Abstract and Introduction
Abstract
Introduction: The relationship between surgeon experience and cervical fusion outcomes has yet to be assessed. We investigate perioperative characteristics, patient-reported outcomes (PROMs), and minimal clinically important difference (MCID) achievement after anterior cervical diskectomy and fusion (ACDF) by the volume of cases done throughout an orthopaedic spine surgeon's career.
Methods: ACDF procedures between 2005 and 2020 were identified. Group I included the first half of ACDF cases (#1-#321). PROMs were introduced in the second half of the ACDF cases; thus, the next 322 cases were subdivided to compare PROM and MCID between subgroups (cases #322 to #483 = group II and #484 to #645 = group III). PROMs, including VAS back/leg, Oswestry Disability Index (ODI), Short Form-12 Physical Composite Score, and PROMIS-PF, were collected preoperatively/postoperatively. Demographics, perioperative variables, mean PROMs, and MCID achievement were compared between groups and subgroups using the Student t-test and chi-square. Logistic regression evaluated MCID achievement using the established threshold values.
Results: A total of 642 patients were included (320 in group I, 161 in group II, and 161 in group III). The latter cases had significantly decreased surgical time, blood loss, and postoperative length of stay in comparison of groups and subgroups (P ≤ 0.002, all). CT-confirmed 1-year arthrodesis rates were increased among the latter cases (P = 0.045). Group II had significantly higher arthrodesis rates than group III (P = 0.039). The postoperative complication rates were lower in the latter cases (P < 0.001, all), whereas subgroup analysis revealed lower incidence of urinary retention and other complications in group III (P ≤ 0.031, all). Mean PROMs were significantly inferior in group II versus group III for VAS neck at 6 months (P = 0.030), Neck Disability Index at 6 months preoperatively (P ≤ 0.022, both), Short Form-12 Physical Composite Score at 12 weeks/2 years (P ≤ 0.047, both), and PROMIS-PF at 12 weeks/6 months (P ≤ 0.036, both). The MCID attainment rates were higher among group III for VAS neck/Neck Disability Index at 2 years (P ≤ 0.005) and overall achievement across all PROMs (P ≤ 0.015, all).
Discussion: Increased ACDF case volume may lead to markedly decreased surgical time, blood loss, and length of postoperative stay as well as improved clinical outcomes in pain, disability, and physical function.
Introduction
Since first described in 1958 by Robinson and Smith,[1] anterior cervical diskectomy and fusion (ACDF) has become one of the most common spinal procedures for degenerative cervical spine diseases, cited for minimal risk and reliability.[2] In the United States alone, cervical fusion procedures have risen by 206% from 1992 to 2005 among elderly Medicare patients.[3] Between 2006 and 2013, an average of 137,000 ACDFs were done yearly.[4]
An ACDF procedure allows for direct decompression of the spinal cord and neural foramen.[5] To do so, surgeons may approach the patients' cervical spine anteriorly with a right-side skin incision as described by Robinson and Smith.[1] Once the disk is identified and removed, decompression of the spinal cord and nerve roots up to the uncovertebral joints is achieved and a fusion is done by using either autologous bone graft or allograft cervical spacer with the demineralized bone matrix.[6] In many cases, anterior cervical plating is used to prevent graft collapse.[6]
High success rates of the procedure have led to an increasing interest in rapid mobilization protocols after ACDF, and recent years have seen an increasing movement of ACDF cases toward same-day surgery and ambulatory surgery center environments.[6–8] In fact, because healthcare costs have increased in the United States, with 7% of the gross domestic product spent on surgical care, outpatient ambulatory surgery centers are able to decrease costs by nearly 30% compared with inpatient care.[3] With additional advances in anesthesiology, surgical techniques, and perioperative care, many inpatient surgeries, such as ACDF, have the means to transition to the outpatient setting.[9] Likely due to such advancements, average postoperative length of stay (LOS) for ACDF patients has been drastically reduced, with over 80% of patients being discharged within less than 2 days and several studies reporting LOS 24 hours or less after fusion.[9–11]
Despite many studies demonstrating the efficacy of ACDF as treatment for degenerative cervical spine disease with outstanding long-term clinical outcomes,[6,12] the morbidities associated with the anterior cervical approach range from 13.2% to 19.3%.[12,13] Although some morbidities, such as dysphonia or dysphagia, are often self-limiting and relatively benign, the ACDF procedure along with the complex regional anatomy of the anterior neck can lead to life-threatening complications, such as hematoma and esophageal injury.[12–14] Therefore, it is critical to identify the means of reducing complication rates while aiming to optimize patient outcomes.
With outpatient ACDF procedures deemed favorable for well-selected patients,[10] it is important to understand the increased risk of the procedure and identify ways to reduce complication rates while making note of the time surgeons are to become proficient during their careers. A previous study reporting on the learning curve after ACDF suggested proficiency to occur by case number 60 in a surgeon's career.[14] This study sought to build on this previous work to assess the longitudinal relationship of surgeon experience, with the volume of cases done as the independent variable, on perioperative outcomes, complications, and postoperative patient-reported outcome measures (PROMs), and minimal clinically important difference (MCID) attainment within the ACDF cohort. This objective was evaluated by comparing early and late case outcomes of a single orthopaedic spine surgeon with over a decade of experience at a single academic institution.
J Am Acad Orthop Surg. 2022;30(5):e537-e546. © 2022 American Academy of Orthopaedic Surgeons
