Introduction
There is an increase in prevalence of upper back pain, particularly in the youth or young adult.1 High-velocity low-amplitude (HVLA) manipulation has been a common treatment approach for pain reduction in back and neck complaints.2 Manipulation of the spine has been demonstrated to be a more effective treatment compared to prescription nonsteroidal anti-inflammatory drugs.3
A fracture of the clavicle represents 5-10% of all orthopedic fractures.4 The nonunion rate has been reported to be as high as 20-30%4. Treating without surgery may result in marginally substandard functional outcomes compared to surgery.4
Nerve entrapment typically occurs in individuals active in recreational and occupational activities. This typically occurs in the jugular foramen due to tumor or lymph node biopsy. However, certain injuries such as stretch /traction injury and direct trauma can lead to entrapment as well.5 This patient suffered an injury to the nec and clavicle that resulted in a non-union fracture of the clavicle and spinal accessory nerve entrapment. This type of entrapment can then lead to atrophy of the sternocleidomastoid and trapezius. Common treatments for such an entrapment include physical therapy and even surgical intervention when indicated in severe cases.5,6 Park et al. discussed successful injection of isotonic saline provides relief of symptoms related to spinal accessory nerve entrapment.7
When a nerve injury is suspected, the patient may experience pain, weakness, or paresthesia, with the lack of any known bone, soft tissue, or vascular injury.8 An injury to the accessory nerve may result in mild to moderate functional disability.8 The spinal accessory nerve (SAN) is a motor nerve with cranial and spinal components.8 The cranial portion of the nerve develops for the nucleus ambiguous, and the spinal portion of the nerve comes from the anterior horn cells of the upper 5 cervical segments.8 The accessory nerve exits the jugular foreman and divides into two separate nerves, the spinal portion of the nerve is referred to be the spinal accessory nerve. The SAN innervates the sternocleidomastoid (SCM) and the trapezius muscle on the same side to provide motor resource to the muscles. The SAN will pierce the SCM and travel posterior to the muscle and arrive at the posterior triangle of the neck where it will become more superficial.8
There are 3 components of the trapezius muscle. The upper portion of the trapezius will elevate the scapula,9 while the middle portion will retract, and the lower portion will depress the scapula.9 The upper and lower portion of the trapezius work together to rotate the scapula, superiorly, to enable shoulder abduction above the horizontal plane.9 If there is a nerve injury to the SAN it may cause shoulder pain and limited shoulder abduction.9
Currently, there are no published manuscripts reporting successful conservative treatment of spinal accessory nerve entrapment due to the initial trauma and result an old midclavicle malunion fracture. Therefore, the purpose of this article is to describe conservative chiropractic management of an adult with spinal accessory nerve entrapment due to a malunion fracture of the midclavicle.
Case Report
A 21-year-old male sought care for upper and mid back pain. He reported the symptoms at a 4/10 at rest and a 4/10 during activity using a numeric rating scale. He felt the mechanism of complaint was due to prolonged sitting. The symptoms began approximately 2 weeks prior to his first visit. Exercise and prolonged sitting were reported as aggravating factors. The patient reported lifting, sitting, and working out at the gym as his activities affected daily living, while certain movements, stretching, and other certain exercises were palliative factors. His past history included a broken right clavicle in 2016, with no surgical intervention.
Range of motion was within normal limits in the cervical, thoracic, and lumbar spine. However, the range of motion of the right shoulder was restricted with internal and external rotation without pain. There was noticeable mild (4/5) muscle weakness of the right supraspinatus, trapezius, and SCM. All upper and lower extremity reflexes, motor strength, and sensation were within normal limits. Postural changes noted was anterior head translation and low right shoulder. Foraminal compression test, Jackson’s Compression test, Maximum Compression test, Cervical distraction test, and shoulder depression test were all negative. Codman’s drop arm, and supraspinatus test was negative bilaterally. Impingement sign was positive on the right for ipsilateral shoulder pain and negative on the left. Visual inspection of the area demonstrated mild atrophy of the right upper and middle trapezius with functional hyperkyphotic upper thoracic spine and an apparent deformity of the right clavicle. Scapular winging was negative bilaterally. Muscle spasm was noted in the SCM on the right. Trigger points were documented in the parathoracic bilaterally, and the right upper and mid trapezius. The diagnosis of injury to the spinal accessory nerve on the right side, muscle spasm, and segmental and somatic dysfunction of the cervical and thoracic spine.
A portion of the initial chiropractic management of the patient as a review of findings and an order of imaging to the right clavicle to determine if there was a malunion and if the patient was a candidate for chiropractic treatment. Imaging of the right clavicle demonstrated a malunited mid clavicle fracture with mild diastasis of the acromioclavicular joint. The latter represents old changes of previous acromial clavicular joint strain. The patient’s treatment began with instrument assisted manipulation of the thoracic spine with mechanical massage performed on the thoracic paraspinals and trapezius muscles. Subsequent visits the patient received diversified manipulations to the cervical and thoracic spine with manual therapy performed on the upper, middle trapezius and the SCM. Additionally, the patient’s treatment plan incorporated active care to treat the complaint area.
He was evaluated for rehabilitation using the selective functional movement assessment (SFMA). The results demonstrated an insufficient cervical rotation during the exam, not meeting the normal 80o bilaterally. The patient was then asked to lay down in the supine and again perform active cervical rotation. At this point, the patient could actively reach the required 80o of cervical rotation, thereby establishing a movement diagnosis of postural stability and motor control dysfunction. Postural stability and motor control dysfunction is a diagnosis that indicates a movement dysfunction that changes with posture. With this patient, we had someone who could not actively rotate their cervical spine when standing but could easily do so lying down. The next step in the patient’s rehabilitation treatment would be to establish then which neurodevelopmental position allowed for the most challenging execution of the task while still performing the full range of motion.
The second diagnosis obtained from the SFMA evaluation was a bilateral hip extension mobility dysfunction. This conclusion was drawn since there was minimal difference between active and passive hip extension testing.
From these diagnoses, we decided that exercises would be the preferred intervention for the cervical spine stability and motor control dysfunction, while stretching and joint mobilization would be the preferred intervention for the hips.
After approximately 6 weeks (about 1.5 months) of treatment with HVLA, the patient upper/mid back pain resolved (pain reported at 0/10). His following exam demonstrated resolution of the weakness of the right supraspinatus, trapezius, and SCM. Additionally, there were no visible signs of atrophy of the upper or mid trapezius muscle on the right. He reported he completed the previously affected ADLs with no limitations due to discomfort. During care, no adverse effects were reported.
Discussion
The spinal accessory nerve is the cranial nerve (CNXI) that provides innervation to the sternocleidomastoid and trapezius muscle.10,11 Therefore, a direct injury to the spinal accessory nerve can lead to dysfunction of the sternocleidomastoid and the trapezius muscle. In injury to the spinal accessory nerve (SAN) can lead to pain in the shoulder and upper back. The case of a 21-year-old male with spinal accessory nerve SAN entrapment due to a malunited midclavicular fracture offers valuable insight into the potential for chiropractic and conservative care in managing such injuries. While spinal accessory nerve entrapment is rare, the patient’s presentation and successful treatment highlight several key considerations. The patient responded well to the combination of high-velocity low-amplitude (HVLA) manipulation, manual therapy, and an active rehabilitation program. The complete resolution of the patient’s mid back pain and shoulder dysfunction within 6 weeks emphasizes the effectiveness of conservative management for SAN entrapment. The use of HVLA for spinal adjustments and soft tissue manipulation, combined with rehabilitation focused on functional movement, aligns with existing literature on the management of neuromuscular injuries, which supports spinal manipulation as an effective method for improving pain and range of motion in cases of nerve entrapment and postural dysfunction.1 A treating physician should be aware that numerous studies have outlined that spinal accessory nerve entrapment can lead to myofascial pain syndrome leading to cervical, upper back, and shoulder discomfort.12
The presence of SAN entrapment in a progressive form can lead to axonopathic lesion with axonal degeneration.10 If an individual has SAN entrapment for a prolonged period, this can cause clinical manifestations of lower motor neuron lesions presenting as muscle wasting and mild weakness without scapular winging.10,11 A more chronic the SAN neuropathy may mean the presence of chronic upper trapezius pain. The initial muscle weakness observed in the supraspinatus, trapezius, and sternocleidomastoid muscles suggests the SAN entrapment may have ramifications on shoulder stability and function leading to visual shoulder drooping and asymmetrical neckline.12 Since the SAN provides motor innervation to these muscles, the malunion of the clavicle contributed to chronic irritation and entrapment of the nerve, leading to muscle atrophy and functional limitations, such as difficulty with overhead movements. The patient’s recovery, marked by the absence of pain and atrophy, indicates that the combination of soft tissue work, active rehabilitation and chiropractic manipulation can restore function in cases where nerve irritation is the primary cause of the dysfunction.
The SFMA evaluation of postural stability and motor control dysfunction identified during the patient’s rehabilitation phase provides an important perspective on how neuromuscular control is influenced by both static and dynamic posture. The patient’s inability to perform cervical rotation while standing, but his capacity to do so while supine, suggests a need for targeted postural retraining and motor control exercises in addressing SAN injuries. This finding emphasizes the importance of comprehensive functional assessments in the rehabilitation of nerve injuries, as postural compensations can mask underlying neuromuscular dysfunction. Currently there does not appear to be a specific conservative treatment for SAN entrapment. This study focused on the conservative chiropractic treatment for a patient with symptomatic spinal accessory nerve entrapment.
Limitations
The limitations of this paper are that this is a case report of a single patient, SAN entrapment may present in a different manner for other patients depending on severity and entrapment location. Therefore, the findings of this case may not be generalized to other cases. The patient experienced midback pain after prolonged sitting. He was unable to complete overhead exercises without discomfort. The diagnosis of spinal nerve entrapment could be more conclusive with an EMG; however, we did not obtain one due to the patient’s improvement. The patient also may have had a secondary right shoulder impingement. The shoulder impingement may have been inadvertently addressed in the management plan to reduce the patient’s overall symptoms. Further research should be considered on the use of conservative therapies in patients with upper mid back pain with spinal accessory nerve entrapment due to a malunion of a previous midclavicular fracture.
Conclusion
This case report demonstrates the complete resolution of the mid back complaint in an adult male patient with associated spinal accessory nerve entrapment due to a malunion of a previous midclavicular fracture with HVLA, manual therapy, and active rehabilitation.
This case raises significant questions about the broader applicability of chiropractic care for SAN entrapment and other nerve-related injuries. Future research should focus on the use of conservative therapies, such as spinal manipulation, in treating nerve injuries associated with orthopedic conditions, particularly malunited fractures. Further studies involving larger patient populations and the use of diagnostic tools like EMG could help refine treatment protocols and offer more generalized insights.