Mechanism of clavicle epithelium injury
The supraclavicular nerves come from the superficial branch of the anterior branch of the cervical plexus. The nerve originating from the C3 and C4 nerves is the cutaneous nerve, which exists from the anterior of scalenus medius at 1/2 of the posterior margin of the sternocleidomastoid muscle and is immediately divided into three branches, namely the medial, middle, and lateral branches. Then it enters the posterior cervical triangle and lies between the deep and superficial fascia, and pass through the superficial layer of cervical fascia and the lower part of the platysma muscle in turn, and crosses distally over the front of the clavicle, dominating the sense of shoulders, upper chest, and lower neck. The most predisposed site of clavicle fractures is distributed at the 1/3 of the medial lateral of the clavicle [8,10,12-14], and it is relatively easy to damage the clavicular epithelial nerve during fracture or open reduction and internal fixation [3,4,6,11]. In the past, orthopaedic trauma physician often ignored the protection of supraclavicular nerves. Clavicular epithelial nerve injury leads to partial or complete loss of skin sensory function in the corresponding areas under its control such as the shoulder and upper chest, and increases the incidence of traumatic or scar neuroma, which causes "electric shock-like" prickling and affects sleep at night.
Although the skin paraesthesia of the affected side appeared after surgery, which did not affect the motor function of the upper limbs, the patient complained of numbness, prickling, itching, burning sensation and other discomfort in the affected shoulder area and superior lateral thoracic area after surgery. The main manifestations were discomfort such as neck and shoulder pain and soreness [3,4,15]: ① Pain: Acute attack, which can be dull pain, swelling pain, or prickling that can radiate to the head and neck or shoulder-back. ② Restriction of movement: Restriction of movement of the neck, accompanied by neck stiffness and spasm and paralysis of the muscles under its control.③ Paresthesia: Hyperesthesia or hypoesthesia may occur in the nerve distribution area, which affects the daily life of the patient, thereby reducing the patient's quality of life and satisfaction with the surgical effect. Therefore, iatrogenic clavicular epithelial nerve injury should be reduced in the fixation surgery for clavicle fractures, so as to reduce postoperative paresthesia in patients with clavicle fracture and improve patient satisfaction.
Advantages and disadvantages of clavicle fracture reduction and percutaneous external locking plate fixation
It has been reported that minimally invasive surgery for patients with clavicle fractures can reduce the surgical incision of the skin and improve the postoperative aesthetics of the surgical incision, but it cannot avoid the injury of supraclavicular nerve during the operation [15-19]. O'Neill et al. [20] reported that longitudinal skin incisions were placed with clavicle hook plates to avoid clavicular epithelial nerve injury. In 10 cases with ORIF, although the supraclavicular nerve was effectively protected during the first phase of the operation, it could still exhibit symptoms of nerve irritation due to the friction stimulation between steel plate and supraclavicular nerve as a result of the supraclavicular nerve against the surface of the internal fixation plate after the operation. In this group, three of the patients suffered iatrogenic clavicular epithelial nerve injury at the time of incision for the removal of internal fixation 1 year after surgery, and sensory dysfunction in the affected shoulder and superior lateral thoracic areas occurred. In 17 cases with fracture reduction and percutaneous external locking plate fixation, the incidence of paresthesia in the affected shoulder and superior lateral thoracic area was low within 1 year after the operation, and 2 of the patients developed hypoesthesia in the skin of the shoulder and upper chest after the operation, which returned to normal after 1 year of follow-up. The advantages of percutaneous external locking plate fixation surgery are that it effectively reduces the possibility of injury to the supraclavicular nerve in the first-stage of internal fixation and the second-stage of removal of internal fixation [20-23]. However, there are also shortcomings: Postoperative redness and swelling around the external screw occurred in 2 cases, which were cured after anti-inflammatory and symptomatic dressing change. Long-term skin care, such as symptomatic dressing change, is needed around the external screw, which affects the appearance to some extent after the operation, leading to psychological repellence in a small number of patients, which requires patient guidance and explanation by medical staff and close follow-up to guide their recovery process.
Through reviewing the treatment of clavicle fractures in this paper, the authors concluded as follows: ① Percutaneous external locking plate fixation can effectively avoid further damage to the local blood supply of the fracture, and external elastic fixation stimulates callus regeneration and promotes fracture healing. ② Percutaneous external locking plate fixation can effectively reduce the possibility of clavicular epithelial nerve injury by using small longitudinal incisions with nail holes combined with the protection from the guide. ③ Percutaneous external locking plate fixation effectively reduced the nerve stimulation caused by the friction between the plate and the supraclavicular nerve after the open reduction and fixation of the clavicle fracture in the first-stage. ④ Particularly, there is no need to hospitalize and re-operation to cut the skin in the second phase of the removal of internal fixation, reducing the pain of the second operation and the patient's medical expenditure, and more importantly, avoiding the possibility of abnormal skin sensory function in the shoulder and upper chest due to the supraclavicular nerve injury caused during the removal of internal fixation.