Migration of the Kirschner‘s wire into the spine as a cause of long-lasting neurological problems

This is an unauthorised machine translation into English made using the DeepL Translate Pro translator. The editors do not guarantee that the content of the article corresponds fully to the original language version.

Dear Editor,

Kirschner wire (K-wire), one of the most widely used osteosynthetic implants, is characterized by its ease of use, low cost, and tissue friendliness. Nevertheless, it also carries significant disadvantages. Instability and the possibility of migration from the original location are among the main risks associated with the use of K-wires. When their extraction is not performed in a timely manner, there is a risk that the K-wires will leave the site of insertion and can reach any part of the body. Migration of K-wires to the intraspinal region is rarely described. However, when it does occur, the clinical symptoms are extremely varied, causing considerable diagnostic confusion. Let us present a case of K-wire migration into the spine, which was the hidden cause of the patient's long-term neurological problems.

A 36-year-old patient with no associated diseases consulted his general practitioner for long-term problems associated with neck stiffness and neck pain with irradiation between the shoulder blades. After a neck X-ray was performed, which showed the presence of foreign contrast structures in the cervicothoracic isthmus, the patient was referred to a higher referral unit for follow-up and comprehensive management of his condition (Figure 1).

On further investigation, palpable painless resistance was noted in the lower left neck. As the patient had undergone osteosynthesis of the left clavicle using two K-wires 16 years ago and their subsequent extraction was unsuccessful, migration of the osteosynthetic material was suspected. Complementary CT scanning confirmed the malposition (Figure 2). One of the wires was extending transversely through the epidural space ventrally in the spinal canal transforaminally at the level of C6 -⁠ on the right through the foramen neurale C5/6 and on the left through the foramen neurale C6/7. The second K-wire was placed just prevertebral at the level of C7. Initial neurological examination showed no pathological findings.

Electrical extraction of the migrated K-wires was performed using a left anterolateral approach and an accessory incision behind the sternocleidomastoid muscle. The dura mater was not sutured. Postoperatively, there was impaired abduction in the left shoulder joint, probably due to compression of the truncus superior brachial plexus on the left with innervation from the C5/6 roots. There were paresthesias and hypesthesias on the left forearm, hand, and fingers, which corresponded with impaired sensory innervation in the C6-C8 dermatomes. Despite these neurologic manifestations, the patient was otherwise free of significant problems in the immediate postoperative period. He was discharged on the third postoperative day.

On the 6th day after discharge, the patient presented with fever and painful swelling on the left side of the neck. At the same time, he reported new-onset paresthesias in the anterolateral part of the neck on the left side and on the face in the mandibular area on the left, suggesting irritation of probably the nervus transversus coli and the nervus auricularis magnus. CT scan confirmed the presence of a left-sided parapharyngeal abscess. The condition was managed acutely by drainage of the abscess via a colic mediastinotomy. After evacuation of the abscess, the patient's condition promptly improved. There was no phonation or swallowing disorder. The wound was left for secondary healing, was dressed daily and the patient was discharged after two days for home care.

In the subsequent course, the wound closed within 3 weeks after standard dressing therapy. Pain on the left side of the neck and face resolved within a few weeks of abscess evacuation. Subsequently, the patient underwent rehabilitation for paresis of the m. deltoideus and m. supraspinatus on the left, which gradually resolved over the course of a year. The impairment of sensation of the lateral neck in terms of hypesthesia persisted for a total of 2 and a half years, regressing completely over time except for the sites of the incision scars themselves. Paresthesias in C6-C8 dermatomes practically completely corrected within 16 months. To the present time, only the hypesthesia on the ulnar side of the little finger of the hand on the left persists, where the condition has not changed even after 4 years. Residual hypesthesia at the site of scars from surgical approaches to the neck and minimal hypesthesia of the little finger of the left hand are tolerated by the patient without limitations in everyday life.

The Kirschner wire was introduced into clinical practice in 1909, originally for skeletal traction of the long bones of the extremities [1]. However, its use for direct fixation of fragments in the fracture line did not begin until 1931 [2]. Despite the simplicity and effectiveness of K-wires, however, their drawbacks were quickly discovered. As early as 1939, Selig warned against the use of K-wires in femoral neck fractures because of their lack of stability [3]. The first case of migration was described in 1943 in the form of a K-wire that became dislodged from the clavicle and entered the lung [4]. Exceptionally, migration of osteosynthetic material into the spine has also occurred and was first reported by Norrell et al. [5].

In Czech and Slovak sources, this complication has been mentioned only in the work of Pribáň and Toufar [6]. The authors report a patient after stabilization of acromioclavicular (AC) luxation using two K-wires and serclage. In their case, both K-wires were released from the clavicle, with one penetrating the spinal cord at the C7/T1 level. Severe sequelae with limitation of the patient's motor, sensory and sexual functions persisted after extraction.

However, foreign authors who have reviewed published case reports with intraspinously migrated K-wires describe more favorable outcomes. The largest literature series were collected by N'da et al. and Furuhata et al. [7,8]. Collectively, they present an analysis of the literature in 16 patients with this complication. Coincidentally, they were all male. The initial intervention in most of them was stabilization of the AC joint and clavicle with K-wires or thin pins.

Extraction was indicated in all of them and was performed without complications in all of them. Despite the high-risk site, complete regression of symptoms occurred in up to 14 patients and only one patient had severe permanent sequelae. K-wires and pins were placed in the spinal canal 14 times, with up to 11 times the metal material penetrating intraspinously through the foramen neurale. In the spinal canal, the migrated material penetrated the spinal cord on five occasions. It is noteworthy that up to four of these patients had a complete correction of the condition.

These papers show that as long as there is no stab injury to the spinal cord, migrated implants are relatively safe even in the spinal canal. They also emphasize that despite the unsafe location of loose implants, the symptoms are extremely varied.

Although intraspinal migrated osteosynthetic material is a rare complication, the eventual clinical manifestations range from patient disability, to very non-specific pain, to fully asymptomatic patients. Extraction of the material falls within the neurosurgeon's expertise and is indicated in any case.

The practical lessons from the above case reports can be summarized as follows. First of all, in the management of nonspecific neck and upper back pain, it is important to recall the importance of a correctly taken patient history, not excluding data on orthopedic and trauma surgeries in the shoulder region. As far as imaging examination methods are concerned, it is still wise to start with a conventional X-ray. Choosing MRI at the outset in this case could have untimely medical and legal consequences.

Conflict of interests

The authors declare that they have no conflict of interest in relation to the subject of the paper.