Robert Hart

Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy Presented at the 2012 Joint Spine Section Meeting Clinical article

OBJECT Sagittal spinopelvic malalignment is a significant cause of pain and disability in patients with adult spinal deformity. Surgical correction of spinopelvic malalignment can result in compensatory changes in spinal alignment outside of the fused spinal segments. These compensatory changes, termed reciprocal changes, have been defined for thoracic and lumbar regions but not for the cervical spine. The object of this study was to evaluate postoperative reciprocal changes within the cervical spine following lumbar pedicle subtraction osteotomy (PSO). METHODS This was a multicenter retrospective radiographic analysis of patients from International Spine Study Group centers. Inclusion criteria were as follows: adults (>18 years old) with spinal deformity treated using lumbar PSO, a preoperative C7-S1 plumb line greater than 5 cm, and availability of pre- and postoperative full-length standing radiographs. RESULTS Seventy-five patients (60 women, mean age 59 years) were included. The lumbar PSO significantly improved sagittal alignment, including the C7-S1 plumb line, C7-T12 inclination, and pelvic tilt (p <0.001). After lumbar PSO, reciprocal changes were seen to occur in C2-7 cervical lordosis (from 30.8° to 21.6°, p <0.001), C2-7 plumb line (from 27.0 mm to 22.9 mm), and T-1 slope (from -38.9° to -30.4°, p <0.001). Ideal correction of sagittal malalignment (postoperative sagittal vertical alignment < 50 mm) was associated with the greatest relaxation of cervical hyperlordosis (-12.4° vs -5.7°, p = 0.037). A change in cervical lordosis correlated with changes in T-1 slope (r = -0.621, p <0.001), C7-T12 inclination (r = 0.418, p <0.001), T12-S1 angle (r = -0.339, p = 0.005), and C7-S1 plumb line (r = 0.289, p = 0.018). Radiographic parameters that correlated with changes in cervical lordosis on multivariate linear regression analysis included change in T-1 slope and change in C2-7 plumb line (r(2) = 0.53, p <0.001). CONCLUSIONS Adults with positive sagittal spinopelvic malalignment compensate with abnormally increased cervical lordosis in an effort to maintain horizontal gaze. Surgical correction of sagittal malalignment results in improvement of the abnormal cervical hyperlordosis through reciprocal changes.

Nonoperative management of dens fracture nonunion in elderly patients without myelopathy

STUDY DESIGN A retrospective review of elderly patients treated without surgery for chronic mobile nonunions of the odontoid process. Patients were observed on an annual basis with clinical examinations and flexion/extensions plain film radiographs. OBJECTIVES To evaluate the clinical and radiographic results of elderly patients without myelopathy treated without surgery for dens fracture nonunion. SUMMARY OF BACKGROUND DATA Because of the risk of progressive myelopathy or sudden neurologic injury, many surgeons recommend operative stabilization for patients with mobile dens nonunions who are able to withstand an operation. There is, however, a lack of information about the radiographic and neurologic progression of dens nonunions. Although a less aggressive surgical approach has been recommended by some authors for elderly or medically compromised patients with acute fractures, long-term follow-up evaluation of patients with resulting nonunions has not been reported. METHODS A series of elderly patients with chronic, unstable, dens nonunions without myelopathy were treated with a nonoperative treatment protocol. Patients were informed of the nature of their lesion, including the risk of acute or chronic spinal cord injury and the options for operative treatment. Patients were evaluated yearly for clinical and radiographic progression. No intervention to slow progression of atlantoaxial instability was undertaken. RESULTS None of the patients developed myelopathic symptoms during the follow-up period, and no patient experienced more than a 1 mm radiographic increase in atlantoaxial excursion. None of the reported patients had less than 14 mm available for the spinal cord in either flexion or extension at the start of clinical monitoring. CONCLUSIONS Although further follow-up evaluation is needed, the authors believe on the basis of this review that this treatment protocol may be considered for patients who are poor candidates for surgical fusion.

Outcomes of Operative and Nonoperative Treatment for Adult Spinal Deformity: A Prospective, Multicenter, Propensity-Matched Cohort Assessment With Minimum 2-Year Follow-up

BACKGROUND High-quality studies that compare operative and nonoperative treatment for adult spinal deformity (ASD) are needed. OBJECTIVE To compare outcomes of operative and nonoperative treatment for ASD. METHODS This is a multicenter, prospective analysis of consecutive ASD patients opting for operative or nonoperative care. Inclusion criteria were age >18 years and ASD. Operative and nonoperative patients were propensity matched with the baseline Oswestry Disability Index, Scoliosis Research Society-22r, thoracolumbar/lumbar Cobb angle, pelvic incidence-to-lumbar lordosis mismatch (PI-LL), and leg pain score. Analyses were confined to patients with a minimum of 2 years of follow-up. RESULTS Two hundred eighty-six operative and 403 nonoperative patients met the criteria, with mean ages of 53 and 55 years, 2-year follow-up rates of 86% and 55%, and mean follow-up of 24.7 and 24.8 months, respectively. At baseline, operative patients had significantly worse health-related quality of life (HRQOL) based on all measures assessed (P < .001) and had worse deformity based on pelvic tilt, pelvic incidence-to-lumbar lordosis mismatch, and sagittal vertical axis (P ≤ .002). At the minimum 2-year follow-up, all HRQOL measures assessed significantly improved for operative patients (P < .001), but none improved significantly for nonoperative patients except for modest improvements in the Scoliosis Research Society-22r pain (P = .04) and satisfaction (P < .001) domains. On the basis of matched operative-nonoperative cohorts (97 in each group), operative patients had significantly better HRQOL at follow-up for all measures assessed (P < .001), except Short Form-36 mental component score (P = .06). At the minimum 2-year follow-up, 71.5% of operative patients had ≥1 complications. CONCLUSION Operative treatment for ASD can provide significant improvement of HRQOL at a minimum 2-year follow-up. In contrast, nonoperative treatment on average maintains presenting levels of pain and disability. ABBREVIATIONS ASD, adult spinal deformityHRQOL, health-related quality of lifeLL, lumbar lordosisMCID, minimal clinically important differenceNRS, numeric rating scaleODI, Oswestry Disability IndexPI, pelvic incidenceSF-36, Short Form-36SRS-22r, Scoliosis Research Society-22rSVA, sagittal vertical axis.

Posterior global malalignment after osteotomy for sagittal plane deformity: it happens and here is why.

Study Design. Multicenter, retrospective analysis of 183 consecutive patients undergoing lumbar osteotomy. Objective. To evaluate cause and impact of posterior postoperative alignment. Summary of Background Data. Sagittal malalignment in the setting of adult spinal deformity (ASD) has shown significant correlation with pain and disability. Surgical treatment often entails correction of deformity by pedicle subtraction osteotomies (PSO). Key radiographical spinopelvic objectives to reach improvement in clinical outcomes have been previously reported. Although anterior alignment is a cause of poor outcomes, the impact and cause of posterior spinal alignment by PSO has not been reported. Methods. The patient inclusion criteria were age, more than 18 years, with a diagnosis of sagittal plane deformity (C7 plumbline offset >5 cm, a pelvic tilt >20°, or a lumbar lordosis to pelvic incidence mismatch of ≥10°) requiring a surgical procedure involving a lumbar posterior osteotomy and a long fusion. Patients were divided into 3 groups based on postoperative sagittal vertical axis (SVA): neutral alignment (0 < SVA < 50 mm), anterior alignment (SVA > 50 mm), and posterior alignment (SVA < 0 mm). All patients underwent pre- and postoperative full-length sagittal spine radiography. Differences between groups were evaluated using ANOVA and &khgr;2 analysis. Results. Seventy-six patients were postoperatively classified in the anterior group: 59 in the neutral group and 48 in the posterior group. These groups were comparable preoperatively in terms of surgical status (revision vs. primary surgery) and regional alignment (lumbar lordosis and thoracic kyphosis). The patients with posterior alignment were younger and had a significantly lower pelvic incidence (53° vs. 62°), preoperative pelvic tilt (30 vs. 36°), SVA (94 vs. 185 mm) and cervical lordosis (16° vs. 25°) than patients in the anterior alignment group. No significant differences were found in terms surgical procedure. Patients in the posterior alignment group demonstrated a significantly greater change in SVA and pelvic tilt correction (P < 0.05) but with a lower gain in thoracic kyphosis (5 vs. 12°) and reduction of cervical lordosis (4° vs. 22°). Conclusion. A significantly lower pelvic incidence and lack of restoration of thoracic kyphosis may lead to sagittal overcorrection with a posterior alignment. Although the clinical significance of posterior malalignment is still unclear, this study showed a compensatory loss of cervical lordosis in these patients. Particular attention must be paid to preoperative planning before sagittal realignment procedures. Further study will be necessary to evaluate long-term clinical outcomes of these patients.

Optimal Treatment for Odontoid Fractures in the Elderly

Study Design. Clinically based systematic review. Objective. To define optimal clinical care for elderly patients with Type II and III odontoid fractures using a systematic review with expert opinion. Summary of Background Data. Numerous manuscripts have been written about treatment strategies of odontoid fractures in the elderly. However, these articles are of low quality and optimal treatment algorithms do not exist. Methods. Focused questions on the treatment of elderly patients with Type II and III odontoid fractures were refined by a panel of spine traumologists surgeons, consisting of fellowship trained neurologic and orthopedic surgeons. MeSH keywords were searched through MEDLINE, EMBASE, and the Cochrane Database of Systematic reviews, and pertinent abstracts and manuscripts obtained. The quality of literature was rated as high, moderate, low, or very low. Using the GRADE evidence-based review system, the proposed questions were answered using the literature review and expert opinion. These treatment recommendations were then rated as either strong or weak based on the quality of evidence and clinical expertise. Results. The literature searches revealed low and very low quality evidence with no prospective or randomized studies. The MEDLINE search engine returned 1759 articles, which were further limited to “all aged (65 and over),” human subjects and the English language. The subsequent search resulted in a return of 377 manuscripts. These abstracts where then reviewed in detail and 117 manuscripts were selected, which were obtained and supplemented with additional manuscripts to form an evidentiary table. Conclusion. Odontoid fractures have a significant morbidity in the elderly (>65 years) population. Type II fractures in this population are recommended to be treated operatively with a weak recommendation, and if treated nonoperatively using a hard collar immobilization device. Type III odontoid fractures in the elderly optimal treatment with a strong recommendation is immobilization in a hard collar.

Transoral laser microsurgery versus radiation therapy for early glottic cancer in Canada: Cost analysis

OBJECTIVE There is debate over whether radiation therapy or transoral laser microsurgery (TLM) is the superior treatment for early glottic cancer. Both offer similar cure rates and posttherapy quality of life. One factor that could decide the optimum therapy is cost. Several studies in Europe and the United States show that TLM is the most cost-effective treatment. The goal of this study was to conduct the first cost analysis in Canada on the treatment of early glottic cancer comparing radiation therapy and TLM. DESIGN AND METHODS The study was conducted retrospectively. TLM and radiation therapy were broken down into individual components, and then the price for each component was summed. SETTING The study was conducted at the Queen Elizabeth II Health Science Centre in Halifax, Nova Scotia. MAIN OUTCOME MEASURES The main outcome measure was total cost. RESULTS It was found that radiation therapy was approximately four times more expensive than TLM. CONCLUSIONS This study suggests that TLM should be the preferred treatment option for treating early glottic cancer in Canada as it is the most economical and has been shown in previous studies to be as effective as radiation therapy in both cure rates and quality of life.

Is preoperative ultrasonography accurate in measuring tumor thickness and predicting the incidence of cervical metastasis in oral cancer

The need for elective neck dissection in patients with early stage oral cancer is controversial. A preoperative predictor of the risk of subclinical nodal metastasis would be useful. Studies have shown a strong correlation between histological tumor depth and the risk of nodal metastasis. To determine if preoperative ultrasonography is an accurate measure of tumor depth in oral carcinoma. To assess if preoperatively measured tumor depth predicts an increased risk of subclinical metastatic neck disease and thus the need for elective neck dissection. Twenty one consecutive patients with biopsy proven squamous cell carcinoma of the tongue/floor of mouth were analyzed prospectively. Each patient received a preoperative ultrasonography to assess tumor depth which was compared to histological measures. Univariate analysis was used to correlate tumor thickness and T stage with neck metastasis. There was a significant correlation between the preoperative ultrasonography and histological measures of tumor depth (correlation coefficient 0.981, P<0.001). The overall rate of lymph node metastasis was 52%. The rate of metastasis was 33% in N0 necks. In the group with tumors<5mm in depth, the neck metastatic rate was 0%, as compared with 65% in the group 5mm. Using univariate analysis tumor depth and T stage were significant predictors of cervical metastasis (P=0.0351 and P=0.0300, respectively). Preoperative ultrasonography is an accurate measure of tumor depth in oral carcinoma. Tumor thickness is a significant predictor of nodal metastasis and elective neck dissection should be considered when this thickness is 5mm.

Segmental motion adjacent to an instrumented lumbar fusion: The effect of extension of fusion to the sacrum

Study Design. We present an in vitro biomechanical comparison of adjacent segment motion at the cranial segment (L3–L4) for an L4–L5 versus an L4–S1 fusion model using cadaveric lumbosacral spines. Objectives. The purpose is to determine the biomechanical effect on the unfused cranial segment of extending a short lumbar fusion to the sacrum versus stopping at L5. Summary of Background Data. Radiographic evidence of adjacent segment degeneration can occur as a late sequela in patients following lumbar and lumbosacral spinal fusions. It is believed that altered biomechanics adjacent to the fusion construct contribute to these degenerative changes. Little is known regarding changes in cranial adjacent segment mechanics resulting from inclusion of the sacrum compared to ending a fusion at L5. Methods. Seven human cadaveric lumbosacral spines were instrumented with pedicle screws at L4, L5, and S1. Rods were placed from L4–L5 and from L4–S1 to simulate the corresponding fusion models. A material testing system was used to apply load-controlled moments to the spines in flexion-extension, lateral bending, and axial rotation. Electromagnetic sensors were used to record 6 df motion across the L3–L4, L4–L5, and L5–S1 motion segments. Angular displacements were recorded and system stiffness was calculated for each spine and construct. A paired sample t test was used to determine significance of recorded differences. Results. Under flexion-extension loading, the angular displacement in the sagittal plane at L3–L4 for the L4–S1 model was 9.0° compared to 7.8° for the L4–L5 model (+15%; P = 0.002). Under lateral bending loading, L3–L4 motion in the coronal plane for the L4–S1 model was 12.8° and was 14.5° for the L4–L5 model (−12%; P = 0.002). In axial rotation testing, L3–L4 torsional motion for the L4–S1 model was equivalent to the L4–L5 model. Overall system stiffness increased for the L4–S1 model compared with the L4–L5 model. Conclusions. In this load-controlled model, extending fusion across L5–S1 did not consistently increase motion at L3–L4. While it may be difficult to translate this finding to a clinical setting, avoiding fusion to the sacrum in a lower lumbar fusion may not provide significant benefit from the standpoint of avoiding adjacent segment disease.

Radiographical and Implant-Related Complications in Adult Spinal Deformity Surgery: Incidence, Patient Risk Factors, and Impact on Health-Related Quality of Life

Study Design. A multicenter, prospective review of surgical patients with adult spine deformity. Objective. Assessment of the incidence, risk factor, and impact of radiographical and implant-related complications (RIC) on health-related quality of life measures. Summary of Background Data. This study provides assessment of the incidence of RIC in adult spinal deformity surgery and impact of these complications on need for reoperation. Risk factors for development of RIC are also assessed, as well as the impact of these complications on health-related quality of life (HRQOL) outcomes measures. Methods. A multicenter, prospective database of surgical patients with adult spinal deformity was reviewed. All patients with complete 2-year follow-up were included. HRQOL was measured using the Oswestry Disability Index, General Health Survey (36-Item Short Form Health Survey [SF-36]), and Scoliosis Research Society-22 (SRS-22r) at baseline, 6 weeks, 1 year, and 2 years postoperatively. Univariate testing was performed as appropriate. Multivariate logistic regression modeling was used to determine independent predictors of RIC. Multivariate repeated-measures mixed models were used to examine HRQOL, accounting for confounders. Results. A total of 245 patients met inclusion criteria. The incidence of RIC was 31.7% and 52.6% of those patients required reoperation. Rod breakage accounted for 47% of the implant-related complications, and proximal junctional kyphosis accounted for 54.5% of radiographical complications. Univariate analysis identified the following potential risk factors for RIC: weight, American Society of Anesthesiologists score, revision, stopping the fusion in the lower thoracic spine, worse SRS-Schwab classification modifiers (pelvic tilt++, pelvic incidence minus lumbar lordosis++, sagittal vertical axis++), higher T1 spinopelvic inclination, and higher T1 slope. Independent predictors of RIC as identified on multivariate logistic regression included American Society of Anesthesiologists (odds ratio: 1.75, P = 0.029) and sagittal vertical axis modifier ++ (odds ratio 3.43, P = 0.0001). The RIC and no RIC groups each experienced significant improvement over time, as measured on the Oswestry Disability Index (P = 0.0001), SF-36 (P = 0.0001), and SRS-22r (P = 0.0001). However, the rate of improvement over time was less for patients with RIC (SRS-22r P = 0.043, SF-36 P = 0.0001). Conclusion. This study identified that nearly one-third of patients undergoing adult spinal deformity surgery experienced a radiographical or implant-related complication, and that just more than one-half of these patients experiencing complication required a reoperation within 2 years of surgery. These complications significantly affected HRQOL measures. Baseline patient characteristics and parameters of the SRS-Schwab classification can be used to help identify those patients at greater risk. Level of Evidence: 3

Swallowing function in patients with base of tongue cancers treated with primary surgery and reconstructed with a modified radial forearm free flap.

OBJECTIVE To report swallowing outcomes and biomechanical properties of the base of the tongue (BOT) and the posterior pharyngeal wall (PPW) in patients who undergo surgical reconstruction with the beavertail modification of radial forearm free flap after primary resection of BOT cancer. DESIGN Prospective cohort study with a 1-year minimum follow-up performed between October 1, 2001, and August 31, 2005. SETTING Tertiary care facility. PATIENTS Patients diagnosed as having primary carcinoma of the BOT were treated with primary surgical resection and reconstruction followed by radiotherapy. Inclusion criteria were collection of videofluoroscopic swallowing study (VFSS) data before and 1 year after surgery. Forty-one patients were treated during a 5-year period, and 20 were included in the final analysis. INTERVENTIONS Reconstruction of BOT defects with the beavertail modification of radial forearm free flap followed by postoperative radiation. MAIN OUTCOME MEASURES Aspiration score, pharyngeal residue score, and biomechanical analysis of BOT and PPW mobility were performed using images from VFSSs. Both the BOT and PPW positions were measured from 2 static bony landmarks. RESULTS Of the 20 patients in the final analysis, 19 (95%) were able to swallow safely at 1 year. Mobility of the BOT after surgery was reduced in all postoperative VFSS data. Anteroposterior dimension or bulk of the BOT was preserved. No significant difference was found in PPW mobility. CONCLUSIONS The beavertail modification of the radial forearm free flap is a good reconstructive option after BOT cancer extirpation. The procedure preserves the bulk of the BOT after cancer treatment and maintains adequate BOT-PPW apposition. This allows structures such as the pharyngeal, oral, and suprahyoid musculature to contract and generate the necessary force to propel the food bolus through the oropharynx, resulting in a safe swallow.