Anterior Cervical Infection: Presentation and Incidence of an Uncommon Postoperative Complication.

STUDY DESIGN: Retrospective multi-institutional case series. OBJECTIVE: The anterior cervical discectomy and fusion (ACDF) affords the surgeon the flexibility to treat a variety of cervical pathologies, with the majority being for degenerative and traumatic indications. Limited data in the literature describe the presentation and true incidence of postoperative surgical site infections. METHODS: A retrospective multicenter case series study was conducted involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network, selected for their excellence in spine care and clinical research infrastructure and experience. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, inclusive, were reviewed to identify the occurrence of 21 predefined treatment complications. Patients who underwent an ACDF were identified in the database and reviewed for the occurrence of postoperative anterior cervical infections. RESULTS: A total of 8887 patients were identified from a retrospective database analysis of 21 centers providing data for postoperative anterior cervical infections (17/21, 81% response rate). A total of 6 postoperative infections after ACDF were identified for a mean rate of 0.07% (range 0% to 0.39%). The mean age of patients identified was 57.5 (SD = 11.6, 66.7% female). The mean body mass index was 22.02. Of the total infections, half were smokers (n = 3). Two patients presented with myelopathy, and 3 patients presented with radiculopathic-type complaints. The mean length of stay was 4.7 days. All patients were treated aggressively with surgery for management of this complication, with improvement in all patients. There were no mortalities. CONCLUSION: The incidence of postoperative infection in ACDF is exceedingly low. The management has historically been urgent irrigation and debridement of the surgical site. However, due to the rarity of this occurrence, guidance for management is limited to retrospective series.

Misplaced Cervical Screws Requiring Reoperation.

STUDY DESIGN: A multicenter, retrospective case series. OBJECTIVE: In the past several years, screw fixation of the cervical spine has become commonplace. For the most part, this is a safe, low-risk procedure. While rare, screw backout or misplaced screws can lead to morbidity and increased costs. We report our experiences with this uncommon complication. METHODS: A multicenter, retrospective case series was undertaken at 23 institutions in the United States. Patients were included who underwent cervical spine surgery from January 1, 2005, to December 31, 2011, and had misplacement of screws requiring reoperation. Institutional review board approval was obtained at all participating institutions, and detailed records were sent to a central data center. RESULTS: A total of 12 903 patients met the inclusion criteria and were analyzed. There were 11 instances of screw backout requiring reoperation, for an incidence of 0.085%. There were 7 posterior procedures. Importantly, there were no changes in the health-related quality-of-life metrics due to this complication. There were no new neurologic deficits; a patient most often presented with pain, and misplacement was diagnosed on plain X-ray or computed tomography scan. The most common location for screw backout was C6 (36%). CONCLUSIONS: This study represents the largest series to tabulate the incidence of misplacement of screws following cervical spine surgery, which led to revision procedures. The data suggest this is a rare event, despite the widespread use of cervical fixation. Patients suffering this complication can require revision, but do not usually suffer neurologic sequelae. These patients have increased cost of care. Meticulous technique and thorough knowledge of the relevant anatomy are the best means of preventing this complication.

A Multicenter Study of the Presentation, Treatment, and Outcomes of Cervical Dural Tears.

STUDY DESIGN: Retrospective multicenter case series study. OBJECTIVE: Because cervical dural tears are rare, most surgeons have limited experience with this complication. A multicenter study was performed to better understand the presentation, treatment, and outcomes following cervical dural tears. METHODS: Multiple surgeons from 23 institutions retrospectively identified 21 rare complications that occurred between 2005 and 2011, including unintentional cervical dural tears. Demographic data and surgical history were obtained. Clinical outcomes following surgery were assessed, and any reoperations were recorded. Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), Nurick classification (NuC), and Short-Form 36 (SF36) scores were recorded at baseline and final follow-up at certain centers. All data were collected, collated, and analyzed by a private research organization. RESULTS: There were 109 cases of cervical dural tears among 18 463 surgeries performed. In 101 cases (93%) there was no clinical sequelae following successful dural tear repair. There were statistical improvements (P < .05) in mJOA and NuC scores, but not NDI or SF36 scores. No specific baseline or operative factors were found to be associated with the occurrence of dural tears. In most cases, no further postoperative treatments of the dural tear were required, while there were 13 patients (12%) that required subsequent treatment of cerebrospinal fluid drainage. Analysis of those requiring further treatments did not identify an optimum treatment strategy for cervical dural tears. CONCLUSIONS: In this multicenter study, we report our findings on the largest reported series (n = 109) of cervical dural tears. In a vast majority of cases, no subsequent interventions were required and no clinical sequelae were observed.

C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases.

STUDY DESIGN: A multicenter, retrospective review of C5 palsy after cervical spine surgery. OBJECTIVE: Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. METHODS: We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ2 tests or Fisher exact tests for categorical variables. RESULTS: Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). CONCLUSION: C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date.

Prevalence and Outcomes in Patients Undergoing Reintubation After Anterior Cervical Spine Surgery: Results From the AOSpine North America Multicenter Study on 8887 Patients.

STUDY DESIGN: A multicenter, retrospective cohort study. OBJECTIVE: To evaluate clinical outcomes in patients with reintubation after anterior cervical spine surgery. METHODS: A total of 8887 patients undergoing anterior cervical spine surgery were enrolled in the AOSpine North America Rare Complications of Cervical Spine Surgery study. Patients with or without complications after surgery were included. Demographic and surgical information were collected for patients with reintubation. Patients were evaluated using a variety of assessment tools, including the modified Japanese Orthopedic Association scale, Nurick score, Neck Disability Index, and Short Form-36 Health Survey. RESULTS: Nine cases of postoperative reintubation were identified. The total prevalence of this complication was 0.10% and ranged from 0% to 0.59% across participating institutions. The time to development of airway symptoms after surgery was within 24 hours in 6 patients and between 5 and 7 days in 3 patients. Although 8 patients recovered, 1 patient died. At final follow-up, patients with reintubation did not exhibit significant and meaningful improvements in pain, functional status, or quality of life. CONCLUSIONS: Although the prevalence of reintubation was very low, this complication was associated with adverse clinical outcomes. Clinicians should identify their high-risk patients and carefully observe them for up to 2 weeks after surgery.

Complications with the use of bone morphogenetic protein 2 (BMP-2) in spine surgery.

BACKGROUND CONTEXT: Recombinant human bone morphogenetic protein 2 (rhBMP-2) is a very potent osteogenic growth factor that has been used successfully in various spine fusions, obviating the need for autologous iliac crest bone graft harvest and therefore avoiding the associated morbidities. PURPOSE: In the past few years, a tremendous increase in rhBMP-2 usage was noted, and concerns regarding costs, benefits, and safety issues were raised by many. The goal of this work was to provide a comprehensive review of the adverse events and complications associated with use of rhBMP-2. STUDY DESIGN: Literature review. METHODS: This is a review of the current literature on the reported adverse events, complications, and concerns associated with rhBMP-2 use. RESULTS: This article discusses the wide spectrum of adverse outcomes related to rhBMP-2 use in the lumbar and the cervical spine; retrograde ejaculation, antibodies formation, postoperative radiculitis, postoperative nerve root injury, ectopic bone formation, vertebral osteolysis/edema, dysphagia and neck swelling, hematoma formation, interbody graft lucency, and wound healing complications are reviewed. Cost-related concerns, dosage considerations, carrier types, and theoretical carcinogenesis concerns were also presented. CONCLUSIONS: Despite the excellent spinal fusion rates promoted by this powerful molecule, the increasingly reported adverse outcomes associated with bone morphogenetic protein usage have created real concerns. This article will provide the reader with a good understanding of the reported complications associated with rhBMP-2 use and ultimately help recognize its safety spectrum and limits for better clinical application.

The molecular basis of intervertebral disc degeneration.

BACKGROUND: Intervertebral disc (IVD) degeneration remains a clinically important condition for which treatment is costly and relatively ineffective. The molecular basis of degenerative disc disease has been an intense focus of research recently, which has greatly increased our understanding of the biology underlying this process. PURPOSE: To review the current understanding of the molecular basis of disc degeneration. STUDY DESIGN: Review article. METHODS: A literature review was performed to identify recent investigations and current knowledge regarding the molecular basis of IVD degeneration. RESULTS: The unique structural requirements and biochemical properties of the disc contribute to its propensity toward degeneration. Mounting evidence suggests that genetic factors account for up to 75% of individual susceptibility to IVD degeneration, far more than the environmental factors such as occupational exposure or smoking that were previously suspected to figure prominently in this process. Decreased extracellular matrix production, increased production of degradative enzymes, and increased expression of inflammatory cytokines contribute to the loss of structural integrity and accelerate IVD degeneration. Neurovascular ingrowth occurs, in part, because of the changing degenerative phenotype. CONCLUSIONS: A detailed understanding of the biology of IVD degeneration is essential to the design of therapeutic solutions to treat degenerative discs. Although significant advances have been made in explaining the biologic mediators of disc degeneration, the inhospitable biochemical environment of the IVD remains a challenging environment for biological therapies.

Aberrant right subclavian artery encountered during debridement of T2 osteomyelitis and associated phlegmon.

BACKGROUND CONTEXT: An aberrant right subclavian artery is a rare congenital abnormality of the aortic arch. The anomalous origin for the right subclavian artery arises as the last branch of the thoracic aorta. In the most common anomalous form, the right subclavian artery passes posterior to both the esophagus and trachea as it crosses midline to supply the right upper extremity. The aberrant right subclavian artery is often not symptomatic, but it can cause dysphagia. PURPOSE: To describe a case of an aberrant right subclavian artery discovered during debridement of T2 osteomyelitis. STUDY DESIGN: Case report. METHODS: A 49-year-old woman with diabetes was transferred to our institution with bilateral lower extremity weakness and incontinence of bowel and bladder function. Examination revealed no motor function in quadriceps, hamstrings, tibialis anterior, extensor hallucis longus, or gastrocsoleus complex of her bilateral lower extremities. RESULTS: Spinal computed tomography scan showed pathologic collapse of the T2 vertebra. Magnetic resonance (MR) demonstrated an abscess and a phlegmon anterior to T2. Magnetic resonance also demonstrated spinal cord compression at the T2 vertebral level, and T2-weighted MR demonstrated the presence of spinal cord signal changes. CONCLUSIONS: We report a rare case where an aberrant right subclavian artery was associated with a T2 osteomyelitis and paravertebral abscess. The intraoperative injury to this aberrant artery led to the eventual death of the patient. When planning an anterior approach to the upper thoracic region, surgeons should be aware of this anatomic variant of the subclavian artery and its associated aberrant recurrent laryngeal nerve.

Multiple unstable cervical fractures with cord compromise treated nonoperatively: a case report.

STUDY DESIGN: The case of a 17-year-old boy who sustained an unusual pattern of multiple unstable cervical spine fractures with a spinal cord injury is presented. OBJECTIVE: To review the management and treatment of multiple unstable cervical spine fractures. SUMMARY OF BACKGROUND DATA.: Combined unstable cervical spine injuries are uncommon. Treatment of multiple-level cervical spine fractures remains controversial. METHODS: The case of a 17-year-old boy who sustained a ring fracture of the atlas, an atypical traumatic spondylolisthesis of the axis, bilateral pedicle fractures of C3 with significant anterior subluxation of C3 on C4, a C6 burst fracture, compression fractures of C7 and T1, and significant cord compression as the result of a motor vehicle accident is presented. RESULTS: The patient was successfully treated with an initial closed reduction using cervical traction for 1 week followed by placement of a cervical halo vest. The fractures healed successfully, and the patient regained near-normal neurologic function. CONCLUSIONS: Despite advances in the surgical treatment of cervical fractures and dislocations, nonoperative treatment with halo immobilization remains a viable option for selected complex injury patterns.

Cervical sprains, disc herniations, minor fractures, and other cervical injuries in the athlete.

In today's health-conscious society, more people are participating in athletic endeavors. As participation increases, so does the incidence of cervical injuries. Fortunately, most of the cervical injuries seen in sports are minor and can be treated successfully with minimal morbidity. It is important, however, to accurately assess the patient sustaining a cervical injury to rule out the presence of a more severe cervical injury. When practitioners understand the pathophysiology and treatment of common injuries, including sprains, strains, contusions, disc herniations, and simple fractures, most athletes can be returned to full function.