Efficacy and safety of VEPTR instrumentation for progressive spine deformities in young children without rib fusions

Abstract

This retrospective study analyses 23 children treated with vertical expandable prosthetic titanium rib (VEPTR) for correction of non-congenital early onset spine deformities. After the index procedure (IP), the device was lengthened at 6-month intervals. The average (av) age at the time of IP was 6.5 years (1.11-10.5). The av follow-up time was 3.6 years (2-5.8). Diagnosis included 1 early onset idiopathic scoliosis, 11 neuromuscular, 2 post-thoracotomy scoliosis, 1 Sprengel deformity, 2 hyperkyphosis, 1 myopathy and 5 syndromic. Surgeries (187) included 23 IPs, av 6.5 (4-10) device expansions per patient (149) and 15 unplanned surgeries. 23 complications (0.13 per surgery) included 10 skin sloughs, 5 implant dislocations, 2 rod breakages and 6 infections. Coronal Cobb angle was av 68 degrees (11 degrees -111 degrees ), at follow-up av 54 degrees (0 degrees -105 degrees). Pelvic obliquity was av 33 degrees (13 degrees -60 degrees ), at follow-up av 16 degrees (0 degrees -42 degrees ). T1 tilt was av 29 degrees (5 degrees -84 degrees ), two remained unchanged, the remainder improved 10 degrees -68 degrees. Sagittal plane: All but two had stable profiles, two hyperkyphosis of 110 degrees /124 degrees improved to 56 degrees /86 degrees. Space available for lung ratio was less than 90% in ten before the IP, improved in nine and deteriorated in one. Originally designed for thoracic insufficiency syndromes related to rib and vertebral anomalies, VEPTR proved to be a valuable alternative to dual growing rods for non-congenital early onset spine deformities. The complication rate was lower, the control of the sagittal plane and the pelvic obliquity was as good, but the correction of the coronal plane deformity was less than growing rods. However, VEPTR's spine-sparing approach might provoke less spontaneous spinal fusion and ease the final correction at maturity.

Fig. 1

a, b Preoperative spine pa/lateral standing. 6.4-Year-old boy (No. 1) with an infantile S-shaped scoliosis which progressed to 71° Cobb angle at the lumbar main curve despite full time bracing. Physiologic sagittal profile. c, d 3-Year follow-up after five expansion procedures. Brace free after treatment without restriction of physical activity led to a hitherto uneventful course with an actual Cobb angle of 47° (34% correction) and a maintained physiologic profile

Fig. 2

a, b Preoperative spine ap/lateral in a supine position. 5-Year-old boy (No. 12) with severe cerebral palsy with loss of sitting ability due to progressive kyphoscoliosis. Brace intolerance. c, d 1-Year follow-up after two expansions. Progression is halted with one rib-to-pelvis construct. Since the upper cradle shows cutting-through the very soft ribs and there is an imminent skin slough, it is decided to share loads with a second construct. e, f 4-Year follow-up after 7 and 1 change of construct. The coronal plane deformity has improved from initial 100° scoliosis to 70°, the sagittal profile is kept stable, pelvic obliquity and T1 tilt are significantly better. The boy is able to sit brace free in the wheelchair