Incidence of Tether Breakage in Anterior Vertebral Body Tethering.

BACKGROUND: Thoracic anterior vertebral body tethering (TAVBT) is an emerging treatment for adolescent idiopathic scoliosis. Tether breakage is a known complication of TAVBT with incompletely known incidence. We aim to define the incidence of tether breakage in patients with adolescent idiopathic scoliosis who undergo TAVBT. The incidence of tether breakage in TAVBT is hypothesized to be high and increase with time postoperatively. METHODS: All patients with right-sided, thoracic curves who underwent TAVBT with at least 2 and up to 3 years of radiographic follow-up were included. Tether breakage between 2 vertebrae was defined a priori as any increase in adjacent screw angle >5 degrees from the minimum over the follow-up period. The presence and timing of tether breakage were noted for each patient. A Kaplan-Meier survival analysis was performed to calculate expected tether breakage up to 36 months. χ 2 analysis was performed to examine the relationship between tether breakage and reoperations. Independent t test was used to compare the average final Cobb angle between cohorts. RESULTS: In total, 208 patients from 10 centers were included in our review. Radiographically identified tether breakage occurred in 75 patients (36%). The initial break occurred at or beyond 24 months in 66 patients (88%). Kaplan-Meier survival analysis estimated the cumulative rate of expected tether breakage to be 19% at 24 months, increasing to 50% at 36 months. Twenty-one patients (28%) with a radiographically identified tether breakage went on to require reoperation, with 9 patients (12%) requiring conversion to posterior spinal fusion. Patients with a radiographically identified tether breakage went on to require conversion to posterior spinal fusion more often than those patients without identified tether breakage (12% vs. 2%; P =0.004). The average major coronal curve angle at final follow-up was significantly larger for patients with radiographically identified tether breakage than for those without tether breakage (31 deg±12 deg vs. 26 deg±12 deg; P =0.002). CONCLUSIONS: The incidence of tether breakage in TAVBT is high, and it is expected to occur in 50% of patients by 36 months postoperatively. LEVEL OF EVIDENCE: Level IV.

Long-term Results of Spine Stapling for AIS to Skeletal Maturity and Beyond.

BACKGROUND: We looked at long-term follow-up of spine stapling with Nitinol Staples. This was a cohort of all adolescent idiopathic scoliosis (AIS) patients with curves at high risk to progress based on curve magnitude, premenarchal status in all females, failure of brace treatment, and skeletal immaturity. METHODS: This is a single surgeon retrospective review of consecutive AIS patients treated with Nitinol staples for progressive scoliosis. Fourteen patients, 16 curves from 2005 to 2008 were eligible. Minimum curve for stapling was 30 degrees. Standard preoperative, intraoperative, and postoperative data were collected. All patients were followed for a minimum of 36 months and to skeletal maturity. Three groups were: improved (group 1), correction of any amount; minimal progression (group 2), progression ≤10 degrees; and failure (group 3), ≥10 degrees of progression. RESULTS: A total of 13 thoracic curves and 2 compensatory lumbar curves met the inclusion criteria (94%). Average follow-up was 61 months. The mean preoperative main thoracic curve was 35 degrees. All but 1 patients progressed at least 9 degrees in a brace prior to stapling. Females were all premenarchal, 10 patients were Risser 0 and 3 Risser 1. The average number of vertebrae stapled per curve was 6. Group 1 included 6 curves (40%). Group 2, 5 curves (33%). Group 3, 4 curves (27%). Three patients went on to uncomplicated fusion. Final curve measurement at the end of follow-up or before fusion (P=0.0037), curve progression (P≤0.001), and percentage of coronal correction on first postoperative standing radiograph (P=0.042) were the significant differences between groups 1+2 (successful) versus group 3 (failures). In total, 73% of this group either progressed ≤10 degrees or improved. CONCLUSIONS: This is the first study that follows AIS patients treated with spine stapling to skeletal maturity. Staples likely changed natural history in some of our patients. Initial percentage of correction on first standing postoperative PA x-rays was the only predictor of success. Stapling was safe without any long-term complications. LEVEL OF EVIDENCE: Level III-retrospective study.

Who Needs a Pediatric Intensive Care Unit After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis?

BACKGROUND: Hypotensive events (HEs) following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) can lead to delayed neurologic postoperative deficits (DNPD). This study aimed to determine the incidence of HEs (mean arterial pressure [MAP] <60 mmHg) after PSF for AIS and identify predictors for HEs. METHODS: Medical records of 99 consecutive patients who had PSF for AIS were retrospectively reviewed (2011-2013). Perioperative data were collected. Patients were divided into two groups based on MAP readings by an arterial line in the pediatric intensive care unit immediately postoperatively into postoperative day one: Group 1 (MAP ≥60 mmHg) and Group 2 (multiple occurrences of MAPs <60 mmHg). Mean values were compared using the independent t test. Multiple logistic regression was used to estimate the association of preoperative and intraoperative parameters with multiple HEs. RESULTS: Group 1 had 68 patients (68.7%) and Group 2 had 31 patients (31.3%). None of the compared parameters were associated significantly with multiple HE. However, patients who did not exhibit HEs within the first four hours postoperatively remained stable throughout the rest of the postoperative period. Only those with HEs in the first four hours experienced subsequent HEs in the first 24 hours. There were no DNPD or other major complications. CONCLUSION: Results showed that the incidence of HEs after PSF in AIS can be as high as 31.3%. We did not find any significant risk factors. Although DNPD after PSF is a rare complication and we had none in this series, we suggest that these patients with multiple HEs may be at risk for DNPD as a result of hypotension and potential for cord ischemia. Therefore, all patients after PSF should be monitored in a pediatric intensive care unit-type environment or postanesthesia recovery room initially. If stable for, at least, the initial four hours, then patients should be good candidates for a less intensive environment. LEVEL OF EVIDENCE: Level 3.

Screw Versus Hybrid Constructs for Flexible Thoracic Curves in Adolescent Idiopathic Scoliosis: A Prospective, Randomized Study.

STUDY DESIGN: Prospective, computer-randomized design. OBJECTIVE: Compare screw and hybrid constructs in flexible, thoracic curves for adolescent idiopathic scoliosis (AIS) in a prospective randomized fashion. SUMMARY OF BACKGROUND: The consensus in scientific literature is that all-screw constructs correct AIS better than hooks in the lumbar and in large, stiff thoracic curves. However, debate continues whether all-screw constructs outperform hybrid constructs in small, flexible thoracic AIS. To our knowledge, this is the first prospective, randomized scoliosis study that examines measures of correction and patient satisfaction with the Scoliosis Research Society-30 (SRS-30) questionnaire. METHODS: A total of 45 enrolled AIS patients with flexible, thoracic curves were given an identification number with an associated computer-generated randomization to the hybrid (n = 22) or screw group (n = 23). The treating surgeon received the randomization 2-3 days before surgery. Data including major Cobb (MC), truncal rotation (TR), rib index (RI), secondary curve (SC), and SRS-30 questionnaire were collected preoperatively and postoperatively at 4 weeks and 3, 6, 12, and 24 months. RESULTS: Thirty-seven patients in the hybrid (n = 18) and screw (n = 19) groups completed the study with a mean follow-up of 26 months (range, 24-49 months). Hybrid versus screw group means for preoperative, postoperative, and final follow-up were: MC 58° ± 8° versus 55° ± 6°, 18° ± 8° versus 15° ± 7°, and 23°± 8° versus 14° ± 6°; TR 14° ± 6° versus 16° ± 4°, 10° ± 5° versus 7° ± 3°, and 11° ± 5° versus 7° ± 4°; RI 3.0° ± 1.2° versus 3.4° ± 1.4°, 2.5° ± 0.7° versus 1.8° ± 0.6°, and 2.5° ± 0.8° versus 2.0° ± 0.5°; SC 35° ± 13° versus 31° ± 8°, 13° ± 11° versus 7° ± 9°, and 13° ± 12° versus 7° ± 7°; and SRS-30 3.9 ± 0.2 versus 3.9 ± 0.2, 4.1 ± 0.4 versus 4.0 ± 0.3, and 4.1 ± 0.3 versus 4.0 ± 0.2. CONCLUSIONS: Intergroup preoperative and early postoperative values were comparable (p > .05). At final follow-up, owing to loss of correction in the hybrid group, differences in MC (9°; p = .000), RI (0.54; p = .016), and TR (4°; p = .039) correction were statistically significant as SC trended toward significance (6°; p = .052). All-screw constructs outperformed hybrid constructs, especially over time. No differences in SRS-30 scores occurred between groups.

Long-term retrospective of the Kaneda anterior scoliosis system in thoracic adolescent idiopathic scoliosis.

BACKGROUND: Currently, the Kaneda anterior scoliosis system (KASS) is reported to be acceptable for the treatment of adolescent idiopathic scoliosis (AIS), particularly thoracolumbar and lumbar deformities. Its use in thoracic AIS is not as established. METHODS: Retrospective analysis of long-term results in patients treated with the KASS for thoracic AIS to determine specific factors associated with success or failure. We analyzed 16 consecutive patients who met the following criteria: thoracic AIS, anterior spinal fusion and KASS, and ≥24 months of follow-up or progression to failure, defined as the need for revision surgery or progression of the main thoracic curve (MTC) ≥50 degrees. Comparison of the MTC on the preoperative, postoperative, and final follow-up was the major evaluation criteria. On the basis of data analysis, patients were divided for comparison into 2 study groups: nonfailure group (n=11) and failure group (n=5). Statistical analysis was performed using paired and independent t tests. RESULTS: All curves were classified as Lenke 1 (n=14) and 2 (n=2). Mean age at surgery and levels fused were 14.6±2.7 years and 5±1 vertebrae, respectively. Mean follow-up was 4.2 years (range, 1.0 to 6.2 y). The failure group consisted of 5 patients that progressed to ≥50 degrees. In the nonfailure group, the mean MTC preoperative, postoperative, and at final follow-up were 52±8, 19±8, and 29±7 degrees, respectively. In the failure group, these measurements were 74±11, 35±8, and 56±12 degrees, respectively. CONCLUSIONS: This retrospective, long-term follow-up study found more KASS failures in thoracic AIS than previously reported. Even in the nonfailure group, 5 of the 11 patients progressed 10 degrees or more. Our results indicate an increased incidence of KASS failure with preoperative MTC curve ≥70 degrees. We consider an MTC≥70 degrees a likely contraindication for KASS instrumentation for thoracic AIS. Four of the 5 failures were fused short of the end vertebrae either proximally, distally, or both. Although short apical fusions were popular during the time these cases were done, fusion to the end vertebrae is an important principle for anterior fusions. Reaching the upper end vertebrae may be more difficult in these larger curves. We also recommend continued follow-up past 2 years as progression can occur after this time. LEVEL OF EVIDENCE: Retrospective comparative study, level III.

Unique case of polydactyly and a new classification system.

Polydactyly of the hands or feet is a common birth deformity. We recently encountered a female infant with a case of a crossed type 1 polydactyly with a mixed polydactyly of the feet. A mixed and crossed polydactyly is a rare finding with only one other reported case. This is the first report of crossed and mixed polydactyly of the feet presenting with 7 complete toes on each foot without syndactyly. In addition to a discussion of the treatment, this case has lead us to propose a more complete and less confusing classification system.

Early surgical repair of macrodactyly.

We report a case of macrodactyly of the foot in a 3-year-old girl. The standard treatment for this condition has been ablation. Studies of phalangeal resection, phalangeal amputation, syndactylization, digit shortening, tissue debulking, and osteotomy have shown varying results. In the case reported here, debulking combined with a shortening osteotomy was the treatment of choice. Although the pediatric patient may require additional surgeries because the deformity will continue to grow, early treatment has allowed this child the benefit of a functional, cosmetically appealing foot that can be fitted with normal footwear.

The effect of amicar on perioperative blood loss in idiopathic scoliosis: the results of a prospective, randomized double-blind study.

STUDY DESIGN: A prospective, randomized, double-blind Institutional Review Board-approved study evaluating the efficacy of Amicar (epsilon aminocaproic acid), an antifibrinolytic agent, in decreasing perioperative blood loss in idiopathic scoliosis. OBJECTIVES: To compare the perioperative (intraoperative and postoperative) blood loss and the need for autologous and homologous blood replacement in two groups of essentially identical patients undergoing a posterior spinal fusion for idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Reducing perioperative blood loss and the need for transfusion in patients undergoing spinal surgery is important to orthopedic surgeons. Recently, there has been interest in pharmacologic agents, particularly Amicar and Aprotinin, to assist in decreasing perioperative blood loss. In 2001, in a preliminary study, we demonstrated that Amicar appeared to be effective in reducing perioperative blood loss in patients with idiopathic scoliosis undergoing a posterior spinal fusion and segmental spinal instrumentation. This was a study of 28 consecutive patients receiving Amicar compared to a historical control group of the 31 previous consecutive patients with the same study criteria. The current study was performed to confirm our preliminary findings. METHODS: We analyzed the perioperative blood loss of 36 patients with idiopathic scoliosis who were blindly randomized by the operating room pharmacy into an Amicar and control group. The criteria to be included in the study was the same as the preliminary study: diagnosis of idiopathic scoliosis, age at surgery 11 to 18 years, posterior spinal fusion and segmental spinal instrumentation only, autogenous iliac crest bone graft or homologous cancellous bone graft, and a signed agreement to participate in the study. The patients in both groups had the same anesthetic technique, intraoperative procedure, instrumentation, postoperative management, and standardized indications for transfusions. RESULTS: Before surgery, the patients in both groups were essentially identical. The distribution of patients and their results was not known until the completion of the study. Patients in the Amicar group demonstrated a statistically significant decrease in perioperative blood loss and the need for autologous blood transfusion. Interestingly, this decrease was predominantly in the postoperative suction drainage. This may be due to elevated fibrinogen levels induced by Amicar. The patients taking Amicar had no intraoperative or postoperative thromboembolic complications. CONCLUSIONS: The results of this study confirmed that the use of intraoperative Amicar is a safe, effective, and inexpensive method to significantly reduce perioperative blood loss in patients with idiopathic scoliosis undergoing posterior spinal fusion and segmental spinal instrumentation. The results have allowed us to reduce our recommendation for perioperative autologous blood donation, thereby further decreasing costs.