Diabetes is a systemic disease with wide ranging manifestations due to defects in insulin production or organ receptor sensitivity to this critical hormone. It has profound effects on the cells comprising the circulatory, nervous and connective tissue systems. This widespread involvement of systems is expressed in the hand, a complex organ of function comprising multiple tissue types.
The treatment requires recognizing the diverse expression of this disease in this wonderful tool that is both an organ of functioning expression as well as sensation. Typically, diabetes patients have symptoms that are due to these problems going unrecognized. Often times, they are not severe, and hence are not brought to the attention of the primary care physician or endocrinologist. In other cases, the symptoms are not recognized as being a manifestation of a very treatable problem. The hand surgeon should be involved at an early time when any of these symptoms present as the pathology can be arrested at an early stage and avoid more severe morbidity.
Numbness or tingling in the fingers is often ignored until it becomes persistent or painful. This if often interpreted as neuropathy and occurs commonly in the foot. However, the foot is much more commonly involved with neuropathy and leads to different and more severe problems with ulceration, since it is a weight-bearing organ. This tingling, or “paresthesias”, is more often due to nerve compression in the upper extremity. Most commonly, carpal tunnel syndrome is present, which is median nerve compression at the level of the wrist. It is actually due more to inflammation of the surrounding flexor tendons, rather than direct pathology of the nerve itself. The nerve can be more sensitive to compression if an element of neuropathy is present. Patients typically complain of numbness or tingling in the thumb or central fingers. This is often worse at night and can cause difficulty sleeping. Chronic and severe compression of the nerve leads to weakness of the thumb with subsequent difficulty in many daily tasks.
The diagnosis of carpal tunnel syndrome is usually made through a careful history and physical exam of the hand, and confirmed by nerve conduction studies, which measure the electrical conduction of the median nerve through the wrist. The treatment initially consists of sleeping with a night splint, which keeps the wrist in a neutral position, and high doses of vitamin B6. Anti-inflammatories may help as well, and in certain indications a cortisone injection in the wrist. However, the majority of cases with significant persistent symptoms will require a decompression of the carpal canal to take pressure off the median nerve. This has been traditionally done by an open incision, but can now be done endoscopically in a minor procedure with local anesthesia. Patients can use the hand immediately after the outpatient procedure, and only need to miss a minimum amount of work and can usually forego any therapy.
The cause of carpal tunnel syndrome is really a thickening and inflammation of the tendons that pass in the tunnel along with the delicate nerve. This same tendonitis deep in the wrist causes mechanical problems and pain farther along in the palm. Inflammation of these flexor tendons as they travel to the finger leads to pain in the palm of the hand with occasional “triggering” or catching of the tendon in the tunnel as the patient attempts to extend the finger after flexing. Occasionally, the problem is severe enough that the finger locks, and the opposite hand is used to forcibly extend the digit. This can be accompanied with considerable pain that often radiates up the arm, and difficulty in making a tight fist, particularly in the morning upon awakening. The treatment is quite simple, involving either reducing the tendon inflammation or opening the tunnel through which it passes. A Corticosteroid injection along the tendon sheath is very effective, unless the patient experiences locking where the mechanical problem is more profound and requires a mechanical solution. A trigger finger release is done by a small incision in the palm and opening the tight sheath containing the tendon allowing it to glide once again. In isolated cases of trigger finger, we can even do this percutaneously, without making an incision. This is also done under local anesthesia, and the dressing is removed the very next morning by the patient himself. Open release of the tendon pulley is usually done in conjunction with a carpal tunnel release, as they commonly occur together since they are different manifestations of the same pathology.
There is a misconception that cortisone injections are harmful to patients, particularly diabetics. This is not the case when limited to several injections spanned out over time and in low doses and different locations. This medication tends to stay in the local area injected and does not affect the patient systemically. Nevertheless, these pathologies often do not respond adequately to this treatment, and these minor procedures should be performed. This is commonly the scenario is other locations such as certain types of wrist tendonitis, like dequervain’s tenosynovitis, or bursitis of the shoulder, where an arthroscopic excision of bursa can be done to alleviate and usually cure the problem.