Association between patient-reported measures of psychological distress and patient satisfaction scores after spine surgery.

BACKGROUND: Patient satisfaction has become an important component of the delivery of health care in the United States. Previous studies have shown that patient satisfaction is influenced by patient-specific characteristics. The goal of this study was to determine whether psychological distress influences outpatient satisfaction scores following spine surgery. METHODS: We retrospectively reviewed the records from all outpatient clinical encounters at a single academic spine surgery center between February 2011 and January 2013. Any patient who completed both a patient satisfaction survey and a Distress and Risk Assessment Method (DRAM) questionnaire for the same clinical encounter was included in the study. Statistical analysis was performed to determine whether patient satisfaction scores were influenced by psychological distress. RESULTS: During the study period, 103 patients who met the inclusion criteria were identified. On the basis of their responses to the DRAM questionnaire, fifty-six were classified as normal (no evidence of distress), twenty-two as at risk, thirteen as distressed depressive, and twelve as distressed somatic. The mean overall patient satisfaction scores (and standard deviation) were 90.2 ± 10.9 in the normal group, 94.7 ± 8.2 in the at-risk group, 87.5 ± 16.2 in the distressed-depressive group, and 75.7 ± 22.4 in the distressed-somatic group (p = 0.003). The mean score for the patients' satisfaction with their provider was 94.2 ± 12.0 in the normal group, 94.2 ± 9.5 in the at-risk group, 90.6 ± 24.0 in the distressed-depressive group, and 74.9 ± 26.2 in the distressed-somatic group (p = 0.011). CONCLUSIONS: These results indicate a significant association between patient satisfaction and psychological distress as measured with the DRAM questionnaire. "Distressed" patients gave significantly lower scores for overall satisfaction and satisfaction with their provider compared with patients categorized as "normal." These results suggest that psychological factors may influence patients' perception of the medical care provided to them.

Improving the clinical evidence of bone graft substitute technology in lumbar spine surgery.

Bone graft substitutes have been used routinely for spine fusion for decades, yet clinical evidence establishing comparative data remains sparse. With recent scrutiny paid to the outcomes, complications, and costs associated with osteobiologics, a need to improve available data guiding efficacious use exists. We review the currently available clinical literature, studying the outcomes of various biologics in posterolateral lumbar spine fusion, and establish the need for a multicenter, independent osteobiologics registry.

Vertebral osteomyelitis secondary to Pseudallescheria boydii.

Because Pseudallescheria boydii vertebral osteomyelitis is rare and frequently resistant to available antifungal agents, the proper treatment of this lesion has not been defined. To better determine the best treatment of this lesion, the authors evaluated a case P. boydii vertebral osteomyelitis and reviewed the literature. A 48-year-old man had isolated thoracic vertebral osteomyelitis resulting from P. boydii and associated severe thoracic back pain and proximal lower extremity pain and weakness. Magnetic resonance imaging studies revealed continued collapse of the T6--T7 vertebrae despite previous posterior debridement and appropriate antifungal chemotherapy. On admission to the authors' institution, the patient underwent a right thoracotomy, anterior debridement with transthoracic T6--T7 corpectomies and strut grafting, followed by posterior fusion and stabilization with pedicle screws. After operation, the patient's pain, hyperalgesia, and lower extremity symptoms resolved. He was treated with a 12-month course of itraconazole. Imaging and laboratory studies show no evidence of recurrence. P. boydii vertebral osteomyelitis can have devastating neurologic sequelae if not treated properly. The frequent lack of response of this unusual fungal infection to systemic therapy requires frequent serial follow-up examinations. Patients with evidence of progression on imaging studies or neurologic findings should undergo early and aggressive surgical debridement.

Dynamic cervical plates: biomechanical evaluation of load sharing and stiffness.

STUDY DESIGN: An in vitro biomechanical study using a simulated cervical corpectomy model to compare the load-sharing properties and stiffnesses of two static and two dynamic cervical plates. OBJECTIVES: To evaluate the load-sharing properties of the instrumentation with a full-length graft and with 10% graft subsidence and to measure the stiffness of the instrumentation systems about the axes of flexion-extension, lateral bending, and axial torsion under these same conditions. SUMMARY OF BACKGROUND DATA: No published reports comparing conventional and dynamic cervical plates exist. METHODS: Six specimens of each of the four plate types were mounted on ultra-high molecular weight polyethylene-simulated vertebral bodies. A custom four-axis spine simulator applied pure flexion-extension, lateral bending, and axial torsion moments under a constant 50 N axial compressive load. Load sharing was calculated through a range of applied axial loads up to 120 N. The stiffness of each construct was calculated in response to +/-2.5 Nm moments about each axis of rotation with a full-length graft, a 10% shortened graft, and no graft. ANOVA and Fisher's post hoc test were used to determine statistical significance (alpha < or = 0.05). RESULTS: The two locked cervical plates (CSLP and Orion) and the ABC dynamic plate were similar in flexion-extension, lateral bending, and torsional stiffness. The DOC dynamic plate was consistently less stiff. The Orion plate load shared significantly less than the other three plates with a full graft. Both the ABC and the DOC plates were able to load share with a shortened graft, whereas the conventional plates were not. CONCLUSIONS: All plates tested effectively load share with a full-length graft, whereas the two dynamic cervical plates tested load share more effectively than the locked plates with simulated graft subsidence. The effect of dynamization on stiffness is dependent on plate design.

Segmental pedicle screw fixation or cross-links in multilevel lumbar constructs. a biomechanical analysis.

BACKGROUND CONTEXT: The placement of segmental pedicle screws and cross-links in short segment posterior pedicle screw constructs has been shown to increase the construct stiffness in some planes. To date, no studies have looked at the contributions of segmental pedicle screw and cross-link placement in longer constructs. PURPOSE: To evaluate the influence of segmental pedicle screw and/or cross-link placement on flexion/extension, lateral bending and axial torsion stiffness in two- and three-level posterior pedicle screw fixation constructs. STUDY DESIGN/SETTING: An in vitro biomechanical analysis of two- and three-level posterior pedicle screw constructs with and without segmental fixation and/or cross-links was performed using calf lumbar spines. Stiffness of the constructs was compared. METHODS: Six calf lumbar specimens were used to test stiffness in one-, two- and three-level posterior pedicle screw fixation constructs in 12 configurations. A custom-made, four-axis spine simulator applied pure cyclical (+/-5 Nm) flexion/extension, lateral bending and axial torsion moments at 0.1 Hz under a constant 50-N axial compressive load. The stiffness of each construct was calculated about each axis of rotation. Data were analyzed using nonparametric techniques with statistical significance determined at alpha less than .05. RESULTS: The stiffness of the instrumented spines were significantly greater than the noninstrumented intact spines in all loading conditions for one-, two- and three-level constructs. There were no significant changes in flexion/extension stiffness with the addition of either the cross-links or the segmental pedicle screws. In lateral bending, the addition of segmental pedicle screws significantly increased the stiffness in the two- and three-level constructs. The addition of two cross-links increased lateral bending stiffness in the longer three-level constructs, with little change in the two-level constructs. In axial torsion, the progressive addition of cross-links showed a tendency toward increased stiffness in both the two- and three-level constructs. Segmental pedicle screws further increased torsional stiffness of the longer, three-level constructs. CONCLUSIONS: As the use of segmental spinal instrumentation progresses from one to two and three levels, the contribution of cross-links and segmental pedicle screws to the overall construct stiffness increases.

Anterior instrumentation of the thoracolumbar spine. A biomechanical comparison.

STUDY DESIGN: To evaluate the fatigue strength and stiffness of four anterior thoracolumbar fixation devices using a corpectomy model without load-sharing bone graft to test the devices under the worst case scenario of instability. OBJECTIVES: To gain a more thorough understanding of the biomechanical qualities of anterior fixation devices to improve clinical application and design. SUMMARY OF BACKGROUND DATA: For many surgeons, the anterior approach has become the treatment of choice for patients with compression of the spinal cord, whether it is caused by trauma, tumor, or infection. When stabilization is needed, anterior fixation devices have been advocated for many years to avoid the additional approach required for posterior fixation. Many of these devices, however, have an unacceptably high rate of hardware failure. Recently, several new devices for anterior fixation have been marketed with purported advantages in fatigue life and ease of use. METHODS: Four implants, the Synthes Anterior Thoracolumbar Locking Plate, the Kaneda device, a Texas Scottish Rite Hospital anterior construct, and the Z-Plate were attached to vertebral models and tested for stiffness in multiple planes on a modified Materials Testing System machine. They then were fatigued to failure on an Instron testing machine. RESULTS: The Anterior Thoracolumbar Locking Plate was the stiffest in axial compression, lateral flexion, and torsion. The Texas Scottish Rite Hospital anterior construct was the least stiff in flexion-extension, with no significant differences in the stiffness of the anterior thoracolumbar locking plate, that of the Kaneda device, and that of the Z-Plate. Fatigue life exceeded 80,000 cycles for the anterior thoracolumbar locking plate and averaged 26,472 cycles for the Z-Plate, 6915 cycles for the Teas Scottish Rite Hospital construct, and 4419 cycles for the Kaneda device. CONCLUSIONS: The significantly greater fatigue life of the Anterior Thoracolumbar Locking Plate and the Z-Plate may predict a lower incidence of hardware failure than with previous anterior devices. This has been confirmed in preliminary clinical studies with the Z-Plate. Further clinical studies are needed to show if these lower failure rates will continue over a long-term period.

Posterior lumbar interbody fusion. A biomechanical comparison, including a new threaded cage.

STUDY DESIGN: In vitro biomechanical testing was performed on eight lumbar calf spines. OBJECTIVES: To compare the initial stiffness of a standard method of posterior lumbar interbody fusion using structural autograft with the same procedure using additional posterior instrumentation. These constructs also were compared to a new titanium implant. SUMMARY OF BACKGROUND DATA: Posterior lumbar interbody fusion is gaining wide acceptance for the treatment of segmental spinal instability, spondylolisthesis, and discogenic pain. Many methods have been described, including use of autograft or allograft bone, in either structural or nonstructural form, with or without additional fixation. A new threaded titanium interbody implant has been designed to increase initial stability while allowing bony ingrowth for fusion. METHODS: Eight lumbar calf spines were subjected to axial compression, sagittal moments (flexion-extension), and axial torque while displacement was measured. Stiffness was calculated from the load displacement curves for each construct under each load pattern. RESULTS: The posterior lumbar interbody fusion by bone graft alone was the least stiff construct of all modes tested. In two of eight specimens the bone graft dislodged posteriorly into the canal during torsional testing. The titanium interbody implant was similar in stiffness to the bone graft posterior lumbar interbody fusion with posterior instrumentation group in all three modes. They were both significantly stiffer than the normal spine, the destabilized spine, and the posterior lumbar interbody fusion by bone graft alone (P < 0.05). CONCLUSIONS: In this model, the posterior lumbar interbody fusion with bone graft alone had less initial stiffness than that of the intact spine. The addition of posterior instrumentation or interbody implants can increase initial stiffness significantly.

Case report 803: Gorham's disease (Gorham-Stout syndrome) of scapula.

In summary, a 36-year-old man presented with pain and limited motion in the shoulder. Clinical examination revealed obliteration of normal scapular landmarks in the conspicuous absence of any palpable soft tissue mass. Roentgenograms showed progressive osteolysis of the scapula. Biopsy confirmed the diagnosis of Gorham's disease. MRI played a key role in defining the extent of disease involvement and in displaying the distinct soft tissue anatomy. These MRI features are to our knowledge previously undescribed.

Modified Smith-Robinson procedure for anterior cervical discectomy and fusion.

Fifty-one consecutive patients with cervical radiculopathy or spondylosis were treated with single or multilevel anterior discectomy and fusion using a modified Smith-Robinson procedure. There were 33 single-level fusions, 16 two-level fusions, and 2 three-level fusions. The three modifications included: 1) the endplates at the fusion level were completely removed with a high-speed bur to exposed bleeding cancellous bone in parallel planes; 2) the Caspar distractor (Aesculap, Burlingame, CA) was used to increase distraction and improve visualization; 3) the tricortical autologous iliac crest bone graft was placed in reverse position, that is, with the cortical cross-section facing posteriorly, creating a stabilizing strut in the middle column. With an average follow-up of 1 year, the fusion rate was 94% (67 of 71 levels). The single-level fusion rate was 97%, the two-level fusion rate was 94%, and the three-level fusion rate was 83%. Of the four nonunions, only two were symptomatic. Results by clinical examination revealed 36 (71%) excellent, 11 (21%) good, 3 (6%) satisfactory, and 1 (2%) poor outcomes. There were no significant disc collapses or extrusions. One patient had an increase in kyphotic deformity of > 5 degrees, none with > 10 degrees kyphosis. There were no wound infections or neurologic complications. The modified Smith-Robinson procedure for anterior cervical discectomy and fusion has led to the successful treatment of cervical radiculopathy and spondylosis with improved results and few complications.

Effects of ankle-foot orthoses on the gait of children.

Gait analysis was performed on five normal children walking barefoot with bilateral double-upright ankle-foot orthoses (AFOs) and with plastic AFOs. When orthoses were worn, walking speed and cadence were reduced and quadriceps EMG timing was prolonged. Changes in lower extremity motions and torques were observed. The metal-and-leather AFOs impaired normal walking, more than the plastic orthoses. This study provides baseline information for evaluation of new orthotic designs and materials for children. In clinical practice, this information may be useful in selection of orthotic materials for some patients.