Summary of proximal junctional tether techniques from clinical outcomes studies.
Study | Tether Technique |
Pham et al32
Alluriu et al27 | A No. 2 Ethibond double filament suture was used to create a modified locking Krackow weave at both ends of a cadaveric semitendinous tendon graft. This graft was then passed between the spinous processes from 1 level above the UIV to 1 to 2 levels below the UIV. The ends of the Ethibond suture were then tied together alone or tied together over a crosslink. |
Buell et al28
Buell et al29 Line et al31 Rabinovich et al33 | Two different techniques were used. (1) A high-speed drill was used to create holes through the base of the spinous processes at the UIV+1 and UIV-1. A polyetheylene Mersilene tape on a blunt needle was passed through the holes created in the UIV+1 and UIV-1 spinous processes and tied securely. (2) A high-speed drill was used to create a hole through the base of the spinous processes at the UIV+1. A polyetheylene Mersilene tape on a blunt needle was passed through the hole created in the UIV+1 spinous process. The tether was tied to a crosslink placed spanning the rods between UIV-1 and UIV-2. The crosslink was distracted caudally to tension the tether and secured to the rods. |
Iyer et al30 | A 5-mm Mersilene tape on a curved needle was passed through the spinous process of the UIV+1 (Figure 1). A drill was used to create a hole through the spinous process if the needle could not be readily passed. The tether ends were then passed around the spinal rods below the pedicle screws at the UIV in a loop fashion, tensioned manually using a slip knot, and tied. This process was repeated, placing the tape through the spinous process of the UIV and securing the tape below the pedicle screws at the UIV-1. |
Rabinovich et al34 | The VersaTie tether system (NuVasive) was used (Figure 2). A high-speed drill was used to create a hole through the base of the spinous process at the UIV+1 (and in some cases also at the UIV+2). A polyetheylene-terephthalate tape on a blunt needle was passed through the interspinous ligament between the UIV and UIV-1, then either passed through the spinous process at the UIV+1 alone or woven through UIV+1 and UIV+2, then passed back through the interspinous ligament between the UIV and UIV-1. The tether ends were then each passed through supplied tether rod connectors, which were then attached to the rods between the UIV and UIV-1 or between the UIV-1 and UIV-2. The VersaTie tower was then used to tension the tethers before final fixation of the tether to the connector device. |
Rodnoi et al35 | A towel clamp was used to create a hole through the base of the spinous process at the UIV+1 (Figure 3). A polyethylene suture tape was passed through the spinous process at the UIV+1, and the ends of the tape were then tied over a crosslink placed spanning the rods between the UIV and UIV-1. A compressor was then used to distract the crosslink in order to tension the tape before the connector was final tightened. |
Zaghloul et al41
Rodriguez-Fontan et al36 | A 5-mm-wide Mersilene tape was passed through or looped around the supra-adjacent level spinous process (UIV+1), then looped in a figure-of-8 around the infra-adjacent spinous process (UIV), then tied to the rods below the screws at the UIV or tied to a crosslink attached to the rods between the UIV and UIV-1. |
Safaee et al37
Safaee et al38 | The Medicrea tether system was used (Figure 4). A high-speed drill was used to create holes through the base of spinous processes at UIV, UIV+1, and UIV-1. A soft sublaminar cable was passed through these holes in a mirrored weave pattern. Two cables were used (one on each side) and were pulled tightly to achieve the desired tension. The cables were then locked onto the rods using the supplied connectors. |
Viswanathan et al39 | The Jazz system (Implanet America) was used. Bilateral hemilaminotomies were performed to widen the intralaminar spaces proximal and distal to the UIV+1 laminas with a power burr and Kerrison rongeur. The underlying ligamentum flavum was removed using Kerrison rongeurs until the underlying dura was exposed. The 2 braided polyester sublaminar bands were then carefully passed under the lamina from inferior to superior. Neuromonitoring was utilized. The sublaminar bands were connected to the rods at the UIV level and hand-tensioned using a tensioner device. |
Yagi et al40 | Ligamentum flavum proximal and distal to the UIV lamina was partially removed using a Kerrison rongeur or high-speed drill (Figure 5). A 5-mm polethylene sublaminar band was then passed under the lamina of the UIV+1. The tether was attached to the rods bilaterally at a level distal to the upper-most pedicle screws with a torque of 200 Nm using a tape tighetener. |
Abbreviation: UIV, upper-most instrumented vertebra.