Proximal Fixation in Adolescent Scoliosis Lenke 1 and 3 Treated by Posteromedial Translation Using Sublaminar Bands: Transverse-pedicular Hook Claw Versus Transverse Hook-pedicular Screw Claw.

Study Design: This is retrospective comparative study.

Summary Or Background Data: Numerous studies have focused on the efficacy, safety, and restoration of thoracic kyphosis in adolescent idiopathic scoliosis surgery using posteromedial translation method with sublaminar bands and hook claws at the top. The relevance of exchanging the penultimate anchor, that is, the pedicle hook with a pedicle screw in a hybrid construction has not yet been assessed.

Objective: Our objective was to assess, in adolescent scoliosis Lenke 1 and 3 operated by posteromedial translation using sublaminar bands, the proximal fixation claw influence (transverse-pedicular hook vs. transverse hook-pedicular screw) for postoperative correction and the proximal junctional kyphosis (PJK) at 2 years follow-up.

Materials And Methods: A comparative monocentric retrospective study included adolescent idiopathic scoliosis thoracic requiring surgery, between 2015 and 2017, with 2 years follow-up. Clinical (complications, revision surgery, and scoliosis research society-30) and radiographic (coronal and sagittal parameters) assessment were reported. Radiologic PJK was defined by a proximal junctional angle increase of 10 degrees or more between postoperative period and the last follow-up.

Results: Sixty patients (age at surgery=16±2 y; mean Cobb angle=58.2±12 degrees) were divided into 2 similar groups according to upper fixation: transverse-pedicular hook (H-H) and transverse hook-pedicle screw (S-H). No statistical differences were found for correction parameters (P>0.05). We reported 2 cases of PJK in H-H group (N=2/30=6.6%) and none in S-H group (N=0/30) (P=0.1) none requiring revision. No infectious or neurological events were reported. Mean scoliosis research society-30 was 126±12.7 in H-H group whereas 129.3±10 in S-H group (P=0.4).

Conclusions: No differences in postoperative correction and clinical results at 2 years follow-up were found. A claw with transverse-pedicular hook increase proximal junctional angle without significant increase on radiographic PJK incidence compared with a claw with transverse hook and pedicle screws.