How closely are outcome questionnaires correlated to patient satisfaction after cervical spine surgery for myelopathy?

OBJECTIVE

Patient-reported outcomes (PROs) have become the standard means to measure surgical outcomes. Insurers and policy makers are also increasingly utilizing PROs to assess the value of care and measure different aspects of a patient's condition. For cervical myelopathy, it is currently unclear which outcome measure best reflects patient satisfaction. In this investigation, the authors evaluated patients treated for cervical myelopathy to determine which outcome questionnaires best correlate with patient satisfaction.

METHODS

The Quality Outcomes Database (QOD), a prospectively collected multi-institutional database, was used to retrospectively analyze patients undergoing surgery for cervical myelopathy. The North American Spine Society (NASS) satisfaction index, Neck Disability Index (NDI), numeric rating scales for neck pain (NP-NRS) and arm pain (AP-NRS), EQ-5D, and modified Japanese Orthopaedic Association (mJOA) scale were evaluated.

RESULTS

The analysis included 1141 patients diagnosed with myelopathy, of whom 1099 had an NASS satisfaction index recorded at any of the follow-up time points. Concomitant radiculopathy was an indication for surgery in 368 (33.5%) patients, and severe neck pain (NP-NRS ≥ 7) was present in 471 (42.8%) patients. At the 3-month follow-up, NASS patient satisfaction index scores were positively correlated with scores for the NP-NRS (r = 0.30), AP-NRS (r = 0.32), and NDI (r = 0.36) and negatively correlated with EQ-5D (r = -0.38) and mJOA (r = -0.29) scores (all p < 0.001). At the 12-month follow-up, scores for the NASS index were positively correlated with scores for the NP-NRS (r = 0.44), AP-NRS (r = 0.38), and NDI (r = 0.46) and negatively correlated with scores for the EQ-5D (r = -0.40) and mJOA (r = -0.36) (all p < 0.001). At the 24-month follow-up, NASS index scores were positively correlated with NP-NRS (r = 0.49), AP-NRS (r = 0.36), and NDI (r = 0.49) scores and negatively correlated with EQ-5D (r = -0.44) and mJOA (r = -0.38) scores (all p < 0.001).

CONCLUSIONS

Neck pain was highly prevalent in patients with myelopathy. Notably, improvement in neck pain-associated disability rather than improvement in myelopathy was the most prominent PRO factor for patients. This finding may reflect greater patient concern for active pain symptoms than for neurological symptoms caused by myelopathy. As commercial payers begin to examine novel remuneration strategies for surgical interventions, thoughtful analysis of PRO measurements will have increasing relevance.

Correlation of the Modified Japanese Orthopedic Association With Functional and Quality-of-Life Outcomes After Surgery for Degenerative Cervical Myelopathy: A Quality Outcomes Database Study

BACKGROUND

The modified Japanese Orthopedic Association (mJOA) score is a widely used and validated metric for assessing severity of myelopathy. Its relationship to functional and quality-of-life outcomes after surgery has not been fully described.

OBJECTIVE

To quantify the association of the mJOA with the Neck Disability Index (NDI) and EuroQol-5 Dimension (EQ-5D) after surgery for degenerative cervical myelopathy.

METHODS

The cervical module of the prospectively enrolled Quality Outcomes Database was queried retrospectively for adult patients who underwent single-stage degenerative cervical myelopathy surgery. The mJOA score, NDI, and EQ-5D were assessed preoperatively and 3 and 12 months postoperatively. Improvement in mJOA was used as the independent variable in univariate and multivariable linear and logistic regression models.

RESULTS

Across 14 centers, 1121 patients were identified, mean age 60.6 ± 11.8 years, and 52.5% male. Anterior-only operations were performed in 772 patients (68.9%). By univariate linear regression, improvements in mJOA were associated with improvements in NDI and EQ-5D at 3 and 12 months postoperatively (all P < .0001) and with improvements in the 10 NDI items individually. These findings were similar in multivariable regression incorporating potential confounders. The Pearson correlation coefficients for changes in mJOA with changes in NDI were -0.31 and -0.38 at 3 and 12 months postoperatively. The Pearson correlation coefficients for changes in mJOA with changes in EQ-5D were 0.29 and 0.34 at 3 and 12 months.

CONCLUSION

Improvements in mJOA correlated weakly with improvements in NDI and EQ-5D, suggesting that changes in mJOA may not be a suitable proxy for functional and quality-of-life outcomes.

Perioperative Complications of Cervical Spine Surgery: Analysis of a Prospectively Gathered Database through the Association for Collaborative Spinal Research

Study Design Retrospective review of prospectively gathered data. Objective To report the rate and impact of perioperative complications in cervical spine surgery. To our knowledge, no prior study of the cervical spine has analyzed a large prospectively gathered data set for adverse events, based on surgical subgroup. Methods The ProSTOS database features prospectively documented perioperative adverse events for 1,269 patients who had cervical spine surgery at multiple centers in North America between 2008 and 2011. We subgrouped patients by approach, whether surgery was a primary or revision operation, and by the number of levels involved. Multivariate analysis with stepwise logistic regression was used to relate complication rates to gender, age, smoking status, body mass index, approach, revision status, and number of levels involved. Follow-up was 41%. Results Adverse events occurred significantly more frequently in posterior and combined procedures than in anterior procedures. Revision surgery had significantly more complications than primary surgery. For patients who had anterior surgery, those who had one, two, and three or more levels operated had no significant difference in complication rates. Patients who had posterior surgery had significantly more complications if they had two or more levels operated compared with one level. The lowest rates of complications were for one-level primary surgery (<5%), and multilevel posterior, revision posterior, and revision combined surgery had complication rates over 6 times higher (>28%). Patients who had complications were significantly older than patients who did not. The most common adverse events were dysphagia and cardiac complications. The most severe morbid complications, in terms of increased treatment needs and hospital stay, were paraparesis and seizure. Conclusions Perioperative complication rates in cervical spine surgery are significantly lower in younger patients, surgery performed through an anterior approach (compared with a posterior or combined approach), with fewer levels involved (particularly in posterior surgery), and in primary (compared with revision) procedures.

THE DECISION-MAKING PROCESS

THE DECISION WHETHER to use allograft or autograft in ventral cervical fusions has been widely discussed. The literature includes several prospective randomized trials. Extensive clinical evidence indicates that autograft use results in increased arthrodesis rates and less graft collapse. However, autograft harvest has a substantial morbidity rate. Allografts avoid the morbidity associated with autograft harvest but result in decreased arthrodesis rates and increased graft collapse rates. The decreased arthrodesis rate associated with allografts becomes more significant in multilevel surgery and in patients who smoke. The introduction and use of ventral cervical plates have made allograft use more attractive by increasing arthrodesis rates and decreasing graft collapse.

Anterior cervical discectomy and fusion involving a polyetheretherketone spacer and bone morphogenetic protein

OBJECT

The authors reviewed clinical and radiographic outcomes in patients who had undergone anterior cervical discectomy and fusion (ACDF) involving the placement of polyetheretherketone (PEEK) spacers filled with recombinant human bone morphogenetic protein (rhBMP)-2.

METHODS

Data obtained in 24 cases were retrospectively evaluated. The follow-up period ranged from 12 to 16 months (mean 13 months). Fifteen patients presented with radiculopathy, eight with myeloradiculopathy, and one with quadriparesis. Single-level ACDF was performed in 12 patients, two-level ACDF in nine, and three-level ACDF in three. Clinical outcomes were assessed using Odom criteria, and fusion was assessed by examining flexion-extension radiographs and computerized tomography scans in cases in which arthrodesis was questionable. Follow-up data were available for 23 patients. One patient died of medical complications unrelated to surgery 4 weeks after ACDF. Clinical outcomes were rated as good/excellent in 22 patients (95%) and fair in one (5%). Solid radiographically documented fusion, with evidence of solid bridging bone and no instability on flexion-extension x-ray films, was present in all cases. Complications included transient recurrent laryngeal nerve injury in one case, transient C-5 paresis in one, cerebrospinal fluid leakage in one, and transient dysphagia in two.

CONCLUSIONS

Analysis of the results indicated that ACDF involving an rhBMP-2-filled PEEK spacer leads to good clinical outcomes (by Odum criteria) and solid fusion (even in multilevel cases) while avoiding the complications associated with harvesting iliac crest bone grafts.

The use of bioabsorbable implants in the spine

BACKGROUND CONTEXT

Bioabsorbable implants are commonplace in sports medicine surgeries, especially in shoulder and knee ligamentous reconstruction. Their use is now expanding to the realm of spinal reconstructive surgery. Newer polymers offer reduced incidence of the side effects of aseptic sterile sinus formation and have appropriate resorption time parameters for spine use. These new bioabsorbable materials confer initial and intermediate-term stability that is adequate for stable bony healing in various applications. The majority of human clinical applications in the spine that have been documented involve bone graft harvest site reconstruction, posterior spinal graft containment, anterior interbody reconstruction and anterior cervical and lumbar spine tension band plating.

PURPOSE

The purpose of this review article is to highlight the indications and outcomes of the use of bioabsorbable implants in specific spinal applications.

STUDY DESIGN

A comprehensive literature review of the English and non-English literature on bioabsorbable implant technology.

METHODS

A comprehensive literature review was performed to gather basic science, animal and human data on the use of bioabsorbable implants in spinal surgery.

RESULTS

Bioabsorbable implants have demonstrated strength and resorption characteristics commensurate with the physiologic and biomechanical requirements of the human spinal axis. Histologic sampling has demonstrated successful time-patterned resorption accompanied by bony replacement and remodeling of intervertebral cage devices in the animal model.

CONCLUSION

Bioresorbable compounds appear to have a role in specific spinal reconstructive procedures. Their radiolucent nature improves image assessment of fusion healing, and their time-engineered resorption characteristics allow controlled dynamization in interbody and plate applications. Their widespread use and acceptance may increase dramatically as further research and clinical studies report on their safety and efficacy.

Lumbar and lumbosacral fusions using Cotrel-Dubousset pedicle screws and rods

The first 50 consecutive patients stabilized with Cotrel-Dubousset rods for lumbar or lumbosacral fusions were followed for an average of 2 years. The occurrence of fusion, maintenance of alignment, and rate of hardware complications were examined. There were 28 men and 22 women, ages 18-87 years, and 133 vertebral levels. Twenty-nine sets of 5-mm, and 21 pairs of 7-mm, rods were placed. Two hundred and sixty-eight pedicle screws were used. Forty-eight out of 50 (96%) patients demonstrated successful arthrodesis after their initial procedure. One pedicle screw became separated from the rod. No rods migrated or broke. Seven (2.6%) pedicle screws bent and 3 (1%) broke. Large and small diameter Cotrel-Dubousset rods allowed short segment lumbar and lumbosacral fusion with a high degree of reliability.

Pull-out strength of Caspar cervical screws

Anterior cervical instrumentation as an adjunct to bone fusion has an important role in cervical spine surgery. Posterior vertebral body cortex purchase is strongly recommended in the use of the Caspar system, although few biomechanical data exist to validate this requirement. In this study, Caspar screws were placed in 43 human cadaveric cervical vertebral bodies, either putting them into the posterior vertebral cortex as identified radiographically or penetrating it by 2 mm as recommended in the literature. Pull-out tests were conducted with tension applied to a connected plate at 0.25 mm/s, and force-deformation data were obtained. Failure typically occurred with clean pull-out; in most instances, cancellous bone remained attached to screw threads. Mean load without posterior cortical purchase was 375 +/- 53 N; with penetration it was 411 +/- 70 N. These differences were nonsignificant. Average deformation to failure was 1.41 +/- 0.10 mm in the group without posterior cortical penetration. In the posterior penetration group, mean deformation was 1.56 +/- 0.16 mm. Again, differences were not significant. Posterior cortical penetration does not improve the pull-out strength of Caspar screws in an isolated vertebral body model, but other biomechanical studies need to be done before insertion methods are altered.