Sheila Kahwaty

Long-term 2- to 5-year clinical and functional outcomes of minimally invasive surgery for adult scoliosis.

Study Design. A retrospective study. Objective. We assess MIS techniques clinical and functional outcomes during a 2- to 5-year period. Summary of Background Data. Traditional surgical approaches for adult scoliosis are associated with significant blood loss and morbidity, in a population that is often elderly with multiple medical comorbidities. Minimally invasive surgery (MIS) represents a newer method of achieving similar long-term outcomes but considerably lower morbidity and complication rates. Methods. We reviewed 71 patients who underwent MIS correction of spinal deformity with fusion of 2 or more levels including: degenerative scoliosis (54), idiopathic scoliosis (11), and iatrogenic scoliosis (6). All underwent a combination of 3 MIS techniques: direct lateral interbody fusion (66), axial lumbar interbody fusion (34), and posterior instrumentation (67). Thirty-six patients were staged with direct lateral interbody fusion done first followed by the posterior instrumentation and fusion including axial lumbar interbody fusion done 3 days later. Results. Mean age was 64 years (20–84 yr). Mean follow-up was 39 months (24–60 mo). Patients with 1-stage same-day surgery had a mean blood loss of 412 mL and a mean surgical time of 291 minutes. Patients with 2-stage surgery had a mean blood loss of 314 mL and surgical time of 183 minutes for direct lateral interbody fusion and 357 mL and 243 minutes, respectively for posterior instrumentation and axial lumbar interbody fusion. Mean hospital stay was 7.6 days (2–26 d). The mean preoperative Cobb angle was 24.7° (8.3°–65°), which corrected to 9.5° (0.6°–28.8°). Mean preoperative Coronal balance was 25.5 mm, which corrected to 11 mm. Mean preoperative sagittal balance was 31.7 mm and corrected to 10.7 mm. The mean preoperative lumbar apical vertebral translation was 24 mm and corrected to 12 mm. Fourteen patients had adverse events requiring intervention: 4 pseudarthrosis, 4 persistent stenosis, 1 osteomyelitis, 1 adjacent segment discitis, 1 late wound infection, 1 proximal junctional kyphosis, 1 screw prominence, 1 idiopathic cerebellar hemorrhage, and 2 wound dehiscence. Conclusion. A combination of 3 novel MIS techniques allows comparable correction of adult spinal deformity, with low pseudarthrosis rates, significantly improved functional outcomes, and excellent clinical and radiological improvement, but considerably lowers morbidity and complication rates at early and long-term follow-up.

Evidence Basis/Outcomes in Minimally Invasive Spinal Scoliosis Surgery

Traditional adult scoliosis surgery is associated with long-term patient improvement in clinical and radiographic outcome measures, significant blood loss, and high likelihood of medical complications. Because the patient population undergoing adult scoliosis surgery is often elderly with medical comorbidities, minimally invasive spinal surgery (MISS) for adult scoliosis is theoretically appealing, because it is associated with less tissue trauma and reduced blood loss. Nevertheless, limitations exist with current techniques as far as the achievable degree of coronal and sagittal plane deformity correction. MISS scoliosis correction is reviewed, specifically regarding outcomes and complications. Limitations of current techniques and future directions are discussed.

Comparison of a Newer Versus Older Protocol for Circumferential Minimally Invasive Surgical (CMIS) Correction of Adult Spinal Deformity (ASD)—Evolution Over a 10-Year Experience

STUDY DESIGN Retrospective. OBJECTIVES Compare circumferential minimally invasive surgical (CMIS) correction outcomes of patients treated for adult spinal deformity (ASD) with a newer versus older protocol CMIS techniques have become increasingly popular. Increasing experience and learning curve may help improve outcomes. METHODS A prospectively collected database was queried for all patients who underwent CMIS correction of ASD (Cobb angle >20° or sagittal vertical axis [SVA] >50 mm or pelvic incidence-lumbar lordosis mismatch >10) at 3+ levels. Those without a full-length radiograph or 2-year follow-up were excluded. Patients were compared based on treatment using our original or newer protocol. RESULTS The original protocol had 76 patients with an average age of 66.99 years (range 46-81, standard deviation [SD] 9.03), and the new protocol had 53 patients with average age of 65.85 years (range 48-85, SD 8.08). Preoperative and latest visual analog scale (VAS) scores in the original were 6.85 and 3.45 (p = .001) and in the new were 6.19 and 2.27 (p = .004). Delta-VAS scores were 3.27 and 4.27. The Oswestry disability index (ODI) reduced from 45.84 to 32.91 (p = .041) in the original and from 44.21 to 25.39 (p = .017) in the new. Average delta-ODIs were 22.25 and 24.01. Preoperative, latest, and delta-SF physical component scores for the original were 35.38, 42.42, and 10.06 and for the new, 30.89, 39.49, and 11.93. SF mental component scores were 50.96, 55.19, and 12.84 and 50.12, 52.99, and 8.85. The original and new protocols had latest Cobb angles of 11.54° and 11.12° (p = .789), delta-Cobb angles of 14.51° and 20.03° (p < .05), latest SVAs of 42.85 and 30.58 mm (p < .05) and latest PI-LL mismatch of 15.49 and 9.00 mm (p <.05). In the original and the new, the average preoperative SVAs that reliably achieved a postoperative SVA of 50 mm or less were 84 and 119 mm, respectively, and the maximum delta-SVAs were 89 and 120 mm. The new protocol had fewer surgical complications (p < .05). CONCLUSION Improvements in radiographic scores, functional outcomes, and limits of SVA correction and lower complication rates suggest that the new protocol may help improve outcomes. These findings may be a reflection of our 10-year experience and advances in the learning curve. LEVEL OF EVIDENCE Level IV.STUDY DESIGN Retrospective. OBJECTIVES Compare circumferential minimally invasive surgical (CMIS) correction outcomes of patients treated for adult spinal deformity (ASD) with a newer versus older protocol SUMMARY OF BACKGROUND DATA: CMIS techniques have become increasingly popular. Increasing experience and learning curve may help improve outcomes. METHODS A prospectively collected database was queried for all patients who underwent CMIS correction of ASD (Cobb angle >20° or sagittal vertical axis [SVA] >50 mm or pelvic incidence-lumbar lordosis mismatch >10) at 3+ levels. Those without a full-length radiograph or 2-year follow-up were excluded. Patients were compared based on treatment using our original or newer protocol. RESULTS The original protocol had 76 patients with an average age of 66.99 years (range 46-81, standard deviation [SD] 9.03), and the new protocol had 53 patients with average age of 65.85 years (range 48-85, SD 8.08). Preoperative and latest visual analog scale (VAS) scores in the original were 6.85 and 3.45 (p = .001) and in the new were 6.19 and 2.27 (p = .004). Delta-VAS scores were 3.27 and 4.27. The Oswestry disability index (ODI) reduced from 45.84 to 32.91 (p = .041) in the original and from 44.21 to 25.39 (p = .017) in the new. Average delta-ODIs were 22.25 and 24.01. Preoperative, latest, and delta-SF physical component scores for the original were 35.38, 42.42, and 10.06 and for the new, 30.89, 39.49, and 11.93. SF mental component scores were 50.96, 55.19, and 12.84 and 50.12, 52.99, and 8.85. The original and new protocols had latest Cobb angles of 11.54° and 11.12° (p = .789), delta-Cobb angles of 14.51° and 20.03° (p < .05), latest SVAs of 42.85 and 30.58 mm (p < .05) and latest PI-LL mismatch of 15.49 and 9.00 mm (p < .05). In the original and the new, the average preoperative SVAs that reliably achieved a postoperative SVA of 50 mm or less were 84 and 119 mm, respectively, and the maximum delta-SVAs were 89 and 120 mm. The new protocol had fewer surgical complications (p < .05). CONCLUSION Improvements in radiographic scores, functional outcomes, and limits of SVA correction and lower complication rates suggest that the new protocol may help improve outcomes. These findings may be a reflection of our 10-year experience and advances in the learning curve. LEVEL OF EVIDENCE Level IV.

The Influence of Lordotic cages on creating Sagittal Balance in the CMIS treatment of Adult Spinal Deformity

Background CMIS techniques are heavily dependent on placement of lateral interbody cages. Cages with an increased lordotic angle are being advocated to improve segmental lordosis and SVA. We assessed the segmental lordosis achieved with the individual cages. We further studied three variables and the effect each had on segmental lordosis: the lordosis angle of the cage, the position of the cage in the intervertebral space, and the level that it has been placed. Methods This is a retrospective study of 66 consecutive patients who underwent lateral interbody fusion using lordotic cages as part of CMIS correction of scoliosis from June 2012 to January 2016. Standing radiographs at pre op and 6-week follow-up were reviewed to identify the position of the cage in the intervertebral space and the amount of segmental lordosis achieved. Results A total of 224 cages were placed. The 6°, 10°, 12°, and 20° cages achieved a mean segmental lordosis of 9.00°, 13.09°, 13.23°, and 18.32°, respectively (P < .05). Additionally, cages placed in the anterior, middle, and posterior 3rd of the disk space produced 13.02°, 11.47°, and 8.23° of lordosis, respectively (P < .05). Stratifying by level, cages placed at T12-L1, L1-2, L2-3, L3-4, and L4-5 translated to mean segmental lordotic values of 8.43°, 10.02°, 11.38°, 12.91°, and 14.58°, respectively (P < .05). Conclusions The angle of the cage had an impact on segmental lordosis. Achieved segmental lordosis was notably more when the cage was placed in lower lumbar levels. Additionally, cages placed in the posterior 3rd of the intervertebral space had significantly worse segmental lordosis compared to those placed in the anterior or middle 3rd. Our study shows that an average delta change of 8.03° can be achieved with 12° cages and this when done at each subsequent level results in a progressive harmonious creation of lordosis. IRB approval was obtained for this study.

Thirty-Day Reoperation and Readmission Rates After Correction of Adult Spinal Deformity via Circumferential Minimally Invasive Surgery—Analysis of a 7-Year Experience

STUDY DESIGN Single-center retrospective analysis of consecutive patients who have undergone circumferential minimally invasive surgery (cMIS) for correction of adult spinal deformity (ASD). OBJECTIVES To study the rates of reoperations and readmissions within the first 30 days following cMIS for correction of ASD. BACKGROUND Hospital readmission and reoperation rates have been emphasized as an important measure of quality and cost-effectiveness of care. However, there is little information about the readmission rates following cMIS correction of ASD. METHODS This is a retrospective cohort study of 214 consecutive patients with ASD who underwent correction using cMIS involving at least 2 levels. Major complications encountered during surgery or within 30 days following the index procedure that needed reoperation or readmission were recorded. The primary outcomes measured were early readmission, and early reoperation. RESULTS An average of 4 levels were fused. Nineteen complications were noted in the 30-day period following the index surgery, giving an early complication rate of 8.9%. Twelve of those complications occurred during the initial hospitalization and 7 complications occurred after the patient had been discharged home. Forty-seven percent of the complications occurred within the first 3 years of our experience, 37% in the next 2 years, and only 16% in the following 3 years. The 30-day readmission rate was 3.3%, which showed no statistically significant difference based on the number of levels fused. CONCLUSIONS Our study delivers significant evidence that efforts to reduce hospital readmissions for ASD patients should begin by concentrating on the postoperative complications. Although minimally invasive approaches will not eliminate all complications, they may have an effect on reducing the rate of major complications, most notably the rate of postoperative infection. This in turn can lead to a substantially lower readmission and reoperation rate as is reported in our study. LEVEL OF EVIDENCE Level IV, case series.