FeMn and FeMnAg biodegradable alloys: An in vitro and in vivo investigation.

Iron-based biodegradable metal bone graft substitutes are in their infancy but promise to fill bone defects that arise after incidents such as trauma and revision arthroplasty surgery. Before clinical use however, a better understanding of their in vivo biodegradability, potential cytotoxicity and biocompatibility is required. In addition, these implants must ideally be able to resist infection, a complication of any implant surgery. In this study there was significant in vitro cytotoxicity caused by pure Fe, FeMn, FeMn1Ag and FeMn5Ag on both human foetal osteoblast (hFOB) and mouse pre-osteoblast (MC3T3-E1) cell lines. In vivo experiments on the other hand showed no signs of ill-effect on GAERS rats with the implanted FeMn, FeMn1Ag and FeMn5Ag pins being removed largely uncorroded. All Fe-alloys showed anti-bacterial performance but most markedly so in the Ag-containing alloys, there is significant bacterial resistance in vitro.

Next step trauma and orthopaedic surgery: integration of augmented reality for reduction and nail implantation of tibial fractures.

INTRODUCTION: There is a tremendous scope of hardware and software development going on in augmented reality (AR), also in trauma and orthopaedic surgery. However, there are only a few systems available for intra-operative 3D imaging and guidance, most of them rely on peri- and intra-operative X-ray imaging. Especially in complex situations such as pelvic surgery or multifragmentary multilevel fractures, intra-operative 3D imaging and implant tracking systems have proven to be of great advantage for the outcome of the surgery and can help reduce X-ray exposure, at least for the surgical team (Ochs et al. in Injury 41:1297 1305, 2010). Yet, the current systems do not provide the ability to have a dynamic live view from the perspective of the surgeon. Our study describes a prototype AR-based system for live tracking which does not rely on X-rays. MATERIALS AND METHODS: A protype live-view intra-operative guidance system using an AR head-mounted device (HMD) was developed and tested on the implantation of a medullary nail in a tibia fracture model. Software algorithms that allow live view and tracking of the implant, fracture fragments and soft tissue without the intra-operative use of X-rays were derived. RESULTS: The implantation of a medullar tibia nail is possible while only relying on AR-guidance and live view without the intra-operative use of X-rays. CONCLUSIONS: The current paper describes a feasibility study with a prototype of an intra-operative dynamic live tracking and imaging system that does not require intra-operative use of X-rays and dynamically adjust to the perspective of the surgeons due to an AR HMD. To our knowledge, the current literature does not describe any similar systems. This could be the next step in surgical imaging and education and a promising way to improve patient care.

The Necessity of CT Hip Scans in the Investigation of Occult Hip Fractures and Their Effect on Patient Management.

The diagnostic challenge of negative plain radiography in the context of a previously ambulatory patient is increasing with the rise in geriatric trauma. These patients are often diagnosed with small undisplaced fractures of the pelvis and femur which may not alter management. This study aims to assess the frequency at which computed tomography (CT) hip scans altered patient management and whether two X-ray projections of the hip affected fracture detection rate. All CT hip scans performed over a three-year period were identified retrospectively. Only CT hips pertaining to the identification of occult fractures were included in the study. A total of 447 (63.6%) CT hips were performed to exclude an occult fracture, which was only detected in 108 (24.1%) of the scans requested. The majority were subcapital (n = 58, 53.7%) or intertrochanteric (n = 39, 36.1%). There was no significant difference between fracture detection rates when comparing one and two views of the pelvis. 82.4% (n = 89) of occult hip fractures were managed operatively. CT imaging led to a change in patient management in 20% of cases. The frequency at which CT scan detects and alters management in occult hip fractures confirms the justification for its use. Increasing the number of X-ray projection views does not decrease the reliance on CT. Pelvic ring fractures are common in nonambulatory patients following trauma, and if confirmed on initial imaging, subsequent imaging to exclude a concurrent occult hip is unnecessary. The focus of further research should be towards the development of investigation algorithms which decrease the reliance on CT and defining the optimal surgical criteria for occult hip fractures.

Osteomyelitis in heterotopic ossification in a patient with congenital gigantism of the leg.

This paper presents the first report of osteomyelitis in heterotopic ossification in a patient with macrodystrophia lipomatosa. Careful review of magnetic resonance imaging allowed correct diagnosis and design of a limited surgical excision. Osteomyelitis should be considered in the differential diagnosis of pain and discharge when heterotopic ossification is present.

Bilateral Total Hip and Unilateral Knee Arthroplasties in a Young Adult with Arthropathy-Associated Intestinal Epithelial Dysplasia (Tufting Enteropathy).

Intestinal epithelial dysplasia (tufting enteropathy) is an uncommon congenital disorder. Furthermore, its association with chronic inflammatory arthropathy is rarely documented in the literature. Low prevalence rates of 1 in 100,000 live births in Western Europe exist, with higher rates in North Africa and Middle Eastern countries. Malta, being a small Mediterranean island at the cusp between Europe and North Africa, has an anecdotal sevenfold prevalence rate. This is the first documented case report of a patient with both intestinal epithelial dysplasia and severe bilateral hip and knee arthropathy that required simultaneous bilateral hip followed by, after a short interval, unilateral knee arthroplasties. Our aim is to highlight the rapid progression of associated arthropathy as well as the successful treatment with joint arthroplasties in such extreme cases. Surgical treatment may be a necessity despite best medical efforts to halt the disease.

Fibular non-union in distraction osteogenesis of the tibia.

INTRODUCTION: There is concern regarding potential non-union of the fibula following distraction osteogenesis and if non-union of the fibula leads to poor outcome. HYPOTHESIS: Assess the incidence of fibula non-union in patients undergoing distraction osteogenesis of the tibia and to report the effects on patient outcome. We also describe the management of this complication. MATERIALS AND METHODS: A consecutive series of patients undergoing distraction osteogenesis at a tertiary centre under a single surgeon. The amount of distraction, site of osteotomy, union of the fibula and tibia were recorded. RESULTS: Fifty-eight distraction procedures. Mean age was 37.2, 36 males and 22 females. Mean follow-up 23.4 months. 49 (84.5%) achieved fibula union at frame removal, and 9 (15.5%) went on to non-union. Of the fibulas that united, the mean lengthening was 9.25mm. In fibula non-union there was significantly greater lengthening (23.66mm) (p=0.004). Fifty-four (93.1%) of the tibias united following osteotomy and distraction, whilst 4 (6.9%) went onto non-union requiring operative treatment. Of the 4 tibias that did not unite, 3 (75%) also had fibula non-union (p=0.01). Three (33.3%) of the 9 fibulas that did not unite developed symptoms. Two of these required surgery in the form of fibula plating. Both of these patient's symptoms resolved following surgery. DISCUSSION: Fibula non-union is a relatively common complication following osteotomy in distraction osteogenesis. The length of fibula distraction and tibia non-union are significant risk factors. We recommend surgical intervention for those patients who have symptomatic fibula non-unions. LEVEL OF EVIDENCE: IV, case series.

A simple design for a stoma flange cutter.

Several stoma flange cutters have been described, however it appears that there is limited awareness of their existence by doctors, stoma care nurses or patients. In this article a simple design for a stoma flange cutter is described.