Reliability of cervical lordosis measurement techniques on long-cassette radiographs

PURPOSE

Lateral radiographs are commonly used to assess cervical sagittal alignment. Three assessment methods have been described and are commonly utilized in clinical practice. These methods are described for perfect lateral cervical radiographs, however in everyday practice radiograph quality varies. The aim of this study was to compare the reliability and reproducibility of 3 cervical lordosis (CL) measurement methods.

METHODS

Forty-four standing lateral radiographs were randomly chosen from a lateral long-cassette radiograph database. Measurements of CL were performed with: Cobb method C2-C7 (CM), C2-C7 posterior tangent method (PTM), sum of posterior tangent method for each segment (SPTM). Three independent orthopaedic surgeons measured CL using the three methods on 44 lateral radiographs. One researcher used the three methods to measured CL three times at 4-week time intervals. Agreement between the methods as well as their intra- and interobserver reliability were tested and quantified by intraclass correlation coefficient (ICC) and median error for a single measurement (SEM). ICC of 0.75 or more reflected an excellent agreement/reliability. The results were compared with repeated ANOVA test, with p < 0.05 considered as significant.

RESULTS

All methods revealed excellent intra- and interobserver reliability. Agreement (ICC, SEM) between three methods was (0.89°, 3.44°), between CM and SPTM was (0.82°, 4.42°), between CM and PTM was (0.80°, 4.80°) and between PTM and SPTM was (0.99°, 1.10°). Mean values CL for a CM, PTM, SPTM were 10.5° ± 13.9°, 17.5° ± 15.6° and 17.7° ± 15.9° (p < 0.0001), respectively. The significant difference was between CM vs PTM (p < 0.0001) and CM vs SPTM (p < 0.0001), but not between PTM vs SPTM (p > 0.05).

CONCLUSIONS

All three methods appeared to be highly reliable. Although, high agreement between all measurement methods was shown, we do not recommend using Cobb measurement method interchangeably with PTM or SPTM within a single study as this could lead to error, whereas, such a comparison between tangent methods can be considered.

Does cervical lordosis change after spinal manipulation for non-specific neck pain? A prospective cohort study

Background

The association between cervical lordosis (sagittal alignment) and neck pain is controversial. Further, it is unclear whether spinal manipulative therapy can change cervical lordosis. This study aimed to determine whether cervical lordosis changes after a course of spinal manipulation for non-specific neck pain.

Methods

Posterior tangents of C2 and C6 were drawn on the lateral cervical fluoroscopic images of 29 patients with subacute/chronic non-specific neck pain and 30 healthy volunteers matched for age and gender, recruited August 2011 to April 2013. The resultant angle was measured using ‘Image J’ digital geometric software. The intra-observer repeatability (measurement error and reliability) and intra-subject repeatability (minimum detectable change (MDC) over 4 weeks) were determined in healthy volunteers. A comparison of cervical lordosis was made between patients and healthy volunteers at baseline. Change in lordosis between baseline and 4-week follow-up was determined in patients receiving spinal manipulation.

Results

Intra-observer measurement error for cervical lordosis was acceptable (SEM 3.6°) and reliability was substantial ICC 0.98, 95 % CI 0.962–0991). The intra-subject MDC however, was large (13.5°). There was no significant difference between lordotic angles in patients and healthy volunteers (p = 0.16). The mean cervical lordotic increase over 4 weeks in patients was 2.1° (9.2) which was not significant (p = 0.12).

Conclusions

This study found no difference in cervical lordosis (sagittal alignment) between patients with mild non-specific neck pain and matched healthy volunteers. Furthermore, there was no significant change in cervical lordosis in patients after 4 weeks of cervical spinal manipulation.

Evaluating the head posture of dentists with no neck pain

INTRODUCTION

Dentistry is one of the professions that requires a high degree of concentration during the treatment of patients. There are many predisposing factors, affecting dentists when working on the patient's teeth, including neck flexion, arm abduction and inflexible postural positions, which may put them at the risk of developing musculoskeletal disorders related to the neck. Although dentists with long records of service show different levels of pain and discomfort in their necks, there is no evidence regarding whether younger dentists report neck pain before the onset of an abnormal condition in this region, including forward head posture (FHP). Discovering any alteration in the head posture of dentists might confirm one of the reasons for neck pain in this population.

MATERIALS

Forty one dentists with no neck pain and forty controls having jobs other than dentistry who had no risk factors related to head posture voluntarily participated in the present study. A standard method was used to measure the cervical curve in these two groups.

RESULTS

There was no significant difference between the mean values of cervical curve in dentists and the control group (p > 0.05). There was also no significant difference between cervical curve values in dentists working for either 5-8 years or 8-12 years (p > 0.05). The only significant difference was observed in mean cervical curve values of men and women in the dentist group (p < 0.05).

CONCLUSION

No alteration of cervical curve in the dentist group compared to controls might be due to absence of pain sensation in the dentists in the current study. In other words, this group might have not yet experienced sufficient change in head posture to experience significant pain in their neck region.

Late results of anterior cervical discectomy and fusion with interbody cages

STUDY DESIGN

Retrospective analysis.

PURPOSE

To evaluate the effectiveness of anterior cervical discectomy with fusion for degenerative cervical disc disease.

OVERVIEW OF LITERATURE

Anterior spinal surgery originated in the mid-1950s and graft for fusion was also employed. Currently anterior cervical microdiscectomy and fusion with an intervertebral cage is a widely accepted procedure for treatment of cervical disc hernia. Artificial grafts and cages for fusion are preferred because of their lower morbidity, reduced operating time and acceptable fusion rate.

METHODS

The study involved retrospective analysis and investigation of long-term results for 41 consecutive patients who had undergone anterior cervical discectomy and fusion with an intervertebral cage for cervical disc hernia. The angle of lordosis, segmental height and range of motion were evaluated preoperatively and postoperatively at 1 month and 2 years. The clinical outcome was assessed by the visual analog scale and Odom's criteria.

RESULTS

The angle of lordosis increased by 2.62° and the range of motion angle increased by 5.14° after the operation. The segmental height did not change. The visual analog scale and Odom's criteria scores decreased significantly after the operation.

CONCLUSIONS

Using a cage in anterior cervical discectomy prevents segmental collapse, so the segmental height and the angle of lordosis are preserved and newly-developed pain does not occur.