Frank L. Acosta Jr., Jeffrey Lotz, and Christopher P. Ames
Low-back pain is the most common health problem for men and women between 20 and 50 years of age, resulting in 13 million doctor visits in the US annually, with significant costs to society in terms of lost time from work and direct and indirect medical expenses. Although the exact origin of most cases of low-back pain remains unknown, it is understood that degenerative damage to the intervertebral disc (IVD) plays a central role in the pathogenic mechanism leading to this disorder. Current treatment modalities for disc-related back pain (selective nerve root blocks, surgical discectomy and fusion) are costly procedures aimed only at alleviating symptoms. Consequently, there is growing interest in the development of novel technologies to repair or regenerate the degenerated IVD. Recently, mesenchymal stem cells (MSCs) have been found to possess the capacity to differentiate into nucleus pulposus–like cells capable of synthesizing a physiological, proteoglycan-rich extracellular matrix characteristic of healthy IVDs. In this article, the authors review the use of MSCs for repopulation of the degenerating IVD. Although important obstacles to the survival and proliferation of stem cells within the degenerating disc need to be overcome, the potential for MSC therapy to slow or reverse the degenerative process remains substantial.
Novel treatment of basilar invagination resulting from an untreated C-1 fracture associated with transverse ligament avulsion
Case report and description of surgical technique
Christopher P. Ames, Frank Acosta, and Eric Nottmeier
✓ The authors describe the case of a traumatic C-1 ring fracture and transverse ligament injury in an otherwise healthy adult woman; the lesion was essentially untreated for 3 months and resulted in basilar invagination. On presentation 3 months postinjury, the patient complained of severe increasing suboccipital pain and a grinding sensation in her upper neck. Axial computerized tomography (CT) scans revealed a C-1 ring fracture, basilar invagination with the dens abutting the clivus, and significant lateral splaying of the C-1 lateral masses. Flexion—extension radiography demonstrated abnormal motion at the atlantoaxial junction. A unique surgical technique was used to address simultaneously the C1–2 instability, the displaced C-1 fracture, and basilar invagination without having to perform occipital fixation. The authors believe that an understanding of the mechanism of the cranial settling in this case (further splaying of the C-1 lateral masses and downward migration of the occipital condyles) permitted full reduction of the deformity; this was accomplished by performing a horizontal reduction of the C-1 lateral masses, using direct C-1 lateral mass screws, a rod compressor, and a cross-link. Postoperative CT scanning confirmed the success of reduction. The results in this report highlight a rare but important complication of untreated C-1 fracture and ligament disruption, and the authors describe a novel treatment technique with which to restore vertical alignment and preserve occipital C-1 motion. A variation of this technique may also be used to treat Type II transverse ligament injuries associated with C-1 ring fractures as an alternative to halo immobilization.
Darryl Lau, Vedat Deviren, and Christopher P. Ames
Posterior-based thoracolumbar 3-column osteotomy (3CO) is a formidable surgical procedure. Surgeon experience and case volume are known factors that influence surgical complication rates, but these factors have not been studied well in cases of adult spinal deformity (ASD). This study examines how surgeon experience affects perioperative complications and operative measures following thoracolumbar 3CO in ASD.
A retrospective study was performed of a consecutive cohort of thoracolumbar ASD patients who underwent 3CO performed by the senior authors from 2006 to 2018. Multivariate analysis was used to assess whether experience (years of experience and/or number of procedures) is associated with perioperative complications, operative duration, and blood loss.
A total of 362 patients underwent 66 vertebral column resections (VCRs) and 296 pedicle subtraction osteotomies (PSOs). The overall complication rate was 29.4%, and the surgical complication rate was 8.0%. The rate of postoperative neurological deficits was 6.2%. There was a trend toward lower overall complication rates with greater operative years of experience (from 44.4% to 28.0%) (p = 0.115). Years of operative experience was associated with a significantly lower rate of neurological deficits (p = 0.027); the incidence dropped from 22.2% to 4.0%. The mean operative time was 310.7 minutes overall. Both increased years of experience and higher case numbers were significantly associated with shorter operative times (p < 0.001 and p = 0.001, respectively). Only operative years of experience was independently associated with operative times (p < 0.001): 358.3 minutes from 2006 to 2008 to 275.5 minutes in 2018 (82.8 minutes shorter). Over time, there was less deviation and more consistency in operative times, despite the implementation of various interventions to promote fusion and prevent construct failure: utilization of multiple-rod constructs (standard, satellite, and nested rods), bone morphogenetic protein, vertebroplasty, and ligament augmentation. Of note, the use of tranexamic acid did not significantly lower blood loss.
Surgeon years of experience, rather than number of 3COs performed, was a significant factor in mitigating neurological complications and improving quality measures following thoracolumbar 3CO for ASD. The 3- to 5-year experience mark was when the senior surgeon overcame a learning curve and was able to minimize neurological complication rates. There was a continuous decrease in operative time as the surgeon’s experience increased; this was in concurrence with the implementation of additional preventative surgical interventions. Ongoing practice changes should be implemented and can be done safely, but it is imperative to self-assess the risks and benefits of those practice changes.
Vedat Deviren, Justin K. Scheer, and Christopher P. Ames
Sagittal imbalance of the cervicothoracic spine often causes severe pain and loss of horizontal gaze. Historically, the Smith-Peterson osteotomy has been used to restore sagittal balance. Cervicothoracic junction pedicle subtraction osteotomy (PSO) offers more controlled closure and greater biomechanical stability but has been infrequently reported in the literature. This study details the cervicothoracic PSO technique in 11 cases and correlates clinical kyphosis (chin-brow to vertical angle [CBVA]) with radiographic measurements.
Between February 2008 and September 2010, 11 patients (mean age 70 years) underwent a modified PSO (10 at C-7, 1 at T-1) for treatment of sagittal imbalance. Preoperative and postoperative sagittal plane radiographic measurements were made. The CBVA was measured on clinical photographs. Operative technique and perioperative correction were reported for all 11 patients and long-term follow-up data was reported for 9 patients, in whom the mean duration of follow-up was 23 months. Outcome measures used for these 9 patients were the Neck Disability Index, the 36-Item Short Form Health Survey (SF-36), and a visual analog scale for neck pain.
The mean values for estimated blood loss, surgical time, and hospital stay in the 11 patients were 1100 ml, 4.3 hours, and 9.9 days, respectively. The mean preoperative and immediate postoperative values (± SD) for cervical sagittal imbalance were 7.9 ± 1.4 cm and 3.4 ± 1.7 cm. The mean overall correction was 4.5 ± 1.5 cm (42.8%), the mean PSO correction 19.0°, and the mean CBVA correction 36.7°. There was essentially no correlation between preoperative C2–T1 radiographic kyphosis and preoperative CBVA (R2 = 0.0165). There was a moderate correlation with PSO correction angle and postoperative CBVA (R2 = 0.38). There was a significant decrease in both the Neck Disability Index (51.1 to 38.6, p = 0.03) and visual analog scale scores for neck pain (8.1 to 3.9, p = 0.0021). The SF-36 physical component summary scores increased by 18.4% (30.2 to 35.8) with no neurological complications.
The cervicothoracic junction PSO is a safe and effective procedure for the management of cervicothoracic kyphotic deformity. It results in excellent correction of cervical kyphosis and CBVA with a controlled closure and improvement in health-related quality-of-life measures even at early time points.
Darryl Lau, Alexander F. Haddad, Vedat Deviren, and Christopher P. Ames
Rigid multiplanar thoracolumbar adult spinal deformity (ASD) cases are challenging and many require a 3-column osteotomy (3CO), specifically asymmetrical pedicle subtraction osteotomy (APSO). The outcomes and additional risks of performing APSO for the correction of concurrent sagittal-coronal deformity have yet to be adequately studied.
The authors performed a retrospective review of all ASD patients who underwent 3CO during the period from 2006 to 2019. All cases involved either isolated sagittal deformity (patients underwent standard PSO) or concurrent sagittal-coronal deformity (coronal vertical axis [CVA] ≥ 4.0 cm; patients underwent APSO). Perioperative and 2-year follow-up outcomes were compared between patients with isolated sagittal imbalance who underwent PSO and those with concurrent sagittal-coronal imbalance who underwent APSO.
A total of 390 patients were included: 338 who underwent PSO and 52 who underwent APSO. The mean patient age was 64.6 years, and 65.1% of patients were female. APSO patients required significantly more fusions with upper instrumented vertebrae (UIV) in the upper thoracic spine (63.5% vs 43.3%, p = 0.007). Radiographically, APSO patients had greater deformity with more severe preoperative sagittal and coronal imbalance: sagittal vertical axis (SVA) 13.0 versus 10.7 cm (p = 0.042) and CVA 6.1 versus 1.2 cm (p < 0.001). In APSO cases, significant correction and normalization were achieved (SVA 13.0–3.1 cm, CVA 6.1–2.0 cm, lumbar lordosis [LL] 26.3°–49.4°, pelvic tilt [PT] 38.0°–20.4°, and scoliosis 25.0°–10.4°, p < 0.001). The overall perioperative complication rate was 34.9%. There were no significant differences between PSO and APSO patients in rates of complications (overall 33.7% vs 42.3%, p = 0.227; neurological 5.9% vs 3.9%, p = 0.547; medical 20.7% vs 25.0%, p = 0.482; and surgical 6.5% vs 11.5%, p = 0.191, respectively). However, the APSO group required significantly longer stays in the ICU (3.1 vs 2.3 days, p = 0.047) and hospital (10.8 vs 8.3 days, p = 0.002). At the 2-year follow-up, there were no significant differences in mechanical complications, including proximal junctional kyphosis (p = 0.352), pseudarthrosis (p = 0.980), rod fracture (p = 0.852), and reoperation (p = 0.600).
ASD patients with significant coronal imbalance often have severe concurrent sagittal deformity. APSO is a powerful and effective technique to achieve multiplanar correction without higher risk of morbidity and complications compared with PSO for sagittal imbalance. However, APSO is associated with slightly longer ICU and hospital stays.
Darryl Lau, Andrew K. Chan, Vedat Deverin, and Christopher P. Ames
Adult spinal deformity (ASD) develops in the setting of asymmetrical arthritic degeneration, and can also be due to iatrogenic causes, such as prior surgery. Many patients who present with ASD have undergone prior spine surgery with instrumentation. Unfortunately, contemporary studies that evaluate the effect of prior surgery or instrumentation on perioperative outcomes, readmission rates, and need for reoperation are lacking.
All ASD patients who underwent a 3-column osteotomy performed by the senior author at the authors’ institution for correction of thoracolumbar spinal deformity between 2006 and 2016 were identified. The authors compared surgical outcomes between primary (first-time) and revision cases. Further subgroup analysis was conducted to investigate the effect of the number of prior surgeries (0, 1, 2, 3, 4, and 5 or more) and the presence of spinal instrumentation on outcomes. Multivariate analysis was used to adjust for relevant and significant confounders.
A total of 300 patients were included; 38.3% of patients were male. The overall perioperative complication rate was 24.7%, and the mean length of hospitalization was 8.2 days. The 90-day readmission rate was 9.0%, and the overall follow-up reoperation rate was 26.7%. There were no significant differences in complication rates (26.6% vs 24.0%, p = 0.645), length of hospitalization (8.7 vs 7.9 days, p = 0.229), readmission rates (11.4% vs 8.1%, p = 0.387), or reoperation rates (26.6% vs 26.7%, p = 0.984) between primary and revision cases. There was no significant difference in wound complications (infections/dehiscence) requiring reoperation (5.1% vs 6.3%, p = 0.683). Subgroup analysis conducted to evaluate the effect of the number of prior spinal surgeries or the presence of spinal instrumentation did not reveal significant differences for the aforementioned surgical outcomes. In adjusted multivariate analysis, there were no significant associations between history of prior surgery (number of prior surgeries and prior instrumentation) and all of the surgical outcomes of interest.
The findings from this study suggest that patients who have undergone prior spine surgery with or without instrumentation are not at increased risk for perioperative complications, need for readmission, or reoperation following 3-column osteotomy of the thoracolumbar spine.
Darryl Lau, Joseph A. Osorio, Vedat Deviren, and Christopher P. Ames
Three-column osteotomies are increasingly being used in the elderly population to correct rigid spinal deformities. There is hesitation, however, in performing the technique in older patients because of the high risk for blood loss, longer operative times, and complications. This study assesses whether age alone is an independent risk factor for complications and length of stay.
All patients with thoracolumbar adult spinal deformity (ASD) who underwent 3-column osteotomy (vertebral column resection or pedicle subtraction osteotomy) performed by the senior author from 2006 to 2016 were identified. Demographics, clinical baseline, and surgical details were collected. Outcomes of interest included perioperative complication, ICU stay, and hospital stay. Bivariate and multivariate analyses were used to assess the association of age with outcomes of interest.
A total of 300 patients were included, and 38.3% were male. The mean age was 63.7 years: 10.3% of patients were younger than 50 years, 36.0% were 50–64 years, 45.7% were 65–79 years, and 8.0% were 80 years or older. The overall mean EBL was 1999 ml. The overall perioperative complication rate was 24.7%: 18.0% had a medical complication and 7.0% had a surgical complication. There were no perioperative or 30-day deaths. Age was associated with overall complications (p = 0.002) and medical-specific complications (p < 0.001); there were higher rates of overall and medical complications with increased age: 9.7% and 6.5%, respectively, for patients younger than 50 years; 16.7% and 10.2%, respectively, for patients 50–64 years; 31.4% and 22.6%, respectively, for patients 65–79 years; and 41.7% and 41.7%, respectively, for patients 80 years or older. However, after adjusting for relevant covariates on multivariate analysis, age was not an independent factor for perioperative complications. Surgical complication rates were similar among the 4 age groups. Longer ICU and total hospital stays were observed in older age groups, and age was an independent factor associated with longer ICU stay (p = 0.028) and total hospital stay (p = 0.003). ICU stays among the 4 age groups were 1.6, 2.3, 2.0, and 3.2 days for patients younger than 50 years, 50–64 years, 65–79 years, and 80 years or older, respectively. The total hospital stays stratified by age were 7.3, 7.7, 8.2, and 11.0 days for patients younger than 50 years, 50–64 years, 65–79 years, and 80 years or older, respectively.
Older age was associated with higher perioperative complication rates, but age alone was not an independent risk factor for complications following the 3-column osteotomy for ASD. Comorbidities and other unknown variables that come with age are likely what put these patients at higher risk for complications. Older age, however, is independently associated with longer ICU and hospital stays.
Cecilia L. Dalle Ore, Christopher P. Ames, Vedat Deviren, and Darryl Lau
Spinal deformity causing spinal imbalance is directly correlated to pain and disability. Prior studies suggest adult spinal deformity (ASD) patients with rheumatoid arthritis (RA) have more complex deformities and are at higher risk for complications. In this study the authors compared outcomes of ASD patients with RA following thoracolumbar 3-column osteotomies to outcomes of a matched control cohort.
All patients with RA who underwent 3-column osteotomy for thoracolumbar deformity correction performed by the senior author from 2006 to 2016 were identified retrospectively. A cohort of patients without RA who underwent 3-column osteotomies for deformity correction was matched based on multiple clinical factors. Data regarding demographics and surgical approach, along with endpoints including perioperative outcomes, reoperations, and incidence of proximal junctional kyphosis (PJK) were reviewed. Univariate analyses were used to compare patients with RA to matched controls.
Eighteen ASD patients with RA were identified, and a matched cohort of 217 patients was generated. With regard to patients with RA, 11.1% were male and the mean age was 68.1 years. Vertebral column resection (VCR) was performed in 22.2% and pedicle subtraction osteotomy (PSO) in 77.8% of patients. Mean case length was 324.4 minutes and estimated blood loss (EBL) was 2053.6 ml. Complications were observed in 38.9% of patients with RA and 29.0% of patients without RA (p = 0.380), with a trend toward increased medical complications (38.9% vs 21.2%, p = 0.084). Patients with RA had a significantly higher incidence of deep vein thrombosis (DVT)/pulmonary embolism (PE) (11.1% vs 1.8%, p = 0.017) and wound infections (16.7% vs 5.1%, p = 0.046). PJK occurred in 16.7% of patients with RA, and 33.3% of RA patients underwent reoperation. Incidence rates of PJK and reoperation in matched controls were 12.9% and 25.3%, respectively (p = 0.373, p = 0.458). At follow-up, mean sagittal vertical axis (SVA) was 6.1 cm in patients with RA and 4.5 cm in matched controls (p = 0.206).
Findings from this study suggest that RA patients experience a higher incidence of medical complications, specifically DVT/PE. Preoperative lower-extremity ultrasounds, inferior vena cava (IVC) filter placement, and/or early initiation of DVT prophylaxis in RA patients may be indicated. Perioperative complications, morbidity, and long-term outcomes are otherwise similar to non-RA patients.