Abstract
Background
This study aims to evaluate the long-term outcomes of one-stage posterior hemivertebra resection and short segment fusion with pedicle screw fixation in children with thoracolumbar congenital early-onset scoliosis (TLCEOS). It specifically investigates the durability of spinal correction and the incidence of complications over an average follow-up of 8.97 years.
Methods
A retrospective review was conducted on 32 patients treated at a tertiary scoliosis referral center from April 2003 to December 2019. Inclusion criteria were thoracolumbar hemivertebra (T11-L1), treatment via posterior hemivertebra resection and short segment fusion (≤ 5 segments), age under 10 years at surgery, and a follow-up of at least 5 years. Exclusions included idiopathic, syndromic, or neuromuscular scoliosis. Data on demographics, surgical procedures, and radiographic outcomes were collected, and clinical outcomes were evaluated using the Scoliosis Research Society-22 (SRS-22) questionnaire. Statistical analysis was performed using SPSS and R software.
Results
The study included 32 patients (22 males, 10 females) with a mean age of 5.00 ± 2.42 years at surgery and an average follow-up of 8.97 ± 2.81 years. On average, 3.47 ± 1.11 segments were fused. The main curve corrected from 38.64° ± 14.12° preoperatively to 9.06° ± 7.29° postoperatively, with a final correction rate of 61%. Significant improvements were observed in the SRS-22 domains of Appearance and Satisfaction with Treatment. There were 17 complications, including neurological, pulmonary, and mechanical issues, with some cases requiring revision surgery.
Conclusions
One-stage posterior hemivertebra resection and short segment fusion with pedicle screw fixation effectively correct TLCEOS long-term, offering significant improvements in patient appearance and satisfaction, with a manageable complication profile.
Keywords: Congenital early-onset scoliosis, Thoracolumbar hemivertebra, Hemivertebra resection, Spinal deformity correction, Long-term outcomes
Background
Congenital scoliosis (CS), a spinal deformity resulting from anomalous vertebral development in utero, presents significant challenges in pediatric orthopedics. Early-onset scoliosis (EOS) is defined as a form of scoliosis that manifests before the age of 10, CS is one of the most prevalent EOS. Among the various types of CS, thoracolumbar congenital early-onset scoliosis (TLCEOS) is particularly notable for its rapid progression during growth spurts, which necessitates timely and effective intervention to prevent severe spinal deformity and associated complications [1].
Hemivertebra, a common cause of CS, represents a failure in the segmentation or formation of vertebrae, leading to a wedge-shaped deformity. The natural history of untreated hemivertebra can result in progressive spinal deformity as the child grows, often necessitating surgical intervention [2]. According to Bollini G's report, thoracolumbar hemivertebra exhibits unique behavior, with scoliosis or kyphosis in the thoracolumbar region worsening more rapidly [3].
Posterior hemivertebra resection, combined with short segment fusion using pedicle screw fixation, has been advocated as an effective surgical treatment for achieving spinal balance and preventing curve progression in CS [4, 5].
Posterior thoracolumbar hemivertebra resection with short-segment fusion achieves satisfactory deformity correction and robust fixation, with significantly shorter operative times and fewer complications compared to other surgical methods [6].
Previous studies on hemivertebra resection often lack detailed reporting on the hemivertebra location [1], do not focus specifically on CEOS [7], or have short follow-up periods [8, 9], and often do not include comprehensive assessment of clinical outcomes. Overall, there is a scarcity of long-term follow-up data and assessment of clinical outcomes for this surgical approach. The primary objective of this study is to evaluate the long-term outcomes, with an average follow-up period of 8.97 ± 2.81 years, including the maintenance of spinal correction, assessment of clinical outcomes and the incidence of complications, in a cohort of children who underwent one-stage posterior hemivertebra resection and short segment fusion with pedicle screw fixation for TLCEOS.
Methods
Study design and patients
This retrospective study was conducted at a tertiary scoliosis referral center and involved 32 patients treated at our institution from April 2003 to December 2019. Eligibility criteria included a diagnosis of thoracolumbar hemivertebra (T11-L1), treatment with posterior hemivertebra resection and short segmental fusion (≤ 5 segments), age at surgery under 10 years, and a minimum follow-up period of 5 years to evaluate clinical outcomes. Patients with idiopathic, syndromic, or neuromuscular scoliosis were excluded. All surgeries were performed by the same spinal deformity surgeon with over 20 years of experience at the same institution to maintain consistency in surgical techniques and postoperative management.
Patient demographics and radiographic evaluation
We performed a retrospective review of electronic patient records and radiographic data from our database, collecting demographic and surgical information, including age, gender, follow-up duration, hemivertebra type, spinal scoliosis type, location of hemivertebra, fusion segments, estimated blood loss, and operation time.
Radiographic parameters were evaluated at each follow-up visit using Surgimap Software (Nemaris Co., USA). The parameters assessed included the main curve, compensatory curve, lumbar lordosis (LL), coronal balance (CB), sagittal balance (SB), apical vertebral translation (AVT), segmental kyphosis (SK), thoracic kyphosis (TK). CB was determined by measuring the deviation of the C7 plumb line from the center sacral vertical line. SB was measured as the distance from the C7 plumb line to a perpendicular line from the posterosuperior corner of the sacrum. Deviations were labeled positive ( +) when the C7 plumb line was anterior and negative ( −) when posterior to this point. SK was measured between the upper endplate above and the lower endplate below the hemivertebra. LL was assessed from the upper endplate of T12 to the upper endplate of the sacrum, while TK was measured from the upper endplate of T5 to the lower endplate of T12.
Adding-on deformity was identified by a progression in the Cobb angle of the adjacent vertebra by more than 10° during follow-up in the absence of other causes. The crankshaft phenomenon was defined as a change in the Cobb angle or Rib Vertebral Angle Difference (RVAD) of 10° or more from baseline to the last follow-up. Proximal junctional kyphosis (PJK) was defined as a sagittal Cobb angle increase of over 10° in the proximal junctional region, measured between the lower endplate of the upper instrumented vertebra and the upper endplate of the vertebra two levels above, compared to the preoperative angle.
All de-identified radiographs were independently and blindly evaluated by trained attending spinal surgeons.
Surgical details
All patients underwent single-stage posterior hemivertebra resection with pedicle screw fixation, supplemented with cross-links when necessary to enhance immediate postoperative stability. After anesthesia, patients were positioned prone, and standard disinfection and draping procedures were performed. Subperiosteal dissection was carried out for the segments requiring fusion while preserving the integrity of the supraspinous ligament and joint capsules at both ends. Under fluoroscopic guidance, guide pins were placed in the hemivertebra and adjacent pedicles for precise localization, followed by pedicle screw insertion according to preoperative plans.
The posterior elements, including the spinous process, lamina, facets, and transverse processes of the hemivertebra, were excised. Care was taken to dissect and protect the spinal cord and nerve roots above and below the hemivertebra. A bone chisel was used to excise one side of the vertebral body along the pedicle margins while preserving the anterior longitudinal ligament and completely removing the adjacent intervertebral discs to expose the bleeding bony endplates. Thin residual bone layers anterior to the dura were managed under direct vision by either pushing them forward or removing them.
Pedicle screws on both sides were connected to pre-bent titanium rods (4.5 mm), and alternating compression and distraction were applied for correction. For large hemivertebrae where the osteotomy gap could not be closed completely or significant kyphosis was present, a titanium cage filled with autologous bone was used for anterior column reconstruction, followed by compression to secure the cage and correct kyphosis. For smaller hemivertebrae without significant kyphosis, absorbable bone substitutes were used to graft the osteotomy gap, ensuring adequate filling and complete closure. The laminae and facet joints of the fusion segments were decorticated, and a graft using morselized autologous bone or, if necessary, mixed with allograft, was performed following Moe’s technique. Controlled hypotension was maintained intraoperatively to minimize bleeding, and all procedures were performed under continuous spinal cord monitoring.
Postoperative management
Postoperatively, a wound drainage tube was left in place and removed within 72 h, allowing patients to start mobilization. Custom protective braces were fitted in the standing position. Infants and those unable to comply with therapy were advised to wear the brace continuously for three months, then during mobilization for another three months. Other children wore the brace only while mobile for three months.
Assessment of clinical outcomes and complications
Clinical outcomes were assessed preoperatively, at 6 months postoperatively, and during the last follow-up using the SRS-22 questionnaire. Due to the young age of the patients, they were unable to complete the SRS-22 questionnaire themselves; therefore, all assessments were completed by the patients' parents. Complications were documented utilizing an adapted version of the classification system proposed by Klineberg et al. [10]. Data on total complications, surgical-related complications, mechanical-related complications, unplanned revisions, and their respective management strategies were recorded.
Statistical analysis
Data analysis was conducted using SPSS for Mac (version 27.0.1; IBM) and R for Mac (version 4.4.0; R Foundation for Statistical Computing). Continuous variables were expressed as mean (standard deviation), while categorical variables were reported as frequencies (percentages). The normality of continuous variables was assessed; Student’s t-test was employed for normally distributed data, and the Mann–Whitney U test was applied for non-normal distributions. A significance level of p < 0.05 was used for all statistical tests.
Results
Demographic and surgical data
In this study, a total of 32 patients were included, comprising 22 males (68.8%) and 10 females (31.3%), with a mean age of 5.00 ± 2.42 years at the time of surgery. The follow-up duration averaged 8.97 ± 2.81 years. Regarding hemivertebra type, 20 patients (62.5%) had fully segmented hemivertebrae, while 12 (37.5%) presented with semi-segmented hemivertebrae. Spinal deformity was categorized into scoliosis for 11 patients (34.4%) and kyphoscoliosis for 21 patients (65.6%). Surgical intervention typically involved fusion of multiple vertebral segments, with an average of 3.47 ± 1.11 segments fused. The estimated blood loss during surgery was 310.63 ± 168.71 ml, and the mean operative time was 182.66 ± 53.59 min (Table 1).
Table 1.
Characteristics and surgical data
| Characteristic | N = 32a |
|---|---|
| Age (years) | 5.00 (2.42) |
| Gender | |
| Female | 10 (31.3%) |
| Male | 22 (68.8%) |
| Follow-up duration (years) | 8.97 (2.81) |
| Hemivertebra type | |
| Fully segmented | 20 (62.5%) |
| Semi-segmented | 12 (37.5%) |
| Spinal scoliosis type | |
| Scoliosis | 11 (34.4%) |
| Kyphoscoliosis | 21 (65.6%) |
| Fusion segments | 3.47 (1.11) |
| Estimated Blood loss (ml) | 310.63 (168.71) |
| Operation time (min) | 182.66 (53.59) |
aMean (SD); n (%)
Deformity correction
The main curve had an average preoperative angle of 38.64° ± 14.12°. Postoperatively, this angle decreased significantly to 9.06° ± 7.29°, achieving a 77% correction rate (P < 0.001) with an initial mean difference of 29.58° (95% CI: 25.05 to 34.10). At the last follow-up, the angle slightly increased to 14.77° ± 12.28°, corresponding to a final correction rate of 61% (P < 0.001), with a final mean difference of 23.87° (95% CI: 18.66 to 29.08). Preoperatively, the compensatory cranial curve measured 13.28° ± 8.03°. It improved to 5.33° ± 6.14° immediately postoperatively, showing a 58% correction rate (P < 0.001), with an initial mean difference of 7.95° (95% CI: 5.57 to 10.33). At the last follow-up, this angle increased to 11.79° ± 10.63°, with a non-significant final mean difference of 1.49° (95% CI: -1.93 to 4.91) and a negative correction rate of -14% (P = 0.179). The compensatory caudal curve had a preoperative average angle of 13.34° ± 7.56°. This was corrected to 4.03° ± 3.28° postoperatively, achieving a 55% correction rate (P < 0.001) and an initial mean difference of 9.31° (95% CI: 6.52 to 12.10). By the last follow-up, the angle increased to 7.00° ± 5.45°, with a final mean difference of 6.34° (95% CI: 3.73 to 8.96) and a correction rate of 25% (P < 0.001) (Table 2).
Table 2.
Main curve and compensatory curve
| Variable | Preoperativea | IMPOa | Initial mean difference (95%CI)b | Initial correction ratea | Last Follow upa | Final mean difference (95%CI)c | Final correct ion ratea |
|---|---|---|---|---|---|---|---|
| Main curve (°) | 38.64 (14.12) | 9.06 (7.29) | 29.58 (25.05 to 34.10) | 77% (17%) | 14.77 (12.28) | 23.87 (18.66 to 29.08) | 61% (30%) |
| Compensatory cranial curve (°) | 13.28 (8.03) | 5.33 (6.14) | 7.95 (5.57 to 10.33) | 58% (29%) | 11.79 (10.63) | 1.49 (-1.93 to 4.91) | -14% (150%) |
| Compensatory caudal curve (°) | 13.34 (7.56) | 4.03 (3.28) | 9.31 (6.52 to 12.10) | 55% (69%) | 7.00 (5.45) | 6.34 (3.73 to 8.96) | 25% (134%) |
IMPO indicates immediate postoperative
Initial mean difference (95%CI) refers to comparison between Preoperative and IMPO
Final difference (95%CI) refers to comparison between Preoperative and Last Follow up
P < 0.05
aMean (SD)
bSignificantly changed between Preoperative and IMPO
cSignificantly changed between Preoperative and Last Follow up
Apical vertebral translation, coronal and sagittal balance
The preoperative apical vertebral translation (AVT) was measured at 24.47 mm ± 15.28 mm. Immediately following surgery, the AVT improved to 9.14 mm ± 8.04 mm, showing a significant reduction. At the last follow-up, the AVT was 15.55 mm ± 16.69 mm. This represents a substantial and statistically significant improvement compared to the preoperative values. The preoperative CB was 13.81 mm ± 10.05 mm. It improved to 10.58 mm ± 8.91 mm immediately postoperatively and further to 8.68 mm ± 10.86 mm at the last follow-up. Despite these improvements, the changes were not statistically significant, with a final mean difference of 5.12 mm (95% CI: -0.28 to 10.54, P = 0.062) compared to preoperative values. The SB was initially 0.95 mm ± 16.55 mm before surgery. Postoperatively, it slightly increased to 3.45 mm ± 14.02 mm but then adjusted to 2.59 mm ± 13.98 mm at the last follow-up. These changes were also not statistically significant, with a final mean difference of -1.64 mm (95% CI: -9.44 to 6.15, P = 0.670) compared to preoperative measurements (Table 3).
Table 3.
Coronal and sagittal balance
| Variable | Preoperative1 | IMPO1 | Initial mean difference (95%CI) | P value2 | Last follow up1 | Final mean difference (95%CI) | P value2 |
|---|---|---|---|---|---|---|---|
| Apical vertebral translation (mm) | 24.47 (15.82) | 9.14 (8.04) | 15.33 (10.29 to 20.37) | < 0.001* | 15.55 (16.69) | 8.92 (2.90 to 14.94) | 0.005# |
| Coronal balance (mm) | 13.81 (10.05) | 10.58 (8.91) | 3.23 (-0.32 to 6.77) | 0.073 | 8.68 (10.86) | 5.12 (-0.28 to 10.54) | 0.062 |
| Sagittal balance (mm) | 0.95 (16.55) | 3.45 (14.02) | -2.51 (-9.89 to 4.87) | 0.493 | 2.59 (13.98) | -1.64 (-9.44 to 6.15) | 0.670 |
| Segmental kyphosis (°) | 19.01 (14.32) | 6.98 (6.77) | 12.04 (8.51 to 15.56) | < 0.001* | 9.38 (9.25) | 9.64 (5.70 to 13.57) | < 0.001# |
| Thoracic kyphosis (°) | 24.85 (12.95) | 22.32 (11.11) | 2.53 (-1.39 to 6.45) | 0.198 | 28.53 (14.60) | -3.68 (-9.45 to 2.08) | 0.202 |
| Lumbar lordosis (°) | 45.91 (17.47) | 38.60 (13.34) | 7.31 (1.81to 12.81) | 0.011* | 46.48 (16.04) | -0.57 (-6.97 to 5.84) | 0.857 |
IMPO indicates immediate postoperative
Initial mean difference (95%CI) refers to comparison between Preoperative and IMPO
Final difference (95%CI) refers to comparison between Preoperative and Last Follow up
*Significantly changed between Preoperative and IMPO
#Significantly changed between Preoperative and Last Follow up
1Mean (SD)
2Paired t-test
P < 0.05
Sagittal Plane (SK, TK, and LL)
The SK averaged 19.01° ± 14.32° preoperatively. It significantly decreased to 6.98° ± 6.77° immediately postoperatively and slightly increased to 9.38° ± 9.25° at the last follow-up. The mean correction of SK was significant, with a final difference of 9.64° (95% CI: 5.70 to 13.57, P < 0.001). Initially, TK was 24.85° ± 12.95°. It decreased slightly to 22.32° ± 11.11° postoperatively but increased to 28.53° ± 14.60° at the last follow-up. These changes were not statistically significant, with a final mean difference of -3.68° (95% CI: -9.45 to 2.08, P = 0.202). The LL averaged 45.91° ± 17.47° preoperatively. It decreased to 38.60° ± 13.34° immediately after surgery and then adjusted to 46.48° ± 16.04° at the last follow-up. The initial postoperative decrease was significant, with a mean difference of 7.31° (95% CI: 1.81 to 12.81, P = 0.011), but the final difference of -0.57° (95% CI: -6.97 to 5.84, P = 0.857) indicated a return to near preoperative values (Table 3).
Clinical outcomes
In evaluating the clinical outcomes using the SRS-22 questionnaire, significant improvements were observed in several domains following the one-stage posterior hemivertebra resection and short segment fusion with pedicle screw fixation. The Appearance scores showed a substantial increase from a mean preoperative value of 3.4 ± 0.4 to 4.2 ± 0.7 at 6 months postoperative, and further to 4.4 ± 0.3 at the last follow-up, with both changes being statistically significant (p < 0.001). Similarly, the Satisfaction with Treatment scores improved significantly from 3.5 ± 0.6 preoperatively to 4.5 ± 0.3 at 6 months postoperative and to 4.7 ± 0.2 at the last follow-up (p < 0.001). These results indicate that patients experienced notable enhancements in their perception of appearance and satisfaction with the surgical treatment over the long term. However, the domains of Function, Pain, and Mental Health did not show significant changes over the same periods. The Function scores slightly increased from 4.4 ± 0.6 preoperatively to 4.5 ± 0.5 at 6 months and remained at 4.5 ± 0.7 at the last follow-up (p > 0.05). Pain scores remained stable, with no significant difference between the preoperative mean of 4.7 ± 0.5 and the postoperative means at 6 months (4.7 ± 0.6) and at the last follow-up (4.8 ± 0.6) (p > 0.05). Mental Health scores also showed no significant variation, staying around 4.7 to 4.8 across all time points (p > 0.05). Overall, the total SRS-22 scores significantly improved from 4.0 ± 0.4 preoperatively to 4.6 ± 0.3 at 6 months postoperative and to 4.7 ± 0.5 at the last follow-up (p < 0.001), reflecting a comprehensive enhancement in patients' perceived quality of life following surgery (Table 4).
Table 4.
SRS-22 scores
| SRS-22 domains | Preoperative1 | Postoperative 6 months1 | P value2 | Last follow-up1 | P value2 |
|---|---|---|---|---|---|
| Function | 4.4 (0.6) | 4.5 (0.5) | 0.391 | 4.5 (0.7) | 0.393 |
| Pain | 4.7 (0.5) | 4.7 (0.6) | 1.002 | 4.8 (0.6) | 0.106 |
| Appearance | 3.4 (0.4) | 4.2 (0.7) | < 0.001* | 4.4 (0.3) | < 0.001# |
| Mental health | 4.7 (0.5) | 4.8 (0.4) | 0.376 | 4.8 (0.5) | 0.342 |
| Satisfaction with treatment | 3.5 (0.6) | 4.5 (0.3) | < 0.001* | 4.7 (0.2) | < 0.001# |
| SRS total | 4.0 (0.4) | 4.6 (0.3) | < 0.001* | 4.7 (0.5) | < 0.001# |
SRS-22 Scoliosis Research Society-22
*Significantly changed between Postoperative 6 months and Preoperative
#Significantly changed between Last follow-up and Preoperative
1Mean (SD)
2Paired t-test
P < 0.05
Complications
Of the 32 patients in our study, a total of 17 complications were recorded. Neurological complications occurred in one patient during surgery, marked by a 30% decrease in somatosensory evoked potential (SEP) and motor evoked potential (MEP) signals, which recovered upon cessation of the procedure. Pulmonary complications were observed in two patients: one with a respiratory tract infection treated with antimicrobial therapy and another with a right pleural effusion resolved through ultrasound-guided thoracentesis. In terms of mechanical complications, screw cutout was noted in one patient, necessitating revision surgery and removal of the internal fixation. The crankshaft phenomenon was observed in eight patients, with one requiring revision surgery and the remaining seven managed through observation. Additionally, adding-on occurred in three patients, with one undergoing revision surgery and two managed conservatively. PJK was recorded in two patients, one of whom underwent revision surgery, while the other was followed up for observation (Table 5).
Table 5.
Complications
| Complications | Numbers | Deal with |
|---|---|---|
| Total Complications | 17 | |
| Neurological complications | 1 | During surgery, there was a decrease of approximately 30% in somatosensory evoked potential (SEP) and motor evoked potential (MEP) signals, which recovered upon cessation of the procedure |
| Pulmonary complications | 2 | One case with a respiratory tract infection treated with antimicrobial therapy, another case with a right pleural effusion resolved through ultrasoundguided thoracentesis |
| Screw cutout | 1 | Revision surgery and removal of internal fixation |
| Crankshaft phenomenon | 8 | 1 case underwent revision surgery, 7 cases followed up for observation |
| Adding-on | 3 | 1 case underwent revision surgery, 2 cases followed up for observation |
| Proximal junctional kyphosis | 2 | One case underwent revision surgery, another case followed up for observation |
Discussion
Previous studies have extensively documented the natural progression of CS [11]. The severity of the deformity largely depends on the type and location of the hemivertebra. Complete or partially segmented hemivertebrae often lead to inevitable curve progression [12]. Hemivertebrae situated in the thoracolumbar region are particularly prone to worsening spinal curvature, which often necessitates early surgical intervention [13]. Early surgery in young children can prevent severe localized deformities and secondary structural curves, allowing the unaffected segments of the spine to grow normally [14]. Although the optimal timing for surgery remains uncertain, literature reports favorable outcomes in children under 10 years with congenital scoliosis [1, 9, 15], and even in children under 5 years [16, 17]. Our study included patients with a mean age of 5.00 ± 2.42 years at the time of surgery.
Previous literature reports correction rates for scoliosis and kyphosis after one-stage posterior hemivertebra resection of 55% to 86.1% and 60% to 85% [18], respectively. In our study, the average correction rate of the main curve was 77%, with a 61% correction maintained at the last follow-up, indicating sustained effectiveness of the surgical intervention in both the short and long term (Fig. 1). Although there was some regression in the correction rates of compensatory cranial and caudal curves during follow-up, a substantial degree of correction was retained overall. This may be due to the dynamic changes in the spine during growth, necessitating further long-term observation to evaluate clinical significance. These findings are consistent with the study by Beixi Bao et al. [7].
Fig. 1.
A 4-year-old boy with a kyphoscoliosis due to a right T11 fully segmented hemivertebra. a Preoperative posteroanterior standing radiograph at 4 years old showing thoracolumbar kyphoscoliosis and compensatory curves. b Preoperative lateral radiograph. c, d Preoperative 3-D CT reconstruction images. e Immediate postoperative posteroanterior standing radiograph. f Immediate postoperative lateral radiograph. The patient was treated with posterior hemivertebra resection of T11 and correction with T9-T12 posterior instrumentation and fusion. g Posteroanterior standing radiograph at 2 years postoperative. h Lateral radiograph at 2 years postoperative. i Posteroanterior standing radiograph at 4 years postoperative. j Lateral radiograph at 4 years postoperative. k Posteroanterior standing radiograph at the last follow-up, 6 years postoperative. l Lateral radiograph at the last follow-up, 6 years postoperative. These images show well-maintained correction and trunk balance over time
Postoperative assessments of coronal and sagittal balance demonstrated varying degrees of improvement, with overall trends indicating a positive impact on spinal alignment. Although some changes were not statistically significant, the significant correction of AVT highlights the procedure’s efficacy in addressing localized deformities. Specifically, the sustained postoperative improvement in SK (P < 0.001) suggests effective and lasting correction. In contrast, changes in TK and LL did not reach statistical significance, implying that while SK correction remains robust, the spine's natural adaptive mechanisms may mitigate long-term alterations in TK and LL. These findings are consistent with those reported by Chang et al. [1], reflecting similar long-term outcomes for this treatment.
Clinical outcomes assessed by the SRS-22 questionnaire demonstrated significant postoperative improvements. Notably, Appearance scores showed substantial enhancement from preoperative levels to both 6-month and last follow-up evaluations (p < 0.001). Satisfaction with Treatment scores also significantly increased postoperatively (p < 0.001), indicating marked improvements in patients' perceptions of their appearance and satisfaction with the surgical intervention over the long term. In contrast, no significant changes were observed in the domains of Function, Pain, and Mental Health during the same periods (p > 0.05). Overall, total SRS-22 scores improved significantly following surgery (p < 0.001), reflecting a comprehensive enhancement in perceived quality of life among patients. These results align closely with those reported by Zhuang et al. [19].
Despite the success of the surgical outcomes, postoperative complications remain a significant concern for this patient population. In our study, while no major vascular or neurological complications were observed, 25% of patients experienced crankshaft phenomena during follow-up. This complication rate aligns with findings by Bollini et al. [3], who reported a curve progression rate of 17.6% post-hemivertebra resection, and Terek et al. [20], who noted a 30% incidence in patients under 10 years with congenital scoliosis. Short-segment fusion can correct deformities and mitigate the impact on adjacent vertebral growth; however, excessively short fusion segments may result in curve progression postoperatively. Incomplete resection of the hemivertebra is also linked to the progression of the main curve. Congenital anomalies can lead to abnormal vertebral growth even after resection, affecting the structural differentiation of adjacent vertebrae. Therefore, a complete resection of the hemivertebra and appropriate selection of fusion segments are essential to prevent these complications.
In patients undergoing posterior hemivertebra resection, PJK remains a significant concern. Zhang et al. [21] reported a PJK incidence of 1.8% (1 out of 56 patients) following one-stage hemivertebra resection. Chen et al. [22] conducted a detailed study on PJK in infants with congenital scoliosis undergoing posterior hemivertebra resection and short fusion, finding a PJK rate of 10.3% primarily in thoracolumbar hemivertebra cases. In our study, PJK occurred in 6.3% of cases (2 out of 32), consistent with previous research findings. We identified unsatisfactory local correction, including inadequate correction of primary scoliosis and segmental lordosis, as major contributors to postoperative residual deformities. The subsequent increase in kyphotic and lordotic deformities during spinal growth poses a significant risk. We advocate preventive strategies reported in the literature, such as soft tissue protection, use of appropriately shaped rods, and postoperative bracing for at least six months to mitigate PJK [22, 23].
The occurrence of adding-on phenomenon is common in adolescent idiopathic scoliosis patients but can also occur postoperatively in congenital scoliosis. Chang et al. [1] first reported post-hemivertebra resection adding-on phenomenon in 11.1% of patients (2 out of 18) in 2015, and in 11.1% (5 out of 45) in 2016 [24]. In our study, the incidence of adding-on phenomenon was 9.4% (3 out of 32 patients), slightly lower than these previous reports, possibly influenced by the use of titanium mesh cages as anterior column support in some cases (Fig. 2).
Fig. 2.
A 7-year-old boy with a kyphoscoliosis due to left T11 and T12 fully segmented hemivertebrae. a Preoperative posteroanterior standing radiograph at 7 years old showing thoracolumbar kyphoscoliosis and compensatory curves. b Preoperative lateral radiograph. c, d Preoperative 3-D CT reconstruction images. e Immediate postoperative posteroanterior standing radiograph. f Immediate postoperative lateral radiograph. The patient underwent posterior resection of T11 and T12 hemivertebrae, with T10-L2 instrumentation and T11-L1 interbody fusion using a titanium cage. g Posteroanterior standing radiograph at 2 years postoperative. h Lateral radiograph at 2 years postoperative. i Posteroanterior standing radiograph at 4 years postoperative. j Lateral radiograph at 4 years postoperative. k Posteroanterior standing radiograph at the last follow-up, 6 years postoperative. l Lateral radiograph at the last follow-up, 6 years postoperative. These images show sustained correction and maintenance of trunk balance over time
The study's large cohort size is a notable strength, enabling robust statistical analysis and enhancing the reliability and generalizability of results. This allows for more precise identification of correlations and subtle differences. The homogeneity of the cohort, focusing solely on cases of thoracolumbar congenital early-onset scoliosis (TLCEOS) treated with hemivertebra resection and short segment fusion, further strengthens the study by reducing variability. Including clinical outcomes underscores the importance of appearance in patient satisfaction. However, the study's retrospective nature presents a risk of data inaccuracies. Additionally, results are specific to TLCEOS and may not extend to lumbosacral or cervicothoracic hemivertebra cases due to differing anatomical and mechanical environments. The young age of patients also necessitated parent-reported SRS-22 questionnaires, potentially affecting the accuracy of clinical outcome assessments. Furthermore, the cases were not stratified by hemivertebra type, use of cages, or addition of cross-links, which limits the granularity of the analysis. Future studies will aim to provide more detailed subgroup analyses on these factors.
Conclusions
Single-stage posterior hemivertebra resection and short segment fusion using pedicle screws fixation represent a safe and effective approach for treating TLCEOS. The corrective efficacy is supported by radiographic measurements, and clinical outcomes are validated using the SRS-22 questionnaire. Long-term follow-up demonstrates sustained correction and high patient satisfaction. However, the surgical technique demands expertise, and postoperative complications such as crankshaft phenomenon, PJK, and adding-on pose significant concerns for both patients and surgeons.
Acknowledgements
We express our gratitude to all patients and their families for their participation in this study.
Abbreviations
- TLCEOS
Thoracolumbar congenital early-onset scoliosis
- SRS-22
Scoliosis Research Society-22
- CS
Congenital scoliosis
- EOS
Early-onset scoliosis
- CEOS
Congenital early-onset scoliosis
- LL
Lumbar lordosis
- CB
Coronal balance
- SB
Sagittal balance
- AVT
Apical vertebral translation
- SK
Segmental kyphosis
- TK
Thoracic kyphosis
- RVAD
Rib-vertebral angle difference
- PJK
Proximal junctional kyphosis
- SEP
Somatosensory evoked potential
- MEP
Motor evoked potential
Authors’ contributions
Jianguo Zhang conducted surgeries, designed the study, and critically revised the manuscript. Zhiming Peng and Shengru Wang performed data analysis, drafted the manuscript, and Yiwei Zhao and Haoran Zhang contributed to study design, manuscript drafting, and critical revisions. You Du and Xiangjie Yin were responsible for data collection and radiographic measurements. All authors reviewed and approved the final manuscript.
Funding
National Key Research and Development Program of China, 2023YFC2507700; National High Level Hospital Clinical Research Funding, 2022-PUMCH-D-004.
Data availability
The datasets generated and/or analyzed during the current study are not publicly available due to ongoing patient follow-up requirements. Raw data cannot be shared at this time but are available from the corresponding author upon reasonable request.
Declarations
Ethics approval and consent to participate
Informed consent was obtained from the patients' parents, and the study was approved by the Institutional Review Board of Peking Union Medical College Hospital. The study adhered to the ethical standards of the 1964 Declaration of Helsinki and its subsequent amendments.
Consent for publication
Parental written informed consent was obtained for the publication of patient images.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Contributor Information
Shengru Wang, Email: wangshengru@foxmail.com.
Jianguo Zhang, Email: jgzhang_pumch@yahoo.com.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated and/or analyzed during the current study are not publicly available due to ongoing patient follow-up requirements. Raw data cannot be shared at this time but are available from the corresponding author upon reasonable request.