Short fusion strategy for Lenke type 1 thoracic curve using pedicle screw fixation.

STUDY DESIGN

A retrospective case-control study

OBJECTIVE

Short fusion using pedicle screws (PSs) with an attempt to attain maximum correction of the main thoracic curve was conducted for patients with a Lenke type 1 curve, to prevent postoperative left shoulder elevation. The outcomes were compared with those of conventional surgery.

SUMMARY OF BACKGROUND DATA

Excessive correction of the main thoracic curve by PSs causes problematic left shoulder elevation even in a Lenke type 1 curve.

METHODS

Thirty-eight patients (3 male, 35 female, mean age 16.2 years, mean follow-up 24 mo) with Lenke type 1 curve underwent posterior corrective surgery using PSs. The upper instrumented vertebra was 1 level below the end vertebra in 14 patients (short, S group), and it was at the end vertebra in 24 patients (conventional, C group). There was no difference in the preoperative Cobb angle (51.8 vs. 58.0) or curve flexibility (49.7 vs. 46.1) between the 2 groups. Radiographic results, perioperative data, and scoliosis research society 22 scores were compared between the 2 groups.

RESULTS

The postoperative Cobb angle of the main curve after surgery was 13.2±5.7 degrees in the S group and 10.6±7.3 degrees in the C group (not significant). The clavicle angle was -2.1±2.8 degrees versus -2.7±2.6 degrees before surgery (not significant), and 0.8±2.3 versus 3.8±2.4 after surgery (P<0.05). The number of fused vertebrae, mean surgical time, and estimated blood loss were significantly lower in the S group than in the C group. The scoliosis research society 22 score at follow-up was not different between the 2 groups.

CONCLUSIONS

The short fusion strategy for a Lenke type 1 curve can produce equivalent correction of the main curve and clinical outcomes to conventional fusion strategy with less surgical time and blood loss, while maintaining better shoulder balance.