Rhombencephalosynapsis (RES) is a rare congenital malformation of the cerebellum characterized by hypogenesis or agenesis of the vermis and fusion of the cerebellar hemispheres with or without fusion of the dentate nuclei and superior cerebellar peduncles. No genetic or chromosomal abnormalities have been identified for RES. Although the occurrence of RES is presumed to be sporadic, no clear pattern of inheritance has been identified. The authors report on a 17-year-old girl with autosomal dominant polycystic kidney disease Type 1 as well as RES.
Robert Elliott and David H. Harter
Natalie Zusman, Jacqueline L. Munch, Alexander Ching, Robert Hart and Jung Yoo
A lack of information exists on the relationship between preoperative epidural spinal injections and outcomes after spine surgery. There is concern that injections might cause local changes, increasing the infection risk and surgical difficulty. Therefore, the authors explored the relationship between preoperative spinal injections and postoperative outcome.
The cohort was comprised of patients who underwent thoracic and/or lumbar arthrodesis during the years 2007–2010 and had complete (preoperatively and 3 months postoperatively) outcome scores. Patients’ clinical courses were reviewed to determine the occurrence of major complications within a 30-day postoperative period. Patient-perceived outcomes were evaluated using the Oswestry Disability Index (ODI) and the SF-12 (12-Item Short Form Health Survey): mental component summary (MCS) and physical component summary (PCS) scores. Analyses were based on exposure to injections and were performed using chi-square exact tests and paired and unpaired t-tests.
Two hundred eighty patients met the inclusion criteria: 117 patients (41.8%) received and 163 patients (58.2%) did not receive preoperative epidural spinal injections. Overall, the likelihood of complication did not differ with respect to exposure (13.7% injection vs 11.7% noninjection); however, injected patients observed a 7.4-fold risk of developing surgical wound complications over noninjected patients (5.1% vs 0.6%, p = 0.02).
Patient-perceived outcomes measures demonstrated no differences between groups. Three months postoperatively, the MCS and ODI scores were similar (MCS: 49.6 ± 11.6 injection vs 47.4 ± 12.8 noninjection; ODI: 35.8 ± 18.0 vs 34.4 ± 19.1). MCS or ODI score improvement (preoperatively compared with 3 months postoperatively) did not vary between groups. Injected patients maintained a 2-point lower PCS score at entry and 3 months postoperatively as compared with noninjected peers (entry: 27.6 ± 8.2 injection vs 29.5 ± 9.3 noninjection, p = 0.09; 3 months: 33.3 ± 8.6 vs 35.7 ± 9.0, p = 0.03); the PCS score improvements between injected and noninjected groups were similar (5.7 ± 9.9 vs 6.2 ± 9.7).
Patients exposed to preoperative epidural injections had similar complication rates to those who never received a spinal injection. However, they had a greater risk of developing wound complications. These complications had no effect on short-term improvements in outcome measures.
Vishwajeet Singh, Tarush Rustagi and Robert Hart
The sacrum forms the distal end of the spine and communicates with the pelvis. Fractures involving the sacrum are complex and may disrupt this vital communication. Neglecting these fractures may result in malunion, which often causes significant alteration in the pelvic parameters and sagittal balance. Management of ensuing deformities is complex and poorly described. The authors present a case of sacral malunion with sagittal imbalance treated with a low lumbar osteotomy.
Michael L. Levy, Robert C. Granville, David Hart and Hal Meltzer
Object. The objective of this retrospective review was to identify patients on the pediatric neurosurgical ward with deep venous thrombosis (DVT) to develop diagnostic and treatment-related guidelines.
Methods. The authors performed a retrospective chart review of all cases of DVT presenting to the Children's Hospital between March 1986 and February 1997. Of 32 patients identified, 14 were followed by the neurosurgical service. Current records were additionally evaluated to assess follow-up condition in the patients as well as outcome. Variables included diagnosis, race, age, follow-up duration, outcome, presenting signs/symptoms, involved vessel(s), concurrent disease, diagnostic modalities, and treatment.
Patient age ranged from 1 to 16 years (mean 12.6 years, median 15 years). There were five girls and nine boys. Eight DVTs were right sided and six were left sided. Presenting symptoms included swelling of the affected extremity in 11 patients, pain in five, erythema in one, and cardiopulmonary arrest in two. Comorbidities included previous orthopedic procedures in three, brain tumors in two, and sepsis, fracture, pulmonary disease, preexisting coagulation disorders, and brain abscess in one patient each. Eight patients presented with a history of trauma. Two patients had undergone chemotherapy. Diagnostic studies included ultrasonography and venography in one, venography alone in two, computerized tomography (CT) scanning and venography in one, tagged red blood cell studies in one, ultrasonography and CT scanning in one, and ultrasonography alone in eight. In one patient an inferior vena cava filter was placed and one patient was treated with oral warfarin alone. One patient with a brain tumor died while hospitalized. In four patients there was evidence of rheumatological disease in the group of patients not treated neurosurgically. Two patients suffered recurrences during the follow-up period (mean 20 months)In the entire series of 32 patients there were five total deaths. Of these, two patients experienced six recurrences each, and one other patient suffered four recurrences. Of note, none of the recurrences was observed in patients with underlying coagulation disorders.
Conclusions. Children with DVT can experience serious complications in the form of both morbidity and mortality. Although most thrombotic complications have been found in patients with femoral lines, prolonged treatment involving a central line has been found to be a significant predictor of DVT. Multiple treatment modalities currently exist for children with DVT. Low-molecular weight heparin therapy has many benefits over unfractionated heparin agents and may be more appropriate for the prophylaxis or treatment of children and adolescents with DVT because of its acceptable safety and efficacy. Clinical data for neonates and young children remain incomplete.
Robert Elliott, Stephen Kalhorn, Donato Pacione, Howard Weiner, Jeffrey Wisoff and David Harter
Patients with symptomatic Chiari malformation Type I (CM-I) typically exhibit a chronic, slowly progressive disease course with evolution of symptoms. However, some authors have reported acute neurological deterioration in the setting of CM-I and acquired Chiari malformations. Although brainstem dysfunction has been documented in patients with CM-II and hydrocephalus or shunt malfunction, to the authors' knowledge only 1 report describing ventriculoperitoneal (VP) shunt malfunction causing neurological deterioration in a patient with CM-I exists.
The authors report on their experience with the treatment of previously asymptomatic CM-I in 2 children who experienced quite different manifestations of acute neurological deterioration secondary to VP shunt malfunction. Presumably, VP shunt malfunction created a positive rostral pressure gradient across a stenotic foramen magnum, resulting in tetraparesis from foramen magnum syndrome in 1 patient and acute ataxia and cranial nerve deficits from syringobulbia in the other. Although urgent shunt revisions yielded partial recovery of neurological function in both patients, marked improvement occurred only after posterior fossa decompression.
Alan H. Daniels, Satoshi Kawaguchi, Alec G. Contag, Farbod Rastegar, Garrett Waagmeester, Paul A. Anderson, Melanie Arthur and Robert A. Hart
Beginning in 2008, the Centers for Medicare and Medicaid Service (CMS) determined that certain hospital-acquired adverse events such as surgical site infection (SSI) following spine surgery should never occur. The following year, they expanded the ruling to include deep vein thrombosis (DVT) and pulmonary embolism (PE) following total joint arthroplasty. Due to their ruling that “never events” are not the payers' responsibility, CMS insists that the costs of managing these complications be borne by hospitals and health care providers, rather than billings to health care payers for additional care required in their management. Data comparing the expected costs of such adverse events in patients undergoing spine and orthopedic surgery have not previously been reported.
The California State Inpatient Database (CA-SID) from 2008 to 2009 was used for the analysis. All patients with primary procedure codes indicating anterior cervical discectomy and fusion (ACDF), posterior lumbar interbody fusion (PLIF), lumbar laminectomy (LL), total knee replacement (TKR), and total hip replacement (THR) were analyzed. Patients with diagnostic and/or treatment codes for DVT, PE, and SSI were separated from patients without these complication codes. Patients with more than 1 primary procedure code or more than 1 complication code were excluded. Median charges for treatment from primary surgery through 3 months postoperatively were calculated.
The incidence of the examined adverse events was lowest for ACDF (0.6% DVT, 0.1% PE, and 0.03% SSI) and highest for TKA (1.3% DVT, 0.3% PE, 0.6% SSI). Median inpatient charges for uncomplicated LL was $51,817, compared with $73,432 for ACDF, $143,601 for PLIF, $74,459 for THR, and $70,116 for TKR. Charges for patients with DVT ranged from $108,387 for TKR (1.5 times greater than index) to $313,536 for ACDF (4.3 times greater than index). Charges for patients with PE ranged from $127,958 for TKR (1.8 times greater than index) to $246,637 for PLIF (1.7 times greater than index). Charges for patients with SSI ranged from $168,964 for TKR (2.4 times greater than index) to $385,753 for PLIF (2.7 times greater than index).
Although incidence rates are low, adverse events of spinal procedures substantially increase the cost of care. Charges for patients experiencing DVT, PE, and SSI increased in this study by factors ranging from 1.8 to 4.3 times those for patients without such complications across 5 common spinal and orthopedic procedures. Cost projections by health care providers will need to incorporate expected costs of added care for patients experiencing such complications, assuming that the cost burden of such events continues to shift from payers to providers.
Ahmed S. Mohamed, Jung Yoo, Robert Hart, Brian T. Ragel, Jayme Hiratzka, D. Kojo Hamilton, Penelope D. Barnes and Alexander C. Ching
The authors evaluated the efficacy of posterior instrumentation for the management of spontaneous spinal infections. Standard surgical management of spontaneous spinal infection is based on debridement of the infected tissue. However, this can be very challenging as most of these patients are medically debilitated and the surgical debridement requires a more aggressive approach to the spine either anteriorly or via an expanded posterior approach. The authors present their results using an alternative treatment method of posterior-only neuro-decompression and stabilization without formal debridement of anterior tissue for treating spontaneous spinal infection.
Fifteen consecutive patients were treated surgically by 2 of the authors. All patients had osteomyelitis and discitis and were treated postoperatively with intravenous antibiotics for at least 6 weeks. The indications for surgery were failed medical management, progressive deformity with ongoing persistent spinal infection, or neurological deficit. Patients with simple epidural abscess without bony instability were treated with laminectomy and were not included in this series. Fourteen patients were treated with posterior-only decompression and long-segment rigid fixation, without formal debridement of the infected area. One patient was treated with staged anterior and posterior surgery due to delay in treatment related to medical comorbidities. The authors examined as their outcome the ambulatory status and recurrence of deep infection requiring additional surgery or medical treatment.
Of the initial 15 patients, 10 (66%) had a minimum 2-year follow-up and 14 patients had at least 1 year of followup. There were no recurrent spinal infections. There were 3 unplanned reoperations (1 for loss of fixation, 1 for early superficial wound infection, and 1 for epidural hematoma). Nine (60%) of 15 patients were nonambulatory at presentation. At final followup, 8 of 15 patients were independently ambulatory, 6 required an assistive device, and 1 remained nonambulatory.
Long-segment fixation, without formal debridement, resulted in resolution of spinal infection in all cases and in significant neurological recovery in almost all cases. This surgical technique, when combined with aggressive antibiotic therapy and a multidisciplinary team approach, is an effective way of managing serious spinal infections in a challenging patient population.
Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy
Presented at the 2012 Joint Spine Section Meeting
Justin S. Smith, Christopher I. Shaffrey, Virginie Lafage, Benjamin Blondel, Frank Schwab, Richard Hostin, Robert Hart, Brian O'Shaughnessy, Shay Bess, Serena S. Hu, Vedat Deviren, Christopher P. Ames and International Spine Study Group
Sagittal spinopelvic malalignment is a significant cause of pain and disability in patients with adult spinal deformity. Surgical correction of spinopelvic malalignment can result in compensatory changes in spinal alignment outside of the fused spinal segments. These compensatory changes, termed reciprocal changes, have been defined for thoracic and lumbar regions but not for the cervical spine. The object of this study was to evaluate postoperative reciprocal changes within the cervical spine following lumbar pedicle subtraction osteotomy (PSO).
This was a multicenter retrospective radiographic analysis of patients from International Spine Study Group centers. Inclusion criteria were as follows: adults (>18 years old) with spinal deformity treated using lumbar PSO, a preoperative C7–S1 plumb line greater than 5 cm, and availability of pre- and postoperative full-length standing radiographs.
Seventy-five patients (60 women, mean age 59 years) were included. The lumbar PSO significantly improved sagittal alignment, including the C7–S1 plumb line, C7–T12 inclination, and pelvic tilt (p <0.001). After lumbar PSO, reciprocal changes were seen to occur in C2–7 cervical lordosis (from 30.8° to 21.6°, p <0.001), C2–7 plumb line (from 27.0 mm to 22.9 mm), and T-1 slope (from −38.9° to −30.4°, p <0.001). Ideal correction of sagittal malalignment (postoperative sagittal vertical alignment < 50 mm) was associated with the greatest relaxation of cervical hyperlordosis (−12.4° vs −5.7°, p = 0.037). A change in cervical lordosis correlated with changes in T-1 slope (r = −0.621, p <0.001), C7–T12 inclination (r = 0.418, p <0.001), T12–S1 angle (r = −0.339, p = 0.005), and C7–S1 plumb line (r = 0.289, p = 0.018). Radiographic parameters that correlated with changes in cervical lordosis on multivariate linear regression analysis included change in T-1 slope and change in C2–7 plumb line (r2 = 0.53, p <0.001).
Adults with positive sagittal spinopelvic malalignment compensate with abnormally increased cervical lordosis in an effort to maintain horizontal gaze. Surgical correction of sagittal malalignment results in improvement of the abnormal cervical hyperlordosis through reciprocal changes.
Robert A. Hart, Christopher M. Domes, Brady Goodwin, Charles R. D'Amato, Jung U. Yoo, Ronald J. Turker and Matthew F. Halsey
The ideal surgical management of high-grade spondylolisthesis remains unclear. Concerns regarding the original Bohlman transsacral interbody fusion technique with stand-alone autologous fibular strut include late graft fracture and incomplete reduction of lumbosacral kyphosis. The authors' goal was to evaluate the radiographic and surgical outcomes of patients treated for high-grade spondylolisthesis with either transsacral S-1 screws or standard pedicle screw fixation augmenting the Bohlman posterior transsacral interbody fusion technique.
A retrospective review of patients who underwent fusion for high-grade spondylolisthesis in which a Bohlman oblique posterior interbody fusion augmented with either transsacral or standard pedicle screw fixation was performed by 4 spine surgeons was completed. Estimated blood loss, operating time, perioperative complications, and need for revision surgery were evaluated. Upright pre- and postsurgical lumbar spine radiographs were compared for slip percent and slip angle.
Sixteen patients (12 female and 4 male) with an average age of 29 years (range 9–66 years) were evaluated. The average clinical follow-up was 78 months (range 5–137 months) and the average radiographic follow-up was 48 months (range 5–108 months). Ten L4–S1 and 6 L5–S1 fusions were performed. Five fibular struts and 11 titanium mesh cages were used for interbody fusion. Six patients had isolated transsacral screws placed, with 2 (33%) of the 6 requiring revision surgery for nonunion. No nonunions were observed in patients undergoing spanning pedicle screw fixation augmenting the interbody graft. Six patients experienced perioperative complications including 3 iliac crest site infections, 1 L-5 radiculopathy without motor involvement, 1 deep vein thrombosis, and 1 epidural hematoma requiring irrigation and debridement. The average estimated blood loss and operating times were 763 ml and 360 minutes, respectively. Slip percent improved from an average of 62% to 37% (n = 16; p < 0.01) and slip angle improved from an average of 18° to 8° (n = 16; p < 0.01). No patient experienced L-5 or other motor deficit postoperatively.
The modified Bohlman technique for treatment of high-grade spondylolisthesis has reproducible outcomes among multiple surgeons and results in significant improvements in slip percent and slip angle. Fusion rates were high (14 of 16; 88%), especially with spanning instrumentation augmenting the oblique interbody fusion. Rates of L-5 motor deficit were low in comparison with techniques involving reduction of the anterolisthesis.
Virginie Lafage, Neil J. Bharucha, Frank Schwab, Robert A. Hart, Douglas Burton, Oheneba Boachie-Adjei, Justin S. Smith, Richard Hostin, Christopher Shaffrey, Munish Gupta, Behrooz A. Akbarnia and Shay Bess
Sagittal spinopelvic imbalance is a major contributor to pain and disability for patients with adult spinal deformity (ASD). Preoperative planning is essential for pedicle subtraction osteotomy (PSO) candidates; however, current methods are often inaccurate because no formula to date predicts both postoperative sagittal balance and pelvic alignment. The authors of this study aimed to evaluate the accuracy of 2 novel formulas in predicting postoperative spinopelvic alignment after PSO.
This study is a multicenter retrospective consecutive PSO case series. Adults with spinal deformity (> 21 years old) who were treated with a single-level lumbar PSO for sagittal imbalance were evaluated. All patients underwent preoperative and a minimum of 6-month postoperative radiography. Two novel formulas were used to predict the postoperative spinopelvic alignment. The results predicted by the formulas were then compared with the actual postoperative radiographic values, and the formulas' ability to identify successful (sagittal vertical axis [SVA] ≤ 50 mm and pelvic tilt [PT] ≤ 25°) and unsuccessful (SVA > 50 mm or PT > 25°) outcomes was evaluated.
Ninety-nine patients met inclusion criteria. The median absolute error between the predicted and actual PT was 4.1° (interquartile range 2.0°–6.4°). The median absolute error between the predicted and actual SVA was 27 mm (interquartile range 11–47 mm). Forty-one of 54 patients with a formula that predicted a successful outcome had a successful outcome as shown by radiography (positive predictive value = 0.76). Forty-four of 45 patients with a formula that predicted an unsuccessful outcome had an unsuccessful outcome as shown by radiography (negative predictive value = 0.98).
The spinopelvic alignment formulas were accurate when predicting unsuccessful outcomes but less reliable when predicting successful outcomes. The preoperative surgical plan should be altered if an unsuccessful result is predicted. However, even after obtaining a predicted successful outcome, surgeons should ensure that the predicted values are not too close to unsuccessful values and should identify other variables that may affect alignment. In the near future, it is anticipated that the use of these formulas will lead to better surgical planning and improved outcomes for patients with complex ASD.