Patient-specific 3D printing to replace components of a rib-to pelvis "Eiffel Tower" vertebral expanding prosthetic titanium rib system in an infant: a case report.

PURPOSE: To address the anatomical challenges facing complex and revision spinal surgery, patient-specific 3D-printed models (3D-PMs) have received growing attention worldwide, primarily in adults. We report the use of a 3D-PM in the treatment of a case of wound breakdown over a component of a VEPTR (Vertical Expandable Prosthetic Titanium Rib; DePuy-Synthes) system, requiring replacement of Dunn-McCarthy hook and sleeve with components contoured to a patient-specific 3D-PM of the spine. METHOD: A two-year-old born with myelomeningocele (MMC), repaired at birth, developed progressive MMC-associated kyphoscoliosis. Elective insertion of a rib-to-pelvis 'Eiffel Tower' bilateral VEPTR growing rods construct was performed without initial complication. Prominence of the right VEPTR sleeve and Dunn-McCarthy hook side-to-side connector resulted in breakdown of overlying poor-quality soft tissues, necessitating washout, partial implant removal, intravenous antibiotic therapy and delayed primary wound closure. A patient-specific 3D-PM, utilising pre-operative CT spine and pelvis 3D-reconstructions, allowed pre-operative formation of a contoured implant, which was inserted without need for further revision. RESULTS: The patient underwent further VEPTR lengthening without recurrent infection, wound breakdown or implant failure at 24-month follow-up. Satisfactory control of the deformity has been achieved with continued improvement in sitting height and radiographic indices. CONCLUSION: This case illustrates the possibility, in certain cases, of using 3D-PM to develop complex components of spinal implant systems pre-operatively, removing the time and difficulty of intra-operative contouring. Consequently, custom-contoured implants may be produced, sterilised and implanted. This technique may be an option, in infants, including MMC-associated kyphoscoliosis, where midline fixation is not possible.

Case series of intradural disc in recurrence of lumbar disc prolapse.

Intradural disc herniation is a rare entity reported at 0.04-1.1% that occurs most commonly in the lumbar spine particularly at L4-L5 region. There is a paucity of literature due to the rarity of this condition. Intradural disc herniations must be considered in the differential diagnosis of prolapsed intervertebral disc disease especially with recent worsening of symptoms and mismatch of unenhanced magnetic resonance induction (MRI) findings. The confirmation is made with intraoperative findings. An intradural disc herniation is most often diagnosed intraoperatively. Contrast enhanced MRI scan is mandatory for pre-operative diagnosis. We report on two cases presenting to our unit in the form of recurrent intradural disc disease following previous lumbar surgery occurring within 3 months of the index procedure in both cases.