The study describes a technique of tibial autograft to augment posterior instrumented spinal fusion in a population of paediatric patients with severe idiopathic, neuromuscular or syndromic scoliosis who are at a higher risk of postoperative pseudarthrosis and reports patient outcomes in terms of union rate, donor site morbidity and cost.

Patients were identified from a review of waiting list and operating room records between 2007–2014. Surgery was performed by the senior author. Information on patient demographics, underlying diagnosis, age at surgery, revision surgery and length of follow-up was obtained from clinic notes. Parents of children were followed up with a structured telephone questionnaire regarding ambulatory status, post-operative pain, infection, further surgery and general satisfaction.

Four hundred and nine patients underwent posterior instrumented spinal fusion, during the study period. Forty-two patients’ fusions were augmented with tibial graft, 40 of whom participated in the study. There were no cases of donor site infection, compartment syndrome, tibial fracture or perioperative mortality. In 85% of cases leg pain had resolved within 6 weeks, and 100% within 6 months of surgery. There were 6 cases of revision spinal surgery, 3 for infection, 2 for sacroiliac screw removal and 1 for sacroiliac screw revision. There were no clinical cases of spinal pseudarthrosis in this series. All parents were satisfied by the clinical outcome of both the tibial and spinal surgeries.

Spinal fusion utilising tibial autograft is advocated as a simple, safe and cost-effective method of providing significant structural autograft to support fusion for a population of patients with high risk of junctional pseudarthrosis. With the exception of transient post-operative pain, the procedure was without any serious donor site morbidity. The outcomes of this study were as expected and in keeping with previous reports.

Introduction: Hook displacement or pullout is a common complication compromising the stability of spinal instrumentation. The two most common causes are the loss of the optimal adjustment between hook and lamina during the connection of the implant to the rod and the displacement of the hook during correction maneuvers.

Therefore, a partially constrained rod-implant link was conceived allowing for free rotation in the sagittal plane while maintaining the possibility for transverse loading during correction maneuvers. One of the possible benefits of this system is the preservation of the adjustment between hook and lamina.

Purpose of Study: To compare the adjustment obtained between hook and lamina by using a partially constrained pivot link (PL), connecting the hook to the rod while allowing for rotation in the sagittal plane, versus the common fully constrained link (FCL) connecting the hook rigidly to the rod.

Methods: A plastic model of the lumbar spine was instrumented on one side with a L1 supralaminar hook and a L3 infralaminar hook. Seven lordotic configurations (range: −45° to −30°) were randomly assigned to the model. A prebent rod with a −41° lordosis between the fixation points was used for all tests. Compression was applied to the claw construct until the best fit between hooks and laminae was achieved. The PL hooks were secured to the rod by a top-loading clip system allowing for rotation in the sagittal plane until final fixation with an incorporated setscrew. The FCL hooks were secured to the rod with a top-loading plug screw. The length of the hook blade in contact with the lamina, the initial and final lordosis of the construct were measured.

Results: The mean length of the hook blade in contact with the lamina was 6.9 mm for the PL infralaminar hooks versus 4.2 mm for the FCL infralaminar hooks (p< 0.0005). There was no statistically significant correlation between the degree of initial lordosis and the amountof contact achieved by both the FCL and PL infralaminar hooks (FCL: r = −0.052; PL: r = −0.585).

Discussion: Using a partially constrained pivot link achieves a larger contact between hook and lamina than the common fully constrained link. This was statistically highly significant at the level of the strategically most important infralaminar hooks in a lordotic construct. Early clinical experience using a spinal instrumentation based on the pivot link principle in seventy patients seems to confirm the enhanced strength of fixation. Especially, the management of spinal deformities in patients with severe osteoporosis or dystrophic lesions of the spine is significantly improved. Significant implant volume reduction allows for the use of this system even in young children.

In order to define the prognostic factors in Perthes’ disease in children older than 12 years, we reviewed 15 patients at the end of growth who were aged 12.1 to 14 years at presentation. The patients with the worst long-term prognosis (Stulberg class V) were compared with the others for age, skeletal maturity and remaining growth (Oxford method), as well as Catterall and Waldenström classifications at presentation. A significant difference (p = 0.001) was found for remaining growth (25% in Stulberg class V and 35% in the others) and also for the results at the end of growth when the remaining growth was over 30%, since this allowed sufficient time for reformation and remodelling of the femoral head.