Minimally invasive surgical options for adolescent idiopathic scoliosis

Minimally invasive surgery versus standard posterior approach in the treatment of adolescent idiopathic scoliosis: a 2-year follow-up retrospective study

PURPOSE

This is a monocentric retrospective controlled study that compares the safety and efficacy of posterior minimally invasive surgery (MISS) to standard posterior spinal fusion (PSF) surgery in adolescent idiopathic scoliosis (AIS).

METHODS

We retrospectively collected 111 patients with Lenke type 1-6 AIS who were treated with MIS (n = 47) or PSF (n = 64) between February 2019 and January 2021 with a 2-year clinical and radiological follow-up. MIS technique was applied via two midline noncontiguous skin incisions ranging from 3 to 7 cm in length, so we obtained the arthrodesis only in the exposed tract, passing the rods below the fascia, avoiding the complete muscular sparing. Values of Cobb angles degrees were collected to study the correction rate of the structural major curve. Postoperative AP direct radiography and preoperative AP direct radiography were compared with the last follow-up examination. Operative time, preoperative hemoglobin (Hb) and second postoperative day Hb, full length of hospitalization, time to achieve verticalization and time to remove the drainage were recorded. NRS medium score was assessed immediately after surgery and during the whole postoperative rehabilitation treatment to estimate pain reduction. Complications were collected postoperatively and throughout the whole follow-up period.

RESULTS

There was no significant difference between the two groups in terms of radiographic and clinical features. The correction rates of the structural curve resulted to be not significantly different between MISS and PSF (64.6 ± 11.7 vs 60.9 ± 13.2, p = 0.1292) as well as for the correction rate of the secondary curve between the two compared techniques (59.1 ± 13.2 vs 59.2 ± 12.4, p = 0.9865). The two groups had comparable operative time (210 min vs 215 min). The MIS group had a significantly lower reduction of postoperative Hb in comparison with PSF group (2.8 ± 1.3 mg/dl vs 4.3 ± 1.5 mg/dl, p < 0.0001). The postoperative NRS score was lower in MIS group (1.9 ± 0.8 vs 3.3 ± 1.3). PSF group was observed to have a significantly longer period of hospitalization than MIS (5.2 ± 1.4 days vs 6.3 ± 2.9 days, p = 0.206). Complications were more frequent in PSF group rather than in MFS group.

CONCLUSIONS

MISS is a safe and capable alternative to PSF for AIS patients with curves < 70°, with analogue capacity of scoliosis correction and same operative time and with advantages in blood loss, length of stay and postoperative pain.

Adolescent Idiopathic Scoliosis: Is the Feasible Option of Minimally Invasive Surgery using Posterior Approach?

The purpose of this systematic review and meta-analysis is to perform a systematic review and meta-analysis of previous studies on minimally invasive scoliosis surgery (MISS) in adolescents with idiopathic scoliosis (AIS). Some data on MISS in AIS compared with conventional open scoliosis surgery (COSS) are conflicting. A systematic literature search was conducted in Medline, Embase, and Cochrane Library, including studies reporting outcomes for MISS in AIS. The meta-analysis compared the operative, radiological, and clinical outcomes and complications between MISS and COSS in patients with AIS. Of the 208 records identified, 15 nonrandomized studies with 1,369 patients (reviews and case reports are excluded) were included in this systematic review and meta-analysis. The mean scale was 6.1, and eight of the 15 included studies showed satisfactory quality using the Newcastle-Ottawa scale. For operative outcomes, MISS had significant benefits in terms of estimated blood loss (standard mean difference [SMD], -1.87; 95% confidence interval [CI], -2.94 to -0.91) and hospitalization days (SMD, -2.99; 95% CI, -4.45 to -1.53) compared with COSS. However, COSS showed significantly favorable outcomes for operative times (SMD, 1.71; 95% CI, 0.92-2.51). No significant differences were observed in radiological outcomes, including Cobb's angle of the main curve and thoracic kyphosis. For clinical outcomes, MISS showed significant benefits on the visual analog scale score (SMD, -0.91; 95% CI, -1.36 to -0.47). The overall complication rates of MISS were similar to those of COSS (SMD, 0.96; 95% CI, 0.61-1.52). MISS using the posterior approach provides equivalent radiological and clinical outcomes and complication rates compared with COSS. Considering the lower estimated blood loss, shorter hospitalization days, and longer operative times in MISS, COSS is still the mainstay of surgical treatment in AIS; however, MISS using the posterior approach is also one of the surgical options of choice in the case of moderate AIS.

Minimally Invasive Surgery for Adolescent Idiopathic Scoliosis: A Systematic Review

Background: Minimally invasive surgical (MIS) techniques have gained popularity as a safe and effective alternative to open surgery for degenerative, traumatic, and metastatic spinal pathologies. In adolescent idiopathic scoliosis, MIS techniques comprise anterior thoracoscopic surgery (ATS), posterior minimally invasive surgery (PMIS), and vertebral body tethering (VBT). In the current systematic review, the authors collected and analyzed data from the available literature on MIS techniques in AIS. Methods: The articles were shortlisted after a thorough electronic and manual database search through PubMed, EMBASE, and Google Scholar. Results: The authors included 43 studies for the review; 14 described the outcomes with ATS, 13 with PMIS, and 16 with VBT. Conclusions: While the efficacy of the ATS approach is well-established in terms of comparable coronal and sagittal correction to posterior spinal fusion, the current use of ATS for instrumented fusion has become less popular due to a steep learning curve, high pulmonary and vascular complication rates, implant failures, and increased non-union rates. PMIS is an effective alternative to the standard open posterior spinal fusion, with a steep learning curve and longer surgical time being potential disadvantages. The current evidence, albeit limited, suggests that VBT is an attractive procedure that merits consideration in terms of radiological correction and clinical outcomes, but it has a high complication and re-operation rate, while the most appropriate indications and long-term outcomes of this technique remain unclear.

Single Long-Incision Minimally Invasive Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The objective of this study is to determine differences in outcomes in patients with adolescent idiopathic scoliosis undergoing spinal deformity correction surgery using a posterior spinal fusion (PSF) approach versus single and triple-incision minimally invasive surgery (MIS).

SUMMARY OF BACKGROUND DATA

MIS increased in popularity as surgeons' focus moved towards soft tissue preservation, but it carries technical demands and increased surgical time compared with PSF.

PATIENTS AND METHODS

Surgeries performed from 2016 to 2020 were included. Cohorts were formed based on surgical approach: PSF versus single long-incision MIS (SLIM) versus traditional MIS [3-incision MIS (3MIS)]. There were a total of 7 subanalyses. Demographic, radiographic, and perioperative data were collected for the 3 groups. Kruskal-Wallis and χ 2 tests were used for continuous and categorical variables, respectively.

RESULTS

Five hundred thirty-two patients met our inclusion criteria, 294 PSF, 179 3MIS, and 59 SLIM.Estimated blood loss (mL) ( P < 0.00001) and length of stay (LOS) ( P < 0.00001) was significantly higher in PSF than in SLIM and 3MIS. Surgical time was significantly higher in 3MIS than in PSF and SLIM ( P = 0.0012).Patients who underwent PSF had significantly lower postoperative T5 to T12 kyphosis ( P < 0.00001) and percentage kyphosis change ( P < 0.00001). Morphine equivalence was significantly higher in the PSF group during total hospital stay ( P = 0.0042).Patients who underwent SLIM and 3MIS were more likely to return to noncontact ( P = 0.0096) and contact sports ( P = 0.0095) within 6 months and reported lower pain scores ( P < 0.001) at 6 months postoperation.

CONCLUSION

SLIM has a similar operative time to PSF and is technically similar to PSF while maintaining the surgical and postoperative outcome advantages of 3MIS.

Minimally Invasive Surgery for Posterior Spinal Instrumentation and Fusion in Adolescent Idiopathic Scoliosis: Current Status and Future Application

The posterior minimally invasive spine surgery (MISS) approach-or the paraspinal muscle approach-for posterior spinal fusion and segmental instrumentation in adolescent idiopathic scoliosis (AIS) was first reported in 2011. It is less invasive than the traditionally used open posterior midline approach, which is associated with significant morbidity, including denervation of the paraspinal muscles, significant blood loss, and a large midline skin incision. The literature suggests that the MISS approach, though technically challenging and with a longer operative time, provides similar levels of deformity correction, lower intraoperative blood loss, shorter hospital stays, better pain outcomes, and a faster return to sports than the open posterior midline approach. Correction maintenance and fusion rates also seem to be equivalent for both approaches. This narrative review presents the results of relevant publications reporting on spinal segmental instrumentation using pedicle screws and posterior spinal fusion as part of an MISS approach. It then compares them with the results of the traditional open posterior midline approach for treating AIS. It specifically examines perioperative morbidity and radiological and clinical outcomes with a minimal follow-up length of 2 years (range 2-9 years).

Evaluating the Use of PROMs in Paediatric Orthopaedic Registries

Patient-reported outcome measures (PROMs) provide structured information on the patient's health experience and facilitate shared clinical decision-making. Registries that collect PROMs generate essential information about the clinical course and efficacy of interventions. Whilst PROMs are increasingly being used in adult orthopaedic registries, their use in paediatric orthopaedic registries is not well known. The purpose of this systematic review was to identify the frequency and scope of registries that collect PROMs in paediatric orthopaedic patient groups. In July 2023, six databases were systematically searched to identify studies that collected PROMs using a registry amongst patients aged under 18 years with orthopaedic diagnoses. Of 3190 identified articles, 128 unique registries were identified. Three were exclusively paediatric, 27 were majority paediatric, and the remainder included a minority of paediatric patients. One hundred and twenty-eight registries collected 72 different PROMs, and 58% of these PROMs were not validated for a paediatric population. The largest group of orthopaedic registries collected PROMs on knee ligament injuries (21%). There are few reported dedicated orthopaedic registries collecting PROMs in paediatric populations. The majority of PROMs collected amongst paediatric populations by orthopaedic registries are not validated for patients under the age of 18 years. The use of non-validated PROMs by registries greatly impedes their utility and impact. Dedicated orthopaedic registries collecting paediatric-validated PROMs are needed to increase health knowledge, improve decision-making between patients and healthcare providers, and optimise orthopaedic management.

Paraspinal muscle approach for neuromuscular scoliosis: A comparative study evaluating deformity correction and perioperative morbidity in 91 patients with minimum 2-year follow-up

PURPOSE

We present the paraspinal approach use for neuromuscular scoliosis with focus on deformity correction, perioperative (≤30 days) morbidity and outcome at a minimal follow-up length of 2 years.

METHODS

We prospectively collected data of 61 neuromuscular scoliosis patients operated using a paraspinal (Wiltse) approach between 2013 and 2019. We additionally collected data of 104 control cases, operated using a midline approach between 2005 and 2016. Fifteen Wiltse, respectively 37 control patients were excluded due to a short follow-up (<2 years), and 22 controls were excluded secondary to lacking follow-up data. Hence, 46 Wiltse and 45 control patients were compared.

RESULTS

Wiltse and control patients had comparable follow-up lengths, demographics, deformity corrections, complication rates, number of levels fused, and intensive care unit and hospital lengths of stay. Wiltse cases had a lower estimated blood loss (535 vs 1187 mL; p-value < 0.001), allogenic transfusion rate (48% vs 96%; p-value < 0.001), and operating time (ORT) (337 vs 428 min; p-value < 0.001) than controls. This was also the case when selecting for patients without pelvic fixation (p-values < 0.001). When selecting the cases with pelvic fixation (20 among 91 cases), only the number of levels fused and the ORT differed significantly according to the approach (p-value <0.015 and <0.041).

CONCLUSION

The paraspinal approach for neuromuscular scoliosis is safe, associated with significant deformity correction, reduced estimated blood loss, and allogenic transfusion rate. These potential benefits still need to be evaluated, especially for cases with pelvic fixation, with further follow-up of larger cohorts.

LEVEL OF EVIDENCE

level III.

Novel Surgical Technique for Adolescent Idiopathic Scoliosis: Minimally Invasive Scoliosis Surgery

Despite advancements in instruments and surgical techniques for adolescent idiopathic scoliosis (AIS) surgery, conventional open scoliosis surgery (COSS) is usually required to achieve satisfactory deformity correction using various distinct surgical techniques, such as rod derotation, direct vertebral rotation, facetectomies, osteotomies, and decortication of the laminae. However, COSS is accompanied by significant blood loss and requires a large midline skin incision. Minimally invasive surgery (MIS) has evolved enormously in various fields of spinal surgery, including degenerative spinal diseases. MIS of the spine has some advantages over conventional surgery, such as a smaller incision, less blood loss and postoperative pain, and lower infection rates. Since the introduction of MIS for AIS in 2011, MIS has been reported to have comparable outcomes, including correction rate with some usual advantages of MIS. However, several complications, such as dislodgement of rods, wound infection, and hypertrophic scar formation, have also been reported in the initial stages of MIS for AIS. We devised a novel approach, called the coin-hole technique or minimally invasive scoliosis surgery (MISS), to minimize these complications. This article aimed to introduce a novel surgical technique for AIS and provide a preliminary analysis and up-to-date information regarding MISS.

Minimally invasive surgery using posterior-only Pedicle screw fixation in treatment of Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-Analysis

Minimally invasive surgery (MIS) techniques for posterior spine pedicle-screw fusion (PSF) may reduce the AIS surgery invasiveness, although they require a certain degree of patient selection based on the severity of the curve. The aim of this article is to systematically review the Literature to determine efficacy and safety of MIS-PSF in AIS correction, and to compare its outcomes with open-PSF. A systematic search of electronic databases from eligible articles was conducted. Only studies adopting MIS-PSF for AIS were included. Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed. P-value < 0.05 was considered significant. Thirteen studies for a total of 635 patients ungergoing MIS-PSF were included in this review. Pre-operative Cobb's angle ranged from 48.3°±4.2° to 59.8°±6.6°, coronal correction from 58.1% to 79.1%, average operative time ranged from 252 to 526.8 min, average estimated blood loss from 138.8 ± 50 to 1250 mL. Sixty-seven complications were recorded (9.9%), with 19 revisions (3.8%), resulting similar to those described in Literature using open-PSF. At meta-analysis, MIS-PSF (321 patients) compared to open-PSF (429 patients) showed lower coronal correction (although no statistically significant difference was found), estimated blood loss and length of hospital stay, but higher operative time. No differences in SRS-22, complications and revision rate were found. In conclusion, open-PSF shows a trend towards higher correction in the coronal plane and requires a shorter operative time when compared to MIS-PSF. It remains the gold standard for AIS correction, although MIS-PSF seems to be a viable and promising technique for selected patients. - KEYWORDS: minimally invasive surgery, minimally invasive techniques, adolescent idiopathic scoliosis, posterior spinal fusion, pedicle-screws-only instrumentation.

Posterior minimally invasive scoliosis surgery versus the standard posterior approach for the management of adolescent idiopathic scoliosis: an updated meta-analysis

Background

Surgical management of adolescent idiopathic scoliosis (AIS) can be performed using standard posterior spinal fusion (PSF) or with a posterior minimally invasive approach. Minimally invasive scoliosis surgery (MISS) has several theoretical advantages, such as less tissue dissection, less blood loss, and earlier recovery. However, the difference in safety and effectiveness between MISS and PSF still needs to be clarified. This updated meta-analysis aimed to compare the outcomes of MISS and standard PSF for the management of AIS.

Methods

A comprehensive literature search of PubMed, EMBASE, MEDLINE, and Cochrane Library without time restriction was performed to identify relevant studies. MISS and PSF were compared in terms of radiographic parameters, estimated blood loss (EBL), blood transfusion rate, operative time (ORT), length of hospital stay (LOS), overall Scoliosis Research Society-22 (SRS-22) score, postoperative pain, and complication rate.

Results

A total of seven studies comprising 767 patients (329 MISS and 438 PSF) with AIS were included. MISS and PSF yielded comparable deformity correction at the last follow-up. There were no significant differences in the overall SRS-22 scores or complication rates between the groups. Nevertheless, greater restoration of thoracic kyphosis (WMD, 2.98; 95% CI 0.58 to 5.37, P = 0.015), less EBL (WMD, −218.76; 95% CI −256.41 to −181.11, P < 0.001), a lower blood transfusion rate (RR, 0.31; 95% CI 0.20 to 0.48, P < 0.001), a shorter LOS (WMD, −1.48; 95% CI −2.48 to −0.48, P = 0.004), less postoperative pain (WMD, 0.57; 95% CI 0.16 to 0.98, P = 0.006), and a longer ORT (WMD, 84.85; 95% CI 33.30 to 136.40, P = 0.001) were observed in the MISS group.

Conclusion

Despite its inherent technical challenges, MISS is a feasible and effective alternative to standard PSF for AIS patients with moderate and flexible curves. MISS was associated with adequate deformity correction, better restoration of sagittal alignment, less EBL, fewer transfusions, shorter LOS, and better pain management compared to PSF. Further research is required to determine the detailed indications for the MISS procedure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02954-4.

Minimally Invasive Surgery versus Open Surgery for Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-Analysis

Minimally invasive surgery (MIS) is being recommended over more invasive methods. MIS advantages are less time in the operating room, less blood loss, a shorter recovery time, and shorter length of stay. A systematic review and meta-analysis were performed using the literature from minimally invasive and open surgery for adolescent idiopathic scoliosis (AIS). We conducted this analysis to see whether MIS has advantages over traditional surgery. A systematic review was conducted using PubMed, Embase, and Scopus to find articles comparing minimally invasive and open surgery techniques for AIS patients. Data extraction and meta-analysis were completed. The primary data points collected were correction rate and functional outcomes, including perioperative and postoperative parameters. A total of six studies were included in the final analysis. The MIS group had 123 patients, and the open surgery group had 150 patients. The correction rate and functional outcomes favored the open surgery group with a mean difference of 4.60 (95% confidence interval [CI], 0.08 to 9.12) and 0.11 (95% CI, 0.04 to 0.17), respectively. The duration of surgery, blood loss, number of patients requiring transfusion, and analgesic requirements favored the MIS group with a significant difference. Open surgery is better than MIS in achieving a better correction rate and good functional outcomes. MIS is better over open surgery when perioperative parameters are considered.

Clinical and radiological outcomes of minimally-invasive surgery for adolescent idiopathic scoliosis at a minimum two years' follow-up

AIMS

The direct posterior approach with subperiosteal dissection of the paraspinal muscles from the vertebrae is considered to be the standard approach for the surgical treatment of adolescent idiopathic scoliosis (AIS). We investigated whether or not a minimally-invasive surgery (MIS) technique could offer improved results.

METHODS

Consecutive AIS patients treated with an MIS technique at two tertiary centres from June 2013 to March 2016 were retrospectively included. Preoperative patient deformity characteristics, perioperative parameters, power of deformity correction, and complications were studied. A total of 93 patients were included. The outcome of the first 25 patients and the latter 68 were compared as part of our safety analysis to examine the effect of the learning curve.

RESULTS

In the first 25 cases, with a mean follow-up of 5.6 years (standard deviation (SD) 0.4), the mean preoperative major Cobb angle was 57.6° (SD 9.8°) and significantly corrected to mean 15.4° (SD 5.6°, 73% curve correction). The mean preoperative T5-T12 was 26.2 (SD 12.8) and significantly increased to mean 32.9 (SD 8.3). Both frontal and sagittal plane correction was conserved two years after surgery. The rate of perioperative complications was 12% and three further complications occurred (three deep delayed infection). In the latter cases, 68 patients were included with a mean follow-up time of three years (SD 0.6). The mean preoperative major Cobb angle was 58.4° (SD 9.2°) and significantly corrected to mean 20.4° (SD 7.3°).The mean preoperative T5-T12 kyphosis was 26.6° (SD 12.8°) and was significantly increased to mean 31.4° (SD 8.3°). Both frontal and sagittal correction was conserved two years after surgery. The perioperative (30 day) complication rate was 1.4%. Two (2.9%) additional complications occurred in two patients.

CONCLUSION

MIS for AIS is associated with a significant correction of spine deformity in the frontal and sagittal planes, together with low estimated blood loss and short length of stay. The perioperative complication rate seems to be lower compared with the standard open technique based on the literature data. The longer-term safety of MIS for AIS needs to be documented with a larger cohort and compared with the standard posterior approach. Cite this article: Bone Joint J 2020;102-B(4):506-512.

Safety and effectiveness of minimally invasive scoliosis surgery for adolescent idiopathic scoliosis: a retrospective case series of 84 patients

PURPOSE

The aim of this study was to retrospectively evaluate a prospective series of patients with adolescent idiopathic scoliosis (AIS) who were treated with minimally invasive scoliosis surgery (MISS) technique with a minimum follow-up more than 1 year.

MATERIALS AND METHODS

We retrospectively analyzed the prospectively collected data of 84 patients with AIS treated with MIS technique using two or three coin hole size incisions and a muscle-splitting approach. The clinical and radiological data such as the correction of deformity, coronal and sagittal profile and record of the perioperative morbidity of the patients were analyzed.

RESULTS

The mean primary Cobb angle was corrected from 59.8° preoperatively to 18.6° postoperatively with a mean correction of 68.9% (p < 0.001). The mean kyphosis at T2 to T12 was maintained within normal range with an increase from 31.2° preoperatively to 35.3° postoperatively (p < 0.001). The 30-day perioperative complication rate was 7.14% with one deep infection and five cases of hemothorax. The mean operation time was 312.8 min; mean estimated blood loss was 846.6 ml (range 420-2800); and mean length of stay was 8.5 days (range 5 to 14). All data of postoperative SRS-22 questionnaire were significantly improved (p < 0.001).

CONCLUSION

MISS used for AIS provides adequate correction in both planes and acceptable rate of perioperative complications, with a low estimated blood loss and short length of stay. Considering all the positives, the application of MISS technique for AIS seems meaningful and can become a valid alternative to posterior approach in the routine use. These slides can be retrieved under Electronic Supplementary Material.

Minimal invasive posterior correction of Lenke 5C idiopathic scoliosis: comparative analysis of minimal invasive vs. open surgery

INTRODUCTION

Surgical management of adolescent idiopathic scoliosis in spite of usually favourable outcomes is still a major operation. Therefore, efforts are being undertaken to minimalize the procedure, reduce the surgical trauma and postoperative convalescence. The study was designed to compare posterior minimal invasive surgery using navigation based on intraoperative 3D imaging and standard open instrumented fusion in Lenke 5C idiopathic scoliosis treatment.

MATERIALS AND METHODS

From eight patients with Lenke 5C curves planned for posterior correction and instrumented fusion, four were treated with minimally invasive and four had open procedure. Operation length, estimated blood loss, number of fusion levels, days of opioid intake, length of hospital stay and radiation doses required were noted. Radiographic assessment of spinal curvatures was performed (magnitude, flexibility, sagittal alignment). The comparison of the data was done between open and minimally invasive treated patients.

RESULTS

In minimally invasive surgery group, the operations were longer on average 285 min ± 47.5 than in the open surgery group, 242.5 min ± 44.5 (p = 0.371) and resulted in slightly inferior coronal curve correction by 68.25% ± 6.2 vs. 78.25% ± 8.8, respectively (p = 0.072). We observed a clear reduction of intraoperative blood loss in minimally invasive patients (mean 138.75 ± 50 vs. 450 ± 106 ml, p = 0.016), shorter hospital stay, average 3.75 vs. 7 days (p = 0.043) and lower opioid requirements postoperatively - 2 vs. 3.25 days (p = 0.015).

CONCLUSIONS

The minimally invasive approach to idiopathic scoliosis treatment is a very promising technique to limit the extent of surgery maintaining the same goals as in the open method. It allows for lower blood loss, less requirement for opioids and a shorter hospital stay.

Pseudarthrosis in adult and pediatric spinal deformity surgery: a systematic review of the literature and meta-analysis of incidence, characteristics, and risk factors

We conducted a systematic review with meta-analysis and qualitative synthesis. This study aims to characterize pseudarthrosis after long-segment fusion in spinal deformity by identifying incidence rates by etiology, risk factors for its development, and common features. Pseudarthrosis can be a painful and debilitating complication of spinal fusion that may require reoperation. It is poorly characterized in the setting of spinal deformity. The MEDLINE, EMBASE, and Cochrane databases were searched for clinical research including spinal deformity patients treated with long-segment fusions reporting pseudarthrosis as a complication. Meta-analysis was performed on etiologic subsets of the studies to calculate incidence rates for pseudarthrosis. Qualitative synthesis was performed to identify characteristics of and risk factors for pseudarthrosis. The review found 162 articles reporting outcomes for 16,938 patients which met inclusion criteria. In general, the included studies were of medium to low quality according to recommended reporting standards and study design. Meta-analysis calculated an incidence of 1.4% (95% CI 0.9-1.8%) for pseudarthrosis in adolescent idiopathic scoliosis, 2.2% (95% CI 1.3-3.2%) in neuromuscular scoliosis, and 6.3% (95% CI 4.3-8.2%) in adult spinal deformity. Risk factors for pseudarthrosis include age over 55, construct length greater than 12 segments, smoking, thoracolumbar kyphosis greater than 20°, and fusion to the sacrum. Choice of graft material, pre-operative coronal alignment, post-operative analgesics, and sex have no significant impact on fusion rates. Older patients with greater deformity requiring more extensive instrumentation are at higher risk for pseudarthrosis. Overall incidence of pseudarthrosis requiring reoperation is low in adult populations and very low in adolescent populations.

Minimally invasive surgery for adolescent idiopathic scoliosis

Aims

The aim of this study was to report a retrospective, consecutive series of patients with adolescent idiopathic scoliosis (AIS) who were treated with posterior minimally invasive surgery (MIS) with a mean follow-up of two years (sd 1.4; 0.9 to 0 3.7). Our objectives were to measure the correction of the deformity and record the peri-operative morbidity. Special attention was paid to the operating time (ORT), estimated blood loss (EBL), length of stay (LOS) and further complications.

Patients and Methods

We prospectively collected the data of 70 consecutive patients with AIS treated with MIS using three incisions and a muscle-splitting approach by a single surgeon between June 2013 and February 2016 and these were retrospectively reviewed. There were eight male and 62 female patients with a mean age of 15 years (sd 4.5 ) with a mean body mass index of 19.8 kg/m2 (sd 5.4). The curves were classified according to Lenke; 40 curves were type 1, 15 were type 2, three were type 3, two were type 4, eight were type 5 and two were type 6.

Results

The mean primary Cobb angle was corrected from 58.9° (sd 12.6°) pre-operatively to 17.7° (sd 10.2°) post-operatively with a mean correction of 69% (sd 20%, p < 0.001). The mean kyphosis at T5 to T12 increased from 24.2° (sd 12.2°) pre-operatively to 30.1° (sd 9.6°, p < 0.001) post-operatively. Peri-operative (30 days) complications occurred in three patients(4.2%): one subcutaneous haematoma, one deep venous thrombosis and one pulmonary complication. Five additional complications occurred in five patients (7.1%): one superficial wound infection, one suture granuloma and three delayed deep surgical site infections. The mean ORT was 337.1 mins (sd 121.3); the mean EBL was 345.7 ml (sd 175.1) and the mean LOS was 4.6 days (sd 0.8).

Conclusion

The use of MIS for patients with AIS results in a significant correction of spinal deformity in both the frontal and sagittal planes, with a low EBL and a short LOS. The rate of peri-operative complications compares well with that following a routine open technique. The longer term safety and benefit of MIS in these patients needs to be evaluated with further follow-up of a larger cohort of patients. Cite this article: Bone Joint J 2017;99-B:1651–7.

Minimally invasive surgery in the treatment of adolescent idiopathic scoliosis: A literature review and meta-analysis

BACKGROUND CONTEXT

Spinal fusion surgery for scoliosis can be performed using a traditional open approach, or by following a minimally invasive approach. Minimally invasive surgery (MIS) is associated with theoretical advantages, such as reduced blood loss and a shorter hospital stay, yet there is no consensus in the literature with regard to the best treatment approach for adolescent idiopathic scoliosis (AIS).

PURPOSE

To assess the clinical outcomes of patients with AIS treated with either an open or minimally invasive approach.

STUDY DESIGN

Systematic review and meta-analysis of English-language studies for the treatment of adolescent idiopathic scoliosis.

PATIENT SAMPLE

Pooled results from level 1 and 2 studies.

METHODS

We carried out a systematic literature search of EMBASE and MEDLINE, identifying studies investigating MIS in the treatment of AIS. Percentages of curvature correction were pooled and analysed.

RESULTS

The literature search returned 50 articles, of which we determined 4 studies to be relevant. The pooled percentage curve correction across these groups was 62.05% for the MIS group and 70% for the open surgery group. Although these data are significant (p = 0.001), the available studies are of variable quality, and sample sizes small.

CONCLUSIONS

Patients with adolescent idiopathic scoliosis can be managed with either a traditional open approach or a minimally invasive approach. The data suggests that open surgery offers an advantage in terms of curve correction, compared to minimally invasive surgery, however more investigation (in the form of robust randomized control trials) is needed before conclusive clinical suggestions can be recommended.

Robotic-assisted minimally invasive surgery of the spine (RAMISS): a proof-of-concept study using carbon dioxide insufflation for multilevel posterior vertebral exposure via a sub-paraspinal muscle working space

BACKGROUND

Open posterior spinal procedures involve extensive soft tissue disruption, increased hospital length of stay, and disfiguring scars. Our aim was to demonstrate the feasibility of using robotic-assistance for minimally invasive exposure of the posterolateral spine with and without carbon dioxide (CO₂ ) insufflation.

METHODS

Sheep specimens underwent minimally invasive subperiosteal dissection of the spine during three trials. The da Vinci S Surgical system was used for access with and without working space support via CO₂ insufflation.

RESULTS

Without insufflation, a sub-paraspinal muscle tunnel measuring 16 cm was developed between two 5 cm incisions. With insufflation, the one-sided tunnel length was 12.5 cm but without the soft tissue trauma and obstructed visualization experienced without CO₂ .

CONCLUSIONS

The use of robot-assistance for minimally invasive access to the posterior spine appears to be feasible. The use of CO₂ insufflation greatly improved our ability to visualize and access the posterior vertebral elements.