Kinematic analysis of dynamic lumbar motion in patients with lumbar segmental instability using digital videofluoroscopy

Dysfunctional segmental motion treated with dynamic stabilization in the lumbar spine

OBJECTIVE

To determine the suitability of the application of dynamic stabilization (DS) as a nonfusion technique to address dysfunctional segmental motion (DSM) in the lumbar spine.

METHODS

Over a 1-year period, 25 patients were treated with the same assessment and surgical protocol. Inclusion criteria were clinical presentation of DSM with or without stenosis. On preoperative and postoperative plain anteroposterior, lateral, and lateral flexion-extension radiographs, anterior and posterior disc height (DH); anteroposterior diameter of the disc; and global, segmental, apical segment, and below level lordotic angles (LAs) were measured.

RESULTS

The study included 9 women and 16 men with a mean age of 43.48 years ± 7.6. On average, patients had symptoms for 38.04 months ± 29.6, and mean follow-up was 12.36 months ± 3.46. The average height of anterior, posterior, and mean intervertebral discs increased significantly (P = 0.002, P = 0.003, and P < 0.0001). There were no significant differences between the preoperative and postoperative global, segmental, apical segment, and below segment LAs in flexion, extension, and neutral positions. At mid-term follow-up, no patients showed new signs of degeneration at the adjacent motion segment.

CONCLUSIONS

Overall, the limited radiologic data advocate DS as a nonfusion technique in the treatment of DSM in the lumbar spine. Long-term follow-up is essential, however, to investigate the long-term efficacy of DS in the surgical treatment of DSM.

Clinical tests to diagnose lumbar segmental instability: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVES

To evaluate the diagnostic accuracy of clinical tests used to diagnose patients with structural lumbar segmental instability (LSI).

BACKGROUND

Patients with structural LSI represent an important, identifiable subgrouping of individuals with low back pain. Numerous clinical tests have been proposed to diagnose structural LSI; however, data on the diagnostic accuracy of these tests have not yet been evaluated through a systematic review of the literature.

METHODS

A systematic review was conducted in 6 electronic databases for diagnostic accuracy studies, published between January 1950 and March 2010, that evaluated clinical tests against radiological diagnosis of structural LSI. The diagnostic accuracy of the clinical tests from the retrieved articles was independently evaluated, reviewed, and quality scored using the QUADAS tool.

RESULTS

Four articles and a total of 11 clinical tests used in the diagnosis of structural LSI met the study inclusion criteria. The majority of tests had high specificity but low sensitivity, with positive likelihood ratios ranging from very small to moderate. QUADAS scores ranged from 16 to 25 out of a possible 26. The passive lumbar extension test was the most accurate clinical test, with high sensitivity (84%), specificity (90%), and a positive likelihood ratio of 8.8 (95% CI: 4.5, 17.3), indicating that this clinical test may be useful in the differential diagnosis of structural LSI.

CONCLUSION

This systematic review found that the majority of clinical tests routinely employed to diagnose structural LSI demonstrated only limited ability to do so. The results do, however, indicate that the passive lumbar extension test may be useful in orthopaedic clinical practice to diagnose structural LSI. Additional research is required to further validate its use for diagnosing structural LSI in all populations of those with low back pain.

LEVEL OF EVIDENCE

Diagnosis, level 2a.