A summary of medical ph.d dissertation: Research on clinical features, x-ray image and evaluation on the results of adolescent idiopathic scoliosis correction surgery

The subject: “Research on clinical features, x-ray image and evaluation on the results of adolescent idiopathic scoliosis correction surgery”with 2 objectives: 1. Survey the clinical features and x-ray images of unknowncause scoliosis of the adolescence age as a basis for surgery designation. 2. Evaluate the results of scoliosis surgery by direct rotation of the vertebral body.

MINISTRY OF EDUCATION AND TRAINING - MINISTRY OF DEFENSE CLINICAL MEDICINE SCIENCE RESEARCH INSTITUTE

108 MILITARY CENTRAL HOSPITAL

PHAM TRONG THOAN

RESEARCH ON CLINICAL FEATURES, X-RAY IMAGE AND EVALUATION ON THE RESULTS OF ADOLESCENT IDIOPATHIC SCOLISIS CORRECTION SURGERY

Major: Trauma Orthopedic Code: 62720129

A SUMMARY OF MEDICAL PH.D DISSERTATION

HANOI, 2019

WORKS COMPLETED AT:

CLINICAL MEDICINE SCIENCE RESEARCH INSTITUTE - 108

MILITARY CENTRAL HOSPITAL

Supervisors:

1 Ass Prof Pham Hoa Binh

2 Ph.D Phan Trong Hau

BACKGROUND

Adolescent idiopathic scoliosis accounts for the highest proportion (2-4% of adolescents) The characteristics of the disease are physical body deformities that cause the spine to curl to one side and rotate the vertebrae on three planes Spinal deformities occur on a normal healthy body, if severe and untreated, such deformities may lead to complications, sequelae: backache, cardiopulmonary function impairment, physical body deformities, psychological insecurity, patients lose confidence when they integrate into the community Scoliosis appears silently and become severe in puberty, continues to change until adulthood The complications and sequelae have a very different impact and effect for each individual Scoliosis correction surgery is often very difficult and complex with many risks, future results may change without meeting the expectations of patients and their families Decision on surgery, selection on surgical techniques must be carefully considered and accurately planned based on a process

of monitoring, detailed assessment of clinical and x-ray characteristics

as well as the evolution of curves, rate of growing and synthesizing prognostic factors

Until now in Vietnamese medical literature, there has not been a study of in-depth analysis of reference data on Vietnamese people such as clinical features and x-ray images to serve as basis for the designation and selection of the most appropriate surgical techniques for each case of scoliosis in adolescents, no work has reported the application of direct rotation of vertebral body in scoliosis correction surgery We study the

subject: “Research on clinical features, x-ray image and evaluation

on the results of adolescent idiopathic scoliosis correction surgery”with 2 objectives:

1 Survey the clinical features and x-ray images of cause scoliosis of the adolescence age as a basis for surgery designation

unknown-2 Evaluate the results of scoliosis surgery by direct rotation of the vertebral body

CHAPTER 1 OVERVIEW 1.1 Outline of idiopathic scoliosis

1.1.1 Functional anatomy characteristics of the thoracic and lumbar spine

The thoracic and lumbar spines are spinal segments from T1 to L5 with two opposite physiological curves With lumbar spine, spinal functional unit consists of two vertebral bodies, intervertebral disc connecting the two vertebral bodies and the soft parts that links them Biomechanical studies assessing the role of components in lumbar spinal function units by Abumi showed that supraspinous ligament and interspinous ligament did not affect the firmness and movement amplitude of the spinal unit However, the joints and intervertebral disc are important and directly affect the instability of the lumbar spinal movement unit For the thoracic spine surrounded by the rib cage, sternum and back muscles, the anatomical structure and the biomechanical role of the relevant factors have many differences from the lumbar spine The thoracic spine is connected to the rib through costa joints, including the transverse costal joint and articulation of head of rib (or cost central articulations) Costa joints are surrounded

by ligaments such as transverse ligaments, wing ligaments and joint ligaments Takeuchi's research on experiment showed that the costa joint and the intervertebral disc are important components in the thoracic spinal function unit

internal-1.1.2 Clinical features of idiopathic scoliosis

1.1.2.1 Objective symptoms

Objective symptoms of scoliosis patients depend on the location and magnitude of the curve The patient's age at onset is significant in assessing the flexibility of the spine and predicting the risk of progression of the curve Changing gait of scoliosis patients can be observed when the scoliosis angle is large or causing nerve damage For scoliosis in the chest if the top vertebrae rotate much, it will cause imbalance of the rib cage - convex side and concave side, the clinical examination may show that the posterior rib cage - convex side is higher than the concave side due to the protrusion of the ribs Scoliosis patients may have two disproportionate shoulders, the protrusion of the left or right shoulder is an important factor for determining the screw position and fixation for each type of curve

1.2.The role of X-ray imaging and CT scanning in scoliosis assessment

1.2.1 The role of X-ray imaging in scoliosis assessment

To comprehensively assess scoliosis patients, the x-ray image of the entire spine plays an important role On animated X-ray films, it can

be assessed the flexibility of each spinal curve, the film tilting into one side is important in assessing curves, the basis for determining the extent of bone welding and has an important role to for the high thoracic curves and lumbar thorax Films with deviated peak padding, neck pulls or deviated peak push-press contribute to analyzing and evaluating spinal flexibility, predicting correction ability, determining bone welding position None of the films has superior superiority in assessing factors related to location diagnosis, flexibility and determination of bone fixation location, so it is necessary to take enough films to serve as the basis for analyzing and evaluating the preparation before surgery

1.3 Surgical treatment for scoliosis patients

1.3.1.Scope, screwing position for curves according to Lenke's classification

Lenke's classification system is designed for doctors to plan surgery based on the classification of curves The principle is that the main curves and the real curves need to be fixed to the bone, the offset curve can adjust itself after surgery

1.3.1.1 For the main thoracic curve, Lenke type 1

Lenke’s type 1A curve at the position LIV may stop at the intermediate vertebrae, the position UIV depends on the shoulder balance and characteristics of the high thoracic curve When selecting the position LIV higher than the intermediate vertebrae, the risk of losing offset is very likely to occur

1.3.2 scoliosis surgery by direct rotation of the vertebral body

A scoliosis correction system when applied in surgery needs to achieve factors such as creating the strongest correction force, max.correction of the spinal deformities with the number of vertebrae bolted and bone-welded is as few as possible

Principles and techniques of direct rotation of the vertebral body have been studied, introduced and applied in clinical practice

When implementing vertical rod derotation technique, scoliosis correction has two impact force vectors The first is the vector of

vertical rod rotation force; this force element directly affects the back and side of the vertebrae This force corrects deformities on the plane of the forehead plane and the vertical plane but has no impact element on the horizontal plane At the same time, when rotating, the vertical rod itself also rotates around its axis 90 degrees which is the next force vector This can affect the vertebral body rotation of scoliosis patients For scoliosis patients with large Cobb angle and without the flexibility of the curve, there is a large friction force between the vertical rod and the pedicle screw during the vertical rod rotation In that case the rotating force of the vertical rod will increase the rotation degree of the curve deformity If there is no friction between the screw and the vertical rod, the screw will slide on the vertical rod In this situation, the rotational deformity correction depends on the angle of the pedicle screw and the vectors of the vertical rod rotation force Clinically, the effect of rotational deformity correction of vertical rod rotation technique is negligible because it always exists a large friction between the vertical rod and the screw during the vertical rod rotation The concept of direct vertebral rotation is to correct the deformity

of the vertebral body by a direct force opposite the back of the curve deformity The pedicle screw is taken from the back of the vertebral body through the peduncle and to the front of the vertebral body; with this position of the pedicle screw, it can transmit force into the deformed vertebral body and perform the rotational correction Fixed tools such as steel wires, hooks do not perform this transmission force because the means only lie behind the vertebra The direct rotation of the vertebral body is carried out on the opposite side of the rotational deformity, the opposite direct rotation force can correct the rotational deformity on the horizontal plane and correct the deformity in three-dimensional space

Figure 1.1 The principle of direct rotation of the vertebral body

Directvertebral rotation Slide between screw and vertical rod

CHAPTER 2 SUBJECTS AND METHODS OF RESEARCH

2.1 Research subjects

Subjects include 40 adolescent idiopathic scoliosis patients who are undergoing surgical treatment with Lenke's scoliosis correction method by a system of pedicle screws via peduncle in the Faculty of Trauma Orthopedic Spine, 108 Military Central Hospital from August

2009 to July 2016

2.1.1.Criteria for selecting patients

(According to the recommendation of World Scoliosis Society) -Idiopathic scoliosis patient

- Cobb angle > 40 degrees

- Adolescence age

- Eligible for anesthesia, resuscitation

- Records of sufficient data and follow-up time

2.2.3.Clinical scoliosis research criteria

- Iliac crest balance

- Shoulder balance

- Bodybalance

- Balance the rib cage and bone…

2.2.4.Research criteria on x-ray film

- Difference of spine rib angle

- Balance the collarbone…

2.2.5 Surgical method

2.2.5.1 Pre-surgerical preparation

Determine the tactic of screwing according to Lenke as following:

Type 1: Main thoracic curve

- The vertebrae position of the bottom screw is the intermediate vertebra for the 1A, 1B curve The vertebrae position of the top screw

of the curve: patients with the right shoulder higher than the left shoulder will put the screw to T4, patients with the two shoulders

balancing before the surgery will put the screw on T3, and patients with the left shoulder higher than the right shoulder will put the screw to T2

- Curve type 1C: the position of the bottom screw extends to the

lumbar spine 2 levels under intermediate vertebra

Type 2: Double curve of the thoracic spine

- Determine the vertebra to put the top screw on the top: if the left shoulder is higher, put the screw up to T2; if the right shoulder is higher, put the screw T3; if two shoulders are balanced, put the screw

on T4 The vertebrae position to be put the bottom screw is as type 1

2.2.7.3 Criteria for evaluating treatment results

Evaluating the treatment results is based on the following criteria

- The effectiveness of correcting scoliosis according to Harrington

- Evaluate according to SRS-24 criteria

- Evaluate complications during and after surgery

2.2.8 Data processing methods

Use the software SPSS 22.0 for medical statistics

- Results of qualitative variables and quantitative variables with subgroups are presented in the form of frequency and percentage

- Results of quantitative variables are presented as: average +/- standard deviation or the median (smallest-largest)

- To compare the relationship between qualitative variables, percentages or quantitative variables with subgroups, we use Chi-Squared tests

- To compare the relationship among quantitative variables with normal distribution and qualitative variables with two values, we use the T test for two independent groups

- The difference is considered statistically significant when the value of

p is <0.05

CHAPTER 3 RESEARCH RESULTS

3.1.Clinical features of the research patient group

Table 3.1.Classification by patient’s age

The oldest patient is 21 years old and the youngest is 8 years old,

of which the age of 10-18 years accounts for 85%, there are 4 patients older than 18 years old These patients were examined and found out at adolescence age when monitoring periodically Due to objective and subjective conditions of patients, when she was older than 18 years, she could afford to carry out a surgery An 8-year-old patient underwent surgery because at the time of the examination, the patient had iliac crest ossification developed to Risser III, the patient had menstruation, deformity of the lumbar misalignment greater than 4.8 cm, large iliac crest imbalance, large rib cage deformity, comparing Cobb angles after one year, we see a rapid progression (Cobb angle after one year of follow-up from 25 degrees to 68 degrees) Considering the above factors of patients, we decided to make surgical intervention

Figure 3.1 Picture of an 8-year-old patient before surgery, the arrow pointing her body curve 4.8cm to the side and rib cage difference of 16

degrees

3.1.2 Clinical features

Table 3.3 Clinical features of surgical patients group

Bilateral iliac crest balance 0.09 ± 0.1 cm

Clinically, the scoliosis patient group indicated for surgery has an imbalance in the body, and the iliac crest and rib cage Of which, for the deformity of the rib cage, the difference of both sides is 13.25 degrees, the body imbalance of 4.63 cm, the average shoulder imbalance of 0.93 cm, the patient had a physical change from the shoulder to the waist and the whole body

3.2 X-ray image features of research patient group

Table 3.6.Features on the straight X-ray film

Indicators in X-ray image Average value

Misalignment of top vertebrae of thoracic spine 5.33 ± 2.44 cm Misalignment of top vertebrae of lumbar spine 1.48 ± 1.86 cm

degree Bilateral collar bone difference 5.75 ± 4.26 degree Bilateral collar bone difference of rib cage 8.31 ± 6.44 degree The deflection angle of the disc under the position

fixed with horizontal plane

15.48 ± 6.72 degree

Scoliosis patient group indicated for surgery has with many deformities on straight x-ray film, bilateral clavicle imbalance, imbalance of spinal ribs, rib cage in which deformity of spinal rib difference is up to 25.4 degrees, Misalignment of top vertebrae of thoracic spine of 5.33cm

3.2.2 Characteristics on inclined x-ray film.

Table 3.9 Characteristics on inclined x-ray film

Indicators in inclined X-ray image Average value

Spinal axis difference via C7 1.16 ± 0.16 cm

Kyphotic angle of thoracic spine T5-T12 19.45 ± 10.6 degree

Kyphotic angle of lumbar spine T10-L2 5.68 ± 5.87 degree Lumbosacral curvature (L1S1) - angle 35.95 ± 11.42

degree Total number of patient N=40

The patient had an average kyphotic angle of the thoracic spine of 19.45 degrees, the average kyphotic angle transition area of 5.68 degrees The kyphotic angle deformities T5-T12 are in normal values (from 10 degrees to 40 degrees)

3.3 Treatment results

3.3.1 Near results of treatment after surgery

A total of 40 postoperative patients had a scar healing in the first period, no infection Two patients had complications immediately after surgery, of which one patient had a hemothorax, one patient put the screw in wrong position which made through the left peduncleT7 into the spinal canal and showed signs of spinal marrow injury

3.3.1.1 Clinically near treatment results

Table 3.16 Results of clinical spinal correction immediately after

surgery

Shoulder balance 0.93 ± 0.64 cm 0.28 ± 0.17 cm P<0.001

Body balance 4.63 ± 1.37 cm 0.95 ±0.36 cm P<0.001 Iliac crest balance 0.09± 0.1 cm 0.09 ± 0.1 cm P>0.05 Rib cage balance 13.25± 5.74

degree

4.07 ±3.29 degree

P<0.001

Total number of

patient

40 Patients had shoulder imbalance before surgery of 0.93 cm on average The effect of correcting and restoring the patient's shoulder balance reached an average of 0.28cm The level of body balance recovery over the patient's waist is significantly improved compared to pre-surgery The body imbalance over the patient's waist before surgery

is 4.63 cm on average The body balance restored after surgery was 0.95 cm that was statistically significant with p <0.001

Changing the patient’s physique through indicators such as the shoulder balance, body balance over the waist and rib cage has a clear difference from pre-surgery

3.3.1.2 Height change after surgery

Table 3.17 Height change immediately after surgery (n = 40

patients)(unit: cm)

Patient’s height Average Deflection P value

Height before surgery 154.50 8.269

the average height increased by 5.425 cm

3.3.1.3 Kết quả điều trị gần trên hình ảnh x-quang

Table 3.18 Results of the spinal correction on straight x-ray image

right after surgery

Misalignment of top vertebrae of

thoracic spine

5.33 ± 2.44

cm 1.2 ± 0.85 cm p<0.001 Misalignment of top vertebrae of

Bilateral collar bone difference 5.75 ± 4.26

degree

2.9 ± 2.02 degree p<0.001 Bilateral collar bone difference of

rib cage

8.31 ± 6.44 degree

3.24 ± 2.05 degree p<0.001 Rotation value of peduncle 3.62 ± 2.22

degree

0.55 ± 0.76 degree p<0.001

The deflection angle of the disc

under the position fixed with

horizontal plane

15.48 ± 6.72 degree

3.75 ± 3.53 degree p<0.001 Total number of patient 40

Preoperative patients had a mean misalignment of the top vertebral of 5.33 cm on average After surgery of scoliosis correction, the average d misalignment was 1.20 cm The average rotation value of peduncle before surgery was 3.6 according to Nash-Moe classification The study results showed that the rotation value of peduncle after surgery was significantly improved with reliability p <0.001