Matthew J. Geck

The Ponte procedure: posterior only treatment of Scheuermann's kyphosis using segmental posterior shortening and pedicle screw instrumentation.

Study Design Case series. Objective To examine a consecutive series of surgically treated Scheuermann kyphosis that had a posterior only procedure with segmental pedicle screw fixation and segmental Ponte osteotomies. Summary of Background Data The gold standard for surgical treatment of Scheuermann kyphosis (a rigid kyphosis associated with wedged vertebral bodies occurring in late childhood or adolescence) has been combined anterior and posterior approach surgery. Alberto Ponte has advocated a posterior-only procedure with posterior column shortening via segmental osteotomies, but his procedure has not been widely accepted owing to concerns that without anterior column support there would be a risk of correction loss and/or instrumentation failure. With the advent of improved spinal instrumentation and fixation with thoracic pedicle screws, the Ponte procedure may offer an advantage over anterior/posterior reconstruction. Methods The study prospectively enrolled 17 consecutive patients with Scheuermann kyphosis who were treated with the Ponte procedure by the senior surgeon at one institution. Standardized radiographic analysis was performed and included full-length coronal and sagittal radiographs preoperatively, postoperatively, and at final follow-up. Analysis also included the correction obtained through the most severe, wedged segments of the deformity by the osteotomies. Results Seventeen patients had the Ponte procedure satisfactorily performed. No patient needed an anterior approach to achieve sufficient correction or fusion. There were no reoperations for nonunion or instrumentation failure. Correction of the instrumented levels was 61% and of worst Cobb was mean 49%. The apex of the deformity was measured over the most deformed 3 to 7 wedged segments. The average correction across the apex was 9.3 degrees per osteotomy (range 5.9 to 15). No patient lost more than 4 degrees of correction through their instrumented and fused levels. There were no neurologic complications. There was one late infection with a solid fusion treated with instrumentation removal and intravenous antibiotics. Conclusions Using thoracic pedicle screw instrumentation as the primary anchor, the Ponte procedure was successfully performed in 17 consecutive patients for Scheuermann kyphosis with no exclusions for the size or rigidity of the kyphosis. Results were as good as anterior/posterior historical controls with excellent correction and minimal loss of correction at final follow-up. This procedure avoids the morbidity and extended operative time attributed to the anterior approach. Level of Evidence Therapeutic study, level IV [case series (no, or historical, control group)].

The posterior approach for lumbar and thoracolumbar adolescent idiopathic scoliosis: posterior shortening and pedicle screws.

Study Design. Prospective clinical case series. Background Data. Lumbar and thoracolumbar adolescent idiopathic scoliosis has traditionally been treated with an anterior approach and instrumentation. This anterior method often has had problems with kyphosis, pseudarthrosis, and loss of correction. The senior author has had good results treating these same lumbar and thoracolumbar curves posteriorly with wide posterior release and segmental instrumentation. In this series of his evolving technique, he adds pedicle screws as the sole anchor in the thoracolumbar/lumbar curves. Objectives. To prospectively evaluate outcomes, coronal and sagittal radiographic results, balance parameters, complications, and reoperations in a group of consecutive patients with lumbar and thoracolumbar adolescent idiopathic scoliosis. These patients were surgically treated with wide posterior release and segmental posterior screw instrumentation with 2-year minimum follow-up (range 26–47 months). Methods. Sixty-two consecutive patients with thoracolumbar and lumbar adolescent idiopathic scoliosis were treated with a wide posterior release and segmental pedicle screw instrumentation limited to the curve defined by the Cobb measurement. The patients were evaluated clinically and radiographically at intervals up to 36 months. There was 2-year minimum follow-up. Results. One patient was lost to follow-up. Of the remaining 61 patients, there were 51 Lenke 5 Type curves, 7 Lenke Type 3C curves, and 3 Lenke Type 6 curves. Only the curve defined by the Cobb measurement was fused. A total of 613 pedicle screws were placed safely. Average coronal correction of the thoracolumbar/lumbar curves was from 52° to 10° (80%). In the sagittal plane, lumbar lordosis was normalized from 41° with a wide range (20°–70°) to 42° with a normal range (34°–47°). There were no pseudoarthroses, no reoperations, no infections, no problems with screw placement, and excellent maintenance of correction at last follow-up. The lowest instrumented vertebrae had 81% correction of coronal angulation, center sacral line to lowest instrumented vertebrae was improved from 2.4 cm to 0.7 cm, and apex to center sacral line was improved from 5.2 cm to 1.5 cm. The C7 plumb line to center sacral line was also improved from 2.5 cm to 0.6 cm, illustrating the centering of the trunk. Conclusions. Wide posterior release and segmental pedicle screw instrumentation has excellent radiographic and clinical results with minimal complications. There were no pseudoarthroses and no reoperations.

High-grade isthmic dysplastic spondylolisthesis: monosegmental surgical treatment.

Study Design. A prospective single arm cohort. Objective. To study the results of distraction reduction of high-grade isthmic dysplastic spondylolisthesis with posterior lumbar interbody fusion and posterior compression in a consecutive, prospectively collected series of adolescent patients. Summary of Background Data. High-grade isthmic dysplastic spondylolisthesis has been associated with a high complication and failure rate regardless of the method of surgical treatment, including in situ fusion, cast correction and fusion, anterior fusion, posterior instrumented fusion, and combination procedures. Methods. A total of 18 adolescents with the diagnosis and a minimum 50% slip underwent the procedure of Gill decompression, temporary distraction with reduction of the deformity, complete lumbosacral discectomy, posterior lumbar interbody fusion with Harm’s cage and autogenous iliac graft, and posterior monosegmental compression instrumentation with pedicular fixation. Results. Follow-up ranged from 2.3 to 5 years. Slip improved from 77% to 13% and slip angle from 35° to 3.8° initially and 4.3° at final follow-up. One patient had loss of 16° of slip angle but achieved arthrodesis. Sacral inclination improved from 28° to 39°. There were no neurologic or infectious complications. There were no overt instrumentation failures. Arthrodesis was achieved in every instance. Two patients had structural complications, neither of which underwent reoperation. Conclusions. The index procedure provided near-anatomic correction of high-grade spondylolisthesis, which is maintained at a minimum 2-year follow-up without significant complications. There were two structural complications. Anterior column structural support and posterior compressive instrumentation help restore the necessary biomechanics to allow clinical fusion and success. This series has led the senior author to evolve his technique tooften include caudad fixation to the pelvis and/or cephalad fixation to L4.

Comparison of surgical treatment in Lenke 5C adolescent idiopathic scoliosis: anterior dual rod versus posterior pedicle fixation surgery: a comparison of two practices.

Study Design. Multicenter analysis of 2 groups of patients surgically treated for Lenke 5C adolescent idiopathic scoliosis (AIS). Objective. Compare patients with Lenke 5C scoliosis surgically treated with anterior spinal fusion with dual rod instrumentation and anterior column support with patients surgically treated with posterior release and pedicle screw instrumentation. Summary of Background Data. Treatment of single, structural, lumbar, and thoracolumbar curves in patients with AIS has been the subject of some debate. Advocates of the anterior approach assert that their technique spares posterior musculature and may save distal fusion levels, and that with dual rods and anterior column support the issues with nonunion and kyphosis have been obviated. Advocates of the posterior approach assert that with the change to posterior pedicle screw based instrumentation that correction and levels are equivalent, and the posterior approach avoids the issues with nonunion and kyphosis. This report directly compares the results of posterior versus anterior instrumented fusions in the operative treatment of adolescent idiopathic Lenke 5C curves. Methods. We analyzed 62 patients with Lenke 5C based on radiographic and clinical data at 2 institutions: 31 patients treated with posterior, pedicle-screw instrumented fusions at 1 institution (group PSF); and 31 patients with anterior, dual-rod instrumented fusions at another institution (group ASF). Multiple clinical and radiographic parameters were evaluated and compared. Results. The mean age, preoperative major curve magnitude, and preoperative lowest instrumented vertebral (LIV) tilt were similar in both groups (age: PSF = 15.5 years, ASF = 15.6 years; curve size: PSF = 50.3° ± 7.0°, ASF = 49.0° ± 6.6°; LIV tilt: PSF = 27.5° ± 6.5°, ASF = 27.8° ± 6.2°). After surgery, the major curve corrected to an average of 6.3° ± 3.2° (87.6% ± 5.8%) in the PSF group, compared with 12.1° ± 7.4° (75.7% ± 14.8%) in the ASF group (P < 0.01). At final follow-up, the major curve measured 8.0° ± 3.0° (84.2% ± 5.8% correction) in the PSF group, compared with 15.9° ± 9.0° (66.6% ± 17.9%) in the ASF group (P = 0.01). This represented a loss of correction of 1.7° ± 1.9° (3.4% ± 3.7%) in the PSF group, and 3.8° ± 4.2° (9.4% ± 10.7%) in the ASF group (P = 0.028). The LIV tilt decreased to 4.1° ± 3.4° after surgery in the PSF group, and 4.5° ± 3.7° in the ASF group. At final follow-up, the LIV tilt was 5.1° ± 3.5° in the PSF group, and 4.5° ± 3.7° in the ASF group. EBL was identical in both groups, and length of hospital stay was significantly (P < 0.01) shorter in the PSF group (4.8 vs. 6.1 days). There were no complications in either group which extended hospital stay or required an unplanned second surgery. Conclusion. At a minimum of 2-year follow-up, adolescents with Lenke 5C curves demonstrated statistically significantly better curve correction, less loss of correction over time, and shorter hospital stays when treated with a posterior release with pedicle screw instrumented fusion compared with an anterior instrumented fusion with dual rods for similar patient populations.

Epidural Hematoma and Intraoperative Hemorrhage in a Spine Trauma Patient on Pradaxa (dabigatran)

Study Design. The authors present a case report of a 72-year-old man who presented with back pain and lower extremity weakness after a fall from his roof. Objective. Use of dabigatran (Pradaxa), a new oral anticoagulant, is rapidly increasing. Spine specialists should aware of this medications place for the management of patients with spine pathology. In particular, we intend to report on the emergent treatment of a patient with spinal trauma and epidural hematoma with cord compression. Summary of Background Data. Dabigatran (Pradaxa) is approved by the Food and Drug Administration to decrease stroke risk in patients with atrial fibrillation. Unlike warfarin, dabigatran does not require international normalized ratio monitoring. On the contrary, it is difficult to reverse in patients requiring emergent surgical intervention. Methods. This is a retrospective review of a patient treated at our institution. Results. The patient presented with burst fractures at the T7 and T12 levels. Cord compression was noted at both levels, and was worse at T12. Canal stenosis resulted from both retropulsed bone and epidural hematoma. The patient exhibited bilateral lower extremity numbness and weakness, ASIA C. The patient was taken urgently to the operating room for cord decompression and planned operative stabilization. The treating team used a number of recommended “reversal” agents with little effect on the severe intraoperative hemorrhage. Failure to control the bleeding required interruption of the procedure after the canal decompression. The patient was taken back to the operating room 7 days later for an instrumented posterior spinal fusion. Conclusion. As dabigatran (Pradaxa) has recently been approved by the Food and Drug Administration, many spine specialists are not familiar with this agent. Many of the reversal agents (e.g., vitamin K and protamine), useful for other classes of anticoagulants, have no impact on Pradaxa. Similarly, prothrombin time and partial thromboplastin times have limited utility in estimating the patients true clotting status. The purpose of this case report is to alert spine specialists to this drug and its implications on spine care. The drugs pharmacokinetics, clinical assessment of clotting status, and reversal options are discussed.

An outcomes analysis of the treatment of cervical pseudarthrosis with posterior fusion.

Study Design. A retrospective review of 33 consecutive patients treated with posterior fusion and selective nerve root decompression for the treatment of pseudarthrosis following anterior cervical discectomy and fusion. Objectives. Use standardized outcome measures to evaluate the results of posterior fusion with selective nerve root decompression as a treatment option for symptomatic pseudarthrosis of the cervical spine. Summary of Background Data. Pseudarthrosis after anterior cervical discectomy and fusion has been recognized as a cause of continued cervical pain and unsatisfactory outcomes. Debate continues as to whether a revision anterior approach or a posterior fusion procedure is the best treatment for symptomatic cervical pseudarthrosis. To our knowledge, standardized outcome measures have not been used to evaluate the results of either surgical treatment option; therefore, it is difficult to evaluate outcomes in these patients, let alone compare surgical treatment options. Data on fusion rates in these two surgical treatment groups suggest a trend of a higher fusion rate with utilization of a posterior revision procedure, but the largest study to date includes the study of only 19 patients treated with a posterior fusion. Methods. Thirty-three consecutive patients with symptomatic pseudarthrosis following anterior cervical discectomy and fusion were treated with selective nerve root decompression and posterior fusion using iliac crest or local bone graft as well as posterior wiring and/or lateral mass plating. The average follow-up period was 46 months (range, 20–86 months). Patients were assessed using physical examination, flexion-extension lateral radiographs, and standardized outcome measures including the SF-36, Arthritis Impact Measurement Scales 2, and Cervical Spine Outcomes Questionnaire. Results. All 33 patients (100%) demonstrated a solid fusion at their most recent follow-up, and all 33 patients noted significant improvement in their preoperative symptoms. No difference in fusion status was noted between those treated with iliac crest versus patients treated with local bone graft—all had a solid fusion; 72% of the patients were satisfied with the result of their surgery. Cervical Spine Outcomes Questionnaire pain scales demonstrated 52% of patients reported mild or nopain at follow-up, whereas 20% described their pain as “discomforting” and 28% of the patients continued to report moderate to severe pain. Conclusions. This is the first study to our knowledge to use standardized outcome measures to assess clinical outcome in patients treated with posterior fusion for pseudarthrosis after anterior cervical discectomy and fusion. Patients and surgeons need to understand the potential for success with this revision procedure but also be aware of the relatively high rate of continued moderate to severe pain observed in this patient population even after a solid fusion is achieved. All of the patients in this study fused with a single posterior fusion procedure, further supporting the relatively higher fusion rates observed in the literature using posterior fusion as a treatment for cervical pseudarthrosis. Our results also support the ability of surgeons to use local bone graft without iliac crest in a posterior fusion for cervical pseudarthrosis and therefore avoid the morbidity associated with iliac crest bone graft harvest.

Assessment of cervical ligamentous injury in trauma patients using MRI

During a 7-year period, a consecutive retrospective series of 89 trauma patients at a Level One trauma center who had negative standard radiographs with suspected occult cervical injury were administered a cervical magnetic resonance imaging (MRI) scan. The MRI studies were fully able to assess the ligamentous status of the cervical spine in all patients and were the final step in determining the treatment of the spine. Of the total 89 patients, 82 had no ligamentous injury, and 7 had ligamentous injury. Two patients underwent surgery because of the findings on the MRI study. MRI studies of patients with negative standard radiographs but with suspected occult cervical injury are excellent and safe studies for the evaluation of cervical spinal stability because of their ability to detect ligamentous injuries that are not evident on plain radiographs.

Feasibility of rigid upper cervical instrumentation in children: tomographic analysis of children aged 2-6.

Study Design: Tomographic analysis of occipitocervical (OC) instability in children aged between 2 and 6 years. Objective: To assess the feasibility of screw placement in various bone anchors in the OC region in young children. Summary of Background Data: The use of rigid stabilization in the pediatric patients is gradually increasing. No study has comprehensively assessed the suitability of bony anatomy of the OC region for screw placement, especially in younger children. Methods: A total of 50 patients (2–6 y, 10 each) who underwent skull and cervical CT scanning were randomly queried using an x-ray database. Screw placement was considered feasible if there was at least 0.5 mm of bone around a 3.5 mm screw through its trajectory. When the bony channel measured 3.5–4.0 mm, placement was considered possible, but difficult. Results: Statistically, most measures were similar from the right to left sides. External occipital protuberance thickness increased from a mean value of 8.60 mm to a mean value of 10.73 mm. The mean C1 lateral mass length and width varied from 15.26 to 16.67 mm (P=0.056) and 7.34 to 8.58 mm (P=0.0005), respectively, with age. The mean C2 pedicle width and length varied from 3.85 to 4.18 and 17.11 to 19.8 mm, respectively, with age. The mean C2 laminar screw length increased from 20.4 to 22.66 mm with age (P<0.001). C2 lamina widths did not vary much by age. The mean C1–C2 transarticular path length and height increased from 26.7 to 33.6 mm and 2.58 to 3.09 mm, respectively, with age. The width was less directly variable by age (2.68–3.09 mm). Conclusions: Standard 3.5 mm screws can be used for OC and upper cervical instabilities in children aged between 2 and 6 years. Some anchor points appeared safer compared with others. The occipital keel, C1 lateral mass, and C2 laminae offered adequate space for screw placement in almost all cases. C2 pedicles offered adequate space in 49 sides and barely adequate space in 25 pedicles. Transarticular screws could be safely placed in only 4 of 100 sides. Close radiographic assessment of the vertebral artery course and bony architecture are recommended before surgery in pediatric patients with OC and upper cervical instability.

Posterior cervical laminoplasty in the North American Population: A minimum of two year follow-up.

BACKGROUND The efficacy of expansile cervical laminoplasty for cervical spondylotic myelopathy has been validated in the literature. To date, however, the majority of large, long-term data in the literature have originated in Japan. Few studies have originated from North America that include follow up greater than one year, and none of these includes a single surgeons experience. This paper presents the retrospective results of a single surgeon with an average follow up of 47 months in a large population of North American patients. METHODS A single surgeons series of 80 consecutive patients who underwent expansile open-door laminoplasty for cervical myelopathy was reviewed. The severity of disability was graded using the Nurick Functional Disability Score and the Miami Upper Extremity Function (MUEF) score. Patients were evaluated preoperatively, six months postoperatively, and at a minimum of 24 months postoperatively. All examinations were performed by a single physician. MRI scans of the cervical spine were obtained at four months postoperatively in all patients. Radiographs were used to evaluate postoperative lordosis. RESULTS Average length of follow up was 47 months. Nurick scores improved from an average of 2.3 preoperatively to postoperative scores of 1.5 (p>.05) at six months and 1.4 (p>.05) at two years. MUEF scores also improved at both the six month and two year intervals. All patients had improved canal diameter on post-operative MRI scan evaluation obtained four months post-operatively. CONCLUSION This study confirms that laminoplasty is a safe and effective treatment of cervical spondylotic myelopathy in the North American population. LEVEL OF EVIDENCE Case Series Level IV.

Is Preoperative Fibrinogen Testing Associated With Total Blood Loss in Adolescent Idiopathic Scoliosis Correction

STUDY DESIGN Retrospective analysis. OBJECTIVE This study sought to investigate the potential association between preoperative fibrinogen, bleeding, and transfusion requirements in adolescent idiopathic scoliosis (AIS) corrections. SUMMARY OF BACKGROUND DATA Blood loss after major spinal reconstruction increases the risks and costs of surgery. Preoperative fibrinogen levels may predict intra- and postoperative blood loss. METHODS Data were collected from clinic charts and hospital medical records of all 110 of a single surgeons consecutive AIS patients undergoing greater than three-level deformity correction surgeries from January 2011 to December 2013. Pearson test was used to investigate the correlation between bleeding and clinical variables, with level of significance set at α = 0.05. RESULTS Mean total bleeding volume was 488 (±356) mL. Overall, mean preoperative fibrinogen concentration was 188.6 ± 32.8 mg/dL. Preoperative platelet counts, prothrombin time (PT), and activated partial thromboplastin time (aPTT) did not correlate significantly with preoperative fibrinogen concentration (p > .05). Both packed red cells (PRC) and packed red blood cells (PRBC) correlated significantly with preoperative fibrinogen (p < .05). The correlation between PRC and preoperative fibrinogen was -0.042. There was a negative correlation between PRBC and preoperative fibrinogen (r = -0.46). Overall mean thromboelastography (TEG) values were within normal range in both males and females and both had comparable TEG parameter values. All the TEG variables (G, K, and Angle) correlated significantly with preoperative fibrinogen (p < .05) but not with total blood volume (p > .05). The correlation coefficient between these TEG variables and preoperative fibrinogen were 0.51, 0.59, and 0.54, respectively. The total bleeding volume and % estimated blood volume correlated significantly with both PRC (r = 0.352, r = 0.376; p < .05) and PRBC (r = 0.621, r = 0.614; p < .05). CONCLUSIONS In our cohort undergoing correction of AIS, preoperative fibrinogen levels exhibited a significant negative logarithmic correlation with total blood loss. TEG variables also correlated significantly with preoperative fibrinogen levels. Efforts should be made to incorporate this measure in perioperative blood management program for AIS corrections. LEVEL OF EVIDENCE Level IV.STUDY DESIGN Retrospective analysis. OBJECTIVE This study sought to investigate the potential association between preoperative fibrinogen, bleeding, and transfusion requirements in adolescent idiopathic scoliosis (AIS) corrections. Blood loss after major spinal reconstruction increases the risks and costs of surgery. Preoperative fibrinogen levels may predict intra- and postoperative blood loss. METHODS Data were collected from clinic charts and hospital medical records of all 110 of a single surgeons consecutive AIS patients undergoing greater than three-level deformity correction surgeries from January 2011 to December 2013. Pearson test was used to investigate the correlation between bleeding and clinical variables, with level of significance set at α = 0.05. RESULTS Mean total bleeding volume was 488 (±356) mL. Overall, mean preoperative fibrinogen concentration was 188.6 ± 32.8 mg/dL. Preoperative platelet counts, prothrombin time (PT), and activated partial thromboplastin time (aPTT) did not correlate significantly with preoperative fibrinogen concentration (p >.05). Both packed red cells (PRC) and packed red blood cells (PRBC) correlated significantly with preoperative fibrinogen (p <.05). The correlation between PRC and preoperative fibrinogen was -0.042. There was a negative correlation between PRBC and preoperative fibrinogen (r = -0.46). Overall mean thromboelastography (TEG) values were within normal range in both males and females and both had comparable TEG parameter values. All the TEG variables (G, K, and Angle) correlated significantly with preoperative fibrinogen (p <.05) but not with total blood volume (p >.05). The correlation coefficient between these TEG variables and preoperative fibrinogen were 0.51, 0.59, and 0.54, respectively. The total bleeding volume and % estimated blood volume correlated significantly with both PRC (r = 0.352, r = 0.376; p <.05) and PRBC (r = 0.621, r = 0.614; p <.05). CONCLUSIONS In our cohort undergoing correction of AIS, preoperative fibrinogen levels exhibited a significant negative logarithmic correlation with total blood loss. TEG variables also correlated significantly with preoperative fibrinogen levels. Efforts should be made to incorporate this measure in perioperative blood management program for AIS corrections. LEVEL OF EVIDENCE Level IV.