de Quervain's tenosynovitis is also known as the washerwoman's sprain, de Quervain's tendinosis of the sheath, radial styloid tenosynovitis and de Quervain's disease. It is primarily a tendinosis of the sheath (cover) that wraps around two tendons of the thumb, the extensor pollicis longus (EPL) and the abductor pollicis brevis (APB).
How does de Quervain's tenosynovitis happen?
The EPL and APB tendons run side by side each other, and have closely and related functions, which is to move the thumb away from the hand by extension (put your hand flat on a table, and bring your thumb out) and/or by abduction (make a "C" of your thumb and hand). What happens is that the tendons run through a synovial sheath (it's like a blanket) which contains them. Due to repetitive motion, this synovial sheath thickens and slowly degenerates, causing inflammation, swelling and pain). de Quervain tenosynovitis is commonly seen in new mothers, as they often lift up and put down their newborn babies; however, studies reveal that this disease is more prevalent in women as they have a greater angle at the greater styloid process, causing a higher level of stress for the APB and EPL at the synovial sheath.
It is primarily a wear and tear, a repetitive strain injury linked to one's role and occupation. As mentioned before, new mothers often carry and put down their new borns, causing additional strain and stress repeatedly at their wrists (and their backs). People whose work involves a flicking of their wrists e.g. opening a can using a spoon or screw driver will also have this injury as well. Also, there is an association caused by handheld devices, which brought about the term "Blackberry Thumbs". which is essentially, de Quervain's tenosynovitis.
Symptoms and Testing
Main symptoms of this condition include sharp pain with thumb and wrist flexion, tenderness at APB/EPL at wrist crease as well as swelling, plus difficulty gripping.
In our physiotherapy and hand clinics in Singapore, we will use the Finkelstein test to diagnose this disease. To perform this test, we get our patients to bend their affected thumb into the palm of their hands, close the other four fingers around the thumb, and bend their wrist downwards. At any point if there is pain, there is an increased likelihood of de Quervain's.
Then we will test for tenderness and swelling at the synovial sheath at the wrist for the EPL and APB. Tenderness and swelling usually confirms the diagnosis, as well as it tells us how acute or serious the condition is (there are mild forms and there are severe forms, where movements are almost impossible).
We also need to do differential diagnosis to rule out possible conditions such as osteoarthritis and wartenberg's syndrome, so that we give accurate and effective physiotherapy treatment.
Physiotherapy and Hand Therapy Intervention
From a medical perspectives, physicians will often provide four types of solutions: pharmaceuticals (painkillers, anti-inflammatory), H&L injection and surgical intervention, and the non-invasive physiotherapy, occupational therapy and hand therapy.
For most cases of de Quervain's tenosynovitis, we will often custom make a splint to fit your hand, to immobilize the wrist and thumb at the meta-carpo-phalangeal joint (the thumb knuckle) but allow your thumb end joint to move - this is for resting the injury and protecting from further injury via mobilization and/or trauma such as blows etc. We also will provide ice therapy to decrease the amount of inflammation and swelling, decreasing the amount of pain experience (pain relief)and retrograde massage. Ultrasound will also help to accelerate the healing process of the synovial sheath and tendons.
The occupational therapist would then determine the cause of the injury, and advise on changes required to activities e.g. the way a task is done if the inappropriate biomechanics was used e.g. lifting a newborn or cutting vegetables. We then determine what activities and exercises to avoid that will aggravate the condition, and strengthen up other muscle groups to help with movements and not aggravate the injury.
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