Abstract. Objective. Meta-analysis of clinical trials highlights that non-operative management of degenerative knee meniscal tears is as effective as surgical management. Surgical guidelines though support arthroscopic partial meniscectomy which remains common in NHS practice. Physiotherapists are playing an increasing role in triage of such patients though it is unclear how this influences clinical management and patient outcomes. Methods. A 1-year cohort (July 2019–June 2020) of patients presenting with MRI confirmed degenerative meniscal tears to a regional orthopaedic referral centre (3× ESP physiotherapists) was identified. Initial clinical management was obtained from medical records alongside subsequent secondary care management and routinely collected outcome scores in the following 2-years. Management options included referral for surgery, conservative (steroid injection and rehabilitation), and no active treatment. Outcome scores collected at 1- and 2-years included the Forgotten Joint Score-12 (FJS-12) questionnaire and 0–10 numerical rating scales for worst and average pain. Treatment allocation is presented as absolute and proportional figures. Change in outcomes across the cohort was evaluated with repeated measures ANOVA, with Bonferroni correction for multiple testing, and post-hoc Tukey pair-wise comparisons. As treatment decision is discrete, no direct contrast is made between outcomes of differing interventions but additional explorative outcome change over time evaluated by group. Significance was accepted at p=0.05 and effect size as per Cohen's values. Results. 81 patients, 50 (61.7%) male, mean age 46.5 years (SD13.13) presented in the study timeframe. 32 (40.3%) received conservative management and 49 (59.7%) were listed for surgery. Six (18.8%) of the 32 underwent subsequent surgery and nine of the 49 (18.4%) patients switched from planned surgery to receiving non-operative care. Two post-operative complications were noted, one cerebrovascular accident and one deep vein thrombosis. The cohort improved over the course of 2-years in all outcome measures with improved mean FJS-12 (34.36 points), mean worst pain (3.74 points) average pain (2.42 points) scores. Overall change (all patients) was statistically significant for all outcomes (p<0.001), with sequential year-on-year change also significant (p<0.001). Effect size of these changes were large with all Cohen-d values over 1. Controlling for age and BMI, males reported superior change in FJS-12 (p=0.04) but worse pain outcomes (p<0.03). Further explorative analysis highlighted positive outcomes across all surgical, conservative and no active treatment groups (p<0.05). The 15 (18%) patients that switched between surgical and non-surgical management also reported positive outcome scores (p<0.05). Conclusion(s). In a regional specialist physiotherapy-led soft tissue knee clinic around 60% of degenerative meniscal tears assessed were referred for surgery. Over 2-years, surgical, non-operative and no treatment management approaches in this cohort all resulted in clinical improvement suggesting that no single strategy is effective in directly treating the meniscal pathology, and that perhaps none do. Clinical intervention rather is directed at individual symptom management based on clinical preferences. 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

Abstract. Objectives. Principal Component Analysis (PCA) is a useful method for analysing human motion data. The objective of this study was to use PCA to quantify the biggest variance in knee kinematics waveforms between a Non-Pathological (NP) group and individuals awaiting High Tibial Osteotomy (HTO) surgery. Methods. Thirty knees (29 participants) who were scheduled for HTO surgery were included in this study. Twenty-eight NP volunteers were recruited into the study. Human motion analysis was performed during level gait using a modified Cleveland marker set. Subjects walked at their self-selected speed for a minimum of 6 successful trials. Knee kinematics were calculated within Visual3D (C-Motion). The first three Principal Components (PCs) of each input variable were selected. Single-component reconstruction was performed alongside representative extremes of each PC to aid interpretation of the biomechanical feature reconstructed by each component. Results. Pre-operatively patient demographics included (age: 50.70 (8.71) years; height: 1.75 (.11) m; body mass: 90.57 (20.17) kg; mTFA: 7.75 (3.72) degrees varus; gait speed: 1.06 (0.23) m/s). The HTO cohort was significantly older and had a higher mass than the NP control participants. For knee kinematics the first three PCs explained 88%, 95% and 89% of the sagittal, frontal, and transverse planes, respectively. The main variances can be explained by sagittal plane magnitude differences, peak swing is associated with toe-off, a reduced knee flexion angle is associated with a longer time spent in stance, pre-HTO remain adducted during stance and pre-HTO patients remain more externally rotated during stance and latter part of swing. Conclusions. This study has introduced PCA in trying to better understand the biomechanical differences between a control group and a cohort with medial knee osteoarthritis varus deformity awaiting HTO. Further analysis will be undertaken using PCA comparing pre- and post-surgery which will be of importance in clinical decision making

Background

Recurrent patellar dislocation in combination with cartilage injures are difficult injuries to treat with confounding pathways of treatment. The aim of this study is to compare the clinical and functional outcomes of patients operated for patellofemoral instability with and without cartilage defects.

Critical shoulder angle (CSA), lateral acromial angle (LAA), and acromion index (AI) are common radiologic parameters used to distinguish between patients with rotator cuff tears (RCT) and those with an intact rotator cuff. This study aims to assess the predictive power of these parameters in degenerative RCT.

This retrospective study included data from 92 patients who were divided into two groups: the RCT group, which included 47 patients with degenerative full-thickness supraspinatus tendon tears, and a control group of 45 subjects without tears. CSA, AI, and LAA measurements from standardized true anteroposterior radiographs were independently derived and analyzed by two orthopedic surgeons. Receiver operating characteristic (ROC) analyses were performed to determine the cutoff values.

No significant differences were found between patients in the RCT and control groups in age (p = 0.079), gender (p = 0.804), or injury side (p = 0.552). Excellent inter-observer reliability was seen for CSA, LAA, and AI values. Mean CSA (38.1°) and AI (0.72) values were significantly larger in the RCT group than in the control group (34.56° and 0.67°, respectively, p < 0.001) with no significant difference between groups for LAA (RCT, 77.99° vs. control, 79.82°; p = 0.056). ROC analysis yielded an area under the curve (AUC) of 0.815 for CSA with a cutoff value of 37.95°, and CSA was found to be the strongest predictor of the presence of a RCT, followed by AI with an AUC of 0.783 and a cutoff value of 0.705.

We conclude that CSA and AI may be useful predictive factors for degenerative RCT in the Turkish population.

Summary Statement. This data may help explain the variability in physical function after primary TKR as compared to primary THR. Introduction. Total knee replacement (TKR) and total hip replacement (THR) reliably relieve pain, restore function, and ensure mobility in patients with advanced joint arthritis; however these results are not uniform across all patient populations. We compared baseline demographic and symptom profiles in patients from a US national cohort undergoing primary TKR and THR. Methods. Patients undergoing primary TKR and THR between 7/1/2011 and 3/30/2012 were identified from the national research consortium which collects comprehensive data on enrolled patients from 120 surgeons across 23 states. Gathered data includes patient demographics, comorbidity (Charlson Comorbidity Index), operative joint pain severity, physical function (SF-36; Physical Component Score (PCS)), emotional health (SF-36 Mental Component Score (MCS)), and musculoskeletal burden of illness (Hip and Knee Disability and Osteoarthritis Outcome Scores; Oswestry Disability Index). Descriptive statistics compared baseline demographic and symptom profiles. Results. Our analysis compared 1362 primary TKR patients and 1013 primary THR patients. US TKR patients were significantly older (66.5 vs. 64.3 years), more obese (BMI 31.7 vs. 29.3), and less educated (p<0.005). TKR patients had higher rates of comorbidities, specifically diabetes, gastrointestinal ulcers, and cerebrovascular disease (p≤0.006). THR patients had significantly worse physical function (PCS 31.6 vs. 33.3), lower back pain (35.6% vs. 30.5% moderate-severe), and operative joint pain, stiffness, and function (p<0.005). Conclusion. US patients undergoing primary TKR are older with more comorbidities, however THR patient baseline functional and musculoskeletal limitations are significantly greater than primary TKR patients

Patellofemoral osteoarthritis (PFOA) affects 32% men and 36% women over the age of 60years and is associated with anterior knee pain, stiffness, and poor mobility. Patellofemoral arthroplasty (PFA) is a bone-sparing treatment for isolated PFOA. This study set out to investigate the relationship between patient-related outcome measures (PROMs) and measurements obtained from gait analysis before and after PFA. There are currently no studies relating to gait analysis and PFA available in the literature

A prospective cohort study was conducted of ten patients known to have isolated PFOA who had undergone PFA compared to a gender and age matched control group. The patients were also asked to complete questionnaires (Oxford knee score (OKS), EQ-5D-5L) before surgery and one year after surgery. Gait analysis was done on an instrumented treadmill comparing Ground reaction force parameters between the control and pre and post-operative PFA patients

The average age 60 (49–69) years with a female to male ratio of 9:1. Patient and healthy subjects were matched for age and gender, with no significant difference in BMI. Post-op PFA improvement in gait seen in ground reaction force at 6.5km/h. Base support difference was statistically significant both on the flat P=0.0001 and uphill P=0.429 (5% inclination) and P=0.0062 (10% inclination). PROMS response rate was 70%(7/10) pre-operative and 60%(6/10) post-operative. EQ-5D-5L scores reflected patient health state was better post-operatively.

This study found that gait analysis provides an objective measure of functional gait and reflected by significant quality-of-life improvement of patients post PFA. Literature lacks studies relating to gait-analysis and PFA. Valuable information provided by this study highlights that PFA has a beneficial outcome reflected by PROMs and improvement in vertical ground reaction force and gait

Further research is needed to assess how care-providers may use gait-analysis as part of patient care plans for PFOA patients.

Introduction

An additional pathology should be considered for Achillodynia differentials – the intratendinous tear (ITT) – for which we describe symptoms, ultrasound findings and co-presenting pathology.

Various arthroscopic techniques using differing graft materials have been described and present a potential alternative to arthroplasty for rotator cuff arthropathy. We describe the short-term outcomes of allograft reconstruction, having evolved of our surgical technique from graft interposition to superior capsule reconstruction (SCR). All patients with an irreparable tear, in the absence of clinical and radiograph evidence of osteoarthritis, who underwent an allograft (Graft Jacket^TM) reconstruction with either an arthroscopic interposition or SCR technique within our institution were included. A retrospective case note analysis was performed to ascertain perioperative details including total operating and consumable implant costs. 15 patients were in the interposition group, mean age 66 years (48–77). Mean postoperative follow-up time was 17 months (1.9 −27.8). The mean OSS improved from 30.6 to 35.7 (p<0.05). Additionally, mean pain scores out of 10 improved from 7.7 to 1.5 (p<0.01). Mean satisfaction for the surgery was 7.8 out of 10. Complications included 2 re-ruptures (13.3%), 1 infection (6.7%) and 1 case of no improvement (6.7%). In the SCR group, there were 10 patients, mean age 64.5 (56– 68 years). Half of these patients had previous rotator cuff surgery. Mean postoperative follow-up time was 8.7 months (1.9 – 16.3). The mean OSS improved from 24 to 32.9 (p<0.01). Similarly, pain scores decreased from 7.9 to 3.5 (p<0.01). Mean satisfaction was 7.2. Complications included 1 case of no improvement (10%) resulting in a reverse TSR and 1 re-rupture (10%). A formal, prospective comparison trial is advocated to determine if SCR is superior.

Metal-on-metal (MOM) hip arthroplasty, including resurfacing, has become the subject of recent research and debate. There is the perceived benefit of improved wear rates of bearing surfaces leading to superior durability and performance of these types of implant. An associated feature of MOM bearing surfaces is the generation of metal ions. These can have local and systemic cytotoxic effects. An immunoloigical response has been suggested, however, metal wear debris may cause direct damage to cellular DNA. Studies have shown that release of these ions is related to bearing diameter and component alignment. However, little is known about the relationship between metal ion levels and implant survivorship. The MHRA has published guidelines on the follow-up of patients with MOM implants including measurement of serum ion levels and cross sectional imaging.

Between February 2001 and November 2009, 135 patients (164 hips) had MOM resurfacing arthroplasty at our institution. We report a retrospective analysis of the data generated by review of these patients. Of the 135 patients, 91 were identified for clinical review. Each patient had serum metal ion levels measured, plain AP radiographs of the pelvis examined and, in the presence of raised metal ions, a Metal Artefact Reduction Sequence (MARS) MRI performed. 27 patients (35 hips) had raised metal ion levels (Cobalt and Chromium). Patients with raised metal ion levels had a mean acetabular cup inclination of 52.7 degrees compared with a mean inclination of 48.6 degrees in patients with normal ion levels (p<0.05). MARS MRI in the raised ion group revealed 9 patients with appearances suggestive of ALVAL. A number of these patients had hip revision surgery with the remainder awaiting potential revision.

These findings reflect current evidence suggesting a relationship between sub-optimal component position and raised metal ion levels and an increased rate of ALVAL.

A major cause of morbidity in lower limb amputees is phantom limb pain (PLP) and residual limb pain (RLP). This study aimed to determine if surgical interposition of nerve endings into adjacent muscle bellies at the time of major lower limb amputation can decrease the incidence and severity of PLP and RLP. Data was retrospectively collected from January 2015 to January 2021, including eight patients that underwent nerve interposition (NI) and 36 that received standard treatment. Primary outcomes included the 11-point Numerical Rating Scale (NRS) for pain severity, and Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity, behaviour, and interference. Secondary outcome included Neuro-QoL Lower Extremity Function assessing mobility. Cumulative scores were transformed to standardised t scores. Across all primary and secondary outcomes, NI patients had lower PLP and RLP. Mean ‘worst pain’ score was 3.5 out of 10 for PLP in the NI cohort, compared to 4.89 in the control cohort (p=0.298), and 2.6 out of 10 for RLP in the NI cohort, compared to 4.44 in the control cohort (p=0.035). Mean ‘best pain’ and ‘current pain’ scores were also superior in the NI cohort for PLP (p=0.003, p=0.022), and RLP (p=0.018, p=0.134). Mean PROMIS t scores were lower for the NI cohort for RLP (40.1 vs 49.4 for pain intensity; p=0.014, 44.4 vs 48.2 for pain interference; p=0.085, 42.5 vs 49.9 for pain behaviour; p=0.025). Mean PROMIS t scores were also lower for the NI cohort for PLP (42.5 vs 52.7 for pain intensity; p=0.018); 45.0 vs 51.5 for pain interference; p=0.015, 46.3 vs 51.1 for pain behaviour; p=0.569). Mean Neuro-QoL t score was lower in NI cohort (45.4 vs 41.9;p=0.03). Surgical interposition of nerve endings during lower limb amputation is a simple yet effective way of minimising PLP and RLP, improving patients’ subsequent quality of life. Additional comparisons with targeted muscle reinnervation should be performed to determine the optimal treatment option

The goal was to analyze the cellular response, specifically the osteogenic capacity, of titanium (Ti) implants harbouring a novel laserbased-surface-structure with the overall aim: augmented osteointegration. Surface micro-/nanoproperties greatly influence cell behaviour at the tissue-implant-interface and subsequent osteointegration. We investigated Ti-materials subjected to a specially developed shifted-Laser-Surface-Texturing (sLST) technology and compared them to a standard roughening-technique (sand-blasting-acid-etching, SLA). The biological response was evaluated with hMSCs, which are naturally available at the bone-implant-interface. We hypothesized: the novel surface is beneficial for our three different (young/healthy-YH; aged/healthy-AH;aged/osteoporotic-OP) cohorts. The sLST was performed using a SPI-G3-series laser (beam-wavelength=1064nm, pulse-duration=200ns). For the SLA surface, Ti was sandblasted, afterwards acid-etched (HCl/H2SO4). Three different hMSC cohorts were studied: YH: n=6,29±6; AH: n=5,79±5; OP: n=5,76±5 years (osteoporosis confirmed via DEXA-scan). OP hMSCs show e.g. ColI-deficient-matrix and decreased mineralization. Cells were examined for survival, cell proliferation and cytoskeleton arrangement. Osteogenic differentiation was carried out over 21 days, matrix mineralization was validated with Alizarin-Red-S-staining and quantification. Laser-texturing generated precisely the desired microgeometry. On nanostructural level, differently-sized Ti-droplets were formed stochastically by laser-induced-Ti-plasma. Live/dead-/Actin-stainings showed comparable results for all cohorts and surfaces in terms of survival and cell shape. On Ti-materials, cell growth showed no significant difference between the 3 cohorts. Alizarin quantification revealed the highest levels on laser-textured-surfaces; highest value for YH, followed by AH, lastly OP; no significance between AH/YH, but between OP/YH (p<0.0001). However, mineralization of all cohorts cultured on laser-textured-surfaces increased significantly (p<0.0001) compared to respective SLA-group, with >20fold higher value in the OP-cohort (AH:11fold, YH:6fold). The data proves the biocompatibility of the laser-structured-Ti for young+aged cohorts. Osteogenic differentiation was significantly augmented on laser-treated-Ti. Most intriguingly, OP-donors could reach manifold increased mineralization, suggesting the novel laser texturing can counteract the osteoporotic phenotype. As osteogenesis-enhancing capacities may be related to mechanisms controlling cellular shape/fate, further investigations referring to this are currently ongoing. In conclusion, our laser-textured-Ti-materials are safe, can have a demand-oriented designer-surface-topography and represent a great potential for development into next-generation-implants suitable for different patient-cohorts, especially osteoporosis patients

Abstract. Objective. Up to 20% of patients can remain dissatisfied following TKR. A proportion of TKRs will need early revision with aseptic loosening the most common. The ATTUNE TKR was introduced in 2011 as successor to its predicate design The PFC Sigma (DePuy Synthes, Warsaw, In). However, following reports of early failures of the tibial component there have been ongoing concerns of increased loosening rates with the ATTUNE TKR. In 2017 a redesigned tibial baseplate (S+) was introduced, which included cement pockets and an increased surface roughness to improve cement bonding. Given the concerns of early tibial loosening with the ATTUNE knee system, this study aimed to compare revision rates and those specific to aseptic loosening of the ATTUNE implant in comparison to an established predicate as well as other implant designs used in a high-volume arthroplasty centre. Methods. The Attune TKR was introduced to our unit in December 2011. Prior to this we routinely used a predicate design with an excellent long-term track record (PFC Sigma) which remains in use. In addition, other designs were available and used as per surgeon preference. Using a prospectively maintained database, we identified 10,202 patients who underwent primary cemented TKR at our institution between 01/04/2003–31/03/2022 with a minimum of 1 year follow-up (Mean 8.4years, range 1–20years): 1) 2406 with ATTUNE TKR (of which 557 were S+) 2) 4652 with PFC TKR 3) 3154 with other cemented designs. All implants were cemented using high viscosity cement. The primary outcome measures were all-cause revision, revision for aseptic loosening, and revision for tibial loosening. Kaplan-Meier survival analysis and Cox regression models were used to compare the primary outcomes between groups. Matched cohorts were selected from the ATTUNE subsets (original and S+) and PFC groups using the nearest neighbor method for radiographic analysis. Radiographs were assessed to compare the presence of radiolucent lines in the Attune S+, standard Attune, and PFC implants. Results. At a mean of 8.4 years follow-up, 308 implants underwent revision equating to 3.58 revisions per 1000 implant-years. The lowest risk of revision was noted in the ATTUNE cohort with 2.98 per 1000-implant-years where the PFC and All Other Implant groups were 3.15 and 4.4 respectively. Aseptic loosing was the most common cause for revision across all cemented implants with 76% (65/88) of involving loosening of the tibia. Survival analysis comparing the ATTUNE cohort to the PFC and All Other Cemented Implant cohorts showed no significant differences for: all-cause revision, aseptic loosening, or tibial loosening (p=0.15,0.77,0.47). Radiolucent lines were detected in 4.6%, 5.8%, and 5.0% of the ATTUNE S+, standard ATTUNE, and PFC groups respectively. These differences were not significant. Conclusion. This study represents the largest non-registry review of the original and S+ ATTUNE TKR in comparison to its predicate design as well as other cemented implants. There appears to be no significant increased revision rate for all-cause revision or aseptic loosening. Radiographic analysis also showed no significant difference in peri-implant radiolucency. It appears that concerns of early loosening may be unfounded. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Knee osteoarthritis (KOA) diagnosis is based on symptoms, assessed through questionnaires such as the WOMAC. However, the inconsistency of pain recording and the discrepancy between joint phenotype and symptoms highlight the need for objective biomarkers in KOA diagnosis. To this end, we study relationships among clinical and molecular data in a cohort of women (n=51) with Kellgren-Lawrence grade 2–3 KOA through Support Vector Machine (SVM) and a regulation network model (RNM). Clinical descriptors (i.e., pain catastrophism (CA); depression (DE); functionality (FU); joint pain (JP); rigidity (RI); sensitization (SE); synovitis (SY)) are used to classify patients. A Youden's test is performed for each classifier to determine optimal binarization thresholds for the descriptors. Thresholds are tested against patient stratification according to baseline WOMAC data from the Osteoarthritis Initiative, and the mean accuracy is 0.97. For our cohort, the data used as SVM inputs are KOA descriptors, synovial fluid (SL) proteomic measurements (n=25), and transcription factors (TF) activation obtained from RNM [2] stimulated with the SL measurements. The relative weights after classification reflect input importance. The performance of each classifier is evaluated through AUC-ROC analysis. The best classifier with clinical data is CA (AUC = 0.9), highly influenced by FU and SE, suggesting that kinesophobia is involved in pain perception. With SL input, leptin strongly influences every classifier, suggesting the importance of low-grade inflammation. When TF are used, the mean AUC is limited to 0.608, which can be related to the pleomorphic behaviour of osteoarthritic chondrocytes. Nevertheless, FU has an AUC of 0.7 with strong importance of FOXO downregulation. Though larger and longitudinal cohorts are needed, this unique combination of SVM and RNM shall help to map objectively KOA descriptors. Acknowledgements: Catalan & Spanish governments 2020FI_b00680; STRATO-PID2021126469ob-C21-2, European Commission (MSCA-TN-ETN-2020-Disc4All-955735, ERC-2021-CoG-O-Health-101044828). ICREA Academia

Total knee arthroplasty (TKA) aims to alleviate pain and restore joint biomechanics to an equivalent degree to age-matched peers. Zimmer Biomet's Nexgen TKA was the most common implant in the UK between 2003 and 2016. This study compared the biomechanical outcomes of the Nexgen implant against a cohort of healthy older adults to determine whether knee biomechanics is restored post-TKA. Patients with a primary Nexgen TKA and healthy adults >55 years old with no musculoskeletal deficits or diagnosis of arthritis were recruited locally. Eligible participants attended one research appointment. Bilateral knee range of motion (RoM) was assessed with a goniometer. A motorised arthrometer (GENOUROB) was then used to quantify the anterior-posterior laxity of each knee. Finally, gait patterns were analysed on a treadmill. An 8-camera Vicon motion capture system generated the biomechanical model. Preliminary statistical analyses were performed in SPSS (α = 0.05; required sample size for ongoing study: n=21 per group). The patient cohort (n=21) was older and had a greater BMI than the comparative group (n=13). Patients also had significantly poorer RoM than healthy older adults. However, there were no inter-group differences in knee laxity, walking speed or cadence. Gait kinematics were comparable in the sagittal plane during stance phase. Peak knee flexion during swing phase was lower in the patient group, however (49.0° vs 41.1°). Preliminary results suggest that knee laxity and some spatiotemporal and kinematic parameters of gait are restored in Nexgen TKA patients. While knee RoM remains significantly poorer in the patient cohort, an average RoM of >110° was achieved. This suggests the implant provides sufficient RoM for most activities of daily living. Further improvements to knee kinematics may necessitate additional rehabilitation. Future recruitment drives will concentrate on adults over the age of 70 for improved inter-group comparability

A hot swollen joint is a commonly encountered condition in clinical practice. With a broad range of differentials, septic arthritis (SA) is perhaps one of the most concerning. Treated by culture-specific antibiotics and arthroscopic lavage, some patients require multiple washouts. We aimed to determine:. (1) What are the risk factors for development of SA?. (2) What are the risk factors for repeat washout in SA patients?. (3) What are the important clinical differences between a periprosthetic joint infection (PJI) and SA cohort?. All patients presenting to the emergency department, orthopaedic, and rheumatology clinics between January 2020 to January 2021 with a hot, swollen joint were retrospectively evaluated. Patients with previous trauma on the ipsilateral joint, with data missing from their medical records in any of the variables required for analysis, <24 months follow-up were excluded. Variables of interest in the three-month period preceding the diagnosis of SA were compared between SA and non-SA patients. Factors with a p-value of p<0.100 in univariate analysis were included in a stepwise multivariate logistic regression model. Similar analyses were performed to compare SA patients with multiple washouts with those needing one washout. Demographical and clinical data for PJI patients were collected to delineate important differences with SA cohort. 211 patients were included (SA:28;PJI:24;pseudogout:32;gout:26;others:101). Multivariate analysis showed rheumatoid arthritis (RA), skin infection, and liver disease were risk factors for SA. Amongst patients with septic arthritis, multivariate analysis showed that WBC levels above normal limits (3.6-10.5×109 cells/L) and RA were risk factors for multiple washouts. Between the SA and PJI cohorts, BMI (p=0.002) was significantly lower in the former, whilst WBC level (p=0.023) and CRP (p<0.0001) was significantly higher in the former. Early diagnosis of septic arthritis requires understanding the risk factors, namely RA, skin infection, and liver disease. Considering PJI and septic arthritis as the same entity can lead to wrong clinical judgement, and clinicians should be aware of important differences. We believe that the models in this study are of prognostic value to clinicians who are presented with the common presenting compliant of a hot swollen joint

Fragility ankle fractures are traditionally managed conservatively or with open reduction internal fixation (ORIF). Tibiotalocalcaneal (TTC) fusion is an alternative option for the geriatric patient. This systematic review and meta-analysis provides a detailed analysis of the functional and clinical outcomes of hindfoot nailing for fragility ankle fractures presented so far in the literature. A systematic search was performed on MEDLINE, EMBASE, Cochrane Library, Scopus, Web of Science, identifying fourteen studies for inclusion. Studies including patients over 60 with a fragility ankle fracture, treated with TTC nail were included. Patients with a previous fracture of the ipsilateral limb, fibular nails, and pathological fractures were excluded. Subgroup analyses were performed according to (1) open vs closed fractures, (2) immediate post-operative FWB vs post-operative NWB, (3) majority of cohort are diabetics vs minority of cohort are diabetics. Meta-regression analyses were done to explore sources of heterogeneity, and publication bias was assessed using Egger's test. The pooled proportion of superficial infection, deep infection, implant failure, malunion, and all-cause mortality was 0.10 (95%CI:0.06-0.16; I2=44%), 0.08 (95%CI:0.06-0.11, I2=0%), 0.11 (95%CI:0.07-0.15, I2=0%), 0.11 (95%CI:0.06-0.18; I2=51%), and 0.27 (95%CI:0.20-0.34; I2=11%), respectively. The pooled mean post-operative OMAS score was 54.07 (95%CI:48.98-59.16; I2=85%). The best-fitting meta-regression model included age and percentage of male patients as covariates (p=0.0263), and were inversely correlated with higher OMAS scores. Subgroup analyses showed that studies with a majority of diabetics had a higher proportion of implant failure (p=0.0340) and surgical infection (p=0.0096), and a lower chance of returning to pre-injury mobility than studies with a minority of diabetics (p=0.0385). Egger's test (p=0.56) showed no significant publication bias. TTC nailing is an adequate alternative option for fragility ankle fractures. However, current evidence includes mainly case series with inconsistent outcome measures reported and post-operative rehabilitation protocols. Prospective RCTs with long follow-up times and large cohort sizes are needed to clearly guide the use of TTC nailing for ankle fractures

Abstract. Objectives. Exploring the relationship of gait function pre and post total knee replacement (TKR) in two groups of patients. Methods. Three-dimensional gait analysis was performed at Cardiff University, UK, and Karolinska University Hospital, Sweden, on 29 and 25 non-pathological (NP) volunteers, and 39 and 28 patients with end-stage knee osteoarthritis (OA), respectively. Patients were assessed pre and one-year post-TKR. Data reduction was performed via Principal Component (PC) analysis on twenty-four kinematic and kinetic waveforms in both NP and pre/post-TKR. Cardiff's and Karolinska's cohorts were analysed separately. The Cardiff Classifier, a classification system based on the Dempster-Shafer theory, was trained with the first 3 PCs of each variable for each cohort. The Classifier classifies each participant by assigning them a belief in NP, belief in OA (BOA) and belief in uncertainty, based on their biomechanical features. The correlation between patient's BOA values (range: 0–1, 0 indicates null BOA and 1 high BOA) pre and post-TKR was tested through Spearman's correlation coefficient in each cohort. The related-samples Wilcoxon signed-rank test (α=0.05) determined the significant changes in BOA in each cohort of patients. The Mann-Whitney U test (α=0.05) was run to explore differences between the patients’ cohorts. Results. There were no significant differences between patients’ cohorts in median age (p=0.096), height (p=0.673), weight (p=0.064) or KOOS sub-scores pre or post-TKR (p-value ranged 0.069 to 0.955) but Cardiff's patients had a significantly higher BMI (p=0.047). There was a significant, median decrease of 0.12 and 0.19 in the BOA pre to post TKR (p<0.001) in Cardiff's and Karolinska's patients, respectively. There was a statistically significant, strong positive correlation between the BOA pre and post-TKR (Cardiff:r. s. =0.706, p<0.001; Karolinska:r. s. =0.669, p<0.001). Conclusions. In two distinct cohorts of patients, having a more compromised gait function in end-stage knee OA was correlated with poorer gait function post-TKR

Adult Spine Deformity (ASD) is a degenerative condition of the adult spine leading to altered spine curvatures and mechanical balance. Computational approaches, like Finite Element (FE) Models have been proposed to explore the etiology or the treatment of ASD, through biomechanical simulations. However, while the personalization of the models is a cornerstone, personalized FE models are cumbersome to generate. To cover this need, we share a virtual cohort of 16807 thoracolumbar spine FE models with different spine morphologies, presented in an online user-interface platform (SpineView). To generate these models, EOS images are used, and 3D surface spine models are reconstructed. Then, a Statistical Shape Model (SSM), is built, to further adapt a FE structured mesh template for both the bone and the soft tissues of the spine, through mesh morphing. Eventually, the SSM deformation fields allow the personalization of the mean structured FE model, leading to generate FE meshes of thoracolumbar spines with different morphologies. Models can be selectively viewed and downloaded through SpineView, according to personalized user requests of specific morphologies characterized by the geometrical parameters: Pelvic Incidence; Pelvic Tilt; Sacral Slope; Lumbar Lordosis; Global Tilt; Cobb Angle; and GAP score. Data quality is assessed using visual aids, correlation analyses, heatmaps, network graphs, Anova and t-tests, and kernel density plots to compare spinopelvic parameter distributions and identify similarities and differences. Mesh quality and ranges of motion have been assessed to evaluate the quality of the FE models. This functional repository is unique to generate virtual patient cohorts in ASD. Acknowledgements: European Commission (MSCA-TN-ETN-2020-Disc4All-955735, ERC-2021-CoG-O-Health-101044828)

Elective orthopaedic procedures, and particularly total hip arthroplasty (THA), in octogenarians and nonagenarians patients are burdened of several implications. Besides the comorbidities and the anesthesiological issues, legal and ethical implications are present. Some literature data show the clinical improvement of THA in elderly patient but the psychological aspects are not yet evaluated. Aim of this study is to evaluate the clinical aspects and the psychological impact in daily living in octogenarians and nonagenarians patients addressing THA. We conducted a retrospective evaluation of 81 THA in 81 patients of age more than 85 years with a minimum follow-up of 6 months. Clinical aspects were evaluated using the Hip disability and Osteoarthritis Outcome Score (HOOS). The psychological issues were evaluated with the Short Form 12 (SF-12) using both the Physical Component Summary (PCS) and the Mental Component Summary (MCS). From the starter cohort of 81 patients, 8 patients were died for causes unrelated to surgery, 13 were lost to follow-up, 1 patient was revised for periprosthetic fracture; 59 patients composed the final cohort. Mean HOOS rased from 18,07 ± 17,81 to 92,36 ± 5,74 with statistically significant distribution both in the global score than in all of the different subscales. The PCS raised from 26,81 ± 10,81 to 51,86 ± 4,45 and The MCS raised from 34,84 ± 10,81 to 56,70 ± 5,04, but none of them showed a statistically significant distribution. THA in octogenarians and nonagenarians patients could be a safe procedure with positive results for clinical and psychological aspects

Septic arthritis following anterior cruciate ligament reconstruction (ACLR) is a rare and serious complication. Previous studies have shown that septic arthritis is associated with inferior outcome of ACLR. Despite that, there is no standardized treatment protocol, and the course of the disease has mainly been studied within single institutions with a small number of patients. The aim of the present study is to describe the course of septic arthritis following ACLR in a large nationwide cohort. The hypothesis was that the clinical presentation of septic arthritis following ACLR varies according to the infectious agent. The present cohort represents patients with septic arthritis identified in a previous study that analyzed compensation claims reported to the Swedish national insurance company (Löf) in 2005–2014 (1). The diagnosis was confirmed by medical experts at Löf after review of medical records. We conducted a comprehensive analysis of the medical records as well as data available from the Swedish National Knee Ligament Registry (SNKLR) for the study group. The study involved 158 patients who received compensation due to developing septic arhtirits. 94 (59.9%) patients were infected with Coagulase negative staphylococci (CoNS), and 25 patients by Staphyolococcus Aureus (S.Aureus) (15.9%). There was a significant difference between the groups regarding Maximum CRP (p<0.001), and duration between ACLR and first washout operation (p<0.005). S.aureus group had the higest maximum CRP (281) and the shortest duration between ACLR and first washout operation (12 days). The Clinical presentation of septic arthritis following ACLR can vary according to the agent causing the infection, and low virulent agents are responsible for the majority of the infections. Clinicians need to be aware of these differences and consider them when making diagnosis or treatment decisions