Search Results

You are looking at 1 - 10 of 38 items for

  • Author or Editor: Thomas Mroz x
Clear All Modify Search
Full access

Yumeng Li, Daniel Lubelski, Kalil G. Abdullah, Thomas E. Mroz and Michael P. Steinmetz

Object

Bertolotti's syndrome consists of low-back pain caused by lumbosacral transitional vertebrae (LSTVs) and LSTV-associated biomechanical spinal changes. There is a lack of consensus regarding the cause, clinical significance, and treatment of this condition. The authors aim to characterize the clinical presentation of patients with Bertolotti's syndrome and describe a minimally invasive surgical treatment for this condition.

Methods

Seven patients who underwent minimally invasive paramedian tubular-based resection of the LSTV for Bertolotti's syndrome were identified over the course of 5 years. Diagnosis was based on patient history of chronic low-back pain, radiographic findings of LSTV, and pain relief on trigger-site injection with steroid and/or anesthetics. Electronic medical records were reviewed to identify demographics, operative data, and outcomes.

Results

All patients presented with severe, chronic low-back pain lasting an average of 8 years that was resistant to nonoperative care. At presentation, 6 (86%) of 7 patients experienced radicular pain that was ipsilateral to the LSTV. Radiographic evidence showed a presence of LSTV in all patients on the left (43%), right (29%), or bilaterally (29%). Degenerative disc changes at the L4–5 level immediately above the anomalous LSTV were observed in 6 of 7 (86%) patients; these changes were not seen at the level below the LSTV. Following pseudo-joint injection, all patients experienced temporary relief of their symptoms. All patients underwent a minimally invasive, paramedian tubular-based approach for resection of the LSTV. Three (43%) of 7 patients reported complete resolution of low-back pain, 2 (29%) of 7 patients had reduced low-back pain, and 2 patients (29%) experienced initial relief but return of low-back pain at 1 and 4 years postoperatively. Three (50%) of the 6 patients with radicular pain had complete relief of this symptom. The median follow-up time was 12 months. No intraoperative complication was reported. Two (29%) of 7 patients developed postoperative complications including one with a wound hematoma and another with new L-5 radiculopathy that resolved 2 years after surgery.

Conclusions

Diagnosis of Bertolotti's syndrome should be considered with adequate patient history, imaging studies, and diagnostic injections. A minimally invasive surgical approach for resection of the LSTV is presented here for symptomatic treatment of select patients with Bertolotti's syndrome whose conditions are refractory to conventional therapy and who have pain that can be attributed to the LSTV. Several short-term complications were noted with this procedure, but overall this procedure is effective for treating symptoms related to Bertolotti's syndrome.

Free access

Matthew J. Grosso, Roy Hwang, Thomas Mroz, Edward Benzel and Michael P. Steinmetz

Object

Reversal of the normal cervical spine curvature, as seen in cervical kyphosis, can lead to mechanical pain, neurological dysfunction, and functional disabilities. Surgical intervention is warranted in patients with sufficiently symptomatic deformities in an attempt to correct the deformed cervical spine. In theory, improved outcomes should accompany a greater degree of correction toward lordosis, although there are few data available to test this relationship. The purpose of this study is to determine if the degree of deformity correction correlates with improvement in neurological symptoms following surgery for cervical kyphotic deformity.

Methods

A retrospective review of 36 patients with myelopathic symptoms who underwent cervical deformity correction surgery between 2001 and 2009 was performed. Preoperative and postoperative radiographic findings related to the degree of kyphosis were collected and compared with functional outcome measures. The minimum follow-up time was 2 years.

Results

A significant relationship was observed between a greater degree of focal kyphosis correction and improved neurological outcomes according to the modified Japanese Orthopaedic Association (mJOA) score (r = −0.46, p = 0.032). For patients with severe neurological symptoms (mJOA score < 12) a trend toward improved outcomes with greater global kyphosis correction was observed (r = −0.56, p = 0.057). Patients with an mJOA score less than 16 who attained lordosis postoperatively had a significantly greater improvement in total mJOA score than patients who maintained a kyphotic position (achieved lordosis: 2.7 ± 2.0 vs maintained kyphosis: 1.1 ± 2.1, p = 0.044).

Conclusions

The authors' results suggest that the degree of correction of focal kyphosis deformity correlates with improved neurological outcomes. The authors also saw a positive relationship between attainment of global lordosis and improved mJOA scores. With consideration for the risks involved in correction surgery, this information can be used to help guide surgical strategy decision making.

Restricted access

Kalil G. Abdullah, Amy S. Nowacki, Michael P. Steinmetz, Jeffrey C. Wang and Thomas E. Mroz

Object

The C-7 lateral mass has been considered difficult to fit with instrumentation because of its unique anatomy. Of the methods that exist for placing lateral mass screws, none particularly accommodates this anatomical variation. The authors have related 12 distinct morphological measures of the C-7 lateral mass to the ability to place a lateral mass screw using the Magerl, Roy-Camille, and a modified Roy-Camille method.

Methods

Using CT scans, the authors performed virtual screw placement of lateral mass screws at the C-7 level in 25 male and 25 female patients. Complications recorded included foraminal and articular process violations, inability to achieve bony purchase, and inability to place a screw longer than 6 mm. Violations were monitored in the coronal, axial, and sagittal planes. The Roy-Camille technique was applied starting directly in the middle of the lateral mass, as defined by Pait's quadrants, with an axial angle of 15° lateral and a sagittal angle of 90°. The Magerl technique was performed by starting in the inferior portion of the top right square of Pait's quadrants and angling 25° laterally in the axial plane with a 45° cephalad angle in the sagittal plane. In a modified method, the starting point is similar to the Magerl technique in the top right square of Pait's quadrant and then angling 15° laterally in the axial plane. In the sagittal plane, a 90° angle is taken perpendicular to the dorsal portion of the lateral mass, as in the traditional Roy-Camille technique.

Results

Of all the morphological methods analyzed, only a combined measure of intrusion of the T-1 facet and the overall length of the C-7 lateral mass was statistically associated with screw placement, and only in the Roy-Camille technique. Use of the Magerl technique allowed screw placement in 28 patients; use of the Roy-Camille technique allowed placement in 24 patients; and use of the modified technique allowed placement in 46 patients. No screw placement by any method was possible in 4 patients.

Conclusions

There is only one distinct anatomical ratio that was shown to affect lateral mass screw placement at C-7. This ratio incorporates the overall length of the lateral mass and the amount of space occupied by the T-1 facet at C-7. Based on this virtual study, a modified Roy-Camille technique that utilizes a higher starting point may decrease the complication rate at C-7 by avoiding placement of the lateral mass screw into the T1 facet.

Free access

Sina Pourtaheri, Akshay Sharma, Jason Savage, Iain Kalfas, Thomas E. Mroz, Edward Benzel and Michael P. Steinmetz

OBJECTIVE

The flexed posture of the proximal (L1–3) or distal (L4–S1) lumbar spine increases the diameter of the spinal canal and neuroforamina and can relieve symptoms of neurogenic claudication. Distal lumbar flexion can result in pelvic retroversion; therefore, in cases of flexible sagittal imbalance, pelvic retroversion may be compensatory for lumbar stenosis and not solely compensatory for the sagittal imbalance as previously thought. The authors investigate underlying causes for pelvic retroversion in patients with flexible sagittal imbalance.

METHODS

One hundred thirty-eight patients with sagittal imbalance who underwent a total of 148 fusion procedures of the thoracolumbar spine were identified from a prospective clinical database. Radiographic parameters were obtained from images preoperatively, intraoperatively, and at 6-month and 2-year follow-up. A cohort of 24 patients with flexible sagittal imbalance was identified and individually matched with a control cohort of 23 patients with fixed deformities. Flexible deformities were defined as a 10° change in lumbar lordosis between weight-bearing and non–weight-bearing images. Pelvic retroversion was quantified as the ratio of pelvic tilt (PT) to pelvic incidence (PI).

RESULTS

The average difference between lumbar lordosis on supine MR images and standing radiographs was 15° in the flexible cohort. Sixty-eight percent of the patients in the flexible cohort were diagnosed preoperatively with lumbar stenosis compared with only 22% in the fixed sagittal imbalance cohort (p = 0.0032). There was no difference between the flexible and fixed cohorts with regard to C-2 sagittal vertical axis (SVA) (p = 0.95) or C-7 SVA (p = 0.43). When assessing for postural compensation by pelvic retroversion in the stenotic patients and nonstenotic patients, the PT/PI ratio was found to be significantly greater in the patients with stenosis (p = 0.019).

CONCLUSIONS

For flexible sagittal imbalance, preoperative attention should be given to the root cause of the sagittal misalignment, which could be compensation for lumbar stenosis. Pelvic retroversion can be compensatory for both the lumbar stenosis as well as for sagittal imbalance.

Restricted access

Kene T. Ugokwe, Iain H. Kalfas, Thomas E. Mroz and Michael P. Steinmetz

Object

Pseudarthrosis and construct failure following single-level anterior cervical discectomy, fusion, and plate placement (ACDFP) rarely occur. Routine postoperative anteroposterior and lateral radiographs may be an inconvenience to patients and expose them to additional and potentially unnecessary radiation. No standard exists to define when patients should obtain radiographs following an ACDFP. The authors hypothesize that routinely obtaining static anteroposterior and lateral radiographs in patients who recently underwent a single-level ACDFP without new axial neck pain or other neurological complaints or symptoms is unwarranted and does not alter the long-term treatment of the patient.

Methods

The authors retrospectively reviewed the charts and radiographs of patients who underwent a single-level ACDFP between January 1, 2000, and December 31, 2005. All patients underwent a single-level ACDFP and had routine cervical radiographs obtained at various intervals after surgery.

Results

Twenty-one patients underwent ACDFP at C5–6, 14 patients underwent surgery at C6–7, 11 patients at C4–5, and 7 patients at C3–4. None of the intraoperative radiographs demonstrated malposition of the graft or instrumentation. Based on subjective reporting by the patients, the vast majority (49 of 53) showed improvement in neck and arm pain, and/or neurological dysfunction following surgery. Overall, 5 patients (9%) demonstrated abnormalities on their postoperative radiographs. No patients were returned to the operating room as a result of postoperative radiographic findings. The sensitivity of plain radiographs in this patient series or the percentage of patients with new symptoms that had an abnormality related to the construct on plain radiography was 50%. The specificity of plain radiographs or the percentage of patients who were asymptomatic and had normal radiographs was 94%. The positive predictive value was 25%; that is, there was a 25% chance that patients with symptoms would have a construct abnormality on postoperative radiographs. The negative predictive value was 98%; that is, 98% of patients without symptoms will have normal radiographs.

Conclusions

Pseudarthrosis and construct failure following single-level ACDFP occur rarely, and patients with new symptoms following surgery are as likely to have normal radiographic findings as they are to have abnormalities identified on their postoperative plain radiographs. Routinely obtaining postoperative radiographs at regular intervals in asymptomatic patients following single-level ACDFP does not appear to be warranted.

Full access

Kalil G. Abdullah, Edward C. Benzel and Thomas E. Mroz

Comparative effectiveness research (CER) has impending significance for the field of spine surgery. This article outlines the rationale for comparative effectiveness research and reviews recommended priorities of spinal surgery emphasis. It also examines recent key studies of CER in the spine surgery literature and associated cost-effectiveness studies. It concludes with a discussion of the direction of CER in the spine surgery community.

Full access

Matthew D. Alvin, Daniel Lubelski, Edward C. Benzel and Thomas E. Mroz

Cervical spondylotic myelopathy (CSM) often can be surgically treated by either ventral or dorsal decompression and fusion. However, there is a lack of high-level evidence on the relative advantages and disadvantages for these treatments of CSM. The authors' goal was to provide a comprehensive review of the relative benefits of ventral versus dorsal fusion in terms of quality of life (QOL) outcomes, complications, and costs. They reviewed 7 studies on CSM published between 2003 and 2013 and summarized the findings for each category. Both procedures have been shown to lead to statistically significant improvement in clinical outcomes for patients. Ventral fusion surgery has been shown to yield better QOL outcomes than dorsal fusion surgery. Complication rates for ventral fusion surgery range from 11% to 13.6%, whereas those for dorsal fusion surgery range from 16.4% to 19%. Larger randomized controlled trials are needed, with particular emphasis on QOL and minimum clinically important differences.

Restricted access

Eric Z. Herring, Matthew R. Peck, Caroline E. Vonck, Gabriel A. Smith, Thomas E. Mroz and Michael P. Steinmetz

OBJECTIVE

Spine surgeons in the United States continue to be overwhelmed by an aging population, and patients are waiting weeks to months for appointments. With a finite number of clinic visits per surgeon, analysis of referral sources needs to be explored. In this study, the authors evaluated patient referrals and their yield for surgical volume at a tertiary care center.

METHODS

This is a retrospective study of new patient visits by the spine surgery group at the Cleveland Clinic Center for Spine Health from 2011 to 2016. Data on all new or consultation visits for 5 identified spinal surgeons at the Center for Spine Health were collected. Patients with an identifiable referral source and who were at least 18 years of age at initial visit were included in this study. Univariate analysis was used to identify demographic differences among referral groups, and then multivariate analysis was used to evaluate those referral groups as significant predictors of surgical yield.

RESULTS

After adjusting for demographic differences across all referrals, multivariate analysis identified physician referrals as more likely (OR 1.48, 95% CI 1.04–2.10, p = 0.0293) to yield a surgical case than self-referrals. General practitioner referrals (OR 0.5616, 95% CI 0.3809–0.8278, p = 0.0036) were identified as less likely to yield surgical cases than referrals from interventionalists (OR 1.5296, p = 0.058) or neurologists (OR 1.7498, 95% CI 1.0057–3.0446, p = 0.0477). Additionally, 2 demographic factors, including distance from home and age, were identified as predictors of surgery. Local patients (OR 1.21, 95% CI 1.13–1.29, p = 0.018) and those 65 years of age or older (OR 0.80, 95% CI 0.72–0.87, p = 0.0023) were both more likely to need surgery after establishing care with a spine surgeon.

CONCLUSIONS

In conclusion, referrals from general practitioners and self-referrals are important areas where focused triaging may be necessary. Further research into midlevel providers and nonsurgical spine provider’s role in these referrals for spine pathology is needed. Patients from outside of the state or younger than 65 years could benefit from pre-visit screening as well to optimize a surgeon’s clinic time use and streamline patient care.

Full access

Andrew T. Healy, Swetha J. Sundar, Raul J. Cardenas, Prasath Mageswaran, Edward C. Benzel, Thomas E. Mroz and Todd B. Francis

Object

Single-level anterior cervical discectomy and fusion (ACDF) is an established surgical treatment for cervical myelopathy. Within 10 years of undergoing ACDF, 19.2% of patients develop symptomatic adjacent-level degeneration. Performing ACDF adjacent to prior fusion requires exposure and removal of previously placed hardware, which may increase the risk of adverse outcomes. Zero-profile cervical implants combine an interbody spacer with an anterior plate into a single device that does not extend beyond the intervertebral disc space, potentially obviating the need to remove prior hardware. This study compared the biomechanical stability and adjacent-level range of motion (ROM) following placement of a zero-profile device (ZPD) adjacent to a single-level ACDF against a standard 2-level ACDF.

Methods

In this in vitro biomechanical cadaveric study, multidirectional flexibility testing was performed by a robotic spine system that simulates flexion-extension, lateral bending, and axial rotation by applying a continuous pure moment load. Testing conditions were as follows: 1) intact, 2) C5–6 ACDF, 3) C4–5 ZPD supraadjacent to simulated fusion at C5–6, and 4) 2-level ACDF (C4–6). The sequence of the latter 2 test conditions was randomized. An unconstrained pure moment of 1.5 Nm with a 40-N simulated head weight load was applied to the intact condition first in all 3 planes of motion and then using the hybrid test protocol, overall intact kinematics were replicated subsequently for each surgical test condition. Intersegmental rotations were measured optoelectronically. Mean segmental ROM for operated levels and adjacent levels was recorded and normalized to the intact condition and expressed as a percent change from intact. A repeated-measures ANOVA was used to analyze the ROM between test conditions with a 95% level of significance.

Results

No statistically significant differences in immediate construct stability were found between construct Patterns 3 and 4, in all planes of motion (p > 0.05). At the operated level, C4–5, the zero-profile construct showed greater decreases in axial rotation (–45% vs –36%) and lateral bending (–55% vs –38%), whereas the 2-level ACDF showed greater decreases in flexion-extension (–40% vs –34%). These differences were marginal and not statistically significant. Adjacent-level motion was nearly equivalent, with minor differences in flexion-extension.

Conclusions

When treating degeneration adjacent to a single-level ACDF, a zero-profile implant showed stabilizing potential at the operated level statistically similar to that of the standard revision with a 2-level plate. Revision for adjacent-level disease is common, and using a ZPD in this setting should be investigated clinically because it may be a faster, safer alternative.

Full access

Daniel Lubelski, Matthew D. Alvin, Sergiy Nesterenko, Swetha J. Sundar, Nicolas R. Thompson, Edward C. Benzel and Thomas E. Mroz

OBJECT

Studies comparing surgical treatments for cervical spondylotic myelopathy (CSM) are heterogeneous, using a variety of different quality of life (QOL) outcomes and myelopathy-specific measures. This study sought to evaluate the relationship of these measures to each other, and to better understand their use in evaluating patients with CSM.

METHODS

A retrospective study was performed in all patients with CSM who underwent either ventral or dorsal cervical spine surgery at a single tertiary-care institution between January 2008 and July 2013. Severity of myelopathy was assessed pre- and postoperatively using both the Nurick scale and the modified Japanese Orthopaedic Association (mJOA) classification of disability. Prospectively collected QOL outcomes data included Pain Disability Questionnaire (PDQ), Patient Health Questionnaire–9 (PHQ-9), and EQ-5D. Spearman rank correlations were calculated to assess the construct convergent validity for each pair of health status measures (HSMs). To assess each HSM’s ability to discriminate favorable EQ-5D index, we performed receiver operating characteristic (ROC) curve analysis and assessed the area under the curve (AUC).

RESULTS

A total of 119 patients were included. The PDQ total score had the highest correlation with EQ-5D index (Spearman’s rho = −0.82). Neither of the myelopathy scales (mJOA or Nurick) had strong correlations between themselves (0.41) or with the other QOL measures (absolute value range 0.13–0.49). In contrast, the QOL measures correlated relatively well with each other (absolute value range 0.68–0.97). For predicting favorable EQ-5D outcomes, PDQ total score had an AUC of 0.909. The AUCs were significantly greater for the QOL measures in comparison with the myelopathy measures (AUCs were 0.677 and 0.607 for mJOA and Nurick scale scores, respectively).

CONCLUSIONS

The authors found that all included measures of QOL and CSM-specific (mJOA or Nurick scale) measures were valid and responsive. The PDQ was the most predictive of positive QOL after surgery (as measured by the EQ-5D index) for patients with CSM. The substantially lower correlation between myelopathy and QOL outcomes, compared with the various QOL measures themselves, suggests that these questionnaires are measuring different aspects of the patient experience. Solely assessing the myelopathy or disease-specific signs and symptoms is likely insufficient to fully understand and appreciate clinical outcome in its totality. These questionnaire types should be used together to best evaluate patients pre- and postoperatively.