Trigger thumb is known as a disorder characterized by snapping or locking of the thumb. Most cases are secondary to thickening of the digit’s A1 pulley, but other pulley sites, the metacarpophalangeal joint or the carpal tunnel can be involved. As a result, a consideration of these areas and surrounding tissues is reasonable and should be considered in a complete assessment.
Digital tendon flexor sheaths have a membranous synovial component and a ligamentous retinacular component. The ligamentous retinacular component is called the pulley. There are two types: a cruciate pulley and an annular pulley. The annular pulleys undergo the greatest stress from the flexor tendon.2
The most proximal annular pulley is called the A1 pulley and is 5mm proximal to the metacarpal phalangeal joint, distal to this are pulleys A2, A3 and A4. The pulleys possess two layers. The outer vascular layer is a dense capillary network, and the inner is composed of dense collagen bundles with spindle shaped fibroblasts;1
this avascular layer is nourished by diffusion from the synovial fluid. When injured, the pulleys have been observed to possess thick and fibrous tendon sheaths, and exhibit nodular and fusiform swelling covered with granulation tissues.2
The tissue displays increased chondrocytes, and increased glycosaminoglycans, with proliferation of fibrous tissue.8
Because of these changes, there is decreased space for the flexor tendon to pass under the pulleys and it becomes trapped.
Graston Technique®, also referred to as an augmented soft tissue mobilization technique, employs specially designed stainless steel instruments with beveled edges to augment a clinician’s ability to perform soft tissue mobilization. The instruments are utilized in a multidirectional stroking fashion applied to the skin at a 30°–60° angle at the treatment site. This application allows the clinician to detect irregularities in the soft tissue texture through the undulation of the gliding tools.9
In addition to removing scar tissue adhesions, Graston Technique®
is proposed to enhance the proliferation of extracellular matrix fibroblasts, improve ion transport and decrease cell matrix adhesions.10
Augmented soft tissue mobilization has been suggested to be useful in the treatment of chronic ankle fibrosis and to loosen tight patellar retinaculum.11
and ART techniques have been proposed to remove adhesions, and promote the restoration of normal tissue texture. Good results for these treatment goals using Graston Technique®
and ART techniques have been shown in the resolution of conditions including lateral epicondylitis,12
and carpal tunnel syndrome.14
It follows that the treatment of trigger thumb using these techniques on the pulley structures of the flexor tendon, the carpal tunnel and surrounding tissues is both appropriate and reasonable.
Active Release Technique is designed to accomplish three unique objectives: restoring free and unimpeded motion of all soft tissues, the release of entrapped nerves, vasculature, and lymphatics, and to re-establish optimal texture, resilience, and function of soft tissues.15
It is suggested by the authors that this protocol be completed before surgical intervention is attempted. Treatment should be initiated at the onset of symptoms or at the earliest time available. Symptom and objective improvement is often evident in the first to third treatment.15
A 50% improvement within this timeframe is common and may be expected.15
The chronic nature of the symptoms associated with trigger finger makes conservative treatment difficult and often frustrating. Still conservative care is always recommended as a treatment plan prior to surgical intervention.4,12,13,14,16,17
Complications of surgery of tendon reconstruction include synovitis around the implant, infection or wound breakdown, disruption of the distal implant juncture, and flexion deformity of the proximal or distal interphalangeal joint.18
Adhesions may also develop as a result of the surgery, which may prevent a successful recovery of the digital motion and may require tenolysis.1,7, 8,18
Contractures may also develop during the post-operative phase.18
Open surgical release of trigger thumb has a repeated success rate of between 97–100% but may be complicated by nerve damage.5
Other research indicates that modalities such as ultrasound, heat, and massage can help control pain by affecting the local metabolism of the involved sites by resolving local edema by breaking up proteoglycan bonds that hold water.4,12
Corticosteroids have been shown to be effective in the first two weeks of treatment but the patients improvement deteriorates by 3 months (failure rate of 41%). 12
Percutaneous trigger thumb release with a hypodermic needle combined with steroid injection had a higher success rate (91% than steroid injection alone 47%).19,20
Active Release Technique has had a 71% success rate, measured subjectively in an observational study treating lateral epicondylitis and carpal tunnel syndrome.4
After 4 weeks of treatment with ART, 50% of patients being treated for a tendinopathy were discharged. 13
Overall, published research studies do not favor any particular type of treatment for the resolution of trigger thumb. There is not sufficient scientific evidence to favor any particular type of treatment for a flexor tendinopathy. Non-operative treatment has been deemed highly successful in clinical practice and is preferable over surgery. Research efforts should focus on demonstrating the most cost-effective and least invasive treatment options for patients with a flexor tendinopathy.
The results of this study demonstrate improvements in range of motion, pain and function within 8 treatments using ART and Graston techniques on the flexor pulleys and flexor pollicis. Subjectively the patient felt better and was satisfied with the outcome.