Shoulder Balance In Patients Research Articles

Relationship between the course of postoperative pelvic axis rotation and shoulder balance in patients with Lenke types 1 and 2 adolescent idiopathic scoliosis

BackgroundPosteroanterior radiographs of patients with adolescent idiopathic scoliosis (AIS) show bilateral differences in the iliac wings. This is due to pelvic axis rotation (PAR) associated with scoliosis. We often encounter cases wherein the PAR changes with surgery and postoperatively. We investigated the course of preoperative PAR and the relationship between PAR and shoulder balance in patients with Lenke 1,2 AIS. MethodsIn total, 28 patients with Lenke 1,2 AIS undergoing scoliosis correction were included. The PAR and shoulder parameters were measured on posteroanterior radiographs. The correlation between the measured parameters and the extent of changes in each parameter was also examined. ResultsEleven patients (39.3 %) underwent preoperative PAR. Six patients (21.4 %) showed a greater change in PAR from 1 week to 2 years postoperatively. The rotation did not change significantly from preoperatively to immediately postoperatively but changed during the first three months postoperatively. The rotation group had significantly more balanced shoulders at 2 years (P = 0.025). The rotation group had a greater change in shoulder balance in the postoperative course significantly (P < 0.05). The extent of change in pelvic rotation from 1 week to 2 years postoperatively correlated with the extent of change in shoulder balance. ConclusionThe PAR in patients with Lenke 1,2 AIS significantly changed during 3 months postoperatively. Patients with Lenke 1,2 AIS with preoperative PAR can be expected to have postoperative shoulder rebalancing.

Does Sacral Slanting Affect Postoperative Shoulder Balance in Patients With Lenke Type 2A Adolescent Idiopathic Scoliosis?

Even minor sacral slanting can influence T1 tilt and shoulder balance. Yet, the relationship between sacral slanting and postoperative shoulder imbalance (PSI) has not been previously explored. To determine risk factors for PSI in Lenke 2A adolescent idiopathic scoliosis (AIS) patients, with an emphasis on sacral slanting. The study encompassed 96 consecutive patients who had undergone posterior correction and fusion surgery for Lenke type 2A AIS. Patients were grouped into PSI(+) and PSI(-) based on postoperative outcomes. Additionally, they were classified into left-sided slanting, no slanting, and right-sided slanting groups according to the degree of sacral slanting. Various radiological measures were compared. Patients in the PSI(+) group exhibited a smaller preoperative proximal thoracic curve and a higher main thoracic curve correction rate than those in the PSI(-) group. The presence or absence of sacral slanting did not exhibit a significant variation in PSI occurrence. However, the right-sided sacral slanting group showed a larger delta radiologic shoulder height compared to the other 2 groups (7.1 mm vs. 1.5 & 3.3 mm). Sacral slanting was not directly linked to the development of PSI. Despite the common postoperative elevation of the left shoulder, the shoulder height differences decreased over the follow-up period. Especially in cases with a right-sided tilted sacrum, the PSI demonstrated progressive improvement, with an associated increase in the rightward distal wedging angle, leading to distal adding-on.

Shoulder Balance in Adult Spinal Deformity Patients Undergoing Selective Lumbar Fusion.

Retrospective review. To analyze if shoulder balance continues to change in the postoperative period in patients undergoing selective lumbar fusion for adult spinal deformity (ASD), and secondarily, analyze if shoulder balance correlates with health-related quality of life (HRQOL) outcomes. Shoulder balance in patients with ASD is poorly understood and has largely been extrapolated from adolescent scoliosis literature. Adult patients who underwent selective lumbar fusion (upper instrumented vertebra: Τ9-Τ12, lower instrumented vertebra: L4-Pelvis) for thoracolumbar or lumbar scoliosis (cobb angle > 30°) or sagittal plane deformity with thoracic compensatory curves (cobb angle > 10°) were identified. The clavicular angle (CA) was used to quantify shoulder balance. Shoulder balance was categorized into three groups postoperatively (balanced: CA <2°, mild imbalance: CA 2°-4°, severe imbalance: CA >4°). The average CA and proportion of patients in each shoulder balance group were compared at each postoperative period. Patients with 1-year postoperative HRQOL scores were identified. Eighty-six patients were included. The preoperative CA was 2.7 ± 2.3° and did not significantly change at discharge (2.9 ± 2.4°), 6-weeks (2.5 ± 2.1°), 6-months (2.4 ± 2.2°), 1-year (2.4 ± 2.5°), or 2-years (2.3 ± 1.5°) postoperatively. The proportion of patients in each shoulder balance group did not significantly change from discharge to 6-weeks, 6-months, 1-year or 2-years postoperatively (P > 0.1). At 1-year follow-up, the CA demonstrated no significant correlation with Oswestry Disability Index, Scoliosis Research Society (SRS)-22 score, or SRS-22 subscores. There was no significant association between shoulder balance group and Oswestry Disability Index, SRS-22 score, or SRS-22 subscores. In patients with ASD undergoing selective lumbar fusion, shoulder balance did not change over the postoperative period. From a functional standpoint, shoulder balance demonstrated no correlation with HRQOL scores. In patients undergoing selective lumbar fusion for ASD, shoulder balance may not spontaneously correct over the postoperative period, but this may not be of functional consequence.Level of Evidence: 4.

Shoulder balance in patients with Lenke type 1 and 2 idiopathic scoliosis appears satisfactory at 2years following anterior vertebral body tethering of the spine.

Shoulder balance is an important factor for patient satisfaction following surgery for idiopathic scoliosis (IS). There is no literature reporting the effect of anterior vertebral body tethering (AVBT) on shoulder balance. The purpose of this study was to report the prevalence of postoperative shoulder imbalance in patients undergoing AVBT for IS. In this retrospective case series, patients enrolled in a multicenter scoliosis registry who underwent AVBT from 2013 to 2017 in two Canadian centers were identified. The primary outcome was shoulder imbalance, defined as an absolute radiographic shoulder height of > 2cm, at 2 years postoperatively (follow-up range: 22-30months). Clavicular angle and T1 tilt angle were also investigated. Of the 50 patients identified (92% female; preoperative age: 11.9 ± 1.4years), there were 43 (86%) patients with Lenke 1 and 7 (14%) patients with Lenke 2 curves. The mean Cobb angles of the proximal thoracic and main thoracic curves were 22.8° ± 8.8° and 49.4° ± 8.5° preoperatively and 13.1° ± 7.5° and 24.9° ± 9.5° at a mean follow-up time of 2.1years. Absolute clavicular angle and T1 tilt angle were 2.8° ± 2.2° and 4.8° ± 3.5° preoperatively and 2.2° ± 1.7° and 4.7° ± 4.2° at 2-year follow-up. Preoperatively, absolute shoulder height averaged 15.6 ± 10.4mm, and 15 (30%) patients had shoulder imbalance. At 2-year follow-up, absolute shoulder height averaged 11.2 ± 8.3mm, and 8 (16%) patients had shoulder imbalance. Of the patients who had acceptable shoulder balance preoperatively, 4 (11.4%) became imbalanced at 2 years postoperatively. Postoperative shoulder imbalance in this early group of patients with IS undergoing AVBT was seen in 16% of patients, a reduction from 30% preoperatively. These results likely reflect the potential of the proximal thoracic curve to correct spontaneously following AVBT. Level III.

The amount of surgical correction of the main thoracic curve is the best predictor of postoperative clinical shoulder balance in patients with Adolescent Idiopathic Scoliosis.

This study sought to analyze factors that predict postoperative shoulder balance based on clinical photography. Based on inclusion criteria, 132 AIS patients were selected. Age, sex, and BMI of each patient were recorded. The following parameters were recorded from radiographs: clavicle angle, T1 tilt, the upper instrumented vertebra (UIV), lowest instrumented vertebra (LIV) thoracic kyphosis, lumbar modifier, preoperative and postoperative proximal thoracic Cobb angle, preoperative and postoperative main thoracic Cobb angle, and preoperative and postoperative thoracolumbar Cobb angle, if applicable. Two spine surgeons independently assigned the photographs shoulder balance grades based on the WRVAS (1-2 = Acceptable, 3-5 = Unacceptable). Surgeons were blinded as to whether the photographs were taken preoperatively or postoperatively. The shoulders were also graded as right high, left high, or balanced. Of all variables analyzed, only main thoracic Cobb angle correction (MTCAC) showed a statistically significant relationship with postoperative shoulder balance (p = 0.01). Odds of having unacceptable shoulder balance increase by 21% for every 5° increase in MTCAC (Adjusted OR = 1.21, 95% CI 1.015-1.452). The odds of unbalanced shoulders are 4.7 times higher for patients whose MTCAC is 40° or more (p = 0.001). Inter-rater reliability was excellent (k =0 .7). Intra rater reliability was perfect for Surgeon 1 (kappa = 1.0) and showed substantial agreement for Surgeon 2 (kappa = 0.8) CONCLUSIONS: Greater correction of main thoracic Cobb angle predicts unacceptable postoperative shoulder balance with 40° of correction signifying a major dichotomy between acceptable and unacceptable.

Hooks at the Upper Instrumented Vertebra Can Adjust Postoperative Shoulder Balance in Patients with Adolescent Idiopathic Scoliosis: 5 Years or More of Follow-up.

Study DesignA retrospective cohort study.PurposeThis study aims to investigate postoperative shoulder imbalance (PSI) ≥5 years postoperatively in patients who underwent posterior spinal fusion using hooks at the upper instrumented vertebra (UIV) for Lenke type 1 adolescent idiopathic scoliosis (AIS).Overview of LiteratureStudies have reported PSI due to excessive correction of the main thoracic curve.MethodsWe examined 56 patients with AIS who underwent a posterior spinal fusion with hooks at the UIV from 2004 to 2010. Of these, we enrolled 14 patients who underwent surgery, at least, 5 years ago. X-rays and Scoliosis Research Society-22 (SRS-22) questionnaire were administered. To evaluate the shoulder balance, T1 vertebral tilt angle (T1 tilt), clavicle angle, and radiographic shoulder height (RSH) were measured. PSI was considered as the absolute value of the postoperative RSH being ≥20 mm. Based on radiographs obtained immediately postoperatively, we divided patients into two groups as follows: the balanced group (absolute value of RSH <20 mm) and imbalanced group (absolute value of RSH ≥20 mm).ResultsThe frequency of PSI was 28.6% immediately postoperatively, 0% 2 years postoperatively, and 7.1% at the last follow-up. In the balanced group, PSI did not occur even at 2 years postoperatively or at the last follow-up. In the imbalanced group, PSI was improved in all patients 2 years postoperatively and all patients, except one patient, at the last follow-up. No significant differences were noted in the frequency of distal adding-on at 2 years postoperatively or the last follow-up between the balanced group and the imbalanced group. We observed moderate negative correlations between the absolute value of T1 tilt and the SRS-22 pain and satisfaction at the last follow-up.ConclusionsHooks at the UIV could adjust the shoulder balance to avoid long-term PSI in patients with AIS.

Assessment of Change of Shoulder Balance in Patients with Adolescent Idiopathic Scoliosis after Correctional Surgery.

To identify factors that influence shoulder balance and to determine whether a model can be made to predict shoulder balance after corrective surgery. This is a retrospective study in which we examined the records of with adolescent idiopathic scoliosis (AIS) patients who underwent single posterior spinal correction and fusion using all pedicle screws with derotation in our institution between January 2008 and June 2010. For the radiographic outcome measurement, we measured the preoperative lumbar curve, the main thoracic curve, and their difference (L_TH_D), and the degree of correction of the lumbar curve, the main thoracic curve, and their difference (c_L_TH_D) to evaluate their influence on postoperative shoulder balance. The preoperative flexibility of the proximal non-fusion curve on the immediate postoperative tilt of the upper endplate of the uppermost vertebra of fusion segments (Up_FuS) was used to evaluate and predict the shoulder balance at follow-up. For patients who had shoulder balance at follow-up, the average balance time was 7.1 months, and in most of them, balance was detected within 12 months. The main thoracic curve has the greatest influence on preoperative shoulder tilt and correction of the main thoracic curve has the greatest influence on the postoperative alteration in shoulder balance. To evaluate the influence on the preoperative shoulder tilt, the lumbar curve must be larger than the main thoracic curve both pre operatively and postoperatively. If the preoperative flexibility of the proximal non-fusion curve on the immediate postoperative Up_FuS includes the horizontal line (With Horizontal group), shoulder balance can be ensured. The postoperative Up_FuS can be evaluated based on the preoperative Up_FuS and the degree of correction of the lumbar and main thoracic curves. Shoulder balance can be ensured in patients in the With Horizontal group after surgery. If the preoperative Up_FuS and the degree of correction of the main thoracic curve and the lumbar curve are considered in the preoperative plan, the desired postoperative Up_FuS can be achieved, ensuring shoulder balance at follow-up.

Defining 2 Components of Shoulder Imbalance

A single-center prospective case series. To examine 2 features of shoulder asymmetry (clavicle tilt and trapezial prominence) and their correlation with radiographical parameters. Shoulder imbalance is one of the more notable aspects of clinical deformity due to scoliosis. However, a discrepancy between radiographical and clinical shoulder balance in patients with adolescent idiopathic scoliosis (AIS) has been reported. A consecutive series of 113 preoperative right main thoracic Lenke 1 and 2 AIS curves were included. Clavicle angle (tilt), trapezial angle, and ratio of left to right trapezial area were measured on clinical photos. These were correlated with radiographical measurements of T1 tilt, first rib angle, curve magnitudes, and thoracic and lumbar apical translation to C7 plumb line and center sacral vertical line. The average age was 14.1 years. There were 82 Lenke 1 and 31 Lenke 2 curves with an average thoracic Cobb of 52.1º. The clinical clavicle angle was in the range of -10.6º to +5.2º ("+" defined as high on the left) and had modest correlation with T1 tilt, thoracic curve size, and thoracic apical deviation (r = 0.417, 0.437, and 0.408, respectively). Medial shoulder trapezial prominence as measured by the trapezial angle (range: -16.7 to +9.9) and trapezial area ratio (natural log of ratio range: -1.15 to +0.80) correlated well with the radiographical measurements of T1 tilt, first rib angle, and upper thoracic curve size (trapezial angle: 0.713, 0.679, and 0.686; trapezial area ratio: 0.597, 0.595, and 0.653, respectively). Our analysis suggests that there are 2 distinct regions (lateral and medial) of shoulder height asymmetry. Medial differences reflected in trapezial prominence relate to deformity created by upward tilted proximal ribs and T1 tilt. Lateral differences in shoulder symmetry as reflected in the clavicle angle correlate weakly with radiographical measures. This suggests that correction of trapezial prominence may be more predictable compared with clavicle angulation after scoliosis surgery.

The effect of a vertical expandable prosthetic titanium rib on shoulder balance in patients with congenital scoliosis

To evaluate the effect of a vertical expandable prosthetic titanium rib (VEPTR) on shoulder balance in patients with congenital scoliosis. Fifteen patients had a thoracic congenital scoliosis. The Cobb angles of the thoracic primary curves were measured. Preoperative measurements of the coracoid height difference (CHD; expressed in millimeters) and the clavicular tilt angle difference (CTAD; expressed in degrees) were performed for all patients. All of the patients were treated with VEPTR open wedge thoracostomy. There was a statistically significant improvement in thoracic Cobb angle. At the end of follow-up there was a significant improvement in CHD; all but three of the patients had CHD<9mm. Preoperatively, CTAD was 8.9°. It improved to 4.4° postoperatively and significantly decreased to 3.9° by the end of follow-up. Complications included device migration (one patient), infection (one patient), and pedicle screw loosening or displacement (two patients). VEPTR is able to produce a modest intraoperative correction of shoulder imbalance.