Neurophysiological Monitoring in Shoulder Reversal and Revision Surgery
September 04, 2024
Shoulder reversal and revision surgeries are complex procedures that require precision, especially when addressing complications from previous implants. These surgeries aim to improve joint function and relieve pain by correcting mechanical complications of joint prostheses. However, the success of these surgeries heavily depends on intraoperative monitoring and real-time decision-making to prevent nerve damage and other complications.
Case Study Overview: The Challenges of Shoulder Reversal and Revision Surgery
The patient, a 68-year-old male, standing 6 feet tall and weighing 190 pounds, presented with arm and neck pain due to the failure of a hardware implant in his right shoulder. The patient had a history of diabetes, hypertension, and a previous shoulder surgery. He was diagnosed with a failed hemiarthroplasty (an orthopedic surgical procedure that replaces half of a hip joint with an artificial surface) with a resurfacing implant, as well as medialization of the glenoid with retroversion. Given these complexities, the surgical team decided to proceed with a shoulder reversal and revision surgery to address the mechanical complications and improve the patient’s quality of life.
The Role of Neurophysiological Monitoring
During this intricate procedure, the surgical team employed several neurophysiological monitoring modalities, including Somatosensory Evoked Potentials (SSEPs), Motor Evoked Potentials (MEPs), Electromyography (EMG), and Train of Four (TOF) for depth of anesthesia. These tools are crucial in providing real-time feedback about the patient’s neurological status, allowing the surgical team to make immediate adjustments to prevent nerve damage.
Intraoperative Complications and the Importance of Real-Time Monitoring
As the surgery progressed and the joint was prepared for the new hardware, a significant issue arose: The right median SSEP, which monitors the function of the median nerve, began to show significant attenuation—a decrease in the signal that indicates potential nerve compromise. This attenuation correlated with decreased responses in the right hand MEPs (specifically the first dorsal interosseous (FDI) and abductor pollicis brevis-adductor pollicis (APB-ADM) muscles), signaling that the median nerve was at risk.
The surgical team immediately informed the surgeon, who quickly took corrective action. He decided to remove the patient’s arm from the spider device used to stabilize it during surgery and loosen the wrapping around the wrist. Within two trials, the right median SSEP response returned to baseline amplitude, and the affected MEPs were also back to within normal limits. This quick intervention likely prevented significant nerve damage and other serious complications.
The Risks of Unmonitored Procedures
Without real-time feedback from monitoring tools, the surgeon might have continued with the procedure without realizing the median nerve was being compromised. This could have led to several severe complications, including:
- Nerve Ischemia: Continued compression of the median nerve could have restricted blood flow, leading to ischemia, or a lack of oxygen, which can cause nerve tissue damage.
- Peripheral Nerve Damage: Prolonged compression or stretching of the median nerve could result in neuropraxia (temporary nerve block) or even axonal injury, which could cause prolonged recovery or permanent deficits.
- Compartment Syndrome: Excessive pressure within the muscles could lead to compartment syndrome, a painful condition that occurs when pressure within the muscles builds to dangerous levels, reducing blood flow and leading to tissue damage.
- Functional Impairment: Nerve damage could result in long-term functional impairment, affecting the patient’s ability to use the affected arm and hand.
- Post-Operative Complications: Nerve damage could lead to chronic pain, sensory disturbances, and significant functional limitations, potentially requiring further surgical intervention.
Ensuring Safe and Effective Shoulder Surgery
This case demonstrates the essential role of neurophysiological monitoring in shoulder reversal and revision surgeries. By providing real-time feedback, these monitoring tools enable surgeons to detect and correct issues immediately, reducing the risk of nerve damage and other complications. For patients undergoing complex procedures like shoulder revision surgery, neurophysiological monitoring is not just an added precaution—it is a critical component of the surgical process that can significantly impact outcomes.
For surgeons and patients alike, intraoperative monitoring ensures that potential complications are identified and addressed before they can lead to long-term damage, ultimately resulting in safer surgeries and better outcomes.
For more information on the benefits of neuromonitoring and its role in enhancing patient care, please contact us or sign up for our newsletter.
