Research & Publications

Eur Spine J. 2011 Jul;20(7):1095-105. Epub 2011 Feb 10.

Does lateral vertebral translation correspond to Cobb angle and relate in the same way to axial vertebral rotation and rib hump index? A radiographic analysis on idiopathic scoliosis.


Orthopedic Department, Guro Hospital, Korea University, Guro dong 80, Guro-gu, Seoul, Korea.


The deformity in idiopathic scoliosis (IS) is three dimensional in nature and effective correction involves all three planes. Even though the vertebral translation (VT) is an accepted element in the deformity along with vertebral rotation(VR) as reported by Asher and Cook (Spine (Phila Pa 1976) 20(12):1386-1391, 1995), Kotwicki et al. (Study Health Technol Inf 123:164-168, 2006) and Kotwicki and Napiontek (Pediatr Orthop 28(2):225-229, 2008), rib hump (rib hump index (RI)) and Cobb angle as reported by Aaro and Dahlborn (Spine (Phila Pa 1976) 6(6):567-572, 1981), it was assumed that VT was represented by adequately by Cobb angle and it was not analysed individually. We hypothesized that the Cobb angle and the VT measured in axial plane on CT scan and may not represent the same measurement and factors like coronal plane vertebral tilt,VR and vertebral deformation might affect them in different ways. Hence, VT should be considered as a separate variable and its relationship with VR, RI and Cobb angle should be investigated. Since the newer implants depend on curve translation and derotation for correction studying the role of VT and the relationships is important. VT, VR and RI were measured in CT scans of 75 patients with IS and correlated with Cobb angle. Regression analysis was used to identify the influence of the variables on each other. All the variables significantly correlated with one another but the correlation of Cobb and VT is not perfectly linear and it cannot be used to represent VT. VT influences RI much more than Cobb angle or VR. VT, therefore, merits further study treating it as an independent variable.

[PubMed – indexed for MEDLINE]

Free PMC Article


Spine (Phila Pa 1976). 2011 Sep 1;36(19):E1259-65.

Evaluation of the three-dimensional deformities in scoliosis surgery with computed tomography: efficacy and relationship with clinical outcomes.


Department of Orthopedics, Korea University Ansan Hospital, Seoul, South Korea.



Prospective radiological and clinical study with scoliosis patients.


To determine the pre- and postoperative differences in the three-dimensional (3D) parameters and relationships with the outcome in scoliosis surgery.


Despite a proven important role of the 3D deformities in scoliosis, it is warranted to confirm the efficacy of these measurements, which carry a cost burden and radiation hazard.


Fifty adolescent idiopathic scoliosis patients who underwent correction surgery were enrolled in this study. Pre- and postoperative whole spine radiographs and computed tomography were performed. The vertebral rotation (VR), rib hump index (RH), sternal shift (SS) on computed tomography were measured at the level of the apex in each patient. In addition, the patients described the SRS 30 (scoliosis research society 30) and ODI (owestry disability index) score. And, the differences in the parameter and the relationships between the radiological and clinical outcomes were analyzed.


There was significant decrease in the coronal curvature, RH, and SS after surgery (P < 0.0001). In addition, the VR decreased postoperatively but that was not significant (P = 0.236). There were significant relationships between the parameters in the coronal curvature, VR, RH, and SS, pre- and postoperatively (P < 0.05). However, regarding the pre- and postoperative differences, only the changes in the SS were related to changes in the coronal curvature (P = 0.006). In addition, there were significant relationships between the parameters and outcomes. The changes in ODI were related to changes in the coronal curvature, VR, RH, and SS (P < 0.0001, P = 0.039, P < 0.0001, P = 0.019, respectively). However, the changes in the SRS was only related to the changes in SS (P < 0.0001).


There were significant correlations between the VR, RH, and SS with the coronal curvature, pre- and postoperatively. In addition, there were significant correlations between the 3D deformities and outcomes. Computed tomography based measurements of 3D deformities can provide useful information in planning, and predicting the outcome of corrective surgery.

[PubMed – indexed for MEDLINE]

Arch Orthop Trauma Surg. 2011 Oct;131(10):1333-40. Epub 2011 Apr 13.

Comparative study of callus progression in limb lengthening with or without intramedullary nail with reference to the pixel value ratio and the Ru Li’s classification.


Department of Orthopaedic Surgery, Fuzhou General Hospital, Fuzhou 350025, Fujian, China.



Callus progression is a great concern during limb lengthening. In this study, we investigated the difference in callus progression between tibial lengthenings with and without intramedullary nail.


Seventy tibiae in 38 patients with an average age of 24 years were lengthened with Ilizarov external fixator and nail; 56 tibiae in 40 patients with an average age of 28.6 years were lengthened with the same Ilizarov external fixator but without nail. The callus progression was compared with reference to pixel value ratio (PVR) and Ru Li’s classification. Statistical analysis was performed to compare the variation trend of PVR and incidence of various callus pathways (particular patterns of callus progression as outlined in Ru Li’s classification) and shapes of each aspect of callus between the two groups.


The trend of PVR was not statistically different in posterior, lateral and medial aspects of the callus between the two groups, but averagely lower in the anterior aspect in the group without nail than that with nail. The group without nail presented less incidence of homogeneous pathway, greater incidence of heterogeneous pathway; also greater incidence of fusiform callus, less incidence of cylindrical callus.


It was concluded that with nail, the callus underwent a more favorable progression and even longer lengthening could be allowed.

[PubMed – indexed for MEDLINE]
J Bone Joint Surg Br. 2011 Jun;93(6):782-7.

Complications and outcome of tibial lengthening using the Ilizarov method with or without a supplementary intramedullary nail: a case-matched comparative study.


Department of Orthopaedic Surgery, Fuzhou General Hospital, No. 156 Second West Ring Road, Fuzhou, Fujian 350025, China.


We compared the complications and outcome of tibial lengthening using the Ilizarov method with and without the use of a supplementary intramedullary nail. In a retrospective case-matched series assembled from 176 patients with tibial lengthening, we matched 52 patients (26 pairs, group A with nail and group B without) according to the following criteria in order of importance: 1) difference in amount of lengthening (± 2 cm); 2) percentage difference in lengthening (± 5%); 3) difference in patient’s age (± seven years); 4) aetiology of the shortening, and 5) level of difficulty in obtaining the correction. The outcome was evaluated using the external fixator index, the healing index and an outcome score according to the criteria of Paley. It was found that some complications were specific to group A or B respectively, but others were common to both groups. The outcome was generally better in lengthenings with a nail, although there was a higher incidence of rectifiable equinus deformity in these patients.

[PubMed – indexed for MEDLINE]
J Orthop Sci. 2010 Nov;15(6):746-52. Epub 2010 Nov 30.

Comparison of bone age delay and recovery in Meyer dysplasia and Legg-Calvé-Perthes disease: a pilot study.


Department of Orthopaedic Surgery, Fuzhou General Hospital, Fuzhou, Fujian, China.



Meyer dysplasia (MD) is a rare disease but readily mistaken for Legg-Calvé-Perthes disease (LCPD). Although most published studies on MD have characterized and differentiated it from LCPD radiologically and clinically, differences with regard to bone age delay and recovery have not been sought. We deemed it necessary to distinguish bone age delay and recovery patterns between the two entities for better differentiation, prognostication, and parental advice.


Bone age delay and recovery of eight patients who were initially diagnosed with LCPD but were found to have MD were retrospectively reviewed and compared with those of age-matched patients with LCPD. Based on hand radiographs, the radius-ulna-short bones (RUSs) and carpal bone ages were determined using the Tanner and Whitehouse 3 (TW3) method. Minimum follow-up was 2 years (range 2-5 years). Differences in RUS and carpal bone ages and recovery patterns between the two entities were analyzed using trend lines in scatter plots.


The mean delay of RUS bone age was significantly less in MD (0.52 ± 0.87 years) than in LCPD (1.11 ± 0.99 years). However, the difference between the mean carpal bone age delay in MD (1.13 ± 1.28 years) and LCPD (1.47 ± 1.19 years) was not significant. Trend lines showed faster bone age recovery patterns in MD than in LCPD.


Bone age was delayed in both MD and LCPD but was less delayed in the former. RUS bone age showed more significant differences than carpal bone age when comparing the two entities and hence might be more useful for differentiating the two. Earlier bone age recovery patterns may be anticipated in patients with MD.

[PubMed – indexed for MEDLINE]

One thought on “Research & Publications

  1. Pingback: Welcome to the Spine & Scoliosis Clinic « Dr.Easwar's Spine Clinic

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.