Elsevier

World Neurosurgery

Volume 127, July 2019, Pages e467-e473
World Neurosurgery

Original Article
Posterior Multiple-Level Asymmetrical Ponte Osteotomies for Rigid Adult Idiopathic Scoliosis

https://doi.org/10.1016/j.wneu.2019.03.173Get rights and content

Objective

To evaluate the efficacy and safety of posterior multiple-level asymmetrical Ponte osteotomies for rigid adult idiopathic scoliosis.

Methods

A retrospective study was conducted for adult patients with rigid idiopathic scoliosis (flexibility of main curve <25%) who underwent one-stage multiple-level asymmetrical Ponte osteotomies with a minimum of 2-year follow-up between February 2009 and November 2015. The demographic data and surgical issues were collected, and the improvement of clinical function scores and radiologic parameters were obtained after surgery and during the follow-up to assess deformity correction, spinal balance, and clinical outcome.

Results

A total of 49 patients were included (10 male and 39 female) in this study, with an average age of 26.53 years old. The average follow-up was 28.37 ± 6.98 months. All the cases presented a significant improvement of the main curve and focal kyphosis from 85.62 ± 19.80° to 36.19 ± 16.74° and 53.98 ± 26.80° to 30.88 ± 18.69°, with a mean correction rate of 57.73% and 41.23%. The postoperative coronal and sagittal parameters were all significantly improved, except coronal balance. The mean operative time and blood loss were 267.86 ± 54.49 minutes and 838.78 ± 538.93 mL. All the clinical function scores of patients were significantly improved at the final follow-up. Only one patient had a complication related to surgical incision, with no neurologic complications occurring.

Conclusions

The surgical procedure of multiple-level asymmetrical Ponte osteotomy is a safe and effective technique, with reduced operation time, blood loss, and complications, and may offer an appropriate option to address the problems of rigid adult idiopathic scoliosis.

Introduction

Adult idiopathic scoliosis (AdIS) is a spine deformity that does not develop de novo in patients older than 18 years old, that is, the untreated patient with adolescent idiopathic scoliosis (AIS) who followed the natural history with aging. The prevalence rate is about 2%−4% among adults younger than 45 years old.1 Some patients with AdIS may not proceed with surgical treatment since they are asymptomatic in their early age. Meanwhile, many patients and families chose to delay surgery because of their concerns regarding the influence on spinal growth, daily activities, patients' studies, and psychological states.2, 3 However, untreated or uncontrolled spinal deformities may lead to pulmonary functional impairment, symptoms of pain, and radiculopathy due to the curve progression as patients age.

Despite advances in technology that have allowed many spine surgeries to be performed, spinal correction surgery has always been a challenging and risky procedure. When it comes to adults, the curve flexibility of patients with AdIS, unlike patients with AIS, will decrease with aging, and the treatment outcome often is characterized by lower correction outcome. Therefore, maintaining the balance between the aggressive procedures to enhance the correction outcome and their potential risks is important, as quality and safety are a priority consideration of patients and families.

It has become increasingly common to correct these deformities with all pedicle screw constructs via posterior-only approaches in recent years.4, 5, 6 Meanwhile, since the Smith−Petersen osteotomy was described in 1945, osteotomy technology in the decades to follow has been greatly developed.7 However, correction and flexibility were not achieved by Smith−Petersen osteotomy shortening the posterior column but lengthening the anterior column, which may increase the risk of neurologic complications.8 As Ponte et al.9 further expanded the resection of posterior elements and described the Ponte osteotomy in 1984, it has been widely used in the treatment of spine deformity by a shortening of the posterior column, particularly in sagittal correction.10 It is a versatile technique that can be performed safely and rapidly to enhance curve flexibility and correction of gradual kyphosis or scoliosis.10, 11, 12, 13, 14, 15 Although a single-segment Ponte osteotomy may provide limited correction capability, this procedure can be applied to multiple segments with minimal bleeding and risks. However, to the best of our knowledge, there is no literature to report about the potential value of multiple-level asymmetrical Ponte osteotomies (MAPO) for rigid AdIS. Thus, the purpose of this study was to evaluate the efficacy and safety of posterior MAPO for rigid AdIS.

Section snippets

Study Sample

A retrospective study was conducted to evaluate radiologic and clinical outcomes for adult patients with rigid idiopathic scoliosis (flexibility of main curve <25%), who underwent one-stage posterior MAPO with a minimum of 2 years' follow-up between February 2009 and November 2015 after appropriate institutional review board approval. Exclusion criteria included other etiologies of scoliosis, history of spinal surgery, or anterior release.

Data Collection

The surgical issues (fusion levels, pedicle screws

Results

A total of 49 patients (10 male and 39 female) with rigid AdIS was included and 36 patients reached the severe standard (the Cobb angle of the main curve >80°). The average follow-up was 28.37 ± 6.98 months, and the detailed demographic data and preoperative characteristics of the curve in this case series are summarized (Tables 1 and 2). The average segments of multiple-level Ponte osteotomies that patients received were 4.39 ± 0.95 (range from 3 to 6). The average fusion levels of these

Discussion

It is now well established that untreated scoliosis in adults, especially the severe and rigid types, can lead to pain, neurologic symptoms, cardiopulmonary compromise, progression of deformity, trunk imbalance, or daily living disability. However, delaying surgery into adulthood is not uncommon due to concerns from patients and family members. Moreover, unlike a moderate and flexible spine in patients with AIS, the spine of patients with AdIS is stiffer, which make the surgery for adult

Conclusions

The surgical procedure of multiple-level asymmetrical Ponte osteotomy is a safe, easy-to-operate, and effective technique that can correct spine deformity to some extent and restore the spinal alignment with reduced operation time, blood loss, and complications and may offer an appropriate option to address the problems of rigid adult idiopathic scoliosis.

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    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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