Approximately 20% of people with chronic high (proximal) hamstring tendinopathy who undergo non-invasive (conservative) treatment, such as rest and physical therapy, have residual hamstring pain.1-5 For those that find no relief from non-invasive (conservative) management, minimally invasive treatments such as ultrasound-guided corticosteroid injections, ultrasound-guided needle tenotomy, ultrasound-guided platelet-rich plasma (PRP) injections, or ultrasound-guided percutaneous (through the skin) ultrasonic tenotomy may be pursued.
Injecting a corticosteroid into the ischial bursa has been shown to be beneficial to some patients with chronic hamstring tendinopathy.5 The ischial bursa is a small, fluid-filled structure that acts as a buffer between the overlying gluteal muscles and hamstring tendons at the sit bone (ischial tuberosity). A doctor uses ultrasound to help guide the injections of anesthetic and corticosteroid solutions into the bursa.
Cortisone injections should not be made directly into a tendon, because cortisone can damage tendon tissue over time; however, there is no reliable literature documenting this potential negative outcome with peritendinous (around the tendon) injections.1,4 Qualified practitioners can now use ultrasound to guide the needle into the ischial bursa and avoid inadvertent placement of steroid into the tendon or the sciatic nerve. Ultrasound has greatly improved the safety and accuracy of steroid injections.6
Ultrasound-Guided Needle Tenotomy
This in-office procedure is done using ultrasound guidance and may be an option for patients with refractory symptoms. The physician will first numb (anesthetize) the area and the needle track and tendon using local numbing medicine. Following this, the physician, using ultrasound guidance, introduces a slightly larger needle into the tendon and manipulates it in a back-and-forth motion to create bleeding and tissue damage, bringing blood and platelets to the area, with a goal of promoting new growth factors and healing.7-12 The use of ultrasound-guided needle tenotomy for chronic tendinopathies has been reported with good success and represents another possible treatment option for patients with recalcitrant tendinopathies.4,7-12
Platelet-Rich Plasma (PRP) Injections
Ultrasound-guided tendinous injection of platelet-rich plasma (PRP), with or without needle tenotomy, has emerged as a promising treatment of tendinopathies.4,7,13-17 PRP most simply defined is a volume of platelet count that is above a patients normal blood levels of platelets.18,1 This is an office-based procedure that requires the patient’s own blood, which is drawn and put into a centrifuge to separate it into layers. The concentrated platelet layer is then put into a syringe and injected into the damaged area under sonographic guidance. Platelets are the body’s “healing cells” and when injected release a multitude of “growth factors” that have regenerative and healing properties.17,19-23 In general, it is believed that PRP, by releasing of growth factors locally into a damaged tendon, will induce tissue healing and regeneration.19 Patients are usually told to avoid non-steroidal anti-inflammatories, such as aspirin, ibuprofen, naproxen, and celecoxib (Celebrex) for 7 to 10 days prior to the injection, as these medications bind platelets and temporarily inactivate them. This would essentially result in pre-deactivation of the PRP that was being used in the treatment.
PRP has been shown to be beneficial in improving function and reducing pain in patients with tendinopathies and has consistent level 1 data for treatment of “tennis elbow” (lateral epicondylitis).14-16,24,25 Recently, it has also been used effectively with good results in patients with persistent high (proximal) hamstring tendinopathy.4,13,26 The patient should be aware that PRP can be extremely painful immediately following the injection and for the first two weeks. This is believed to occur secondary to the large amount of inflammatory cells being injected into a small area. The patient should also be aware that PRP can take some time to work and typically has the most benefit 6 to 12 weeks after treatment.14-16,19,24 While it's not considered standard practice, PRP represents a viable emerging minimally invasive treatment option for patients who have not found success with non-invasive (conservative) management. Further investigations into PRP's long term benefit and effects on proximal hamstring tendinopathy are needed and ongoing.
Ultrasound-Guided Percutaneous Needle Tenotomy (Tenex Procedure)
In 2011, the FDA approved needle ultrasonic tenotomy, sometimes called the fenestration and removal of scar tissue (FAST) procedure, for the treatment of tendinopathies.27-29 This technology is similar to the technology used to remove cataracts from the eyes.28
This procedure is performed in the office or outpatient surgery center. The physician starts by numbing the skin and procedure site. Following this, the physician makes a small puncture in the skin with a scalpel, and the device is inserted into a diseased tendon under sonographic guidance. The device itself is then turned on and has a tip that vibrates at a rapid rate, emulsifying tissue in front of it and irrigating it through an outflow suction.27,28
Theoretically, by removing the diseased tissue—similar to a decubitus ulcer treatment—the body can then lay down new tissue. There is emerging evidence that this procedure may be superior to the traditional surgical management with a large incision.29 Further research on long-term outcomes is ongoing.