Archive | spine RSS for this section

JBJS Classics: Wiltse’s Paraspinal Muscle-Splitting Approach

JBJS Classics Logo.pngOrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation by clicking on the “Leave a Comment” button in the box to the left.

Almost 50 years ago, in a classic 1968 JBJS paper, Leon Wiltse and co-authors described a novel and innovative access route to the lumbar spine. At that time, the vast majority of approaches to the lumbar spine were performed through midline incisions. Wiltse´s approach, however, utilized a more lateral access route to the spine. In this beautifully illustrated paper, the authors described a curved incision of the fascia and the skin with direct access to the transverse processes, pedicles, and the lateral masses.

The advantages of this novel access were multifold. Although wide midline laminectomies represented the gold-standard decompression technique at that time, the lateral approach served to avoid a more challenging and risky midline revision access, adding an elegant access for salvage procedures. Two goals of Wiltse’s approach were to achieve solid, posterolateral fusions and to decompress the neural structures. Graft harvest from the posterior iliac crest was easily facilitated with this approach.

Additional advantages included reduced blood loss and less muscle ischemia, and the preservation of spinous processes and intra-/supraspinous ligaments, which served to maintain the stability of the lumbar spine. The main downside was the necessity of performing two skin incisions as opposed to just one midline incision.

Since its introduction, Wiltse´s approach and the anatomic planes have been studied in great detail.1,2 Considering the vast developments in spine surgery over the last years and decades, the Wiltse approach has stood the test of time, as it still represents one of the main access routes to the lumbar spine that any skilled spine surgeon needs to master.

With the arrival of instrumentation, Wiltse´s approach was later employed in interbody fusion and minimally invasive transforaminal lumbar interbody fusion (TLIF) techniques, as it allowed direct access to the pedicles and the disc space. It has also been used for various techniques of direct pars repair.3

With the addition of some minor modifications, Wiltse´s approach still reflects the main access for minimally invasive, microsurgical treatment of foraminal and extraforaminal disc herniations, including bony decompression of the neuroforamen.4 The far lateral access permits sufficient decompression of the exiting nerve roots while preserving the facet joints, which serves to avoid more invasive fusion techniques for a considerable number of patients.

Overall, Wiltse´s innovative approach advanced spinal care by reducing access–related morbidity. Dr. Wiltse passed away at age 92 in 2005. His major achievements in spine surgery and his great accomplishments will remain in our memories and will continue to impact spine surgery over the coming decades.

Christoph J. Siepe, MD
JBJS Deputy Editor

References

  1. Vialle R, Court C, Khouri N, et al. Anatomical study of the paraspinal approach to the lumbar spine. Eur Spine J. 2005;14(4):366-71.
  2. Palmer DK, Allen JL, Williams PA, et al. Multilevel magnetic resonance imaging analysis of multifidus-longissimus cleavage planes in the lumbar spine and potential clinical applications to Wiltse’s paraspinal approach. Spine (Phila Pa 1976). 2011;36(16):1263-7.
  3. Xing R, Dou Q, Li X, et al. Posterior Dynamic Stabilization With Direct Pars Repair via Wiltse Approach for the Treatment of Lumbar Spondylolysis: The Application of a Novel Surgery. Spine (Phila Pa 1976). 2016;41(8):E494-502.
  4. Mehren C, Siepe CJ. Neuroforaminal decompression and intra-/extraforaminal discectomy via a paraspinal muscle-splitting approach. Eur Spine J. 2016.

JBJS JOPA Image Quiz: Incomplete Spinal Cord Injury

Lateral_Spine.pngThis month’s Image Quiz from the JBJS Journal of Orthopaedics for Physician Assistants (JOPA) presents the case of a 55-year-old woman with neck pain and upper-extremity weakness after a motor vehicle accident that occurred 1 week prior, during which she sustained a whiplash injury.  She notes severe bilateral arm weakness, “clumsy hands,” and mild lower-extremity weakness with walking. The bilateral upper-extremity muscle groups have a strength of 3 of 5, and the lower-extremity muscle groups have a strength of 5 of 5. Sensation remains intact throughout the upper and lower extremities.

Select from among four choices as the most likely diagnosis:

  1. Central cord syndrome
  2. Brown-Séquard syndrome
  3. Anterior cord syndrome
  4. Posterior cord syndrome

Guest Post: Own the Bone Improves Osteoporosis Care

ownbone_logo-r.pngOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Brett A. Freedman, MD.

In the December 21, 2016 edition of the Journal of Bone & Joint Surgery, Bunta, et al. published an analysis of data from the Own the Bone quality improvement program collected between January 1, 2010 and March 31, 2015. Over this period of time, 125 sites prospectively collected detailed osteoporosis and bone health-related data points on men and women over the age of 50 who presented with a fragility fracture.

The Own the Bone initiative is more than a data registry; it’s a quality improvement program intended to provide a paradigm for increasing the diagnostic and therapeutic recognition (i.e. “response rate”) of the osteoporosis underlying fragility fractures among orthopaedic practices that treat these injuries.  With more than 23,000 individual patients enrolled, and almost 10,000 follow-up records, this is the most robust dataset in existence on the topic.

This initiative has more than doubled the response rate among orthopaedic practices treating fragility fractures. The number of institutions implementing Own the Bone grew from 14 sites in 2005-6 to 177 in 2015. According to Bunta et al., 53% of patients enrolled in the Own the Bone quality Improvement program received bone mineral density testing and/or osteoporosis therapy following their fracture.

Own the Bone was a natural progression of rudimentary efforts that came about during the Bone and Joint Decade, and it marks a strategic effort on the part of the American Orthopedic Association to identify and treat the osteoporosis underlying fragility fractures.  Multiple studies have demonstrated that only 1 out of every 4 to 5 patients who present with a fragility fracture will receive a clinical diagnosis of osteoporosis and/or active treatment to prevent secondary fractures related to osteoporosis. Ample Level-1 evidence demonstrates that the initiation of first-line agents like bisphosphonates, or second-line agents when indicated, can reduce the chance of a subsequent fragility fracture by at least 50%.  We know these medicines work.

We also know that osteoporosis is a progressive phenomenon. Therefore, failing to respond to the osteoporosis underlying fragility fractures means we as a medical system fail to treat the root cause in these patients. The fracture is a symptom of an underlying disease that needs to be addressed or it will continue to produce recurrent fractures and progressive decline in overall health.

The members of the Own the Bone initiative must be commended for their admirable work. We as an orthopedic community need to attempt to incorporate lessons learned through the Own the Bone experience into our practice to ensure that we provide complete care to those with a fragility fracture. The report from Bunta et al. represents a large—but single—step forward on the journey toward universal recognition and treatment of the diminished bone quality underlying fragility fractures. I look forward to additional reports from this group detailing their continued success in raising the bar of understanding and intervention.

Brett A. Freedman, MD is an orthopaedic surgeon specializing in spine trauma and degenerative spinal diseases at the Mayo Clinic in Rochester, MN.

JBJS Editor’s Choice: Improving Function After Fragility Fractures

hip_fracture_drugs_11_16_16In the past several years, the orthopaedic community has become highly engaged in improving the follow-up management of patients presenting with fragility fractures. We have realized that orthopaedic surgeons are central to the ongoing health and welfare of these patients and that the episode of care surrounding a fragility fracture represents a unique opportunity to get patients’ attention. Using programs such as the AOA’s “Own the Bone” registry, increasing numbers of orthopaedic practices and care centers are leading efforts to deliver evidenced-based care to fragility-fracture patients.

In the November 16, 2016 edition of The Journal, Aspenberg et al. carefully examine the impact of the anabolic agent teriparatide versus the bisphosphonate risedronate on the 26-week outcomes of more than 170 randomized patients (mean age 77 ±8 years) who were treated surgically for a low-trauma hip fracture. This investigation is timely and appropriate because our systems of care are evolving so that increasing numbers of patients are receiving pharmacologic intervention for low bone density both before and after a fragility fracture.

The secondary outcomes of the timed up and go (TUG) test and post-TUG test pain were better in the teriparatide group, but there were no differences in radiographic fracture healing or patient-reported health status.

Although this study was designed primarily to measure the effects of the two drugs on spinal bone mineral density at 78 weeks, these secondary-outcome findings confirm the value of initiating pharmacologic intervention early on after a fragility fracture, whether it’s a bisphosphonate or anabolic agent. The orthopaedic community needs to continue leading multipronged efforts to deal with the public health issues of osteoporosis and fragility fractures.

Click here for additional OrthoBuzz posts related to osteoporosis and fragility fractures.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Cardiopulmonary Effects of Scoliosis

ventilation-scatterplot_10_5_16The 3-dimensional spinal deformities associated with scoliosis may affect other organ systems. In the October 5, 2016 issue of The Journal, Shen et al. correlated radiographic severity of thoracic curvature/kyphosis with pulmonary function at rest and exercise capacity measured with a bicycle ergometer. Forty subjects with idiopathic scoliosis were enrolled in the prospective study (mean age 15.5 years), 33 of them female.

The study found no correlation between coronal thoracic curvature and static pulmonary function tests in the female patients. Female patients with a thoracic curve of ≥ 60° had lower blood oxygen saturation at maximal exertion during the exercise test, but overall exercise tolerance did not appear to be correlated with the magnitude of the thoracic curve and kyphosis. According to the authors, taken together, the many specific cardiopulmonary findings in this study suggest that “the cardiovascular system may be less affected than the respiratory system in patients with idiopathic scoliosis.”

Not surprisingly, exercise capacity was better in patients who performed regular aerobic exercise. Although physical training may not be able to change pulmonary pathology in this population, the authors emphasized that physical activity is still recommended for patients with idiopathic scoliosis for maintaining cardiovascular and peripheral muscle conditioning.

Are Ortho Patients Getting Too Many Pain Pills?

narc_usage_2016-10-03Surgeons often prescribe more postoperative pain medication than their patients actually use. That’s partly because there is limited procedure-specific evidence-based data regarding optimal amounts and duration of postoperative narcotic use—and because every patient’s “relationship” with postoperative pain is unique. Nevertheless, physician prescribing plays a role in the current opioid-abuse epidemic, so any credible scientific information about postoperative narcotic usage will be helpful.

The Level I prognostic study by Grant et al. in the September 21, 2016 issue of The Journal of Bone & Joint Surgery identified factors associated with high opioid use among a prospective cohort of 72 patients (mean age 14.9 years) undergoing posterior spinal fusion for idiopathic scoliosis.

Higher weight and BMI, male sex, older age, and higher preoperative pain scores were associated with increased narcotic use after surgery. Somewhat surprisingly, the number of levels fused, number of osteotomies, in-hospital pain level, self-reported pain tolerance, and surgeon assessment of anticipated postoperative narcotic requirements were unreliable predictors of which patients would have higher postoperative narcotic use.

Because the authors found that pain scores returned to preoperative levels by postoperative week 4, they say, “further refills after this point should be considered with caution.” Additionally, after reviewing the cohort’s behavior around disposing of unused narcotic medication, the authors conclude, “We consider discussion of narcotic use and disposal to be an important component of the 1-month postoperative visit…This important educational opportunity could help decrease abuse of narcotics.”

Long-Term Revision Rates after Cervical Spine Arthrodesis

cervical-arthrodesisMost studies looking into revision rates after cervical spine fusion follow patients for 2 to 5 years. But in the September 21, 2016 issue of JBJS, Derman et al. investigate revision rates—and risk factors for revision—with a follow-up of 16 years.

Analyzing New York State’s SPARCS all-payer database, the authors identified more than 87,000 patients who underwent a primary subaxial cervical arthrodesis from 1997 through 2012. During the study period, 7.7% of the patients underwent revision, with a median time to revision of 24.5 months.

Cervical arthrodeses performed with anterior-only approaches had a significantly higher probability of revision than those performed via posterior or circumferential approaches. The authors also found that the following characteristics were associated with an elevated revision risk:

  • Patient age of 18 to 34 years
  • White race
  • Workers’ Compensation or Medicare (but not Medicaid) coverage
  • Arthrodeses to address spinal stenosis, spondylosis, deformity, or neoplasm

Shorter arthrodeses (i.e., fewer fusion levels) and arthrodesis to address fractures were associated with relatively lower revision risks.

The authors conclude that “knowledge of these factors should help to promote exploration of strategies to reduce the prevalence of revision(s)…and to facilitate more accurate preoperative counseling of patients.”

JBJS Classics: The Natural History of Congenital Scoliosis

jbjsclassics-2016OrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation about these classics by clicking on the “Leave a Comment” button in the box to the left.

Michael McMaster, a widely respected and well-published orthopaedic surgeon from Edinburgh who treated a great number of pediatric spinal deformity patients over a 36-year career, published this classic JBJS article more than 30 years ago. His report continues to serve as the basis for what we as pediatric spinal deformity surgeons recommend for treatment in children with congenital scoliosis. The classification that he proposed allows us to know early in childhood which congenital scoliosis patients require early, aggressive treatment and who can be followed with little need for treatment.

By assessing 251 growing patients with congenital scoliosis in a longitudinal manner, Mr. McMaster determined the rate of progression with growth for 5 different primary curve types. The most progressive deformity is a unilateral vertebral bar (failure of segmentation) with a contralateral hemivertebra (failure of formation). Common congenital single hemivertebrae worsen most in the thoracolumbar and lower thoracic areas, and all hemivertebrae progress at a faster rate after 10 years of age than prior to age 10.

Knowing the natural history of any deformity in pediatric orthopaedics is the major factor in determining the need for treatment.  Mr. McMaster here provided the pediatric spinal deformity surgeon with essential information that still guides our treatment of congenital scoliosis on a daily basis today.

Vernon T. Tolo, MD
JBJS Editor Emeritus

Guest Post: Osteoporosis Treatment Still Lacking

OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Brett A. Freedman, MD, in response to a study published in JAMA about a new agent to prevent fractures in postmenopausal women with osteoporosis.

The August 16, 2016 issue of JAMA published the results of the ACTIVE (Abaloparatide Comparator Trial In Vertebral Endpoints) trial.  This 28-site randomized trial allocated postmenopausal women with low bone mineral density (BMD) and/or a prior fragility fracture into one of three arms:  abaloparatide (80 µg subcutaneously, daily ) vs. daily placebo injection vs. teriparatide (20 µg subcutaneously, daily).  The primary end point was new vertebral fracture over the 18-month trial.

As expected, both anabolic agents significantly outperformed placebo, with incident vertebral fractures occurring in only 4 subjects in the abaloparatide arm (0.6%) and 6 in the teriparatide arm (0.8%), while there were 30 in the placebo arm (4.2%).  Although the study was not powered to evaluate differences between the two anabolic agents, the results suggest that abaloparatide and teriparatide performed essentially the same over the 18-month period.

In an accompanying commentary,1 Cappola and Shoback note that institutional review boards (IRBs) approved a prospective clinical trial protocol in which patients with known osteoporosis and/or a prior fragility fracture were allowed to be randomized to a non-treatment arm for 18 months.  Subjects whose BMD dropped more than 7% from baseline and those who experienced an incident fracture during the trial “were offered an option to discontinue and receive alternative treatment,” but in some sense IRB approval of this protocol implicitly acknowledged that osteoporosis is undertreated.

Turning back to the study itself, I noted with interest that subjects who had regularly used bisphosphonates in the last 5 years or denosumab in the last year were excluded.  So, none of the 2463 subjects who were randomized had received any active treatment for osteoporosis in the 1 to 5 years prior to enrollment, despite the fact that the average T-score in the lumbar spine (-2.9 for all 3 arms) was in the osteoporotic range and that almost one-third of subjects had had at least one prior fragility fracture.

This is a sad commentary on “our” (meaning all providers involved in bone health) continued inability to diagnose and treat osteoporosis effectively.  Despite the “National Bone and Joint Health Decade” (2002-2011) and our continued attempts to “Own the Bone,” we have made little progress in recognizing and treating the osteoporosis underlying the fragility fractures that we so frequently treat.  Colleagues of mine and I published that only 38% of patients in 2002 with clinically diagnosed vertebral compression fragility fractures were receiving active treatment for osteoporosis.2  Over the ensuing decade, Solomon et al. showed that that figure actually decreased to 20%.3

This JAMA study provides empiric Level-I support for the efficacy of another anabolic agent to treat osteoporosis.  Cost, subcutaneous delivery, and osteosarcoma concerns have limited the only FDA-approved anabolic osteoporosis medication, teriparatide, to second-line status, behind bisphosphonates.  If and when approved, abaloparatide will probably bump up against the same limitations.  Still, the parathyroid hormone receptor agonists are particularly pertinent to orthopaedic surgeons, because they are the most effective secondary fracture prevention agents—and the only ones that show meaningful improvement in bone mineral density.  This bone-building property has also led to progressive acceptance of teriparatide as an important perioperative adjunct for instrumented spinal fusion surgery in patients with known osteoporosis.

However, as has been repeatedly shown, parathyroid receptor agonists only work when they are prescribed, and they are only prescribed when osteoporosis is diagnosed.2,3  Patients with incident clinical fragility fractures need to be effectively educated about osteoporosis, its treatment, and the impact of failing to treat it.  Orthopaedic surgeons need to continue to set the signal flares and advocate for our patients to receive effective treatment for all their chronic musculoskeletal illnesses, not the least of which is osteoporosis.

References:

  1. Cappola AR, Shoback DM. Osteoporosis Therapy in Postmenopausal Women With High Risk of Fracture. JAMA. 2016 Aug 16;316(7):715-6.
  1. Freedman BA, Potter BK, Nesti LJ, Giuliani JR, Hampton C, Kuklo TR. Osteoporosis and vertebral compression fractures-continued missed opportunities.Spine J. 2008 Sep-Oct;8(5):756-62.
  1. Solomon DH, Johnston SS, Boytsov NN, McMorrow D, Lane JM, Krohn KD. Osteoporosis medication use after hip fracture in U.S. patients between 2002 and 2011. J Bone Miner Res. 2014 Sep;29(9):1929-37.

Could Bundled Payments Work with Cervical Fusion?

ACDF_Reimbursement_VariationThe answer to that question depends largely on how much the 90-day episode of care actually costs. Virk et al., in the August 17, 2016 edition of JBJS, provide benchmark data that could help policymakers design bundled payments for cervical fusions that are economically viable for providers.

The authors analyzed the Medicare 5% National Sample Administrative Database and found that 4,506 patients in that cohort underwent a one to two-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy from 2005 to 2012. The mean cost per patient of the procedure plus the 90-day postoperative period was $15,417. The physician reimbursement represented 20.4% of that total, with the surgeon receiving 18% of the total. Reimbursements for hospitals for inpatient care represented nearly 73% of the total reimbursement. The study did not account for reimbursements from “Medigap” plans or private payers.

The authors also analyzed data from the same database for 90-day episodes of care related to total knee arthroplasty (TKA). The mean per-patient reimbursement for TKA patients was $17,451. The authors noted significant regional variation in reimbursement for ACDF, with the lowest rates in the Northeast and Midwest and the highest rates in the West.

Among the conclusions made by Virk et al. is the following: “Although payments to physicians have been implicated in the rise of health-care costs, the data suggest that the greater opportunity for reducing expenses involves hospital-related reimbursement.”

Click here for more OrthoBuzz coverage of bundled payments in orthopaedics.