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Friday, May 20, 2016

Advanced age is associated with an increased comorbidity burden and higher rate of complications following surgery of any kind. As the population ages, there will be an increasing number of patients over age 80 with degenerative lumbar conditions. While many of these patients may have had lower functional expectations in the past, this age group is now expecting to remain active and has a greater enthusiasm for spinal surgery than previous generations of elderly patients. Lumbar fusion is a relatively invasive procedure with a significant rate of complications, and many surgeons are reluctant to perform fusion on elderly patients due to concerns about medical complications, wound healing problems, hardware failure, and overall worse results. In order to address this question, Dr. Marbacher and colleagues from Zurich reviewed over 700 patients over age 50 treated with one to three level lumbar fusion, with or without decompression. They identified 317 patients age 50-65 ("younger" group), 350 patients age 65-80 ("older" group), and 40 patients over 80 ("elderly" group) who met their inclusion criteria. They evaluated patient reported outcomes (i.e. Core Outcome Measures Index [COMI], global result, and patient satisfaction) out to 2 years as well as medical and surgical complications recorded during their surgical admission. The patient reported outcomes were not significantly different among the three age strata with the exception of global outcome at 3 months, which was significantly worse for the elderly group (72% "good" outcome in the elderly vs. 85% in the younger group). Medical complications were significantly higher in the elderly group (17.5% elderly vs. 7.5% younger), with cardiovascular (7.5%), cerebral (5%), and kidney/urinary (10%) complications the most common complications in the elderly cohort. Surgical complications were somewhat more common in the elderly, with dural tear being more common among the elderly (10% elderly vs. 3.5% younger). The length of stay was also somewhat longer for the elderly (11.3 days elderly vs. 10 days younger), with these lengths of stay being much longer than those observed in the United States. Based on these data, the authors concluded that elderly patients had similar patient reported outcomes but higher complication rates compared to younger patients undergoing lumbar fusion.

This paper is an important contribution to the literature as there is very little data on outcomes following lumbar fusion in octogenarians, and this population is presenting to spine surgeons in greater numbers. Spine surgeons frequently do not know how to treat these patients as they are caught in a conflict between wanting to help improve these patients' quality of life yet also wanting to avoid complications. While it comes as no surprise that elderly patients have higher rates of complications, it is reassuring that they have similar patient reported outcomes. Other studies have demonstrated that short term complications generally do not affect longer term patient reported outcomes, and this paper seems to reflect that. The worse global outcomes at three months for the elderly patients likely reflects a longer recovery time and may be capturing some of the short term morbidity associated with complications. This paper suggests that good results can be obtained with lumbar fusion in the elderly population, however, one must consider that only 40 of over 700 patients were over 80, and they likely represent a highly selected group. Despite this, they still had a significantly higher rate of complications. Additionally, the authors focused on in-hospital complications during the surgical admission, and complications occurring after discharge including wound healing problems, infection, and hardware complications may not have been captured. They reported an overall infection rate of under 1% (0% in the elderly group), which is remarkably low for lumbar fusion, suggesting that some wound complications may not have been captured. Despite the limitations inherent in this observational study design, the results indicate that age alone should not be a contra-indication to lumbar fusion. Properly selected octogenarians can do well with fusion surgery, though they need to be informed about their increased risk of complications during the informed consent process.

Please read Dr. Marbacher's paper on this topic in the May 15 issue. Does this change how you consider lumbar fusion for elderly patients? Let us know by leaving a comment on The Spine Blog.

Adam Pearson, MD, MS

Associate Web Editor


Friday, May 13, 2016

Degenerative lumbar scoliosis (DLS) is a heterogeneous condition that has been difficult to classify, study, and treat in a systematic fashion. Given the heterogeneity in symptom severity, radiographic findings, and patient characteristics, clear-cut treatment guidelines have been elusive, and there is likely marked variation in how it is treated. Depending on whom they see, the same patient could be treated with physical therapy, a small decompression surgery, or a deformity correction with osteotomies and thoracolumbopelvic fixation. In areas such as this where high quality evidence is lacking and would be difficult to produce, experts have attempted to create appropriateness criteria to guide care. The RAND/UCLA method is the most widely-accepted approach to this, and it involves a thorough literature review, creation of different clinical scenarios, and a modified Delphi process to gain consensus among a panel of experts about appropriate and inappropriate treatment for each scenario. Dr. Chen and her colleagues in the DLS Appropriateness Group went through such a process and published their results in the May 1 issue. They created 260 scenarios based on stenosis severity, curve magnitude, sagittal imbalance, curve progression, and medical comorbidities. They then assessed the appropriateness of different surgical treatment, namely combinations of decompression, fusion, and deformity correction. Not surprisingly, surgery was viewed as less appropriate for patients with mild symptoms, mild stenosis, and mild deformity and for patients with severe comorbidities. Decompression alone was considered appropriate for cases of stenosis with low magnitude curves without imbalance or progression. Fusion and deformity correction were considered appropriate for cases with greater curve magnitude, imbalance, and/or progression.

 

The authors should be applauded for attempting to systematize treatment of a condition that has defied classification over the years. Their findings tend to support the conventional wisdom of spine surgeons, which is not surprising since that is what they used to create the criteria. Given the lack of high quality studies on this topic—due in part to the lack of a good classification system—expert opinion is all we have to go on. In order to validate these criteria, a huge clinical study would need to be performed in order to determine if patients treated "appropriately" did better than those treated "inappropriately". While the authors have done a nice job distilling the salient factors in DLS, a greater level of detail is needed for surgeons to guide their decision-making. Where should the fusion start and end? How much sagittal imbalance is acceptable? Is an osteotomy necessary? Should the deformity be corrected or fused in situ? How should medical comorbidity affect my selection of an operation? It seems unlikely that clinical studies or practice guidelines will ever be able to reach the level of granularity needed to be clinically useful for this complex condition. Surgeons will need to continue to depend on their judgment and experience when answering these questions. When we get to the point that algorithms can determine the best surgical treatment for DLS, traditional spine surgeons can be replaced by technicians who simply carry out the surgical plan dictated by the algorithm. It seems unlikely that we'll see such progress for DLS anytime soon. Until then, guidelines like this can help organize one's thinking, but the treatment of DLS will remain more art than science.

 

Please read Dr. Chen's article on this topic in the May 1 issue. Does this change how you view the treatment of DLS? Let us know by leaving a comment on The Spine Blog.

Adam Pearson, MD, MS

Associate Web Editor


Saturday, May 7, 2016

Reoperation following surgical treatment of lumbar spinal stenosis (SpS) is a relatively common event. Acute surgical complications such as infection, hardware malposition, and spinal fluid leak can all necessitate reoperation in the short term. Medium and longer term problems such as progressive spondylolisthesis or recurrent stenosis at the index or adjacent levels can also lead to reoperation. Revision surgery is technically more challenging than primary surgery, leading to higher rates of complications, higher costs, and worse outcomes than primary surgery. As such, it is important to understand risk factors for reoperation so that any modifiable factors can be addressed preoperatively and so that patients can be counseled about their risk of reoperation based on their individual characteristics. In order to better understand risk factors for reoperation, Dr. Gerling and colleaugues used the Spine Patient Outcomes Research Trial (SPORT) SpS data to compare baseline characteristics between patients who underwent reoperation and those who did not. The study included over 400 patients who underwent surgical treatment for SpS, who were then followed for up to 8 years. Eighty-eight percent of patients underwent laminectomy alone, while 12% also underwent a posterolateral fusion. Over the eight years of follow-up, 18% of patients underwent reoperation, and 42% of reoperations were performed within 2 years of the index surgery.  Progressive spondylolisthesis or recurrent stenosis at the index or adjacent level was the most common indication for reoperation (52% of reoperations). Acute complications (i.e. wound infection) were the next most common cause of reoperation (15% of reoperations). Despite evaluating over fifty different patient and disease characteristics, the only significant baseline difference between the reoperation and no reoperation groups was that the reoperation group had a somewhat lower rate of neurological deficit preoperatively. Given the high number of statistical comparisons and lack of any adjustment of the threshold for statistical significance (i.e. Bonferroni correction), it is expected that 1 or 2 variables would come up as "significant". As such, it is hard to know if this association is meaningful. Not suprisingly, the clinical outcomes were worse in the reoperation group. While the fusion group was quite small, there were no significant differences in clinical outcomes or reoperation rates between the fusion and no fusion groups.

 

This is an important paper that probably represents the largest series of prospectively followed patients undergoing reoperation following SpS surgery (77 reoperations). While the authors refer to the "overall low reoperation rate", some might find an 18% rate relatively high. This is a relatively high rate compared to other elective orthopaedic and neurosurgical procedures, though it reflects the fact that the spine is comprised of multiple levels that are subject to continued degeneration following a focal intervention. Accurate reoperation rate data are important for patients making treatment decisions. Somewhat surprisingly, there were no important patient or disease characteristics that predicted an increased risk of reoperation. While there may be some unmeasured and poorly understood factors (i.e. severity of degenerative change, intervertebral mobility, genetics, etc.) that do predict reoperation, the results suggest that most SpS patients who meet the strict indications for surgery laid out in SPORT have similar risk for reoperation. Further details about the indications for reoperation, levels involved, and the use of fusion would have been helpful as would have patient reported outcomes following the revision surgery. While future studies may provide some of these data, the current study represents a relatively large, homogenous group of SpS patients that will be difficult to recreate again.

Please read Dr. Gerling's article on this topic in the May 1 issue. Does this change how you view the risk of reoperation following surgery for SpS? Let us know by leaving a comment on The Spine Blog.

Adam Pearson, MD, MS

Associate Web Editor


Friday, April 29, 2016

The role of vertebroplasty (VP) remains poorly defined. Some physicians have suggested that it should be used more frequently for acute, painful fractures,1 while others think it should rarely if ever be used based on the results of two randomized trials that showed no benefit compared to a sham procedure2,3 Those trials have been criticized for including primarily patients who had fractures over six weeks old and some with relatively mild symptoms. Many prior studies without a sham control have shown a benefit of VP, and anecdotal evidence suggests that VP helps some patients. On the other hand, the vast majority of compression fractures will go onto heal uneventfully with minimal or no treatment over the course of 6-10 weeks. Given that most evidence on this topic has looked at outcomes for patients with subacute or chronic fractures, Dr. Yang and colleagues from Shanghai performed a non-blinded RCT comparing VP to conservative management, which included at least two weeks of bedrest followed by mobilization with bracing. All patients had acute compression fractures, with the average symptom duration prior to enrollment being 5.5 days. They randomized 135 patients, with 107 remaining compliant with their treatment assignment and completing 1 year follow-up. The VP group had better outcomes on VAS back pain, Oswestry Disability Index (ODI), and a measure specific to osteoporotic compression fractures (QUALEFFO). In the year following enrollment, 9% of VP patients and 8% of conservatively treated patients sustained at least 1 more compression fracture. The authors reported no technical complications related to VP but did note a higher rate of complications related to immobilization (i.e. pneumonia, DVT, UTI, depression, etc.) in the conservative treatment group (35% vs. 16%).

 

Similar to other non-blinded, randomized trials comparing VP to conservative treatment, this study showed a significant advantage for VP.1 Physicians now have to reconcile conflicting data between the non-blinded RCTs favoring VP and the blinded, sham-controlled RCTs that showed minimal or no benefit to VP. Aside from the lack of blinding, this study differed in two important ways from the sham-controlled trials. All patients in the current trial had acute fractures, with vertebroplasty being performed at an average of 3 days following diagnosis and 8 days after the onset of symptoms. Additionally, the control group in the current study was very different, with patients being prescribed a minimum of 2 weeks of bedrest, with the average patient spending 33 days at bedrest. In the United States, only a small proportion of patients require any bedrest at all, and patients are generally encouraged to mobilize as soon as possible. Two weeks of bedrest is certainly not the standard of care, and prescribing such a treatment would be considered bordering on malpractice. Given that prolonged bedrest is not a recommended treatment and is known to be associated with many complications and deconditioning, the advantages observed for VP in this trial may be due less to the benefits of VP and more related to the negative effects of prolonged bedrest. Additionally, while VP may provide faster resolution of pain than the natural history, by 6-10 weeks most fractures should be healed, and it seems unlikely that VP should result in much advantage beyond 3 months. At longer term follow-up, the advantage of VP is likely due to either the placebo effect or the negative results of prolonged bedrest. The authors seem to conclude that VP should be used more frequently for patients with acute osteoporotic compression fractures, but that conclusion is not supported by the evidence. What all of the VP studies have demonstrated is that we do not know which patients benefit most from the intervention. Patients who are bedbound by acute fractures and those who are severely limited by subacute fractures seem like two groups who are likely to benefit from VP, but these subgroups have not been well-studied. Until further studies better define the patients who stand to benefit from VP, physicians will continue to rely on intuition rather evidence while helping patients make this treatment decision.

 

Please read Dr. Yang's article on this topic in the April 15 issue. Does it change how you view the role of vertebroplasty? Let us know by leaving a comment on The Spine Blog.

 

Adam Pearson, MD, MS

Associate Web Editor

 

REFERENCES

 

1.            Farrokhi MR, Alibai E, Maghami Z. Randomized controlled trial of percutaneous vertebroplasty versus optimal medical management for the relief of pain and disability in acute osteoporotic vertebral compression fractures. J Neurosurg Spine 2011;14:561-9.

2.            Buchbinder R, Osborne RH, Ebeling PR, et al. A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures. N Engl J Med 2009;361:557-68.

3.            Kallmes DF, Comstock BA, Heagerty PJ, et al. A randomized trial of vertebroplasty for osteoporotic spinal fractures. N Engl J Med 2009;361:569-79.

 

 


Friday, April 22, 2016

The role of fusion in degenerative spondylolisthesis (DS) was hotly debated in the 1990s, when two studies were performed suggesting that patients undergoing fusion in addition to laminectomy had better outcomes and less progression of listhesis than patients undergoing laminectomy alone.1,2 Based largely on the results of these studies, laminectomy and fusion became the standard treatment for DS, and over 95% of DS patients undergoing surgery in the United States now undergo a fusion.3 More recently, the role of fusion has been questioned, especially as less invasive decompressive techniques have been developed.4 As a result, two recent RCTs were performed, with the results published in the New England Journal of Medicine last week. Forsth et al. reported the results of the Swedish Spinal Stenosis Study (SSSS), which included 247 patients, 135 of whom had DS.5 They randomized patients to either decompression alone (D) or decompression and fusion (DF). Ghogawala et al. performed the Spinal Laminectomy vs. Instrumented Pedicle screw (SLIP) study that similarly randomized 66 DS patients to D or DF. The primary outcome in the SSSS was the Oswestry Disability Index (ODI) at two year follow-up. There were no significant differences on this outcome (16 point improvement in DF group, 20 point improvement in D group), or any other patient reported outcome, through 5 years of follow-up. In the SLIP trial, the SF-36 Physical Component Summary (PCS) at 2 years was the primary outcome measure, and the DF group improved by about 6 points more than the D group (a clinically and statistically significant difference). Additionally, the 4 year reoperation rate was 34% in the D group (all repeat surgeries were at the index level) and 14% in the DF group (all repeat surgery at adjacent levels). In contrast, reoperation rates in the SSSS were the same for the two groups (22% D vs. 21% DF over 6.5 years). The SLIP trial also evaluated ODI scores and reported an improvement of 26 points in the DF group vs. 18 in the D group at 2 years (p=0.06). The authors of the two studies reached essentially opposite conclusions, with the SSSS concluding that there was no advantage of fusion, while the SLIP trial determined that fusion both improved clinical outcome measures and reduced reoperation rate.

These studies present a conundrum for the practicing spine surgeon, since they both appeared to use similar methodologies to study the same question, yet reached substantially different conclusions. The patients in the two studies seem quite similar at baseline and had similar operations. The main driver in the difference in ODI improvement at 2 years was that the DF group in the SLIP trial improved substantially more than the DF group in the SSSS (26 vs. 20 points). The outcomes for the D group in the two studies was similar (18 points SLIP vs. 20 points SSSS). The degree of ODI improvement at 2 years in the SLIP trial DF group was similar to that observed in the DS surgical group in the Spine Patient Outcomes Research Trial (SPORT, 24 points), with the vast majority of these patients undergoing DF.6 It is unclear what was driving these moderate differences in outcomes in the DF groups between the American and Swedish studies, though there may be unmeasured differences in the patient population or unreported differences in surgical techniques. There may also be cultural or language differences that affect how patients report their outcomes. For example, among DS patients undergoing DF, 89% of the SPORT patients reported satisfaction with their outcomes compared to 64% in the SSSS. The differences in reoperation rates also raise questions. While the reoperation rates in the SSSS were similar for the two treatment groups, the reoperation rate was over twice as high for the D group compared to the DF group in the SLIP trial. While there was no D group in the SPORT DS study, the 4 year reoperation rate among the DF fusion patients was 15%, nearly identical to the DF patients in the SLIP trial (14%). Reoperation rate is a difficult outcome measure to interpret, as it reflects the subjective preferences of the surgeons and patients involved in the treatment decision. It would have been nice to have patient reported outcome data on the patients undergoing reoperation both before and after the revision surgery. Even after thorough analysis of these papers, it may not be possible to completely explain the differences in outcomes. A superficial explanation may simply be that American and Swedish patients and surgeons are different, and the results in one nation may not generalize to the other. These studies do reinforce the concept that DS represents a wide spectrum of disease that affects a heterogeneous patient population. We currently tend to treat DS with a one size fits all approach, with the majority of patients in the United States undergoing a laminectomy and instrumented posterolateral fusion (with or without interbody support). These studies reinforce that some DS patients do not derive much benefit from a fusion, and different surgical techniques may be best suited to different patient populations. Unfortunately, there is no scientific data to guide surgical technique selection in DS based on individual patient characteristics. Until there is, many surgeons will likely continue to perform decompression and fusion in an effort to avoid a difficult revision surgery at the index level. At the same time, surgeons may be more comfortable performing a laminectomy alone in older patients with medical comorbidities with stable appearing slips.

 

While these studies were not published in Spine, they are of great interest to the Spine readership. Do they change how you approach selecting a surgical technique in DS? Let us know by leaving a comment on The Spine Blog.


Adam Pearson, MD, MS

Associate Web Editor

 

REFERENCES

1.            Bridwell KH, Sedgewick TA, O'Brien MF, Lenke LG, Baldus C. The role of fusion and instrumentation in the treatment of degenerative spondylolisthesis with spinal stenosis. J Spinal Disord 1993;6:461-72.

2.            Herkowitz HN, Kurz LT. Degenerative lumbar spondylolisthesis with spinal stenosis. A prospective study comparing decompression with decompression and intertransverse process arthrodesis. The Journal of bone and joint surgery 1991;73:802-8.

3.            Kepler CK, Vaccaro AR, Hilibrand AS, et al. National trends in the use of fusion techniques to treat degenerative spondylolisthesis. Spine (Phila Pa 1976) 2014;39:1584-9.

4.            Joaquim AF, Milano JB, Ghizoni E, Patel AA. Is There a Role for Decompression Alone for Treating Symptomatic Degenerative Lumbar Spondylolisthesis?: A Systematic Review. J Spinal Disord Tech 2015.

5.            Forsth P, Olafsson G, Carlsson T, et al. A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis. N Engl J Med 2016;374:1413-23.

6.            Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis. The New England journal of medicine 2007;356:2257-70.

 

 

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Spine Journal
This Blog provides a forum for discussion about high impact articles published in Spine, including the bi-annual publication of "Evidenced-Based Recommendations for Spine Surgery." Website users can use this forum to discuss how the articles have affected their practice and query the authors about their findings and recommendations.