Evaluation of Surgical Correction of Adolescent Idiopathic Scoliosis by Transpedicular Screws and Rods.

Transpedicular screw fixation is a challenging procedure for the correction of deformity of Adolescent Idiopathic Scoliosis (AIS) in the dorso-lumbar spine. The inadvertently misplaced screws have a high risk of complications. The exactness of the pedicle screws is normally distinct as the screws axis being fully enclosed within the cortices of the pedicle. Evaluation of the surgical correction of adolescent idiopathic scoliosis by transpedicular screws and rods was done in single posterior dynamic approach. This prospective observational study was conducted in the National Institute of Traumatology and Orthopedic Rehabilitation, Dhaka and different Hospitals in Dhaka, Bangladesh from July 2015 to March 2017. Ten patients at the age >9 years and <19 years who were admitted with a diagnosis of AIS during the period of study. The pedicle is a power nucleus of the vertebra and offers a secure grip of all 3 columns. Pedicle screw instrumentation has advantages of rigid fixation with improved 3D correction and it has been accepted as a reliable method with a high margin of safety. Accurate placement of the pedicle screws is important to reduce possible irreversible complication. So, all cases were corrected by transpedicular screws and rods in single posterior approach. In every case fusion was done in selected segments. In this study out of 10 patients 7(70.0%) were 10 to 14 years of age and 3(30.0%) were 15 to 18 years. Mean age 9.51±2.13 years. Minimum 10 years and maximum 18 years. Majority 7(70.0%) of the patients were female and the rest 3(30.0%) male. Five (50.0%) presented with level of involvement, 3(30.0%) patients thoracic and 2(20.0%) patients had lumbar. Maximum 7(70.0%) presented right sided involvement and rest 3(30.0%) left sided involvement. Before surgical intervention 100% patients had rib hump and positive Adams forward bending test, 70.0% patients had asymmetry of shoulder and uneven hip and also 50% patients had pain. After surgical treatment with transpedicular screws and rods through posterior approach, 70% of patients improved in terms of deformity. The average major curve deformity as defined by Cobb angle measurements was measured to be 54.9°±9.9° (40°-68°) in pre-surgery. After surgery this deformity corrected to 16.0°±4.9° (10°-24°) on average as measured in erect posture posterior anterior and lateral view. This represents significant improvement average of 71.4±4.3% (64.6-75.09) (p<0.001). This correction was maintained at 24 months after surgery. Functional results assessed by Modified Macnab criteria, significant number of 7(70.0%) patients had excellent outcome, 2(20.0%) patients had good outcome, 1(10.0%) patients had fair outcome and no poor outcome. Ninety percent (90%) patients had satisfactory results. No patient deteriorates neurologically after surgery. It is concluded that satisfactory curve correction and maintenance thereof is possible in adolescent idiopathic scoliosis, with posterior instrumentation by transpedicular screw and rods with effective reduction of cost and associated risks.