P0844 - Partial Instrumentation Removal for Implant Prominence and Pain after Posterior Spinal Fusion in Adolescent Idiopathic Scoliosis Patients

Background/Purpose: The purpose of this study was to report the outcomes of patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF) that later underwent partial implant removal due to pain secondary to implant prominence.

Methods: Retrospective review was conducted on all AIS patients from January 2009 to January 2019. Inclusion criteria were diagnosis of AIS and previous PSF with segmental instrumentation with subsequent partial implant removal due to pain secondary to prominent implants. Medical charts and radiographs were reviewed for resolution of pain and deformity progression after partial implant removal.

Results: During the study period, 516 patients underwent PSF for AIS. A total of 9 patients, representing 1.7% (9/516) of the AIS patient population, had a partial implant removal for pain and tenderness directly overlying prominent spinal instrumentation. Mean age was 18 ± 2 (range: 14-20) years at partial implant removal and mean follow-up was 19.0 ± 18.3 (range: 0.4-56.9) months. Mean time from PSF to partial implant removal was 57.4 ± 18.7 (range: 31.2-85.2) months. Prior to implant removal, physical exam revealed segments of prominent, palpable spinal instrumentation in each patient. All patients had pain and tenderness localized to the soft tissue overlying the prominent implants. Unilateral partial implant removal was performed in 88% (8/9) of patients, and an average of 3 pedicle screws or rib hooks were removed per patient. Following partial implant removal, 100% (9/9) of patients had complete resolution of pain and returned to full activities. In the 5 patients with at least 1 year of follow-up after partial implant removal, the mean change in magnitude of the spinal deformity was 3 degrees or less in the coronal and sagittal planes, which is within measurement variability. No patient experienced a change in deformity of greater than 8 degrees in either the coronal or sagittal plane after partial implant removal.

Conclusions: Removal of the prominent, symptomatic segments of instrumentation resulted in complete resolution of pain, facilitated return to full functionality, and was not associated with significant change in deformity (mean change = 3 degrees) in all of our patients. In AIS patients that have had spinal fusion and later present with focal pain and tenderness secondary to prominent instrumentation, surgeons should consider performing partial spinal implant removal.