- Email: [email protected]
P97. Clinical outcome in patients undergoing anterior cervical discectomy and fusion with or without direct uncovertebral joint decompression
Proceedings of the NASS 18th Annual Meeting / The Spine Journal 3 (2003) 67S–171S
141S
flexion-extension range of motion of implants was 8 degrees (range 2–12) at L5-S1 and 10 degrees (range 8–18) at L4-L5. Complications occurred in 9% of patients and included vertebral body fracture, transient radicular pain, implant malposition, and transient retrograde ejaculation. Three patients (6%) required reoperation to address complications. No mechanical failure of the implants or loosening was observed. DISCUSSION: Total disc replacement has the potential to replace fusion as the gold standard surgical treatment for degenerative disc disease. Potential advantages of TDR over fusion include avoidance of pseudarthosis, postoperative orthoses, and junctional degeneration. There are no published studies with minimum 1-year follow-up of the PRODISC II prosthesis. Longerterm follow-up of the SB Charite´ prosthesis has been reported, but there are significant biomechanical differences between the two implants, especially with regard to kinematics and constraint. Randomized trials comparing fusion to disc replacement and comparing different TDR implants with long follow-up periods are required to determine to relative merits of the various procedures and implants. CONCLUSIONS: In properly selected patients, lumbar TDR with the PRODISC II has excellent clinical and radiographic results at mean 1.4year follow-up. Patients with single or multilevel degenerative disc disease are candidates for this procedure. Implant malposition and intra-operative fracture resulted in a 6% reoperation rate. DISCLOSURES: Device or drug: PRODISC II lumbar disc replacement. Status: investigational. CONFLICT OF INTEREST: Federico Girardi, MD, Thierry Marnay, MD, stockholders: Spine Solutions, Inc. Thierry Marnay, MD, grant research support: for research staff; board member: Spine Solutions, Inc.
good results, 8.5% reported fair results, and 1.1% reported poor results. In group 2, 28% of the patients reported excellent results, 62% reported good results, and 10% reported fair results. All nonunions reported good outcomes. Postoperative respiratory distress developed in one patient and dysphagia developed in another both from group 1. No other complications were noted. The presence or absence of direct uncovertebral joint decompression and clinical outcome was not statistically significant (p⬎0.05). The use of graft-type, operative level, presence of smoking, and work-related injury in relation to clinical outcome was not found to be significant. DISCUSSION: Satisfactory results were obtained in 90.5% and 90.0% of patients for groups 1 and 2, respectively. Good to excellent results in relieving neck pain and radicular symptoms were obtained in 90% of patients who underwent direct uncovertebral joint decompression and in patients with indirect decompression by distraction and leaving the uncovertebral joint intact. CONCLUSIONS: Indirect foraminal decompression through distraction remains somewhat controversial during ACDF, however sacrificing the uncovertebral joint can increase operative time and potentially increase complication rates. This study demonstrates that ACDF with or without direct uncovertebral joint decompression can provide good clinical results for neck pain with cervical radiculopathy. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
doi: 10.1016/S1529-9430(03)00335-8
P102. Multidirectional stability of a dynamic stabilization system over graf ligamentoplasty: the effect of various posterior stabilizing implants Osamu Shirado, MD1, Yoshihiro Hojo, MD1, Akio Minami, MD1; 1 Hokkaido University, Sapporo, Japan
P97. Clinical outcome in patients undergoing anterior cervical discectomy and fusion with or without direct uncovertebral joint decompression Francis Shen, MD1, Dino Samartzis1, Edward Goldberg1, Howard An1; 1Rush-Presbyterian-St. Luke’s Medical Center/Rush University, Chicago, IL, USA HYPOTHESIS: Anterior cervical discectomy and fusion (ACDF) is an established procedure for the treatment of cervical disc disease. Studies demonstrate that in patients with radiculopathy secondary to impingement from uncovertebral joint osteophytes, direct decompression of the offending lesion provides excellent clinical outcome. However known complications include vertebral artery injury, dural tears, nerve root injury, and loss of biomechanical stability. Other studies suggest that disc space distraction may also play an important role by indirectly decompressing neural elements. We hypothesis that patients the undergo ACDF without direct uncovertebral joint decompression will have similar clinical outcomes to those that undergo ACDF with direct decompression. METHODS: Clinical outcome of 144 consecutive patients (mean 46 years, range 27–83) that underwent ACDF with constrained plate fixation were reviewed at a single institution. Patients with radiculopathy due to herniated disc, spondylosis, or a combination of both refractory to conservative treatment underwent surgery utilizing a standard Smith-Robinson left-sided approach. Ninety-four patients that received direct uncovertebral joint decompression (group 1) were compared to 50 patients without direct decompression but indirect decompression by disc space distraction (group 2). In group 1, 54 one-level and 40 two-level ACDFs were performed. In group 2, 18 and 32 were one-level and two-level ACDFs respectively. The presence of smoking and work-related injuries involved 32.9% and 43.6% of group 1 and 26% and 32% of group 2, respectively. Autologous iliac crest grafts was used in 65 patients, while 79 patients received allograft. Blinded analyses of plain radiographs were conducted (mean, 9.2 months). Clinical outcomes were reported as excellent, good, fair or poor (mean, 15 months) based on Odom’s criteria. RESULTS: Fusion occurred in 95.7% of group 1 and 100% of group 2. In group 1, 27.7% of the patients reported excellent results, 62.8% reported
doi: 10.1016/S1529-9430(03)00336-X
HYPOTHESIS: An expected advantage of Graf ligamentoplasty over spinal fusion is the decrease risk of adjacent-segment morbidity by stabilizing unstable segments without requiring rigid spinal arthrodesis. However, it remains controversial whether the Graf system can be rigid enough to stabilize an unstable spine. Thus, refinement of the Graf system has recently been highlighted in the literature. The purpose of this study was to biomechanically evaluate multidirectional stability of the dynamic stabilization systems using various posterior stabilizing implants. We hypothesized that this system could provide the multidirectional stability for unstable lumbar spines. METHODS: Twelve fresh calf lumbar spine specimens (L2-sacrum) were subjected to compression (100 N), flexion and extension (5 N-m), lateral bending (5 N-m), and rotation (10 N-m). The load-displacement curves were simultaneously measured. Testing of the intact spine preceded testing of the L4-5 destabilized spine (performed by bilateral medial facetectomies), and in each of the following stabilizing treatment groups: Graf ligamentoplasty, Graf with posterior titanium springs between the pedicle screws, Graf with an interspinous coiled artificial ligament, Graf with an interspinous ceramic spacer, and a rigid pedicle screw system. Extensometers were applied to measure the strain in the stabilized (L4-5) and adjacent segments (L3-4). Statistical analysis was carried out using one-way ANOVA. RESULTS: In the flexion and compression, the strain at L4-5 was not significantly different among all the stabilized constructs except the rigid pedicle screw system. During extension, lateral bending, and rotation, Graf ligamentoplasty enhanced with the various posterior implants were more stable than Graf ligamentoplasty alone (p⬍0.05). The construct enhanced with the ceramic spacer was the most stable of the treatment groups (p⬍.05). The posteriorly enhanced systems were more flexible than the rigid pedicle screw system. Furthermore, the strain at the adjacent segment (L3-4) in the posteriorly enhanced constructs was significantly lower than using the rigid pedicle screw system. DISCUSSION: The current study demonstrates that the Graf ligamentoplasty can provide a multi-directional dynamic stabilization for the
141S
flexion-extension range of motion of implants was 8 degrees (range 2–12) at L5-S1 and 10 degrees (range 8–18) at L4-L5. Complications occurred in 9% of patients and included vertebral body fracture, transient radicular pain, implant malposition, and transient retrograde ejaculation. Three patients (6%) required reoperation to address complications. No mechanical failure of the implants or loosening was observed. DISCUSSION: Total disc replacement has the potential to replace fusion as the gold standard surgical treatment for degenerative disc disease. Potential advantages of TDR over fusion include avoidance of pseudarthosis, postoperative orthoses, and junctional degeneration. There are no published studies with minimum 1-year follow-up of the PRODISC II prosthesis. Longerterm follow-up of the SB Charite´ prosthesis has been reported, but there are significant biomechanical differences between the two implants, especially with regard to kinematics and constraint. Randomized trials comparing fusion to disc replacement and comparing different TDR implants with long follow-up periods are required to determine to relative merits of the various procedures and implants. CONCLUSIONS: In properly selected patients, lumbar TDR with the PRODISC II has excellent clinical and radiographic results at mean 1.4year follow-up. Patients with single or multilevel degenerative disc disease are candidates for this procedure. Implant malposition and intra-operative fracture resulted in a 6% reoperation rate. DISCLOSURES: Device or drug: PRODISC II lumbar disc replacement. Status: investigational. CONFLICT OF INTEREST: Federico Girardi, MD, Thierry Marnay, MD, stockholders: Spine Solutions, Inc. Thierry Marnay, MD, grant research support: for research staff; board member: Spine Solutions, Inc.
good results, 8.5% reported fair results, and 1.1% reported poor results. In group 2, 28% of the patients reported excellent results, 62% reported good results, and 10% reported fair results. All nonunions reported good outcomes. Postoperative respiratory distress developed in one patient and dysphagia developed in another both from group 1. No other complications were noted. The presence or absence of direct uncovertebral joint decompression and clinical outcome was not statistically significant (p⬎0.05). The use of graft-type, operative level, presence of smoking, and work-related injury in relation to clinical outcome was not found to be significant. DISCUSSION: Satisfactory results were obtained in 90.5% and 90.0% of patients for groups 1 and 2, respectively. Good to excellent results in relieving neck pain and radicular symptoms were obtained in 90% of patients who underwent direct uncovertebral joint decompression and in patients with indirect decompression by distraction and leaving the uncovertebral joint intact. CONCLUSIONS: Indirect foraminal decompression through distraction remains somewhat controversial during ACDF, however sacrificing the uncovertebral joint can increase operative time and potentially increase complication rates. This study demonstrates that ACDF with or without direct uncovertebral joint decompression can provide good clinical results for neck pain with cervical radiculopathy. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
doi: 10.1016/S1529-9430(03)00335-8
P102. Multidirectional stability of a dynamic stabilization system over graf ligamentoplasty: the effect of various posterior stabilizing implants Osamu Shirado, MD1, Yoshihiro Hojo, MD1, Akio Minami, MD1; 1 Hokkaido University, Sapporo, Japan
P97. Clinical outcome in patients undergoing anterior cervical discectomy and fusion with or without direct uncovertebral joint decompression Francis Shen, MD1, Dino Samartzis1, Edward Goldberg1, Howard An1; 1Rush-Presbyterian-St. Luke’s Medical Center/Rush University, Chicago, IL, USA HYPOTHESIS: Anterior cervical discectomy and fusion (ACDF) is an established procedure for the treatment of cervical disc disease. Studies demonstrate that in patients with radiculopathy secondary to impingement from uncovertebral joint osteophytes, direct decompression of the offending lesion provides excellent clinical outcome. However known complications include vertebral artery injury, dural tears, nerve root injury, and loss of biomechanical stability. Other studies suggest that disc space distraction may also play an important role by indirectly decompressing neural elements. We hypothesis that patients the undergo ACDF without direct uncovertebral joint decompression will have similar clinical outcomes to those that undergo ACDF with direct decompression. METHODS: Clinical outcome of 144 consecutive patients (mean 46 years, range 27–83) that underwent ACDF with constrained plate fixation were reviewed at a single institution. Patients with radiculopathy due to herniated disc, spondylosis, or a combination of both refractory to conservative treatment underwent surgery utilizing a standard Smith-Robinson left-sided approach. Ninety-four patients that received direct uncovertebral joint decompression (group 1) were compared to 50 patients without direct decompression but indirect decompression by disc space distraction (group 2). In group 1, 54 one-level and 40 two-level ACDFs were performed. In group 2, 18 and 32 were one-level and two-level ACDFs respectively. The presence of smoking and work-related injuries involved 32.9% and 43.6% of group 1 and 26% and 32% of group 2, respectively. Autologous iliac crest grafts was used in 65 patients, while 79 patients received allograft. Blinded analyses of plain radiographs were conducted (mean, 9.2 months). Clinical outcomes were reported as excellent, good, fair or poor (mean, 15 months) based on Odom’s criteria. RESULTS: Fusion occurred in 95.7% of group 1 and 100% of group 2. In group 1, 27.7% of the patients reported excellent results, 62.8% reported
doi: 10.1016/S1529-9430(03)00336-X
HYPOTHESIS: An expected advantage of Graf ligamentoplasty over spinal fusion is the decrease risk of adjacent-segment morbidity by stabilizing unstable segments without requiring rigid spinal arthrodesis. However, it remains controversial whether the Graf system can be rigid enough to stabilize an unstable spine. Thus, refinement of the Graf system has recently been highlighted in the literature. The purpose of this study was to biomechanically evaluate multidirectional stability of the dynamic stabilization systems using various posterior stabilizing implants. We hypothesized that this system could provide the multidirectional stability for unstable lumbar spines. METHODS: Twelve fresh calf lumbar spine specimens (L2-sacrum) were subjected to compression (100 N), flexion and extension (5 N-m), lateral bending (5 N-m), and rotation (10 N-m). The load-displacement curves were simultaneously measured. Testing of the intact spine preceded testing of the L4-5 destabilized spine (performed by bilateral medial facetectomies), and in each of the following stabilizing treatment groups: Graf ligamentoplasty, Graf with posterior titanium springs between the pedicle screws, Graf with an interspinous coiled artificial ligament, Graf with an interspinous ceramic spacer, and a rigid pedicle screw system. Extensometers were applied to measure the strain in the stabilized (L4-5) and adjacent segments (L3-4). Statistical analysis was carried out using one-way ANOVA. RESULTS: In the flexion and compression, the strain at L4-5 was not significantly different among all the stabilized constructs except the rigid pedicle screw system. During extension, lateral bending, and rotation, Graf ligamentoplasty enhanced with the various posterior implants were more stable than Graf ligamentoplasty alone (p⬍0.05). The construct enhanced with the ceramic spacer was the most stable of the treatment groups (p⬍.05). The posteriorly enhanced systems were more flexible than the rigid pedicle screw system. Furthermore, the strain at the adjacent segment (L3-4) in the posteriorly enhanced constructs was significantly lower than using the rigid pedicle screw system. DISCUSSION: The current study demonstrates that the Graf ligamentoplasty can provide a multi-directional dynamic stabilization for the