Long-term surgical outcomes of idiopathic versus congenital scoliosis: A retrospective study from a tertiary referral center

INTRODUCTION

Scoliosis is a three-dimensional spinal deformity characterized by lateral curvature exceeding 10°, often accompanied by vertebral rotation.^[1] It is classified into idiopathic, congenital, and neuromuscular types, with idiopathic scoliosis (IS) being the most common, accounting for 80% of cases.^[2] Congenital scoliosis (CS) results from vertebral malformations during fetal development, leading to asymmetric growth and potential progression over time. Both conditions can significantly impact patients’ quality of life (QoL), warranting medical and surgical intervention.^[3] Surgical treatment is usually indicated for progressive or severe scoliosis to achieve spinal alignment, prevent further deformity, and improve functional outcomes. Various surgical techniques, including posterior spinal fusion and instrumentation, are used depending on the severity and type of scoliosis.^[4] Despite advancements in surgical management, there is limited evidence comparing long-term post-operative outcomes between IS and CS patients. Existing studies primarily focus on short- to midterm outcomes, with few evaluating the long-term impact on functional status, pain, and QoL.^[5-7] Given the differing pathophysiology and progression of these two conditions, understanding their respective post-operative trajectories is critical for optimizing treatment strategies and patients’ pre-operative counseling.

This study aimed to focus on this knowledge gap and compare the long-term surgical outcomes of patients with idiopathic and CS. By analyzing clinical parameters, it tries to provide insights into functional recovery, QoL, and overall patient satisfaction, contributing to improved scoliosis treatment protocols.

MATERIALS AND METHODS

This retrospective cross-sectional study was conducted at our two major referral centers. The study’s population included adolescent patients aged 10–20 years who underwent definitive spinal surgery between October 2007 and December 2021 due to IS or CS. The cases were identified through the hospital records. Our inclusion criteria were a confirmed diagnosis of IS or CS, definitive corrective surgery (posterior spinal fusion and fixation with pedicular screw and rod) performed within the study period, availability of complete medical records, and a minimum follow-up duration of 24 months. We excluded patients with adult spine deformities aged over 20 years, paralytic cases, those who required anterior or both anterior and posterior approaches, and patients who had undergone “growth-respecting” surgeries, such as traditional growing rods, magnetic expansion control rods, vertebral body tethering, and other similar non-definitive procedures. Eligible patients were contacted by phone for follow-up assessment.

The primary outcome was assessed using the Revised Scoliosis Research Society-22 (SRS-22r) questionnaire, a validated tool for evaluating post-operative QoL in scoliosis patients.^[8] This questionnaire includes 22 items categorized into five domains: physical function, pain, self-image, mental health, and satisfaction with treatment. Each item is rated on a 5-point Likert scale, where 1 represents the worst possible outcome and 5 represents the best possible outcome. The local version of the questionnaire was validated in prior studies and was used to ensure linguistic and cultural appropriateness.^[9]

All statistical analyses were performed using the Statistical Package for the Social Sciences version 23. The normality of data distribution was assessed using the Kolmogorov– Smirnov test. Descriptive statistics were reported as mean ± standard deviation for normally distributed continuous variables and median (interquartile range) for non-normally distributed variables. Categorical variables were presented as frequencies and percentages. Group comparisons were conducted using an independent t-test for normally distributed variables, a Mann–Whitney U-test for non-normally distributed variables, and a Chi-square or Fisher’s exact test for categorical variables. P < 0.05 was considered statistically significant.

RESULTS

A total of 102 patients were initially enrolled, including 70 with IS and 32 with CS. However, complete data were available for 81 patients: 56 in the IS group and 25 in the CS group [Table 1].

All surgeries were performed by the senior surgeon (F.O.K.) all these years using a posterior-only approach with pedicular screw and rod fixation. Patients were excluded due to death (n = 2), relocation (n = 1), refusal to participate (n = 2), or loss of follow-up due to changed contact information (n = 16). The mean patient’s age at the time of surgery and follow-up duration were not significantly different between the IS and CS groups. However, a statistically significant difference in sex distribution was observed.

Overall, the patients with IS reported significantly higher scores in self-image (P = 0.023), mental health (P = 0.015), and total score (P = 0.022) compared to the CS group [Table 2]. No significant differences were found in physical function, pain, satisfaction, or subtotal scores excluding satisfaction between the two groups (P > 0.05).

Sex-specific analyses revealed no significant differences among male patients in any domain. However, among female patients, IS patients reported significantly higher scores in self-image (P = 0.011), mental health (P = 0.011), subtotal score (excluding satisfaction; P = 0.011), and total score (P = 0.011) compared to those with CS. This suggests a better perceived QoL and outcomes among females with IS.

DISCUSSION

In the present study, we compared the long-term outcomes following surgical correction of IS and CS, focusing on QoL, functional outcomes, pain, psychological aspects, and patient satisfaction. Our findings indicate substantial improvements in both patient groups, demonstrating the overall efficacy of surgical interventions. Nonetheless, notable differences emerged in psychological outcomes, particularly in self-image and mental health domains, with IS patients reporting significantly better outcomes compared to CS patients, especially among females.

The mean patient age at the time of surgery was approximately 15 years in both patient groups, aligning closely with findings from previous studies. For instance, Heemskerk et al.^[5] reported mean ages of around 15 years for both IS and CS patients undergoing surgical correction. This consistent age profile likely reflects established clinical practices favoring surgical intervention during adolescence, a critical period for spinal correction due to skeletal maturity and optimal potential for successful spinal fusion and deformity correction. In contrast, some European studies, such as Simony et al.^[10] in Denmark, reported slightly older ages at surgical intervention, potentially reflecting different clinical practices, healthcare access, or patient referral patterns.

Regarding functional outcomes, no statistically significant differences between IS and CS groups were observed in our study, which aligns well with the existing literature. Vigneswaran et al.^[11] evaluated over 20,000 cases of IS, and similarly documented satisfactory functional outcomes in most patients, though a subset reported persistent limitations and chronic pain postoperatively. In agreement, Tsirikos and García-Martínez demonstrated that CS patients generally achieve a functional status comparable to normative populations over long-term follow-up, despite reporting a higher prevalence of chronic pain and reduced muscle strength in certain cases.^[12] These parallel findings across multiple studies underscore the general effectiveness of surgical intervention in preserving functional capacities in scoliosis patients, irrespective of etiology.

A particularly notable outcome of our study was the disparity in psychological outcomes between the IS and CS groups. Specifically, IS patients reported significantly superior self-image and mental health scores, predominantly among females. This finding resonates strongly with previous research. Zeynalov and Burtsev reported greater psychological challenges among CS patients following surgery, attributing these to more pronounced physical deformities and resultant impacts on self-perception and social interactions.^[13] Similarly, Weiss et al.^[14] reported a significant rate of anxiety and self-esteem issues in postoperative CS patients.^[14] Such consistent findings across studies highlight the critical need for targeted psychological interventions and counseling pre- and postoperatively, particularly among CS patients who face more significant psychosocial burdens related to deformity severity.

Our analysis revealed no significant differences in patient satisfaction between groups, with high satisfaction rates in both IS and CS patients. This aligns with long-term postoperative follow-ups, such as those studies conducted by Simony et al.^[10] and Elashmawy et al.,^[15] suggest that satisfaction may depend more on patient expectations, comprehensive pre-operative counseling, and the presence of structured support, rather than solely on objective clinical outcomes. Effective communication of realistic expectations regarding post-operative outcomes and potential limitations remains essential to maintaining high satisfaction rates.

The sex differences observed in our study further underscore important considerations in patient management. Female patients with CS exhibited significantly poorer self-image and mental health outcomes compared to their IS counterparts. This finding aligns with Farshad et al., who emphasized heightened sensitivity to aesthetic outcomes among female scoliosis patients, which significantly influences psychological well-being post-surgery.^[16] Recognizing these sex-specific differences highlights the importance of incorporating sex-sensitive counseling and post-operative psychological support tailored specifically to the patient’s concerns.

This study possesses several strengths, notably the direct comparative analysis between the IS and CS groups and the comprehensive long-term follow-up. Furthermore, employing the validated Persian SRS-22r questionnaire enhanced our findings’ reliability and cultural applicability. Despite these strengths, some limitations must be acknowledged. First, the retrospective and cross-sectional nature of the study may introduce recall bias, particularly given the telephonic data collection method. In addition, the absence of detailed data on pre-operative curve severity and small sample size may limit the depth of subgroup analyses and interpretations. Future research should aim for prospective, longitudinal designs that incorporate detailed clinical, radiological, and surgical data. Such designs would facilitate a deeper understanding of factors affecting long-term post-operative outcomes. Comprehensive follow-up should include repeated functional assessments, imaging-based evaluations, and structured psychological evaluations to track postoperative changes systematically.

CONCLUSION

This study provides valuable evidence affirming the long-term efficacy of surgical correction in improving QoL, functionality, and patient satisfaction for both idiopathic and CS patients. Nevertheless, significant psychological challenges remain prominent among CS patients, particularly females.