Clinical results and surgery tactics of spinal osteotomy for ankylosing spondylitis kyphosis: experience of 428 patients

An effective strategy for treatment of severe kyphosis secondary to ankylosing spondylitis: one-level modified osteotomy combined with shoulders lifting correction method

BACKGROUND

Severe kyphosis is a common condition in patients with advanced ankylosing spondylitis (AS). Although two-level osteotomy may serve as a potential alternative, it is often associated with increased blood loss and elevated surgical risks. To date, the optimal treatment for the challenging condition remains unclear. This study aims to introduce an effective strategy for the treatment of severe kyphosis secondary to AS, using one-level modified osteotomy combined with shoulders lifting correction method.

METHODS

Seventy AS kyphosis who were treated with the strategy from 2012 to 2022, were reviewed retrospectively. All patients were followed up for a minimum duration of 2 years. Spinal and pelvic parameters were measured, including pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumber lordosis (LL), PI and LL mismatch (PI-LL), thoracic kyphosis, global kyphosis (GK), T1 pelvic angle (TPA), sagittal vertical axis (SVA), osteotomized vertebral angle (OVA), and chin-brow vertical angle (CBVA). Parameters of local osteotomized complex were measured and calculated, including the height of osteotomized complex and the length of spinal cord shortening. Clinical outcome was evaluated using Scoliosis Research Society-22 and Oswestry Disability Index scores.

RESULTS

Seventy patients with average age of 39.8 years were followed-up for 29.3 months. Average operation time was 373.5 min, and average blood loss was 751.0 ml. Postoperatively, sagittal balance was successfully restored. GK decreased from 90.6° to 35.6°, LL decreased from 8.0° to -35.1°, TPA decreased from 56.8° to 27.8°, and SVA decreased from 24.4 cm to 8.7 cm (P < 0.05). A harmonious and matched spinopelvic alignment was achieved. PT decreased from 37.2° to 26.3°, PI-LL decreased from 54.1° to 10.2°, and SS increased from 9.2° to 19.7°(P < 0.05). Horizontal vision was obtained with postoperative CBVA of 8.8°. Average OVA correction was up to 47.3°, and the spinal cord was shortened by 24.3 mm, with a shortening rate of 36.0%. All patients demonstrated a favorable clinical outcome. No permanent nerve damage, screw loosening, rod breakage and main vascular injury were observed. One case required revision surgery due to screw cap loosening and delayed union. Solid bone fusion was achieved in all other patients.

CONCLUSIONS

One-level modified osteotomy combined with shoulders lifting correction method is a safe and effective strategy for the treatment of severe AS kyphosis. This strategy offers a promising alternative for managing severe AS kyphosis, and may be particularly well-suited for individuals with concurrent osteoporosis.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Multilevel Pedicle Subtraction Osteotomy for Correction of Thoracolumbar Kyphosis in Ankylosing Spondylitis: Clinical Effect and Biomechanical Evaluation

OBJECTIVE

To compare the clinical outcomes and biomechanical characteristics of 1-, 2-, and 3-level pedicle subtraction osteotomy (PSO), and establish selection criteria based on preoperative radiographic parameters.

METHODS

Patients undergone PSO to treat ankylosing spondylitis from February 2009 to May 2019 in Sun Yat-sen Memorial Hospital of Sun Yat-sen University were enrolled. According to the quantity of osteotomy performed, the participants were divided into group A (1-level PSO, n = 24), group B (2-level PSO, n = 19), and group C (3-level PSO, n = 11). Clinical outcomes were assessed before surgery and at the final follow-up. Comparisons of the radiographic parameters and quality-of-life indicators were performed among and within these groups, and the selection criteria were established by regression. Finite element analysis was conducted to compare the biomechanical characteristics of the spine treated with different quantity of osteotomies under different working conditions.

RESULTS

Three-level PSO improved the sagittal parameters more significantly, but resulted in longer operative time and greater blood loss (p < 0.05). Greater stress was found in the proximal screws and proximal junction area of the vertebra in the model simulating 1-level PSO. Larger stress of screws and vertebra was observed at the distal end in the model simulating 3-level PSO.

CONCLUSION

Multilevel PSO works better for larger deformity correction than single-level PSO by allowing greater sagittal parameter correction and obtaining a better distribution of stress in the hardware construct, although with longer operation time and greater blood loss. Three-level osteotomy is recommended for the patients with preoperative of global kyphosis > 85.95°, T1 pelvic angle > 62.3°, sagittal vertical alignment > 299.55 mm, and pelvic tilt+ chin-brow vertical angle > 109.6°.

Long-term outcome evaluation in ankylosing spondylitis with high-angle thoracolumbar kyphotic deformity corrected by one-stage single-level pedicle subtraction osteotomy augmented with Ponte osteotomy: A case series

INTRODUCTION AND IMPORTANCE

A high-angle thoracolumbar kyphotic deformity (TLKD) may complicate surgical rectification of AS patients since one-stage two-level pedicle subtraction osteotomy (PSO), which provides high-angular correction, leads to excessive blood loss, neurological deficits and fixation failures. This case series presents the long-term results of one-stage single level PSO with Ponte osteotomy (PO) in the treatment of AS patients with high-angle TLKD.

CASE PRESENTATION

This case series presents two AS patients with high kyphotic angles (KAs) of 86.1o. We collected data retrospectively from our institution's database between 2019 and 2023. A sagittal axis imbalance was the only complaint initially, no neurological deficits or other problems. A PSO augmented by PO was performed with a decompression laminectomy. Intraoperative monitoring (IOM) during reduction was used to observe neurological deficits. Blood loss at the highest rate was 1000 cc. It corrected 57.8o of KA postoperatively without neurological deficits. We found consistent results over 36 months.

CLINICAL DISCUSSION

A thorough analytical approach may help diagnose AS. One-stage single-level PSO may correct high-angle TLKD in AS patients effectively. To achieve greater angular correction, PO, a less risky osteotomy, must be added. Decompression laminectomy is vital before osteotomy and IOM is crucial during reduction to prevent nerve injury. Even with two osteotomies, there was less blood loss than previously reported. These impressive long-term results call for further research.

CONCLUSION

Combined PSO and PO with IOM efficiently magnifies the angular correction without postoperative neurological deficits or excessive blood loss in AS patients with high-angle TLKD.

Clinical features and outcomes of spine surgery in patients with ankylosing spondylitis

OBJECTIVES

The study aimed to comprehend the clinical features and outcomes of surgical treatments for spinal disorders in patients with ankylosing spondylitis (AS).

METHODS

This retrospective study enrolled patients with AS who underwent spine surgery between 2000 and 2019 in our facility.

RESULTS

Thirteen patients with AS underwent spine surgeries. The mean age was 56.2 years, and the mean disease duration was 25.1 years at the time of surgery. Nine patients had vertebral fracture, two had kyphotic deformity, and two had myelopathy due to the spinal ligament ossification. Fracture cases included five patients with secondary pseudarthrosis/delayed palsy due to conservative treatment failure. Spinal fixation was performed in all patients. Pedicle subtraction osteotomy for kyphosis and laminectomy for myelopathy were also conducted. All patients improved after surgeries. One patient with kyphotic deformity underwent additional surgery of bilateral hip prosthesis, which resulted in better spine alignment. Four cases of perioperative complications were observed.

CONCLUSION

Myelopathy was newly found as the aetiology requiring surgery in patients with AS. This summarized case series could help physicians to identify patients with surgically treatable spinal disorders among patients with AS.

Mini-open Pedicle Subtraction Osteotomy versus Standard Posterior Approach for Ankylosing Spondylitis-related Spinal Kyphosis: A Comparative Study

OBJECTIVE

Surgical strategy for spinal kyphosis in patients with ankylosing spondylitis (AS) has been challenging. Pedicle subtraction osteotomy (PSO) through a minimally invasive (MI) approach has been developed with promising clinical outcomes. We aimed to compare the effectiveness and safety of PSO via an MI approach and a standard posterior approach (SPA) for treating AS-related spinal kyphosis.

METHODS

A total of 41 patients with AS-related spinal kyphosis who underwent PSO through an MI approach (MI surgery [MIS] group: n = 25) or SPA (SPA group: n = 16) between January 2015 and July 2020 were retrospectively included. Spinopelvic parameters were evaluated before the surgery, immediately after the surgery, and at the 2-year follow-up. Clinical data including operative time, estimated blood loss, blood transfusion, level of fusion, incision length, bed rest period, length of hospitalization, and surgical complications were compared between the two groups. The Scoliosis Research Society outcomes instrument-22 (SRS-22) was administered to assess patients' quality of life at the latest follow-up. Comparisons between the two groups were performed using independent sample t-test or Chi-square test.

RESULTS

Characteristics and baseline kyphosis of the two groups were matched. At the 2-year follow-up, in the MIS group, the average correction values of the sagittal vertical axis and global kyphosis (GK) were 9.5 cm and 44.3°, respectively. Compared with the SPA group, the MIS group had similar correction values and correction losses after surgery. No obvious differences were observed in any radiographic parameters, except for GK, immediately after surgery and at the 2-year follow-up between the two groups (p > 0.05). The MIS group had a significantly shorter operative time, lesser blood loss, lesser transfusion volume, shorter fusion level, and lesser time to mobilization than did the SPA group. Higher average functional activity scores of SRS-22 were obtained in the MIS group than in the SPA group.

CONCLUSION

Mini-open PSO may be an effective alternative to the SPA for treating AS-related spinal kyphosis, with comparable correction effect, lesser surgical trauma and faster recovery. This comparative study may provide valuable guidance for surgical decision-making and patient counseling.

Operative strategies for ankylosing spondylitis-related thoracolumbar kyphosis: focus on the cervical stiffness, coronal imbalance and hip involvement

BACKGROUND

Cervical stiffness, coronal imbalance and limited hip movement all play crucial roles in designing the corrective surgery for ankylosing spondylitis-related thoracolumbar kyphosis (AS-TLK). However, a comprehensive classification and tailored strategies for directing clinical work are lacking. This study aims to investigate the types and surgical strategies for AS-TLK that consider cervical stiffness, coronal imbalance and hip involvement as the key factors.

METHODS

25 consecutive AS-TLK patients were divided into three types according to their accompanying features: Type I: with a flexible cervical spine; Type IIA: with a stiff cervical spine; Type IIB: with coronal imbalance; Type IIC: with limited hip movement. Type III is the mixed type with at least two conditions of Type II. Individual strategies were given correspondingly. Spinal-pelvic-femoral parameters were measured, Scoliosis Research Society outcome instrument-22 (SRS-22) was used and complications were recorded and analysed.

RESULTS

All patients (Type I 10, Type II 8 and Type III 7) underwent surgery successfully. 13 cases with 16 complications were recorded and cured. The patients were followed up for 24-65 months with an average of 33.0 ± 9.6 months. Both the sagittal and coronal parameters were corrected and decreased significantly (all, p < 0.05). SRS-22 scores showed a satisfactory outcome.

CONCLUSION

Thoracolumbar kyphosis secondary to ankylosing spondylitis are complex and variable. Considering the factors of cervical stiffness, coronal imbalance and hip involvement assists in making decisions individually and achieving a desired surgical result.

Comparison of One-Level Osteotomy and Two-Level Osteotomy for Thoracolumbar Kyphotic Deformity in Ankylosing Spondylitis: A Systematic Review and Meta-Analysis

BACKGROUND

One- and two-level osteotomies have been used to treat thoracolumbar kyphosis in patients with ankylosing spondylitis (AS). However, the effectiveness and safety of the 2 methods have not been systematically compared, and few studies have reported on which method might be more suitable for treating AS.

METHODS

We performed a systematic literature search. All comparative studies of one- and two-level osteotomy for the treatment of thoracolumbar kyphosis caused by AS were included. Efficacy was determined by the radiographic outcomes, including global kyphosis, sagittal vertical axis, and lumbar lordosis and the Oswestry disability index. The complication rates were used to assess the safety. We analyzed the data using Review Manager software.

RESULTS

A total of 10 studies were included and used for the meta-analysis. We pooled the studies according to the type of data they had reported to evaluate the radiographic correction and incidence of complications. We found that two-level osteotomy provided advantages compared with one-level osteotomy for spinal correction, including global kyphosis and lumbar lordosis. However, the correction was dependent on the degree of preoperative kyphosis. In addition, we found no differences between the 2 groups in the correction of the sagittal vertical axis or improvement in the Oswestry disability index. However, we did find differences in the incidence of neural complications, dural tear, and operative site infection.

CONCLUSIONS

Our findings have shown that one-level osteotomy is safer than two-level osteotomy. For AS patients with nonsevere kyphosis, one-level osteotomy will be sufficient for spinal sequence correction and maintenance of balance, and two-level osteotomy will not be needed. For AS patients with severe kyphosis, two-level osteotomy can be recommended for better orthopedic effects; however, a careful surgical technique is required.

A novel technique of transpedicular opening-wedge osteotomy for treatment of rigid kyphosis in patients with ankylosing spondylitis

BACKGROUND

To investigate the effectiveness and feasibility of a novel vertebral osteotomy technique, transpedicular opening-wedge osteotomy (TOWO) was used to correct rigid thoracolumbar kyphotic deformities in patients with ankylosing spondylitis (AS).

METHODS

Eighteen AS patients underwent TOWO to correct rigid thoracolumbar kyphosis. Radiographic parameters were compared before surgery, 1 week after surgery and at the last follow-up. The SRS-22 questionnaire was given before surgery and at the last follow-up to evaluate clinical improvement. The operating time, estimated blood loss and complications were analyzed.

RESULTS

The mean operating time and estimated blood loss were 236 min and 595 ml, respectively. The mean preoperative sagittal vertical axis (SVA), thoracic kyphosis (TK), pelvic tilt (PT) and thoracolumbar kyphosis (TLK) were 158.97 mm, 51.24 mm, 43.63 mm and 41.74 mm, respectively, and decreased to 66.72 mm, 35.96 mm, 27.21 mm and 8.67 mm at the last follow-up. The mean preoperative lumbar lordosis (LL) and sacral slope (SS) were 8.30 ± 24.43 mm and 19.67 ± 9.40 mm, respectively, which increased to 38.23 mm and 28.13 mm at the last follow-up. The mean height of the anterior column of osteotomized vertebrae increased significantly from 25.17 mm preoperatively to 37.59 mm at the last follow, but the height of the middle column did not change significantly. SRS-22 scores were improved significantly at the last follow-up compared with preoperatively. Solid bone union was achieved in all patients after 12 months of follow-up, and no screw loosening, screw removal or rod breakage was noticed at the last follow-up.

CONCLUSIONS

TOWO could achieve satisfactory kyphosis correction by opening the anterior column instead of vertebral body decancellation and posterior column closing, thus simplifying the osteotomy procedure and improving surgical efficacy.

2022 French Society for Rheumatology (SFR) recommendations on the everyday management of patients with spondyloarthritis, including psoriatic arthritis

OBJECTIVE

Update the French Society for Rheumatology (SFR) recommendations on the everyday management of patients with spondyloarthritis, including psoriatic arthritis.

METHODS

Following standardized procedures, a systematic literature review was done by four supervised rheumatology residents based on questions defined by a task force of 16 attending rheumatologists. The findings were reviewed during three working meetings that culminated in each recommendation receiving a grade and the level of agreement among experts being determined.

RESULTS

Five general principles and 15 recommendations were developed. They take into account pharmacological and non-pharmacological measures along with treatment methods based on the dominant phenotype present (axial, articular, enthesitis/dactylitis) and the extra-articular manifestations (psoriasis, inflammatory bowel disease, uveitis). NSAIDs are the first-line pharmacological treatment in the various presentations. Conventional synthetic disease modifying antirheumatic drugs (csDMARDs) are not indicated in the axial and isolated entheseal forms. If the response to conventional treatment is not adequate, targeted therapies (biologics, synthetics) should be considered; the indications depend on the clinical phenotype and presence of extra-articular manifestations.

CONCLUSION

This update incorporates recent data (published since the prior update in 2018) and the predominant clinical phenotype concept. It aims to help physicians with the everyday management of patients affected by spondyloarthritis, including psoriatic arthritis.

The Sagittal Parameters and Efficacy of Pedicle Subtraction Osteotomy in Patients with Ankylosing Spondylitis and Kyphosis Under Different Lumbar Sagittal Morphologies

OBJECTIVE

This study aimed to compare the changes in sagittal parameters and the efficacy of pedicle subtraction osteotomy (PSO) in patients with ankylosing spondylitis (AS) and kyphosis under different lumbar sagittal morphologies and to explore the effect of sagittal morphology on the selection of PSO levels.

METHODS

A total of 24 patients with AS and thoracolumbar kyphosis (TK) who were admitted to the First Affiliated Hospital of Xinjiang Medical University between 2008 and 2019 were enrolled in this study. They were divided into two groups: a lumbar lordosis group (n = 14) and a lumbar kyphosis group (n = 10). Changes in sagittal parameters, lumbar Japanese Orthopaedic Association (JOA) scores, and visual analog scale (VAS) scores for lumbar pain before and after operation were compared between the two groups to evaluate postoperative efficacy.

RESULTS

The preoperative lumbar lordosis (LL) was -29.29 ± 5.40 (lordosis) and 13.50 ± 3.65 (kyphosis) (P < 0.01), and the preoperative sagittal vertical axis (SVA) was 171.35 ± 25.46 (lordosis) and 223.58 ± 21.87 (kyphosis) (P < 0.01). Preoperative global kyphosis (GK) was 75.71 ± 5.26 (lordosis) and 86.30 ± 10.32 (kyphosis) (P < 0.05). All patients in the lordosis group underwent PSO surgery at the twelfth thoracic vertebra (T12) or the first lumbar spinal vertebra (L1), while all patients in the kyphosis group underwent the surgery at the second or third lumbar spinal vertebra (L2 or L3). The differences in postoperative GK, LL, and SVA between the two groups were not significant (P > 0.05). The JOA scores of the two groups increased from 13.00 ± 0.83 (lordosis) and 11.30 ± 0.93 (kyphosis) before surgery to 21.00 ± 0.67 and 19.70 ± 0.60 after surgery (P < 0.05).

CONCLUSION

Preoperative lumbar sagittal morphology needs to be considered when selecting the optimal osteotomy plane. An osteotomy can achieve the greatest success in patients with lumbar kyphosis at L2/L3; for patients with lumbar lordosis, it can achieve satisfactory outcomes at T12/L1.

One-level mini-open pedicle subtraction osteotomy for treating spinal kyphosis in patients with ankylosing spondylitis

BACKGROUND

To report a mini-open pedicle subtraction osteotomy (PSO) technique, to summarize the 2-year follow-up results of 25 patients, and to describe a modified operating table which allows the osteotomy to be closed in a more controllable manner.

METHODS

We retrospectively reviewed the records of patients with AS who received one-level mini-open PSO between July 2015 and January 2018. The 25 patients with complete medical records and 2-year radiographic follow-up were included in the analysis. Estimated blood loss, operation time, incision length, complications, bed rest period, and length of hospitalization were extracted from the medical records and recorded.

RESULTS

The mean age of the 25 patients (22 males and 3 females) was 39.5 years. The average global kyphosis(GK) decreased from 70.2° before surgery to 22.3° after surgery; the average C7- sagittal vertical axis (C7-SVA) decreased from 15.5 cm before surgery to 5.1 cm after surgery; the average pelvic incidence(PT) decreased from 37.8° before surgery to 22.5° after surgery. The average length of the incision was 10.2 cm. The average surgical time was 263.0 min, the average estimated blood loss was 840.0 ml, and the average time to mobilization was 4.1 days.

CONCLUSIONS

The current report shows that one-level PSO can be performed through an incision of about 10 cm. The one-level mini-open PSO could be superior to traditional PSO surgery with respect to cosmetic outcomes. Further comparative studies are necessary to evaluate the current and conventional techniques.

Spontaneous intraoperative lumbar fracture leading to an unexpected correction in ankylosing spondylitis corrective surgery - a case report

Severe kyphotic deformity in patients with ankylosing spondylitis can be corrected surgically to achieve a better spinal alignment and an improved visual axis. Different surgical techniques are used today depending on the extent of ossification and the degree of kyphosis. It is well known that the underlying disease leads to distinct biomechanical changes of the spinal column causing an increased fracture risk especially in case of minor trauma. This includes manipulations during surgical procedures as well as during the required perioperative measures.

We present the case of a 45-year-old patient with severe global kyphotic deformity due to ankylosing spondylitis. During the elective corrective surgery (pedicle subtraction osteotomy at the level of L3) the patient sustained a spontaneous fracture at L2/3. This fortunately nondisplaced wedge-shaped fracture in the sense of a Smith-Peterson osteotomy led to a spontaneous correction of the kyphosis. The described unexpected event required a change in the surgical strategy. Correction could be achieved using a two-stage surgical procedure without further drawbacks for the patient.

This case report stresses the need of particular attention regarding the increased susceptibility of the spinal column in case of ankylosing spondylitis.

[Application of self-designed adjustable operation frame in treatment of severe kyphosis secondary to ankylosing spondylitis with posterior osteotomy]

OBJECTIVE

To introduce a self-designed adjustable operation frame and explore the feasibility and safety in the treatment of severe kyphosis secondary to ankylosing spondylitis with posterior osteotomy.

METHODS

Between March 2016 and May 2018, 7 cases of severe kyphosis secondary to ankylosing spondylitis were treated with posterior osteotomy using self-designed adjustable operation frame with prone position. There were 5 males and 2 females with an average age of 49.4 years (range, 40-55 years). The disease duration was 10-21 years (mean, 16.7 years). The apical vertebrae of kyphosis were located at T 11 in 2 cases, T 12 in 1 case, L 1 in 1 case, and L 2 in 3 cases. Among the 7 cases, 2 were classified as typeⅠ, 4 as type ⅡB, and 1 as type ⅢA according to 301 classification system. There was no neurological deficit of all cases; but 1 case suffered bilateral hip joints ankylosed in non-functional position. The parameters of chin-brow vertical angle (CBVA), global kyphosis (GK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sagittal vertical axis (SVA) were measured; and the operation time, the intraoperative blood loss, and the complications were also collected and analyzed.

RESULTS

All operations completed successfully. The operation time was 310-545 minutes (mean, 409.7 minutes) and the intraoperative blood loss was 1 500-2 500 mL (mean, 1 642.9 mL). There were 2 cases treated with one-level osteotomy of sagittal translation, 1 case of radiculopathy symptom of L 3, and 3 cases of tension of abdominal skin. All patients were followed up 20-35 months (mean, 27.9 months). There were significant differences in CBVA, GK, TLK, LL, and SVA between pre- and post-operation ( P<0.05); but no significant difference between 1 week after operation and last follow-up ( P>0.05). All the osteotomies and bone grafts fused well and no complications of loosening and breakage of internal fixator occurred during the follow-up.

CONCLUSION

In the posterior osteotomy for correction of severe kyphosis secondary to ankylosing spondylitis, the self-designed adjustable operation frame is convenient for the patient to be placed in prone position. It is safe, feasible, and effective to perform osteotomy correction with the aid of the self-designed adjustable operation frame.