Uninstrumented in situ fusion for high-grade childhood and adolescent isthmic spondylolisthesis: long-term outcome

Clinical and radiological outcomes of gradual reduction and circumferential fusion of high-grade spondylolisthesis in adolescents: a prospective cohort study of 29 young patients

AIM

The objective of this study was to evaluate the safety and efficacy of a novel technique of formal reduction and circumferential fusion for pediatric high-grade spondylolisthesis (HGS).

PURPOSE

The safety and efficacy of formal reduction for high-grade spondylolisthesis (HGS) has never been thoroughly examined. This study reports the outcomes of 29 children with HGS who underwent a procedure of gradual reduction and circumferential fusion.

METHODS

29 children (13 males, 16 females) were recruited between 2006 and 2010. Radiographic measurements (including % of slip, lumbosacral angle-LSA, pelvic incidence-PI, pelvic tilt-PT, sacral slope-SS, and proximal femoral angle-PFA) and quality of life assessment (SRS-22 questionnaire) were prospectively obtained at baseline and at the last post-operative follow-up (> 2 years post-op). Radiological measurements were used to classify patients according to the Spine Deformity Study Group (SDSG) classification.

RESULTS

Mean baseline slip % was 69.9 ± 16.5%. There were 13 patients with a balanced pelvic (SDSG Type 4) and 16 with an unbalanced pelvis (SDSG Type 5 and 6). On average, a reduction of 45.5 ± 15.3% (range 20-86%) was achieved safely with no major complication. In particular, of the 29 patients, only 3 had a L5 radiculopathy postoperatively that was self-resolved at follow-up. From a radiological standpoint, we observed a mean improvement of LSA from 80.3 ± 17.9° to 91.7 ± 13.6°. We also observed a statistically significant improvement in global HRQOL, and in the function and body image domains.

CONCLUSION

This prospective study suggests that formal reduction of HGS followed by circumferential fusion is safe when using a standardized surgical technique based on gradual reduction. Performing this intervention could also help improve QOL in some patients.

An Alternative Operative Approach to Lumbar Spondylolisthesis

Lumbosacral spondylolisthesis is a frequently encountered pathology with high-grade spondylolisthesis being the least common. A circumferential construct is usually the preferred treatment as these can resist the shearing forces present at L5-S1. However, the severity of the slip, sacral inclination, and the slip angle may make a traditional anterior approach difficult to achieve. In this case series, we present three patients with axial back pain that were treated with an anterior L5-S1 transvertebral cage. This technique is intended for both grade II spondylolisthesis and high sacral slope. The L5-S1 transvertebral cage may be sufficient to prevent further listhesis, fuse the patient, and alleviate axial back pain.

Health-related quality of life and sagittal balance at two to 25 years after posterior transfixation for high-grade dysplastic spondylolisthesis

Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.

Methods

SRS-22r and full-spine lateral radiographs were collected for the 28 young patients (age 13.4 years (SD 2.6) who underwent surgery for high-grade dysplastic spondylolisthesis in our centre (Scottish National Spinal Deformity Service) between 1995 and 2018. The mean follow-up was nine years (2 to 25), and one patient was lost to follow-up. The standard surgical technique was an all-posterior, partial reduction, and S1 to L5 transfixation screw technique without direct decompression. Parameters for segmental (slip percentage, Dubousset’s lumbosacral angle) and regional alignment (pelvic tilt, sacral slope, L5 incidence, lumbar lordosis, and thoracic kyphosis) and global balance (T1 spino-pelvic inclination) were measured. SRS-22r scores were compared between patients with a balanced and unbalanced pelvis at final follow-up.

Results

SRS-22r domain and total scores improved significantly from preoperative to final follow-up, except for the mental health domain that remained the same. Slip percentage improved from 75% (SD 15) to 48% (SD 19) and lumbosacral angle from 70° (SD 11) to 101° (SD 11). Preoperatively, 35% had global imbalance, and at follow-up all were balanced. Preoperatively, 63% had an unbalanced pelvis, and at final follow-up this was 32%. SRS-22r scores were not different in patients with a balanced or unbalanced pelvis. However, postoperative pelvic imbalance as measured by L5 incidence was associated with lower SRS-22r self-image and total scores (p = 0.029).

Conclusion

In young patients with HGDS, partial reduction and transfixation improves local lumbosacral alignment, restores pelvic, and global balance and provides satisfactory long-term clinical outcomes. Higher SRS-22r self-image and total scores were observed in the patients that had a balanced pelvis (L5I < 60°) at two to 25 years follow-up.

Cite this article: Bone Jt Open 2021;2(3):163–173.

Does the Surgical Reduction of High Grade Spondylolisthesis Restore Spino-Pelvic Alignment? An Analysis of 35 Patients

STUDY DESIGN

Retrospective case series.

PURPOSE

This study aimed to analyze how the sagittal spinopelvic alignment is influenced by an attempted surgical reduction of the L5-S1 segment in patients with high-grade spondylolisthesis (HGS).

OVERVIEW OF LITERATURE

Conventional treatment strategies stress the importance of achieving fusion across the lumbosacral junction in patients with HGS. The role of reduction in this subset of patients is controversial.

METHODS

This is a retrospective case series of 35 patients with Meyerding grades III, IV, or V spondylolisthesis who underwent surgical treatment in our institution. Before and after surgery, we took standing lateral radiographs from L1 vertebra to pelvis, including the femoral heads, and measured the slip grade, pelvic incidence, sacral slope, pelvic tilt, lumbosacral angle, and lumbar lordosis. Patients were subdivided into "balanced" and "unbalanced" pelvis groups. To determine the effect and correlation of reduction on these spinopelvic parameters, we statistically compared the pre- and postoperative measurements.

RESULTS

The average follow-up was 9 months (range, 3-169 months). Slip grade improved from an average 74.0%±13.2% to 30.0%±14.0% (p<0.001), and lumbosacral angle reduced from an average 32.0°±11.6° to 6.0°±0.6° (p<0.001). Although the pelvic tilt was reduced, this was not significant. There was a modest negative correlation between the reduction in slip grade and the increase in sacral slope (r=-0.3, p=0.06). At follow-up, five patients improved, from an unbalanced pelvis to a balanced pelvis. Fusion occurred in 33 patients (95%).

CONCLUSIONS

Surgical reduction of HGS restores the lumbosacral alignment. However, a similar trend is not noted with the pelvic parameters.

Outcomes of Various Treatment Modalities for Lumbar Spinal Ailments in Elite Athletes: A Literature Review

Lumbar spinal injuries are common in elite athletes, who can present with a spectrum of ailments ranging from lumbar strain to prolapsed intervertebral discs. Sequelae can include neurological impairment and lumbar instability among other possible outcomes. This group of patients is unique in terms of their clinicoradiological presentation and treatment modalities. The primary goals of treatment are a rapid return to play and prevention of recurrence, thus prolonging the athlete’s professional career. Treatment modalities can range from activity restriction to nerve root blocks and surgery. A successful treatment outcome is based on timely diagnosis, treatment suiting the demands of the particular sport, and early rehabilitation. A multidisciplinary team approach involving the coach, rehabilitation specialist, pain management specialist, and spine surgeon helps in planning appropriate treatment. In this article, we review special considerations in the elite athletic population with lumbar spinal ailments as well as the outcomes of various treatment modalities.

Is Stand-Alone Anterior Lumbar Interbody Fusion a Safe and Efficacious Treatment for Isthmic Spondylolisthesis of L5-S1?

STUDY DESIGN

A systematic review.

OBJECTIVE

The objective of this study was to determine the safety and efficacy of stand-alone anterior lumbar interbody fusion (sa-ALIF) for the treatment of symptomatic isthmic spondylolisthesis of L5-S1 by assessing the level of available clinical and radiographic evidence.

METHODS

A systematic review utilizing Medline, Embase, and Scopus online databases was undertaken. Clinical, radiographic, and adverse outcome data were extracted for the relevant isthmic spondylolisthesis cases with the intention of undertaking a meta-analysis.

RESULTS

The database search between January 1980 and December 2015 yielded 23 articles that concerned sa-ALIF for isthmic spondylolisthesis of L5-S1. Only in 9 of the 23 articles data could be extracted specific to sa-ALIF for isthmic spondylolisthesis of L5-S1. There was considerable inconsistency in the standards for reporting outcomes of the surgery due to which meta-analysis could not be undertaken, and hence each article was reviewed.

CONCLUSIONS

There was insufficient evidence to support the safety and efficacy of sa-ALIF for the treatment of isthmic spondylolisthesis of L5-S1. Although sa-ALIF is widely documented in the literature, there was insufficient evidence to support its use in treating this specific pathology. The unique pathological and anatomical situation that isthmic spondylolisthesis of L5-S1 presents must be recognized and its treatment with sa-ALIF should be well thought out.

Outcome of L5 radiculopathy after reduction and instrumented transforaminal lumbar interbody fusion of high-grade L5-S1 isthmic spondylolisthesis and the role of intraoperative neurophysiological monitoring

PURPOSE

To evaluate the incidence and course of iatrogenic L5 radiculopathy after reduction and instrumented fusion of high-grade L5-S1 isthmic spondylolisthesis and the role of intraoperative neurophysiological monitoring (IONM).

METHODS

Consecutive patients treated for high-grade spondylolisthesis with IONM from 2005 to 2013 were screened for eligibility. Prospectively collected clinical and surgical data as well as radiographic outcomes were analyzed retrospectively. Patients completed the multidimensional Core Outcome Measures Index (COMI) before and at 3, 12, and 24 months after surgery.

RESULTS

Seventeen patients were included, with a mean age of 26.3 (±9.5) years. Mean preoperative L5-S1 slip was 72% (±21%) and was reduced to 19% (±13%) postoperatively. Mean loss of reduction at last follow-up [mean 19 months (±14, range 3-48 months)] was 3% (±4.3%). Rate of new L5 radiculopathy with motor deficit (L5MD) after surgery was 29% (five patients). Four patients fully recovered after 3 months, one patient was lost to neurologic follow-up. IONM sensitivity and specificity for postoperative L5MD was 20 and 100%, respectively. COMI, back pain and leg pain scores showed significant (p < 0.001) improvements at 3 months postoperatively, which were retained up to 24 months postoperatively.

CONCLUSIONS

Transient L5 radiculopathy after reduction and instrumented fusion of high-grade spondylolisthesis is frequent. With IONM the risk of irreversible L5 radiculopathy is minimal. If IONM signal changes recover, full clinical recovery is expected within 3 months. Overall, patient-reported outcome of reduction and instrumented fusion of high-grade spondylolisthesis showed clinically important improvement.

Operative management of high-grade dysplastic L5 spondylolisthesis with the use of external transpedicular fixation: advantages and drawbacks

PURPOSE

The aim of our study was to analyze clinical and radiographic outcomes of operative management of L5 high-grade dysplastic spondylolisthesis with the apparatus for external transpedicular fixation (AETF), and to compare the results of its use for reduction and spondylodesis.

METHODS

There were 13 patients with L5 dysplastic spondylolisthesis of grade 4 (Meyerding grading) and having a mean age of 25.0 ± 3.6 years. The management included two stages: gradual reduction with the AETF, followed by either isolated anterior spondylodesis with the same AETF (group 1, n = 8), or by spondylodesis using a combined method (internal transpedicular instrumentation and posterior lumbar interbody fusion [PLIF]) (group 2, n = 5). Clinical evaluation included pain (VAS scale) and functional status (Oswestry questionnaire [ODI]). Reduction and fusion completeness were assessed radiographically after treatment and at a mean follow-up of 2.1 ± 0.4 years.

RESULTS

Initial slippage was reduced by 51.6 % with AETF and was of grade 1 or 2. Reduction made up 31.1 % at follow-ups (grade 2 or 3). Pain decreased by 57.6 % (p < 0.01). The functional status improved. ODI decreased by 37.7 % (p < 0.01) after treatment and by 41.7 % (p < 0.01) at follow-ups. Fusion at the level of the involved segment was poor in group 1. All the cases fused in group 2.

CONCLUSIONS

The use of AETF for L5 high-grade dysplastic spondylolisthesis provides gradual controlled reduction of the slipped vertebra, decompression of cauda equine roots, and recovery of the local sagittal spinal column balance. It creates conditions for achieving stability of lumbosacral segments with combined spondylodesis (internal transpedicular instrumentation and PLIF). AETF is not suitable for spondylodesis due to a high rate of pseudarthrosis.

Transsacral transdiscal L5-S1 screws for the management of high-grade spondylolisthesis in an adolescent

The surgical management of high-grade spondylolisthesis in adolescents remains a controversial issue. Because the basic procedure, posterolateral fusion, is associated with a significant rate of pseudarthrosis and listhesis progression, there is a pressing need for alternative surgical techniques. In the present report, the authors describe the case of an adolescent patient with significant low-back pain who was found to have Grade IV spondylolisthesis at L5-S1 that was treated with transsacral transdiscal screw fixation. Bilateral pedicle screws were placed starting from the top of the S-1 pedicle, across the L5-S1 intervertebral disc space, and into the L-5 body. At 14 months after surgery, the patient had considerable improvement in his pain and radiographic fusion across L5-S1. The authors conclude that transsacral transdiscal pedicle screws may serve as an efficacious and safe option for the correction of high-grade spondylolisthesis in adolescent patients.

Pediatric Return to Sports After Spinal Surgery

CONTEXT

Pediatric patients who undergo spinal surgery are frequently involved in sporting activities. Return to play is often an important postoperative concern for the patient and family.

EVIDENCE ACQUISITION

A PubMed search was conducted for articles in the English language on return to play after treatment of pediatric acute disc herniation, degenerative disc disease, spondylolysis, spondylolisthesis, and scoliosis from 1980 to 2015. Reference lists were reviewed for additional pertinent articles. We included articles that focused on return to sports after surgical treatment of these conditions in this review.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

There are no published guidelines, and most of the literature in this area has focused on return to play after spinal injury rather than after spinal surgery. Most children and adolescents have excellent outcomes with minimal pain at 1 year after lumbar discectomy. The majority of surgeons allow return to full activity once pain-free range of motion and strength are regained, typically at 8 to 12 weeks postoperatively. Pediatric patients with spondylolysis have good outcomes after direct pars repair. Satisfactory outcomes have been demonstrated after fusion for low- and high-grade spondylolisthesis. Most surgeons allow return to noncontact sports by 6 months after surgical treatment of spondylolysis and spondylolisthesis. Return to contact and collision sports is controversial. After posterior spinal fusion for scoliosis, most surgeons allow return to noncontact sports by 3 months and return to contact sports between 6 months and 1 year. Return to collision sports is controversial.

CONCLUSION

There is little evidence to guide practitioners on return to sports after pediatric spinal surgery. Ultimately, the decision to allow any young athlete to resume sports participation after spinal injury or surgery must be individualized.

What is the optimum fusion technique for adult spondylolisthesis-PLIF or PLF or PLIF plus PLF? A meta-analysis from 17 comparative studies

STUDY DESIGN

A meta-analysis and systemic review.

OBJECTIVE

To pool scientific evidence for the optimum selection in the treatment of lumbar spondylolisthesis by comparing the clinical effect of posterolateral fusion (PLF), posterior lumbar interbody fusion (PLIF), and PLIF plus PLF.

SUMMARY OF BACKGROUND DATA

Clinical effect of the 3 fusion techniques has been reported in many studies. However, which is the best method is in dispute.

METHODS

A systematic search was conducted in MEDLINE, EMBASE, and the Cochrane Collaboration Library from January 1950 through May 2013. Comparative studies were performed according to eligibility criteria. Weighted mean differences and risk differences were calculated for common outcomes. The final strength of evidence was expressed as different level recommended by the Grading of Recommendations Assessment, Development, and Evaluation Working Group.

RESULTS

Four randomized controlled trials and 13 observational studies were eligible. PLIF was more effective than PLF in the improvement of clinical satisfaction (odds ratio [OR], 0.52; 95% confidence interval (CI), 0.31-0.89; P=0.02). No significant differences in the primary outcomes were seen between PLIF plus PLF and PLF (OR, 0.88; 95% CI, 0.47-1.64; P=0.69). For the complication rate, the differences were not significant between PLIF and PLF, and between PLIF plus PLF and PLF (OR, 2.27; 95% CI, 0.95-5.42; P=0.07; OR, 0.74; 95% CI, 0.22-2.44; P=0.62, respectively). In the secondary outcomes, PLIF was more effective than PLF in the improvement of fusion rate (P=0.0007) and reoperation rate (P=0.004). However, PLIF plus PLF failed to reveal more superiority than PLF (P>0.05).

CONCLUSION

PLIF plus PLF did not show more superiority than PLF alone. PLIF alone improved clinical satisfaction and decreased complication rate compared with PLF. PLIF maybe be better than the other 2 fusion methods in the treatment of lumbar spondylolisthesis. However, conclusions need to be treated with caution because of lack of high quality of evidence.

LEVEL OF EVIDENCE

1.

Minimal access bilateral transforaminal lumbar interbody fusion for high-grade isthmic spondylolisthesis

PURPOSE

Minimally invasive or "minimal access surgery" (MAS) is being utilized with increasing frequency to reduce approach-related morbidity in the lumbar spine. This paper describes our minimal access technique for posterior bilateral transforaminal lumbar interbody fusion (TLIF) and spinal instrumentation in a patient with high-grade spondylolisthesis grade (Myerding Grade III) with 5-year follow-up.

METHODS

A 24-year-old lady presented with mechanical back pain and left leg L5 radiculopathy. On examination, she was a thin lady with an obvious step deformity in the lower lumbar spine and otherwise, a normal neurological examination. Imaging showed a grade III isthmic L5-S1 spondylolisthesis with foraminal stenosis and focal kyphotic alignment of 20° [slip angle (SA) = 70°]. Conservative measures had failed, and a decision was made to proceed with a MAS-TLIF approach.

RESULTS

The estimated blood loss was less than 100 ml, operating time 150 min, and post-operative hospital stay was 4 days. Post-operatively the patient had significant improvement of back and radicular pain. Improvement in ODI was substantial and sustained at 5 years. A solid fusion was achieved at 8 months. The slip percentage improved from 68 % (pre-op) to 28 % (post-op) and the focal alignment to 20° lordosis (SA = 110°).

CONCLUSIONS

A MAS approach for selected patients with a mobile high-grade spondylolisthesis is feasible, safe and clinically effective, with the added benefit of reduced soft-tissue disruption. Our result of this technique suggests that the ability to correct focal deformity, and achieve excellent radiographic and clinical outcome is similar to the open procedure.

Transdiscal L5-S1 screws for the treatment of adult spondylolisthesis

PURPOSE

The aim of the study was to evaluate clinical and radiographic outcome of patients treated with a modified Grob technique analysing the advantages related to increased mechanical stability.

METHODS

30 patients that underwent "in situ" fusion for L5-S1 spondylolisthesis were evaluated. All patients presented a low-dysplastic developmental L5-S1 spondylolisthesis. Patients were divided into two groups: A, in which L5-S1 pedicle instrumentation associated with transsacral screw fixation was performed, and B, in which L5-S1 pedicle instrumentation associated with a posterolateral interbody fusion (PLIF) was performed.

RESULTS

Patients treated with transdiscal L5-S1 fixation observed a faster resolution of the symptoms and a more rapid return to daily activities, especially at 3-6 months' follow-up. The technique is reliable in giving an optimal mechanical stability to obtain a solid fusion.

CONCLUSIONS

The advantages of this technique are lower incidence of neurologic complications, speed of execution and faster return to normal life.

Sacral dome resection and single-stage posterior reduction in the treatment of high-grade high dysplastic spondylolisthesis in adolescents and young adults

OBJECTIVE

The description of the operation technique and retrospective review of 15 consecutive patients who were treated by posterior sacral dome resection and single-stage reduction with pedicle screw fixation for high-grade, high-dysplastic spondylolisthesis.

MATERIALS AND METHODS

All the patients had high-grade, high-dysplastic spondylolisthesis L5 and were treated by posterior sacral dome resection and posterior single-stage reduction from L4-S1. The average age at the time of surgery was 17.3 (11-28) years. The average follow-up time is 5.5 (2-11.6) years. Clinical and radiological data were retrospectively reviewed.

RESULTS

Spondylolisthesis was reduced from average 99% preoperative to 29% at the last follow-up. L5 incidence improved from 74° to 56°, the lumbosacral angle improved from 15° kyphosis to 6° lordosis, lumbar lordosis decreased from 69° to 53° from preoperative to the last follow-up. While pelvic incidence of 77° remained unchanged, sacral slope decreased from 51° to 46° and pelvic tilt increased from 25° to 30°. Clinical outcome was subjectively rated to be much better than before surgery by 14 out of 15 patients. Four out of 15 patients had temporary sensory impairment of the L5 nerve root which resolved completely within 12 weeks. There were no permanent neurological complications or no pseudarthrosis.

CONCLUSION

The sacral dome resection is a shortening osteotomy of the lumbosacral spine which allows a single-stage reduction of L5 without lengthening of lumbosacral region in high-grade spondylolisthesis, which helps to avoid neurological complications. This is a safe surgical technique resulting in a good multidimensional deformity correction and restoration of spino-pelvic alignment towards normal values with a satisfactory clinical outcome.

A new three-stage spinal shortening procedure for reduction of severe adolescent isthmic spondylolisthesis: a case series with medium- to long-term follow-up

STUDY DESIGN

A case series of eight consecutive patients with severe (Meyerding Grade ≥ 3) adolescent isthmic spondylolisthesis (SAIS) who underwent reduction and stabilization by using a new surgical technique.

OBJECTIVE

To report the results of a safe three-stage spinal shortening procedure in a single operative session in eight patients with SAIS.

SUMMARY OF BACKGROUND DATA

The treatment of SAIS is controversial and the opinion continues to remain divided between in situ fusion and reduction followed by stabilization. We reported a new surgical technique to facilitate safe reduction and stabilization of SAIS and the results in eight adolescents are presented.

METHODS

Eight patients with Meyerding Grade III (2), IV (5), and V(1) were operated between 2000 and 2006 for SAIS. The back/leg pain duration was 13.7 months and average age at surgery was 14.75 years. The slip angle (SA), percentage slip (%S), sacral inclination (SI), lumbar lordosis (LL), pelvic incidence (PI), and sagittal balance were measured and the Oswestry Disability Index (ODI) and visual analog scale pain score were used as outcome measures. All patients underwent posterior decompression with sacral dome osteotomy, anterior transperitoneal L5/S1 discectomy, and posterior reduction and instrumented circumferential fusion in a single operative session.

RESULTS

The average follow-up was 6 years. The mean preoperative degree of slip was 86%, which improved to 5% (r 1-17%, spondyloptosis case 32%) postoperatively. The mean L5 SA, SI, and LL preoperatively were 48°, 34°, and -72°, respectively, and postoperatively improved to 43° and -47°, respectively. The sagittal balance was 55 and 34 mm pre- and postoperatively, respectively. Near anatomical reduction was achieved in seven patients. No implant failures or revisions to date. The mean ODI improved to 6% from 56% and visual analog scale from 8 to 1, postoperatively.

CONCLUSION

This safe 3-stage procedure assists sudden reduction and circumferential fusion of SAIS without any neurologic deficit and excellent clinicoradiologic outcome restoring normal lumbosacral biomechanics.

High-grade child spondylolisthesis: a custom-made canulated screw to treat the so-called double instability

STUDY OBJECTIVES

Describing and assessing of a new surgical procedure to achieve circumferential fusion and translumbosacral fixation using a custom-made canulated screw.

PATIENTS AND METHODS

Seven patients aged 13-18 years old underwent surgery with this technique (mean age: 15). All patients had high-grade spondylolisthesis (Meyerding stage III or IV). There were five girls and two boys. A posterior surgical approach alone was used in all cases. The posterior neural arch of L5 was removed and a sacral laminectomy, extending to S2, was performed. Sacral nerve roots S2 and S3 were carefully dissected and transposed. A K-wire was placed medially across the vertebrae from the posterior edge of S2 extending to the anterosuperior corner of L5. Fluroscopic perioperative fluroscopic control confirmed correct K-wire placement. The custom-made 10mm diameter canulated screw was then inserted along the K-wire as a guide. Screw fixation was obtained by placing a specific large diameter screw head to obtain compression by a lag screw effect. Once fixation was obtained, the sacral dome was excised and interbody fusion was performed (tricorticocancellous graft on each side of the screw). Additional bilateral posterolateral fusion was then performed. A half body custom fit thoracolumbar orthosis brace was prescribed 3 months postoperatively, followed by a Lombostat flexible lumbar support for an additional 3 months period.

RESULTS

One neurological complication occurred. A dural tear occurred during dissection requiring simple repair. All of the patients were on their feet on the fifth postoperative day and began walking. The half bodybrace was worn for 4 months in four patients and 2 months in the three others. At final follow-up patients had no residual pain.

DISCUSSION

The lumbar spine in children with high-grade spondylolisthesis adapts to the new mechanical conditions after surgery. Therefore the principal goal of treatment is to obtain stable osseous fusion. Our treatment philosophy is based on the concept of a dual instability. We believe that a general instability exists which causes the development of spondylolisthesis; this must be respected by not attempting to correct the displacement beyond what can be obtained on the operating table with complete muscle release. The other, locoregional instability, must be stabilized during circumferential fusion. The custom-made, 10mm screw has been shown to be effective in neutralizing the mechanical stress during circumferential fusion with a posterior approach alone, thus avoiding the risks of an anterior approach. Long-term results show that the preoperative posture is not the sole mechanical determinant in children and adolescents but that this posture is largely a reaction to pain.

LEVEL OF EVIDENCE

Level IV. Retrospective study.

Transsacral screw fixation for high-grade spondylolisthesis

BACKGROUND CONTEXT

Symptomatic high-grade spondylolisthesis (Meyerding III-V) is usually treated by surgery. Recent literature shows that in situ fusion is better than reduction of the slip and fusion in high-grade spondylolisthesis. Furthermore, the outcome is improved if circumferential fusion is performed in severe spondylolisthesis. We have performed a new technique of circumferential fusion in high-grade spondylolisthesis using two transsacral hollow modular anchorage (HMA) screws supplemented with pedicle screw fixation and posterolateral fusion.

PURPOSE

The aim of the study is to analyze the results of circumferential fusion using transsacral HMA screws supplemented with posterolateral fusion and pedicle screw fixation.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

Twelve patients with high-grade spondylolisthesis were reviewed.

OUTCOME MEASURES

Outcome was measured using short form 36 (SF-36) and the ability to return to work at the most recent follow-up.

METHODS

All patients had interbody fusion using transsacral HMA screws filled with cancellous bone graft and supplemented with pedicle screw instrumentation and posterolateral fusion.

RESULTS

The male to female ratio was 2:1 with a mean age of 31 years (range 13-54 years). Eleven of 12 patients had disappearance of leg pain. There were no neurological complications in any of them. Circumferential fusion was achieved in all of them at a mean follow-up of 21 months. The average physical function score improved from 22.50+/-10.34 to 57.50+/-17.39 (p=.001, 95% confidence interval [CI] -44.48 to -25.52), whereas the average pain score improved from 22.22+/-13.40 to 61.11+/-15.35 (p=.001, 95% CI -51.12 to -26.66).

CONCLUSIONS

HMA screws avoid the complications associated with autologous cortical fibular strut graft and also are useful to promote interbody fusion, as the hollowness in the screw can be filled with cancellous bone graft that helps in better fusion. Supplementary pedicle screw fixation is necessary to protect the HMA screws, and they together give a stable construct that can achieve a circumferential fusion in high-grade spondylolisthesis.

Spino-pelvic alignment after surgical correction for developmental spondylolisthesis

This study is a retrospective multi-centre analysis of changes in spino-pelvic sagittal alignment after surgical correction of L5-S1 developmental spondylolisthesis. The purpose of this study was to determine how sagittal spino-pelvic alignment is affected by surgery, with the hypothesis that surgical correction at the lumbo-sacral level is associated with an improvement in the shape of the spine and in the orientation of the pelvis. Whether L5-S1 high grade spondylolisthesis should or should not be reduced remains a controversial subject. A popular method of treatment has been in situ fusion, but studies have reported a high rate of pseudarthrosis, slip progression and persistent cosmetic deformity. Spinal instrumentation with pedicle screws has generated a renewed interest for reduction, but the indications for this treatment and its effect on spino-pelvic alignment remain poorly defined. Recent evidence indicates that reduction might be indicated for subjects with an unbalanced (retroverted or vertical) pelvis. This is a retrospective multi-centre analysis of 73 subjects (mean age 18 +/- 3 years) with developmental spondylolisthesis and an average follow-up of 1.9 years after reduction and posterior fusion with spinal instrumentation or cast immobilisation. Spinal and pelvic alignment were measured on standing lateral digitised X-rays using a computer software allowing a very high inter and intra observer reliability. Pelvic incidence was unaffected by surgery. The most important changes were noted for grade, L5 Incidence, lumbo-sacral-angle, and lumbar lordosis, which all decreased significantly towards normal adult values. At first evaluation, pelvic tilt, sacral slope and thoracic kyphosis appeared minimally affected by surgery. However, after classifying subjects into balanced and unbalanced pelvis, significant improvements were noted in pelvic alignment in both the sub-groups, with 40% of cases switching groups, the majority from an unbalanced to a balanced pelvis alignment. The direction and magnitude of these changes were significantly different by sub-group: sacral slope decreased in the balanced pelvis group but increased in the unbalanced group, while pelvic tilt values did the opposite. While pelvic shape is unaffected by attempts at surgical reduction, proper repositioning of L5 over S1 significantly improves pelvic balance and lumbar shape by decreasing the abnormally high lumbar lordosis and abnormal pelvic retroversion. These results emphasise the importance of sub-dividing subjects with high grade developmental spondylolisthesis into unbalanced and balanced pelvis groups, and further support the contention that reduction techniques might be considered for the unbalanced retroverted pelvis sub-group.