Guru Reddy

Significantly improved lumbar arthroplasty placement using image guidance: technical note.

Study Design. Technical report. Objective. To compare the accuracy of lumbar total disc arthroplasty placement using an image-guidance system (IGS) with conventional fluoroscopy. Summary of Background Data. Most disc arthroplasties are inserted and analyzed using fluoroscopy. One previous cadaveric study demonstrated beneficial, but insignificant, effects of IGS on total disc arthroplasty placement compared with conventional fluoroscopy. Methods. Patients were considered for lumbar total disc arthroplasty who had chronic discogenic low back pain unresponsive to nonoperative management for at least 6 months. Total disc arthroplasty was performed in n = 6 with IGS and in n = 14 without IGS. Implant placement was analyzed after surgery using computer software on high-resolution CT with respect to 3 parameters: 1) off-center mal-placement, 2) axial rotational mal-placement, and 3) coronal tilt. Results. Arthroplasties inserted with IGS were positioned with significantly greater accuracy than non-IGS arthroplasties with respect to all 3 parameters measured (off-center: 1.1 ± 0.3 vs. 2.3 ± 0.3 mm, P = 0.031; rotation: 88.8° ± 0.2° vs. 87.1° ± 0.4°; P = 0.0084; and tilt: 1.0° ± 0.5° vs. 2.6° ± 0.3°, P = 0.01). There was no significant difference in operating time between non-IGS controls (123 ± 5 minutes) and IGS (139 ± 10 minutes) groups (P = 0.129). Conclusion. This is the first clinical study to demonstrate significantly improved accuracy of lumbar total disc arthroplasty placement on CT using IGS compared with conventional fluoroscopy. IGS should be considered for routine use with lumbar total disc arthroplasty insertion.

Long-term results of multilevel (three and four levels) cervical disc arthroplasty: age-weighted linear regression analysis—results from a single centre

IntroductionThe clinical outcomes of Multi-level disc arthroplasties are variable in the literature. However, the outcome results related to age would have a significant bearing on our decisions in...

Outcomes of Decompression and Stabilization with a Pedicle-Based Semirigid Posterior Stabilization System in the Lumbar Spine

Introduction Patients with lumbar spinal stenosis who do not respond satisfactorily to nonoperative measures may require decompression. Laminectomies/decompression without instrumentation may cause instability and associated symptoms. Fusion often involves multiple segments potentially increasing the risk of proximal junctional kyphosis (PJK), adjacent segment disease (ASD), and surgical morbidity of lateral exposure to prepare fusion bed. We have therefore been using the TRANSITION Stabilization System (Globus Medical, Inc., Audubon, Pennsylvania, United States) to provide stability without fusion at the operated levels. Following insertion of pedicle screws, to which the rod is attached, a semirigid rod is custom built along a central cord using a combination of rigid screw head attachments, flexible spacers, and a compressible bumper. Biomechanical studies have indicated superior performance to other similar systems. We report our clinical results. Patients and Methods A retrospective analysis of prospectively collected data was performed for patients who underwent surgery between September 2011 and December 2013. Outcome measures included Oswestry Disability Index (ODI), Visual Analog Scale (VAS) back/leg pain, Hospital Anxiety and Depression Scale, and complications. Statistical analysis was performed with paired and unpaired tests. Results Demographics: Data were available for 24 patients; 8 females and 16 males. Mean age at surgery was 66.8 years. Mean body mass index was 30.4 kg/m2. Mean length of follow-up was 44 (range, 10–109) weeks. Mean postoperative length of stay was 7.2 days, and when those patients requiring reoperation for complications were excluded it was 4.4 days. Surgery: A total of 10 L3–S1, 4 L4–S1, 1 L4–L5, 3 L2–L5, 4 L3–L5, 1 L1–L5, and 1 L2–S1 stabilizations were performed with a variety of combined central and foraminal decompressions. Mean blood loss was 648 mL and surgical time 176 minutes. Eight patients sustained intraoperative dural tears that were sealed with fibrin sealant. Outcomes: Mean ODI improved from 45.1 to 31.3 (p = 0.001), VAS back from 6.7 to 3.7 (p ≤ 0.01), VAS legs from 6.7 to 2 (p ≤ 0.01), anxiety from 6.1 to 5.4 (p = 0.37), and depression from 7.3 to 3.7 (p = 0.033). There was no statistical correlation between pre- and postoperative ODI, VAS back or legs, depression/anxiety scores, and demographics. Reoperations: There were three early reoperations: one patient for discharging wound with positive microbiology and for revision of a screw, one patient for discharging wound with negative microbiology, and one patient for revision of a screw. There were no implant failures or revisions for PJK or ASD to date. Conclusion Our results using the TRANSITION Stabilization System suggests that pedicle-based semirigid posterior stabilization systems warrant further consideration as a potential tool in providing satisfactory early postoperative results while potentially reducing the long-term morbidity associated with fusions for lumbar stenosis. We would encourage further research to assess longer term results and radiographic outcomes.