Retrospective study of prospectively collected data.
To analyze the incidence and the patterns of medial and lateral shoulder discordance among Lenke 1 and 2 patients.
Postoperative shoulder imbalance (PSI) is still common in Lenke 1 and 2 adolescent idiopathic scoliosis (AIS). This could be due to presence of medial dan lateral shoulder discordance.
One hundred fifty-one Lenke 1 and 2 AIS patients were recruited. Lenke 1 curves were subclassified into Lenke 1-ve (flexible) (proximal thoracic side bending [PTSB] Cobb angle <15°) and 1+ve curves (stiff) (PTSB Cobb angle between 15° and 24.9°). T1 tilt represented “medial shoulder balance” and radiological shoulder height (RSH) represented “lateral shoulder balance.” We categorized patients into three concordant shoulder pattern types (medial balanced/lateral balanced [MBLB], medial imbalanced+ve/lateral imbalanced+ve (MI+ve/LI+ve), medial imbalanced–ve/lateral Imbalanced–ve (MI–ve/LI–ve), and six discordant shoulder pattern types.
The mean age was 16.2 ± 5.7 years. Eighty-one patients (53.6%) had concordant pattern and 70 patients (46.4%) had discordant pattern. Lateral shoulder imbalance was noted in 35.1% of patients and medial shoulder imbalance in 43.7% of patients. In Lenke 1–ve curves, 35 patients (68.6%) had concordant shoulder imbalance with medial imbalanced–ve/lateral imbalanced–ve (MI–ve/LI–ve) being the commonest pattern (68.6%). In Lenke 1+ve curves, 33 patients (55.0%) had concordant shoulder pattern with medial balanced/lateral balanced (MB/LB) being the commonest type (57.6%). In Lenke 2 AIS, 27 patients (67.5%) had discordant pattern with medial imbalanced+ve/lateral balanced (MI+ve/LB) being the commonest pattern (44.4%) (P value = 0.002).
46.4% Lenke 1 and 2 AIS patients had shoulder discordant pattern. This was more prevalent in Lenke 2 curves (67.5%). In Lenke 1-ve (flexible) curves, MI–ve/LI–ve pattern was the commonest pattern. In Lenke 1+ve curves (stiff), there were almost equal number of concordant and discordant shoulder pattern. In Lenke 2 patients, the most common pattern was MI+ve/LB.
Level of Evidence: 4
Shoulder discordance was prevalent in 46.4% Lenke 1 and 2 patients. Most of the Lenke 1 −ve curves were concordant (68.6%). In Lenke 1 +ve, the prevalence of concordant (55.0%) and discordant (45.0%) shoulder pattern was almost equal. In Lenke 2, discordant shoulder imbalance was more common (67.5%).
Department of Orthopaedic Surgery, National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Address correspondence and reprint requests to Chris Yin Wei Chan, MD, MSOrth, Department of Orthopaedic Surgery, National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; E-mail: email@example.com
Received 6 June, 2018
Revised 16 August, 2018
Accepted 10 September, 2018
The manuscript submitted does not contain information about medical device (s)/drug (s).
No funds were received in support of this work.
No relevant financial activities outside the submitted work.