The tried-and-true treatment for progressive adolescent idiopathic scoliosis (AIS) is a posterior spinal fusion (PSF). However, for skeletally immature patients, there is increasing interest in motion-sparing growth modulation, specifically anterior vertebral body tethering (AVBT). Early reports on tethering looked promising, but the long-term prognosis remains fuzzy.
Newton et al. clarify this somewhat in the May 6, 2020 issue of JBJS. They retrospectively compared outcomes among a cohort of 23 AVBT patients followed for a mean of 3.4 years with those among a matched cohort of 26 PSF patients followed for a mean of 3.6 years. The groups were well-matched in terms of demographics and preoperative curve measurements, but the AVBT group was slightly less skeletally mature based on triradiate cartilage status and Sanders classification.
The authors found that both groups experienced significant postoperative curve correction, but the PSF group had significantly greater immediate correction of the main thoracic curve (78%) than the AVBT group (36%). Smaller immediate correction is to be expected in a growth-modulation procedure, which allows the spine to “grow straighter” over time with the tether. But at the final follow-up, the AVBT group had only a 43% curve correction versus 69% final follow-up correction in the PSF group. In addition, 9 revision procedures occurred in the AVBT group, versus none in the PSF group. Twelve patients (52%) in the AVBT group had evidence of broken tethers, with 3 of those patients undergoing revision surgery due to curve progression linked to tether breakage.
Overall, 12 of 23 patients in the AVBT group (52%) were deemed a “clinical success” at the end of the study (defined as a thoracic curve <35° without a need for a secondary fusion) while all 26 patients in the PSF group were deemed a clinical success. Anterior vertebral body tethering may have a role in the treatment of scoliosis in the growing spine, but the results to date, including these from Newton et al., lead me to question whether the tethering “juice” in its current form is worth the “squeeze.”
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of OrthoBuzz summaries of these “What’s New” articles. This month, co-author Kelly Vanderhave, MD selected the 5 most clinically compelling findings from the more than 50 studies summarized in the February 19, 2020 “What’s New in Pediatric Orthopaedic Surgery.”
—ACL reconstruction in pediatric patients continues to receive research attention. A recent review of >560 cases showed that soft-tissue grafts used in this population were twice as likely to fail (13%) as patellar tendon grafts (6%) (p <0.001).1
Septic Arthritis of the Hip
—A multicenter study identified the following independent risk factors for a repeat surgical procedure after initial arthrotomy for septic arthritis of the hip: presenting CRP of >10 mg/dL and ESR of >40 mm/hr, and the presence of osteomyelitis and MRSA.2
Adolescent Idiopathic Scoliosis
—A minimum 20-year follow-up of a cohort study evaluating 180 patients after observation, bracing, or surgical management of adolescent idiopathic scoliosis found the following:
- In the observation cohort, 5 of 36 patients underwent a scoliosis surgical procedure as an adult.
- In the bracing cohort, only 1 of 41 patients required an additional spinal surgical procedure.
- In the surgical cohort, 7 of 103 patients required a revision surgical procedure.
At a mean follow-up of 30 years, there were no significant differences in patient-reported outcomes between the 3 cohorts.3
Infection after Spinal Deformity Surgery
—A retrospective study of >600 pediatric patients who underwent spinal deformity surgery identified 2 independent risk factors among 11 cases of deep surgical site infection that occurred >3 months after the procedure:
- Nonidiopathic scoliosis (e.g., neuromuscular, congenital, and syndromic etiologies)
- High volume of crystalloid administered during surgery (mean of 3.3 ±1.2 L in the group with surgical site infections vs 2.4 ±1.0 L in the infected group)
Redosing antibiotics intraoperatively after 3 hours did not significantly influence the risk of infection.4
Hip Dislocations in Infants with CP
—Among 11 patients (15 hips) with spastic cerebral palsy whose preoperative mean acetabular index was 29°, surgical hip reconstruction (a combination of open reduction, adductor tenotomy, femoral osteotomy, and/or pelvic osteotomy) yielded the following results at a mean follow-up of 40 months:
- Mean migration index of 7%
- Mean acetabular index of 22°
- No instances of osteonecrosis
- 90% achievement and maintenance of hip reduction in those who underwent open reduction with or without pelvic or femoral osteotomy.5
- Ho B, Edmonds EW, Chambers HG, Bastrom TP, Pennock AT. Risk factors for early ACL reconstruction failure in pediatric and adolescent patients: a review of 561 cases. J Pediatr Orthop. 2018 Aug;38(7):388-92.
- Murphy RF, Plumblee L, Barfield WB, Murphy JS, Fuerstenau N, Spence DD, Kelly DM, Dow MA, Mooney JF 3rd. Septic arthritis of the hip-risk factors associated with secondary surgery. J Am Acad Orthop Surg. 2019 May 1;27(9):321-6.
- Larson AN, Baky F, Ashraf A, Baghdadi YM, Treder V, Polly DW Jr, Yaszemski MJ. Minimum 20-year health-related quality of life and surgical rates after the treatment of adolescent idiopathic scoliosis. Spine Deform. 2019 May;7(3):417-27.
- Du JY, Poe-Kochert C, Thompson GH, Son-Hing JP, Hardesty CK, Mistovich RJ. Risk factors for early infection in pediatric spinal deformity surgery: a multivariate analysis. Spine Deform. 2019 May;7(3):410-6.
- Refakis CA, Baldwin KD, Spiegel DA, Sankar WN. Treatment of the dislocated hip in infants with spasticity. J Pediatr Orthop. 2018 Aug;38(7):345-9.
The evidence favoring tranexamic acid (TXA) for reducing surgical blood loss is ample and growing, but until now robust data were sparse regarding its efficacy in the setting of adolescent idiopathic scoliosis surgery. In the December 5, 2018 issue of The Journal of Bone & Joint Surgery, Goobie et al. report on a randomized, blinded, placebo-controlled trial showing that, in that population, TXA reduced perioperative blood loss by 27%, compared with blood loss in a placebo group.
Even with recent advances in scoliosis surgical technique, blood transfusions are common. And, because transfusions are associated with significant morbidity and mortality, limiting operative blood loss and reducing the need for transfusion have become focal points for orthopaedic surgeons.
In this Level-I trial, >100 patients between the ages of 10 and 18 years undergoing elective posterior instrumented spinal fusion were randomized to receive either TXA (infusion of a 50-mg/kg loading dose and a 10-mg/kg/h maintenance dose) or normal saline (delivered in the same way and dose) during surgery. The TXA group demonstrated an overall 27% reduction in cumulative blood loss and a 2-fold reduction in the percentage of patients with clinically relevant blood loss (defined as >20 mL/kg).
The cumulative effect of reduced blood loss was enhanced over time, with the positive effect of TXA being most evident in procedures lasting >4 hours. None of the patients in the TXA group required a transfusion or developed side effects such as thromboembolism or seizures.
In an interesting sidenote, the authors asked the participating orthopaedic surgeons, who were blinded to the randomization, to guess which group each patient had been assigned to by evaluating the relative ooziness of the surgical field. The surgeons guessed correctly 72% of the time.
Overall, these findings prompted the authors to conclude that “the use of TXA as part of a multimodal blood management strategy, as was employed in this study, should be considered the standard of care for patients undergoing surgery for adolescent idiopathic scoliosis.”
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, OrthoBuzz asked Chad Krueger, MD, JBJS Deputy Editor for Social Media, to select the five most clinically compelling findings from among the more than 25 studies cited in the June 20, 2018 Specialty Update on Spine Surgery.
—A Level-III retrospective analysis found that patients who received a preoperative cervical epidural steroid injection prior to an anterior cervical discectomy and fusion or a posterior cervical fusion had a significantly greater risk of postoperative infection than those who did not receive a preoperative steroid injection.1 Prospective studies are needed to further clarify the perioperative infection risk associated with cervical epidural steroid injections.
—A Level-II randomized pilot trial comparing titanium-coated PEEK interbody spacers with non-coated PEEK spacers among 40 patients who underwent transforaminal lumbar interbody fusion found that patients in both groups had 92% fusion at 3 months, with no significant between-group differences in pain and disability outcomes.2
—A Level-II randomized study of 108 patients who underwent lumbar discectomy compared outcomes among those who experienced 2 weeks versus 6 weeks of postoperative activity restriction. At the 1-year follow-up there was a nonsignificant difference in recurrent herniation (11% in the 2-week group versus 7% in the 6-week group) and no significant between-group differences in pain or disability scores.3
RF Ablation for Chronic Low Back Pain
—A Level-II meta-analysis involving 454 patients with chronic low back pain found that those who underwent radiofrequency (RF) lumbar-facet denervation had significantly reduced VAS back pain compared to a group that underwent a sham procedure or epidural block. Those in the denervation group who benefited most were those who had responded favorably to an initial diagnostic facet block.4
Adolescent Idiopathic Scoliosis
—A Level-II study assessing the ability of surface topography to evaluate spinal deformity in children with adolescent idiopathic scoliosis followed 45 patients for 1 year. This method plus radiography allowed researchers to determine mild curves with strong negative predictive value and sensitivity. The authors estimated that surface topographic analyses could reduce patient exposure to ionizing radiation by eliminating 31% of surveillance radiographs in these patients.5
- Cancienne JM, Werner BC, Puvanesarajah V, Hassanzadeh H, Singla A, Shen FH, Shimer AL. Does the timing of preoperative epidural steroid injection affect infection risk after ACDF or posterior cervical fusion?Spine (Phila Pa 1976). 2017 Jan 15;42(2):71-7.
- Rickert M, Fleege C, Tarhan T, Schreiner S, Makowski MR, Rauschmann M, Arabmotlagh M. Transforaminal lumbar interbody fusion using polyetheretherketone oblique cages with and without a titanium coating: a randomised clinical pilot study. Bone Joint J.2017 Oct;99-B(10):1366-72.
- Bono CM, Leonard DA, Cha TD, Schwab JH, Wood KB, Harris MB, Schoenfeld AJ. The effect of short (2-weeks) versus long (6-weeks) post-operative restrictions following lumbar discectomy: a prospective randomized control trial. Eur Spine J.2017 Mar;26(3):905-12. Epub 2016 Nov 2.
- Lee CH, Chung CK, Kim CH. The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials. Spine J.2017 Nov;17(11):1770-80. Epub 2017 May 30.
- Hong A, Jaswal N, Westover L, Parent EC, Moreau M, Hedden D, Adeeb S. Surface topography classification trees for assessing severity and monitoring progression in adolescent idiopathic scoliosis. Spine (Phila Pa 1976).2017 Jul 1;42(13):E781-7.