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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 48 - 48
2 Jan 2024
Emmanuel A
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Non-linear methods in statistical shape analysis have become increasingly important in orthopedic research as they allow for more accurate and robust analysis of complex shape data such as articulated joints, bony defects and cartilage loss. These methods involve the use of non-linear transformations to describe shapes, rather than the traditional linear approaches, and have been shown to improve the precision and sensitivity of shape analysis in a variety of applications. In orthopedic research, non-linear methods have been used to study a range of topics, including the analysis of bone shape and structure in relation to osteoarthritis, the assessment of joint deformities and their impact on joint function, and the prediction of patient outcomes following surgical interventions. Overall, the use of non-linear methods in statistical shape analysis has the potential to advance our understanding of the relationship between shape and function in the musculoskeletal system and improve the diagnosis and treatment of orthopedic conditions.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 130 - 130
11 Apr 2023
Biddle M Wilson V Miller N Phillips S
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Our aim was to ascertain if K-wire configuration had any influence on the infection and complication rate for base of 4th and 5th metacarpal fractures. We hypothesised that in individuals whose wires crossed the 4th and 5th carpometacarpal joint (CMCJ), the rate of complications and infection would be higher. Data was retrospectively analysed from a single centre. 106 consecutive patients with a base of 5th (with or without an associated 4th metacarpal fracture) were analysed between October 2016 and May 2021. Patients were split into two groups for comparison; those who did not have K-wires crossing the CMCJ's and those in whose fixation had wires crossing the joints. Confounding factors were accounted for and Statistical analysis was performed using SPSS version 20 software. Of 106 patients, 60 (56.6%) patients did have K-wires crossing the CMCJ. Wire size ranged from 1.2-2.0 with 65 individuals (65.7%) having size 1.6 wires inserted. The majority of patients, 66 (62.9%) underwent fixation with two wires (range 1-4). The majority of infected cases (88.9%) were in patients who had k-wires crossing the CMCJ, this trended towards clinical significance (p=0.09). Infection was associated with delay to theatre (p=0.002) and longer operative time (p=0.002). In patients with a base of 4th and 5th metacarpal fractures, we have demonstrated an increased risk of post-operative infection with a K-wire configuration that crosses the CMCJ. Biomechanical studies would be of use in determining the exact amount of movement across the CMCJ, with the different K-wire configuration in common use, and this will be part of a follow-up study


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 93 - 93
4 Apr 2023
Mehta S Goel A Mahajan U Kumar P
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C. Difficile infections in elderly patients with hip fractures is associated with high morbidity and mortality. Antibiotic regimens with penicillin and its derivatives is a leading cause. Antibiotic prophylactic preferences vary across different hospitals within NHS. We compared two antibiotic prophylactic regimens - Cefuroxime only prophylaxis and Teicoplanin with Gentamicin prophylaxis in fracture neck of femur surgery, and evaluated the incidence of C. Difficile diarrhea and Surgical Site Infection (SSI). To assess the Surgical Site Infection and C. Difficile infection rate associated with different regimens of antibiotics prophylaxis in fracture neck of femur surgery. Data was analyzed retrospectively. Neck of femur fracture patients treated surgically from 2009 in our unit were included. Age, gender, co morbidities, type of fracture, operation, ASA grade was collected. 1242 patients received Cefuroxime only prophylaxis between January 2009 and December 2012 (Group 1) and 486 patients received Teicoplanin with Gentamicin between October 2015 and March 2017 (Group 2). There were 353 males and 889 female patients in Group 1 and 138 males and 348 female patients in Group 2. The co morbidities in both groups were comparable. Incidence of C. Difficile diarrhea and Surgical Site Infection (SSI) was noted. Statistical analysis with chi square test was performed to determine the ‘p’ value. C. Diff diarrhea rate in Group 2 was 0.41 % as compared to 1.29 % in Group 1. The Surgical Site Infection (SSI) rate in Group 2 was 0.41 % as compared to 3.06 % in Group 1. The comparative results were statistically significant (p = 0.0009). Prophylactic antibiotic regimen of Teicoplanin with Gentamicin showed significant reduction in C. Difficile diarrhea & Surgical Site Infection in fracture neck of femur patients undergoing surgery


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 10 - 10
17 Apr 2023
Constant C Moriarty T Pugliese B Arens D Zeiter S
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Orthopedic device-related infection (ODRI) preclinical models are widely used in translational research. Most models require induction of general anesthesia, which frequently results in hypothermia in rodents. This study aimed to evaluate the impact of peri anesthetic hypothermia in rodents on outcomes in preclinical orthopedic device-related infection studies. A retrospective analysis of all rodents that underwent surgery under general anesthesia to induce an ODRI model with inoculation of Staphylococcus epidermidis between 2016 and 2020 was conducted. A one-way multivariate analysis of covariance was used to determine the fixed effect of peri anesthetic hypothermia (hypothermic defined as rectal temperature <35°C) on the combined harvested tissue and implant colonies forming unit counts, and having controlled for the study groups including treatments received duration of surgery and anesthesia and study period. All animal experiments were approved by relevant ethical committee. A total of 127 rodents (102 rats and 25 mice) were enrolled in an ODRI and met the inclusion criteria. The mean lowest peri-anesthetic temperature was 35.3 ± 1.5 °C. The overall incidence of peri-anesthetic hypothermia was 41% and was less frequently reported in rats (34% in rats versus 68% in mice). Statistical analysis showed a significant effect of peri anesthetic hypothermia on the post-mortem combined colonies forming unit counts from the harvested tissue and implant(s) (p=0.01) when comparing normo- versus hypothermic rodents. Using Wilks’ Λ as a criterion to determine the contribution of independent variables to the model, peri-anesthetic hypothermia was the most significant, though still a weak predictor, of increased harvested colonies forming unit counts. Altogether, the data corroborate the concept that bacterial colonization is affected by abnormal body temperature during general anesthesia at the time of bacterial inoculation in rodents, which needs to be taken into consideration to decrease infection data variability and improve experimental reproducibility


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 19 - 19
11 Apr 2023
Wyatt F Al-Dadah O
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Unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) are well-established operative interventions in the treatment of knee osteoarthritis (KOA). However, which of these interventions is more beneficial, to patients with KOA, is not known and remains a topic of much debate. Aims: (i) To determine whether UKA or HTO is more beneficial in the treatment of isolated medial compartment KOA, via an assessment of patient-reported outcome measures (PROMs). (ii) To investigate the relationship between PROMs and radiographic parameters of knee joint orientation/alignment. This longitudinal observational study assessed a total of 42 patients that had undergone UKA (n=23) or HTO (n=19) to treat isolated medial compartment KOA. The PROMs assessed, pre-operatively and 1-year post-operatively, consisted of the: self-administered comorbidity questionnaire; short form-12; oxford knee score; knee injury and osteoarthritis outcome score; and the EQ-5D-5L. The radiographic parameters of knee joint alignment/orientation assessed, pre-operatively and 8-weeks post-operatively, included the: hip-knee-ankle angle; mechanical axis deviation; and the angle of the Mikulicz line. Statistical analysis demonstrated an overall significant (p<0.001), pre-operative to post-operative, improvement in the PROM scores of both groups. There were no significant differences in the post-operative PROM scores of the UKA and HTO group. Correlation analyses revealed that pre-operatively, a more distolaterally angled Mikulicz line was associated with worse knee function (p<0.05) and overall health (p<0.05); a relationship that, until now, has not been investigated nor commented upon within the literature. UKAs and HTOs are both efficacious operations that provide a comparable degree of clinical benefit to patients with isolated medial compartment KOA. To further the scientific/medical community's understanding of the factors that impact upon health-outcomes in KOA, future research should seek to investigate the mechanism underlying the relationship, between Mikulicz line and PROMs, observed within the current study


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 33 - 33
4 Apr 2023
Pareatumbee P Yew A Koh J Zainul-Abidin S Howe T Tan M
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To quantify bone-nail fit in response to varying nail placements by entry point translation in straight antegrade humeral nailing using three-dimensional (3D) computational analysis. CT scans of ten cadaveric humeri were processed in 3D Slicer to obtain 3D models of the cortical and cancellous bone. The bone was divided into individual slices each consisting of 2% humeral length (L) with the centroid of each slice determined. To represent straight antegrade humeral nail, a rod consisting of two cylinders with diameters of 9.5mm and 8.5mm and length of 0.22L mm and 0.44L mm respectively joined at one end was modelled. The humeral head apex (surgical entry point) was translated by 1mm in both anterior-posterior and medio-lateral directions to generate eight entry points. Total nail protrusion surface area, maximum nail protrusion distance into cortical shell and top, middle, bottom deviation between nail and intramedullary cavity centre were investigated. Statistical analysis between the apex and translated entry points was conducted using paired t-test. A posterior-lateral translation was considered as the optimal entry point with minimum protrusion in comparison to the anterior-medial translation experiencing twice the level of protrusion. Statistically significant differences in cortical protrusion were found in anterior-medial and posterior-lateral directions producing increased and decreased level of protrusion respectively compared to the apex. The bottom anterior-posterior deviation distance appeared to be a key predictor of cortical breach with the distal nail being more susceptible. Furthermore, nails with anterior translation generated higher anterior-posterior deviation (>4mm) compared to posterior translation (<3mm). Aside from slight posterolateral translation of the entry point from the apex, inclusion of a distal posterior-lateral bend into current straight nail design could improve nail fitting within the curved humeral bone, potentially improving distal working length within the flat and narrow medullary canal of the distal humeral shaft


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 75 - 75
11 Apr 2023
Hofmann J Bewersdorf T Schmidmaier G Grossner T
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The novel, highly-sensitive and non-destructive method for the quantification of the osteogenic potential of bone marrow mesenchymal stem cells (BM-MSCs), by the evaluation of its hydroxyapatite (HA), in vitro is 99mTc-HDP-Labelling. 99mTc-HDP (tracer) binds rapidly to HA and this uptake can be visualized and quantified. This study was performed to evaluate if this method is suitable to perform a real-time assessment during an ongoing cell culture and if the radioactive tracer may influence the cells and their ability to differentiate. BM-MSCs (n=3) were cultivated in 35mm-dishes. Groups 1 and 3 received DMEM-LG based osteogenic media while Groups 2 und 4 were non-osteogenic controls. Groups 1 and 2 (multi-labelling) were incubated with 5 MBq 99mTc-HDP for 30min on day 7 (d7) and the bound activity was measured using an activimeter. Subsequently the cell-culture was continued and again labelled with 99mTc-HDP on day 14 and 21 (d14, d21). Groups 3 and 4 (single labelling), cultivation of the respective triplicates, ended on day 7, 14 and 21 (d7, d14, d21) followed by 99mTc-HDP-Labelling. Statistical analysis using one-factor ANOVA (p<0.05). Absolute tracer uptake increased steadily in both osteogenic groups: 1 (d7: 0.315; d14: 1.093; d21: 3.283 MBq) and 3 (d7: 0.208; d14: 0.822; d: 212.437 MBq) and was significantly higher than in the corresponding non-osteogenic control-group (Group 2 and 4) at all timepoints. (p<0.001). No significant negative effect of the radioactive tracer could be revealed in group 1 (multi radioactive labelling on d7, d14, d21) compared to Group 3 (singe labelling). The 99mTc-Uptake of groups 2 and 4 was not significantly different at any time. Our data show that the repeated exposition to 99mTc-HDP has no negative influence on the osteogenic differentiation potential of BM-MSCs. Therefore, the method is capable of determining the amount of HA during an ongoing cell culture


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 32 - 32
4 Apr 2023
Pareatumbee P Yew A Meng Chou S Koh J Zainul-Abidin S Howe T Tan M
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To analyse bone stresses in humerus-megaprosthesis construct in response to axial loading under varying implant lengths in proximal humeral replacement following tumour excision. CT scans of 10 cadaveric humeri were processed in 3D Slicer to obtain three-dimensional (3D) models of the cortical and cancellous bone. Megaprostheses of varying body lengths (L) were modelled in FreeCAD to obtain the 3D geometry. Four FE models: group A consisting of intact bone; groups B (L=40mm), C (L=100mm) and D (L=120mm) comprising of humerus-megaprosthesis constructs were created. Isotropic linear elastic behaviour was assigned for all materials. A tensile load of 200N was applied to the elbow joint surface with the glenohumeral joint fixed with fully bonded contact interfaces. Static analysis was performed in Abaqus. The bone was divided at every 5% bone length beginning distally. Statistical analysis was performed on maximum von Mises stresses in cortical and cancellous bone across each slice using one-way ANOVA (0-45% bone length) and paired t-tests (45-70% bone length). To quantify extent of stress shielding, average percentage change in stress from intact bone was also computed. Maximum stress was seen to occur distally and anteriorly above the coronoid fossa. Results indicated statistically significant differences between intact state and shorter megaprostheses relative to longer megaprostheses and proximally between intact and implanted bones. Varying levels of stress shielding were recorded across multiple slices for all megaprosthesis lengths. The degree of stress shielding increased with implant lengthening being 2-4 times in C and D compared to B. Axial loading of the humerus can occur with direct loading on outstretched upper limbs or indirectly through the elbow. Resultant stress shielding effect predicted in longer megaprosthesis models may become clinically relevant in repetitive axial loading during activities of daily living. It is recommended to use shorter megaprosthesis to prevent failure


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 4 - 4
2 Jan 2024
Kucko N Sage K Delawi D Hoebink E Kempen D Van Susante J de Bruijn J Kruyt M
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Pseudoarthrosis after spinal fusion is an important complication leading to revision spine surgeries. Iliac Crest Bone Graft is considered the gold standard, but with limited availability and associated co-morbidities, spine surgeons often utilize alternative bone grafts. Determine the non-inferiority of a novel submicron-sized needle-shaped surface biphasic calcium phosphate (BCP<µm) as compared to autograft in instrumented posterolateral spinal fusion. Adult patients indicated for instrumented posterolateral spinal fusion of one to six levels from T10-S2 were enrolled at five participating centers. After instrumentation and preparation of the bone bed, the randomized allocation side of the graft type was disclosed. One side was grafted with 10cc of autograft per level containing a minimum of 50% iliac crest bone. The other side was grafted with 10cc of BCP<µm granules standalone (without autograft or bone marrow aspirate). In total, 71 levels were treated. Prospective follow-up included adverse events, Oswestry Disability Index (ODI), and a fine-cut Computerized Tomography (CT) at one year. Fusion was systematically scored as fused or not fused per level per side by two spine surgeons blinded for the procedure. The first fifty patients enrolled are included in this analysis (mean age: 57 years; 60% female and 40% male). The diagnoses included deformity (56%), structural instability (28%), and instability from decompression (20%). The fusion rate determined by CT for BCP<μm was 76.1%, which compared favorably to the autograft fusion rate of 43.7%. Statistical analysis through binomial modeling showed that the odds of fusion of BCP<μm was 2.54 times higher than that of autograft. 14% of patients experienced a procedure or possible device-related severe adverse event and there were four reoperations. Oswestry Disability Index (ODI) score decreased from a mean of 46.0 (±15.0) to a mean of 31.7 (±16.9), and 52.4% of patients improved with at least 15-point decrease. This data, aiming to determine non-inferiority of standalone BCP<μm as compared to autograft for posterior spinal fusions, is promising. Ongoing studies to increase the power of the statistics with more patients are forthcoming


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 77 - 77
4 Apr 2023
Sharrock M Fermor H Redmond A Brockett C
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This study aims to assess the changes in mechanical behaviour over time in ‘haemarthritic’ articular cartilage compared to ‘healthy’ articular cartilage. Pin-on-plate and indentation tests were used to determine the coefficient of friction (COF) and deformation of ‘healthy’ and ‘haemarthritic articular cartilage. Osteochondral pins (8 mm) were extracted from porcine tali and immersed in exposure fluid for two hours prior to test. Pins were articulated against a larger bovine femoral plate for 3600 seconds under a load of 50 N. Osteochondral pins (8 mm) were loaded during indentation testing for 3600 seconds under a load of 0.25 N. To mimic the effect of a joint bleed in vitro; serum, whole blood and 50% v/v were used as exposure and lubricant fluids. COF and deformation were expressed as mean (n=3) and statistically analysed using a one-way ANOVA and post-hoc Tukey test (p>0.05). The serum condition yielded a COF of 0.0428 ± 0.02 with 0.08mm ± 0.04 deformation. The 50% v/v condition produced a higher COF of 0.0485 ± 0.02 and 0.21mm ± 0.04 deformation. The lowest COF and deformation were produced by the whole blood condition (0.0292 ± 0.02 and 0.06mm ± 0.006 respectively). Statistical analysis indicated no significant difference across the friction test conditions but a significant difference across all indentation test conditions (ANOVA, p>0.05). Combination of creep deformation and wear was observed on the articular surface up to 24 hours post-test in 50% v/v and whole blood conditions. The average haemophilia patient can experience multiple joint bleeds per year of which this study demonstrates the effect of just one joint bleed. This study has provided evidence of potential reversible and irreversible mechanical changes to articular cartilage surface during a joint bleed


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 63 - 63
4 Apr 2023
Rashid M Cunningham L Walton M Monga P Bale S Trail I
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The purpose of this study is to report the clinical and radiological outcomes of patients undergoing primary or revision reverse total shoulder arthroplasty using custom 3D printed components to manage severe glenoid bone loss with a minimum of 2-year follow-up. After ethical approval (reference: 17/YH/0318), patients were identified and invited to participate in this observational study. Inclusion criteria included: 1) severe glenoid bone loss necessitating the need for custom implants; 2) patients with definitive glenoid and humeral components implanted more than 2 years prior; 3) ability to comply with patient reported outcome questionnaires. After seeking consent, included patients underwent clinical assessment utilising the Oxford Shoulder Score (OSS), Constant-Murley score, American Shoulder and Elbow Society Score (ASES), and quick Disabilities of the Arm, Shoulder, and Hand Score (quickDASH). Radiographic assessment included AP and axial projections. Patients were invited to attend a CT scan to confirm osseointegration. Statistical analysis utilised included descriptive statistics (mean and standard deviation) and paired t test for parametric data. 3 patients had revision surgery prior to the 2-year follow-up. Of these, 2/3 retained their custom glenoid components. 4 patients declined to participate. 5 patients were deceased at the time of commencement of the study. 21 patients were included in this analysis. The mean follow-up was 36.1 months from surgery (range 22–60.2 months). OSS improved from a mean 16 (SD 9.1) to 36 (SD 11.5) (p < 0.001). Constant-Murley score improved from mean 9 (SD 9.2) to 50 (SD 16.4) (p < 0.001). QuickDASH improved from mean 67 (SD 24) to 26 (SD 27.2) (p = 0.004). ASES improved from mean 28 (SD 24.8) to 70 (SD 23.9) (p = 0.007). Radiographic evaluation demonstrated good osseointegration in all 21 included patients. The utility of custom 3D-printed components for managing severe glenoid bone loss in primary and revision reverse total shoulder arthroplasty yields significant clinical improvements in this complex patient cohort


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_2 | Pages 133 - 133
2 Jan 2024
Graziani G
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Decreasing the chance of local relapse or infection after surgical excision of bone metastases is a main goals in orthopedic oncology. Indeed, bone metastases have high incidence rate (up to 75%) and important cross-relations with infection and bone regeneration. Even in patients with advanced cancer, bone gaps resulting from tumor excision must be filled with bone substitutes. Functionalization of these substitutes with antitumor and antibacterial compounds could constitute a promising approach to overcome infection and tumor at one same time. Here, for the first time, we propose the use of nanostructured zinc-bone apatite coatings having antitumor and antimicrobial efficacy. The coatings are obtained by Ionized Jet Deposition from composite targets of zinc and bovine-derived bone apatite. Antibacterial and antibiofilm efficacy of the coatings is demonstrated in vitro against S. Aureus and E. Coli. Anti-tumor efficacy is investigated against MDA- MB-231 cells and biocompatibility is assessed on L929 and MSCs. A microfluidic based approach is used to select the optimal concentration of zinc to be used to obtain antitumor efficacy and avoid cytotoxicity, exploiting a custom gradient generator microfluidic device, specifically designed for the experiments. Then, coatings capable of releasing the desired amount of active compounds are manufactured. Films morphology, composition and ion-release are studies by FEG- SEM/EDS, XRD and ICP. Efficacy and biocompatibility of the coatings are verified by investigating MDA, MSCs and L929 viability and morphology by Alamar Blue, Live/Dead Assay and FEG-SEM at different timepoints. Statistical analysis is performed by SPSS/PC + Statistics TM 25.0 software, one-way ANOVA and post-hoc Sheffe? test. Data are reported as Mean ± standard Deviation at a significance level of p <0.05. Results and Discussion. Coatings have a nanostructured surface morphology and a composition mimicking the target. They permit sustained zinc release for over 14 days in medium. Thanks to these characteristics, they show high antibacterial ability (inhibition of bacteria viability and adhesion to substrate) against both the gram + and gram – strain. The gradient generator microfluidic device permits a fine selection of the concentration of zinc to be used, with many potential perspectives for the design of biomaterials. For the first time, we show that zinc and zinc-based coatings have a selective efficacy against MDA cells. Upon mixing with bone apatite, the efficacy is maintained and cytotoxicity is avoided. For the first time, new antibacterial metal-based films are proposed for addressing bone metastases and infection at one same time. At the same time, a new approach is proposed for the design of the coatings, based on a microfluidic approach. We demonstrated the efficacy of Zn against the MDA-MB-231 cells, characterized for their ability to form bone metastases in vivo, and the possibility to use nanostructured metallic coatings against bone tumors. At the same time, we show that the gradient-generator approach is promising for the design of antitumor biomaterials. Efficacy of Zn films must be verified in vivo, but the dual-efficacy coatings appear promising for orthopedic applications


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_14 | Pages 15 - 15
1 Dec 2022
Graziani G Ghezzi D Sartori M Fini M Perut F Montesissa M Boi M Cappelletti M Sassoni E Di Pompo G Giusto E Avnet S Monopoli D Baldini N
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Infection in orthopedics is a challenge, since it has high incidence (rates can be up to 15-20%, also depending on the surgical procedure and on comorbidities), interferes with osseointegration and brings severe complications to the patients and high societal burden. In particular, infection rates are high in oncologic surgery, when biomedical devices are used to fill bone gaps created to remove tumors. To increase osseointegration, calcium phosphates coatings are used. To prevent infection, metal- and mainly silver-based coatings are the most diffused option. However, traditional techniques present some drawbacks, including scarce adhesion to the substrate, detachments, and/or poor control over metal ions release, all leading to cytotoxicity and/or interfering with osteointegration. Since important cross-relations exist among infection, osseointegration and tumors, solutions capable of addressing all would be a breakthrough innovation in the field and could improve clinical practice. Here, for the first time, we propose the use antimicrobial silver-based nanostructured thin films to simultaneously discourage infection and bone metastases. Coatings are obtained by Ionized Jet Deposition, a plasma-assisted technique that permits to manufacture films of submicrometric thickness having a nanostructured surface texture. These characteristics, in turn, allow tuning silver release and avoid delamination, thus preventing toxicity. In addition, to mitigate interference with osseointegration, here silver composites with bone apatite are explored. Indeed, capability of bone apatite coatings to promote osseointegration had been previously demonstrated in vitro and in vivo. Here, antibacterial efficacy and biocompatibility of silver-based films are tested in vitro and in vivo. Finally, for the first time, a proof-of-concept of antitumor efficacy of the silver-based films is shown in vitro. Coatings are obtained by silver and silver-bone apatite composite targets. Both standard and custom-made (porous) vertebral titanium alloy prostheses are used as substrates. Films composition and morphology depending on the deposition parameters are investigated and optimized. Antibacterial efficacy of silver films is tested in vitro against gram+ and gram- species (E. coli, P. aeruginosa, S. aureus, E. faecalis), to determine the optimal coatings characteristics, by assessing reduction of bacterial viability, adhesion to substrate and biofilm formation. Biocompatibility is tested in vitro on fibroblasts and MSCs and, in vivo on rat models. Efficacy is also tested in an in vivo rabbit model, using a multidrug resistant strain of S. aureus (MRSA, S. aureus USA 300). Absence of nanotoxicity is assessed in vivo by measuring possible presence of Ag in the blood or in target organs (ICP-MS). Then, possible antitumor effect of the films is preliminary assessed in vitro using MDA-MB-231 cells, live/dead assay and scanning electron microscopy (FEG-SEM). Statistical analysis is performed and data are reported as Mean ± standard Deviation at a significance level of p <0.05. Silver and silver-bone apatite films show high efficacy in vitro against all the tested strains (complete inhibition of planktonic growth, reduction of biofilm formation > 50%), without causing cytotoxicity. Biocompatibility is also confirmed in vivo. In vivo, Ag and Ag-bone apatite films can inhibit the MRSA strain (>99% and >86% reduction against ctr, respectively). Residual antibacterial activity is retained after explant (at 1 month). These studies indicate that IJD films are highly tunable and can be a promising route to overcome the main challenges in orthopedic prostheses


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 38 - 38
17 Nov 2023
Al-Namnam NM Luczak AT Collishaw S Li X Lucas M Simpson AHRW
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Abstract. Introduction. Ultrasonic cutting in surgery has great potential. However, a key limitation is heat created by friction between the bone and the blade. Bone has poor thermal conductivity which hinders the dissipation of heat, causing cell death near the cut site In addition, ultrasonic vibration may create microcracks. It was hypothesised that these effects on bone would vary with the frequency and displacement of the ultrasonically powered blade. Therefore varying frequencies and displacements of the tip of the blade were studied to find the combination with fewest microcracks and lowest temperature rise at the bone-tool interface. Aim. To explore the effect of different frequencies and tip displacements of ultrasonic cutting devices on the amount of thermal and mechanical damage. Methods. In vitro tests were conducted on fresh rat femoral shafts using two different frequencies; 20kHz and 35kHz.Two displacement amplitudes of two different frequencies were used: 23.9 μm (p-p) and 7.5 μm (p-p) both at 20kHz and 18.7 μm (p-p) and 27 μm (p-p) both at 35kHz and. Cooling was used to emulate clinical conditions. Histological examination (H & E and TUNEL) was performed to identify live and dead cells. Further rat femoral shafts (n=6) were exposed to the same number of cuts by each tool to identify any micro-damage induced by different electrical currents using Micro-CT and confocal Laser scanning microscope. All experimental data were expressed as mean ± standard deviation. Statistical analysis was performed using one-way ANOVA, followed by Post Hoc multiple comparisons test. Differences between groups were considered statistically significant at p < 0.05. Results. The cut site at 7.5 μm (p-p) in 20kHz displayed only indentation instead of a cut, and was excluded. Histological examination revealed a high incidence of cell death at the cutting edge, in both frequencies. At 35kHz and 27 μm (p-p) some charring was evident, while at 20kHz and 23.9 μm (p-p) more irregularities were seen on the surface of the cut indicating instability during cutting when this setting was used. In contrast, the 35kHz at 18.7 μm (p-p) resulted in a smoother cutting surface. The highest cell death percentage ranged from 25% (at 35kHz, 18.7 μm (p-p)) to 44 % (at 35kHz, 27 μm (p-p)). Most of the tool's effect was located within 25 µm of the cut surface. There was a significant decrease to < 5 % at 200 µm. No cell death was found over 200 µm from the cut surface in both frequencies (35 kHz and 20 kHz). No significant difference in total percentage cell death was found between cutting at 35kHz and 18.7 μm (p-p) and at 20kHz and 23.9 μm (p-p). No microcracks were detected along the depth of the cut site at either frequency. Conclusion. Of the 2 ultrasonic cutting frequencies tested, the combination of the higher vibration frequency (35kHz) and the lower displacement amplitude (18.7 μm (p-p) demonstrated least damage to the bone tissue. No microcracks were displayed when using either of the ultrasonic cutting frequencies. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_14 | Pages 13 - 13
1 Dec 2022
Barone A Cofano E Zappia A Natale M Gasparini G Mercurio M Familiari F
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The risk of falls in patients undergoing orthopedic procedures is particularly significant in terms of health and socioeconomic effects. The literature analyzed closely this risk following procedures performed on the lower limb, but the implications following procedures on the upper limb remain to be investigated. Interestingly, it is not clear whether the increased risk of falling in patients undergoing shoulder surgery is due to preexisting risk factors at surgery or postoperative risk factors, such as anesthesiologic effects, opioid medications used for pain control, or brace use. Only one prospective study examined gait and fall risk in patients using a shoulder abduction brace (SAB) after shoulder surgery, revealing that the brace adversely affected gait kinematics with an increase in the risk of falls. The main purpose of the study was to investigate the influence of SAB on gait parameters in patients undergoing shoulder surgery. Patients undergoing elective shoulder surgery (arthroscopic rotator cuff repair, reverse total shoulder arthroplasty, and Latarjet procedure), who used a 15° SAB in the postoperative period, were included. Conversely, patients age > 65 years old, with impaired lower extremity function (e.g., fracture sequelae, dysmorphism, severe osteo-articular pathology), central and peripheral nervous system pathologies, and cardiac/respiratory/vascular insufficiency were excluded. Participants underwent kinematic analysis at four different assessment times: preoperative (T0), 24 hours after surgery (T1), 1 week after surgery (T2), and 1 week after SAB removal (T3). The tests used for kinematic assessment were the Timed Up and Go (TUG) and the 10-meter test (10MWT), both of which examine functional mobility. Agility and balance were assessed by a TUG test (transitions from sitting to standing and vice versa, walking phase, turn-around), while gait (test time, cadence, speed, and pelvic symmetry) was evaluated by the 10MWT. Gait and functional mobility parameters during 10MWT and TUG tests were assessed using the BTS G-Walk sensor (G-Sensor 2). One-way ANOVA for repeated measures was conducted to detect the effects of SAB on gait parameters and functional mobility over time. Statistical analysis was performed with IBM®SPSS statistics software version 23.0 (SPSS Inc., Chicago, IL, USA), with the significant level set at p<0.05. 83% of the participants had surgery on the right upper limb. A main effect of time for the time of execution (duration) (p=0.01, η2=0.148), speed (p<0.01, η2=0.136), cadence (p<0.01, η2=0.129) and propulsion-right (R) (p<0.05, η2=0.105) and left (L) (p<0.01, η2=0.155) in the 10MWT was found. In the 10MWT, the running time at T1 (9.6±1.6s) was found to be significantly longer than at T2 (9.1±1.3s, p<0.05) and at T3 (9.0±1.3s, p=0.02). Cadence at T1 (109.7±10.9steps/min) was significantly lower than at T2 (114.3 ±9.3steps/min, p<0.01) and T3 (114.3±9.3steps/min, p=0.02). Velocity at T1 (1.1±0.31m/s) was significantly lower than at T2 (1.2± 0.21m/s, p<0.05). No difference was found in the pelvis symmetry index. No significant differences were found during the TUG test except for the final rotation phase with T2 value significantly greater than T3 (1.6±0.4s vs 1.4±0.3s, p<0.05). No statistically significant differences were found between T0 and T2 and between T0 and T3 in any of the parameters analyzed. Propulsion-R was significantly higher at T3 than T1 (p<0.01), whereas propulsion-L was significantly lower at T1 than T0 (p<0.05) and significantly higher at T2 and T3 than T1 (p<0.01). Specifically, the final turning phase was significantly higher at T2 than T3 (p<0.01); no significant differences were found for the duration, sit to stand, mid-turning and stand to sit phases. The results demonstrated that the use of the abduction brace affects functional mobility 24 hours after shoulder surgery but no effects were reported at longer term observations


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 141 - 141
1 Nov 2021
Moretti B
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Aim. This study aims to define the normal postoperative presepsin kinetics in patients undergoing primary cementless total hip replacement (THR). Methods. Patients undergoing primary cementless THR at our Institute were recruited. At enrollment anthropometric data, smocking status, osteoarthritis stage according to Kellgren and. Lawrence, Harris Hip Score (HHS), drugs assumption and comorbidities were recorded. All the patients underwent serial blood tests, including complete blood count, presepsin (PS) and C-Reactive Protein (CRP) 24 hours before arthroplasty and at 24-, 48-, 72- and 96-hours postoperatively and at 3-, 6- and 12-months follow-up. Statistical analysis was performed with SPSS v25.0 (SPSS Inc, Chicago, IL, USA). The Wilcoxon and Kruskal-Wallis tests followed by the Dunn multiple comparison post hoc tests were carried out. Correlations between PS, CRP and TOT were assessed using the Spearman rank correlation coefficient. P values below 0.05 were considered significant. Results and conclusion. A total of 96 patients were recruited (51 female; 45 male; mean age= 65.74±5.58) were recruited. The mean PS values were: 137.54 pg/ml at baseline, 192.08 pg/ml at 24-hours post-op; 254.85 pg/ml at 48-hours post-op; 259 pg/ml at 72-hours post-op; 248.6 pg/ml at 96-hour post-op; 140.52 pg/ml at 3-months follow-up; 135.55 pg/ml at 6-months follow-up and 130.11 pg/ml at 12-months follow-up. In two patients (2.08%) a soft-tissue infection was observed; in these patients higher levels (>350pg/mL) were recorded at 3-months follow-up. The lack of a presepsin decrease at 96 hours post-operatively should be a predictive factor of infection


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 60 - 60
1 Nov 2021
Cazzanelli P Hausmann ON Wuertz-Kozak K
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Introduction and Objective. Intervertebral disc (IVD) degeneration is one of the major contributors to low back pain, the leading cause of disability worldwide. This multifactorial pathological process involves the degradation of the extracellular matrix, inflammation, and cell loss due to apoptosis and senescence. While the deterioration of the extracellular matrix and cell loss lead to structural collapse of the IVD, increased levels of inflammation result in innervation and the development of pain. Amongst the known regulators of inflammation, toll-like receptors (TLRs) and more specifically TLR-2 have been shown to be specifically relevant in IVD degeneration. As strong post-transcriptional regulators, microRNAs (miRNAs) and their dysregulation has been connected to multiple pathologies, including degenerative diseases such as osteoarthritis and IVD degeneration. However, the role of miRNAs in TLR signalling in the IVD is still poorly understood and was hence investigated in this study. Materials and Methods. Human Nucleus pulposus (hNP) and Annulus fibrosus (hAF) cells (n=5) were treated with the TLR-2/6 specific agonist PAM2CSK4 (100 ng/mL for 6 hours) in order to activate the TLR2 signalling pathway. After the activation both miRNA and mRNA were isolated, followed by next-generation sequencing and qPCR analysis of proinflammatory cytokines respectively. Furthermore, cell supernatants were used to analyze the secretion of proinflammatory cytokines with enzyme-linked immunosorbent assay. TLR-2 knockdown (siRNA) cells were used as a control. Statistical analysis was conducted by performing Kolmogorov-Smirnov test and a two-tailed Student's t-test using GraphPad Prism version 9.0.2 for Windows (GraphPad Software, La Jolla California USA). Results. TLR-2 activation resulted in the induction of an inflammatory cell response, with a significant increase in gene expression of interleukin (IL)-6 (525 ± 180 fold change, p < 0.05) and IL-8 (7513 ± 1907 fold change, p < 0.05) and protein secretion of IL-6 (30.5 ± 8.1 pg/mL) and IL-8 (28.9 ± 5.4 pg/mL). TLR-2 activation was furthermore associated with changes in the miRNA profile of hNP and hAF cells. Specifically, we identified 10 differentially expressed miRNAs in response to TLR-2 activation, amongst which were miR-335–3p (1.45 log2 FC, p < 0.05), miR-125b-1–3p (0.55 log2 FC, p < 0.05), and miR-181a-3p (−1.05 log2 FC, p < 0.05). Conclusions. The identified miRNAs are known to be associated with osteoarthritis (miR-335-3p), inflammation and IVD degeneration (mir-125-1-3p and miR-181a-3p), but the link to TLR signalling has not been previously reported. Experiments to validate the identified miRNAs and elucidate their functional role are undergoing. The identification of these miRNAs provides an opportunity to further investigate miRNAs in the context of TLR activation and inflammation and to enhance our understanding of underlying molecular mechanisms behind disc degeneration, inflammation, and TLR dysregulation


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 118 - 118
1 Nov 2021
Pareatumbee P Yew A Koh JSB Howe TS Abidin SZ Tan MH
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Introduction and Objective. Curative resection of proximal humerus tumours is now possible in this era of limb salvage with endoprosthetic replacement considered as the preferred reconstructive option. However, it has also been linked with mechanical and non-mechanical failures such as stem fracture and aseptic loosening. One of the challenges is to ensure that implants will endure the mechanical strain under physiological loading conditions, especially crucial in long surviving patients. The objective is to investigate the effect of varying prosthesis length on the bone and implant stresses in a reconstructed humerus-prosthesis assembly after tumour resection using finite element (FE) modelling. Methods. Computed tomography (CT) scans of 10 humeri were processed in Mimics 17 to create three-dimensional (3D) cortical and cancellous solid bone models. Endoprostheses of different lengths manufactured by Stryker were modelled using Solidworks 2020. The FE models were divided into four groups namely group A consisting of the intact humerus and groups B, C and D composed of humerus-prosthesis assemblies with a body length of 40, 100 and 120 mm respectively and were meshed using linear 4-noded tetrahedral elements in 3matic 13. The models were then imported into Abaqus CAE 6.14. Isotropic linear elastic behaviour with an elastic modulus of 13400, 2000 and 208 000 MPa were assigned to the cortical bone, cancellous bone and prosthesis respectively and a Poisson's ratio of 0.3 was assumed for each material. To represent the lifting of heavy objects and twisting motion, a tensile load of 200 N for axial loading and a 5 Nm torsional load for torsional loading was applied separately to the elbow joint surface with the glenohumeral joint fixed and with all contact interfaces defined as fully bonded. A comparative analysis against literature was performed to validate the intact model. Statistical analysis of the peak von Mises stress values collected from predicted stress contour plots was performed using a one-way repeated measure of analysis of variance (with a Bonferroni post hoc test) using SPSS Statistics 26. The average change in stress of the resected models from the intact state were then determined. Results. The validation of the intact humerus displayed a good agreement with literature values. The peak bone stress occurred distally above the coronoid and olecranon fossa closer to the load application region in the intact and resected bone models with a significant amount of loading borne by the cortical bone, while the peak implant stress occurred at the bone-prosthesis contact interface under both loading conditions. Based on the results obtained, a statistically significant difference (p =.013) in implant stress was only seen to occur between groups B and C under tension. Results illustrate initiation of stress shielding with the bone bearing lesser stress with increasing resection length which may eventually lead to implant failure by causing bone resorption according to Wolff's law. The peak implant stress under torsion was 3–5 times the stress under tension. The best biomechanical behaviour was exhibited in Group D, having the least average change in stress from the intact model, 5% and 3.8% under tension and torsion respectively. It can be deduced that the shorter the prosthesis length, the more pronounced the effect on cortical bone remodelling. With the maximum bone and implant stresses obtained being less than their yield strength, it can be concluded that the bone-implant construct is safe from failure. Conclusions. The developed FE models verified the influence of varying the prosthesis length on the bone and implant stresses and predicted signs of stress shielding in longer endoprostheses. By allowing for 2 cm shortening in the upper extremity and post-surgical scarring, it is beneficial to err towards a shorter endoprosthesis


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_4 | Pages 120 - 120
1 Mar 2021
Grammens J Peeters W Van Haver A Verdonk P
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Trochlear dysplasia is a specific morphotype of the knee, characterized by but not limited to a specific anatomy of the trochlea. The notch, posterior femur and tibial plateau also seem to be involved. In our study we conducted a semi-automated landmark-based 3D analysis on the distal femur, tibial plateau and patella. The knee morphology of a study population (n=20), diagnosed with trochlear dysplasia and a history of recurrent patellar dislocation was compared to a gender- and age-matched control group (n=20). The arthro-CT scan-based 3D-models were isotropically scaled and landmark-based reference planes were created for quantification of the morphometry. Statistical analysis was performed to detect shape differences between the femur, tibia and patella as individual bone models (Mann-Whitney U test) and to detect differences in size agreement between femur and tibia (Pearson's correlation test). The size of the femur did not differ significantly between the two groups, but the maximum size difference (scaling factor) over all cases was 35%. Significant differences were observed in the trochlear dysplasia (TD) versus control group for all conventional parameters. Morphometrical measurements showed also significant differences in the three directions (anteroposterior (AP), mediolateral (ML), proximodistal (PD)) for the distal femur, tibia and patella. Correlation tests between the width of the distal femur and the tibial plateau revealed that TD knees show less agreement between femur and tibia than the control knees; this was observed for the overall width (TD: r=0.172; p=0.494 - control group: r=0.636; p=0.003) and the medial compartment (TD: r=0.164; p=0.516 - control group: r=0.679; p=0.001), but not for the lateral compartment (TD: r=0.512; p=0.029 - control: r=0.683; p=0.001). In both groups the intercondylar eminence width was strongly correlated with the notch width (TD: r=0.791; p=0.001 - control: r=0.643; p=0.002). The morphology of the trochleodysplastic knee differs significantly from the normal knee by means of an increased ratio of AP/ML width for both femur and tibia, a smaller femoral notch and a lack of correspondence in mediolateral width between the femur and tibia. More specifically, the medial femoral condyle shows no correlation with the medial tibial plateau


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_4 | Pages 45 - 45
1 Mar 2021
Russo F Ambrosio L Ngo K Vadalà G Denaro V Fan Y Sowa G Kang JD Vo N
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Intervertebral disc degeneration (IDD) is a major cause of low back pain, which affects 80% of the adult population at least once in their life. The pathophysiological conditions underlying IDD are still poorly understood. Genetic makeup, aging, smoking, physical inactivity and mechanical overloading, especially due to obesity, are among the strongest risk factors involved. Moreover, IDD is often associated with chronic inflammation within disc tissues, which increases matrix breakdown, glycosaminoglycan (GAG) loss and cell death. This micro-inflammatory environment is typical of several metabolic disorders, including diabetes mellitus (DM). As the etiopathogenesis of IDD in diabetic subjects remains scarcely understood, we hypothesised that this may be driven by a DM-induced inflammation leading to a combination of reduced GAG levels, decreased proteoglycan synthesis and increased matrix breakdown within the disc. The objective of the study was to investigate the pathogenesis of IDD in a murine model of type 1 DM (T1DM), namely non-obese diabetic (NOD) mouse. Total disc glycosaminoglycan (GAG) content, proteoglycan synthesis, aggrecan fragmentation mediated by matrix metalloproteinases (MMPs) and a Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS), glucose transporter (mGLUT1) gene expression and apoptosis (TUNEL assay) were assessed in NOD mice and wild-type euglycemic control mice. Spinal structural and molecular changes were analysed by micro-computed tomography (mCT), histological staining (Safranin-O and fast green) and quantitative immunofluorescence (anti-ADAMTS-4 and 5 antibodies). Statistical analysis was conducted considering the average of 35 samples ± standard error for each measurement, with 95% confidence intervals calculated to determine statistical significance (p-value < 0.05). IVDs of NOD mice showed increased disc apoptosis (p < 0.05) and higher aggrecan fragmentation mediated by ADAMTS (p < 0.05). However, ADAMTS-4 and −5 did not appear to be involved in this process. The total GAG content normalized to DNA and PG synthesis showed no statistically significant alterations, as well as Safranin O staining. Although not significantly, NOD mice showed reduced glucose uptake. In addition, the vertebral structure of NOD mice at mCT seemed not to be altered. These data demonstrate that DM may contribute to IDD by increasing aggrecan degradation and promoting cell apoptosis, which may represent early indicators of the involvement of DM in the pathogenesis of IDD