Aims

This aim of this study was to assess the feasibility of designing and introducing generic 3D-printed instrumentation for routine use in total knee arthroplasty.

Introduction

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.

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.

Purpose

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.

Introduction: The safety of simultaneous bilateral knee replacement (BTKA) remains controversial. Some studies have proposed a higher incidence of serious complications, even death, following BTKA whilst others refute the latter. The objective of this meta-analysis was to evaluate the safety of BTKA.

Methods: A computerized literature search was conducted to identify all citations, between 1966 to 2005, concerning BTKA. All the English-language abstracts were obtained. A multistage assessment was then used to identify articles fulfilling the inclusion criteria for the study. All randomized, prospective studies reporting the outcome of BTKA were included. Details of any reported data were extracted and extensive analysis of relevant variables carried out.

Results: 150 published articles pertaining to BTKA were identified of which 18 papers on 27,807 patients (44,684 knees) were included in the meta-analysis.10,734 cases were unilateral TKA, 16,378 were simultaneous BTKA and 458 were staged bilateral TKA with at least 3 months time duration between the surgical procedures. The complications analyzed were DVT, PE, cardiac events and mortality. The incidence of PE (OR=1.8), cardiac complications (OR=2.4), and mortality (OR=2.24) were higher after simultaneous BTKA. The incidence of DVT was LOWER in the group with simultaneous BTKA.

Discussion: Based on the findings of this meta-analysis, simultanous BTKA seems to carry a higher risk of serious cardiac complications, pulmonary complications, and mortality. This procedure should be reserved for the healthy and young patients.

Background: Metaphyseal fracture healing presents special biomechanical challenges in orthopaedic surgery. The void typically created by damage to the metaphyseal cancellous bone must usually be filled in order to recover the biomechanical integrity of the bone. While autologous bone grafting is a standard treatment for these fractures, bone graft substitutes delivered with or without pharmacologic agents may augment healing.

Hypothesis: Tricalcium phosphate (TCP) is a known osteoconductive bone filler and OP-1 an osteoinductive bone morphogenetic protein; both have been used in the past in diaphyseal fractures with success. PTH (parathyroid hormone) has been recently shown to enhance osteoblastic activity, to have a net anabolic effect on bone mass, and to enhance healing of diaphyseal fractures. Each of these agents may also enhance healing of metaphyseal fractures.

Objective: The potential of all above factors to accelerate metaphyseal fracture healing has been evaluated in a new metaphyseal fracture model developed in our laboratory in a rabbit model.

Material and Methods: A metaphyseal wedge osteotomy was created in the distal tibia of 16-week-old female New Zealand White rabbits (n=20). The osteotomy was bridged with a custom-made external fixator. The osteotomy gap was filled with TCP containing OP-1 (n=4), TCP alone with daily subcutaneous injections of 10μg/Kgr BW PTH (n=4), or TCP alone with daily subcutaneous administration of 40μg/Krg BW PTH (n=4). Two control groups, TCP alone (n=4) and normal healing (n=4), were also included. Assessment methods included biomechanical testing in both compression and torsion, radiographic examination, and QCT scans.

Results: Healing was observed in both PTH treated groups as well as in the OP-1 group at 4 weeks post-surgery. PTH appeared to have a systemic effect on bone formation, whereas the effect of OP-1 was local to the osteotomy site. In comparison, healing was delayed in the normal healing and TCP alone groups.

Conclusion: PTH and OP-1 both enhance metaphyseal fracture healing. The different systemic vs. local effects of these two agents, suggest that PTH and OP-1 may have potential synergism in accelerating healing of metaphyseal fractures.

Introduction and Aims: Periprosthetic bone loss is responsible for the majority of cases of implant failure after total joint arthroplasty. Bisphosphonates are effective in reducing bone loss in many conditions associated with accelerated bone turnover. Our aim was to determine the effect of bisphosphonates on periprosthetic bone mineral density (BMD, g/cm2) after total joint arthroplasty.

Method: We conducted computerised searches for randomised controlled trials, evaluating the effects of bisphosphonates on periprosthetic bone mineral density in patients undergoing primary total joint arthroplasty. We searched MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews and the United Kingdom National Research Register Web-site to November 2003. Computerised searches of the archives of AAOS Annual Meetings 1989–2003 were also conducted. Additional strategies to identify articles included a hand search of the bibliographies of relevant articles and direct contact with the authors.

Results: Of 386 citations initially identified, nine citations met our eligibility criteria. The total number of randomised controlled trials was six (five published and one abstract). Four trials evaluated total hip arthroplasty and two examined total knee arthroplasty. Five trials used alendronate and one used pamidronate. Quality scores ranged from 65 to 75. The pooled sample size was 290 patients. Less periprosthetic bone loss occurred in the intervention group compared to the control group at the following follow-up intervals: three months (n=128, Weighted Mean Difference (WMD): 3.3%, 95% Confidence Interval (CI): 1.9–4.7, p< 0.01); six months (n=224, WMD: 4.5%, CI: 1.6–7.4, p< 0.001); and 12 months (n=173, WMD: 4.2%, CI: 1.5–6.9, p=0.03). Tests of heterogeneity revealed greater maintenance of BMD in cemented arthroplasty than in uncemented arthroplasty (WMD: 7.5%, CI: 4.3–10.7 versus WMD: 2.1%, CI: 0.61–3.6, respectively, p< 0.001) at 12 months follow-up.

Conclusion: Bisphosphonates have a beneficial effect on maintaining periprosthetic bone stock compared to control after total joint arthroplasty. The effect seems greater in cemented arthroplasty and total knee arthroplasty. Whether this increase in BMD results in improved fixation and longevity of prosthetic components remains unanswered. Larger trials evaluating the effect of bisphosphonates on rates of implant loosening and functional outcomes are needed.

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.