEH), part of HCA Healthcare UK and he is Chief Medical Advisor for British Athletics and part of the British Olympic team. He is an expert on hamstring injuries and has been working on a strategic approach to help reduce reinjuries of this muscle.

HSIs, such as T junction injuries, and proximal hamstring tendons tears can be complex and require different types of rehabilitation. Dr Pollock helps patients with a wide range of HSIs, while aiming to reduce chances of reinjury.

"High-speed running, a quick change of direction and kicking – combine these sudden movements with not having capacity in the muscular system and HSIs may occur," says Dr Pollock. Several risk factors for HSIs include the lack of hamstring muscle strength in certain positions, tackle situations in football, or eccentric muscle contractions. Previous muscle injuries such as calf injuries can also increase the risk of reinjury.

Working to reduce the chances of hamstring reinjury

Most referrals to the ISEH are from physiotherapists who want Dr Pollock’s expertise in diagnostics, understanding the classification of injury and an overall rehabilitation plan. "We can do that in detail, supporting both the patient and physio all the way through that process," says Dr Pollock. "We make sure to include the patient’s physio throughout the treatment so they can continue the close relationship with the patient."

Many HSIs are reinjuries, and Dr Pollock states, "Often in HSIs, the severity of injury involves the tendon. If that's not recognised early, there is a high risk of reinjury. If the initial injury isn't rehabilitated well, the injuries take longer to recover, and the risk of further injury increases again. Patients can get into this cycle of a recurrent HSI." He continues, "We are getting much better at diagnosing specific HSIs earlier. Take for example some athletes who had recurrent HSIs, they are having less reinjury, through correct rehabilitation and advice on how to recover quickly."

Severe hamstring injuries

For different people, Dr Pollock stresses surgery would have different outcomes. "I would lean towards the rehabilitation side for most HSIs. But that's a really important area we are focusing on. Surgery may be a good option for future treatment but work still needs to be done on the complications and on the necessity for certain types of HSIs."

"It’s not straightforward. Some of the more severe hamstring injuries have less pain when you lose tension," says Dr Pollock. "In some injuries involving the tendon, there can be complications with large gaps between the ends of the tendon, or retraction of the muscle. There are surgical options which have good outcomes in terms of return. It's fair to say there's currently a debate on the necessity of surgery versus rehabilitation," says Dr Pollock.

International collaboration

Injuries to several parts of the hamstring muscle heal differently depending on the different tissues that are involved. Dr Pollock and an international cohort of 46 HSI experts proposed a new way to classify muscle injuries based on the site of the hamstring injury. He states, "There's lots of discussion about the importance of identifying tendon injuries. We have recognised and hypothesised hamstring injuries are of distinct types, and proposed different grades which link to recovery times and risk of reinjury."

Dr Pollock and the international expert group published in the British Journal of Sports Medicine. This narrative evidence review is an international consensus on best-practice decision-making for the classification of hamstring injuries. The experts, made up of sports medicine physicians, physiotherapists, surgeons, trainers and sports scientists were invited to a face-to-face consensus group meeting in London. Fifteen of these expert clinicians attended to refine statements around the management of hamstring injuries.

They considered critical prognostic and risk of reinjury factors for certain hamstring injuries involving tendons. The panel recommended that hamstring injury classification systems evolve to integrate imaging and clinical parameters around individual muscles, injury mechanism, sporting demand, functional criteria and patient-reported outcome measures.

A great deal of Dr Pollock’s work is through collaboration, working as a team at the ISEH and with consultants at HCA UK’s The Princess Grace Hospital. "We consider both rehabilitation and surgical aspects in a discussion to make better decisions. There's a lot of preparation and discussions around the benefits and the treatment for patients."

To decide if surgery or rehabilitation are the best option for patients, Dr Pollock states it's important to assess the clinical history and mechanism of injury, while exploring the risk factors in a clinical examination. For assessing hamstring and general musculoskeletal function, imaging can determine severity and whether the injury involves the tendon. Dynamic ultrasound scans assess the injury in real time to look at the muscle and tendon tissue and a 3T MRI scanner gives detailed images.

From these investigations, an accurate diagnosis of the injury is confirmed, and a decision is made for the best treatment plan. "We see a range of patients, from recreational to professional athletes, and then discuss the treatment options, often with their physios or coaches," says Dr Pollock. "We're getting better at identifying the severity of the injury, and not treating them all as the same. We can also identify the risk of serious injuries returning and decrease the risk of reinjury."

Dr Pollock’s research over the last 10 years demonstrates that if HSIs are diagnosed appropriately, then with structural rehabilitation the risk of reinjury reduces. He says, "We are understanding more through important research, always looking forward and trying to advance the technology or the rehabilitation, including proposing different grading for injuries."

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