Faculty Bibliography

Background/UNASSIGNED:There are multiple complications reported for anterior cervical diskectomy and fusion (ACDF), one of the most common cervical spine operations performed in the US (e.g. estimated at 137,000 ACDF/year). Methods/UNASSIGNED:Multiple studies analyzed the risks and complications rates attributed to ACDF. Results/UNASSIGNED:In multiple studies, overall morbidity rates for ACDF varied from 13.2% to 19.3%. These included in descending order; dysphagia (1.7%-9.5%), postoperative hematoma (0.4%-5.6% (surgery required in 2.4% of 5.6%), with epidural hematoma 0.9%), exacerbation of myelopathy (0.2%-3.3%), symptomatic recurrent laryngeal nerve palsy (0.9%-3.1%), cerebrospinal fluid (CSF) leak (0.5%-1.7%), wound infection (0.1-0.9%-1.6%), increased radiculopathy (1.3%), Horner's syndrome (0.06%-1.1%), respiratory insufficiency (1.1%), esophageal perforation (0.3%-0.9%, with a mortality rate of 0.1%), and instrument failure (0.1%-0.9%). There were just single case reports of an internal jugular veing occlusion and a phrenic nerve injury. Pseudarthrosis occurred in ACDF and was dependant on the number of levels fused; 0-4.3% (1-level), 24% (2-level), 42% (3 level) to 56% (4 levels). The reoperation rate for symptomatic pseudarthrosis was 11.1%. Readmission rates for ACDF ranged from 5.1% (30 days) to 7.7% (90 days postoperatively). Conclusions/UNASSIGNED:Complications attributed to ACDF included; dysphagia, hematoma, worsening myelopathy, recurrent laryngeal nerve palsy, CSF leaks, wound infection, radiculopathy, Horner's Syndrome, respiratory insufficiency, esophageal perforation, and instrument failure. There were just single case reports of an internal jugular vein thrombosis, and a phrenic nerve injury. As anticipated, pseudarthrosis rates increased with the number of ACDF levels, ranging from 0-4.3% for 1 level up to 56% for 4 level fusions.

Background/UNASSIGNED:Although the majority of patients with traumatic/atraumatic osteoporotic vertebral compression fractures (OVCFs) may be managed with non-surgical treatment (NST), a subset (e.g. 40%) with significant pain, loss of vertebral height, and other factors may warrant percutaneous vertebroplasty (V), or percutaneous kyphoplasty (K). Methods/UNASSIGNED:We compared the impact of these three treatment modalities, V, K, or NST, for managing OVCFs. Results/UNASSIGNED:In several studies, both V and K resulted in comparable improvement in pain relief, postoperative kyphotic angles, increased anterior vertebral heights, and frequency of leakage of bone cement. One study evaluating 16 RCT's (Randomized Controlled Studies), however, observed K significantly; "decreased the kyphotic wedge angle, increased the postoperative vertebral body height, and decreased the risk of cement leakage vs. V". Further, in some series, both V and K resulted in higher quality of life scores and better pain relief vs. NST, while other studies showed V was superior to K. Further, although the risk of adjacent level fractures (ALF) following V, K, and NST were comparable in most studies, one clearly demonstrated NST had the lowest incidence of ALF. Despite all these findings, most studies concluded outcomes were comparable for all 3 groups. Conclusions/UNASSIGNED:Although most OVCFs are still managed with non-surgical treatment (NST), a subset (e.g. about 40%) may warrant V or K. Although both V and K have been shown to result in significantly better pain relief, higher quality of life scores, increased postoperative vertebral body height compared with NST, outcomes for all 3 groups remained the same.

Background/UNASSIGNED:Based upon a select review of the literature, in my opinion, spine surgeons, not just our medical/cardiological colleagues, need to know when to stop anticoagulant, anti-platelet aggregates, and non-steroidal anti-inflammatory (NSAIDs) medications prior to spine surgery to avoid perioperative bleeding complications. Methods/UNASSIGNED:Typically, medical/cardiological consultants, who "clear our patients" are not as aware as we are of the increased risks of perioperative bleeding if anticoagulant, anti-platelet, and NSAIDs are not stopped in a timely fashion prior to spine surgery (e.g. excessive intraoperative hemorrhage, and postoperative seromas, hematomas, and wound dehiscence). Results/UNASSIGNED:Different medications need to be discontinued at varying intervals prior to spinal operations. The anticoagulants include; Warfarin (stop at least 5 preoperative days), and Xa inhibitors (Eliquis (Apixaban: stop for 2 days) and Xarelto (Rivaroxaban: stop for 3 days)); note presently data vary. The anti-platelet aggregates include: Aspirin/Clopidogrel (stop >7-10 days preoperatively). The multiple NSAIDs should be stopped for varying intervals ranging from 1-10 days prior to spine surgery, and increase bleeding risks when combined with any of the anticoagulants or anti-platelet aggregates. NSAIDs (generic name/commercial names should be stopped preoperatively for at least; 1 day- Diclofenac (Voltaran), Ibuprofen (Advil, Motrin), Ketorolac (Toradol); 2 days- Etodolac (Lodine), Indomethacin (Indocin); 4-days-Meloxicam (Mobic) and Naproxen (Aleve, Naprosyn, Anaprox); 4 days- Nabumetone (Relafen); 6 days - Oxaprozin (Daypro); and 10 days- Piroxicam (Feldene). Conclusions/UNASSIGNED:Spine surgeons need to know when anti-platelet, anticoagulant, and NSAIDs therapies should be stopped prior to spine surgery to avoid perioperative bleeding complications.

Background/UNASSIGNED:We as spine surgeons increasingly need to carefully screen our own patients for major medical/cardiac comorbidities to determine if they are candidates for spine surgery. Our medical/cardiac colleagues rarely understand how long anti-platelet aggregates and non-steroidal anti-inflammatories (NSAIDs) have to be stopped prior to spine operaeitons, and when it is safe for them to be reinstated. Case Study/UNASSIGNED:A patient over 65 years of age, presented with 6 months of increased bilateral lower extremity sciatica, and 2-block neurogenic claudication. The MR scan showed moderate to severe lumbar stenosis L2-S1 with grade I L4-L5 spondylolisthesis, and multiple bilateral synovial cysts. Nevertheless, his neurological examination was normal. Further, he had > 5 stents placed within the last five years, and had undergone cardiac surgery two years ago requiring placement of a bovine aortic valve, and resection of a left ventricular wall aneurysm. He was also still on full dose Aspirin (325 mg/day), and Clopidogrel (75 mg po bid). Notably, 3 prior spinal surgeons (neurosurgery/orthopedics) had recommended multilevel lumbar laminectomy with instrumented fusions (e.g. including multilevel transforaminal lumbar interbody fusions (TLIF)). Conclusions/UNASSIGNED:Despite multilevel L2-S1 stenosis, Grade I L4-L5 spondylolisthesis, and multilevel bilateral synovial cysts, the patient's normal neurological examination and multiple cardiac comorbidities (i.e. requiring continued full-dose ASA/Clopidogrel) precluded, in my opinion, offering surgical intervention. Rather, I referred the patient to neurology for conservative management. What would you have done?

Background/UNASSIGNED:Extreme lateral interbody fusions (XLIF) and Minimally Invasive (MIS) XLIF pose significant risks of neural injury to the; lumbar plexus, ilioinguinal, iliohypogastric, genitofemoral, lateral femoral cutaneous, and subcostal nerves. To limit these injuries, many intraoperative neural monitoring (IONM) modalities have been proposed. Methods/UNASSIGNED:Multiple studies document various frequencies of neural injuries occurring during MIS XLIF/XLIF: plexus injuries (13.28%); sensory deficits (0-75%; permanent 62.5%); motor deficits (0.7-33.6%; most typically iliopsoas weakness (14.3%-31%)), and anterior thigh/groin pain (12.5-25%.-34%). To avoid/limit these injuries, multiple IONM techniques have been proposed. These include; using finger electrodes during operative dissection, employing motor evoked potentials (MEP), eliminating (no) muscle relaxants (NMR), and using "triggered" EMGs. Results/UNASSIGNED:In one study, finger electrodes for XLIF at L4-L5 level for degenerative spondylolisthesis reduced transient postoperative neurological symptoms from 7 [38%] of 18 cases (e.g. without IONM) to 5 [14%] of 36 cases (with IONM). Two series showed that motor evoked potential monitoring (MEP) for XLIF reduced postoperative motor deficits; they, therefore, recommended their routine use for XLIF. Another study demonstrated that eliminating muscle relaxants during XLIF markedly reduced postoperative neurological deficits/thigh pain by allowing for better continuous EMG monitoring (e.g. NMR no muscle relaxants). Finally, a "triggered" EMG study" reduced postoperative motor neuropraxia, largely by limiting retraction time. Conclusion/UNASSIGNED:Multiple studies have offered different IONM techniques to avert neurological injuries following MIS XLIF/XLIF. Does this mean that these procedures (e.g. XLIF/MIS XLIF) are unsafe?

Background/UNASSIGNED:Extreme lateral interbody fusions (XLIF) and Minimally Invasive (MIS) XLIF were developed to limit the vascular injuries associated with anterior lumbar interbody fusion (ALIF), and minimize the muscular/ soft tissue trauma attributed to transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterolateral lumbar fusion (PLF). Methods/UNASSIGNED:Nevertheless, XLIF/MIS XLIF pose significant additional risks and complications that include; multiple nerve injuries (e.g. lumbar plexus, ilioinguinal, iliohypogastric, genitofemoral, lateral femoral cutaneous, and subcostals (to the anterior abdominal muscles: abdominal oblique), and sympathectomy), major vascular injuries, bowel perforations/postoperative ileus, seromas, pseudarthrosis, subsidence, and reoperations. Results/UNASSIGNED:The risks of neural injury with XLIF/MIS XLIF (up to 30-40%) are substantially higher than for TLIF, PLIF, PLF, and ALIF. These neural injuries included: lumbar plexus injuries (13.28%); new sensory deficits (0-75% (21.7%-40%); permanent 62.5%); motor deficits (0.7-33.6%-40%); iliopsoas weakness (9%-31%: permanent 5%), anterior thigh/groin pain (12.5-34%), and sympathectomy (4%-12%). Additional non-neurological complications included; subsidence (10.3%-13.8%), major vascular injuries (0.4%), bowel perforations, recurrent seroma, malpositioning of the XLIF cages, a 45% risk of cage-overhang, pseudarthrosis (7.5%), and failure to adequately decompress stenosis. In one study, reviewing 20 publications and involving 1080 XLIF patients, the authors observed "Most (XLIF) studies are limited by study design, sample size, and potential conflicts of interest." Conclusion/UNASSIGNED:Many new neurological deficits and other adverse events/complications are attributed to MIS XLIF/ XLIF. Shouldn't these significant risk factors be carefully taken into consideration before choosing to perform MIS XLIF/XLIF?