Comparison of off-the-shelf ß-tricalcium phosphate implants with novel resorbable 3D printed implants in mandible ramus of pigs.

Facial reconstructive surgery has already implemented the use of 3D printed Patient Specific Implants derived from CAD/CAM-based technologies as an alternative to preformed bone graft substitutes. 3D-printed patient-specific implants derived from CAD/CAM-based technologies are used in facial reconstructive surgery as an alternative to preformed bone graft substitutes. However, to minimize the invasiveness and long-term adverse effects of surgical interventions, the implant needs to exhibit exact fitting, porosity, density, and volume and be made from resorbable materials that allow ingrowth and formation of new bone tissue. Therefore, we present this pilot study using 3D-printed implants consisting of pure ß-TCP, produced using a novel technique that assures these properties. Eight pigs received 3D-printed truncated porous cone bone implants paired with either an off-the-shelve a chronOS (DePuy Synthes chronOS Vivify Preforms) preformed block (n = 4) or a no-implant void (n = 4) in a surgically created defect on each side of the angle of the mandible. After 6 months, CT data showed that all 3D-printed implants performed as well as did the off-the-shelve implants, with predicted osteointegration medially and laterally and with minimal gapping between the implants and native bone. The CT findings were confirmed by histological analysis that revealed that the 3D-printed implants together with the off-the-shelve implants were almost complete resorbed. Much of the resorbed volume had been replaced by vascularized compact bone, and fusion between newly formed bone and native bone was observed in all implants, further indicating that the 3D-printed implants and off-the-shelve implants performed equally well. Only soft tissue developed in the void control sites. Further studies are needed to confirm these initial findings.

Patient-reported outcome measures unbiased by loss of follow-up. Single-center study based on DaneSpine, the Danish spine surgery registry.

PURPOSE: The purpose of this study is to determine if there are any demographic and reporting differences between patients who respond and those who refuse to respond to postal questionnaires from the Danish national spine database, DaneSpine. METHODS: DaneSpine collects patient-reported data, completed before surgery and at 3 months, and at 1, 2, 5, and 10 years postoperatively. The database was launched at the Center for Spine Surgery and Research at Lillebaelt Hospital on June 1st, 2010. We performed a 1-year follow-up on non-responders during a 6-month period between the 1st of August 2013 until the 31st of January 2014 using a structured phone interview to collect patient-reported outcomes, some health information and reasons for non-response. RESULTS: Of the 506 patients who were 1-year post-operative, three did not have baseline data and six had died before the 1-year follow-up. Twenty-four patients had a second spine surgery and were re-enrolled in the database. These cases had not reached the 1-year follow-up period for the second spine surgery and were excluded from the analysis. Thus, 473 patients had reached 1-year follow-up. Of these, 57 (12 %) did not respond to postal questionnaires. A structured phone interview was performed on these 57 non-responders. Non-responders were in general, a decade younger than responders, a greater proportion were males and smokers. Apart from EQ-5D, there was no difference in patient satisfaction, improvement in back pain or leg pain between the responders and non-responders. CONCLUSIONS: Missing data from 12 % of patients do not seem to bias conclusions that can be drawn from the DaneSpine database at the Center for Spine Surgery and Research at Lillebaelt Hospital.

Investigation of particle-functionalized tissue engineering scaffolds using X-ray tomographic microscopy.

A low-density, porous chitosan/poly-(dl-lactide-co-glycolide) (PLGA) microparticle composite scaffold was produced by thermally induced phase separation followed by lyophilization, to provide a bicontinuous microstructure potentially suitable for tissue engineering and locally controlled drug release. PLGA particles were mixed into the chitosan solution and subsequent phase separation during chitosan solidification forced PLGA particles into chitosan phase (Plateau borders). The distributions of volume, surface area, and elongation of 15,422 inclusions of agglomerated PLGA particles were calculated and approximated with log-normal distribution functions from nanotomography reconstructions. Cluster analysis revealed a homogenous inclusion distribution throughout the scaffold. The spatial location and orientation of individual inclusions within the Plateau borders of the scaffold were determined and from these the nearest-neighbor inter-inclusion distance distribution calculated, showing a mean of 2.5 microm. The depth of the inclusions in Plateau borders peaks at 700 or 125 nm, respectively, indicating a step-wise drug release from inclusions successively exposed during scaffold decomposition. Particle diameter ranged from 400 nm to 3 microm and inclusion Feret lengths ranged from 800 nm to 12 microm. These findings on composite morphology and distribution of inclusions are fundamental for predicting scaffold deterioration and particle-mediated drug release during ex vivo and in vivo cell cultivation.

[Prevalence of idiopathic scoliosis in the municipality of Hillerod]. / Praevalens af idiopatisk skoliose i Hillerød Kommune.

Among Scandinavian paediatric spinal surgeons there has been a debate whether the prevalence of idiopathic adolescent scoliosis (AIS) has declined. We examined all children in the town of Hillerød, Denmark attending third and fifth grade (age 10 and 12) with forward-bending-test using a scoliometer. All children with more than seven degrees of trunk inclination were referred to a PA radiogram of the spine. We found a 0.4 percent prevalence of AIS with Cobbangles greater than 19 degrees. This is similar to earlier findings, suggesting that the declining referral rate is due to late detection of idiopathic adolescent scoliosis.

[Increasing incidence of clubfoot in the county of Frederiksborg]. / Stigende incidens af klumpfod i Frederiksborg Amt.

The incidence of congenital clubfoot in Frederiksborg County, Denmark, was studied over a period of 16 years (1979-1994). Altogether 60, 186 live infants were born, and of these 72 had a congenital clubfoot. Twenty-five children (35%) had bilateral clubfoot and 54 (75%) were boys. The overall incidence was 1.20 per thousand children. The incidence increased significantly during the observation period and was 2.41 per thousand in 1994. We cannot explain the rise in incidence.

Selection of fusion levels in idiopathic adolescent scoliosis treated by Harrington-DDT instrumentation: a short-term radiologic study.

Clinical records and radiographs of 106 patients treated by Harrington-dorsal transverse traction (DDT) instrumentation for idiopathic adolescent thoracolumbar scoliosis were reviewed. Our strategy was to fuse from one vertebra above the measured curve to two vertebrae below the curve, but to avoid fusions below the third lumbar vertebra. With this strategy, the lower level of fusion rarely coincided with the stable vertebra. In King type 2 and type 3 scolioses, the best results were obtained when the lower fusion level coincided with the stable vertebra. In King type 4 and in most King type 5 scolioses, the lower level of fusion was two or three vertebrae short of the stable vertebra; nevertheless, we obtained good corrections. We conclude that in King type 4 and type 5 scolioses extensive lumbar fusion can be avoided.

[Idiopathic scolioses]. / Idiopatiske skolioser.

The article summarizes the current theories on the aetiology, natural history, diagnosis and treatment of adolescent idiopathic scoliosis. Much remains unknown concerning the genesis of scoliosis. The current treatment with bracing or spinal fusion is effective.

[Surgical management of idiopathic scoliosis using Harrington DTT instruments]]. / Idiopatiske skolioser opereret a.m. Harrington-DTT.

We reviewed the clinical charts and roentgenogram of 111 patients operated with Harrington-DTT instrumentation for idiopathic adolescent scoliosis at Copenhagen University Hospital from 1983 to 1989. Male/female ratio was 1:9. Median age was 14.5 (11-21) years at the time of surgery. Median follow-up time was 4.0 (1-7) years. Of the 111 patients, complications were registered in fifteen. Seven were reoperated, four due to gliding of the upper hook, three due to fatigue fracture of the Harrington rod before union. We found no deep infections or persisting neurological damage.

[Idiopathic scolioses treated with the Boston brace]. / Idiopatiske skolioser behandlet med Boston-korset.

It is well known that Boston bracing may stop progression in many patients with minor curves. One hundred and thirty-eight patients were treated with the Boston brace for idiopathic scoliosis. Age was 14.1 +/- 1.6 years at the time of bracing, and the length of time spent in the brace was 2.6 +/- 1.0 years. The major curve at the time of bracing was 39 +/- 10 degrees, and 36 +/- 11 degrees at the time of follow-up in the patients who completed bracing. Thirty-six patients progressed, and were later fused. None of the patients with the apex of the curve between T11 and L1 required spinal fusion (p < 0.0001). No patients with curve magnitude on sidebending of less than 11 degrees needed spinal fusion. None of the patients who had a Harrington factor of less than five degrees per vertebra needed spinal fusion.