Quantitative Discomanometry: Correlation of Intradiscal Pressure Values to Pain Reduction in Patients With Intervertebral Disc Herniation Treated With Percutaneous, Minimally Invasive, Image-Guided Techniques

Predictors of discogenic pain in magnetic resonance imaging: a retrospective study of provocative discography performed by posterolateral approach

Background

Provocative discography (PD) is a test that is useful in diagnosing discogenic pain (DP). In this study, to diagnose DP, we used a posterolateral approach of needle placement and followed pressure criteria laid down by the Spine Intervention Society. The aim was to identify the correlation between magnetic resonance imaging (MRI) findings (desiccation, high intensity zone and change in shape and size of the disc) and the results of PD.

Methods

Records of 50 patients who underwent PD for DP were analyzed. A total of 109 PDs were performed, with 54 suspect and 55 control discs. Alternate pain generators were ruled out.

Results

A total of 35 suspect discs were positive on PD. The mean disc pressure in the suspect disc was 31.9 ± 7.9 psi (range, 15-44). Of the 50 patients who underwent PD, 35 had positive MRI findings. A significant positive correlation was found only between disc desiccation and discography result (r = 0.6, P < 0.001). Logistic regression analysis revealed that only desiccation successfully predicted the result of discography (OR = 26.5, P < 0.001); a high intensity zone and a disc protrusion/extrusion had an OR 2.3 and 1.24, respectively. Disc desiccation of Pfirmann grade 3 or more had a sensitivity and specificity of 0.93 and 0.64 respectively in identifying painful discs; the positive likelihood ratio was 2.58 while the negative likelihood ratio was 0.11.

Conclusions

In patients with DP, disc desiccation is the most useful MRI feature that predicts a painful disc on PD.

Lasers in Spine Surgery

Laser spine surgery has been a focus of intense interest in the lay press and among patients. On the Internet, a host of purported benefits to laser surgery exists. Lasers have long been used in pain management procedures such as percutaneous diskectomy. However, a few published articles are available on lasers in conventional spine surgery. From our review of the literature, the purported advantages of lasers, such as reduced inflammation and degeneration, are not been supported by preclinical research. The available clinical studies do not show a notable advantage for laser surgery. Moreover, the low enrollment, nonblinded, retrospective studies that are available are heavily subject to bias. The documented advantages of laser spine surgery described in the research studies are not consistent with the public's impression of its purported benefits. Furthermore, laser-specific complications are present about which patients should be informed. On the basis of the current research, we conclude that lasers add distinct potential complications without any corresponding clinical benefit. Because of the public interest, we feel that this is an important topic for the general orthopaedic community.