Youngbae B. Kim

Comparison of Radiographic Outcomes for the Treatment of Scoliotic Curves Greater Than 100 Degrees : Wires Versus Hooks Versus Screws

Study Design. A retrospective comparative study. Objective. To compare the efficacy and safety of several different anchors in the apical levels of scoliotic curves ≥100° using radiographic outcomes and clinical complications. Summary of Background Data. To the best of our knowledge, no reports have compared various anchors at the apical level for correction of scoliosis curves ≥100°. Methods. Sixty-eight scoliosis patients (44 neuromuscular, 21 idiopathic, and 3 congenital) with major curves ≥100° (mean, 112.7°; range, 100°-159°) who underwent segmental spinal instrumentation and fusion with different anchors in the apical level were analyzed. All patients had a minimum 2-year follow-up (mean, 4.0 years; range, 2.0–10.5) and were divided into Group W (sublaminar wires n = 26), Group H (hooks n = 18), Group A (anterior vertebral screws n = 7), and Group PS (pedicle screws n = 17) based on the type of apical anchor used. Radiographic parameters and complications were investigated. Results. The 4 groups did not demonstrate any significant differences in gender, age at surgery, preoperative major Cobb angle, or curve flexibility (all P > 0.05). However, the PS group demonstrated a shorter follow-up period compared with the other 3 groups (P < 0.05). The PS group demonstrated the greatest correction rate, smallest loss of correction (P < 0.05), and greatest amount of correction of the apical vertebral translation (P < 0.0005) at ultimate follow-up. There were 4 cases (5.9%) of pseudarthrosis (3 in Group W, 1 in Group H; P > 0.05), 6 cases (8.8%) of implant failure (4 in Group W, 2 in Group H; P > 0.05). Despite one (1.5%) intraoperative neurologic complication (differences among groups, P > 0.05), there was no permanent neurologic deficit. Conclusion. All 4 constructs were able to achieve and maintain acceptable correction safely without permanent neurologic deficit and all demonstrated acceptable implant failure rate. Pedicle screw constructs in the apical levels demonstrated the best coronal correction, smallest loss of correction, and greatest amount of apical vertebral translation correction of the major Cobb angle compared with the other constructs without neurologic complications.

The Morbidity of an Anterior Thoracolumbar Approach : Adult Spinal Deformity Patients With Greater Than Five-Year Follow-up

Study Design. Retrospective study. Objective. To analyze the complications and patient satisfaction related to an anterior thoracolumbar approach in the treatment of adult spinal deformity. Summary of Background Data. There is no long-term follow-up data on the effects of an anterior thoracolumbar approach on adult spinal deformity patients. Methods. A specific questionnaire was used to evaluate long-term follow-up (average, 10.3 years; range, 5–20.6) of 62 adult patients who underwent spinal deformity surgery performed through an anterior thoracolumbar approach. Twenty-six patients had over 10 years follow-up and 36 were between 5 and 10 years follow-up. The questionnaire was composed of detailed scar-related subquestions for pain, appearance, bulging, daily life, and patient’s personal opinion of surgery. Postoperative Oswestry Disability Index (scores) were also obtained. Results. The average age and number of anterior fusion levels were 47.9 (range, 20–74) and 5.6 (range, 2–12), respectively. Although 82.2% patients were satisfied with the results of their surgery, in general, many of the patients were dissatisfied with aspects related to their anterior incision. For the pain domain, 20 patients (32.3%, 6 with >10 years follow-up, 14 patients with 5 years follow-up) had pain over their thoracolumbar scar, which they rated as moderate to severe. Twenty-seven patients (43.5%) had bulging of their scar region, 4 were surgically indicated for repair, and 1 had multiple surgical repairs. Twelve patients (19.4%) felt they had a poor outcome related to the postoperative appearance of their anterior wound. Fifteen patients (24.2%) showed limitations in activities of daily living due to their anterior incision. Three patients with >10 years of follow-up and 4 with >5 years of follow-up felt they were getting worse. The average Oswestry Disability Index score was 25.0 ± 16.3 (range, 0–52) postoperative. Conclusion. This is the first long-term (minimum 5 years) follow-up study focusing on patient outcomes after an anterior thoracolumbar approach for adult spinal deformity treatment. This approach appears to be associated with an appreciable high rate of postoperative pain (32.3%), bulging (43.5%), and functional disturbance (24.2%). Therefore, surgeons should use caution when recommending this approach to future adult spinal deformity patients.

Free-Hand Pedicle Screw Placement During Revision Spinal Surgery : Analysis of 552 Screws

Study Design. A retrospective study. Objective. To evaluate the safety of free-hand pedicle screw placement during revision surgery at levels with a solid posterior fusion mass and/or identified pseudarthroses of the thoracic and lumbosacral spine. Summary of Background Data. Placement of pedicle screws into previous fusion masses or pseudarthrosis levels of the spine is challenging because of the loss of anatomic landmarks. We are aware of no study focusing on screw placement without any type of radiographic or navigational assistance. Methods. Thirty-seven patients underwent revision spinal surgery with posterior spinal instrumentation and fusion using 552 transpedicular screws by a single surgeon from 1994 to 2003. Among 552 screws, 184 were inserted into virgin levels, 60 were inserted into the vertebral body through previous screw holes, 208 were inserted into fusion masses, and 100 were inserted into pseudarthrosis levels. We used the quadrangulation method to gain pedicle access in a prior fusion mass after diligent exposure of any and all visible anatomic landmarks. All screws were analyzed using radiographs, intraoperative monitoring data, and clinical outcomes. Results. There were 29 women and 8 men. The mean age of patients at the time of surgery was 38 + 6 years (range, 8–75 years). Six screws were removed intraoperatively according to the triggered electromyography criteria and 4 of them were repositioned after checking the integrity of the pedicle by a careful probing technique (1.09%). Six screws were removed after checking the intraoperative radiographs and 5 screws were misplaced, as noted, in postoperative radiographs (1.99%). Two patients underwent revision surgery at 3 days and 6 weeks after initial surgery, respectively, for root decompression at the osteotomy site although screw positions were correct. Conclusion. The free-hand technique of thoracic and lumbosacral pedicle screw placement in revision spinalsurgery is reliable and safe when using the quadrangulation method of gaining pedicle access in a prior fusion mass or at pseudarthrosis levels.

Surgical Treatment of Adult Scoliosis : Is Anterior Apical Release and Fusion Necessary for the Lumbar Curve?

Study Design. A retrospective study. Objectives. To analyze radiographic and functional outcomes after posterior segmental spinal instrumentation and fusion (PSSIF) with and without an anterior apical release of the lumbar curve in adult scoliosis patients. Summary of Background Data. No comparison study on PSSIF of adult lumbar scoliosis with apical release versus without has been published. Methods. Forty-eight adult patients with lumbar scoliosis (average age at surgery 49.6 years, average follow-up 3.7 years) who underwent PSSIF were analyzed with respect to radiographic change, perioperative and postoperative complications, and Scoliosis Research Society (SRS) outcome scores. Twenty-three patients underwent an anterior apical release of the lumbar curve via a thoracoabdominal approach followed by PSSIF (Group I). The remaining 25 patients underwent a PSSIF of the lumbar curve followed by anterior column support at the lumbosacral region through an anterior paramedian retroperitoneal or posterior transforaminal approach (Group II). Results. Before surgery, Group I showed a somewhat larger lumbar major Cobb angle (63.2° vs. 55.9°, P = 0.07), and both groups demonstrated significant differences in lumbar curve flexibility (26.9% vs. 37.2%, P = 0.02) and thoracolumbar kyphosis (27.0° vs. 15.0°, P = 0.03). After surgery, at the ultimate follow-up, there were no significant differences in major Cobb angle, C7 plumbline to the center sacral vertical line (P = 0.17), C7 plumbline to the posterior superior endplate of S1 (P = 0.44), and sagittal Cobb angles at the proximal junction (P = 0.57), T10–L2 (P = 0.24) and T12–S1 (P = 0.51). There were 4 pseudarthroses in Group I and one in Group II (P = 0.02). Postoperative total normalized SRS outcome scores at ultimate follow-up were significantly higher in Group II (69% vs. 79%, P = 0.01). Conclusion. Posterior segmental spinal instrumentation and fusion without anterior apical release of lumbar curves in adult scoliosis demonstrated better total SRS outcome scores and no differences in radiographic parameters without differences in clinical complications. However, the use of BMP in some of these patients (44%) may have also contributed to these differences.

A central hook-rod construct for osteotomy closure: a technical note.

Study Design. A retrospective consecutive case series. Objective. To illustrate a new surgical technique for closing osteotomies in fixed sagittal imbalance patients, and to evaluate the radiographic outcomes and complications. Summary of Background Data. During an osteotomy site closure, various techniques were used, most of which involve patient positioning, rod cantilevering, extending the fixation points, allowing less correction, and compressing through pedicle fixation points. Most of these techniques place added stress on the spinal pedicle screw fixation points, which may lead to screw loosening and eventual fixation failure. We used a central compression hook–rod construct for osteotomy closure to avoid adding compression force to the pedicle screws. Methods. Twenty-three consecutive patients in whom fixed sagittal imbalance was treated with a lumbar pedicle subtraction osteotomy or multilevel Smith-Petersen Osteotomies (SPO) using a central compression hook–rod construct for osteotomy closure were analyzed. Compression hooks were inserted into the fusion mass above and below the osteotomy site and centrally attached to a short rod. Compression forces were applied to securely close the osteotomy site. The mean age was 49.0 years (range, 33–75 years). Diagnoses included 11 scoliosis, 10 degenerative sagittal imbalance, and 2 ankylosing spondylitis patients. All but 2 cases were revisions. Sixteen patients had a pedicle subtraction osteotomy, and 7 had multilevel SPOs. A radiographic and clinical analysis was performed to evaluate the efficacy and possible complications of this technique. Results. Overall, lumbar lordosis increased an average of 31° (range, 11°−68°) and local lordosis through the osteotomy site increased by an average of 28° (range, 3°−47°). The C7 sagittal plumbline improved an average of 109 mm (range, 11−240 mm). In all cases, the osteotomy closures were performed without screw loosening or loss of correction intraoperatively. There were no hook–rod construct failures, but one transient root paresis, which might be related to this method. There was no pseudarthroses or significant correction loss after surgery. Conclusion. A central hook–rod construct is a safe, quick, controlled, and effective method for spinal osteotomy site closure. It may add strength to the overall construct and avoids the placement of direct compression force on the main pedicle screw fixation points that may lead to screw loosening during the osteotomy site closure, and ultimately to fixation failure.