Surgical reinnervation of the dentate anterior muscle in long-term idiopathic neuropathy of the long thoracic nerve: a case report

Cases of pterygoid deviation (deviation) of the scapula are associated with dysfunction of the muscles of the primary stabilizers of its superior medial and inferior medial edges. One of the factors of KDL is idiopathic neuropathy of the long thoracic nerve (LPN). The ineffectiveness of therapeutic methods of treatment of KDL can be compensated by the use of surgical correction methods. Carrying out decompression of the DGN makes it possible to achieve partial regression in 87 % of patients and complete regression of the deficiency — in 62 % in terms of up to 6 months. The method of selective targeted reinnervation of nerve structures — neurotization is devoid of a number of disadvantages of traditional surgical methods, makes it possible to eliminate the influence of the time factor on the complex process of denervation/reinnervation and ensures the predictability of the outcome. A 27‑year‑old male attended the department with pain in the right shoulder joint, limitation of flexion in the right shoulder joint to 130°, external rotation of the shoulder to 75°, abduction of the right shoulder to 150°. The function of the right deltoid muscle is within the normal range (M5 according to the British MRC scale), KDL at rest (static) and during movements (dynamic). The duration of the disease is about 7 months. Electroneuromyography (EMG) revealed a violation of the conduction of motor fibers of the DGN and a long‑standing denervation process without signs of reinnervation in the dentate anterior muscle (DAM). The patient underwent neurotization of the DGN with the anterior portion of the thoraco‑spinal nerve (PP GSN) according to the method of C. B. Novak and S. E. Mackinnon. A follow‑up examination of the patient was carried out 9, 15 and 19 months after surgical reinnervation. In addition to clinical neurological examination, ENMG was performed. The pain in the right shoulder girdle regressed completely. Full regression of the KDL at rest (static) and partial during movements (dynamic) of the right upper limb was noted. The ENMG data confirmed the reinnervation of the PZM. The use of a more aggressive surgical approach — neurotization made it possible to bring the axons with preserved function (PP GSN) closer to the end motor plates of the non‑functioning nerve (DGN), which contributed to achieving a positive functional result — the restoration of PZM. Selective use of PP GSN made it possible to preserve the functionality of the latissimus dorsi muscle at the expense of preserving the posterior portion of the nerve donor.