A sudden pop with pain high in the back of the thigh, bruising and weakness can be a proximal hamstring tendon avulsion rather than a routine pulled muscle. It needs prompt assessment; booking PRP first could delay the diagnosis and a treatment discussion that depends on the exact injury.
An avulsion does not automatically mean surgery. A 2024 randomised trial found non-operative treatment was non-inferior to surgery for its main two-year outcome in the adults studied. That finding supports an informed specialist decision, not self-treatment or a claim that PRP can reattach a tendon.
What is a proximal hamstring avulsion?
The hamstrings run down the back of the thigh. Their upper tendons attach near the sitting bone of the pelvis. An avulsion is an injury in which a tendon pulls away from its attachment; it may sometimes pull a fragment of bone with it.
This is different from a strain within the muscle or at the muscle-tendon junction. The distinction matters because the number of tendons involved, any retraction and associated nerve symptoms can affect treatment choices. The word hamstring on a booking form is not enough to identify the problem.
A sudden stretch under load, a slip or a sporting movement can cause this type of injury. Pain may be high near the buttock, and sitting or walking can be difficult. Bruising can extend down the back of the thigh rather than stay at the point of injury.
What needs to be assessed?
The clinician should ask exactly how the injury happened, whether there was a pop, when bruising appeared and what you can now do. Examination includes walking, strength and any signs of nerve involvement. Do not repeatedly stretch or stress the leg to test whether the tendon is intact.
MRI or ultrasound can help define a tendon injury. An X-ray may be relevant where a bony avulsion is suspected. Imaging should answer the clinical question, including the extent of injury, rather than simply provide a label that says tendinopathy.
New numbness or weakness needs prompt review. Severe injury with inability to walk safely, rapidly increasing swelling or concerning symptoms should be assessed urgently, not held for an elective PRP consultation.
Discuss a hamstring injury with The London PRP Clinic. Describe the injury mechanism and current weakness when you enquire so the appropriate assessment route can be considered.
Does a torn tendon always need surgery?
No. Older treatment summaries often place considerable emphasis on surgical repair for complete proximal avulsions. More recent evidence makes a blanket rule inappropriate.
The PHACT trial, published in NEJM Evidence in 2024, randomised 119 adults aged 30 to 70 with proximal hamstring avulsions. At two years, non-operative treatment was non-inferior to surgery on the trial's primary hamstring function score. There were nine observed adverse events in the surgical group and three in the non-operative group, but these counts do not prove that every individual's risks are the same.
The trial does not say that no one benefits from surgery, and its findings should not be extended automatically to children, elite athletes or injuries outside the population studied. Your injury pattern, function, goals, other health conditions and ability to undertake rehabilitation remain part of the decision.
Why seek assessment promptly if rehabilitation may be enough?
Because non-operative treatment is an active plan after diagnosis, not simply waiting to see what happens. A specialist needs to identify the injury and discuss the options while accounting for the time since injury, tendon retraction and any nerve involvement.
A 2023 clinical review describes the difficulties that can follow missed injuries and the variability in both surgical and non-operative rehabilitation. The later randomised trial adds stronger comparative evidence, but it does not remove the need for an early, individual discussion.
Do not read a study result as permission to return immediately to running or stretching. Loading and progression should be agreed for your injury. Recovery goals should include walking, sitting and strength as well as any eventual return to sport.
Where does PRP fit?
PRP is a preparation from a person's blood that concentrates platelets. It has been investigated for some hamstring injuries, but results from muscle strains or chronic tendon pain cannot establish that it repairs a detached proximal tendon.
AAOS describes the role of PRP for hamstring muscle injuries as still under investigation. It is not a substitute for assessing whether you have an avulsion, and the 2024 surgery-versus-non-operative trial was not a trial showing that PRP caused the non-operative outcome.
If PRP is proposed later, ask which specific problem it is intended to treat, what evidence applies to that problem and what it adds to rehabilitation. A biological explanation about growth factors is not proof of a better clinical outcome.
What should a useful treatment discussion cover?
Ask which tendons are involved, whether there is retraction or a bone fragment, and whether nerve symptoms need further assessment. Ask how both operative and non-operative options fit your situation, including risks, rehabilitation demands and likely restrictions.
Bring the scan report and images if already available, previous treatment details and a short account of what has changed since injury. A second opinion is most useful when it reviews the actual findings rather than simply offers a different injection.
Ask The London PRP Clinic in London about assessment and next-step planning. Consultation, imaging, any specialist referral and treatment costs should be confirmed individually; an enquiry does not reserve a procedure or establish that PRP is appropriate.
Sources and evidence limits
AAOS: hamstring muscle injuries explains strains, avulsions, imaging and the investigational role of PRP.
Pihl and colleagues: 2024 operative versus non-operative trial provides randomised two-year evidence in adults aged 30 to 70, not proof of a universal treatment choice.
Looney and colleagues: 2023 review of proximal hamstring ruptures describes diagnosis, treatment selection and rehabilitation. The newer trial should inform interpretation of earlier surgical recommendations.
Information checked 6 November 2026. This article cannot diagnose an injury or provide personal return-to-sport clearance.