An In-Vitro Comparison of Mixed Reality Navigation to Traditional Freehand and Patient Specific Instrumentation Techniques for Glenoid Guide Pin Insertion during Shoulder Arthroplasty.

BACKGROUND: Accurate insertion of the glenoid guide pin in shoulder arthroplasty (RSA) is important for obtaining optimized glenoid component position and orientation. The objective of this study was to evaluate and compare the accuracy of three glenoid guide pin insertion techniques: 1) traditional software planning using freehand guide pin insertion (freehand), 2) guide pin insertion utilizing patient-specific instrumentation (PSI), and 3) using a mixed reality navigation (MR-NAV) system. METHODS: Twenty (20) computer tomography (CT) scans were obtained from patients exhibiting glenoid erosion patterns according to the Walch and Favard classifications. Cases were planned using validated three-dimensional (3D) preoperative planning software. The CT data was then used to 3D print triplicate plastic models of each glenoid to evaluate the three guide pin insertion techniques. The first technique employed traditional software planning with freehand guide pin insertion. The second method used preoperatively planned PSI guides, while the third utilized a MR-NAV system, which provided real-time holographic guidance during guide pin insertion. Once all guide pins had been inserted into the models, an independent optical tracking system and custom digitization device was used to quantify the position and orientation of each guide pin relative to the glenoid. The outcomes for this study included the absolute mean error in guide pin inclination, version, and entry point relative to the preoperative plan. The absolute Total Global Error was also assessed, which was defined as the sum of the absolute guide pin orientation and position error relative to the preoperative plan. RESULTS: No statistically significant differences between MR-NAV and PSI were found for the inclination error (2±1° versus 2±1°; P=0.056), version error (1±1° versus 1±1°; P=1.000), and Total Global Error (5±1 [mm+deg] versus 5±1 [mm+deg], P=1.000), respectively. The freehand technique produced significantly greater error than MR-NAV and PSI for inclination (5±3°, P≤0.017), version (4±3°, P≤0.032) and Total Global Error (8±3 [mm+deg], P<0.001). No statistically significant differences in the entry point error were observed between all guide pin insertion methods (P≥0.058). DISCUSSION: These results demonstrate that the precision and accuracy of MR-NAV is comparable to PSI and superior to a freehand technique for glenoid guide pin insertion in-vitro. Further study is needed to compare the accuracy of these techniques intra-operatively, in addition to assessing a potential learning curve between surgeons of varying experience with the MR-NAV system.

The Kouvalchouk Procedure versus Distal Tibial Allograft for Treatment of Posterior Shoulder Instability: The Deltoid "Hammock" Effect Exists.

BACKGROUND: In 1993, Kouvalchouk described an acromial bone block with a pedicled deltoid flap for the treatment of posterior shoulder instability. This procedure provides a "double blocking" effect in that the acromial autograft restores posterior glenoid bone loss and the deltoid flap functions as a muscular "hammock" resembling the sling effect of the conjoint in the Latarjet procedure. The primary aim of this study was to compare the Kouvalchouk procedure to distal tibial allograft (DTA) reconstruction for the management of posterior shoulder instability with associated bone loss, while the secondary aim was to evaluate the deltoid hammock effect. s METHODS: Ten upper extremity cadavers were evaluated using a validated shoulder testing apparatus in 0° and 60° of glenohumeral abduction in the scapular plane. Testing was first performed on the normal shoulder state and was followed by the creation of a 20% posterior glenoid defect. Subsequently, the Kouvalchouk and DTA procedures were conducted. Forces of 0N, 5N, 10N and 15N were applied to the posterior deltoid tendinous insertion on the Kouvalchouk graft along the physiological muscle line-of-action to evaluate the 'hammock" effect of this procedure. Testing was additionally performed on the Kouvalchouk bone graft with the deltoid muscle sectioned from its bony attachment. For all test states, a posteriorly directed force was applied to the humeral head perpendicular to the direction of the glenoid bone defect, with the associated translation quantified using an optical tracking system. The outcome variable was posterior translation of the humeral head at an applied force magnitude of 30N. RESULTS: The Kouvalchouk procedure with the loaded deltoid flap (10N: P=0.039 and 15N: P<0.001) was significantly better at reducing posterior humeral head translation than the DTA. Overall, increased glenohumeral stability was observed with increased force applied to the posterior deltoid flap in the Kouvalchouk procedure. The 15N Kouvalchouk was most effective at preventing posterior humeral translation, and the difference was statistically significant compared with the 20% glenoid defect (P=0.003), detached Kouvalchouk (P<0.001), and 0N Kouvalchouk (P<0.001). The 15N Kouvalchouk procedure restored posterior shoulder joint stability to near normal levels, such that it was not significantly different from the intact state (P=0.203). CONCLUSIONS: The Kouvalchouk procedure with load applied to the deltoid was found to be biomechanically superior to the DTA for the management of posterior shoulder instability with associated bone loss. Additionally, the results confirmed the presence and effectiveness of the deltoid "hammock" effect.

Outcomes of reverse shoulder arthroplasty in patients under 55 years old: Results from the New Zealand joint registry.

Background: The appropriate age at which to perform reverse shoulder arthroplasty is controversial. The aim of this study was to compare the outcomes of reverse shoulder arthroplasty between younger and older patients. Methods: Patients who underwent primary reverse shoulder arthroplasty between January 2000 and December 2019 were identified from New Zealand Joint Registry records. Patients were stratified into two cohorts according to age at the time of surgery: < 55 years and ≥ 55 years. These two groups were then compared with regard to baseline characteristics, indications for surgery, revision rates, and patient-reported outcomes using the Oxford Shoulder Score and American Shoulder and Elbow Score (ASES). Results: A total of 5518 primary reverse shoulder arthroplasty cases were identified, with 75 patients < 55 years at the time of surgery (range: 34-54 years). The mean duration of follow-up was 2.36 years (range: 0.11-13.37 years) in the younger cohort and 3.10 years (range: 0.01-16.22 years) in the older patient cohort. Indications for surgery differed significantly between the two groups, with younger patients having higher rates of inflammatory arthritis (p < 0.001), posttraumatic arthritis (p < 0.001), and avascular necrosis (p = 0.049). The younger cohort had an inferior 6-month postoperative Oxford Shoulder Score compared to the older cohort (mean: 28.5 [younger cohort] vs. 35.7 [older cohort]; p < 0.001). There was no significant difference in revision rate between the younger and older patient cohorts during the study period (1.56 [<55 years] vs. 0.74 [≥55 years] revisions per 100 component-years; p = 0.332). Conclusion: Our early results suggest that younger patients undergoing reverse shoulder arthroplasty demonstrate high implant retention rates, comparable to older patients. Longer-term patient-reported outcomes in younger patients are required to guide appropriate patient selection for reverse shoulder arthroplasty. Level of evidence: Level III, retrospective case-control study.

Short-term outcomes following 159 stemmed pyrolytic carbon shoulder hemiarthroplasties and how they compare with conventional hemiarthroplasties and total shoulder arthroplasties in patients younger than 60 years with osteoarthritis: results from the New Zealand National Joint Registry.

BACKGROUND: Despite the increasing use of pyrolytic carbon (pyrocarbon) hemiarthroplasty (PyCHA), clinical data reporting on its outcomes remain scarce. To date, no studies have compared the outcomes of stemmed PyCHA vs. conventional hemiarthroplasty (HA) and anatomic total shoulder arthroplasty (aTSA) in young patients. The primary aim of this study was to report on the outcomes of the first 159 stemmed PyCHAs performed in New Zealand. The secondary aim was to compare the outcomes of stemmed PyCHA vs. HA and aTSA in patients aged <60 years with osteoarthritis. We hypothesized that stemmed PyCHA would be associated with a low revision rate. We further hypothesized that in young patients, PyCHA would be associated with a lower revision rate and superior functional outcomes compared with HA and aTSA. METHODS: Data from the New Zealand National Joint Registry were used to identify patients who underwent PyCHA, HA, and aTSA between January 2000 and July 2022. The total number of revisions in the PyCHA group was determined, and the indications for surgery, reasons for revision, and types of revision were recorded. In patients aged <60 years, a matched-cohort analysis was performed comparing functional outcomes using the Oxford Shoulder Score (OSS). The revision rate of PyCHA was compared with that of HA and aTSA, calculated as revisions per 100 component-years. RESULTS: In total, 159 cases of stemmed PyCHA were performed and 5 cases underwent revision, resulting in an implant retention rate of 97%. Among patients aged <60 years with shoulder osteoarthritis, 48 underwent PyCHA compared with 150 who underwent HA and 550 who underwent aTSA. Patients treated with aTSA had a superior OSS compared with PyCHA and HA patients. The difference in the OSS between the aTSA and PyCHA groups exceeded the minimal clinically important difference of 4.3. There was no difference in revision rates between the groups. CONCLUSIONS: This study represents the largest cohort of patients treated with PyCHA and is the first to compare stemmed PyCHA with HA and aTSA in young patients. In the short term, PyCHA appear to be a promising implant with an excellent implant retention rate. In patients aged <60 years, the revision rate is comparable between PyCHA and aTSA. However, aTSA remains the implant of choice to optimize early postoperative function. Further studies are required to elucidate the long-term outcomes of PyCHA, particularly how they compare with those of HA and aTSA in young patients.

Basic calcium phosphate crystals induce the expression of extracellular matrix remodelling enzymes in tenocytes.

OBJECTIVES: Basic calcium phosphate (BCP) crystals contribute to several syndromes associated with tendon disease, including acute calcific tendinitis and Milwaukee shoulder syndrome. Interactions between BCP crystals and tenocytes (tendon cells) may contribute to these clinical syndromes. This study aimed to determine the direct effects of BCP crystals on tenocyte function and viability. METHODS: In vitro assays were used to assess changes in human tenocytes cultured with BCP crystals. Real-time PCR was used to determine changes in the expression of tendon-related genes and extracellular matrix remodelling enzymes (MMPs; a disintegrin and metalloproteases, ADAMTS; and tissue inhibitor of metalloproteinases, TIMPs). ELISA was used to measure protein concentrations in tenocyte supernatants. MTT and alamarBlue™ assays were used to determine changes in cell viability. RESULTS: BCP crystals upregulated tenocyte gene expression of MMP-1, MMP-3, ADAMTS-4 and TIMP-1 after 24 h. Time-course experiments showed expression peaked at 8 h for TIMP-1 and 48 h for MMP-1 and ADAMTS-4. Cyclooxygenase (COX)-1 gene expression was upregulated after 48 h. Tenocytes did not alter expression of scleraxis and tendon collagens, and expression of pro-inflammatory cytokines was not induced with BCP crystals. BCP crystals increased tenocyte release of prostaglandin E2 (PGE2) and MMP-1 protein after 24 h. However, neither COX-1 inhibition nor COX-2 inhibition led to consistent change in BCP crystal-induced tenocyte gene expression of extracellular matrix remodelling enzymes. BCP crystals had no effect on tenocyte viability. CONCLUSION: BCP crystals induce extracellular matrix remodelling enzymes, but not inflammatory cytokines, in tenocytes.

Factors secreted by monosodium urate crystal-stimulated macrophages promote a proinflammatory state in osteoblasts: a potential indirect mechanism of bone erosion in gout.

BACKGROUND: Tophi are lesions commonly present at sites of bone erosion in gout-affected joints. The tophus comprises a core of monosodium urate (MSU) crystals surrounded by soft tissue that contains macrophages and other immune cells. Previous studies found that MSU crystals directly reduce osteoblast viability and function. The aim of the current study was to determine the indirect, macrophage-mediated effects of MSU crystals on osteoblasts. METHODS: Conditioned medium from the RAW264.7 mouse macrophage cell line cultured with MSU crystals was added to the MC3T3-E1 mouse osteoblastic cell line. Conditioned medium from the THP-1 human monocytic cell line cultured with MSU crystals was added to primary human osteoblasts (HOBs). Matrix mineralization was assessed by von Kossa staining. Gene expression was determined by real-time PCR, and concentrations of secreted factors were determined by enzyme-linked immunosorbent assay. RESULTS: In MC3T3-E1 cells cultured for 13 days in an osteogenic medium, the expression of the osteoblast marker genes Col1a1, Runx2, Sp7, Bglap, Ibsp, and Dmp1 was inhibited by a conditioned medium from MSU crystal-stimulated RAW264.7 macrophages. Mineral staining of MC3T3-E1 cultures on day 21 confirmed the inhibition of osteoblast differentiation. In HOB cultures, the effect of 20 h incubation with a conditioned medium from MSU crystal-stimulated THP-1 monocytes on osteoblast gene expression was less consistent. Expression of the genes encoding cyclooxygenase-2 and IL-6 and secretion of the proinflammatory mediators PGE2 and IL-6 were induced in MC3T3-E1 and HOBs incubated with conditioned medium from MSU crystal-stimulated macrophages/monocytes. However, inhibition of cyclooxygenase-2 activity and PGE2 secretion from HOBs indicated that this pathway does not play a major role in mediating the indirect effects of MSU crystals in HOBs. CONCLUSIONS: Factors secreted from macrophages stimulated by MSU crystals attenuate osteoblast differentiation and induce the expression and secretion of proinflammatory mediators from osteoblasts. We suggest that bone erosion in joints affected by gout results from a combination of direct and indirect effects of MSU crystals.

Age-related differences in hamstring tendon used as autograft in reconstructive anterior cruciate ligament surgery.

PURPOSE: The hamstring tendon is the most commonly used autograft material in reconstructive surgeries of anterior cruciate ligament (ACL) tears. Younger patients have worse surgical outcomes, with a higher risk of re-rupture. We hypothesized that age-related changes in hamstring tendon properties affect the tendon's propensity to rupture when used as an autograft in ACL reconstructions. The purpose of this study was to compare hamstring tendon samples obtained from people aged 20 years or younger to samples obtained from older people. METHODS: Superfluous hamstring tendon material was collected from 13 young donors (aged 16-20 years) and 17 older donors undergoing ACL reconstructive surgery. Sections of the tendon samples were used for biomechanical testing, structural analysis of collagen fibrils by electron microscopy, and global analysis of gene expression by microarrays. RESULTS: We found that tendon samples from the older group had lower Young's modulus than the younger group (P = 0.015), whereas the stress to failure was similar in the two groups. We found no difference in the average diameter of collagen fibrils between the two groups. Microarray analysis identified 162 differentially expressed genes (fold change ≥ 1.5, P < 0.05), with overrepresentation of several biological processes, including regulation of adhesion, migration, inflammation, and differentiation (fold enrichment > 2.0, false discovery rate P < 0.05). CONCLUSION: The hamstring tendon from younger people has higher stiffness than tendon from older people, and the profile of gene expression in tendon varies with age. These differences may negatively affect the performance of the hamstring tendon in ACL reconstructions in younger people.

Molecular characterisation of osteoblasts from bone obtained from people of Polynesian and European ancestry undergoing joint replacement surgery.

Population studies in Aotearoa New Zealand found higher bone mineral density and lower rate of hip fracture in people of Polynesian ancestry compared to Europeans. We hypothesised that differences in osteoblast proliferation and differentiation contribute to the differences in bone properties between the two groups. Osteoblasts were cultured from bone samples obtained from 30 people of Polynesian ancestry and 25 Europeans who had joint replacement surgeries for osteoarthritis. The fraction of cells in S-phase was determined by flow cytometry, and gene expression was analysed by microarray and real-time PCR. We found no differences in the fraction of osteoblasts in S-phase between the groups. Global gene expression analysis identified 79 differentially expressed genes (fold change > 2, FDR P < 0.1). Analysis of selected genes by real-time PCR found higher expression of COL1A1 and KRT34 in Polynesians, whereas BGLAP, DKK1, NOV, CDH13, EFHD1 and EFNB2 were higher in Europeans (P ≤ 0.01). Osteoblasts from European donors had higher levels of late differentiation markers and genes encoding proteins that inhibit the Wnt signalling pathway. This variability may contribute to the differences in bone properties between people of Polynesian and European ancestry that had been determined in previous studies.

Infection prevention measures for orthopaedic departments during the COVID-2019 pandemic: a review of current evidence.

AIM: The coronavirus disease 2019 (COVID-19) pandemic presents significant challenges to healthcare systems globally. Orthopaedic surgeons are at risk of contracting COVID-19 due to their close contact with patients in both outpatient and theatre environments. The aim of this review was to perform a literature review, including articles of other coronaviruses, to formulate guidelines for orthopaedic healthcare staff. METHODS: A search of Medline, EMBASE, the Cochrane Library, World Health Organization (WHO), and Centers for Disease Control and Prevention (CDC) databases was performed encompassing a variety of terms including 'coronavirus', 'covid-19', 'orthopaedic', 'personal protective environment' and 'PPE'. Online database searches identified 354 articles. Articles were included if they studied any of the other coronaviruses or if the basic science could potentially applied to COVID-19 (i.e. use of an inactivated virus with a similar diameter to COVID-19). Two reviewers independently identified and screened articles based on the titles and abstracts. 274 were subsequently excluded, with 80 full-text articles retrieved and assessed for eligibility. Of these, 66 were excluded as they compared personal protection equipment to no personal protection equipment or referred to prevention measures in the context of bacterial infections. RESULTS: There is a paucity of high quality evidence surrounding COVID-19. This review collates evidence from previous coronavirus outbreaks to put forward recommendations for orthopaedic surgeons during the COVID-19 pandemic. The key findings have been summarized and interpreted for application to the orthopaedic operative setting. CONCLUSION: For COVID-19 positive patients, minimum suggested PPE includes N95 respirator, goggles, face shield, gown, double gloves, and surgical balaclava.Space suits not advised.Be trained in the correct technique of donning and doffing PPE.Use negative pressure theatres if available.Minimize aerosolization and its effects (smoke evacuation and no pulse lavage).Minimize further unnecessary patient-staff contact (dissolvable sutures, clear dressings, split casts).

The effect of age on the microarchitecture and profile of gene expression in femoral head and neck bone from patients with osteoarthritis.

Ageing of the skeleton is characterised by decreased bone mineral density, reduced strength, and increased risk of fracture. Although it is known that these changes are determined by the activities of bone cells through the processes of bone modelling and remodelling, details of the molecular mechanisms that underlie age-related changes in bone are still missing. Here, we analysed age-related changes in bone microarchitecture along with global gene expression in samples obtained from patients with osteoarthritis (OA). We hypothesised that changes would be evident in both microarchitecture and gene expression and aimed to identify novel molecular mechanisms that underlie ageing processes in bone. Samples of femoral head and neck were obtained from patients undergoing hip arthroplasty for OA, who were either ≤60 years or ≥70 years of age. Bone microarchitecture was analysed in cores of trabecular bone from the femoral head (17 from the younger group and 18 from the older), and cortical bone from the femoral neck (25 younger/22 older), using a Skyscan 1172 microCT scanner (Bruker). Gene expression was compared between the two age groups in 20 trabecular samples from each group, and 10 cortical samples from each group, using Clariom S Human microarrays (ThermoFisher Scientific). We found no significant changes between the two age groups in indices of trabecular or cortical bone microarchitecture. Gene expression analysis identified seven genes that had higher expression in the older group, including the transcription factor EGR1 and the glucose transporter SLC2A3 (GLUT3), and 21 differentially expressed genes in cortical bone samples (P<0.05, fold change>2). However, none of the comparisons of gene expression had false discovery rate-adjusted P<0.1. In contrast to our working hypothesis, we found only minor differences in gene expression and no differences in bone microarchitecture between the two age-groups. It is possible that pathological processes related to OA provide protection against age-related changes in bone. Our study suggests that in patients with OA, the bone properties measured here in femoral head and neck do not deteriorate significantly from the sixth to the eighth decade of life.

Human Cartilage Homogenates Influence the Crystallization of Monosodium Urate and Inflammatory Response to Monosodium Urate Crystals: A Potential Link Between Osteoarthritis and Gout.

OBJECTIVE: Monosodium urate (MSU) crystal deposition and gout flares frequently affect osteoarthritic joints. This study was undertaken to examine the effects of human cartilage homogenates on MSU crystallization and MSU crystal-induced inflammation. METHODS: Human cartilage homogenates were prepared from macroscopically healthy and macroscopically diseased knee joint samples. Crystallization assays were used to test the effects of cartilage homogenates or individual cartilage factors on MSU crystallization. Changes in urate solubility, crystal nucleation, crystal growth, and total crystal mass were determined. THP-1 cell assays were used to assess cytokine release following culture with MSU crystals grown in the presence or absence of cartilage homogenates or individual proteins. RESULTS: Addition of either 5% or 10% healthy cartilage homogenate increased the total mass of MSU crystals formed and resulted in formation of shorter MSU crystals compared to controls without cartilage homogenate. MSU crystal bows were observed in both the presence and absence of cartilage homogenate; however, bows formed in the presence of cartilage homogenates were significantly shorter than bows formed in their absence. There were no effect differences between macroscopically healthy and macroscopically diseased cartilage homogenates in all assessments. Addition of either type II collagen or albumin also led to the formation of shorter MSU crystals. In THP-1 cell assays, MSU crystals grown with healthy cartilage homogenate increased the release of interleukin-8, whereas MSU crystals grown with type II collagen or albumin had no effect on inflammatory cytokine release. CONCLUSION: In the presence of elevated urate levels, human cartilage homogenates increase MSU crystal formation and promote the formation of smaller crystals, which have greater inflammatory potential. These processes may contribute to the predilection of osteoarthritic joints to develop gout.

Bovine bone particulates containing bone anabolic factors as a potential xenogenic bone graft substitute.

BACKGROUND: Alternative grafts are needed to improve the healing of bone non-union. Here, we assessed a bovine bone product which retains the inorganic and organic components of bone, as an alternative bone graft. METHODS: Bovine bone matrix proteins (BBMPs) were isolated from bovine bone particulates (BBPs) and tested in vitro. Primary rat osteoblast viability, differentiation, and mineralisation were assessed with alamarBlue®, real-time PCR, and von Kossa staining assays, respectively. Osteoclast formation was assessed in primary murine bone marrow cultures with TRAP staining. Human osteoblast growth and differentiation in the presence of BBPs was evaluated in 3D collagen gels in vitro using alamarBlue® and real-time PCR, respectively. The efficacy of BBPs as an alternative bone graft was tested in a rat critical-size calvarial defect model, with histology scored at 4 and 12 weeks post-surgery. RESULTS: In vitro, the highest concentration of BBMPs increased mineral deposition five-fold compared to the untreated control group (P < 0.05); enhanced the expression of key osteoblast genes encoding for RUNX2, alkaline phosphatase, and osteocalcin (P < 0.05); and decreased osteoclast formation three-fold, compared to the untreated control group (P < 0.05). However, the BBPs had no effect on primary human osteoblasts in vitro, and in vivo, no difference was found in healing between the BBP-treated group and the untreated control group. CONCLUSIONS: Overall, despite the positive effects of the BBMPs on the cells of the bone, the bovine bone product as a whole did not enhance bone healing. Finding a way to harness the positive effect of these BBMPs would provide a clear benefit for healing bone non-union.

Local application of lactoferrin promotes bone regeneration in a rat critical-sized calvarial defect model as demonstrated by micro-CT and histological analysis.

Lactoferrin is a multifunctional glycoprotein with therapeutic potential for bone tissue engineering. The aim of this study was to assess the efficacy of local application of lactoferrin on bone regeneration. Five-millimetre critical-sized defects were created over the right parietal bone in 64 Sprague-Dawley rats. The rats were randomized into four groups: group 1 (n  = â€…20) had empty defects; group 2 (n  = â€…20) had defects grafted with collagen gels (3 mg/ml); group 3 (n  = â€…20) had defects grafted with collagen gels impregnated with bovine lactoferrin (10 µg/gel); and group 4 (n  = â€…4) had sham surgeries (skin and periosteal incisions only). The rats were sacrificed at 4 or 12 weeks post-operatively, and the calvaria were excised and evaluated with micro-CT (Skyscan 1172) followed by histology. The bone volume fraction (BV/TV) was higher in lactoferrin-treated animals at both timepoints, with groups 1, 2, 3 and 4 measuring 10.5  ± â€…1.1%, 8.6  ± â€…1.4%, 16.5  ± â€…0.6% and 24.27  ± â€…2.6%, respectively, at 4 weeks (P  < â€…0.05); and 12.2  ± â€…1.3%, 13.6  ± â€…1.5%, 21.9  ± â€…1.2% and 29.3  ± â€…0.8%, respectively, at 12 weeks (P  < â€…0.05). Histological analysis revealed that the newly formed bone within the calvarial defects of all groups was a mixture of woven and lamellar bone, with more bone in the group treated with lactoferrin at both timepoints. Our study demonstrated that local application of lactoferrin significantly increased bone regeneration in a rat critical-sized calvarial defect model. The profound effect of lactoferrin on bone regeneration has therapeutic potential to improve the poor clinical outcomes associated with bony non-union. LF In Vivo JTERM Authors Contributions. Copyright © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.

Human Spinal Bone Dust as a Potential Local Autograft: In Vitro Potent Anabolic Effect on Human Osteoblasts.

STUDY DESIGN: In vitro Study. OBJECTIVE: To evaluate the effect that factors released from human posterior spinal bone dust have on primary human osteoblast growth and maturation. SUMMARY OF BACKGROUND DATA: Bone dust, created during spinal fusion surgeries, has the potential to be used as an autologous bone graft by providing a source of viable autologous osteoblasts and mesenchymal stem cells with osteogenic potential. Till date, no information is available on whether bone dust also provides a source of anabolic factors with the potential to enhance osteoblast proliferation and maturation, which would enhance its therapeutic potential. METHODS: Bone dust was collected from consenting patients undergoing elective posterior spinal fusion surgeries, and primary human osteoblasts were cultured from patients undergoing elective hip or knee arthroplasty. Growth factors and cytokines released by bone dust were quantified using enzyme-linked immunosorbent assay. Primary human osteoblast proliferation and gene expression in response to bone dust were assessed using H-thymidine incorporation and real-time polymerase chain reaction, respectively. RESULTS: Human bone dust released anabolic cytokines (IL-1ß and IL-6) and growth factors (TGF-ß, VEGF, FGF-Basic, and PDGF-BB) in increasing concentrations over a 7-day period. In vitro, the anabolic factors released by bone dust increased osteoblast proliferation by 7-fold, compared with osteoblasts cultured alone. In addition, the factors released from bone dust up-regulated a number of osteoblastic genes integral to osteoblast differentiation, maturation, and angiogenesis. CONCLUSION: This study is the first to demonstrate that human posterior spinal bone dust released anabolic factors that potently enhance osteoblast proliferation and the expression of genes that favor bone healing and bone union. As bone dust is anabolic and its harvest is fast, simple, and safe to perform, spinal surgeons should be encouraged to 'recycle' bone dust and harness the regenerative potential of this free autologous bone graft. LEVEL OF EVIDENCE: N/A.

Induction of immune gene expression and inflammatory mediator release by commonly used surgical suture materials: an experimental in vitro study.

BACKGROUND: Surgeons have a range of materials to choose from to complete wound closure, yet surprisingly very little is still known about the body's immune response to the suture materials in current use. The growing literature of adverse suture material reactions provided the objective of this study, to use in vitro assays to quantify levels of inflammation produced by seven commonly used suture materials in surgical procedures. METHODS: Human monocyte/macrophage THP-1 cells were exposed to suture materials for 1, 3 and 5 days. Gene expression and protein secretion of six inflammatory cytokines and two cell surface markers were assessed using qPCR and ELISA respectively, with LPS exposure providing a positive control. Furthermore, a IL-1ß/IL-1RA marker ratio was assessed to determine the balance between pro-/anti-inflammatory expression. RESULTS: The findings from our in vitro study suggest that four commonly used suture materials cause upregulation of pro-inflammatory markers indicative of an early foreign body reaction, with no balance from anti-inflammatory markers. CONCLUSIONS: As prolonged early pro-inflammation is known to produce delayed wound healing responses, the knowledge produced from this study has potential to improve informed surgical decision making and patient safety. This work has the capability to reduce suture-related adverse immune reactions, and therefore positively affect patient outcomes.

The Efficacy of Local Autologous Bone Dust: A Systematic Review.

STUDY DESIGN: A systematic review of bone dust as an autologous bone graft to encourage osseous fusion. OBJECTIVE: To identify and review studies that report on the therapeutic potential of bone dust. The research question was structured as follows: populations-animal and human sources of bone dust harvested using burrs; interventions-autologous bone dust compared with other clinically utilized bone graft options; outcomes assessed-(1) in vitro cell viability, cell differentiation, and osteogenic potential and (2) clinical efficacy in the form of fusion rates as assessed using plain radiographs; study designs-in vitro, preclinical in vivo and clinical studies investigating the therapeutic potential of bone dust, harvested by burring, are included in this systematic review. SUMMARY OF BACKGROUND DATA: Little is known about the efficacy of bone dust, generated during burring of local bone in spine surgery, as a bone graft to encourage osseous union. METHODS: A systematic search was conducted in Medline, PubMed, OVID, Scopus, and Cochrane library. The following key words were used: bone dust, bone burring, bone paste, bone pate. RESULTS: A total of 285 studies were reviewed. Fourteen articles were identified as relevant for inclusion in this systematic review. Current evidence suggests that bone dust retains osteogenic properties, but limited information is available regarding the osteoinductive potential of bone dust. CONCLUSION: Bone dust represents a free source of autologous bone, which can be easily collected during the time of surgery and used as an augment to aid osseous fusion. Further research is required to evaluate the osteoinductive potential of bone dust. The retained growth factors in bone dust may potentially induce local osteoprogenitor cells to proliferate and mineralize to form new bone.

Correlation of Pirani and Dimeglio scores with number of Ponseti casts required for clubfoot correction.

BACKGROUND: A number of grading systems for severity of clubfoot have been reported in the literature, but none are universally accepted. The aim of this study was to find the correlation between 2 of the most widely utilized classification systems (the Pirani score and the Dimeglio score) with number of Ponseti casts required to achieve initial clubfeet correction. METHODS: A retrospective study of prospectively collected data was performed. All clubfeet assessed at our dedicated clubfoot clinic from January 2007 to December 2011 were included. Clubfoot severity was assessed using both the Pirani score and the Dimeglio score. The total number of casts was calculated from the first cast to the time of initiation of the foot abduction orthosis. RESULTS: The mean number of Ponseti casts required to achieve initial correction was 5.8 (range, 2 to 10 casts). A low correlation (rs 0.21) was identified when the total Dimeglio score was compared with the number of casts. No correlation (rs 0.12) was identified between the Pirani score and the number of casts. CONCLUSIONS: The Dimeglio and Pirani scores remain the most widely accepted clubfoot severity grading systems. However, their prognostic value remains questionable, at least in the early treatment stages. LEVEL OF EVIDENCE: Prognostic study level II.

Review of 100 consecutive microvascular free flaps.

AIM: To analyse the outcome of microvascular free flap reconstructions in Middlemore Hospital (South Auckland, New Zealand). METHOD: 100 consecutive free flap reconstructions from January 2004 to April 2010 were identified from the Middlemore Hospital Theatre Coding List. Basic patient demographics and indication for surgery along with free flap types were recorded and outcomes were analysed. RESULTS: The free flap success rate was 96%. There were 21 short term complications without any perioperative mortality. The most common complication was flap infection (7/21) followed by vascular thrombosis (6/21 venous and 1/21 arterial). Other complications included partial ischaemic flap (3/21), haematoma (2/21), venous congestion (1/21) and partial wound dehiscence (1/21). Fourteen flaps needed salvage procedures in the operating theatre including eight cases for re-anastomosis of vessels. The overall successful salvage rate was 71% resulting in four failures. The successful salvage rate following re-anastomosis of vessels was 63%. CONCLUSION: Overall success and salvage rates for free flap reconstructions at our plastics and reconstruction centre are comparable to that of international literature. Diligent postoperative monitoring and early return to theatre for re-exploration is the key to ensuring maximal free flap success.

Seeing patients first: creating an opportunity for practice nurse care?

INTRODUCTION: Practice nurses see patients in both a planned (i.e., scheduled appointment) and an unplanned (i.e., opportunistic) manner. This study aimed to investigate how often and why New Zealand practice nurses see patients prior to the general practitioner and whether they organise their care to support unplanned, opportunistic activity. METHOD: National postal survey from a random sample of 500 general practices, requesting a response from one nurse per practice. Semi-structured telephone interviews with a purposeful sample of respondents. FINDINGS: Responses came from 225 nurses (51% of practices confirmed to be eligible). Nearly all (92%) said their work role was the same as that of others in their practice. Only 13% of nurses routinely saw patients prior to the doctor, while 24% would choose to do so it they could, and 65% thought it important. Positive and negative aspects of seeing patients first are presented. Constraints included time, their role assisting practice workflow and perceptions of patient expectations. Few organised their work to create opportunities for lifestyle interventions. CONCLUSION: The current working environment of practice nurses in New Zealand does not readily support them routinely seeing patients before the general practitioner. We suggest this is a lost opportunity for patient-centred preventive care.