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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 115 - 115
2 Jan 2024
Akbar M Crowe L Woolcock K Cole J McInnes I Millar N
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Dupuytren's disease (DD) is a fibroproliferative soft tissue disease affecting the palmar fascia of the hand causing permanent and irreversible flexion contracture. Aberrant fibrosis is likely to manifest through a combination of extrinsic, intrinsic, and environmental factors, including genetics and epigenetics. However, the role of epigenetics in soft tissue fibrosis in diseases such as DD is not well established. Therefore, we conducted a comprehensive multi-omic study investigating the epigenetic profiles that influence gene expression in DD pathology. Using control (patients undergoing carpal tunnel release) and diseased fibroblasts (patients undergoing Dupuytren's fasciectomy), we conducted ATAC-seq to assess differential chromatin accessibility between control and diseased fibroblasts. Additionally, ChIP-seq mapped common histone modifications (histone H4; H3K4me3, H3K9me3, H3K27me3, H4K16Ac, H4K20Me3) associated with fibrosis. Furthermore, we extracted RNA from control and DD tissue and performed bulk RNA-seq.

ATAC-seq analysis identified 2470 accessible genomic loci significantly more accessible in diseased fibroblasts compared to control. Comparison between diseased and control cells identified numerous significantly different peaks in histone modifications (H4K20me3, H3K27me3, H3K9me3) associated with gene repression in control cells but not in diseased cells. Pathway analysis demonstrated a substantial overlap in genes being de-repressed across these histone modifications (Figure 1). Both, ATAC-seq and ChIP-seq analysis indicated pathways such as cell adhesion, differentiation, and extracellular matrix organisation were dysregulated as a result of epigenetic changes. Moreover, de novo motif enrichment analysis identified transcription factors that possibly contributed to the differential gene expression between control and diseased tissue, including HIC1, NFATC1 and TEAD2. RNA-seq analysis found that these transcription factors were upregulated in DD tissue compared to control tissue.

The current epigenetic study provides insights into the aberrant fibrotic processes associated with soft tissue diseases such as DD and indicates that epigenetic-targeted therapies may be an interesting viable treatment option in future.

For any figures or tables, please contact the authors directly.


Bone & Joint Research
Vol. 4, Issue 3 | Pages 45 - 49
1 Mar 2015
Thompson MJ Ross J Domson G Foster W

Objectives. The clinical utility of routine cross sectional imaging of the abdomen and pelvis in the screening and surveillance of patients with primary soft-tissue sarcoma of the extremities for metastatic disease is controversial, based on its questionable yield paired with concerns regarding the risks of radiation exposure, cost, and morbidity resulting from false positive findings. Methods. Through retrospective review of 140 patients of all ages (mean 53 years; 2 to 88) diagnosed with soft-tissue sarcoma of the extremity with a mean follow-up of 33 months (0 to 291), we sought to determine the overall incidence of isolated abdominopelvic metastases, their temporal relationship to chest involvement, the rate of false positives, and to identify disparate rates of metastases based on sarcoma subtype. Results. A total of four patients (2.9%) exhibited isolated abdominopelvic metastatic disease during the surveillance period. In all cases of concomitant chest and abdominopelvic disease, chest involvement preceded abominopelvic involvement. There was a significant false positive rate requiring invasive workup. Conclusions. In the setting of a relative paucity of evidence concerning a rare disease process and in difference to recently published investigations, we add a clinical cohort not supportive of routine cross sectional imaging of the abdomen and pelvis. Cite this article: Bone Joint Res 2015;4:45–9


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_2 | Pages 130 - 130
2 Jan 2024
Dvorak N
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In-vitro models of disease are valuable tools for studying disease and analysing response to therapeutics. Recently, advances in patient-derived organoid (PDO) models have been shown to faithfully recapitulate structure, function, and therapeutic response for a wide range of tissues. Frozen shoulder is a rare example of a chronic inflammatory fibrotic disease which is self-limiting, unlike many other soft tissue fibrotic disorders. As no in-vitro 3D models or in-vivo animal models exist for frozen shoulder, establishing an organoid model which recapitulates core diseases features may give insight into fibrosis resolution. Consequently, using biocompatible hydrogels, primary capsular fibroblasts, monocyte-derived macrophages and HUVEC cells, we generated stable PDO cultures which exhibited key disease phenotypes, including vascularization, increased stiffness, and an expanded lining layer over 21 days of culture. Through further investigation of cell-matrix and cell-cell interactions in the organoid model, we intend to unpack the differences between resolving and non-resolving fibrotic disease and uncover clinically relevant therapeutic targets for fibrosis.


The Journal of Bone & Joint Surgery British Volume
Vol. 85-B, Issue 1 | Pages 126 - 132
1 Jan 2003
Mittlmeier T Vollmar B Menger MD Schewior L Raschke M Schaser K

A major pathway of closed soft-tissue injury is failure of microvascular perfusion combined with a persistently enhanced inflammatory response. We therefore tested the hypothesis that hypertonic hydroxyethyl starch (HS/HES) effectively restores microcirculation and reduces leukocyte adherence after closed soft-tissue injury. We induced closed soft-tissue injury in the hindlimbs of 14 male isoflurane-anaesthetised rats. Seven traumatised animals received 7.5% sodium chloride-6% HS/HES and seven isovolaemic 0.9% saline (NS). Six non-injured animals did not receive any additional fluid and acted as a control group. The microcirculation of the extensor digitorum longus muscle (EDL) was quantitatively analysed two hours after trauma using intravital microscopy and laser Doppler flowmetry, i.e. erythrocyte flux. Oedema was assessed by the wet-to-dry-weight ratio of the EDL. In NS-treated animals closed soft-tissue injury resulted in massive reduction of functional capillary density (FCD) and a marked increase in microvascular permeability and leukocyte-endothelial cell interaction as compared with the control group. By contrast, HS/HES was effective in restoring the FCD to 94% of values found in the control group. In addition, leukocyte rolling decreased almost to control levels and leukocyte adherence was found to be reduced by ~50%. Erythrocyte flux in NS-treated animals decreased to 90 ± 8% (mean . sem. ), whereas values in the HS/HES group significantly increased to 137 ± 3% compared with the baseline flux. Oedema in the HS/HES group (1.06 ± 0.02) was significantly decreased compared with the NS-group (1.12 ± 0.01). HS/HES effectively restores nutritive perfusion, decreases leukocyte adherence, improves endothelial integrity and attenuates oedema, thereby restricting tissue damage evolving secondary to closed soft-tissue injury. It appears to be an effective intervention, supporting nutritional blood flow by reducing trauma-induced microvascular dysfunction


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 26 - 26
1 Mar 2021
Malik S Hart D Parashin S Malik S McRae S MacDonald P
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Abstract

Objectives

To evaluate mechanical properties of three suture-tendon constructs, the Krackow stitch (KS), the modified Prusik knot (PK) and the Locking SpeedWhip (LSW), using human cadaveric quadriceps grafts (QT).

Methods

Thirty QT grafts were obtained from human cadaver specimens and an equal number of tendon-suture constructs were prepared for three stitches: KS, PK and LSW. The constructs were mounted in a materials testing machine (ElectroPuls E10000, Instron, Norwood, MA) and subject to tensile loading based on an established protocol. Load and displacement data for each tendon-suture construct were recorded.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 49 - 49
1 Dec 2020
Makelov B Gueorguiev B Apivatthakakul T
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Introduction

Being challenging, multifragmentary proximal tibial fractures in patients with severe soft tissue injuries and/or short stature can be treated using externalized locked plating. A recent finite element study, investigating the fixation stability of plated unstable tibial fractures with 2-mm, 22-mm and 32-mm plate elevation under partial and full weight-bearing, reported that from a virtual biomechanical point of view, externalized plating seems to provide appropriate relative stability for secondary bone healing under partial weight-bearing during the early postoperative phase. The aim of the current study was to evaluate the clinical outcomes of using a LISS plate as a definitive external fixator for the treatment of multifragmentary proximal tibial fractures.

Methods

Following appropriate indirect reduction, externalized locked plating was performed and followed up in 12 patients with multifragmentary proximal tibial fractures with simple intraarticular involvement and injured soft tissue envelope.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_15 | Pages 5 - 5
1 Nov 2018
Huegel J Boorman-Padgett J Nuss C Minnig M Tucker J Cirone J Morris T Choi D Kuntz A Waldorff E Zhang N Ryaby J Soslowsky L
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PEMF is currently approved by the FDA for adjunctive treatment of lumbar/cervical spine fusion and for treatment of long-bone non-unions. Soft tissues are a potential new therapeutic application for PEMF due to pre-clinical studies showing a reduction of inflammatory markers following PEMF exposure. The aim was therefore to investigate the structural/functional effects of PEMFs on tendon-to-bone and tendon-to-tendon healing in a rotator-cuff (RC) and Achilles tendon (AT) repair model, respectively. RC study: Adult male rats (n=280), underwent bi-lateral supraspinatus tendon transections with immediate repair followed by cage activity until sacrifice (4, 8, and 16 weeks). Non-controls received PEMF for 1, 3, or 6 hours daily. AT study: Male rats underwent acute, complete transection and repair of the Achilles tendon (FULL, n=144) or full thickness, partial width injury (PART, n=160) followed by immobilization for 1 week. Sacrifice was at 1, 3, and 6 weeks. Outcome measures included passive joint mechanics, gait analysis, biomechanical assessments, histological analysis of the repair site and mCT (humerus) assessment (FULL only). RC study: Significant increases in modulus, stiffness, bone mineral content and improved collagen organization was observed for the PEMF groups. No differences in joint mechanics and ambulation were observed. AT study: A decrease in stiffness and limb-loading rate was observed for the PEMF groups for the FULL groups, whereas an increase in stiffness with no change in range-of-motion was seen for the PART groups. The combined studies show that PEMF can be effective for soft tissue repair but is dependent on the location of application.


To describe clinical situations for use of modified VAC in POC based on: diagnosis, comorbidities, BMI, wound size in cm, days following trauma when VAC was first applied, total duration of uninterrupted use, frequency of change, settings, bacterial growth, outcomes

To report the outcomes of mVAC use in POC within 6 months to help improve and standardize its application in the institution

This study involves data gathering from inpatients handled by orthopedic surgeons in training and subspecialty rotations in POC. The data collected are highly dependent on the doctors-in-charge's complete charting, thorough reporting and accurate documentation. Modified Vacuum Assisted Closure (mVAC) is used frequently in this study and is defined as a form of revised, adapted and reformed use of VAC based on available materials in the involved institution. The materials that are included are, but not limited to the following: sterile Uratex™ blue foam, nasogastric or suction tubing, phlegm suction machine, Bactigras™ and Opsite™ or Ioban™.

A total of 58 patients were included in the study. The average age of the population was 35 and are predominantly male. The most common mechanism of injury was motorcycle accident and 37 of the patients were diagnosed with an open fracture of the lower extremity with open tibia fractures (22) being the most common. Average wound area measured was 24.12 cm3. All patients yield a bacteria growth with e. coli being the most frequent. Average during of uninterrupted use was 39 days. Of the 58 included in the study, 8 patients underwent STSG, 2 had a flap coverage surgery, 4 patients eventually underwent amputation and 33 with complete resolution of soft tissue defect after conversion to biologic dressing post-mVAC. The rest of the population were still ongoing mVAC at the end of the study.

mVAC is an alternative temporary medium for soft tissue coverage for cases with or without concomitant fractures. mVAC promotes removal of exudate from the wound, supports wound apposition and granulation bed proliferation. Usage mVAC helps prepare for skin coverage procedure and on some cases leads to full resolution of defect.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_2 | Pages 29 - 29
1 Jan 2019
Yao J Mengoni M Williams S Jones A
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Acetabular tissue damage is implicated in osteoarthritis (OA) and investigation of in situ acetabular soft tissues behaviour will improve understanding of tissue properties and interconnections. The study aim was to visualise acetabular soft tissues under load and to quantify displacements using computed tomography (CT) scans (XtremeCT, Scano Medical).

A CT scan (resolution 82 μm) was performed on the disarticulated, unloaded porcine acetabulum. The femoral head was soaked in Sodium Iodide (NaI) solution and cling film wrapped to prevent transfer to the acetabular side. The joint was realigned, compressed using cable ties and re-scanned. The two images were down-sampled to 0.3 mm. Acetabular bone and soft tissues were segmented. Bony features were used to register the two background images, using Simpleware ScanIP 7.0 (Synopsys), to the same position and orientation (volume difference < 5%). Acetabular soft tissues displacements were measured by tracking the same points at the tissue edges on the two acetabular masks, along with difference in bone position as an additional error assessment.

The use of radiopaque solution provided a clear contrast allowing separation of the femoral and acetabular soft tissues in the loaded image. The image registration process resulted in a difference in bone position in the areas of interest equivalent to image resolution (0.3 mm, a mean of 3 repeats by same user). A labral tip displacement of 1.7 mm and a cartilage thickness change from 1.5 mm unloaded to 0.9 mm loaded, were recorded.

The combination of contrast enhancement, registration and focused local measurement was precise enough to reduce bone alignment error to that of image resolution and reveal local soft tissue displacements. These measurement methods can be used to develop models of soft tissues properties and behaviour, and therapy for hip tissue damage at early stage may be reviewed and optimised.


Abstract

Objectives

Initial performance of sutured quadriceps tendon (QT) ACL graft constructs is not well studied in human tissue and the results of animal tissue testing may not extend to the human model. Two common methods of preserving human tissue are to freeze the specimens immediately after death or embalm with formalin solution. The purpose of this study is to compare elongations and loads in biomechanical testing of fresh-frozen to that of embalmed quadriceps tendon-suture constructs.

Methods

Twenty QT grafts were harvested from human cadaver specimens, 10 fresh-frozen and 10 embalmed. The grafts were prepared with the modified Prusik knot using a No.2 FiberWire (Arthrex, Naples, FL), mounted in a materials testing machine (ElectroPuls E10000, Instron, Norwood, MA) and subjected to tensile loading based on an established protocol. Each tendon was preconditioned with 3 cycles of 0–100N at 1Hz followed by a constant load of 50N for 1 minute and 200 cycles from 50–200N at 1Hz and then loaded to failure at a displacement rate of 20mm/min. Load and displacement data for each tendon-suture construct was recorded.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 56 - 56
1 Mar 2021
Malik S Hart D Parashin S McRae S Peeler J MacDonald P
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Abstract

Objectives

ACL graft-suture fixation can be constructed with needle or needleless techniques. Needleless techniques have advantages of decreased injury, preparation time and cost. The Nice Knot (NK) is common among upper extremity procedures; however, its efficacy in ACL reconstruction relative to other needleless methods is not well known. The purpose of this study was to biomechanically compare quadriceps tendon (QT) grafts prepared with the NK versus the modified Prusik Knot (PK).

Methods

Twenty QT grafts were harvested from 10 embalmed human cadaver specimens. 10 were prepared with the PK and 10 with the NK using a No.2 FiberWire (Arthrex, Naples, FL). The prepared grafts were then mounted in a materials testing machine (ElectroPuls E10000, Instron, Norwood, MA) and subjected to tensile loading based on an established protocol. Each tendon-suture specimen was preconditioned with 3 cycles of 0–100N at 1Hz followed by a constant load of 50N for 1 minute and cyclic loading of 200 cycles from 50–200N at 1Hz and then loaded to failure at a displacement rate of 20mm/min. Load and displacement data for each tendon-suture construct was recorded by the testing machine.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_14 | Pages 24 - 24
1 Nov 2018
Kepple T Bradley K Loan P Tashman S Anderst W De Asha A
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Conventional marker based optical motion capture (mocap) methods for estimating the position and orientation (pose) of anatomical segments use assumptions that anatomical segments are rigid bodies and the position of tracking markers is invariant relative to bones. Soft tissue artefact (STA) is the error in pose estimation due to markers secured to soft tissue that moves relative to bones. STA is a major source of pose estimation error and is most prevalent when markers are placed over joints. Mocap and bi-plane videoradiography data were recorded synchronously while three individuals walked on a treadmill. For all three, pose of the thigh and shank, and movement of markers relative to the bones, were determined from the videoradiography data (DSX, C-Motion). Independently, pose of thighs and shanks was estimated using mocap data (Visual3D, C-Motion). Our measures of error in the mocap pose estimation were the relative thigh and shank translations. X-ray data from two subjects were used to generate a regression model for the antero/posterior movement of the lateral knee marker against internal/external hip rotation. The mocap translation errors of the third subject, attributed to STA of the knee marker, were 15.6mm and 32.0mm respectively. The pose of the third subject was then estimated using a probabilistic algorithm incorporating our regression model. Mocap translation errors were reduced to 10.6mm (thigh) and 4.4mm (shank). The results from these data suggest that errors in pose estimation due to STA may possibly be reduced via the application of algorithms based on probabilistic inference to mocap data.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_2 | Pages 7 - 7
1 Jan 2019
Owston H Moisley K Tronci G Giannoudis P Russell S Jones E
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The current ‘gold’ standard surgical intervention for critical size bone defect repair involves autologous bone grafting, that risks inadequate graft containment and soft tissue invasion. Here, a new regenerative strategy was explored, that uses a barrier membrane to contain bone graft. The membrane is designed to prevent soft tissue ingrowth, whilst supporting periosteal regrowth, an important component to bone regeneration. This study shows the development of a collagen-based barrier membrane supportive of periosteal-derived mesenchymal stem cell (P-MSC) growth.

P-MSC-homing barrier membranes were successfully obtained with nonaligned fibres, via free-surface electrospinning using type I collagen and poly(E-caprolactone) in 1,1,1,3,3,3-Hexafluoro-2-propanol. Introduction of collagen in the electrospinning mixture was correlated with decreased mean fibre diameter (d: 319 nm) and pore size (p: 0.2–0.6 μm), with respect to collagen-free membrane controls (d: 372 nm; p: 1–2 μm). Consequently, as the average MSC diameter is 20 μm, this provides convincing evidence of the creation of a MSC containment membrane.

SEM-EDX confirmed Nitrogen and therefore collagen fibre localisation. Quantification of collagen content, using Picro Sirius Red dye, showed a 50% reduction after 24 hours (PBS, 37 °C), followed by a drop to 25% at week 3. The collagen-based membrane has a significantly higher elastic modulus compared to collagen-free control membranes. P-MSCs attached and proliferated when grown onto collagen-based membranes, imaged using confocal microscopy over 3 weeks. A modified transwell cell migration assay was developed, using MINUSHEET® tissue carriers to assess barrier functionality. In line with the matrix architecture, the collagen-based membrane proved to prevent cell migration (via confocal microscopy) in comparison to the migration facilitating positive control.

The aforementioned results obtained at molecular, cellular and macroscopic scales, highlight the applicability of this barrier membrane in a new ‘hybrid graft’ regenerative approach for the surgical treatment of critical size bone defects.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 62 - 62
1 Apr 2018
Soufi M Haque S Jayaraman S Faris B Shoaib A
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Aim

To determine if systemic toxicity occurs after the use of antibiotic loaded calcium sulphate in the treatment (1) of bone and soft tissue infection.

Although antibiotic loaded calcium sulphate is increasingly used for the local treatment of bone and soft tissue infection, there is little data to demonstrate that systemic levels generated by local release of antibiotics are safe. For this reason, we routinely assay systemic levels of antibiotics.

Methods

Patients with osteomyelitis or soft tissue infection underwent surgical debridement and lavage of the infected tissue in routine fashion. Patients with osteomyelitis were graded with the Cierny-Mader classification. Bone cavities and soft tissue dead spaces were packed with antibiotic loaded calcium sulphate (10–40 cc) loaded with Vancomycin (1–4 g) and Gentamicin (240–960 mg). The wounds were closed over the antibiotic loaded calcium sulphate.

Patients underwent serial assays of Vancomycin and Gentamicin levels on the day of surgery and the first two post-operative days. Renal function was also measured.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 3 | Pages 411 - 415
1 Mar 2006
Challis MJ Gaston P Wilson K Jull GA Crawford R

The aim of this randomised, controlled in vivo study in an ovine model was to investigate the effect of cylic pneumatic pressure on fracture healing. We performed a transverse osteotomy of the right radius in 37 sheep. They were randomised to a control group or a treatment group where they received cyclic loading of the osteotomy by the application of a pressure cuff around the muscles of the proximal forelimb. Sheep from both groups were killed at four or six weeks. Radiography, ultrasonography, biomechanical testing and histomorphometry were used to assess the differences between the groups. The area of periosteal callus, peak torsional strength, fracture stiffness, energy absorbed over the first 10° of torsion and histomorphometric analysis all showed that the osteotomies treated with the cyclic pneumatic pressure at four weeks were not significantly different from the control osteotomies at six weeks.


Recent National Institute for Health and Care Excellence (NICE) guidance has advised against the continued use of the Thompson implant when performing hip hemiarthroplasty and recommended surgeons consider using the anterolateral surgical approach over a posterior approach.

Our objective was to review outcomes from a consecutive series of Thompson hip hemiarthroplasty procedures performed in our unit and to identify any factors predicting the risk of complications.

807 Thompson hip hemiarthroplasty cases performed between April 2008 and November 2013 were reviewed. 721 (89.3%) were cemented and 86 (10.7%) uncemented. 575 (71.3%) were performed in female patients. The anterolateral approach was performed in 753 (93.3%) and the posterior approach with enhanced soft tissue repair in 54 (6.7%).

Overall, there were 23 dislocations (2.9%). Dislocation following the posterior approach occurred in 13.0% (7 of 54) in comparison to 2.1% (16 of 753) with the anterolateral approach (odds ratio (OR) 8.5 (95% CI 2.8 to 26.3) p < 0.001). Surgeon grade and patient history of cognitive impairment did not have a significant impact on dislocation rate.

Patients were discharged home in 459 cases (56.9%), to a care home or other hospital in 273 cases (33.8%). 51.8% (338 of 653) returned home within 30 days. 75 died during their admission (9.3%). 30-day mortality was 7.1% and 1-year mortality was 16.6%.

Intraoperative fracture occurred in 15 cases (1.9%) of which 14 were cemented. Superficial or deep infection occurred in 33 cases (4.1%).

We recommend against the continued use of the posterior approach in hip hemiarthroplasty, as enhanced soft tissue repair did not reduce dislocation rates to an acceptable level. Our findings, however, demonstrate satisfactory results for patients treated with the Thompson hip hemiarthroplasty performed through an anterolateral approach. We suggest that the continued use of the Thompson implant in a carefully selected patient cohort is justifiable.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 62 - 62
11 Apr 2023
Preutenborbeck M Wright P Loughran G Bishop N
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Orthopaedic impaction-instruments are used to drive implants into the bone of the patient. Pre-clinical experimental testing protocols and computer models of those are used to assess robustness and functional efficiency of such instruments. This generally involves impaction of the instrument mounted on a substrate that should represent the mechanics of the patient. In this study, the effects of the substrate on stressing of the impaction-instruments were investigated using dynamic finite element analysis. Model results were compared with experimental data from lab protocols, which have been derived to recreate the mechanics of cadaveric implantations, which represent clinical conditions. FEA models of selected experimental protocols were created in which a simplified instrument was impacted on substrates with varying material properties and boundary conditions. After impaction, the instrument settled into a modal vibration which then decayed over time. The resulting axial strain data from the computational model was compared to strain-gauge data collected from experimental measurements. Strain signal amplitude, frequency and decay were compared. The damping-ratio was derived from the decay of the strain signal. The computational model slightly over-predicted the initial experimental strain amplitudes in all cases, but the frequency of the cyclic strain signals matched. However, the model underestimated the experimentally measured rate of signal decay. Inclusion of implant seating and soft-tissue conditions had little effect on decay. Clinical failures of impaction-instruments may be related to multiple fatigue cycles for each impaction and should be modelled accurately to allow failure prediction. Any soft substrate results in an impedance mismatch at the instrument interface, which reflects the pressure wave and causes vibration with a frequency related to the speed-of-sound in the instrument, and its geometry. While this could be accurately modelled computationally, signal decay was underestimated. Further experimental quantification of energy losses will be important to understand vibration decay


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 89 - 89
17 Apr 2023
Alzahrani S Aljuaid M Bazaid Z Shurbaji S
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A Morel-Lavallee lesion (MLL) is a benign cystic lesion that occurs due to injury to the soft-tissue envelope's perforating vascular and lymphatic systems, resulting in a distinctive hemolymphatic fluid accumulation between the tissue layers. The MLL has the potential to make a significant impact on the treatment of orthopaedic injuries. A 79-year-old male patient community ambulatory with assisting aid (cane) known case of Diabetes mellitus, hypertension, bronchial asthma and ischemic heart disease. He was brought to the Emergency, complaining of right hip discomfort and burning sensation for the last 5 days with no history of recent trauma at all. Patient had history of right trochanteric femur fracture 3 years ago, treated with DHS in a privet service. Clinical and Radiological assessment showed that the patient mostly has acute MLL due to lag screw cut out. We offered the patient the surgical intervention, but he refused despite explaining the risks of complications if not treated and preferred to receive the conservative treatment. Compression therapy management explained to him including biker's shorts (instructed to be worn full-time a day) and regular follow up in clinic. Symptom's improvement was reported by the patient in the subsequent visits. In the polytrauma patient, a delayed diagnosis of these lesions is conceivable due to the presence of more visible injuries. It's located over the greater trochanter more commonly, but sometimes in other areas such as the lower lumbar region, the thigh, or the calf. Incorrect or delayed diagnosis and care can have unfavorable outcomes such as infection, pseudocyst development, and cosmetologically deformity. Magnetic resonance imaging (MRI) and ultrasound will aid in MLL diagnosis. However, the effectiveness of MLL therapy remains debatable. We strongly believe that the MLL caused due to tangential shear forces applied to the soft tissue leads to accumulation of the blood and/or lymph between the subcutaneous and overlying fascia and it often misdiagnosed due to other distracting injuries. Nontheless, in our case we reported MLL occur due to internal pressure on the fascia caused by cut out of DHS lag screw


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 60 - 60
11 Apr 2023
Chalak A Kale S Mehra S Gunjotikar A Singh S Sawant R
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Osteomyelitis is an inflammatory condition accompanied by the destruction of bone and caused by an infecting microorganism. Open contaminated fractures can lead to the development of osteomyelitis of the fractured bone in 3-25% of cases, depending on fracture type, degree of soft-tissue injury, degree of microbial contamination, and whether systemic and/or local antimicrobial therapies have been administered. Untreated, infection will ultimately lead to non-union, chronic osteomyelitis, or amputation. We report a case series of 10 patients that presented with post-operative infected non-union of the distal femur with or without prior surgery. The cases were performed at Padmashree Dr. D. Y. Patil Hospital, Nerul, Navi Mumbai, India. All the patients’ consents were taken for the study which was carried out in accordance with the Helsinki Declaration. The methodology involved patients undergoing a two-stage procedure in case of no prior implant or a three-stage procedure in case of a previous implant. Firstly, debridement and implant removal were done. The second was a definitive procedure in form of knee arthrodesis with ring fixator and finally followed by limb lengthening surgery. Arthrodesis was planned in view of infection, non-union, severe arthritic, subluxated knee, stiff knee, non-salvage knee joint, and financial constraints. After all the patients demonstrated wound healing in 3 months along with good radiographic osteogenesis at the knee arthrodesis site, limb lengthening surgeries by tibial osteotomy were done to overcome the limb length discrepancy. Distraction was started and followed up for 5 months. All 10 patients showed results with sound knee arthrodesis and good osteogenesis at the osteotomy site followed by achieving the limb length just 1-inch short from the normal side to achieve ground clearance while walking. Our case series is unique and distinctive as it shows that when patients with infected nonunion of distal femur come with the stiff and non-salvage knee with severe arthritic changes and financial constraints, we should consider knee arthrodesis with Ilizarov ring fixator followed by limb lengthening surgery


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 97 - 97
11 Apr 2023
Milakovic L Dandois F Fehervary H Scheys L
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This study aims to create a novel computational workflow for frontal plane laxity evaluation which combines a rigid body knee joint model with a non-linear implicit finite-element model wherein collateral ligaments are anisotropically modelled using subject-specific, experimentally calibrated Holzpfel-Gasser-Ogden (HGO) models. The framework was developed based on CT and MRI data of three cadaveric post-TKA knees. Bones were segmented from CT-scans and modelled as rigid bodies in a multibody dynamics simulation software (MSC Adams/view, MSC Software, USA). Medial collateral and lateral collateral ligaments were segmented based on MRI-scans and are modelled as finite elements using the HGO model in Abaqus (Simulia, USA). All specimens were submitted varus/valgus loading (0-10Nm) while being rigidly fixed on a testing bench to prevent knee flexion. In subsequent computer simulations of the experimental testing, rigid bodies kinematics and the associated soft-tissue force response were computed at each time step. Ligament properties were optimised using a gradient descent approach by minimising the error between the experimental and simulation-based kinematic response to the applied varus/valgus loads. For comparison, a second model was defined wherein collateral ligaments were modelled as nonlinear no-compression spring elements using the Blankevoort formulation. Models with subject-specific, experimentally calibrated HGO representations of the collateral ligaments demonstrated smaller root mean square errors in terms of kinematics (0.7900° +/− 0.4081°) than models integrating a Blankevoort representation (1.4704° +/− 0.8007°). A novel computational workflow integrating subject-specific, experimentally calibrated HGO predicted post-TKA frontal-plane knee joint laxity with clinically applicable accuracy. Generally, errors in terms of tibial rotation were higher and might be further reduced by increasing the interaction nodes between the rigid body model and the finite element software. Future work should investigate the accuracy of resulting models for simulating unseen activities of daily living