3D Printing of CT Dataset: Validation of an Open Source and Consumer-Available Workflow.

The broad availability of cheap three-dimensional (3D) printing equipment has raised the need for a thorough analysis on its effects on clinical accuracy. Our aim is to determine whether the accuracy of 3D printing process is affected by the use of a low-budget workflow based on open source software and consumer's commercially available 3D printers. A group of test objects was scanned with a 64-slice computed tomography (CT) in order to build their 3D copies. CT datasets were elaborated using a software chain based on three free and open source software. Objects were printed out with a commercially available 3D printer. Both the 3D copies and the test objects were measured using a digital professional caliper. Overall, the objects' mean absolute difference between test objects and 3D copies is 0.23 mm and the mean relative difference amounts to 0.55 %. Our results demonstrate that the accuracy of 3D printing process remains high despite the use of a low-budget workflow.

Open patellar tendon avulsion from tibial tuberosity after ACL reconstruction successfully treated with suture anchors.

Patellar tendon rupture after anterior cruciate ligament (ACL) reconstruction is a rare complication which usually occurs in the early postoperative period during rehabilitation. The management of open avulsions from tibial tuberosity has not been clearly defined yet. We describe a previously unreported case of traumatic and open patellar tendon avulsion from tibial tuberosity one year following ACL reconstruction in an elite football player which was successfully treated with suture anchors.

Minimally invasive fixation in tibial plateau fractures using an pre-operative and intra-operative real size 3D printing.

The purpose of our study was to compare the outcome after minimally invasive reconstruction and internal fixation with and without the use of pre- and intra-operative real size 3D printing for patients with displaced tibial plateau fractures (TPFs). We prospectively followed up 40 consecutive adult patients with closed TPF who underwent surgical treatment of reconstruction of the tibial plateau with the use of minimally invasive fixation. Sixteen patients (group 1) were operated using a pre-operative and intra-operative real size 3D-model, while 24 patients (group 2) were operated without 3D-model printing, but using only pre-operative and intra-operative 3D Tc-scan images. The mean operating time was 148.2±15.9min for group 1 and 174.5±22.2min for group 2 (p=0.041). In addition, the mean intraoperative blood loss was less in group 1 (520mL) than in group 2 (546mL) (p=0.534). After discharge, all patients were followed up at 6 weeks, 12 weeks, 6 months, 1year and then every year post surgically and radiographic evaluation was carried out each time using clinical and radiological Rasmussen's score, with no significant differences between the two groups. Two patients (group 2) developed infection which resolved within 3 weeks after usage of antibiotics. Neither superficial nor deep infections were present in group 1. In all patients, no non-union occurred. No intraoperative, perioperative, or postoperative complications, such as loss of valgus correction, bone fractures, or metallic plate failures were detected at follow-up. In patients operated with the use of 3D-model printing, we found a significant reduction in surgical time. Moreover, the technique without a 3D-model increased the patient's and the surgeon's exposure to radiation.

3D Printed replica of articular fractures for surgical planning and patient consent: a two years multi-centric experience.

BACKGROUND: CT scanning with 3D reconstructed images are currently used to study articular fractures in orthopedic and trauma surgery. A 3D-Printer creates solid objects, starting from a 3D Computer representation. CASE DESCRIPTION: We report from two year of multicenter experience in 3D printing of articular fractures. DISCUSSION AND EVALUATION: During the study period, 102 patients (distal radius fractures, radial head, tibial plateau, astragalus, calcaneus, ankle, humeral head and glenoid) underwent 3D printing. The medical models were used by surgeons to appreciate the dislocation of fragments and the yielding of the articular surface. In addition, models were showed to patient as part of the acquisition of the informed consent before surgery. CONCLUSIONS: 3D printing of articular fractures are innovative procedures that achieve a preoperative tangible, highly useful evaluation of the fractures to plan intervention and educate patients.

Delayed bleeding and pelvic haematoma after low-energy osteoporotic pubic rami fracture in a warfarin patient: an unusual cause of abdominal pain.

Introduction. Acute abdominal pain may be the presenting symptom in a wide range of diseases in the elderly. Acute abdominal pain related to a delayed bleeding and pelvic haematoma after a low-energy pubic rami fracture is rare and can have important consequences; to the best of our knowledge, only one case has been previously described. Case Report. We present an unusual case of an 83-year-old woman taking warfarin for atrial fibrillation, admitted to the Emergency Department (ED) with acute abdominal pain and progressive anemia related to a delayed bleeding and pelvic haematoma 72 hours after a low-energy osteoporotic pubic rami fracture. Warfarin was withheld, anticoagulation was reversed by using fresh frozen plasma and vitamin K, and concentrated red blood cells were given. Haemoglobin level gradually returned to normal with a progressive resorption of the haematoma. Conclusion. Delayed bleeding and pelvic haematoma after osteoporotic pubic rami fracture should be considered in the differential diagnosis of acute abdominal pain in the elderly. This case indicates the need for hospital admission, careful haemodynamic monitoring, and early identification of bleeding in patients with "benign" osteoporotic pubic rami fracture, especially those receiving anticoagulants, to provide an adequate management and prevent severe complications.

Serious delayed hair toe tourniquet syndrome with bone erosion and flexor tendon lesion.

Hair toe tourniquet syndrome (HTTS) is an uncommon pediatric condition occurring when the toe is circumferentially strangulated by human hair or fibers. An 8-week-old little girl was admitted to the Emergency Department because of the worsening swelling in the right second and third toes, which had been been previously treated with a local antibiotic thinking of an infection. An unrecognized HTTS was leading the third toe to necrosis. An urgent release of the constricting band on the two toes was performed and bone erosion and partial flexor tendon lesion on the third toe were detected. We would like to raise awareness in the community and in colleagues about HTTS in children, because early recognition and urgent treatment are mandatory to provide an adequate management and prevent severe complications.

Ceramic liner fatigue fracture: 3-D CT findings in a late recurrent THA dislocation.

Dislocation is one of the most common complications of total hip arthroplasty (THA). To the authors' knowledge, late recurrent dislocation of a THA with a ceramic-on-ceramic coupling secondary to fatigue fracture of the ceramic liner has never been described. A 76-year-old woman with right hip osteoarthritis underwent cementless modular THA with a ceramic-on-ceramic coupling. Approximately 10 years postoperatively, she experienced right hip pain with no trauma, which resolved in 14 days. Family members reported that the patient had shown a progressive cognitive and muscular decline in the previous months. Six months later, the patient was admitted for THA dislocation, which was immediately reduced. Computed tomography revealed that the right acetabular component had a retroversion of 4° and an inclination angle of 45°. An orthopedic brace was applied, but dislocation recurred 2 days after discharge. A 3-dimensional CT reconstruction showed a fracture of the ceramic liner in the posterolateral region. The patient underwent revision surgery, and the ceramic liner breakage was confirmed. After removal of the acetabular components, a cemented polyethylene cup was implanted. The stability of the stem was verified. The existing modular neck was replaced with a chromium-cobalt neck, and a new ceramic head was applied. At 7-month follow-up, the patient had good functional recovery with no hip instability. Fatigue failure of a ceramic liner should be considered as responsible for late dislocation after ceramic-on-ceramic THA. As part of the diagnostic strategy, 3-dimensional CT reconstruction should be used to evaluate ceramic liner breakage.

Predicting failure after surgical fixation of proximal humerus fractures.

BACKGROUND: Several studies reported high failures rates after internal fixation of proximal humerus fractures. Loss of reduction and screw cut-out are the most common reasons for revision surgery. Several risk factors for failure have been described in the literature. The aim of the present study was to assess risk factors for failure after surgical fixation of unstable proximal humerus fractures in a multivariate setup. METHODS: Two different surgical techniques (PHILOS locking plate and Humerusblock) were used. In the PHILOS group, every kind of postoperative relative movement between the implant and the humeral head or shaft was defined as failure. In the Humerusblock group, postoperative movement between the humeral head and the shaft in terms of angulation or translational displacement was defined as failure. The following parameters were assessed: age, gender, cancellous bone mineral density (BMD) of the humeral head, fracture type, medial metaphyseal comminution, medial metaphyseal head extension, initial angulation of the humeral head in the frontal plane, initial anteversion of the humeral head, medial hinge displacement, maximum displacement of the tuberosities with respect to the head, surgical technique, anatomic reconstruction and restoration of the medial cortical support. RESULTS: The following parameters were found to have a significant influence on the failure rate: age, local BMD, anatomic reduction, and restoration of the medial cortical support. The failure rate significantly increased with the number of risk factors. CONCLUSION: Preoperative assessment of the local BMD and the patients' biological age as well as intraoperative anatomic reduction and restoration of the medial cortical support are the essentials for successful surgical fixation of proximal humerus fractures. Multifragmentary fracture patterns in old patients with low local BMD are prone for fixation failure. If the surgeon is not able to achieve anatomic reduction and restoration of the medial cortical support intraoperatively in this situation, adjustments such as augmentation or primary arthroplasty should be considered.