Management of Thoracic Pseudoarthrosis in the Adult: Is Combine Surgery Necessary?

Information provided by

UC San Francisco, San Francisco, CA, USA

INTRODUCTION: In adult deformity surgery, pseudarthrosis remains an important cause of progressive deformity and post-operative pain. Revision surgery for pseudarthrosis in the lumbar spine is a difficult challenge with failure rates of up to 50 percent using posterior surgery alone. Management of pseudarthrosis of the thoracic spine has not been well described. The purpose of this paper is to review the long-term clinical and radiographic results of posterior only surgery for the management of pseudarthrosis in the thoracic spine.

METHODS: Retrospective review of consecutive patients treated for symptomatic pseudarthrosis in the thoracic spine after prior posterior spine fusion. Outcome variables included radiographic measures and clinical assessment. The surgical technique was a posterior extension osteotomy through the identified pseudarthrosis with reinstrumentation and autogenous bone grafting.

RESULTS: 10 patients (9 female, 1 male), average age 41.8 (range 17-72). Average clinical follow-up was 52.6 months (range 26-76), and average radiographic follow-up was 37.7 months (range 26-80). All patients had a prior posterior spine fusion with pseudarthrosis involving at least one level. An average of 7.3 degrees correction (range 1 to 17) was accomplished at each osteotomized segment. Average preoperative thoracic kyphosis was 62 degrees (range 41-105), and this improved to 52 degrees (range 33-64) post-operatively, and was maintained at most recent follow-up. At most recent follow-up, all patients demonstrated radiographic evidence of solid arthrodesis. There were no major complications among these patients. Clinical outcome demonstrated that 7/10 patients were somewhat or extremely satisfied with the results of surgery, and 8/10 patients would probably or definitely repeat surgery. The Modified Scoliosis Research Society Outcomes Instrument (MSRSI) demonstrated a total score averaging 76%. The Oswestry Disability Index (ODI) demonstrated an overall post-operative disability score of 18.8. Comparison of the ODI scores with each domain of the MSRSI demonstrated good correlation with the pain domain as expected (r=0.9). Cox regression analysis revealed that no domain within the MSRSI was a multivariate predictor of patient satisfaction.

CONCLUSIONS: Single stage posterior revision surgery with extension osteotomies through the regions of pseudarthrosis coupled with rigid internal fixation and autogenous bone grafting is an effective technique for management of pseudarthrosis of the thoracic spine. This technique improves regional sagittal deformity and leads to reliable arthrodesis. Combined anterior and posterior surgery was not necessary for effective management of thoracic pseudarthrosis in this series.