Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Hyung-Youl Park x
  • All content x
Clear All Modify Search
Free access

Hyung-Youl Park, Young-Hoon Kim, Sang-Il Kim, Sung-Bin Han, and Kee-Yong Ha

OBJECTIVE

Few studies have addressed that dynamic sagittal imbalance can develop distal to the spinal fusion and cause sagittal malalignment, unlike proximal junctional kyphosis (PJK) in the proximal portion. The purpose of this study was to investigate risk factors between the 2 different types of postoperative sagittal imbalance after long fusion to the sacrum for the treatment of degenerative sagittal imbalance (DSI).

METHODS

Eighty patients who had undergone surgical correction for DSI were included. Radiographic measurements included spinopelvic parameters on whole-spine plain radiographs and degeneration of paravertebral muscles on MRI. Univariate and multivariate analyses for clinical and radiological factors were conducted for respective risk factors. In subgroup analyses, the 2 different types of postoperative sagittal imbalance were directly compared.

RESULTS

Forty patients (50%) developed postoperative sagittal imbalance; of these patients, 22 (55.0%) developed static proximal kyphosis from PJK, and 18 patients (45.0%) developed dynamic sagittal imbalance without PJK. The independent risk factors in proximal kyphosis were greater postoperative pelvic tilt (HR 1.11) and less change in sacral slope (SS) (HR 1.09), whereas there were more fusion levels (HR 3.11), less change in SS (HR 1.28), and less change in thoracic kyphosis (HR 1.26) in dynamic sagittal imbalance. Directly compared with the proximal kyphosis group, dynamic sagittal imbalance was more commonly found in patients who had less correction of sagittal parameters as well as fatty atrophy of the paravertebral muscles. Clinical outcomes in the dynamic sagittal imbalance group were superior to those in the proximal kyphosis group.

CONCLUSIONS

Optimal correction of sagittal alignment should be considered in long instrumented fusion for DSI, because insufficient correction might cause one of 2 different types of postoperative sagittal imbalance at different sites of decompression. Dynamic sagittal imbalance compared with proximal kyphosis was significantly associated with less correction of sagittal alignment, in conjunction with more fusion levels and degeneration of the paravertebral muscles.

Restricted access

Kee-Yong Ha, Eung-Ha Kim, Young-Hoon Kim, Hae-Dong Jang, Hyung-Youl Park, Chang-Hee Cho, Ryu-Kyoung Cho, and Sang-Il Kim

OBJECTIVE

The most catastrophic symptom of proximal junctional failure (PJF) following long instrumented fusion surgery for adult spinal deformity (ASD) is neurological deficits. Although previous reports have shown that PJF usually developed during the early postoperative period, some patients showed late neurological deficits. The aim of this study was to report the incidence, characteristics, and surgical outcomes of PJF with late neurological deficits.

METHODS

Patients surgically treated for ASD at a single institution were retrospectively reviewed. Among them, the patients requiring revision surgery for newly developed neurological deficits at least 6 months after the initial surgery were included. Patient demographic, radiographic, surgical, and clinical data were investigated. Neurological status was assessed using the Frankel grading system.

RESULTS

PJF with late neurological deficits developed in 18 of 385 patients (4.7%). The mean age at the onset of neurological deficits was 72.0 ± 6.0 years, and the median time from the initial surgery was 4.5 years. The most common pathology of PJF was adjacent disc degeneration and subsequent canal stenosis (11 patients). Five patients showed disc degeneration with aseptic bone destruction. Fractures at the upper instrumented vertebra (UIV), UIV + 1, and UIV + 2 occurred in 2, 3, and 2 patients, respectively. Ossification of the yellow ligament, which had not been found at the first surgery, was identified in 6 patients. Eight patients showed improvement of their neurological deficits and 10 patients showed no improvement by the final follow-up. Perioperative major complications occurred in 8 of 18 patients.

CONCLUSIONS

The incidence of PJF with late neurological deficits following ASD surgery was 4.7% in this cohort. The patients showed several morphological features. After revision surgery, perioperative complications were common and the prognosis for improved neurological status was not favorable.