The Spine Journal 15 (2015) 433–434
Commentary
Anterior cervical discectomy and fusion surgery for cervical radiculopathy: is time of essence? John M. Rhee, MD* Department of Orthopaedic Surgery, Emory Spine Center, Emory University School of Medicine Atlanta, GA, USA Received 31 October 2014; accepted 8 November 2014
COMMENTARY ON: Burneikiene S, Nelson EL, Mason A, Rajpal S, Villavicencio AT. The duration of symptoms and clinical outcomes in patients undergoing anterior cervical discectomy and fusion for degenerative disc disease and radiculopathy. Spine J 2015;15:427–32 (in this issue).
Anterior cervical discectomy and fusion (ACDF) is popularly regarded as one of the most successful surgeries performed on the spine. It demonstrates not only a high success rate in improving preoperative symptoms, but also has a very favorable safety/complication profile. In addition, patients tend to tolerate the procedure well, with relatively little postoperative pain and morbidity when compared with some other commonly performed spinal operations. However, because the natural history of cervical radiculopathy is favorable in the vast majority of cases, surgery is rightly reserved for those who fail to improve over time. In an ideal world, it would be possible to predict at the onset of symptoms those who will eventually require surgery versus those likely to improve without surgery. Being able to sort this out at the onset would allow patients to get the treatment they need in a timely fashion, limit the amount of time spent in pain and suffering, and may even have economic benefits in terms of earlier return to function and less health care resources used on treatments that ultimately prove ineffective. Although a variety of baseline factors have been evaluated, none have proven to be a prognostic holy grail, and thus, it remains impossible at present to predict who will require surgery.
FDA device/drug status: Not applicable. Author disclosures: JMR: Roylaties: Biomet Spine (D); Stock Ownership: Phygen/Alphatec (!1% stock ownership); Consulting: Biomet Spine (B); Speaking and/or Teaching Arrangements: Zimmer Spine (C), Depuy Spine (B); Board of Directors: CSRS. The disclosure key can be found on the Table of Contents and at www. TheSpineJournalOnline.com. * Corresponding author. Department of Orthopaedic Surgery, Emory Spine Center, Emory University School of Medicine, 59 Executive Park South, Atlanta, GA 30329, USA. E-mail address: [email protected] (J.M. Rhee) http://dx.doi.org/10.1016/j.spinee.2014.11.005 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
In this issue of The Spine Journal, the authors ask another important question: given that we cannot predict from the outset who will need surgery, is it at least possible that earlier surgery for cervical radiculopathy may result in better outcomes? [1] To examine this question, they performed a post hoc analysis of a cohort of patients from a previous study [2] by the same authors. In the previous study, the authors evaluated the effect of lordotic versus parallel ACDF grafts on outcomes in 122 patients with cervical radiculopathy and myelopathy, who were randomized to ACDF with either one of the two graft configurations. In that study, the authors found no differences between the two groups and concluded that ‘‘the use of lordotically shaped allografts does not increase cervical/segmental sagittal alignment or improve clinical outcomes.’’ For the present study, the authors selected 58 of those 122 original patients based on the presence of degenerative cervical radiculopathy for which they underwent one- or two-level ACDF. Average follow-up time was 37.2 months (range 12–54 months). These patients were then separated into those who had surgery within 6 months of onset of symptoms (n529) versus those who had surgery more than 6 months after becoming symptomatic (n529). Postoperatively, both groups had significant improvements in visual analog scale (VAS)-neck pain and Neck Disability Index scores compared with preoperative. However, only the #6 months group had significantly better VAS-arm pain and Short Form 36-physical component scores postoperatively. Although the O6 months group demonstrated improvements in VAS-arm pain and Short Form 36-physical component scores, these improvements did not reach statistical significance compared with preoperative. Accordingly, the #6 months group had significantly better reduction in arm pain than the O6 months
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J.M. Rhee / The Spine Journal 15 (2015) 433–434
group. Despite this difference, however, there were no differences in measures of postoperative satisfaction with surgical outcome or improvement in neurologic symptoms between the two groups. The authors concluded that ‘‘patients with shorter duration of symptoms have better improvement in radiculopathy symptoms that is statistically significant.’’ There are a number of potential explanations for this finding. First, the authors suggest that operating before 6 months may improve outcomes by relieving root compression before the onset of ‘‘irreversible nerve damage.’’ Although this explanation is certainly possible, the study is not designed to provide direct evidence of such a mechanism. However, another real possibility is potential selection bias. Patients were randomized to the type of graft (lordotic vs. parallel), but not randomized to early versus later surgery. Thus, there could be two distinct populations of patients and pathologies in the two groups. In fact, although the two groups were separated by the 6-month cutoff point that divided the overall population into two equal groups (n529 each), the median time to surgery in the two groups was vastly different—1.8 months versus 24 months. Perhaps, the early group underwent early surgery because their symptoms were more ‘‘acute’’? The physiology of radiculopathy can vary widely depending on the structural cause of the radiculopathy—soft disc versus spondylosis. Additionally, the chronic (vs. acute) radiculopathy patient may often present with a different sort of ‘‘arm pain’’: manifested primarily around the scapula and trapezial region, which may radiate down the arm but be less ‘‘dermatomal’’ in nature. In that scenario, making the correct diagnosis of causative levels is more difficult, and thus, the outcomes may suffer accordingly if the proper pain generator is not identified. For example, diagnosing an acute ‘‘classic’’ C6 radiculopathy with radiating pain into the thumb associated with a large C5–C6 herniated disc on magnetic resonance imaging is reasonably straightforward. On the other hand, identifying the pain generator(s) in a patient with periscapular pain and nondermatomal radiation into the arm is more difficult, particularly if the patient does not have an obvious disc herniation but rather presents with multiple areas of spondylotic foraminal narrowing, any one or more of which could be causative.
Regardless of the explanation, the findings of the study are instructive but obviously should not be interpreted to suggest that ‘‘early’’ surgery is best in all radiculopathy patients. As noted previously, cervical radiculopathy has a generally favorable outcome for resolution. The authors very appropriately recognize this fact and state their conclusions accordingly. There are some important take home points to consider. First, surgery should be reserved for those with refractory radiculopathy. Second, in those who are surgical candidates and who opt for surgery anyway, it would seem reasonable to go ahead and get it done rather than delay or continue with other treatments that are not working. Third, the definition of ‘‘early’’ remains debatable, but one possible definition based on this study could be within 6 months of symptom onset. Future work might narrow down the window—8 weeks? 3 months? Fourth, is there a difference based on a diagnosis of soft disc herniation versus spondylotic radiculopathy, since the two share much in common but likely have somewhat different underlying pathophysiology? What we can discern from this study is that, for the population studied in this article (a mixed collection of patients with disc herniation and spondylotic radiculopathy), surgery within 6 months of symptom onset was associated with better arm pain relief. This finding is in line with studies quoted by the authors with respect to leg pain and timing of surgery for lumbar radiculopathy. What cannot be discerned from the data presented is why. Nevertheless, this study does appear to add to a growing body of literature that when treating neurologic compression surgically, time may be of at least some essence.
References [1] Burneikiene S, Nelson EL, Mason A, Rajpal S, Villavicencio AT. The duration of symptoms and clinical outcomes in patients undergoing anterior cervical discectomy and fusion for degenerative disc disease and radiculopathy. Spine J 2015;15:427–32. [2] Villavicencio AT, Babuska JM, Ashton A, Busch E, Roeca C, Nelson EL, et al. Prospective, randomized, double blind clinical study evaluating the correlation of clinical outcomes and cervical sagittal alignment. Neurosurgery 2011;68:1309–16; discussion 1316.
Commentary
Anterior cervical discectomy and fusion surgery for cervical radiculopathy: is time of essence? John M. Rhee, MD* Department of Orthopaedic Surgery, Emory Spine Center, Emory University School of Medicine Atlanta, GA, USA Received 31 October 2014; accepted 8 November 2014
COMMENTARY ON: Burneikiene S, Nelson EL, Mason A, Rajpal S, Villavicencio AT. The duration of symptoms and clinical outcomes in patients undergoing anterior cervical discectomy and fusion for degenerative disc disease and radiculopathy. Spine J 2015;15:427–32 (in this issue).
Anterior cervical discectomy and fusion (ACDF) is popularly regarded as one of the most successful surgeries performed on the spine. It demonstrates not only a high success rate in improving preoperative symptoms, but also has a very favorable safety/complication profile. In addition, patients tend to tolerate the procedure well, with relatively little postoperative pain and morbidity when compared with some other commonly performed spinal operations. However, because the natural history of cervical radiculopathy is favorable in the vast majority of cases, surgery is rightly reserved for those who fail to improve over time. In an ideal world, it would be possible to predict at the onset of symptoms those who will eventually require surgery versus those likely to improve without surgery. Being able to sort this out at the onset would allow patients to get the treatment they need in a timely fashion, limit the amount of time spent in pain and suffering, and may even have economic benefits in terms of earlier return to function and less health care resources used on treatments that ultimately prove ineffective. Although a variety of baseline factors have been evaluated, none have proven to be a prognostic holy grail, and thus, it remains impossible at present to predict who will require surgery.
FDA device/drug status: Not applicable. Author disclosures: JMR: Roylaties: Biomet Spine (D); Stock Ownership: Phygen/Alphatec (!1% stock ownership); Consulting: Biomet Spine (B); Speaking and/or Teaching Arrangements: Zimmer Spine (C), Depuy Spine (B); Board of Directors: CSRS. The disclosure key can be found on the Table of Contents and at www. TheSpineJournalOnline.com. * Corresponding author. Department of Orthopaedic Surgery, Emory Spine Center, Emory University School of Medicine, 59 Executive Park South, Atlanta, GA 30329, USA. E-mail address: [email protected] (J.M. Rhee) http://dx.doi.org/10.1016/j.spinee.2014.11.005 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
In this issue of The Spine Journal, the authors ask another important question: given that we cannot predict from the outset who will need surgery, is it at least possible that earlier surgery for cervical radiculopathy may result in better outcomes? [1] To examine this question, they performed a post hoc analysis of a cohort of patients from a previous study [2] by the same authors. In the previous study, the authors evaluated the effect of lordotic versus parallel ACDF grafts on outcomes in 122 patients with cervical radiculopathy and myelopathy, who were randomized to ACDF with either one of the two graft configurations. In that study, the authors found no differences between the two groups and concluded that ‘‘the use of lordotically shaped allografts does not increase cervical/segmental sagittal alignment or improve clinical outcomes.’’ For the present study, the authors selected 58 of those 122 original patients based on the presence of degenerative cervical radiculopathy for which they underwent one- or two-level ACDF. Average follow-up time was 37.2 months (range 12–54 months). These patients were then separated into those who had surgery within 6 months of onset of symptoms (n529) versus those who had surgery more than 6 months after becoming symptomatic (n529). Postoperatively, both groups had significant improvements in visual analog scale (VAS)-neck pain and Neck Disability Index scores compared with preoperative. However, only the #6 months group had significantly better VAS-arm pain and Short Form 36-physical component scores postoperatively. Although the O6 months group demonstrated improvements in VAS-arm pain and Short Form 36-physical component scores, these improvements did not reach statistical significance compared with preoperative. Accordingly, the #6 months group had significantly better reduction in arm pain than the O6 months
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J.M. Rhee / The Spine Journal 15 (2015) 433–434
group. Despite this difference, however, there were no differences in measures of postoperative satisfaction with surgical outcome or improvement in neurologic symptoms between the two groups. The authors concluded that ‘‘patients with shorter duration of symptoms have better improvement in radiculopathy symptoms that is statistically significant.’’ There are a number of potential explanations for this finding. First, the authors suggest that operating before 6 months may improve outcomes by relieving root compression before the onset of ‘‘irreversible nerve damage.’’ Although this explanation is certainly possible, the study is not designed to provide direct evidence of such a mechanism. However, another real possibility is potential selection bias. Patients were randomized to the type of graft (lordotic vs. parallel), but not randomized to early versus later surgery. Thus, there could be two distinct populations of patients and pathologies in the two groups. In fact, although the two groups were separated by the 6-month cutoff point that divided the overall population into two equal groups (n529 each), the median time to surgery in the two groups was vastly different—1.8 months versus 24 months. Perhaps, the early group underwent early surgery because their symptoms were more ‘‘acute’’? The physiology of radiculopathy can vary widely depending on the structural cause of the radiculopathy—soft disc versus spondylosis. Additionally, the chronic (vs. acute) radiculopathy patient may often present with a different sort of ‘‘arm pain’’: manifested primarily around the scapula and trapezial region, which may radiate down the arm but be less ‘‘dermatomal’’ in nature. In that scenario, making the correct diagnosis of causative levels is more difficult, and thus, the outcomes may suffer accordingly if the proper pain generator is not identified. For example, diagnosing an acute ‘‘classic’’ C6 radiculopathy with radiating pain into the thumb associated with a large C5–C6 herniated disc on magnetic resonance imaging is reasonably straightforward. On the other hand, identifying the pain generator(s) in a patient with periscapular pain and nondermatomal radiation into the arm is more difficult, particularly if the patient does not have an obvious disc herniation but rather presents with multiple areas of spondylotic foraminal narrowing, any one or more of which could be causative.
Regardless of the explanation, the findings of the study are instructive but obviously should not be interpreted to suggest that ‘‘early’’ surgery is best in all radiculopathy patients. As noted previously, cervical radiculopathy has a generally favorable outcome for resolution. The authors very appropriately recognize this fact and state their conclusions accordingly. There are some important take home points to consider. First, surgery should be reserved for those with refractory radiculopathy. Second, in those who are surgical candidates and who opt for surgery anyway, it would seem reasonable to go ahead and get it done rather than delay or continue with other treatments that are not working. Third, the definition of ‘‘early’’ remains debatable, but one possible definition based on this study could be within 6 months of symptom onset. Future work might narrow down the window—8 weeks? 3 months? Fourth, is there a difference based on a diagnosis of soft disc herniation versus spondylotic radiculopathy, since the two share much in common but likely have somewhat different underlying pathophysiology? What we can discern from this study is that, for the population studied in this article (a mixed collection of patients with disc herniation and spondylotic radiculopathy), surgery within 6 months of symptom onset was associated with better arm pain relief. This finding is in line with studies quoted by the authors with respect to leg pain and timing of surgery for lumbar radiculopathy. What cannot be discerned from the data presented is why. Nevertheless, this study does appear to add to a growing body of literature that when treating neurologic compression surgically, time may be of at least some essence.
References [1] Burneikiene S, Nelson EL, Mason A, Rajpal S, Villavicencio AT. The duration of symptoms and clinical outcomes in patients undergoing anterior cervical discectomy and fusion for degenerative disc disease and radiculopathy. Spine J 2015;15:427–32. [2] Villavicencio AT, Babuska JM, Ashton A, Busch E, Roeca C, Nelson EL, et al. Prospective, randomized, double blind clinical study evaluating the correlation of clinical outcomes and cervical sagittal alignment. Neurosurgery 2011;68:1309–16; discussion 1316.
