Can discoblock replace discography for identifying painful degenerated discs?

Objectives

The aim of the present study was to intra-individually compare provocative discography and discoblock (disc analgesia) of idiopathic degenerated discs (IDD) results to each other, to clinical parameters, and to MRI findings. By this the value of both diagnostic features should be critically reevaluated.

Methods

31 intervertebral IDD (Pfirrmann III°–IV°) of 26 patients were analyzed for surgery decision making by combined discoblock/discography procedure in an open MRI at 1 T. A correlation analysis was performed between the Dallas Discogram Scale, pain discrimination score (PDS: concordant/discordant/no pain), positive discoblock (Numerical Rating Scale [NRS] reduction by ≥3, 60 min after intervention), presence of Modic changes or high intensity zones (HIZ), patient sex and age, intervention level, injection pressure and discography endpoint analysis (pain/pressure/anatomic/volume).

Results

Concordant pain could be evoked in 35% of the IDDs whereas discoblock was positive in 64%. Patients’ age, sex, Dallas I, Dallas II, and Pfirrmann scores, as well as the presence of HIZ did not correlate to PDS or discoblock results. Discoblock correlated positively to concordant pain. Further positive correlation was found between PDS and intervention level/pressure, between discoblock and Modic changes/discography endpoint as well as between HIZ and discography endpoint.

Conclusions

We suggest discoblock to be an additional tool for surgery decision making in patients with IDD because it correlates to concordant pain evoked by provocative discography as well as to presence of Modic changes. Additionally, assessment of a release instead of provocation of pain can be of advantage.     

Periosteal cells compared with autologous cancellous bone in lumbar segmental fusion

OBJECT: Despite modern stabilization techniques and the use of autologous cancellous bone, bone consolidation does not occur in 10-15% of spinal fusion operations. There is also considerable donor site morbidity. Therefore, there is a definite need for material that has a larger measure of osteoinductivity, osteoconductivity, and osteogenic potential. METHODS: In this study, 24 patients with degenerative spinal disease underwent single-level circumferential lumbar fusion. The patients were randomly placed in 2 groups, each with different cage filling (Group 1, autologous iliac crest cancellous bone; Group 2, autologous periosteal cells in a fibrin/polyglactin-poly-p-dioxanone fleece). After 3, 6, 9, and 12 months, the patients underwent clinical (Oswestry Disability Index, patient satisfaction, willingness to undergo the operation again, visual analog scale for pain) and radiological (plain and flexion/extension radiographic and thin-layer computed tomography [CT]) examinations. RESULTS: The 6-month CT scans and 9-month radiographs obtained in Group 2 patients showed a significantly higher rate of fusion than those in Group 1 patients. Aside from this, there were no further significant differences. After 12 months, radiographic results showed a fusion rate of 80% in Group 1 and 90% in Group 2. No implant- or transplant-related complications were observed. CONCLUSIONS: The use of autologous periosteal cells on carrier material with osteoinductive and osteoconductive properties showed comparable results with autologous cancellous bone and better results with regard to consolidation at 6-9 months postoperatively. The shorter consolidation time, as well as lower donor site morbidity, justifies the clinical use and further development of this tissue-engineering strategy.     

Dynamic stabilization adjacent to single-level fusion: Part I. Biomechanical effects on lumbar spinal motion

Progression of superior adjacent segment degeneration (PASD) could possibly be avoided by dynamic stabilization of an initially degenerated adjacent segment (AS). The current study evaluates ex vivo the biomechanics of a circumferential fixation connected to posterior dynamic stabilization at the AS. 6 human cadaver spines (L2–S1) were stabilized stepwise through the following conditions for comparison: intact spine (ISP), single-level fixation L5–S1 (SLF), SLF + dynamic AS fixation L4–L5 (DFT), and two-level fixation L4–S1 (TLF). For each condition, the moments required to reach the range of motion (ROM) of the intact whole spine segment under ±10 Nm (WSP10) were compared for all major planes of motion within L2–S1. The ROM at segments L2/3, L3/4, and L4/5 when WSP10 was applied were also compared for each condition. The moments needed to maintain WSP10 increased with each stage of stabilization, from ISP to SLF to DFT to TLF (p < 0.001), in all planes of motion within L2–S1. The ROM increased in the same order at L3/4 (extension, flexion, and lateral bending) and L2/3 (all except right axial rotation, left lateral bending) during WSP10 application with 300 N axial preload (p < 0.005 in ANOVA). At L4/5, while applying WSP10, all planes of motion were affected by stepwise stabilization (p < 0.001): ROM increased from ISP to SLF and decreased from SLF to DFT to TLF (partially p < 0.05). The moments required to reach WSP10 increase dependent on the number of fixated levels and the fixation stiffness of the implants used. Additional fixation shifts motion to the superior segment, according to fixation stiffness. Therefore, dynamic instrumentation cannot be recommended if prevention of hyper-mobility in the adjacent levels is the main target.     

Dynamic stabilization adjacent to single-level fusion: Part II. No clinical benefit for asymptomatic, initially degenerated adjacent segments after 6 years follow-up

Progression of degeneration is often described in patients with initially degenerated segment adjacent to fusion (iASD) at the time of surgery. The aim of the present study was to compare dynamic fixation of a clinically asymptomatic iASD, with circumferential lumbar fusion alone. 60 patients with symptomatic degeneration of L5/S1 or L4/L5 (Modic ≥ 2°) and asymptomatic iASD (Modic = 1°, confirmed by discography) were divided into two groups. 30 patients were treated with circumferential single-level fusion (SLF). In dynamic fixation transition (DFT) patients, additional posterior dynamic fixation of iASD was performed. Preoperatively, at 12 months, and at a mean follow-up of 76.4 (60–91) months, radiological (MRI, X-ray) and clinical (ODI, VAS, satisfaction) evaluations assessed fusion, progression of adjacent segment degeneration (PASD), radiologically adverse events, functional outcome, and pain. At final follow-up, two non-fusions were observed in both groups. 6 SLF patients and 1 DFT patient presented a PASD. In two DFT patients, a PASD occurred in the segment superior to the dynamic fixation, and in one DFT patient, a fusion of the dynamically fixated segment was observed. 4 DFT patients presented radiological implant failure. While no differences in clinical scores were observed between groups, improvement from pre-operative conditions was significant (all p < 0.001). Clinical scores were equal in patients with PASD and/or radiologically adverse events. We do not recommend dynamically fixating the adjacent segment in patients with clinically asymptomatic iASD. The lower number of PASD with dynamic fixation was accompanied by a high number of implant failures and a shift of PASD to the superior segment.     

Application of a dynamic pedicle screw system (DYNESYS) for lumbar segmental degenerations - comparison of clinical and radiological results for different indications

AIM: Evaluation of the efficacy of a dynamic stabilizing system for different indications using medium-term clinical and radiological parameters. METHODS: Out of a total of 70 evaluated patients, 35 showed initial disc degeneration and disc herniation (group 1). In this group, additional nucleotomy was performed. Group 2 included 22 patients with initial osteochondrosis and facet joint osteoarthritis. 13 patients suffered from progressive segment degeneration or degenerative spondylolisthesis (group 3). Clinical evaluation was performed preoperatively, three months postoperatively and at follow-up (33 months). Examinations included subjective and objective measures using the Oswestry Index and VAS as well as radiographs and MRI. RESULTS: Oswestry Index and VAS improved significantly in groups 1 and 2 and remained improved until follow-up. Group 3 showed no significant changes. The evaluation of radiographs and MRI of groups 1 and 2 revealed no progression of the degeneration either at the operated segments or at the adjacent segments. In group 3, 9 cases of progressive degeneration of the operated segments and 3 cases of adjacent segment degeneration were found. Out of 5 implant-associated complications 4 were observed in group 3. CONCLUSION: Dynesys is able to compensate initial morphological changes and to prevent progression of segment degeneration. The system seems not to be indicated for treating marked deformities or if osseous decompression needs to be performed.     

Postoperative epidural anesthesia preserves lymphocyte, but not monocyte, immune function after major spine surgery

Extensive spine surgery is associated with postsurgical pain. Epidural pain therapy may reduce postoperative stress responses and thereby influence immune functions. In a randomized, controlled, double-blinded prospective trial, 54 patients received either conventional patient-controlled IV analgesia (PCIA; morphine 3 mg/15 min) or patient-controlled epidural analgesia (PCEA; 0.125% ropivacaine plus sufentanil 1 microg/mL at a base rate of 12 mL/h and bolus application of 5 mL/15 min). Circulating cytokines, C-reactive protein (CRP), cortisol, and cell-surface receptor expression of immune cells (cluster of differentiation [CD]14, human leukocyte antigen-DR, CD86, CD71, CD3, CD4, CD8, CD16, and CD19) were measured perioperatively to characterize immunological functions. PCEA, compared with PCIA, had no influence on altered levels of circulating cytokines (interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha, monocyte chemoattractant protein-1, and macrophage inhibitory factor) or indicators of the stress response (CRP and cortisol). Also, no significant difference was found in monocyte numbers or their human leukocyte antigen-DR, CD86, or CD71 expression. In contrast, the postoperative decrease in B lymphocytes and T-helper cells was significant in the PCEA group. Natural killer cells decreased significantly in patients receiving PCEA compared with PCIA. Therefore, postoperative epidural pain therapy has no influence on monocyte functions but reduces natural killer cells and preserves B-cell and T-helper cell populations. Epidural analgesia thus influences the specific rather than the innate immune system and potentially blunts the postsurgical lymphocyte depression, which is relevant for infectious resistance. IMPLICATIONS:Epidural analgesia affects the immune system. Postoperative epidural analgesia, compared with conventional IV opioid therapy, preserves lymphocyte rather than monocyte functions. An improvement of postoperative immune function by epidural analgesia therefore may improve postoperative resistance to infectious complications or to chronic pain states.