Case Reports / Journal of Clinical Neuroscience 22 (2015) 1365–1366
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O-arm failure traps patient prone on a Jackson table Sergey Pisklakov b, John K. Houten a,⇑, Murray Echt a, Angelika Kosse b, Apolonia E. Abramowicz b a b
Department of Neurosurgery, Albert Einstein College of Medicine, Yeshiva University, Montefiore Medical Center, 111 East 201st Street, Bronx, NY 10467, USA Department of Anesthesiology, Albert Einstein College of Medicine, Yeshiva University, Montefiore Medical Center, Bronx, NY, USA
a r t i c l e
i n f o
Article history: Received 4 March 2015 Accepted 7 March 2015
Keywords: Image-guided surgery Navigation O-arm Patient safety Pedicle screw Spinal surgery
a b s t r a c t The O-arm Surgical Imaging System (Medtronic Sofamor Danek, Memphis, TN, USA) is an increasingly popular tool for spinal surgical procedures that allows for intraoperative acquisition of multi-dimensional spinal imaging that can be used either to confirm placement of spinal instrumentation or to guide spinal screw placement in conjunction with a navigation system. The machine is typically placed open from the side of the patient positioned prone on the Jackson spinal table (Mizuho OSI, Union City, CA, USA) and then closed to complete a ring around the patient to acquire images. A failure of the O-arm opening mechanism can lead to a patient becoming effectively trapped within the device with limited physician access to the patient’s body, a situation that may be remedied by using a manual opening procedure. This report highlights a patient safety issue encountered when a mechanical failure of the O-arm occurred and one of the two tools required for its manual opening was missing. We describe the improvised method employed to successfully open the device. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction The O-arm Surgical Imaging System (Medtronic Sofamor Danek, Memphis, TN, USA) is an intraoperative tool for precise placement of spinal instrumentation and to verify hardware positioning. The technology aids in achieving a high degree of pedicle screw placement accuracy [1,2]. The radiograph source and detector are contained within a cylindrical bore that can open coaxially, allowing the imaging device to be positioned around a patient, typically on the Jackson spinal table (Mizuho OSI, Union City, CA, USA) which is supported at its ends rather than on a central pedestal. After closure, the device forms a complete ring around the patient [3,4] (Fig. 1). The O-arm allows for emergency manual opening. Failure of the O-arm unlocking mechanism may effectively trap the patient within the device. Two tools are then required: a Tshaped rotor alignment pin and a socket-head wrench (Fig. 2). We report a case of an O-arm opening failure where the emergency wrench could not be found and the device was ultimately manually opened using a conventional tire wrench (Fig. 3).
of the O-arm there are three mechanical wells covered with plastic stoppers, and manual ring opening requires a multi-step procedure using two tools: a T-shaped pin and a lever-type socket wrench (Fig. 1), which are usually stored in a bin on the side of the machine. In our case, only the T-shaped pin was found. The wrench could not be located anywhere within the operating room suites. The on-call representative of the hospital engineering department was called but as the surgery was taking place late in the evening, this associate was not an individual who was
2. Case report A 66-year-old man with a history of prostate cancer presented with bilateral lower extremity weakness. MRI showed T9 metastatic infiltration with severe cord compression. He was positioned prone on the Jackson spinal table for a thoracic laminectomy and spinal fusion with instrumentation. Following exposure, the O-arm was brought in and intraoperative imaging for navigated placement of instrumentation was acquired. Subsequently, a loud mechanical noise was heard from within the O-arm and the ring failed to open. Despite multiple additional attempts using the controls on the device console with a Medtronic hotline representative providing advice on the telephone, the ring remained closed with the patient inside. The manual unlocking procedure was then recommended. On the side ⇑ Corresponding author. Tel.: +1 718 920 7470; fax: +1 718 584 0224. E-mail address: [email protected] (J.K. Houten).
Fig. 1. Intraoperative photograph of the O-arm Surgical Imaging System (Medtronic Sofamor Danek, Memphis, TN, USA) in the closed position around a pronepositioned patient undergoing a lumbar spinal fusion procedure.
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Case Reports / Journal of Clinical Neuroscience 22 (2015) 1365–1366
Fig. 3. A conventional 3=4 inch auto tire wrench was used to open the O-Arm ring in the absence of the manufacturer supplied 3=4 inch lever-type socket-head wrench.
cannot be found, a conventional 3=4 inch lug wrench can be used as a substitute. Fig. 2. The manual O-arm ring opening access point has three mechanical wells that require two tools: a T-shaped rotor alignment pin shown inserted into the designated position (circled), and a 3=4 inch lever-type socket-head wrench shown inserted into the well on the right (arrow).
regularly assigned to the operating room area and he was unable to locate a compatible tool. After studying the image of the missing tool online, we noted its resemblance to a car tire lug wrench, which was ultimately procured and used to open the O-arm (Fig. 2). 3. Discussion Clinicians should be aware that mechanical failure of the O-arm locked in the closed position is possible, leading to a hazardous situation with a patient’s body trapped prone within the ring of the device. As a safety precaution, the O-arm should be used only after it is confirmed that both tools for manual unlocking are in their designated place. In the event that the manufacturer’s wrench http://dx.doi.org/10.1016/j.jocn.2015.03.003
Conflict of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.
References [1] Sembrano JN, Rainier ER, David DW. New generation intraoperative threedimensional imaging (O-arm) in 100 spine surgeries: does it change the surgical procedure? J Clin Neurosci 2014;21:225–31. [2] Houten JK, Nasser R, Baxi N. Clinical assessment of percutaneous lumbar pedicle screw placement using the O-arm multidimensional surgical imaging system. Neurosurgery 2012;70:990–5. [3] Oertel MF, Hobart J, Stein M, et al. Clinical and methodological precision of spinal navigation assisted by 3D intraoperative O-arm radiographic imaging: technical note. J Neurosurg Spine 2011;14:532–6. [4] Tabaraee E, Gibson AG, Krahalios DG, et al. Cone beam-computed tomography with navigation (O-ARM) versus conventional fluoroscopy (C-ARM): a cadaveric study comparing accuracy, efficiency, and safety for spinal instrumentation. Spine (Phila Pa 1976) 2013;38:1953–8.
1365
O-arm failure traps patient prone on a Jackson table Sergey Pisklakov b, John K. Houten a,⇑, Murray Echt a, Angelika Kosse b, Apolonia E. Abramowicz b a b
Department of Neurosurgery, Albert Einstein College of Medicine, Yeshiva University, Montefiore Medical Center, 111 East 201st Street, Bronx, NY 10467, USA Department of Anesthesiology, Albert Einstein College of Medicine, Yeshiva University, Montefiore Medical Center, Bronx, NY, USA
a r t i c l e
i n f o
Article history: Received 4 March 2015 Accepted 7 March 2015
Keywords: Image-guided surgery Navigation O-arm Patient safety Pedicle screw Spinal surgery
a b s t r a c t The O-arm Surgical Imaging System (Medtronic Sofamor Danek, Memphis, TN, USA) is an increasingly popular tool for spinal surgical procedures that allows for intraoperative acquisition of multi-dimensional spinal imaging that can be used either to confirm placement of spinal instrumentation or to guide spinal screw placement in conjunction with a navigation system. The machine is typically placed open from the side of the patient positioned prone on the Jackson spinal table (Mizuho OSI, Union City, CA, USA) and then closed to complete a ring around the patient to acquire images. A failure of the O-arm opening mechanism can lead to a patient becoming effectively trapped within the device with limited physician access to the patient’s body, a situation that may be remedied by using a manual opening procedure. This report highlights a patient safety issue encountered when a mechanical failure of the O-arm occurred and one of the two tools required for its manual opening was missing. We describe the improvised method employed to successfully open the device. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction The O-arm Surgical Imaging System (Medtronic Sofamor Danek, Memphis, TN, USA) is an intraoperative tool for precise placement of spinal instrumentation and to verify hardware positioning. The technology aids in achieving a high degree of pedicle screw placement accuracy [1,2]. The radiograph source and detector are contained within a cylindrical bore that can open coaxially, allowing the imaging device to be positioned around a patient, typically on the Jackson spinal table (Mizuho OSI, Union City, CA, USA) which is supported at its ends rather than on a central pedestal. After closure, the device forms a complete ring around the patient [3,4] (Fig. 1). The O-arm allows for emergency manual opening. Failure of the O-arm unlocking mechanism may effectively trap the patient within the device. Two tools are then required: a Tshaped rotor alignment pin and a socket-head wrench (Fig. 2). We report a case of an O-arm opening failure where the emergency wrench could not be found and the device was ultimately manually opened using a conventional tire wrench (Fig. 3).
of the O-arm there are three mechanical wells covered with plastic stoppers, and manual ring opening requires a multi-step procedure using two tools: a T-shaped pin and a lever-type socket wrench (Fig. 1), which are usually stored in a bin on the side of the machine. In our case, only the T-shaped pin was found. The wrench could not be located anywhere within the operating room suites. The on-call representative of the hospital engineering department was called but as the surgery was taking place late in the evening, this associate was not an individual who was
2. Case report A 66-year-old man with a history of prostate cancer presented with bilateral lower extremity weakness. MRI showed T9 metastatic infiltration with severe cord compression. He was positioned prone on the Jackson spinal table for a thoracic laminectomy and spinal fusion with instrumentation. Following exposure, the O-arm was brought in and intraoperative imaging for navigated placement of instrumentation was acquired. Subsequently, a loud mechanical noise was heard from within the O-arm and the ring failed to open. Despite multiple additional attempts using the controls on the device console with a Medtronic hotline representative providing advice on the telephone, the ring remained closed with the patient inside. The manual unlocking procedure was then recommended. On the side ⇑ Corresponding author. Tel.: +1 718 920 7470; fax: +1 718 584 0224. E-mail address: [email protected] (J.K. Houten).
Fig. 1. Intraoperative photograph of the O-arm Surgical Imaging System (Medtronic Sofamor Danek, Memphis, TN, USA) in the closed position around a pronepositioned patient undergoing a lumbar spinal fusion procedure.
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Case Reports / Journal of Clinical Neuroscience 22 (2015) 1365–1366
Fig. 3. A conventional 3=4 inch auto tire wrench was used to open the O-Arm ring in the absence of the manufacturer supplied 3=4 inch lever-type socket-head wrench.
cannot be found, a conventional 3=4 inch lug wrench can be used as a substitute. Fig. 2. The manual O-arm ring opening access point has three mechanical wells that require two tools: a T-shaped rotor alignment pin shown inserted into the designated position (circled), and a 3=4 inch lever-type socket-head wrench shown inserted into the well on the right (arrow).
regularly assigned to the operating room area and he was unable to locate a compatible tool. After studying the image of the missing tool online, we noted its resemblance to a car tire lug wrench, which was ultimately procured and used to open the O-arm (Fig. 2). 3. Discussion Clinicians should be aware that mechanical failure of the O-arm locked in the closed position is possible, leading to a hazardous situation with a patient’s body trapped prone within the ring of the device. As a safety precaution, the O-arm should be used only after it is confirmed that both tools for manual unlocking are in their designated place. In the event that the manufacturer’s wrench http://dx.doi.org/10.1016/j.jocn.2015.03.003
Conflict of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.
References [1] Sembrano JN, Rainier ER, David DW. New generation intraoperative threedimensional imaging (O-arm) in 100 spine surgeries: does it change the surgical procedure? J Clin Neurosci 2014;21:225–31. [2] Houten JK, Nasser R, Baxi N. Clinical assessment of percutaneous lumbar pedicle screw placement using the O-arm multidimensional surgical imaging system. Neurosurgery 2012;70:990–5. [3] Oertel MF, Hobart J, Stein M, et al. Clinical and methodological precision of spinal navigation assisted by 3D intraoperative O-arm radiographic imaging: technical note. J Neurosurg Spine 2011;14:532–6. [4] Tabaraee E, Gibson AG, Krahalios DG, et al. Cone beam-computed tomography with navigation (O-ARM) versus conventional fluoroscopy (C-ARM): a cadaveric study comparing accuracy, efficiency, and safety for spinal instrumentation. Spine (Phila Pa 1976) 2013;38:1953–8.
