Surgical approach to lower extremity nerve decompression in the patient with diabetic neuropathy

Abstract

Neuropathy associated with Diabetes is increasing at epidemic rates throughout the world. Traditionally, this neuropathy causes loss of protective sensation leading to ulceration, infection , and amputation. Even with good glycemic control, this neuropathy is still considered progressive and irreversible. In many patients with diabetic neuropathy there is also associated pain and loss of balance, requiring expensive neuropathic pain medication and treatment of hip and wrist fractures. In 1988, Dellon observed that therecould be a new optimism for this problem, because the metabolic neuropathy made the peripheral nerve susceptible to compression, which might be responsible for these clinical symptoms and sequelae. In 1992, Dellon published the first clinical research documenting that decompression of peripheral nerves at known sites of anatomic narrowing could relieve the symptoms of neuropathy and prevent ulcers and amputations. In this Thesis, the primary hypothesis tested is that the metabolic neuropathy of diabetes makes the peripheral nerve susceptible to nerve compression at known sites of anatomic compression, and that decompression of these superimposed compressions can relieve the symptoms and thereby alter the natural history of diabetic neuropathy. The basic animal science research models and anatomic investigations that form the basis for this clinical approach are described and their results documented. New clinical outcome studies are described and their results documented. The summary of this research is that: I) The ideal patient for surgical decompression of peripheral nerves who has diabetes is one who can have the degree of neuropathy documented and staged by neurosensory testing with the Pressure-Specified Sensory Device and one who has clinical evidence of nerve compression with a positive Tinel sign at known anatomic sites of narrowing; the common peroneal nerve at the fibular head, the deep peroneal nerve over the foot dorsum, and the branches of the tibial nerve in the four medial ankle tunnels. Furthermore, the patient should have sufficient blood supply to the foot and be without edema in the foot to permit satisfactory wound healing. II) Given the above inclusion criteria for surgery, it can be expected that there will be an 80% chance of relief of pain from an 8.5 to a 2.0 on a Visual Analog Scale within 3 months of surgery, and an 80% chance to improve sensibility significantly within one year after surgery. III). In the group of patients for whom sensibility is restored, the natural history of diabetic neuropathy will be changed such that there will be no ulcerations and no amputations. IV) In patients who have bilateral Dellon Triple Nerve Decompression surgery, balance will be improved minimizing the risk of fractures due to falls. It is concluded that patients with diabetes who have superimposed nerve compressions in the lower extremities can achieve relief of symptoms and prevention of ulceration and amputation by decompression of these multiple sites of nerve compression using the operative approaches described in this Thesis.