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Postoperative shoulder imbalance in Lenke Type 1A adolescent idiopathic scoliosis and related factors.

Matsumoto M, Watanabe K, Kawakami N, Tsuji T, Uno K, Suzuki T, Ito M, Yanagida H, Minami S, Akazawa T - BMC Musculoskelet Disord (2014)

Bottom Line: Clavicle angle at follow-up correlated weakly but significantly with preoperative clavicle angle (r = 0.34, p = 0.001) and with the correction rates of the main thoracic curve (r = 0.34, p = 0.001); it correlated negatively with the proximal curve spontaneous correction rate (r=-0.21, p = 0.034).The clavicle angle at follow-up was significantly larger in patients with PS-only constructs (PS 2.1 degrees vs. hybrid 0.9, p = 0.02), and tended to be smaller in patients with distal adding-on (adding-on 1.1 vs. non adding-on 2.0, p = 0.09).PSI was more common with better correction of the main curve (using PS constructs), in patients with a larger preoperative clavicle angle, and with a larger and more rigid proximal curve.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Keio University, Shinanomachi 35, Shinjuku-ku, Tokyo #160-8582, Japan. morio@a5.keio.jp.

ABSTRACT

Backgrounds: The purpose of this study was to investigate the occurrence and factors associated with postoperative shoulder imbalance (PSI) in Lenke type 1A curve.

Methods: This study included 106 patients with Lenke Type 1A curve who were followed up more than two years after posterior correction surgery. Pedicle screw (PS) constructs were used in 84 patients, and hybrid constructs in 22. The upper instrumented vertebra was rostral to the upper-end vertebra (UEV) in 70 patients, at UEV in 26, and below UEV in 10. The clavicle angle and T1 tilt angle were measured as PSI indicators, and correlations between radiographic parameters of shoulder balance and other radiographic parameters and associations between PSI and clinical parameters were investigated. For statistical analyses, paired and unpaired t-tests were used.

Results: The mean Cobb angles of the main and proximal thoracic curves were 54.6 ± 9.5 and 26.7 ± 7.9 degrees before surgery, 14.5 ± 7.5, and 14.9 ± 7.1 at follow-up. Clavicle angle and T1 tilt angle were -2.9 ± 2.8 and -2.6 ± 6.3 before surgery, 2.4 ± 2.8 and 4.4 ± 4.3 immediately after surgery, and 1.8 ± 2.1 and 3.4 ± 5.5 at follow-up. Twenty patients developed distal adding-on. Clavicle angle at follow-up correlated weakly but significantly with preoperative clavicle angle (r = 0.34, p = 0.001) and with the correction rates of the main thoracic curve (r = 0.34, p = 0.001); it correlated negatively with the proximal curve spontaneous correction rate (r=-0.21, p = 0.034). The clavicle angle at follow-up was significantly larger in patients with PS-only constructs (PS 2.1 degrees vs. hybrid 0.9, p = 0.02), and tended to be smaller in patients with distal adding-on (adding-on 1.1 vs. non adding-on 2.0, p = 0.09).

Conclusions: PSI was more common with better correction of the main curve (using PS constructs), in patients with a larger preoperative clavicle angle, and with a larger and more rigid proximal curve. Distal adding-on may compensate for PSI.

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Related in: MedlinePlus

A 17-year-old female who underwent posterior correction and fusion using PS constructs. She developed PSI with good correction of the main thoracic curve. The PSI improved at follow-up, as distal adding-on developed (white arrow). A. Before surgery, B. Immediately after surgery, C. At the two-year follow-up.
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Fig2: A 17-year-old female who underwent posterior correction and fusion using PS constructs. She developed PSI with good correction of the main thoracic curve. The PSI improved at follow-up, as distal adding-on developed (white arrow). A. Before surgery, B. Immediately after surgery, C. At the two-year follow-up.

Mentions: PSI may be compensated for by the development of distal adding-on (Figure 2). As yet, it is not known whether distal adding-on develops independently or correlatively to PSI to rebalance the left shoulder elevation. If correlatively, surgeons should do their best to prevent PSI, since distal adding-on can eventually result in symptomatic degenerative changes of the lumbar spine [21]. Several surgical options to prevent PSI have been reported, including extending the fusion levels to the rostral vertebrae (such as T1 and T2) and tempering the correction of the main curve by setting the UIV below the UEV (short fusion strategy, as reported by Matsumoto et al. [22]), or by limiting the correction obtained within the instrumented vertebrae [12].Figure 2


Postoperative shoulder imbalance in Lenke Type 1A adolescent idiopathic scoliosis and related factors.

Matsumoto M, Watanabe K, Kawakami N, Tsuji T, Uno K, Suzuki T, Ito M, Yanagida H, Minami S, Akazawa T - BMC Musculoskelet Disord (2014)

A 17-year-old female who underwent posterior correction and fusion using PS constructs. She developed PSI with good correction of the main thoracic curve. The PSI improved at follow-up, as distal adding-on developed (white arrow). A. Before surgery, B. Immediately after surgery, C. At the two-year follow-up.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4230354&req=5

Fig2: A 17-year-old female who underwent posterior correction and fusion using PS constructs. She developed PSI with good correction of the main thoracic curve. The PSI improved at follow-up, as distal adding-on developed (white arrow). A. Before surgery, B. Immediately after surgery, C. At the two-year follow-up.
Mentions: PSI may be compensated for by the development of distal adding-on (Figure 2). As yet, it is not known whether distal adding-on develops independently or correlatively to PSI to rebalance the left shoulder elevation. If correlatively, surgeons should do their best to prevent PSI, since distal adding-on can eventually result in symptomatic degenerative changes of the lumbar spine [21]. Several surgical options to prevent PSI have been reported, including extending the fusion levels to the rostral vertebrae (such as T1 and T2) and tempering the correction of the main curve by setting the UIV below the UEV (short fusion strategy, as reported by Matsumoto et al. [22]), or by limiting the correction obtained within the instrumented vertebrae [12].Figure 2

Bottom Line: Clavicle angle at follow-up correlated weakly but significantly with preoperative clavicle angle (r = 0.34, p = 0.001) and with the correction rates of the main thoracic curve (r = 0.34, p = 0.001); it correlated negatively with the proximal curve spontaneous correction rate (r=-0.21, p = 0.034).The clavicle angle at follow-up was significantly larger in patients with PS-only constructs (PS 2.1 degrees vs. hybrid 0.9, p = 0.02), and tended to be smaller in patients with distal adding-on (adding-on 1.1 vs. non adding-on 2.0, p = 0.09).PSI was more common with better correction of the main curve (using PS constructs), in patients with a larger preoperative clavicle angle, and with a larger and more rigid proximal curve.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Keio University, Shinanomachi 35, Shinjuku-ku, Tokyo #160-8582, Japan. morio@a5.keio.jp.

ABSTRACT

Backgrounds: The purpose of this study was to investigate the occurrence and factors associated with postoperative shoulder imbalance (PSI) in Lenke type 1A curve.

Methods: This study included 106 patients with Lenke Type 1A curve who were followed up more than two years after posterior correction surgery. Pedicle screw (PS) constructs were used in 84 patients, and hybrid constructs in 22. The upper instrumented vertebra was rostral to the upper-end vertebra (UEV) in 70 patients, at UEV in 26, and below UEV in 10. The clavicle angle and T1 tilt angle were measured as PSI indicators, and correlations between radiographic parameters of shoulder balance and other radiographic parameters and associations between PSI and clinical parameters were investigated. For statistical analyses, paired and unpaired t-tests were used.

Results: The mean Cobb angles of the main and proximal thoracic curves were 54.6 ± 9.5 and 26.7 ± 7.9 degrees before surgery, 14.5 ± 7.5, and 14.9 ± 7.1 at follow-up. Clavicle angle and T1 tilt angle were -2.9 ± 2.8 and -2.6 ± 6.3 before surgery, 2.4 ± 2.8 and 4.4 ± 4.3 immediately after surgery, and 1.8 ± 2.1 and 3.4 ± 5.5 at follow-up. Twenty patients developed distal adding-on. Clavicle angle at follow-up correlated weakly but significantly with preoperative clavicle angle (r = 0.34, p = 0.001) and with the correction rates of the main thoracic curve (r = 0.34, p = 0.001); it correlated negatively with the proximal curve spontaneous correction rate (r=-0.21, p = 0.034). The clavicle angle at follow-up was significantly larger in patients with PS-only constructs (PS 2.1 degrees vs. hybrid 0.9, p = 0.02), and tended to be smaller in patients with distal adding-on (adding-on 1.1 vs. non adding-on 2.0, p = 0.09).

Conclusions: PSI was more common with better correction of the main curve (using PS constructs), in patients with a larger preoperative clavicle angle, and with a larger and more rigid proximal curve. Distal adding-on may compensate for PSI.

Show MeSH
Related in: MedlinePlus