A pedicle subtraction osteotomy as an adjunctive tool in the surgical treatment of a rigid thoracolumbar hyperkyphosis; a preliminary report

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.

Atypical Scheuermann's disease with severe kyphosis and negative sagittal balance in the thoracolumbar region: A case report and literature review

INTRODUCTION AND IMPORTANCE

Scheuermann's kyphosis is a structural deformity of the thoracolumbar spine that is classified in typical (thoracic) and atypical (lumbar and thoracolumbar) Scheuermann's disease. Surgical intervention is reserved for those with progressive kyphosis, intractable pain and neurological impairment. Although, previous literature focuses on the correction of the thoracic kyphosis (TK), recent lines of evidence recommend considering all the sagittal balance parameters when performing a surgery. We herein, report a posterior-only approach in a patient with Scheuermann's kyphosis, considering all the sagittal balance parameters.

CASE PRESENTATION

The patient was a 17-year-old boy with a kyphotic deformity in the lumbar region, with urinary retention and upper back intractable pain. The preoperative physical examination was normal except for a kyphotic gait. The patient was first treated with thoracic lumbosacral orthoses (TLSO) brace that was not effective; consequently, the patient underwent posterior only approach (pedicular screw fixation along with Smith-Peterson osteotomy) with correction of the sagittal balance and kyphosis. The patient's sign and symptoms improved significantly. The surgery was uneventful and no complication was recorded. The 1-year follow-up revealed normal neurological examination and normal sagittal balance parameters.

CLINICAL DISCUSSION

Atypical Scheuermann's kyphosis with neurological impairment and progressive kyphosis should be treated with surgical intervention.

CONCLUSION

Considering the sagittal parameters of the spine, the surgical intervention should be designed to correct the kyphosis and the other indices of the sagittal balance. Posterior-only approach is safe and effective method for correction of the TK and improving the signs and symptoms of the patients.

Pedicle subtraction osteotomy for the corrective surgery of ankylosing spondylitis with thoracolumbar kyphosis: experience with 38 patients

OBJECTIVE

To evaluate the sagittal parameters and clinical outcome of pedicle subtraction osteotomy (PSO) for the treatment of ankylosing spondylitis (AS) combined with thoracolumbar kyphosis.

METHODS

The clinical data of 38 patients with AS combined with thoracolumbar kyphosis who underwent PSO were enrolled and divided into the lumbar lordosis group and the lumbar kyphosis group according to the preoperative sagittal morphology. They were subdivided into the lumbar lordosis T12 group, lordosis L1 group, kyphosis L2 group, and kyphosis L3 group. The spine sagittal parameters were compared between the preoperative and the postoperative. Outcome evaluation was performed by the Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS), and the Oswestry Disability Index (ODI).

RESULTS

A total of 38 patients with AS combined with thoracolumbar kyphosis were successfully treated by PSO, with a mean follow-up time of 26.9 ± 11.9 months. There were 30 males and 8 females with a mean age of 41.6 ± 7.1 years. Twenty patients consisted in the lumbar lordosis group and 18 patients in the lumbar kyphosis group. GK, SVA, and CBVA were improved significantly (P < 0.05) at the final follow-up between the lumbar lordosis T12 group and the L1 group. Patients in the lumbar kyphosis L2 group and L3 group all received satisfactory, including LL, GK, and SVA (P < 0.05). There was no statistically significant difference in the preoperative TK, GK, SVA, PT, and PI between the lumbar lordosis and lumbar kyphosis groups (P > 0.05). Postoperative complications occurred in three cases.

CONCLUSION

PSO was a practical method for the treatment of patients with AS combined with thoracolumbar kyphosis. PSO at L3 was recommended to be selected for the lumbar kyphosis to obtain greater SVA correction. CBVA of single-segment PSO may be significantly lower than the two-segment PSO in the management of patients with kyphosis of lower CBVA.

Protection of L1 nerve roots by pre-relieve tension in parallel endplate osteotomy for severe rigid thoracolumbar spine deformity

BACKGROUND

This is a retrospective study of the use of parallel endplate osteotomy (PEO) for correction of severe rigid thoracolumbar spine deformity.

METHODS

From July 2016 to January 2019, 12 patients with severe rigid thoracolumbar spine deformity underwent PEO on T12 or L1 vertebrae were studied.

RESULTS

Following PEO at T12 or L1, the mean kyphosis and scoliosis correction rates reached 77.0 ± 8.9% and 75.5 ± 8.0%, respectively and the intraoperative estimated blood loss was 1950 ± 1050 mL, and the mean operative time was 6.98 ± 4.02 h. The SF-36 scores of physical function, role-physical, bodily pain, general health, vitality, social function, role-emotional and mental health changed from 63 ± 28, 50 ± 25, 50 ± 30, 34 ± 19, 53 ± 28, 45 ± 30, 30 ± 36 and 54 ± 18 at baseline to 83 ± 18, 69 ± 19, 72 ± 12, 66 ± 21, 75 ± 15, 72 ± 22, 66 ± 34 and 76 ± 12 at 1 year postoperatively, 83 ± 8, 68 ± 32, 83 ± 17, 73 ± 17, 82 ± 18, 76 ± 26, 70 ± 37 and 88 ± 12 at 18 months postoperatively, 86 ± 6, 83 ± 33, 90 ± 16, 81 ± 16, 89 ± 14, 88 ± 25, 83 ± 17 and 94 ± 10 at 24 months postoperatively, respectively (P < 0.01). Three patients had symptoms of L1 nerve root injury, as reflected by lower limb weakness and inner thigh numbness on knee extension and hip flexion, which was further confirmed by electromyography.

CONCLUSIONS

PEO is easier to operate, and the spinal cord and nerve root are under direct vision and can effectively and safely correct severe rigid thoracolumbar spine deformity with satisfactory clinical results. However, it is important to identify, separate and protect L1 nerve roots during surgery in cases where patients have symptoms of back pain, muscle weakness and leg numbness on the convex side after surgery.

PI and T9-SPI: New Predictive Factors for Increased Kyphosis of the Thoracolumbar Junction in Thoracolumbar/Lumbar Adolescent Idiopathic Scoliosis

Objectives: Studies have demonstrated that there is an increased thoracolumbar junction sagittal Cobb angle (TLJS) in thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) patients. The objectives were to ascertain the correlations between the spinopelvic alignments and TLJS and to explore potential predictive factors for hyperkyphotic TLJS in the sagittal plane in thoracolumbar/lumbar AIS. Methods: A total of 114 AIS patients with thoracolumbar/lumbar curve were included. Cobb angle, apical vertebrae rotation (AVR), thoracic kyphosis (TK), TLJS, lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), T1-spinopelvic inclination (T1-SPI), and T9-spinopelvic inclination (T9-SPI) were measured. After patients were organized into two subgroups based on TLJS, all parameters were compared between the two groups. Correlation analysis and multiple linear regression analysis were performed between the radiologic measurements and TLJS in all patients. Results: There was a significant difference between the non-kyphotic group and kyphotic group in mean Nash-Moe grade, TK, T9-SPI, PI, and SS. Correlation analysis showed that LL, PI, and SS were inversely associated with TLJS. TK, T9-SPI, and Nash-Moe grade were positively related to TLJS. The multiple linear regression analysis showed that TLJS could be predicted by the equation TLJS = -2.322 + 5.585 × Nash-Moe grade + 0.687 × T9-SPI - 0.208 × PI, with an adjusted R² of 0.410. Conclusion: TLJS was positively correlated with greater AVR in the coronal plane, greater T9-SPI in the sagittal plane and inversely associated with PI among patients with thoracolumbar/lumbar scoliosis. Spine surgeons should pay more attention to the degree of AVR, T9-SPI, and PI when dealing with thoracolumbar/lumbar scoliosis with thoracolumbar junction kyphosis.

Postoperative changes in sacropelvic junction in short-segment angular kyphosis versus Scheuermann kyphosis

PURPOSE

To comparatively evaluate the biomechanical alterations those occur in the sagittal plane of sacropelvic junction in angular kyphosis (AK) and Scheuermann kyphosis (SK) patients after surgery.

METHODS

The spine radiographs of 52 patients operated for short-segment AK (n = 20) or SK (n = 32) were studied. Main outcome measures were sacral slope, pelvic incidence, pelvic tilt, lumbar lordosis, and thoracic kyphosis angles.

RESULTS

In AK group, local and thoracic kyphosis angles, as well as lumbar lordosis angle, showed statistically significant reduction with surgery. Thoracic kyphosis and lumbar lordosis angles were reduced significantly in SK group. Postoperatively, there were significant differences between groups in lumbar lordosis, pelvic tilt angle, and sacral slope (p = 0.021, p = 0.001, and p = 0.027, respectively). Thoracic kyphosis angle and sacral slope were increased, and there was a remarkable correlation between thoracic kyphosis and lumbar lordosis values in the AK group.

CONCLUSIONS

The results of this study suggest that a significant sacropelvic improvement can be achieved by balanced sagittal vertical axis and T1 spinopelvic leading to a good sagittal alignment of spine in patients with AK and SK. Changes seen in morphological parameters after surgery may be closely related with baseline biomechanics and structure of the spine and pelvis. Therefore, further clinical and scientific trials are necessary both to elucidate the biomechanics, their clinical implications, and to develop new techniques and models for spine and pelvis surgery.

Mini-open pedicle subtraction osteotomy as a treatment for severe adult spinal deformities: case series with initial clinical and radiographic outcomes

OBJECTIVE Pedicle subtraction osteotomy (PSO) is a powerful but high-risk surgical technique for destabilizing the spine for deformity correction in both the sagittal and coronal planes. Numerous reports have demonstrated the benefits of this technique for realigning the spine in a physiological posture; however, the open surgical technique is associated with a high complication rate. In this report the authors review data obtained in a series of patients who underwent PSO through a less invasive approach. METHODS Sixteen patients with severe coronal- and/or sagittal-plane deformities were treated in this series. Conservative measures had failed in all cases and patients had undergone a single-level PSO or extended PSO at L-2 or L-3. Fixation was accomplished using percutaneous instrumentation and interbody or facet joint fusions were used at the remaining levels. None of the procedures were aborted or converted to a traditional open procedure. Standard clinical and radiographic measures were used to assess patient outcomes. RESULTS Mean age was 68.8 years and mean follow-up duration was 17.7 months. An average of 7.6 levels were fused, and 50% of the patients had bilateral iliac screw fixation, with all constructs crossing both the thoracolumbar and lumbosacral junctions. Operative time averaged 356 ± 50 minutes and there was a mean blood loss of 843 ± 339 ml. The leg visual analog scale score improved from a mean of 5.7 ± 2.7 to one of 1.3 ± 1.6, and the back visual analog scale score improved from a mean of 8.6 ± 1.3 to one of 2.4 ± 2.1. The Oswestry Disability Index score improved from a mean of 50.1 ± 14.4 to 16.4 ± 12.7, representing a mean reduction of 36.0 ± 16.9 points. The SF-36 physical component summary score changed from a mean of 43.4 ± 2.6 to one of 47.0 ± 4.3, and the SF-36 mental component summary score changed from a mean of 46.7 ± 3.6 to 46.30 ± 3.0. Coronal alignment improved from a mean of 27.9 ± 43.6 mm to 16.0 ± 17.2 mm. The lumbar Cobb angle improved from a mean of 41.2° ± 18.4° to 15.4° ± 9.6°, and lumbar lordosis improved from 23.1° ± 15.9° to 48.6° ± 11.7°. Pelvic tilt improved from a mean of 33.7° ± 8.6° to 24.4° ± 6.5°, and the sagittal vertical axis improved from 102.4 ± 73.4 mm to 42.2 ± 39.9 mm. The final lumbar lordosis-pelvic incidence difference averaged 8.4° ± 12.1°. There were 4 patients who failed to achieve less than or equal to a 10° mismatch on this parameter. Ten of the 16 patients underwent delayed postoperative CT, and 8 of these had developed a solid arthrodesis at all levels treated. A total of 6 complications occurred in this series. There were no cases of symptomatic proximal junction kyphosis. CONCLUSIONS Advancements in minimally invasive technique have resulted in the ability to manage increasingly complex deformities with hybrid approaches. In this limited series, the authors describe the results of utilizing a tissue-sparing mini-open PSO to correct severe spinal deformities. This method was technically feasible in all cases with acceptable radiographic outcomes similar to open surgery. However, high complication rates associated with these deformity corrections remain problematic.

Pedicle-sparing transforaminal thoracic spine wedge osteotomy for kyphosis correction

Background:

Correction of a focal kyphotic deformity at times requires performing a pedicle subtraction osteotomy, which is accompanied by loss of pedicles as anchor points at the affected level in addition to significant blood loss. To help alleviate these two issues, a novel osteotomy technique for correction of kyphosis using a transforaminal approach to the thoracic vertebral body is described.

Methods:

We describe a bilateral pedicle-sparing approach and demonstrate it in a patient with proximal junctional kyphosis.

Results:

The proposed osteotomy resulted in a 28-degree Cobb angle improvement in the sagittal plane.

Conclusion:

The operation resulted in a similar degree of correction as a pedicle subtraction osteotomy, with the added benefit of maintaining the pedicles closest to the kyphotic deformity.

Osteotomies/spinal column resection in paediatric deformity

The spinal deformities in paediatric population differ from those in the adult population. Vertebral osteotomies are indicated when the deformity is too rigid to be corrected either with instrumentation alone or with the addition of soft tissue releases. When surgical intervention is to be carried out, correcting the deformity and ceasing progression should be aimed at as well as allowing further growth and improving pulmonary function. Osteotomies in the spine surgery should aim to achieve an appropriate balance in both sagittal and coronal planes. Varied clinical and radiological scenarios necessitate different osteotomy types. The purpose of this article is to introduce each osteotomy type and discuss their indications, prerequisites and complications. Osteotomy options for correcting spinal deformities are Ponte osteotomy, Smith-Petersen osteotomy, pedicle subtraction osteotomy, bone-disc-bone osteotomy and vertebral column resection. All the osteotomy types are technically demanding. Appropriate selection of the type of the osteotomy depends on the surgeons' experience, type of the deformity, magnitude of the curve, remaining growth potential and operative goals. Neuromonitoring should be an indispensible part of the procedure. Spine osteotomies are effective procedures for the treatment of paediatric spine deformities if experienced surgical team performs them.

Miniopen pedicle subtraction osteotomy: surgical technique and initial results

As minimally invasive surgery (MIS) has advanced to treat diverse diseases, there has been an increasing need for MIS surgery to be able to restore lumbar lordosis and treat sagittal balance abnormalities. In this article, the surgical technique and initial clinical and radiographic outcomes with a new miniopen pedicle subtraction osteotomy technique are outlined. Combining the MIS techniques of interbody fusion, percutaneous screw fixation, and facet fusion with a selective opening for the osteotomy site allows for safe and efficient deformity corrections. This technique resulted in an average increase of 29.2° of lumbar lordosis (range 17°-44°).

Surgical treatment of severe congenital thoracolumbar kyphosis through a single posterior approach

A combined anterior and posterior surgical approach is generally recommended in the treatment of severe congenital kyphosis, despite the fact that the anterior vascular supply of the spine and viscera are at risk during exposure. The aim of this study was to determine whether the surgical treatment of severe congenital thoracolumbar kyphosis through a single posterior approach is feasible, safe and effective.

We reviewed the records of ten patients with a mean age of 11.1 years (5.4 to 14.1) who underwent surgery either by pedicle subtraction osteotomy or by vertebral column resection with instrumented fusion through a single posterior approach.

The mean kyphotic deformity improved from 59.9° (45° to 110°) pre-operatively to 17.5° (3° to 40°) at a mean follow-up of 47.0 months (29 to 85). Spinal cord monitoring was used in all patients and there were no complications during surgery. These promising results indicate the possible advantages of the described technique over the established procedures. We believe that surgery should be performed in case of documented progression and before structural secondary curves develop. Our current strategy after documented progression is to recommend surgery at the age of five years and when 90% of the diameter of the spinal canal has already developed.

Cite this article: Bone Joint J 2013;95-B:1527–32.

Perioperative Outcomes and Complications of Pedicle Subtraction Osteotomy in Cases With Single Versus Two Attending Surgeons

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To assess the perioperative morbidity of pedicle subtraction osteotomy (PSO) based on the presence of 1 versus 2 attending surgeons.

BACKGROUND SUMMARY

Pedicle subtraction osteotomies are challenging cases with high complication rates and substantial physiological burden on patients. The literature supports the benefits of 2-surgeon strategies in complex cases in other specialties.

METHODS

We reviewed a single institution database of all pedicle subtraction osteotomies (78 cases) from 2005-2010 and divided the cohort into single versus 2-surgeon groups (42 vs. 36 cases, respectively). We performed subset analysis after excluding cases before 2007 and excluding patients with staged anterior and posterior procedures. We analyzed cases for estimated blood loss, length of surgery, length of stay, radiographic analysis, rate of return to the operating room within 30 days, and medical and neurological complications.

RESULTS

The groups were similar when comparing mean number of posterior levels fused, levels decompressed and revision rates, however, the average age of the single surgeon and 2 surgeon groups was 57.6 and 64.3 years, respectively (p = .02). The 2 groups had comparable correction of radiographic parameters. Mean percent estimated blood loss for single versus 2 surgeons was 109% versus 35% (p < .001) and estimated blood loss was 5,278 versus 2,003 mL (p < .001). Average surgical time for single versus 2 surgeons was 7.6 versus 5.0 hours (p < .001). A total of 45% of single-surgeon patients compared with 25% of 2-surgeon patients experienced at least 1 major complication within 30 days. In the single-surgeon group, 19% had unplanned surgery within 30 days, versus 8% in the 2-surgeon group.

CONCLUSIONS

The use of 2 surgeons at an experienced spine deformity center decreases the operative time and estimated blood loss, and may be a key factor in witnessed decreased major complication prevalence. This approach also may decrease the rate of premature case termination and return to operating room in 30 days.

Changes in thoracic kyphosis negatively impact sagittal alignment after lumbar pedicle subtraction osteotomy: a comprehensive radiographic analysis

STUDY DESIGN

Consecutive, multicenter retrospective review.

OBJECTIVE

To evaluate if change in thoracic kyphosis (TK) has a positive or negative impact on spinopelvic alignment after lumbar pedicle subtraction osteotomy (PSO) with short fusions.

SUMMARY OF BACKGROUND DATA

In the setting of sagittal malalignment, the effect of large vertebral resections can now be anticipated in long fusions, but their impact on unfused segments (reciprocal changes [RC]) remains poorly understood.

METHODS

A total of 34 adult patients (mean age = 54 years; SD = 12) who underwent lumbar PSO with upper instrumented vertebra below T10 were included. Radiographic analysis included pre- and postassessment of TK, lumbar lordosis (LL), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were analyzed to determine successful realignment. RC in the thoracic spine was designated favorable or unfavorable on the basis of impact on final SVA and PT.

RESULTS

Mean PSO resection was 26°. LL increased from 20° to 49° (P < 0.001). SVA improved from 14 to 4 cm (P < 0.001), and PT improved from 33° to 25° (P < 0.001). Mean increase in TK was 13° (P = 0.002) but was unchanged in 11 patients. Five patients had a favorable RC, and 18 patients had an unfavorable RC. Unfavorable RC was attributed to junctional failure in 6 of 18 patients. Significant differences in the unfavorable RC group included age and greater preoperative PT, PI, SVA, and T1SPI.

CONCLUSION

Significant postoperative alignment changes can occur through unfused thoracic spinal segments after lumbar PSO. Unfavorable RC may limit optimal correction and lead to clinical failures. Risk factors for unfavorable thoracic RC include older patients, larger preoperative PI and PT, and worse preoperative T1SPI and are not simply due to junctional failure. Care should be taken with selective lumbar fusion and PSO in older patients and in those with severe preoperative spinopelvic parameters.

Sagittal spino-pelvic alignment failures following three column thoracic osteotomy for adult spinal deformity

PURPOSE

Three column thoracic osteotomy (TCTO) is effective to correct rigid thoracic deformities, however, reasons for residual postoperative spinal deformity are poorly defined. Our objective was to evaluate risk factors for poor spino-pelvic alignment (SPA) following TCTO for adult spinal deformity (ASD).

METHODS

Multicenter, retrospective radiographic analysis of ASD patients treated with TCTO. Radiographic measures included: correction at the osteotomy site, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were assessed to determine if ideal SPA (SVA < 4 cm, PT < 25°) was achieved. Differences between the ideal (IDEAL) and failed (FAIL) SPA groups were evaluated.

RESULTS

A total of 41 consecutive ASD patients treated with TCTO were evaluated. TCTO significantly decreased TK, maximum coronal Cobb angle, SVA and PT (P < 0.05). Ideal SPA was achieved in 32 (78%) and failed in 9 (22%) patients. The IDEAL and FAIL groups had similar total fusion levels and similar focal, SVA and PT correction (P > 0.05). FAIL group had larger pre- and post-operative SVA, PT and PI and a smaller LL than IDEAL (P < 0.05).

CONCLUSIONS

Poor SPA occurred in 22% of TCTO patients despite similar operative procedures and deformity correction as patients in the IDEAL group. Greater pre-operative PT and SVA predicted failed post-operative SPA. Alternative or additional correction procedures should be considered when planning TCTO for patients with large sagittal global malalignment, otherwise patients are at risk for suboptimal correction and poor outcomes.

Sagittal balance analysis after pedicle subtraction osteotomy in ankylosing spondylitis

INTRODUCTION

This is a radiographic study of ankylosing spondylitis patients with severe fixed kyphotic deformity who underwent pedicle subtraction osteotomy. Our goal was to measure and validate new angle to assess global kyphosis and to evaluate the sagittal balance after surgery. This is the first report which describes new angle to assess global kyphosis (T1-S1).

MATERIALS AND METHODS

Pre and postoperative controls were compared according to the Pelvic Incidence. The sagittal parameters ankylosing spondylitis patients were compared with 154 asymptomatic patients. In addition to the pelvic parameters and the C7 tilt, we used the spino-sacral angle.

RESULTS

Pelvic incidence in ankylosing spondylitis patients was higher than asymptomatic population (61° vs. 51°). For a same tilt of C7 for both groups, the low pelvic incidence group had a lower sacral slope and pelvic tilt and a higher global kyphosis (spino-sacral angle = 90°) than the high pelvic incidence group (spino-sacral angle = 98°). In the adult volunteers, the C7 tilt and spino-sacral angle measured, respectively, 95° and 135°. The preoperative C7 tilt measured 73° and increased to 83° (p = 0.0025). The preoperative spino-sacral angle measured 96° and increased to 113.3° (p = 0.003).

CONCLUSION

A low pelvic incidence pelvis has a lower sacral slope than in high pelvic incidence and can support a bigger kyphosis. All the parameters were improved by the pedicle subtraction osteotomy, but the average spinosacral angle remained lower than the control group. When C7 tilt was useful to assess the improvement of the sagittal balance, SSA allowed a better evaluation of the correction of kyphosis itself.

An increased kyphosis of the thoracolumbar junction is correlated to more axial vertebral rotation in thoracolumbar/lumbar adolescent idiopathic scoliosis

STUDY DESIGN

A retrospective correlation study.

OBJECTIVE

To identify radiographically if there is a correlation of the sagittal thoracolumbar alignment to the axial vertebral rotation and coronal scoliotic curvature in thoracolumbar/lumbar (TL/L) adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

The consistent positive correlation between coronal angulations and axial rotation has been defined as a typical feature of AIS. However, the correlation of sagittal alignment transformation to axial and/or coronal deformity has not been definitely described, especially for primary TL/L AIS.

METHODS

On standard anteroposterior and lateral radiographs of 43 patients with TL/L AIS, coronal and sagittal parameters including primary TL/L and compensatory thoracic curve, thoracic kyphosis, thoracolumbar junctional sagittal curve (TLJS), and lumbar lordosis, were evaluated using the Cobb method. Apical vertebral rotation (AVR) was evaluated using the Perdriolle torsionmeter. The correlation was investigated between all parameters. After the patients were divided into 2 subgroups according to the TLJS curvature, the average AVR and coronal TL/L Cobb were compared between the 2 groups.

RESULTS

The average TLJS Cobb was 4.5° ± 8.8° (range, -12.5°-24.3°) with 28 cases (65.1% of all cases) in TLJS+ (kyphosis) group and 15 cases in TLJS- (lordosis) group. Significant correlations were observed between AVR and coronal TL/L curvature (P < 0.001), and between AVR and sagittal TLJS Cobb angle (P < 0.001). These correlations still existed when the partial correlation analysis was conducted. The correlation between sagittal TLJS and coronal TL/L curvature became nonsignificant (P = 0.405) when the partial correlation analysis was conducted with AVR as control variable. Besides, a significant difference of 7.0° was observed in average AVR between TLJS+ and TLJS- subgroups (P < 0.001).

CONCLUSION

From the standard anteroposterior and lateral radiographs, an increased kyphosis of the thoracolumbar junction was observed in TL/L AIS, and it was demonstrated to be positively correlated to more axial vertebral rotation of the scoliotic spine.

Osteotomies in the posterior-only treatment of complex adult spinal deformity: a comparative review

In addressing adult spinal deformities through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. The Ponte or Smith-Petersen osteotomy provides the least correction, but it can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies but carry increased technical demands, longer operative time, and greater blood loss and associated morbidity. Vertebral column resections serve as the most powerful method, providing the most correction in the coronal and sagittal planes, but posing both the greatest technical challenge and the greatest risk to the patient in terms of possible neurological injury, operative time, and potential morbidity. The authors reviewed the literature relating to these osteotomy methods. They also provided case illustrations and suggestions for their proper application.

Radiological analysis of ankylosing spondylitis patients with severe kyphosis before and after pedicle subtraction osteotomy

This is a radiographic study of ankylosing spondylitis patients with severe fixed kyphotic deformity who underwent pedicle subtraction osteotomy. Our goal was to measure and validate new angle to assess global kyphosis and to evaluate the radiological outcomes after surgery. This is the first report which describes new angle to assess global kyphosis (T1-S1). Pre and postoperative controls were compared according to the Pelvic Incidence. The sagittal parameters ankylosing spondylitis patients were compared with 154 asymptomatic patients. In addition to the pelvic parameters and the C7 tilt, we used the spino-sacral angle. Pelvic incidence in ankylosing spondylitis patients was higher than asymptomatic population (61 vs. 51 degrees). For a same tilt of C7 for both groups, the low pelvic incidence group had a lower sacral slope and pelvic tilt and a higher global kyphosis (spino-sacral angle = 90 degrees) than the high pelvic incidence group (spino-sacral angle = 98 degrees ). In the adult volunteers, the C7 tilt and spino-sacral angle measured, respectively, 95 and 135 degrees. The preoperative C7 tilt measured 73 degrees and increased to 83 degrees (p = 0.0025). The preoperative spino-sacral angle measured 96 degrees and increased to 113.3 degrees (p = 0.003). A low pelvic incidence pelvis has a lower sacral slope than in high pelvic incidence and can support a bigger kyphosis. All the parameters were improved by the pedicle subtraction osteotomy, but the average spino-sacral angle remained lower than the control group. When C7 tilt was useful to assess the improvement of the balance, SSA allowed a better evaluation of the correction of kyphosis itself.

PEDICLE SUBTRACTION OSTEOTOMY

OBJECTIVE

Pedicle subtraction osteotomy (PSO) is an effective tool for the correction of fixed sagittal plane deformity. However, there is potentially significant perioperative morbidity associated with this technique. We report our perioperative morbidity rate in recently performed PSO cases treated with our present surgical, anesthetic, and monitoring techniques and discuss complication-avoidance strategies.

METHODS

We conducted a retrospective study of 10 patients (mean age, 56 yr; range, 7–77 yr) undergoing thoracolumbar PSO at a single institution in the past 3 years. Two patients underwent PSO at T12, seven patients underwent PSO at L3, and one patient underwent PSO at L2. Eight of the patients had undergone at least one previous spine surgery in the region of the PSO, and nine of the patients had comorbidities that increased their surgical risk stratification. We identified all causes of perioperative morbidity.

RESULTS

We classified perioperative complications into two categories: intraoperative and early postoperative. Intraoperative complications included dural tears in two patients, cardiovascular instability in one patient, and coagulopathy in two patients. Early postoperative complications included neurological deficit (one patient), wound infection (two patients), urinary tract infection (one patient), and delirium (two patients). All patients recovered fully from these complications. There was no mortality in this series.

CONCLUSION

In this series, most patients undergoing PSO had multiple previous spine surgeries and comorbidities. The risk of perioperative morbidity for revision cases undergoing PSO was in excess of 50%. We discuss complication-avoidance strategies.

Forced lordosis on the thoracolumbar junction can correct coronal plane deformity in adolescents with double major curve pattern idiopathic scoliosis

STUDY DESIGN

A prospective radiographic study was conducted.

OBJECTIVE

To support our hypothesis that correction of the scoliosis may benefit from a lordotic fulcrum force in the sagittal plane on the thoracolumbar spine.

SUMMARY OF BACKGROUND DATA

Adolescent idiopathic scoliosis is an important spinal deformity. Correction can be achieved with limited options by current bracing techniques. Lateral bending radiographs are used to assess flexibility and predict treatment outcome. The corrective potential of a lordotic fulcrum force in the sagittal plane has not been addressed.

METHODS

Anterioposterior spine radiographs of patients with a double major curve pattern scoliosis were obtained in 2 groups of patients. In group A radiographs in 3 positions: standing, and supine with and without fulcrum (n = 12), and group B radiographs in 2 positions (n = 28): standing, and supine with lordotic fulcrum. Cobb angles were determined and evaluated statistically. The sagittal contour of the thoracolumbar junction in standing position was measured.

RESULTS

In group A with the patients lying supine a correction of the Cobb angle was obtained at the thoracic level of 15.4% and the lumbar level of 27.5% (P < 0.001). Adding in supine position a lordotic fulcrum on the thoracolumbar junction resulted in a coupled further correction at the thoracic level of 15.7% and lumbar 18.1% (P < 0.001). Comparing in group A the thoracic and lumbar curvatures in standing position with that on a lordotic fulcrum in supine position revealed a total reduction of 31% and 45.6%, respectively. For the independent group B this reduction in 1 step is 38% and 44.4%, respectively.

CONCLUSION

Scoliotic deformities are significantly reduced in supine position by a lordotic fulcrum force on the thoracolumbar junction. These findings may have consequences on bracing techniques.

A single posterior approach for multilevel modified vertebral column resection in adults with severe rigid congenital kyphoscoliosis: a retrospective study of 13 cases

We report a multilevel modified vertebral column resection (MVCR) through a single posterior approach and clinical outcomes for treatment of severe congenital rigid kyphoscoliosis in adults. Transpedicular eggshell osteotomies and vertebral column resection are two techniques for the surgical treatment of rigid severe spine deformities. The authors developed a new technique combining the two surgical methods as a MVCR, through a single posterior approach, for surgical treatment of severe congenital rigid kyphoscoliosis in adults. Thirteen adult patients with severe rigid congenital kyphoscoliosis deformity were treated by a single posterior approach using a MVCR technique. The surgery processes included a one-stage posterior transpedicular eggshell technique first, and then expanded the eggshell technique to adjacent intervertebra space through abrasive reduction of the vertebral cortices from inside out. All posterior vertebral elements were removed including the cortical vertebral bone around the neural canal. Range of resection of the vertebral column at the apex of the deformity included apical vertebra and both cephalic and/or caudal adjacent wedged vertebrae. Totally, 32 vertebrae had been removed in 13 patients, with 2.42 vertebrae being removed on average in each case. The average fusion extent was 7.69 vertebrae. Mean operation time was 266 min with average blood loss of 2,411.54 ml during operation. Patients were followed up for an average duration of 2.54 years. Deformity correction was 59% in the coronal plane (from 79.7 degrees to 32.4 degrees ) postoperatively and 33.7 degrees (57% correction) at 2 years follow-up. In the sagittal plane, correction was from preoperative 85.9 degrees to 27.5 degrees immediately after operation, and 32.0 degrees at 2 years follow-up. Postoperative pain was reduced from preoperative 1.77 to 0.54 at 2 years follow-up in visual analog scale. SRS-24 scale was from 38.2 preoperatively to 76.9 at 2 years follow-up postoperative. Complications were encountered in four patients (30.7%) with transient neurology that spontaneously improved without further treatment within 3 months. MVCR technique through a single posterior approach is an effective procedure for the surgical treatment of severe congenital rigid kyphoscoliosis in adults.