In major orthopaedic departments, typically several total knee systems are used. Each system requires several sets of instruments, each set with many trays of complicated and expensive parts. The logistics and costs of maintainance are considerable. Our overall goal is to investigate the feasibility of autoclavable single-use 3D printed instruments made from a polymeric material, used for any type of total knee design. The procedure will be standardized and adjustments easy to implement. Each set will be packaged individually, and used for a single case. There are many aspects to this study; in this part, the aims are to identify suitable materials for autoclavability and strength, and then to compare the accuracy of a novel design of 3D printed tibial cutting guide with a current metallic guide. Test samples were designed to simulate shapes in current instruments, such as mating pegs and holes, threaded screws, and slotted blocks. Each set was produced in biocompatible materials, ABS-M30i, VeroClear (MED610), Ultem1010, and Nylon 12. Each part was laser scanned, and then imaged virtually using a reverse engineering software (GeoMagic). Manual measurements of key dimensions were also made using calipers. The parts were autoclaved using a standardized protocol, 30 minutes at 250° F. All parts were re-scanned and measured to determine any changes in dimensions. To test for strength and abrasion resistance, the slotted blocks were pinned to sawbones model tibias, and an oscillating saw used to cut through the slot. A compact 3D printed tibial cutting guide was then designed which fitted to the proximal tibia and allowed varus-valgus, tibial slope and height adjustments. A small laser attached to the guide projected to a target at the ankle. Tests were made on 20 sawbones, and compared with 20 with a standard metal cutting guide. Digitization was used to measure the angles of the cuts.Introduction
Methods
Electrical stimulators are commonly used to accelerate fracture healing, resolve nonunions or delayed unions, and to promote spinal fusion. The efficacy of electrical stimulator treatment, however, remains uncertain. We conducted a meta-analysis of randomised sham-controlled trials to establish the effectiveness of electrical stimulation for bone healing. We searched MEDLINE, EMBASE, CINAHL and Cochrane Central to identify all randomised sham-controlled trials evaluating electrical stimulators in patients with acute fractures, non-union, delayed union, osteotomy healing or spinal fusion, published up to February 2015. Our outcomes were radiographic nonunion, patient-reported pain and self-reported function. Two reviewers independently assessed eligibility and risk of bias, performed data extraction, and rated overall confidence in the effect estimates according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Fifteen randomised trials met our inclusion criteria. Electrical stimulation reduced the relative risk of radiographic nonunion or persistent nonunion by 35% (95%CI 19% to 47%; 15 trials; 1247 patients; number needed to treat = 7; p < 0.01; moderate certainty). Electrical stimulation also showed a significant reduction in patient-reported pain (Mean Difference (MD) on the 100-millimeter visual analogue scale = −7.67; 95% CI −13.92 to −1.43; 4 trials; 195 patients; p = 0.02; moderate certainty). Limited functional outcome data showed no difference with electrical stimulation (MD −0.88; 95% CI −6.63 to 4.87; 2 trials; 316 patients; p = 0.76; low certainty). Patients treated with electrical stimulation as an adjunct for bone healing have a reduced risk of radiographic nonunion or persistent nonunion and less pain; functional outcome data are limited and requires increased focus in future trials.
The recent emergence of autologous blood concentrates, such as platelet rich plasma (PRP), as a treatment option for patients with orthopaedic injuries has led to an extensive debate about their clinical benefit. Our objective was to determine the effectiveness of autologous blood concentrates compared with control therapy in improving pain in patients with orthopaedic bone and soft tissue injuries. We conducted a systematic review of MEDLINE and EMBASE from 1996 and 1947, respectively, up to July 2010. Additional studies were identified by contacting experts, searching the bibliographies of the included studies as well as orthopaedic meeting archives. We included published and unpublished randomized controlled trials or prospective cohort studies that compared autologous blood concentrates with a control therapy in patients with an orthopaedic injury. Two reviewers, working in duplicate, abstracted data on study characteristics and protocol. Reviewers resolved disagreement by consensus.Purpose
Method
Endochondral ossification involves a well ordered sequence of cellular events. Chondrocytes change their morphology and functions and are ultimately removed by the process of apoptosis. A variety of apoptotic-related signals have been characterised. These include Fas receptor (FasR)/Fas ligand (FasL), p53 and Bcl family. However, there is little known regarding the activity of these signals in the process of fracture healing. The purpose of this study was to investigate mRNA expression of apoptotic signals using RNase protection assay (RPA) and immunohistochemistry in endochondral bone formation. BALB/C mice aged 8 to 10 weeks were used for this study. First, a transverse fracture was made in the right tibia. Mice were euthanised at 1, 2 and 3 weeks postfracture. The calluses were harvested and studied for the expression of caspase-8, a key enzyme of apoptosis, and apoptosis inducers: tumour necrosis factor-alpha (TNF-α) and its receptor p55, FasL and Fas receptor (FasR), and TNF-related apoptosis-inducing ligand (TRAIL). Four mice at each timepoint were used for immunostaining of fracture callus. Sections were incubated with primary antibody then labelled by avi-din-biotin complex method. Another four to ten tibiae were used for RPA. Fracture callus were harvested and snap frozen in liquid nitrogen. RNA was isolated by TRI reagent and BCP, and mRNAs expression of apoptotic signals were detected. At each timepoint, mRNA of caspase-8, TNF-α, p55, FasL,FasR and TRAIL were detected by RPA. Immunostainings clearly showed that those apoptotic-related proteins were expressed by callus chondrocytes. Cartilaginous callus is replaced by woven bone in endochondral ossification. In this process, chondrocytes should be removed by the process of apoptosis in which death factors are elaborated directly in both an autocrine and paracrine manner.