A woman aged 57 underwent cervical implant surgery due to an unrepaired cervical spine fracture. She was suffering from constant neck pain after the surgery. After eight years she experienced an infected skin rash on her plantar side. It was which was later identified as a possible metal allergy. The dentures made of metal were substituted by ceramic ones. The rash on her skin persists for four more years following it was treated using cervical implant removal. The rash on her skin as well as her neck pain diminished at the same time. This improvement was synchronized and is a strong indication that the neck pain may have been due to an allergy to the cervical implant. This article discusses an example of an implant-related allergy to the posterior part of the cervical spine that was accompanied by neck pain and a plantar skin rash several years after surgery.
Introduction
A metal allergy can be a common complication after surgery to fix instruments [11. In a research conducted by Kitagawa and colleagues. that involved 925 patients, who underwent allergy patch testing to determine if they had an allergy history that was asymptomatic of the presence of metal allergy, dental allergies were identified as the primary cause of metal allergy symptoms, and they were observed in 392 of 925 (42.4 percent) patients [22. There are also few cases of metal allergy following spinal surgery for instrumentation [3-83-8]. Additionally, allergic reactions, although smaller in numbers were reported following implanting titanium alloys [1,6-81 – 8.
The pain of neck after post-cervical spine surgical procedure is a common complaint of a muscle source [9]. Moreover, chronic neck pain can be found in 2% to 2percent of patients [1010. On the other hand neck pain can be alleviated through spinal bone fusion at surgery’s site (1111.
We discuss the case of a skin rash that was diagnosed as a metal allergy . It was noticed eight years after spinal titanium implant surgery. The condition ameliorated four years later after spinal implant removal. The neck pain that was intractable and persist since the cervical implant surgery also decreased following its removal. The simultaneous improvement of conditions strongly indicates that remaining neck pain was caused by some kind of allergy that was caused by the implant. This case report highlights the frequent allergic reactions that occur following the spinal implant surgery.
Case Presentation
A woman aged 57 was thrown down the stairs at home and struck her face with a hefty force on the walls. A doctor nearby diagnosed a fracture of the nasal bone and treated it in a conservative manner. The patient then visited the orthopedic specialist at her local hospital for neck pain which persisted. She was sent for an orthopedic appointment on 9th day following the injury.
The patient had no neurologic issues at the time of the initial examination However, cervical pain became evident in the body’s movements. The neck pain did not ease by wearing the neck collar. A simple cervical spine X-ray revealed an anterior slip of C6 on C7, an increased C5-6 interspinous space and perched C6-7 facet and widening of the C6-7 spinal foramen (Figure 1A). MRI cervical spine revealed minor C5-6 and C6-7 disc bulges in the cervical disc, but there was no sign of spinal canal damage and cervical cord injuries (Figure 1B). CT revealed subluxation as a result of a fracture in the C6/C7 left facet joint (Figure 2.). It was determined that the patient had a deformed C6 fracture, and surgery using the titanium alloy implant was carried out in September of 2008. (Figure 3.).
We first tried performing fixing of the C5-C7. We found it difficult to install screws at all levels, we decided to perform C5-C6 fixation on the right side using the lateral mass screw and fixing the left C6-C7 with an lateral mass screw and pedicle screw to achieve stable stabilization (Figure 3.). Following surgery the patient’s post-operative neck pain decreased, however the chronic pain that required daily non-steroidal anti-inflammatory medications (NSAIDs) persists even after the bone fuse.
Eight years after the instrumentation procedure the rash of skin appeared on her sole foot. It was identified as palmoplantar pustulosis. It was then treated with phototherapy by a dermatologist however, the rash didn’t disappear. The dermatologist concluded that the reason for the rash on the skin was due to a metal allergy due to metal dentures. He conducted tests on the patch as well as an analysis of the lymphocytes. These test confirmed that he had an allergy to metals. All her dentures made of metal were removed and replaced by ceramic ones. The patient’s skin rash was not better however, for a further four years. The persistent skin rash led the dermatologist to think the root of the allergy may be related to the cervical implant of the patient.
The active Plain cervical spine X-rays confirmed the stability of the patient’s spine fusion level, which allowed implant removal (Figures 4 5, 4). The patient was treated with the removal of her implant at 12 years old after the first procedure. Complete bone fusion and stability of the fixing site were verified intraoperatively.
Following the removal of the implant the rash on the sole was less (Figure 6) which indicates that the root of the allergy was due to the cervical implant. In addition her neck pain significantly decreased.
Discussion
A high rate of allergies to metals that are caused by contact is reported with various metals being the reason for the allergic reactions with the following percentages of nickel up to 24.4 percent; cobalt: 8.8 percent; chromium 5.9 percent and titanium 0.2-3 1 . Thus, the introduction implanted titanium in the last few years has led to implants less prone to allergies be present than when chromium and cobalt were the most commonly employed. Recently, according to information that were collected following the implant arthroplasty procedure in around 1,000 patients, the risk of metal hypersensitivity caused by implants made of metal was as low as 1 percent.
A group of experts from around the world has developed the following diagnostic procedures to establish a hypersensitivity to metal the presence of an eruption that is over the implant, confirmation of an allergic reaction to the metal element by the patch test and complete elimination of symptoms following the removal of the implant, and persistent dermatitis that can develop weeks or months after the implant’s use [1212. The diagnosis of an implant allergy is made through a patch test when an eruption on the skin is found to be present, and removal is vital to the treatment and the final diagnosis.
In a study conducted by Mody and colleagues. The biopsy samples of surrounding tissues around spinal implant of patients who underwent the lumbar spinal removal of hardware for the treatment of pseudoarthrosis, prominent hardware and fusion extension , showed reaction of the soft tissues. Metal deposits that were black were found in nine of the samples and seven of them showed an inflammation foreign-body reactions [13]. In a separate study by Kasai and colleagues. which included 46 patients who had titanium alloy spinal implants, increased levels of metal in hair and blood were detected in around 1/3 of the patients, with the average time of 5.1 years following spinal implant installation. It was believed there was a possibility that some iron in the implant had disintegrated and could cause symptoms in distant organs across the entire body].
Immunologically, implant allergy results from autoimmunity/inflammatory reactions and type 4 delayed hypersensitivity reactions [15-17]. The trigger of these hypersensitivity, autoimmune or inflammatory reactions is caused by metal-bound proteins that are recognized by immune systems, or through free radicals that are generated by sulfur binding to metal inside mitochondria and enzymes cells, and proteins in the mitochondria [15-1715-17.
Post-spinal-implant-metal allergy is not a common occurrence even though it is a frequent cause in spinal implant-related reactions. A few cases of clinical spinal implant-related allergy are published in the literature [3-83-8. The chronic pain that occurs in the area of the surgery noted in one instance located in the cervical area and three cases of thoracolumbar pain were also reported. The pain decreased in all cases following the surgical procedure was completed.
Neck pain that is chronic caused by a cervical implant quite frequent [10], and it has been reported that a reduction in pain after implant removal is reported [1818. The most typical sign of allergy to implants is chronic pain, which can be seen in the days following surgery [1920]. In this patient, there was hard to differentiate the difference between persistent neck discomfort as well as the symptoms of allergy that are seen in a few neck implant patients. The chronic pain that occurs after spinal implant surgery might result from instability as a result of a weak bone fusion at the surgical location [11] and the patient who suffers from this situation will experience significant improvement in pain after the removal of the implant [2021.
In our instance, while the generalized neck pain improved immediately after surgery, the chronic neck pain that required medication remained regardless of whether the bony cervical joint occurred. It was thought to be a result of the surgery. A rash of skin on the sole surface appeared 8 years after surgery which indicated the presence of an allergy to metal in the patient. This case showed an improvement in pain immediately following implant removal surgery , even in being able to show spinal instability caused by inadequate bone fusion. The significant pain relief suggested that this relief was not solely due to the removal of the implant itself, but also an improvement in the severity of implant allergic symptoms.
Conclusions
We have reported a rare instance that had a reaction to metal that occurred following cervical implant surgery that caused constant neck pain. The removal of the implant did not only alleviated the skin rash, it also alleviated the persistent neck pain that remained from the initial implant surgery. The study suggests one must be aware of the possibility of metal allergy if patients complain of refractory neck pain that persists after implant surgery. In such instances the possibility of a patch test or the lymphocyte transformation test must be taken into consideration.
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