Aims

The paediatric trigger thumb is a distinct clinical entity with unique anatomical abnormalities. The aim of this study was to present the long-term outcomes of A1 pulley release in idiopathic paediatric trigger thumbs based on established patient-reported outcome measures.

This study compared the pullout forces of the initial implantation and the “cement-in-cement” revision technique for short and standard-length (125 mm vs. 150 mm) Exeter. ®. V40 femoral stems used in total hip arthroplasty (THA). The idea that the pullout force for a double taper slip stem is relative to the force applied to the femur and that “cement-in-cement” revision provides the same reproduction of force. A total sample size of 15 femoral stems were tested (Short, n = 6 and Standard, n = 9). 3D printed fixtures for repeatable sample preparation were used to minimize variance during testing. To promote stem subsidence and to simulate an in vivo environment, the samples were placed in an incubator at 37°C at 100% humidity and experienced a constant compressive loading of 1335 N for 14 days. The samples underwent a displacement-controlled pullout test. After the initial pullout test, “cement-in-cement” revision will be performed and tested similar to the initial implantation to observe the efficacy of the revision technique. To compare the pullout forces between the two groups, a Kruskal-Wallis test using a significance level of 0.05 was conducted. The mean maximum pullout force for the short and standard-length femoral stems were 3939 ± 1178 N and 5078 ± 1168 N, respectively. The Kruskal-Wallis test determined no statistically significant difference between the two groups for the initial implantation (p = 0.13). The “cement-in-cement” revision pullout force will be conducted in future testing. This study demonstrated the potential use of short stem designs for THA as it provides similar levels of fixation as the standard-length femoral stem. The potential benefits for using a short stem design would be providing similar load transfer to the proximal femur, preserving proximal metaphyseal femoral bone in primary replacement, and reducing the invasiveness during revision

For all the research into arthroplasty, provision of total knee arthroplasty (TKR) services based on gender in the Australian context is yet to be explored. International literature points toward a heavily gender biased provision of TKA services, skewed away from female patients. This research has aimed to assess the current experience of Australian female patients and to explore better assessment techniques that could provide more equitable services. A retrospective cohort analysis has been conducted using pre-op PROMs data, where available, from the Australian National Joint Replacement Registry (AOANJRR), between 7 August 2018 and 31 December 2021, including: EQ VAS Health; Oxford Knee Score; joint pain; and KOOS-12. Data was adjusted for age, ASA score, BMI, primary diagnosis, public vs private hospital, surgeon gender and years of practice (as estimated from years of registry data available). Of 1,001,231 procedures performed, 27,431 were able to be analysed (12,300 male and 15,131 female). Gender-based bias against female patients reached statistical significance across all PROM scores, according to the Kruskal-Wallis test of difference (p-value <0.0001). Males were more likely to undergo TKR than females, with odds ratios remaining statistically significant when adjusted for age, ASA score, BMI, primary diagnosis, and hospital type. Numbers were further analysed for surgeon years of recorded practice and surgeon gender with mixed results. This study found that women were less likely to undergo TKR despite worse scores on every pre-op PROM available, thus we demonstrate a statistically significant gender-based bias against female patients. More effort needs to be made to identify the base of this bias and find new ways to assess patients that can provide more equitable provision of healthcare

Aims. This study aimed to evaluate the association between the sagittal alignment of the femoral component in total knee arthroplasty (TKA) and new Knee Society Score (2011KSS), under the hypothesis that outliers such as the excessive extended or flexed femoral component were related to worse clinical outcomes. Methods. A group of 156 knees (134 F:22 M) in 133 patients with a mean age 75.8 years (SD 6.4) who underwent TKA with the cruciate-substituting Bi-Surface Knee prosthesis were retrospectively enrolled. On lateral radiographs, γ angle (the angle between the distal femoral axis and the line perpendicular to the distal rear surface of the femoral component) was measured, and the patients were divided into four groups according to the γ angle. The 2011KSSs among groups were compared using the Kruskal-Wallis test. A secondary regression analysis was used to investigate the association between the 2011KSS and γ angle. Results. According to the mean and SD of γ angle (γ, 4.0 SD 3.0°), four groups (Extended or minor flexed group, −0.5° ≤ γ < 2.5° (n = 54)), Mild flexed group (2.5° ≤ γ < 5.5° (n = 63)), Moderate flexed group (5.5° ≤ γ < 8.5° (n = 26)), and Excessive flexed group (8.5° ≤ γ (n = 13)) were defined. The Excessive flexed group showed worse 2011KSSs in all subdomains (Symptoms, Satisfaction, Expectations, and Functional activities) than the Mild flexed group. Secondary regression showed a convex upward function, and the scores were highest at γ = 3.0°, 4.0°, and 3.0° in Satisfaction, Expectations, and Functional activities, respectively. Conclusion. The groups with a sagittal alignment of the femoral component > 8.5° showed inferior clinical outcomes in 2011KSSs. Secondary regression analyses showed that mild flexion of the femoral component was associated with the highest score. When implanting the Bi-Surface Knee prosthesis surgeons should pay careful attention to avoiding flexing the femoral component extensively during TKA. Our findings may be applicable to other implant designs. Cite this article: Bone Joint J 2020;102-B(6 Supple A):36–42

Aims. The aim of this retrospective study was to determine if there are differences in short-term clinical outcomes among four different types of matrix-associated autologous chondrocyte transplantation (MACT). Methods. A total of 88 patients (mean age 34 years (SD 10.03), mean BMI 25 kg/m. 2. (SD 3.51)) with full-thickness chondral lesions of the tibiofemoral joint who underwent MACT were included in this study. Clinical examinations were performed preoperatively and 24 months after transplantation. Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC) Subjective Knee Form, the Brittberg score, the Tegner Activity Scale, and the visual analogue scale (VAS) for pain. The Kruskal-Wallis test by ranks was used to compare the clinical scores of the different transplant types. Results. The mean defect size of the tibiofemoral joint compartment was 4.28 cm. 2. (SD 1.70). In total, 11 patients (12.6%) underwent transplantation with Chondro-Gide (matrix-associated autologous chondrocyte implantation (MACI)), 40 patients (46.0%) with Hyalograft C (HYAFF), 21 patients (24.1%) with Cartilage Regeneration System (CaReS), and 15 patients (17.2%) with NOVOCART 3D. The mean IKDC Subjective Knee Form score improved from 35.71 (SD 6.44) preoperatively to 75.26 (SD 18.36) after 24 months postoperatively in the Hyalograft group, from 35.94 (SD 10.29) to 71.57 (SD 16.31) in the Chondro-Gide (MACI) group, from 37.06 (SD 5.42) to 71.49 (SD 6.76) in the NOVOCART 3D group, and from 45.05 (SD 15.83) to 70.33 (SD 19.65) in the CaReS group. Similar improvements were observed in the VAS and Brittberg scores. Conclusion. Two years postoperatively, there were no significant differences in terms of outcomes. Our data demonstrated that MACT, regardless of the implants used, resulted in good clinical improvement two years after transplantation for localized tibiofemoral defects. Cite this article: Bone Joint Res 2021;10(7):370–379

Aims. The adequate provision of personal protective equipment (PPE) for healthcare workers has come under considerable scrutiny during the COVID-19 pandemic. This study aimed to evaluate staff awareness of PPE guidance, perceptions of PPE measures, and concerns regarding PPE use while caring for COVID-19 patients. In addition, responses of doctors, nurses, and other healthcare professionals (OHCPs) were compared. Methods. The inclusion criteria were all staff working in clinical areas of the hospital. Staff were invited to take part using a link to an online questionnaire advertised by email, posters displayed in clinical areas, and social media. Questions grouped into the three key themes - staff awareness, perceptions, and concerns - were answered using a five-point Likert scale. The Kruskal-Wallis test was used to compare results across all three groups of staff. Results. Overall, 315 staff took part in our study. There was a high awareness of PPE guidance at 84.4%, but only 52.4% of staff reported adequate PPE provision. 67.9% were still keen to come to work, despite very high levels of anxiety relating to contracting COVID-19 despite wearing PPE. Doctors had significantly higher ratings for questions relating to PPE awareness compared to other staff groups, while nursing staff and OHCPs had significantly higher levels of anxiety compared to doctors in relation to PPE and contracting COVID-19 (p < 0.05 using a Kruskal-Wallis test). Conclusion. We believe four recommendations are key to improve PPE measures and decrease anxiety: 1) nominated ward/department PPE champions; 2) anonymized reporting for PPE concerns; 3) formal PPE education sessions; and 4) drop-in counselling sessions for staff. We hope the insight and recommendations from this study can improve the PPE situation and maintain the health and wellbeing of the clinical work force, in order to care for COVID-19 patients safely and effectively

Abstract. OBJECTIVES. To determine if force measured using a strain gauge in circular external fixation frames is different for 1) different simulated stages of bone healing, and for 2) fractures clinically deemed either united or un-united. METHODS. In a laboratory study, 3 similar Ilizarov frame constructs were assembled using a Perspex bone analogue. Constructs were tested in 10 different clinical situations simulating different stages of bone healing including with the bone analogue intact, with 1,3 and 50mm gaps, and with 6 materials of varying stiffness's within the 50mm gap. A Bluetooth strain gauge was inserted across the simulated fracture focus, replacing one of the 4 threaded rods used to construct the frame. Constructs were loaded to 700N using an Instron testing machine and maximum force during loading was measured by the strain gauge. Testing was repeated with the strain gauge replacing each of the 4 threaded rods in turn, with measurements being repeated 3 times, across all 3 frame constructs for all 10 simulated clinical situations (n=360). Force measurements between the situations were compared using a Kruskal-Wallis test (KW) and a post-hoc Steel test was used for multiple comparison against control (intact bone model). Additionally, a pilot study has been initiated to assess clinical efficacy of the strain gauge measurement in patients with circular frames. The strain gauge replaced the anterior rod across the fracture focus for each patient. Patients were asked to step on a weighing scale with their affected limb, and maximum weight transfer through the limb and maximal force measured in the frame were recorded. This was repeated 3 times and a mean ratio of force to weight through affected limb was calculated for each patient. The clinical situation at each measurement was designated as united or un-united by one of the senior authors for analysis. Force measurements between the situations were compared using a Wilcoxon-Mann-Whitney test. RESULTS. In the laboratory study, including all constructs with the strain gauge in all positions, a statistically significant relationship between model stability and force measured was identified (KW test for overall relationship p<0.0001). The largest force was measured in the model with a 50mm gap (median 170N, IQR 155–192, range 83–213) and the smallest in the intact bone model (median 3N, IQR 1–8, range 0–11). Multiple comparison testing found a significant difference between intact bone and all the unstable situations (p=0.002 or better). Examining initial results from our pilot clinical study, nine measurements were available in seven patients. Three of these were taken in patients with fractures yet to unite, six in patients where union has since been confirmed clinically. The median force measured was significantly greater where the fracture was not united (median 1.66 N/kg, range 1.07–1.99 vs 0.12 N/kg, range 0.05–0.73, p=0.02). CONCLUSIONS. This laboratory study demonstrates that force measurement may be different at different stages of healing, and although only limited data was available, a pilot clinical study showed a significant relationship between the force measured and clinical union of the patient's fracture. 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

A growing number of recent investigations on the human genome, gut microbiome, and proteomics suggests that the loss of mucosal barrier function, particularly in the gastrointestinal tract, may substantially affect antigen trafficking, ultimately influencing the close bidirectional interaction between the gut microbiome and the immune system. This cross-talk is highly influential in shaping the host immune system and ultimately clinical infections. The hypothesis of the current study was that a change in microbiome and/or breach in GI epithelial barrier could be partially responsible for development of periprosthetic joint infections (PJI). Multiple biomarkers of gut barrier disruption were tested in parallel in plasma samples collected as part of a prospective cohort study of patients undergoing revision arthroplasty for aseptic failures or PJI (As defined by the 2018 ICM criteria). All blood samples were collected before any antibiotic was administered. Samples were tested for Zonulin, soluble CD14 (sCD14), and lipopolysaccharide (LPS) using commercially available enzyme-linked immunosorbent assays. Statistical analysis consisted of descriptive statistics, Mann-Whitney t-test, and Kruskal-Wallis test. A total of 134 patients were consented and included in the study. 44 were classified as PJI (30 chronic and 14 acute), and 90 as aseptic failures (26 primaries and 64 aseptic revisions). Both Zonulin and sCD14, but not LPS, were found to be significantly increased in the PJI group compared to non-infected cases (p<0.001; p=0.003). Higher levels of Zonulin were found in acute infections compared to chronic PJI (p=0.005. This prospective ongoing study reveals a possible link between gut permeability and the ‘gut-immune-joint axis’ in PJI. If this association continues to be born out with larger cohort recruitment and more in-depth analysis, it would have an immense implication in managing patients with PJI. In addition to administering antimicrobials, patients with PJI and other orthopedic infections may require gastrointestinal modulators such as pro and prebiotics

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

Abstract. Objectives. Oil-based fluids can be used to enhance the properties of polyethylene materials. For example, vitamin E infused polyethylene has a superior oxidation resistance and Lipiodol infused polyethylene has an enhanced X-ray attenuation. The aim of this study was to evaluate the long-term influence of oily fluid on the chemical, physical and tensile properties of polyethylene. Methods. An accelerated ageing procedure (an elevated temperature (80. °. C) for four weeks in air. 1. ) was used to investigate the oxidative stability (ASTM F2012-17). 2. , tensile (ISO 527). 3. and thermal properties. 4. of oil treated polyethylene (n=5, GUR 1050, Celanese, Germany)and compared with clinically used polyethylene controls (oil-free standard and thermally treated polyethylene). All the experiments were performed on aged and unaged specimens in accordance to international standards and compared to currently available literature. A Kruskal-Wallis test was performed using a custom MATLAB code (R2017a, USA); with p < 0.05 considered statistically significant. Results. Samples treated with an oil (Vitamin E or Lipiodol) had a higher oxidation stability than currently used medical grade polyethylene, indicated by a smaller increase in oxidation index after ageing (Vitamin E 36%, Lipiodol 40%, untreated 136 %, thermally treated 164%). The mechanical degradation of oil treated polyethylene was also less significant than the untreated controls, as all the tensile properties of oil treated polyethylene after ageing were significantly higher than the standard controls (p>0.05). There was also no alteration in the percentage crystallinity of oil treated samples after ageing. Conclusion. The result of this study indicate that the presence of an oily fluid in polyethylene does not reduce its oxidative stability or tensile properties, providing improved material properties for long term implant applications. 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

Introduction and Objective. Anterior cruciate ligament reconstruction (ACLR) with tendon autografts is the “gold standard” technique for surgical treatment of ACL injuries. Common tendon graft choices include patellar tendon (PT), semitendinosus/gracilis “hamstring” tendon (HT), or quadriceps tendon (QT). Healing of the graft after ACLR may be affected by graft type since the tissue is subjected to mechanical stresses during post-operative rehabilitation that play important roles in graft integration, remodeling and maturation. Abnormal mechanical loading can result in high inflammatory and degradative processes and altered extracellular matrix (ECM) synthesis and remodeling, potentially modifying tissue structure, composition, and function. Because of the importance of load and ligamentization for tendon autografts, this study was designed to compare the differential inflammatory and degradative metabolic responses to loading by three tendon types commonly used for autograft ACL reconstruction. Materials and Methods. With IRB approval (IRB # 2009879) and informed patient consent, portions of 9 QT, 7 PT and 6 HT were recovered at the time of standard of care ACLR surgeries. Tissues were minced and digested in 0.2 mg/ml collagenase solution for two hours and were then cultured in 10% FBS at 5% CO. 2. , 37°C, and 95% humidity. Once confluent, cells were plated in Collagen Type I-coated BioFlex® plates (1 × 10. 5. cells/well) and cultured for 2 days prior to the application of strain. Then, media was changed to supplemented DMEM with 2% FBS for the application of strain. Fibroblasts were subjected to continuous mechanical stimulation (2-s strain and 10-s relaxation at a 0.5 Hz frequency) at three different elongation strains (mechanical stress deprivation-0%, physiologic strain-4%, and supraphysiological strain-10%). 9. for 6 days using the Flexcell FX-4000T strain system. Media was tested for inflammatory biomarkers (PGE2, IL-8, Gro-α, and MCP-1) and degradation biomarkers (GAG content, MMP-1, MMP-2, MMP-3, TIMP-1, and TIMP-2). Significant (p<0.05) difference between graft sources were assessed with Kruskal-Wallis test and post-hoc analysis. Results are reported as median± interquartile range (IQR). Results. Differences in Inflammation-Related Biomarker Production (Figure 1): The production of PGE2 was significantly lower by HT fibroblasts compared to both QT and PT fibroblasts at all timepoints and strain levels. The production of Gro-α was significantly lower by HT fibroblasts compared to QT at all time points and strain levels, and significantly lower than PT on day 3 at 0% strain, and all strain levels on day 6. The production of IL-8 by PT fibroblasts was significantly lower than QT and HT fibroblast on day 3 at 10% strain. Differences in Degradation-Related Biomarker Production (Figure 2): The production of GAG by HT fibroblasts was significantly higher compared to both QT and PT fibroblasts on day 6 at 0% strain. The production of MMP-1 by the QT fibroblasts was significantly higher compared to HT fibroblasts on day 3 of culture at all strain levels, and in the 0% and 10% strain levels on day 6 of culture. The production of MMP-1 by the QT fibroblasts was significantly higher compared to PT fibroblasts at in the 0% and 4% strain groups on day 3 of culture. The production of TIMP-1 by the HT fibroblasts was significantly lower compared to PT fibroblasts on day 3 of culture. Conclusions. The results of this study identify potentially clinically relevant difference in the metabolic responses of tendon graft fibroblasts to strain, suggesting a lower inflammatory response by hamstring tendon fibroblasts and higher degradative response by quadriceps tendon fibroblasts. These responses may influence ACL autograft healing as well as inflammatory mediators of pain in the knee after reconstruction, which may have implications regarding graft choice and design of postoperative rehabilitation protocols for optimizing outcomes for patients undergoing ACL reconstruction. For any figures or tables, please contact the authors directly

Introduction and Objective. In multiple trauma patients, as well as in the healing of isolated fractures (Fx) with heavy bleeding (trauma haemorrhage, TH), complications occur very often. This is particularly evident in elderly patients over 65 years of age. Since these accompanying circumstances strongly influence the clinical course of treatment, the influence of age on bone regeneration after femoral fracture and severe blood loss was investigated in this study. Materials and Methods. 12 young (17–26 weeks) and 12 old (64–72 weeks) male C57BL / 6J mice per group were examined. The fracture group Fx underwent an osteotomy after applying an external fixator. The THFx group also received blood pressure-controlled trauma hemorrhage (35 mmHg for 90 minutes) and reperfusion with Ringer's solution for 30 minutes. The Sham group received only the catheter and one external fixator. μCT scans of the femora were performed in vivo after 2 weeks and ex vivo after 3 weeks. Histological and biomechanical examinations were also carried out. The statistical significance was set at p ≤ 0.05. The non-normally distributed data were analyzed using the Mann-Whitney-U or Kruskal-Wallis test. Results. The histology showed less mineralized bone in the fracture gap in old animals of the Fx (25.41% [1.68%]) and THFx groups (25.50% [4.07%]) compared with the young ones (34.20% [6.36%], p = 0.003; 34.31% [5.12%], p=0.009). Moreover, a severe blood loss lead to more cartilage in both young (6.91% [5.08%]) and old animals (4.17% [1.42%]) compared to animals with only a fracture (2, 45% [1.04%], p=0.004; 2.95% [1.12%], p=0.032). In old animals (11.37 / nm. 2. [17.17 / nm. 2. ]) in contrast the young mice with an isolated fracture (33.6/nm. 2. [8.83/nm. 2. ]) fewer osteoclasts were present (p=0.009). Therefore, the severe blood loss further reduced the number of osteoclasts only in young animals (16.83/nm. 2. [6.07/nm. 2. ]) (p=0.004). In the in vivo μCT, after 2 weeks, a lower volume of bone, cortex and callus was found in old THFx animals (3.14 mm. 3. [0.64 mm. 3. ]); 1.01 mm. 3. [0.04 mm. 3. ]; 2.07 mm. 3. [0.57 mm. 3. ]) compared with the Fx animals (4.29 mm. 3. [0.74 mm. 3. ], p=0.008; 1.18 mm. 3. [0, 25 mm. 3. ], p=0.004; 3.02 mm. 3. [0.77 mm. 3. ], p=0.008) After 3 weeks, the ex vivo μCT scans also showed a reduced callus percentage in old THFx animals (61.18% [13.9 9%]), as well as a low number of trabeculae (1.81 mm. -1. [0.23 mm. -1. ]) compared to animals without blood loss (68.72% [15.71%], p = 0.030; 2.06mm. -1. [0.37mm. -1. ], p=0.041). In the biomechanical test, a reduced elasticity limit of the old THFx mice (7.75 N [3.33 N]) in contrast to the old Fx (10.24 N [3.32 N]) animals was shown (p=0.022). Conclusions. A severe blood loss has a higher negative effect on the healing, morphometry, and biomechanical properties of previously fractured femora in old compared to young individuals

Frailty has been shown to be a risk predictor for peri-operative adverse events (AEs) in patients undergoing various type of spine surgery. However, its relationship with Patient Related Outcome Measures (PROMS) remains unknown. The primary objective of this study was to determine the impact of frailty on PROMS in patients undergoing surgery for thoraco-lumbar degenerative conditions. The secondary objective was to determine the association between frailty and baseline PROMS. This is a retrospective study of a prospective cohort of patients >55 years old who underwent surgery between 2012 and 2018. Patient data and PROMS (EQ-5D, SF-12, ODI, back and leg pain NRS) were extracted from the Canadian Spine Outcomes and Research Network registry for a single academic centre. Frailty was retrospectively calculated using the modified frailty index (mFI) and patient were classified as frail, pre-frail and non-frail. Patient characteristics and outcomes were analyzed using ANOVA or Kruskal-Wallis test for continuous variables and Chi square or Fisher's exact test for proportions. A generalized estimating equations (GEEs) regression model was used to assess the association between patients' baseline frailty status and PROMs measures at three and 12 months. 293 patients were included with a mean age of 67 ± 7 years. Twenty-two percent of the patients (n= 65) were frail, 59 % (n=172) were pre-frail and 19% (n=56) were non-frail. At baseline, the three groups had similar PROMS, except for the PCS which was worse in the frail group (mean difference [95% CI], −4.9 [−8.6;-1.1], p= 0.0083). The improvement in the EQ-5D, PCS, MCS, ODI, back and leg pain NRS scores was not significantly different between the three groups (p> 0.05). The was no difference in the evolution of the PROMS at three and 12 months between the three groups (p> 0.05). Although frailty is a known predictor of AEs, it does not predict worse PROMS after spine surgery in that population. At baseline, non-frail, pre-frail and frail patients have similar PROMS

Introduction: Computer navigation systems allow real time evaluation of knee behaviour intraoperatively. Measurements made by navigation reflect soft tissue balance throughout surgery. We studied three different populations of patients undergoing total knee replacement (TKR) with a CT-free navigation system where the goal was to achieve normal alignment. We compared the initial pathological kinematics in each group with the resultant kinematics after correction. Method: The Orthopilot® was used during TKR for three groups of patients A (n=71), B(n=60) and C(n=43) all with endstage osteoarthritis. Patients in groups A and B had TKR performed by surgeon 1, and group C by surgeon 2. Results: Pre-operatively, the mean mechanical femoral axis and the mean mechanical femoro-tibial (MFT) angle were calculated. The mean mechanical femoral axis for group A was −0.5° varus (−6° to 9°), group B was −0.68° varus(−6° to 6°), and for group C was 2.67° valgus (−12° to 10°). P< 0.0001, using Kruskal-Wallis test. Pre-operatively, the mean MFT angle for group A was −3.75° varus(−15° to 17°), group B was −2.98° varus(−17° to 13°), and for group C was 0.16° valgus(−17° to 25°). P=0.003 using Kruskal-Wallis test. These results show that the initial preoperative kinematics are different for the three different populations. Post-operatively we measured the mean MFT angle in groups A, B and C. In group A, the mean MFT angle was −0.38° varus (−4° to 2°), group B was −0.41° varus(−5° to 2°), and group C was −0.02° varus(−3° to 5°). P=0.7 using the Kruskal-Wallis test. These results show that the post-operative kinematics are similar between the three different populations. Discussion: Populations A and B preoperatively exhibited a mean varus MFT angle (−0.5° and −0.68° respectively), compared with a mean valgus MFT angle for group C(2.67°), which were statistically significantly different. Although different surgeons operated on the 3 groups (surgeon 1 operated on groups A and B, and surgeon 2 operated on group C), post-operative kinematics were within a narrow range (−0.02° to −0.41°) and not statistically different (p=0.7). Conclusion: The Orthopilot® results showed that these populations had different initial pathological kinematics. Despite this, and using different operators we obtained similar post-op results within a narrow range. Computer navigation produces reliable, reproducible results independent of population or operator variables

Objectives. The use of the haptically bounded saw blades in robotic-assisted total knee arthroplasty (RTKA) can potentially help to limit surrounding soft-tissue injuries. However, there are limited data characterizing these injuries for cruciate-retaining (CR) TKA with the use of this technique. The objective of this cadaver study was to compare the extent of soft-tissue damage sustained through a robotic-assisted, haptically guided TKA (RATKA) versus a manual TKA (MTKA) approach. Methods. A total of 12 fresh-frozen pelvis-to-toe cadaver specimens were included. Four surgeons each prepared three RATKA and three MTKA specimens for cruciate-retaining TKAs. A RATKA was performed on one knee and a MTKA on the other. Postoperatively, two additional surgeons assessed and graded damage to 14 key anatomical structures in a blinded manner. Kruskal–Wallis hypothesis tests were performed to assess statistical differences in soft-tissue damage between RATKA and MTKA cases. Results. Significantly less damage occurred to the PCLs in the RATKA versus the MTKA specimens (p < 0.001). RATKA specimens had non-significantly less damage to the deep medial collateral ligaments (p = 0.149), iliotibial bands (p = 0.580), poplitei (p = 0.248), and patellar ligaments (p = 0.317). The remaining anatomical structures had minimal soft-tissue damage in all MTKA and RATKA specimens. Conclusion. The results of this study indicate that less soft-tissue damage may occur when utilizing RATKA compared with MTKA. These findings are likely due to the enhanced preoperative planning with the robotic software, the real-time intraoperative feedback, and the haptically bounded saw blade, all of which may help protect the surrounding soft tissues and ligaments. Cite this article: Bone Joint Res 2019;8:495–501

Introduction. Pseudotumors have been reported following metal-on-metal total hip arthroplasty (THA); however, the natural history and longitudinal imaging findings of pseudotumors have yet to be fully analyzed. Our hypothesis was that pseudotumor size might change over time following metal-on-metal THA. This hypothesis was studied longitudinally using magnetic resonance imaging (MRI). Materials and Methods. Screening for pseudotumors was performed using MRI after large-diameter metal-on-metal THA. Initial MRI was conducted at a mean of 36 months postoperatively. Follow-up MRI was performed at a mean of 20 months after the detection of 24 pseudotumors in 20 asymptomatic patients. Pseudotumors were classified as cystic, solid, and mixed types. Fourteen hips were characterized as cystic type and 10 hips were defined as mixed type. There were three men and 17 women with a mean age of 63 years. Pseudotumor size was determined on MRI by manually outlining the greatest size of the mass. Serum cobalt and chromium ion levels were measured in nine patients with unilateral THA at the time of MRI. Statistical analysis was performed using the Kruskal-Wallis test and chi square test to compare age, gender, BMI, head diameter, cup inclination, cup anteversion, and pseudotumor type among changes of pseudotumor size. We compared the pseudotumor size for the three groups (increase in size, no change, decrease in size) using Kruskal-Wallis test and Mann-Whitney U test. Wilcoxon signed-rank test was used to compare median serum metal ion levels over time. A p value < 0.05 was considered significant. This study was approved by the ethics committee of our institution, and all patients provided informed consent. Results. The mean pseudotumor size changed from 729 mm. 2. to 877 mm. 2. Among the 24 hips, pseudotumors increased in size (Fig. 1) in eight (three cystic and five mixed) and decreased in size in six (four cystic and two mixed). Ten hips showed no changes in size (seven cystic and three mixed). We found no significant differences between changes of pseudotumor size and patient characteristics. The mean initial size of pseudotumor was bigger in pseudotumors with increased in size (1002 ± 309 mm. 2. ) than in those with decreased in size (542 ± 295 mm. 2. , p = 0.020) or no change (622 ± 448 mm. 2. , p = 0.041). The median cobalt ion levels at initial MRI and follow-up MRI were 2.0 µg/L and 1.8 µg/L, respectively. The median chromium ion levels at initial MRI and follow-up MRI were 2.0 µg/L and 3.1 µg/L, respectively. No significant differences were observed between the levels of either metal at initial and subsequent MRI. Conclusions. The present results suggest that pseudotumors frequently change in size in asymptomatic patients, and our hypothesis was verified. The initial size of pseudotumor was bigger in pseudotumors with increased in size than in those with decreased in size or no change. And we might predict that bigger pseudotumors would tend to increase in size

The literature indicates that femoroacetabular impingement (FAI) patients do not return to the level of controls (CTRL) following surgery. The purpose of this study was to compare hip biomechanics during stair climbing tasks in FAI patients before and two years after undergoing corrective surgery against healthy controls (CTRL). A total of 27 participants were included in this study. All participants underwent CT imaging at the local hospital, followed by three-dimensional motion analysis done at the human motion biomechanics laboratory at the local university. Participants who presented a cam deformity >50.5° in the oblique-axial or >60° in the radial planes, respectively, and who had a positive impingement test were placed in the FAI group (n=11, age=34.1±7.4 years, BMI=25.4±2.7 kg/m2). The remaining participants had no cam deformity and negative impingement test and were placed in the CTRL group (n=16, age=33.2±6.4 years, BMI=26.3±3.2 kg/m2). The CTRL group completed the biomechanics protocol once, whereas the FAI group completed the protocol twice, once prior to undergoing corrective surgery for the cam FAI, and the second time at approximately two years following surgery. At the human motion biomechanics laboratory, participants were outfitted with 45 retroreflective markers placed according to the UOMAM marker set. Participants completed five trials of stairs task on a three step instrumented stair case to measure ground reaction forces while 10 Vicon MX-13 cameras recorded the marker trajectories. Data was processed using Nexus software and divided into stair ascent and stair descent tasks. The trials were imported into custom written MatLab software to extract peak pelvis and hip kinematics and hip kinetic variables. Non-parametric Kruskal-Wallis tests were used to determine significant (p < 0.05) differences between the groups. No significant differences occurred during the stair descent task between any of the groups. During the stair ascent task, the CTRL group had significantly greater peak hip flexion angle (Pre-Op=58±7.1°, Post-Op=58.1±6.6°, CTRL=64.1±5.1°) and sagittal hip range of motion (ROM) (Pre-Op=56.7±6.7°, Post-Op=56.3±5.5°, CTRL=61.7±4.2°) than both the pre- and post-operative groups. Pre-operatively, the FAI group had significantly less peak hip adduction angle (Pre-Op=2±4.5°, Post-Op=3.4±4.4°, CTRL=5.5±3.7°) and hip frontal ROM (Pre-Op=9.9±3.4°, Post-Op=11.9±5.4°, CTRL=13.4±2.5°) compared to the CTRL group. No significant differences occurred in the kinetic variables. Our findings are in line with the Rylander and colleagues (2013) who also found that hip sagittal ROM did not improve following corrective surgery. Their study included a mix of cam and pincer-type FAI, and had a mean follow-up of approximately one year. Our cohort included only cam FAI and they had a mean follow-up of approximately two years, indicating with the extra year, the patients still did not show sagittal hip kinematics improvement. In the frontal plane, there was no significant difference between the post-op and the CTRL, indicating that the postoperative FAI reached the level of the CTRLs. This is in line with recent work that indicates a more medialized hip contact force vector following surgery, suggesting better hip stabilization

Introduction. It is well-known that wear debris generated by metal-on-metal hip replacements leads to aseptic loosening. This process starts in the local tissue where an inflammatory reaction is induced, followed by an periprosthetic osteolysis. MOM bearings generate particles as well as ions. The influence of both in human bodies is still the subject of debate. For instance hypersensitivity and high blood metal ion levels are under discussion for systemic reactions or pseudotumors around the hip replacement as a local reaction. The exact biopathologic mechanism is still unknown. The aim of this study was to investigate the impact of local injected metal ions and metal particles. Material and Methods. We used an established murine inflammation model with Balb/c mice and generated three groups. Group PBS (control group, n=10) got an injection of 50µl 0.1 vol% PBS-suspension, Group MI (Metal-ion, n=10) got an injection of 50µl metal ion suspension at a concentration of 200µg/l and Group MP (Metal-particles, n=10) got an injection of 50µl 0.1 vol% metal particle suspension each in the left knee. After incubation for 7 days the mice were euthanized and the extraction of the left knee ensued. Followed by immunhistochemical treatment with markers of inflammation that implied TNFα, IL-6, IL-1β, CD 45, CD 68, CD 3, we counted the positive cells in the synovial layer in the left knees by light microscopy, subdivided into visual fields 200× magnified. The statistical analysis was done with Kruskal-Wallis test and a post hoc Bonferroni correction. Results. The Group with metal particles showed significantly elevated inflammatory markers (TNFα, IL-6, IL-1β, CD 68, CD 45) compared to all other groups. Interestingly, CD 3 as a marker for T-lymphocytes showed no increased levels in all groups. The metal ion group showed significant elevated CD 45 expressions compared to the control group. Conclusion. The results clearly demonstrate that especially metal wear particles lead to an intensive inflammatory reaction. The tissue formations in the metal particle group show an osseous destructive behavior in previously demonstrated results, comparable to pseudotumors. But, in this study, the expression of the immunohistological markers CD 3, CD 45 and CD 68 indicate that the tissue consists of leucocytes and macrophages, whereas lymphocytes could not be detected. This might be due to an acute inflammatory reaction, whereas the adaptive immune response by T-lymphocytes seems not (yet) to be activated. Overall it must be stated that solid metal wear particles are responsible for local inflammatory reactions, whereas it is still unknown whether wear particles corrode in vivo and release a potentially high level of locally toxic metal ions

Healthy cartilage is essential for optimal joint function. Although, articular cartilage defects are highly prevalent in the active population and might hamper joint function, the effect of articular cartilage defects on knee contact forces and pressures is not yet documented. Therefore, the present study compared knee contact forces and pressures between patients with a tibiofemoral cartilage defect and healthy controls. This might provide additional insights in movement adaptations and the role of altered loading in the progression from defect to OA. Experimental gait data was collected in 15 patients with isolated articular cartilage defects (8 medial-affected, 7 lateral-affected) and 19 healthy asymptomatic controls and was processed using a musculoskeletal model to calculate contact forces and pressures. Differences between medial-affected, lateral-affected and controls were evaluated using Kruskal-Wallis tests and individually compared using Mann-Whitney-U tests (alpha <0.05). The lateral-affected group walked significantly slower compared to the healthy controls. No adaptations in the movement pattern that resulted in decreased loading on the injured condyle were observed. Additionally, the location of loading was not significantly affected. The current results suggest that isolated cartilage defects do not induce changes in the knee joint loading pattern. Consequently, the involved condyle will be equally loaded, indicating that a similar amount of force should be distributed over the remaining cartilage surrounding the articular cartilage defect and may cause local degenerative changes in the cartilage. This in combination with inflammatory responses might play a key role in the progression from articular cartilage defect to a more severe OA phenotype

The purpose of this study is to compare 90-day costs and outcomes for primary total hip arthroplasty (THA) patients between a non-obese (BMI 18.5–24.9) versus overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–44.9), and super-obese (45+) cohorts. We conducted a retrospective review of a prospective institutional database of primary THA patients from 2006–2013, including patients with a minimum of three-year follow-up. Thirty-three super-obese patients were identified, and the other five cohorts were randomly selected in a 2:1 ratio (total n = 363). Demographics, 90-day outcomes (costs, reoperations, and readmissions), and outcomes after three years (revisions and change scores for SF12, HHS, and WOMAC) were collected. Costs were determined using unit costs from our institutional administrative data for all in-hospital resource utilization. Comparisons between the non-obese and other groups were made with Kruskal-Wallis tests for non-normal data and chi-square and Fisher's exact test for categorical data. The 90-day costs in the morbidly-obese ($13,134 ± 7,250 mean ± standard deviation, p <0.01) and super-obese ($15,604 ± 6,783, p <0.01) cohorts were statistically significantly greater than the non-obese cohorts ($10,315 ± 1,848). Only the super-obese cohort had statistically greater 90-day reoperation and readmission rates than the non-obese cohort (18.2% vs 0%, p <0.01 and 21.2% vs 4.5%, p=0.02, respectively). In addition, reoperations and septic revisions after 3 years were greater in the super-obese cohort compared to the non-obese cohort 21.2% vs 3.0% (p = 0.01), and 18.2% vs 1.5% (p= 0.01), respectively. There were no other statistical differences between the other cohorts with the non-obese cohort at 90-days or after 3 years. Improvements in SF12, HHS, and WOMAC were comparable in all cohorts. The 90-day costs of a primary total hip arthroplasty for morbidly-obese (BMI 40–44.9) and super-obese (BMI>45) are significantly greater than for non-obese patients, yet these patients have comparable improvements in outcome scores. Health care policies, when based purely on the economic impact of health care delivery, may place morbidly-obese and super-obese patients at risk of losing arthroplasty care, thereby denying them access to the comparable quality of life improvements

Purpose. In patients with multiple trauma delayed fracture healing is often diagnosed, but the pathomechanisms are not well known yet. The purpose of the study is to evaluate the effect of a severe hemorrhagic shock on fracture healing in a murine model. Methods. 10 male C57BL/6N mice per group (Fx, TH, THFx, Sham) and point in time were used. The Fx-group received an osteotomy after implantation of a fixateur extern. The TH-group got a pressure controlled hemorrhagic shock with a mean arterial blood pressure of 35 mmHg over 90 minutes. Resuscitation with 4 times the shed blood volume of Ringer solution was performed. The THFx group got both. Sham-animals received the implantation of a catheter and a fixateur extern but no blood loss or osteotomy. After 1, 2, 3, 4 or 6 weeks the animals were sacrificed. For the biomechanics the bones were analyzed via X-ray, µCT and underwent a 3-point bending test. The nondecalcified histology based on slices of Technovit 9100. The signaling pathway was analyzed via RT. 2. Profiler™ PCR Array Mouse Osteoporosis, Western Blot and Quantikine ELISA for RankL and OPG. Statistical significance was set at p < 0.05. Comparisons between groups were performed using the Mann–Whitney U (Fx vs. THFx) or Kruskal-Wallis Test (other groups). Results. The experiment showed that after 1 week the bones of the Fx- and THFx-mice were macroscopically instable. After 2 weeks the Fx-group showed macroscopically a stable bridging whereas the bones of the THFx-group were partly not stable bridged. 3 weeks after surgery the bones of both groups were stable bridged. Analysis via µCT showed that trauma hemorrhage leads to decreased density of the bone and callus and also to increased share of callus per bone volume after 2 weeks. The 3-point-bending test showed that the maximum bending moment is decreased in the group THFx compared to Fx after 2 weeks. The studies of the histology showed after 2 weeks a decrease in bone and cartilage after trauma-hemorrhage by optical analysis of photographs of the slices. The analyses of the signaling pathway pointed to an involvement of the RankL/Opg and IL6 pathway. Conclusion. A hemorrhagic shock has a negative effect on fracture healing in terms of reduced density of the bone and callus, increased share of callus per bone volume, decreased maximum bending moment, reduced mineralization of the callus and leads to changes in the RankL/Opg and IL6 pathways

Aims

Transcription factor nuclear factor kappa B (NF-κB) plays a major role in the pathogenesis of chronic inflammatory diseases in all organ systems. Despite its importance, NF-κB targeted drug therapy to mitigate chronic inflammation has had limited success in preclinical studies. We hypothesized that sex differences affect the response to NF-κB treatment during chronic inflammation in bone. This study investigated the therapeutic effects of NF-κB decoy oligodeoxynucleotides (ODN) during chronic inflammation in male and female mice.

Background. Administration of Botulinum toxin type A (BTX-A) in patients with spastic cerebral palsy aims to improve mobility by increasing joint range of motion and decreasing passive resistance. However, our recent animal experiments indicated that BTX-A can decrease muscle”s length range of force exertion (Lrange), and increase its passive forces and extracellular matrix (ECM) collagen content. Moreover, BTX-A injected into the tibialis anterior (TA) was shown to spread into non-injected synergistic muscles in the whole anterior crural compartment. These effects that contradict the treatment aims deserve further investigation. Aim. To test in a rat model if: (1) BTX-A injected into the medial and lateral gastrocnemius (GM&GL) muscles spreads into the synergistic soleus (SOL) as well as antagonistic TA and extensor digitorum longus (EDL). (2) The muscles exposed show a wider Lrange, decreased muscle passive force and reduced ECM collagen. Methods. 2×0.1U/20µl of BTX-A (BTX-A group, n=6) or only 2×20µl of saline (Control group, n=6) were prepared and each was injected into the mid-belly of the GM and GL separately. 5 days post injection, forces of all muscles were measured in passive state and also on activation. The GM&GL length was changed whereas; all other muscles were kept at constant length. After biomechanical testing, the muscles were histologically analyzed using Gomori trichrome stain to detect ECM collagen. Two-way ANOVA (factors: GM&GL length and animal group) was used to assess BTX-A effects on forces, and the Kruskal-Wallis test was used to test the change in proportion of collagenous tissue for each muscle. Differences were considered significant at p<0.05. Results. Injected muscles: ANOVA showed significant main effects of both factors on GM&GL total forces and a significant interaction. Force reductions are more pronounced at shorter lengths (increase from 80.8% to 88.4% with decreasing length). Lrange decreased (by 24.1%). ANOVA showed significant main effects of only muscle length on GM&GL passive forces and no significant interaction. Non-injected muscles: ANOVA showed significant main effects of both factors (for SOL), or only of BTX-A (for TA and EDL) only on muscle total forces, but no significant interaction. Force drops for the SOL (89.8%) and anterior crural muscles (57.0% and 51.0% for TA and EDL) do indicate spread of BTX-A intra- and extra-compartmentally. Histological analyses showed increased ECM collagen contents of BTX-A group for the GM&GL, TA, and EDL. Conclusion. Narrowed Lrange and increased ECM collagen content are not in accord with the clinical purpose of the treatment. BTX-A did not reduce passive forces, but did not cause an increase either. Remarkably, the results show that BTX-A leakage is a major issue that can affect muscles of even antagonistic muscle compartments. Hence, our animal experiments indicate much more complex BTX-A effects than considered, which requires further testing in patients

Aims

Continuous local antibiotic perfusion (CLAP) has recently attracted attention as a new drug delivery system for orthopaedic infections. CLAP is a direct continuous infusion of high-concentration gentamicin (1,200 μg/ml) into the bone marrow. As it is a new system, its influence on the bone marrow is unknown. This study aimed to examine the effects of high-concentration antibiotics on human bone tissue-derived cells.

Aims

The overall aim of this study was to determine the impact of deprivation with regard to quality of life, demographics, joint-specific function, attendances for unscheduled care, opioid and antidepressant use, having surgery elsewhere, and waiting times for surgery on patients awaiting total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Aims

The aim of this study was to report health-related quality of life (HRQoL) and joint-specific function in patients waiting for total hip or knee arthroplasty surgery (THA or TKA) in Northern Ireland, compared to published literature and a matched normal population. Secondary aims were to report emergency department (ED) and out-of-hours general practitioner (OOH GP) visits, new prescriptions of strong opioids, and new prescriptions of antidepressants while waiting.

Aims

Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI).

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The purpose of this study was to determine the association between prior sleeve gastrectomy in patients undergoing primary total hip and knee arthroplasty, and 90-day complications, incidence of revision arthroplasty, and patient-reported outcome scores at final follow-up.

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The aim of this study was to investigate the outcomes of arthroscopic decompression of calcific tendinitis performed without repairing the rotator cuff defect.

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This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS).

Aims

The primary aim of this study was to determine the ten-year outcome following surgical treatment for femoroacetabular impingement (FAI). We assessed whether the evolution of practice from open to arthroscopic techniques influenced outcomes and tested whether any patient, radiological, or surgical factors were associated with outcome.

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Periprosthetic fractures (PPFs) following hip arthroplasty are complex injuries. This study evaluates patient demographic characteristics, management, outcomes, and risk factors associated with PPF subtypes over a decade.

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Cemented hemiarthroplasty is an effective form of treatment for most patients with an intracapsular fracture of the hip. However, it remains unclear whether there are subgroups of patients who may benefit from the alternative operation of a modern uncemented hemiarthroplasty – the aim of this study was to investigate this issue. Knowledge about the heterogeneity of treatment effects is important for surgeons in order to target operations towards specific subgroups who would benefit the most.

Lubricin is a proteoglycan that is a boundary lubricant in synovial joints and both a surface and collagen inter-fascicular lubricant in ligaments. The purpose of this study was to characterise the mRNA levels for lubricin in the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL) in aging and surgically-induced menopausal rabbits. We hypothesised that lubricin mRNA levels would be increased in ligaments from aging and menopausal rabbits compared with ligaments from normal rabbits. All four knee ligaments (ACL, PCL, MCL, LCL) were isolated from normal (1-year-old rabbits, n=8), aging (3-year-old rabbits, n=6), and menopausal (1-year-old rabbits fourteen weeks after surgical ovariohysterectomy, n=8) female New Zealand White rabbits. RT-qPCR was used to evaluate the mRNA levels for lubricin normalised to the housekeeping gene 18S. After removing outliers, data for normal, aging, and menopausal rabbits for each knee ligament (ACL, PCL, MCL, LCL) were compared using ANOVA with linear contrasts or Kruskal-Wallis test with Conover post-hoc analysis. For ACLs, the mRNA levels for lubricin were increased in menopausal and aging rabbits compared with normal rabbits (p<0.056). For PCLs, trends for increased lubricin mRNA levels were found when comparing menopausal and aging rabbits with normal rabbits (p<0.092). For MCLs, the mRNA levels for lubricin were increased in menopausal and aging rabbits compared with normal rabbits (p<0.050). For LCLs, no differences in lubricin mRNA levels were detected comparing the three groups. For all four knee ligaments (ACL, PCL, MCL, LCL), no differences in lubricin mRNA levels were detected comparing the ligaments from menopausal rabbits with those from aging rabbits. Lubricin plays a role in collagen fascicle lubrication in ligaments (1,2). Increased lubricin gene expression was associated with mechanical changes (including decreased modulus and increased failure strain) in the aging rabbit MCL (3). Detection of similar molecular changes in the ACL, and possibly the PCL, may indicate that their mechanical properties may also change as a result of increased lubricin gene expression, thereby potentially pre-disposing these ligaments to damage accumulation. Compared to aging ligaments, aging tendons exhibited decreased lubricin gene and protein expression, and increased stiffness (4). Although opposite changes than aging ligaments, these findings support the relationship between lubricin and modulus/stiffness. The similarities between ligaments in the aging and menopausal groups may suggest that surgically-induced menopause results in a form of accelerated aging in the rabbit ACL, MCL and possibly PCL

Aims

Abduction bracing is commonly used to treat developmental dysplasia of the hip (DDH) following closed reduction and spica casting, with little evidence to support or refute this practice. The purpose of this study was to determine the efficacy of abduction bracing after closed reduction in improving acetabular index (AI) and reducing secondary surgery for residual hip dysplasia.

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Only a few studies have investigated the long-term health-related quality of life (HRQoL) in patients with an idiopathic scoliosis. The aim of this study was to investigate the overall HRQoL and employment status of patients with an idiopathic scoliosis 40 years after diagnosis, to compare it with that of the normal population, and to identify possible predictors for a better long-term HRQoL.

Aims

Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients.

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The risk factors for abnormal spinopelvic mobility (SPM), defined as an anterior rotation of the spinopelvic tilt (∆SPT) ≥ 20° in a flexed-seated position, have been described. The implication of pelvic incidence (PI) is unclear, and the concept of lumbar lordosis (LL) based on anatomical limits may be erroneous. The distribution of LL, including a unusual shape in patients with a high lordosis, a low pelvic incidence, and an anteverted pelvis seems more relevant.

Aims

Refobacin Bone Cement R and Palacos R + G bone cement were introduced to replace the original cement Refobacin Palacos R in 2005. Both cements were assumed to behave in a biomechanically similar fashion to the original cement. The primary aim of this study was to compare the migration of a polished triple-tapered femoral stem fixed with either Refobacin Bone Cement R or Palacos R + G bone cement. Repeated radiostereometric analysis was used to measure migration of the femoral head centre. The secondary aims were evaluation of cement mantle, stem positioning, and patient-reported outcome measures.

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The preventive effects of bisphosphonates on articular cartilage in non-arthritic joints are unclear. This study aimed to investigate the effects of oral bisphosphonates on the rate of joint space narrowing in the non-arthritic hip.

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Periprosthetic fractures (PPFs) around the knee are challenging injuries. This study aims to describe the characteristics of knee PPFs and the impact of patient demographics, fracture types, and management modalities on in-hospital mortality.

Aims

Extracellular vesicles (EVs) are nanoparticles secreted by all cells, enriched in proteins, lipids, and nucleic acids related to cell-to-cell communication and vital components of cell-based therapies. Mesenchymal stromal cell (MSC)-derived EVs have been studied as an alternative for osteoarthritis (OA) treatment. However, their clinical translation is hindered by industrial and regulatory challenges. In contrast, platelet-derived EVs might reach clinics faster since platelet concentrates, such as platelet lysates (PL), are already used in therapeutics. Hence, we aimed to test the therapeutic potential of PL-derived extracellular vesicles (pEVs) as a new treatment for OA, which is a degenerative joint disease of articular cartilage and does not have any curative or regenerative treatment, by comparing its effects to those of human umbilical cord MSC-derived EVs (cEVs) on an ex vivo OA-induced model using human cartilage explants.

Previous retrieval studies demonstrate increased tibial baseplate roughness leads to higher polyethylene backside wear in total knee arthroplasty (TKA). Micromotion between the polyethylene backside and tibial baseplate is affected by the locking mechanism design and can further increase backside wear. The purpose of this study was to examine modern locking mechanisms, in the setting of both roughened and polished tibial baseplates, on backside tibial polyethylene wear. Five TKA models were selected, all with different tibial baseplate and/or locking mechanism designs. Six retrieval tibial polyethylenes from each TKA model were matched based on time in vivo (TIV), age at TKA revision, BMI, gender, number of times revised, and revision reason. Two observers scored each polyethylene backside according to a visual damage score and individual damage modes. Primary outcomes were mean damage score and individual damage modes. Demographics were compared by one-way ANOVA. Damage scores and modes were analysed by the Kruskal-Wallis test and Dunn's multiple comparisons test. There were no differences among the groups based on TIV (p=0.962), age (p=0.651), BMI (p=0.951), gender, revision number, or reason for revision. There was a significant difference across groups for mean total damage score (p=0.029). The polished tibial design with a partial peripheral capture locking mechanism and anterior constraint demonstrated a significantly lower score compared to one of the roughened tibial designs with a complete peripheral-rim locking mechanism (13.0 vs. 22.1, p=0.018). Otherwise, mean total damage scores were not significant between groups. As far as modes of wear, there were identifiable differences among the groups based on abrasions (p=0.005). The polished design with a tongue-in-groove locking mechanism demonstrated a significantly higher score compared to both groups with roughened tibial baseplates (5.83 vs. 0.83, p=0.024 and 5.83 vs. 0.92, p=0.033). Only the two designs with roughened tibial baseplates demonstrated dimpling (5.67 and 8.67) which was significant when compared against all other groups (p0.99). No other significant differences were identified when examining burnishing, cold flow, scratching, or pitting. No polyethylene components exhibited embedded debris or delamination. Total damage scores were similar between all groups except when comparing one of the polished TKA design to one of the roughened designs. The other TKA model with a roughened tibial baseplate had similar damage scores to the polished designs, likely due to its updated locking mechanism. Dimpling wear patterns were specific for roughened tibial baseplates while abrasive wear patterns were identified in the design with a tongue-in-groove locking mechanism. Our study showed even in the setting of a roughened tibial baseplate, modern locking mechanisms decrease backside wear similar to that of other current generation TKA designs

Aims

There is a lack of high-quality research investigating outcomes of Ponseti-treated idiopathic clubfeet and correlation with relapse. This study assessed clinical and quality of life (QoL) outcomes using a standardized core outcome set (COS), comparing children with and without relapse.

Aims

Clear cell sarcoma (CCS) of soft-tissue is a rare melanocytic subtype of mesenchymal malignancy. The aim of this study was to investigate the clinical and therapeutic factors associated with increased survival, stratified by clinical stage, in order to determine the optimal treatment.

Aims

Bacterial infection activates neutrophils to release neutrophil extracellular traps (NETs) in bacterial biofilms of periprosthetic joint infections (PJIs). The aim of this study was to evaluate the increase in NET activation and release (NETosis) and haemostasis markers in the plasma of patients with PJI, to evaluate whether such plasma induces the activation of neutrophils, to ascertain whether increased NETosis is also mediated by reduced DNaseI activity, to explore novel therapeutic interventions for NETosis in PJI in vitro, and to evaluate the potential diagnostic use of these markers.

Aims

Serum inflammatory parameters are widely used to aid in diagnosing a periprosthetic joint infection (PJI). Due to their limited performances in the literature, novel and more accurate biomarkers are needed. Serum albumin-to-globulin ratio (AGR) and serum CRP-to-albumin ratio (CAR) have previously been proposed as potential new parameters, but results were mixed. The aim of this study was to assess the diagnostic accuracy of AGR and CAR in diagnosing PJI and to compare them to the established and widely used marker CRP.

Aims

The open Latarjet procedure is a widely used treatment for recurrent anterior instability of the shoulder. Although satisfactory outcomes are reported, factors which influence a patient’s experience are poorly quantified. The aim of this study was to evaluate the effect of a range of demographic factors and measures of the severity of instability on patient-reported outcome measures in patients who underwent an open Latarjet procedure at a minimum follow-up of two years.

Introduction. Successful cementless acetabular designs require sufficient initial stability between implant and bone (with interfacial motions <150 μm) and close opposition between the porous coating and the reamed bony surface of the acetabulum to obtaining bone ingrowth and secondary stability. While prior generations of cementless components showed good clinical results for long term fixation, modern designs continue to trend toward increased porosity and improved frictional characteristics to further enhance cup stability. Objectives. We intend to experimentally assess the differences in initial stability between a hemispherical acetabular component with a highly porous trabecular tantalum fixation surface (Continuum. ®. Acetabular System, Zimmer Inc, Warsaw, IN)(Fig 1) and a hemispherical component with the new highly porous Trabecular Titanium. ®. surface (Delta TT, Lima Corporate, Italy)(Fig 2) manufactured by electron beam melting. Material and methods. A total of 16 cups were used, 8 for each type. Each cup was used 4 times. Cups were implanted in polyurethane foam blocks with 1mm interference fit and subsequently edge loaded to failure. Two different foam block densities (0.24 g/cm. 3. and 0.32g/cm. 3. ) were used to model low- and high-density bone stock. Each cup was seated into a block under displacement control using a servohydraulic test machine (MTS Bionix 858, Eden Praire, MN) to engage the locking mechanism until axial forces reach 8 to 10 kN. During insertion, force and displacement were recorded to determine the implantation force for each component. After seating, initial acetabular component fixation was assessed using an edge loading test. Descriptive statistics are presented as means and standard deviations for continuous variables. The Kruskal-Wallis test was used to assess the effect of Cup on the outcomes: (1) Insertion force, (2) Insertion energy, (3) Ultimate load, (4) Yield load, and (5) Ultimate Energy. Pairwise comparisons were done using Mann-Whitney U test for significant outcomes and multiple comparisons were adjusted using Bonferroni correction. All analyses were performed with SAS version 9.3 (SAS Institute, Inc., Cary, NC, USA); a p-value less than 0.05 was considered statistically significant. Results. Delta TT cup required the same seating force (p=0.014) and 18% higher insertion energy (p=0.002) for fully seating compared to Continuum cup, however this difference is not clinically relevant. Delta TT cup exibithed more stability, as exibithed by significantly higher (35%) energy to ultimate load (p=0.014). No statistical differences were found in Ultimate load and Yield load among the 2 cups. Cups in higher density foam required higher force and energy to be seated. In edge load testing higher densities blocks generated higher force and energy accross all cup designs. Conclusions. The result of this study indicate increased interface stability in Trabecular Titanium cup compared to Porous tantalum cup with a low incresing in the energy required for fully seating

Mesenchymal stem cells (MSCs) are self-renewing, multipotent cells that could potentially be used to repair injured cartilage in diseases. The objetive was to analyze different sources of human MSCs to find a suitable alternative source for the isolation of MSCs with high chondrogenic potential. Femoral bone marrow, adipose tissue from articular and subcutaneous locations (hip, knee, hand, ankle and elbow) were obtained from 35 patients who undewent different types of orthopedic surgery (21 women, mean age 69.83 ± 13.93 (range 38–91) years. Neoplasic and immunocompromised patients were refused. The Ethical Committee for Clinical Research of the Government of Aragón (CEICA) approved the study and all patients provided informed consent. Cells were conjugated wiith monoclonal antibodies. Cell fluorescence was evaluated by flow cytometry using a FACSCalibur flow cytometer and analysed using CellQuest software (Becton Dickinson). Chondrogenic differentiation of human MSCs from the various tissues at P1 and P3 was induced in a 30-day micropellet culture [Pittenger et al., 1999]. To evaluate the differentiation of cartilaginous pellet cultures, samples were fixed embedded in paraffin and cut into 5- υm-thick slices. The slices were treated with hematoxylin-eosin and safranin O (Sigma-Aldrich). Each sample was graded according to the Bern Histological Grading Scale [Grogan et al., 2006], which is a visual scale that incorporates three parameters indicative of cartilage quality: uniform and dark staining with safranin O, cell density or extent of matrix produced and cellular morphology (overall score 0–9). Stained sections were evaluated and graded by two different researchers under a BX41 dual viewer microscope or a Nikon TE2000-E inverted microscope with the NIS-Elements software. Statistics were calculated using bivariate analysis. Pearson's χ2 or Fisher's exact tests were used to compare the Bern Scores of various tissues. To evaluate the cell proliferation, surface marker expression and tissue type results, ANOVA or Kruskal-Wallis tests were used, depending on the data distribution. Results were considered to be significant when p was < 0.05. MSCs from all tissues analysed had a fibroblastic morphology, but their rates of proliferation varied. Subcutaneous fat derived MSCs proliferated faster than bone marrow. MSCs from Hoffa fat, hip and knee subcutaneous proliferated slower than MSCs from elbow, ankle and hand subcutaneous. Flow cytometry: most of cells lacked expression of CD31, CD34, CD36, CD117 (c-kit), CD133/1 and HLA-DR. At same time 95% of cells expressed CD13, CD44, CD59, CD73, CD90, CD105, CD151 y CD166. Fenotype showed no differences in cells from different anatomic places. Cells from hip and knee subcutaneous showed a worst differentiation to hyaline cartilage. Hoffa fat cells showed high capacity in transforming to hyaline cartilage. Cells from different anatomic places show different chondrogenic potential that has to be considered to choose the cells source

Children with cerebral palsy (CP) often present femoral bone deformities not accounted for in generic musculoskeletal models [1,2]. MRI-based models can be used to include subject-specific muscle paths [3,4], although this is a time-demanding process. Recently, non-rigid deformation techniques have been used to transform generic bone geometry, including muscle points, onto personalized bones [5]. However, it is still unknown to what extent such an approximation of subject-specific detail affects calculated hip contact forces (HCFs) during gait in CP children. Seven children diagnosed with diplegic CP walked independently at self-selected speed. 3D marker trajectories were captured using Vicon (Oxford Metrics, UK) and force data was measured using two AMTI force platforms (Watertown, MA). MR-images were acquired (Philips Ingenia 1.5T) of all subjects lying supine. Firstly, a generic model [6] was scaled using the marker positions of a static pose. Secondly, a MRI-model containing the subject-specific bone structures and muscle paths of all hip and upper leg muscles was created [3]. Thirdly, the generic femur and pelvis geometries and muscle points were transformed onto the image-based femur and pelvis using an advanced non-rigid deformation procedure (Materialise N.V.). For all models, further analyses were performed in OpenSim 3.1 [7]. A kalman smoother procedure was used to calculate joint angles [8]. Muscle forces were calculated using a static optimization minimizing the sum of squared muscle activities. Next, HCFs were calculated and normalized to body weight (BW). First and second peak HCFs were determined and used for a Kruskal-Wallis test to determine differences between models. In case of a significant difference, a post-hoc rank-based multiple comparison test with Bonferonni adjustment was used. Further, average absolute differences in muscle points between the models was calculated, as well as average differences in moment arm lengths (MALs), reflecting muscle function. Where the scaled generic muscle points differed on average 2.49cm from the MRI points, the non-rigidly deformed points differed 1.54cm from the MRI muscle points. Specifically, the tensor fascia latae differed most between the deformed and MRI models (11.7cm). When considering MALs, the gluteii muscles present an altered function for the generic and deformed models compared to the MRI model for all degrees of freedom of the hip at the time of both HCF peaks. The differences between models resulted in a significantly increased second peak HCF for the MRI models compared to the generic models (first peak average HCF: 3.88BW, 3.95BW and 4.90BW; second peak average HCF: 3.03BW, 4.89BW and 5.32BW for the generic, MRI and non-rigidly deformed models respectively). Although not significantly different, the deformed models calculated slightly increased HCFs compare to the MRI models. The generic models underestimated HCFs compared to the MRI models, while the non-rigidly deformed models slightly overestimated HCFs. However, differences between the deformed and MRI models in terms of muscle points and MALs remain, specifically for the gluteii muscles. Therefore, further user-guided modification of the model based on MR-images will be necessary

Aims

Adenosine, lidocaine, and Mg²⁺ (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery.

Introduction. Failure rates of Metal-on-Metal (MoM) ASR XL hip implants have been unacceptably high compared with other bearing surfaces, so patients must be monitored over the time checking for disorders in clinical condition, blood tests or in diagnostic imaging. Objectives. We have carried out a continuing prospective investigation to evaluate the relationship between blood metal ions measurements and ultrasound levels and to evaluate if ultrasound score can predict a future indication to revision. Materials and methods. From DePuy Recall of 2010 we have monitored 106 patients (51 males, 55 females, mean age 63.6) with ASRXL implants. The controls were performed annually. The following scales were used for patients evaluation:. Ultrasound score: 0 none; 1 fluid collection <20 mm, 2 fluid collection <20 mm, 3 solid mass: metallosis. Blood metal levels of Chromium-Cobalt (Cr-Co) (μg/l = ppb): normal <3 ppb, alert between 3 and 7 ppb, pathologic <7 ppb. Clinical Score: Harris Hip Score. Rx score, evaluating the prosthetic-bone integration and the inclination of acetabular component. Patients who presented positive clinical-instrumental conditions and values of Cr and Co > 3 mg/l were checked every 6 months. Statistical analysis was carried out with Non-parametric Kruskal-Wallis test and two factors Analysis of Variance using SAS System vers. 9.4. Results. The follow-up included 110 implants (4 are bilateral case). 43 patients (39,1 %) underwent revision surgery for failed MoM utilizing ceramic-on-polyethylene devices. At a mean time of 65,7 +/− 15,9 months, 47 patients had a ultrasound score of 0 (13 revised), 32 patients had a ultrasound score of 1 (9 revised), 20 patients had a ultrasound score of 2 (15 revised), 7 patients had a ultrasound score of 3 (6 revised); 44 patients had Cr value < 3 ppb (5 revised), 28 patients had Cr value <3 ppb<7 (6 revised), 34 patients had Cr value <7 ppb (32 revised), 25 patients had Co value < 3 ppb (5 revised), 20 patients had Co value <3 ppb<7 (1 revised), 61 patients had Co value > 3 ppb (37 revised). A positive correlation between blood metal ions values and ultrasound levels (p<0,001) and a statistically significant interaction between ultrasound score and indication to revision (p=0,037) were found. Discussion and Conclusion. As reported in literature also in our experience the ASR XL implant was afflicted by an excessive revision rate, associated with levels of metal ions significantly higher than other hip bearing surfaces. Our results demonstrate a positive correlation between blood Cr and Co levels and the amount of fluid collection: at higher levels of fluid collection correspond higher levels of blood metal ions. Since statistical analysis confirmed that the level of ultrasound score is correlated with indication to revision it is suggested to use ultrasounds, if the score is 2 or more, as parameter to revise MoM implants even in absence of pathologic blood ions levels

Purpose. Previous retrieval studies demonstrate increased tibial baseplate roughness leads to higher polyethylene backside wear in total knee arthroplasty (TKA). Micromotion between the polyethylene backside and baseplate is affected by the locking mechanism design and can further increase backside wear. This study's purpose was to examine modern locking mechanisms influence, in the setting of both polished and non-polished tibial baseplates, on backside tibial polyethylene damage and wear. Methods. Five TKA models were selected with different tibial baseplate and/or locking mechanism designs. Six retrieval tibial polyethylenes from each TKA model were matched based on time in vivo (TIV), age at TKA revision, BMI, gender, number of times revised, and revision reason. Two observers visually assessed each polyethylene. Primary outcomes were visual damage scores, individual visual damage modes, and linear wear rates determined on micro-computed tomography (micro-CT) scan in mm/year. Demographics were compared by one-way ANOVA. Damage scores, damage modes, and linear wear were analyzed by the Kruskal-Wallis test and Dunn's multiple comparisons test. Results. There were no differences among the groups based on TIV (p=0.962), age (p=0.609), BMI (p=0.951), gender, revision number, or reason for revision. There was a significant difference across groups for visual total damage score (p=0.031). The polished tibial design with a partial peripheral capture locking mechanism and anterior constraint demonstrated a significantly lower score compared to one of the non-polished tibial designs with a complete peripheral-rim locking mechanism (13.0 vs. 22.0, p=0.019). Otherwise, mean total damage scores were not significant between groups. There were identifiable differences among the groups based on abrasions (p=0.006). The polished design with a tongue-in-groove locking mechanism demonstrated a significantly higher score compared to one of the designs with a non-polished baseplate (5.83 vs. 0.83, p=0.016). Only the two designs with non-polished baseplates demonstrated dimpling (5.67 and 8.67), which was significant when compared against all other groups (p<0.0001), but not against each other (p>0.99). No other significant differences were identified when examining burnishing, cold flow, scratching, or pitting. No polyethylene components exhibited embedded debris or delamination. There was a significant difference among groups for linear wear on micro-CT scanning (p=0.003). Two of the polished baseplate designs, one with the partial peripheral rim capture and one with the tongue-in-groove locking mechanism, demonstrated significantly lower wear rates than the non-polished design with a complete peripheral-rim locking mechanism (p=0.008 and p=0.032, respectively). There were no other differences in wear rates between groups. Conclusions. Total damage scores and wear rates were similar between all groups except when comparing two of the polished TKA designs to one of the non-polished baseplate designs. The other TKA model with a non-polished tibial baseplate had similar damage scores and wear rates to the polished designs, likely due to its updated locking mechanism. Dimpling was specific for non-polished tibial baseplates while abrasions were identified in the design with a tongue-in-groove locking mechanism. Our study showed even in the setting of a non-polished tibial baseplate, modern locking mechanisms can decrease backside damage and wear similar to that of other current generation TKA designs. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Aims

To investigate the correlations among cytokines and regulatory T cells (T-regs) in ankylosing spondylitis (AS) patients, and their changes after anti-tumour necrosis factor-α (TNF-α) treatment.

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Periprosthetic fracture and implant loosening are two of the major reasons for revision surgery of cementless implants. Optimal implant fixation with minimal bone damage is challenging in this procedure. This pilot study investigates whether vibratory implant insertion is gentler compared to consecutive single blows for acetabular component implantation in a surrogate polyurethane (PU) model.

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We aimed to assess the cumulative risk of total hip arthroplasty (THA) from in situ fixation for slipped capital femoral epiphysis (SCFE) after a follow-up of almost 50 years.

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The aim of this study is to evaluate the surgical treatment with the best healing rate for patients with proximal femoral unicameral bone cysts (UBCs) after initial surgery, and to determine which procedure has the lowest adverse event burden during follow-up.

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The aim of this study was to investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies. We asked: is there a difference in APP-PT between young symptomatic patients being evaluated for joint preservation surgery and an asymptomatic control group? Does APP-PT vary among distinct acetabular and femoral pathomorphologies? And does APP-PT differ in symptomatic hips based on demographic factors?

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The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition.

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Postoperative length of stay (LOS) and discharge dispositions following arthroplasty can be used as surrogate measurements for improvements in patients’ pathways and costs. With the increasing use of robotic technology in arthroplasty, it is important to assess its impact on LOS. The aim of this study was to identify factors associated with decreased LOS following robotic arm-assisted total hip arthroplasty (RO THA) compared with the conventional technique (CO THA).

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The aim of this study was to determine the rate of indocyanine green (ICG) staining of bone and soft-tissue tumours, as well as the stability and accuracy of ICG fluorescence imaging in detecting tumour residuals during surgery for bone and soft-tissue tumours.

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Acetabular fractures are associated with long-term morbidity. Our prospective cohort study sought to understand the recovery trajectory of this injury over five years.

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Current diagnostic tools are not always able to effectively identify periprosthetic joint infections (PJIs). Recent studies suggest that circulating microRNAs (miRNAs) undergo changes under pathological conditions such as infection. The aim of this study was to analyze miRNA expression in hip arthroplasty PJI patients.

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Periprosthetic hip fractures (PPFs) after total hip arthroplasty are difficult to treat. Therefore, it is important to identify modifiable risk factors such as stem selection to reduce the occurrence of PPFs. This study aimed to clarify differences in fracture torque, surface strain, and fracture type analysis between three different types of cemented stems.

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The aim of this prospective study was to assess the long-term clinical, radiological, functional, and quality of life (QoL)-related outcome of patients treated with the synthetic Ligament Advanced Reinforcement System (LARS) device for anterior cruciate ligament (ACL) rupture.

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The management of periprosthetic joint infection (PJI) remains a major challenge in orthopaedic surgery. In this study, we aimed to characterize the local bone microstructure and metabolism in a clinical cohort of patients with chronic PJI.

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This study aimed to investigate the role and mechanism of meniscal cell lysate (MCL) in fibroblast-like synoviocytes (FLSs) and osteoarthritis (OA).

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In-hospital length of stay (LOS) and discharge dispositions following arthroplasty could act as surrogate measures for improvement in patient pathways, and have major cost saving implications for healthcare providers. With the ever-growing adoption of robotic technology in arthroplasty, it is imperative to evaluate its impact on LOS. The objectives of this study were to compare LOS and discharge dispositions following robotic arm-assisted total knee arthroplasty (RO TKA) and unicompartmental arthroplasty (RO UKA) versus conventional technique (CO TKA and UKA).

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Femoroacetabular impingement (FAI) patients report exacerbation of hip pain in deep flexion. However, the exact impingement location in deep flexion is unknown. The aim was to investigate impingement-free maximal flexion, impingement location, and if cam deformity causes hip impingement in flexion in FAI patients.

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Staphylococcus aureus is a major cause of septic arthritis, and in vitro studies suggest α haemolysin (Hla) is responsible for chondrocyte death. We used an in vivo murine joint model to compare inoculation with wild type S. aureus 8325-4 with a Hla-deficient strain DU1090 on chondrocyte viability, tissue histology, and joint biomechanics. The aim was to compare the actions of S. aureus Hla alone with those of the animal’s immune response to infection.

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The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs).

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This study aimed to describe practice variation in the use of total hip arthroplasty (THA) for older patients with femoral neck fracture and to determine the association between patient, surgeon, and institution factors and treatment with THA.

The purpose of this study was to evaluate whether epidural fibrosis formation around the spinal cord was affected by endogenous oestrogen deficient state after lumbar laminectomy in the rats. Thirty-six 12-month-old adult female Sprague-Dawley rats were used in this study. Bilaterally ooferectomy were done in 18 rats. Rats were divided into two groups: oophrectomised (oestrogen deficient) group and sham operated (oestrogen maintained) group. Three weeks after the ooferectomy each rat underwent complete bilaterally laminectomy at the L2 and L3 vertebral levels (two levels per rat). The rats were randomly divided into three equal groups (12 rats in each group). The rats were sacrificed at four, eight, and twelve weeks postoperatively and the lumbar spine excised en bloc, fixed and decalcified. Section stained with hematoxylin and eosin and Masson’s trichrome were used to evaluate epidural fibrosis, acute inflammatory cells, chronic inflammatory cells and vascular proliferation. Sections were analyzed by investigator blinded to the study and graded on a five-point grading system. Statistic were performed using Mann-Whitney U test when compare two variable and Kruskal-Wallis test when compare more than two variables. Compared with the oopherectomised group, the sham operated group showed decreased rate of epidural fibrosis and higher acute and chronic inflammatory cells response at four and eight weeks but this was no statistically significant (p> 0.05). The results of this study revealed that endogenous oestrogen may decrease epidural fibrosis formation after lumbar laminectomy in the rats

The purpose of this study was to evaluate the results of subcutaneous ulnar nerve transposition in the treatment of Cubital Tunnel Syndrome (CTS) and the influence of prognostic factores such as preoperative McGowan stage, age and duration of symptoms. 36 patients (17 men and 19 women) with CTS who underwent subcutaneous ulnar nerve transposition between 2006 and 2009 were evaluated postoperatively, an average follow-up of 28 months. Sensory and motor recovery was evaluated clinically. The postoperative outcome was based on modified Bishop score, subjective assessment of function and on the degree of patient satisfaction. The dominant side was involved in 61% cases and the mean age was 51.2 years. There were 9 (25%) McGowan stage I, 18 (50%) stage II and 9 stage III patients. We used the Mann-Whitney and Kruskal-Wallis test to compare continuous variables and chi-square and Fisher Exact Test for categorical variables. There was a statistically significant improvement of sensory (p=0.02) and motor (p=0.02) deficits. We obtained 21 (58.3%) excellent results, seven (19.4%) fair, six (16.7%) satisfactory, and two bad ones (5.55%). There was a statistically significant improvement of function (p<0.001). There is controversy in the literature regarding the best surgical treatment for CTS. The duration and severity of symptoms and advanced age, more than the surgical technique, seem to influence prognosis. With the technique used, the satisfaction rate was 86% and 72% recovered their daily activities without limitations. 78% of patients with severe neuropathy improved after surgery. The rates of postoperative complications were comparable with those of other studies. The severity of neuropathy and duration of symptoms (>12months) pre-operatively, but not age, had a negative influence on the outcome. The results showed that the subcutaneous ulnar nerve transposition is safe and effective for postoperative clinical sensory and motor recovery for several degrees of severity in CTS. Given the major prognostic factors, surgical treatment should be advocated as soon as axonal loss has become clinically evident

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Head-taper corrosion is a cause of failure in total hip arthroplasty (THA). Recent reports have described an increasing number of V40 taper failures with adverse local tissue reaction (ALTR). However, the real incidence of V40 taper damage and its cause remain unknown. The aim of this study was to evaluate the long-term incidence of ALTR in a consecutive series of THAs using a V40 taper and identify potentially related factors.

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Cam and pincer morphologies are potential precursors to hip osteoarthritis and important contributors to non-arthritic hip pain. However, only some hips with these pathomorphologies develop symptoms and joint degeneration, and it is not clear why. Anterior impingement between the femoral head-neck contour and acetabular rim in positions of hip flexion combined with rotation is a proposed pathomechanism in these hips, but this has not been studied in active postures. Our aim was to assess the anterior impingement pathomechanism in both active and passive postures with high hip flexion that are thought to provoke impingement.

Introduction. Proper alignment (tibial alignment, femoral alignment, and overall anatomic alignment) of the prosthesis during total knee replacement is critical in maximizing implant survival[7] and to reduce polyethylene wear[1]. Poor overall anatomic alignment of a total knee replacement was associated with a 6.9 times greater risk of failure due to tibial collapse, that varus tibial alignment is associated with a 3.2 times greater risk[2] and valgus femoral alignment is associated with a 5.1 times greater risk of failure[7]. To reduce this variability intramedullary (IM) instruments have been widely used, with increased risk of the fat emboli rate to the lungs and brain during TKA[6] and possible increase of blood loss[4, 5]. Or, alternatively, navigation has been used to achieve proper alignment and to reduce morbidity[3]. Recently, for distal femoral resection, inertial sensors have been coupled to extramedullary (EM) instruments to improve TKA surgery in terms of femoral implant alignment, with respect to femoral mechanical axis, and reduced morbidity by avoidance of IM canal violation. The purpose if this study is to compare blood loss and alignment of distal femoral cut in three cohorts of patients: 1 Operated with inertial based cutting guide; 2 Operated with navigation instruments; 3 operated with conventional IM instruments. Material and methods. From September to November 2014 30 consecutive patients, eligible for TKA, were randomly divided into three cohorts with 10 patients each:x 1 “EM Perseus”, patient operated with EM inertial based instruments (Perseus, Orthokey Italia srl, Florence, Italy); 2 “EM Nav”, operated with standard navigated technique, where bone resections were planned and verified by mean of navigation system (BLUIGS, Orthokey Italia srl, Florence, Italy); 3 “IM Conv”, operated with standard IM instrumentation. All patients were operated by the same surgical technique, implanted TKA were mobile bearing PS models, Gemini (Waldemar Link, Hamburg, Germany) and Attune (Depuy, Warsaw, Indiana). Anteroposterior, lateral, and full-limb weightbearing views preoperatively and postoperatively at discharge were obtained, taking care of neutral limb rotational positioning in all patients enrolled in the study. Angles between femoral mechanical axis and implant orientation on frontal and lateral planes were measured with a CAD software (Rhinoceros 3, McNeel Europe, Rome, Italy) by two independent persons, average value was used for statistical analysis. Haemoglobin values were recorded at three time intervals: the day before surgery, at 24h follow-up and at patients discharge. Statistical analysis. Kruskal-Wallis test was used to compare differences between the three cohorts in blood loss and femoral implant alignment. Results. All the three cohorts were comparable in terms of age, sex, preoperative limb alignment and preoperative haemoglobin values (Tab. 1). Haemoglobin ad discharge was reduced for all three cohorts (Tab. 2), no significant differences was found even if IM Conv group showed higher loss compared to EM Perseus and EM Nav groups. Femoral implant alignment deviation, considering perpendicularity with femoral mechanical axis as goal, was comparable in frontal and lateral plane for all three cohorts (Tab. 2). Discussion. The aim of the study was to compare the accuracy in femoral component positioning, on the coronal and sagittal plane obtained with a new inertial based EM instrument, with a standard IM distal femoral cutting jig and with navigation. We confirm our hypothesis that the use of inertial based EM instruments to perform the distal femoral bone cut in TKA is reliable and at least as accurate as the standard IM technique and navigation. Our study did not show a statistical decrease in blood loss when the femoral canal was not reamed (in inertial based EM, and navigated groups), even if patient operated with IM instruments had sensibly higher blood loss compared to the other two groups. This study was not exactly powered for that purpose, a study with a larger cohort and strict patient selection criteria would be required. This study demonstrates that inertial based EM instruments is accurate for femoral component alignment in TKA and compares favorably to navigation systems and standard IM techniques. Other indications for the use of inertial based EM instruments include all major femoral extraarticular deformities, the presence of ipsilateral long-stemmed hip arthroplasty, and the presence of hardware such as distal femoral plates and screws or IM nails

Introduction. There has been much discussion in the literature concerning the possible detrimental effects of metal ion circulating in the body after MOM THR. This study seeks to evaluate the differences in observed Co and Cr levels in blood after TKR and several popular THR options. Method. We compared chromium (Cr) and cobalt (Co) levels between three different hip replacement bearings and total knee replacements (TKR) over time. Blood samples were taken from patients who received metasul 28 mm (n=25), metasul 32 mm (n=25) and Durom (n=50) hip bearings and TKR (n=100), pre- operatively and post operatively at six, twelve and twenty-four month intervals. Blood samples were analysed for Co and Cr levels using ICPMS (Inductively coupled mass spectrometry) and reported as parts per billion. Results were compared using Kruskal-Wallis Test (nonparametric ANOVA). Results. No increase was seen in serum Co and Cr levels in TKR patients over time. There were statistically significant differences in Co levels between the TKR group and all bearing surfaces of THR (28, 32 mm and Durom), p<0.001 at two years. Cr levels were significantly higher (p<0.001) in Durom bearings vs TKR only at one year decreasing to p<0.01 at two years. Comparing ion levels over time in the hip group, only in the Durom cohort did serum Cr levels preop vs 12 and 24 months reach a statistical significance of p<0.001. For Co, all three bearings showed a statistically significant increment over time (p<0.01). Highest levels of ions were seen with the 28 mm bearings but comparison between the three THR bearings at two years showed no statistical difference in Cr or Co levels. Median blood Cr concentration did not exceed 1.6 ppb in any subgroup. All median Co concentrations were below 0.8ppb. Conclusions. Over a two-year period Co and Cr levels for TKR did not differ appreciably from preoperative levels. Both Cr and Co levels were only mildly elevated post THR for all bearings. Metasul 28 mm bearings require further follow-up as the Co levels were not seen to plateau at two years

Purpose. To evaluate the five year Radiostereometric Analysis (RSA) results of the NexGen LPS Trabecular Metal Tibial Monoblock component (TM) and the NexGen Option Stemmed cemented component (Cemented), (Zimmer, Warsaw IN). Method. 70 patients with osteoarthritis were included in a randomized series to receive either the TM implant or the cemented NG component. Surgery was performed by high volume arthoplasty specialists using standardized procedure. RSA exams were obtained postoperatively, at six months, one year, two years and five years. RSA outcomes were translations, rotations and maximum total point motion (MTPM) of the components. MTPM values were used to classify implants as ‘at risk’ or ‘stable’. Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores were gathered at all follow-ups. An analysis of variance was used to test for differences in age, body mass index (BMI), and subjective measures between implant groups. The Kruskal-Wallis test was used to investigate differences in maximum total point motion between implant groups. An analysis of variance was used to test for differences in translations and rotations between groups. Fishers exact test was used to investigate differences in proportions of implants found to be at risk between groups. Results. At the five year follow-up, 43 patients were able to be reached and were willing to participate in the follow-up exam. There were 25 in the trabecular metal group and 18 in the cemented group. There were no differences in subjective measures (WOMAC) between implant groups at any follow-up. At the five year follow-up there was no difference in MTPM between the cemented and trabecular metal groups (p=0.94) Compared to the cemented components, the trabecular metal tibial components had significantly higher subsidence than the cemented components (p=0.001). There were no other significant differences. The proportion of at risk components at five years was 2 of 16 (0.11, 95% CI, 0.03–0.33) in the cemented group and was 0 of 25 (0.0, 95% CI, 0.0–0.13) in the trabecular metal group (p=0.17). Conclusion. In the two year report on this cohort of patients, we indicated our uncertainty concerning the long term stability of the Trabecular Metal tibial implant due to the high initial migration seen in some cases. In this report we have seen stability of this implant out to five years and migrations in this period below the level of detection of our system in all cases. Given these results it is with increased confidence that we can state that this implant appears to achieve solid fixation despite high initial levels of migration

Heterotopic Ossification (HO) is a common finding in the radiographs of patients who have had total hip replacement surgery (42–57%). HO is responsible for pain and limitation of postoperative motion in 3–10% of these patients. This study was initiated to find out if pulsed lavage affected the incidence of HO. A prospective randomised double-blind trial was initiated consisting of 115 primary total hip arthroplasties. Intra-operative irrigation was provided by a 50 ml syringe and limited to 500 ml of room-temperature normal saline or pulsed lavage with three litres of room-temperature normal saline. The grade of HO at one year was classified according to Brooker et al. Statistical analysis of the results was made using the chi-squared test and the Kruskal-Wallis test. The incidence of HO in this group of primary total hip arthroplasties was 57. 4%. The majority of cases with HO were graded 1 or 2 (42. 6%). No statistical significance was found to exist between the two methods of irrigation in relation to HO (chi-squared p value = 0. 456). From an analysis of the known risk factors for HO, only the type of osteoarthritis was shown to statistically influence the incidence of HO. The process of HO is thought to be as a result of the differentiation of mesenchymal cells into osteoprogenitor cells. Theories have proposed that the inducing agent and/or the mesenchymal cells arise from bone at the time of the operation, although systemic agents have also been proposed. If the inducing agent or precursor cells were released from the bone intraoperatively, thorough irrigation could be expected to have an association with a lower incidence of HO. The lack of correlation between irrigation and incidence of HO indicates this is unlikely to be the mechanism

Background: The purpose of the study was to evaluate whether anteroposterior translation (APT) after ACL reconstruction with intraoperative balancing of the transplant tension to that of the contralateral ACL could be obtained at follow up. Additionally, differences of APT’s following ACL reconstruction using either autologous patella bonetendon–bone (BTB) or autologous quadriceps-tendon-bone (QTB) were assessed. Methods: In a consecutive series of 44 patients (44 knees), ACL deficiency was treated in 30 patients (median age: 33, 16–58, 20 male, 22 right knee) with BTB–and in 14 patients (median age: 31, 17–50, 8 male, 10 right knee) with QTB-reconstruction. APT was evaluated in 20° knee flexion in the affected and healthy contralateral knee using the Rolimeter. ®. Measurements were performed in both knees preoperative, during, and immediately after ACL-reconstrucion, as well as 3, 6 and 12 months postoperatively in triplates. For statistical analysis the non-parametrical Kruskal-Wallis Test (post test: Dunn’s Test) was used. Results: Statistically significant decreases of APT were observed between pre–and intraoperative measurements in the BTB–and the QTB-group due to ACL reconstruction (11.1±2.0 to 6.3±0.7mm; p< 0.001 in the BTB and 11.1±2.3 to 6.8±1.2mm; p< 0.001 in QTB group). At the intraoperative measurements, there were no differences in APT between the contralateral healthy knee and the reconstructed knee in both groups. During the follow up, significant loss of APT in the balanced reconstructed knees were only observed in the BTB group after 12 months (6.3±0.7 to 7.5±1.2mm; p< 0.05). Conclusion: After reconstruction of the ACL, BTB–and QTB-ACL reconstruction groups, yielded the same anteroposterior translation (APT) as contralateral healthy knees. This new intraoperative technique provides ACL reconstruction with balancing of the anteroposterior knee translation of the healthy contralateral knee. An increase in APT could be observed 12 months after ACL reconstruction only in the BTB group. Further research is necessary to assess whether QTB-ACL-reconstruction should be preferred regarding preservation of the initial ligament tension at follow up

Introduction. This retrieval analysis study consisted of two goals. The first goal was to determine if there was a difference in the corrosion and fretting damage along the taper interface between large femoral heads in comparison to monopolar hemiarthroplasty heads. The second goal was to examine if the diameter of monopolar hemiarthroplasty heads can influence corrosion and fretting damage along the taper interface. Patients and Methods. This retrieval analysis compared the corrosion and fretting behaviour of 40 mm femoral heads (n = 13) to monopolar hemiarthroplasty heads (n = 17 for a diameter < 50 mm; n = 6 for a diameter ≥ 50 mm) such that all implants had a minimum implantation period of three months, a 12/14 mm taper, and the heads and stems consisted of CoCr alloy. The 40 mm heads articulated with a polyethylene cup whereas the monopolar hemiarthroplasty heads articulated with cartilage. The 40 mm heads were manufactured from one company whereas the monopolar hemiarthroplasty heads were manufactured from four different companies. Corrosion and fretting damage were assessed using a previous technique [1]. Table 1 lists the patient information and reasons for revision whereas Table 2 provides the implant information. The Mann Whitney U test and the Kruskal-Wallis test were performed for identifying significant differences for corrosion and fretting scores that were not normally distributed (α = 0.05). An unpaired student's t-test was conducted for comparing the head corrosion scores for the two head size groups of monopolar hemiarthroplasty implants since these scores were normally distributed. Results. As shown in Table 3, the 40 mm heads had an average head corrosion score of 6.4 ± 9.9 whereas the monopolar hemiarthroplasty heads had an average score of 13.8 ± 13.4 resulting in a significant statistical difference (p = 0.049). In regards to head fretting, the scores were 1.3 ± 1.9 for the 40 mm heads and 10.5 ± 18.2 for the monopolar hemiarthroplasty implants, but the difference was not statistically significant (p = 0.058). There were no significant statistical differences in the corrosion and fretting scores between the four manufacturers. A significant statistical difference was found for the head corrosion scores of the two monopolar hemiarthroplasty head size groups. Monopolar hemiarthroplasty heads with a diameter < 50 mm had an average score of 11.0 ± 10.2 whereas the heads with a diameter ≥ 50 mm yielded scores of 21.8 ± 18.6 (p = 0.043). Discussion/Conclusion. Monopolar hemiarthroplasty heads exhibit more corrosion damage along the taper interface than 40 mm heads. This study also revealed that monopolar hemiarthroplasty implants exhibit more corrosion damage with a larger diameter. This supports the argument that a greater head diameter increases the torque acting along the head-stem taper interface. This would increase the micromotion, which can deteriorate the protective oxide layer, and make the taper interface more vulnerable to crevice corrosion

Aims

We aimed to compare the implant survival, complications, readmissions, and mortality of Vancouver B2 periprosthetic femoral fractures (PFFs) treated with internal fixation with that of B1 PFFs treated with internal fixation and B2 fractures treated with revision arthroplasty.

Introduction: Functional results of hemiarthroplasties in proximal humeral fractures are unpredictable. The correct consolidation of the tuberosities back to the prosthesis seem to be of capital importance in the functional outcome. The objective of the study is to analyze the changes of the tension registered in the sutures passed through the tuberosities when changing the height and version of the prosthesis in a static model and in a dynamic model. Material and Method: Prosthesis positioning: in both static and dynamic model, the prosthesis was placed in anatomical position, anatomical increasing 20° retroversion, increasing height in 1cm and anatomical version, decreasing height in 1 cm and anatomical version, increasing height in 1cm and increasing 20° retroversion, decreasing height in 1 cm and increasing 20° retroversion,. Static study: a 4-part fracture was reproduced in four fresh-frozen shoulder specimens. Sutures were placed between lesser tuberosity and diafisis (sensor 1) between both tuberosities (sensor 2) and between greater tuberosity and diafisis (sensor 3). Traction was performed through supraspinatus, infraspinatus and subescapularis attachments until the breakage of the suture or 1 cm gap between bony fragments. Tensions registered in a computer model. Dynamic study: a 4-part fracture was reproduced in a humeral saw bone. Sutures placed in the same position that in the static model. Saw bone fixed at a robotic arm reproducing cycles of 90° anterior elevation, 30° lateral rotation, 30° internal rotation and retropulsion to starting point. Registering of the tensions. Quantitative values studied through t-student and non parametric values studied through U-Mann-Whitney and Kruskal-Wallis test. Results: In the Static study, the suture placed between the tuberosities is the one that significantly receives more tension. The breakage of the suture happens more frequently when the prosthesis is placed in a lower position and in a lower more retroverted position. In the dynamic study, the suture placed between the greater tuberosity and the diafisis is the one significantly receives more tension. The breakage of the suture happens more frequently when the prosthesis is placed in a lower position and in a lower more retroverted position. Conclusions: When planning sutures between tuberosities in proximal humeral fractures treated with hemiarthroplasty postoperative rehabilitation program has to be considered because different sutures are at risk depending on static or dynamic model. The worst positions of the hemiarthroplasty as far as over tensioning sutures is concerned are the low position and the low more retroverted position

Aims

Low-energy distal radius fractures (DRFs) are the most common upper arm fractures correlated with bone fragility. Vitamin D deficiency is an important risk factor associated with DRFs. However, the relationship between DRF severity and vitamin D deficiency is not elucidated. Therefore, this study aimed to identify the correlation between DRF severity and serum 25-hydroxyvitamin-D level, which is an indicator of vitamin D deficiency.

Press-fit cups have given excellent clinico-radiographical results. This is a retrospective clinico-radiographical study about the long term performance of pure Titanium cementless modular press-fit cups (FitekTM) having, on the outer surface, an oriented multilayer titanium mesh (SulmeshTM) with 65% porosity (average pore size=400–640 micron). The cup was implanted after underreaming the acetabulum by 2 mm. In the cup’s equatorial area there are two “fins” originary designed to improve rotational stability but actually representing two excellent primary mechanical stabilizers. We have evaluated the first 100 consecutive cups implanted in 92 patients with an average FU of 9,7 years (range 9–11 years). All operations have ben performed by the two Senior Authors (PGM and RB). Regarding etiology, we had 43 Primary Arthritis, 37 Dysplastic Arthritis, 12 Osteonecrosis and 8 Post-traumatic Arthritis. results were evaluated with the Harris score. Radiographic evaluation was performed using AP and lateral x-rays pre-op. post-op and at the last follow-up. We had 86 Excellent, 10 Good, 2 Fair and 2 Poor. The 2 Poor results were 2 aseptic loosenings of the stem. The Mann-Whitney nonparametric U test and the Kruskal-Wallis test showed that the survival rate of the 100 analyzed cups, after a mean follow-up of 9.7 years, was 100% (end point: revision for any cause). Etiology was not statistically correlated with post-op score. Nevertheless, dysplastic patients showed inferior results compared to arthritic patients in different parameters, as pain, limp, Range Of Motion (p < 0.05), putting socks and shoes (p < 0.05). Our cups were intentionally implanted and radiographically appear in a fairly horizontal position (36.5° on average). In 6 cases we could calculate an eccentricity of the metal heads proving bidimensional linear wear of the liner (average 0.265 mm / year). At the last follow-up we had 3 femoral osteolysis, while in the acetabular side radiolucent lines were present in 14 % of the cases, never progressive. In no case we found a change of position of the cup. FitekTM cementless cups gave excellent results at 10 years with complete stability and osteo-integration. Excellent primary mechanical stability was given by the rough surface (SulmeshTM) and by the two “fins” in the equatorial area

Crosslinked polyethylene (XPE) was developed to reduce wear in hip and knee arthroplasty. Periprosthetic osteolysis depends on many factors including biological activity of wear particles. This study examines the relative inflammatory effect of different crosslinked polyethylenes compared to ultra-high-molecular-weight-polyethylene (UHMWPE) particles in vivo. Materials and Methods: Wear particles of 3 XPE- (1 sequential irradiated/annealed; 2 remelted inserts) and 1 UHMWPE-insert were isolated from a knee joint simulator (20nm-nucleopore-filter;acid digestion method;ISO). Particles were analysed by scanning electron microscopy (n=66000). For all groups the particles were smooth, granular, irregular and less fibrillar. More than 85% of the particles were submicron. After removal of endotoxin the particles were suspended in a phosphate buffered saline solution (0.1% vol/vol (particle volume/PBS volume)). Endotoxin levels were controlled using standardised endotoxin detection tests (Lonza) in all samples. 40 female Balb/c mice were randomly assigned to one of five treatment groups (according to the national guidelines of animal protection laws): control (n=8); XPE1 (95 kGy E-beam, remelted; n=8); XPE2 (65 kGy E-beam, remelted; n=8), XPE3 (3x30 kGy Gamma, annealed and sequential irradiated; n=8) and UHMWPE particles (n=8). 50 μl of the particle suspension were injected into the murine left knee under sterile conditions. The leukocyte–endothelial cell interactions and the synovial microcirculation were performed by intra-vital fluorescence microscopy one week after particle injection to assess the inflammatory reaction to the particles (by measuring the rolling fraction of leukocytes, the adherent cells and the functional capillary density (FCD)). Data analysis was performed using a computer-assisted microcirculation analysis system (Cap-Image). For the statistical analysis the Kruskal-Wallis test was used to determine differences within the groups, followed by an all pairwise multiple comparison procedure with a Bonferoni correction. The level of significance was set at p< 0.05. Results: The fraction of the rolling leukocytes, adherent cells and FCD increased significantly (p< 0.05) in all bio-materials compared to control group. However, there was no significant difference between the UHMWPE and the XPE particle groups (p> 0.05). Conclusion: Our data suggest that crosslinked polyethylene wear particles do not lead to a higher inflammatory reaction in vivo compared to UHMWPE particles

Introduction: Minimal invasive surgery (MIS) seems to be part of future orthopaedic solutions. Currently, most approaches for the Bernese periacetabular osteotomy (PAO) are characterized by relatively extensive incisions, dissection and detachment of muscles. We have developed a new MIS approach for the Bernese PAO. The purposes were to reduce patient morbidity and to improve the cosmetic result following surgery without negatively influencing the achieved reorientation of the acetabular articular surface. In this study we present the surgical technique, results and compare them to the ilioinguinal (II) approach. Methods: The new MIS technique is a trans-sartorial approach using a three inch skin incision. Previously the II approach was used. From 1999–2006 a total of 215 patients with acetabular dysplasia were operated by the same surgeon in two successive time periods with the II (97) and the trans-sartorial (118) approaches. No supplemental surgery was performed. The two approaches are retrospectively compared regarding perioperative measures, transfusion requirements, complications and the achieved reorientation of the acetabular articular surface. Data are compared by Kruskal-Wallis Test and are presented as median and interquartile range. Results: The trans-sartorial approach significantly reduced days of admission (8 days (7–9) vs. 10 days (8–13), p< 0.0001), duration of surgery (70 min (60–75) vs. 100 min (82.5–120), p< 0.0001), perioperative blood loss (200ml (150–350) vs. 450ml (325–700), p< 0.0001) and the percentage of patients receiving blood transfusion (18.6 % vs. 3.4%). Of severe neurovascular, infectious and technical complications none occurred in the trans-sartorial group and 3 cases of arterial thrombosis were seen in the II group. The achieved reorientation measured by the CE-angle postoperatively had median values of 31° (25–36) in the II group and 33° (29–36) in the trans-sartorial group, p=0.016. The postoperative AI-angles were 10° (2–14) and 3° (0–7) in the II and trans-sartorial groups respectively, p< 0.0001. Discussion: Our shift to the trans-sartorial approach was rewarding as the duration of surgery, perioperative blood loss and transfusion requirements were reduced. The new MIS technique is safe and improves the cosmetic result without negative influence on the achieved reorientation of the acetabular articular surface

Aims

The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance.

Aims

Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost.

There are several techniques in minimally invasive total hip arthroplasty. One of the possible advantages of these techniques is early functional recovery. The purpose of the study was to evaluate possible differences in functional recovery patterns after three different techniques of minimally invasive total hip arthroplasty. Patients and methods: Two hundreds and eighty-eight hips were recruited for this study. All operations were done without cement in all institutes. Acetabular components were Trilogy and femoral components were VerSys (Zimmer, Indiana, USA) in all hips. Mini-incision antero-lateral approach was used for 112 hips (Mini-AL group), mini-incision postero-lateral approach for 53 (Mini-PL group), and muscle sparing antero-lateral approach was used for 123 hips (MS-AL group). There were no significant differences among the three groups for age. All patients were encouraged to walk with full weight-bearing as soon as possible. Early functional outcome was assessed by the attainment of functional milestones, including the number of days post-op to walk 100m with a T-cane and to put on socks. We also analyzed pain during resting and walking, and evaluated muscle strength for abduction before surgery, at one, three, five, seven and 14 days after surgery. Pain was assessed using a visual analog scale. Muscle strength was assessed using a hand held dynamometer (MicroFET-2) in supine position. The post-pre-operative strength ratio was calculated and defined as the recovery ratio. For continuous variables, a Kruskal-Wallis test was used. For comparison among all three groups, the level of significance was set at p< 0.05. For the three multiple comparisons, the level of significance was calculated using the Bonferonni adjustment and was set at p< 0.0165. Results: Mean of the post-op days to walk 100 meters with a T-cane was 4.09 days for MS-AL group, 4.82 for Mini-AL group, and 5.57 for Mini-PL group. MS-AL group showed a significantly earlier recovery than Mini-AL group. Mean of the post-op days to put on socks was 5.86 days for MS-AL group, 7.37 for Mini-AL group, and 9.9 for Mini-PL group. MS-AL group showed a significantly earlier recovery than Mini-AL and Mini-PL groups. There were no differences for resting pain or walking pain at any days among the three groups. There were no differences for recovery ratio of muscle strength for abduction at 3 postoperative days. At 5 days, Mini-AL showed a lower ratio than MS-AL. And at 7 and 14 days, Mini-AL showed a lower ratio than both the MS-AL and Mini-PL group. Conclusion: Muscle sparing antero-lateral technique showed earlier recovery for walking and putting on socks than those using mini-incision techniques

There are several techniques in minimally invasive total hip arthroplasty. One of the possible advantages of these techniques is early functional recovery. The purpose of the study was to evaluate possible differences in functional recovery patterns after three different techniques of minimally invasive total hip arthroplasty. Patients and methods: Two hundreds and eighty-eight hips were recruited for this study. All operations were done without cement in all institutes. Acetabular components were Trilogy and femoral components were VerSys (Zimmer, Indiana, USA) in all hips. Mini-incision antero-lateral approach was used for 112 hips (Mini-AL group), mini-incision postero-lateral approach for 53 (Mini-PL group), and muscle sparing antero-lateral approach was used for 123 hips (MS-AL group). There were no significant differences among the three groups for age. All patients were encouraged to walk with full weight-bearing as soon as possible. Early functional outcome was assessed by the attainment of functional milestones, including the number of days post-op to walk 100m with a T-cane and to put on socks. We also analyzed pain during resting and walking, and evaluated muscle strength for abduction before surgery, at one, three, five, seven and 14 days after surgery. Pain was assessed using a visual analog scale. Muscle strength was assessed using a hand held dynamometer (MicroFET-2) in supine position. The post-pre-operative strength ratio was calculated and defined as the recovery ratio. For continuous variables, a Kruskal-Wallis test was used. For comparison among all three groups, the level of significance was set at p< 0.05. For the three multiple comparisons, the level of significance was calculated using the Bonferonni adjustment and was set at p< 0.0165. Results: Mean of the post-op days to walk 100 meters with a T-cane was 4.09 days for MS-AL group, 4.82 for Mini-AL group, and 5.57 for Mini-PL group. MS-AL group showed a significantly earlier recovery than Mini-AL group. Mean of the post-op days to put on socks was 5.86 days for MS-AL group, 7.37 for Mini-AL group, and 9.9 for Mini-PL group. MS-AL group showed a significantly earlier recovery than Mini-AL and Mini-PL groups. There were no differences for resting pain or walking pain at any days among the three groups. There were no differences for recovery ratio of muscle strength for abduction at 3 postoperative days. At 5 days, Mini-AL showed a lower ratio than MS-AL. And at 7 and 14 days, Mini-AL showed a lower ratio than both the MS-AL and Mini-PL group. Conclusion: Muscle sparing antero-lateral technique showed earlier recovery for walking and putting on socks than those using mini-incision techniques

Aims

Long-term outcomes following the use of human dermal allografts in the treatment of symptomatic irreparable rotator cuff tears are not known. The aim of this study was to evaluate these outcomes, and to investigate whether this would be a good form of treatment in young patients in whom a reverse shoulder arthroplasty should ideally be avoided.

Aims

Acute distal biceps tendon repair reduces fatigue-related pain and minimizes loss of supination of the forearm and strength of flexion of the elbow. We report the short- and long-term outcome following repair using fixation with a cortical button techqniue.

Aims

To determine the role of early MRI in the management of suspected scaphoid fractures.

Aims

The use and variety of stemless humeral components in anatomical total shoulder arthroplasty (TSA) have proliferated since their advent in 2004. Early outcomes are reassuring but independent mid-term results are scarce. This independent study reports a consecutive series of 143 Eclipse stemless shoulder prostheses with a minimum five-year (5 to 10) follow-up.

Introduction: Periprosthetic fractures occurring during implantation of non-cemented Total Hip Arthroplasty (THA) are considered major surgical complications. As a shot-term disadvantage, patients are required to partially weight-bear. Additionally, high risks of stem migration and joint luxation can be assumed. On the other hand, in fear of fracture surgeons may undersize stems and subsequently trigger failure rates in THA. As the long-term consequences of Vancouver A and B1 fractures are not fully known, the goal of this study now was to analyze the postoperative performance of non-cemented THA with respect to perioperative fractures. Materials and Methods: Between 1997 and 2003 41 peri-operative hip fractures were monitored in 1216 primary Total Hip Arthroplasties using the non-cemented Bicon-tact THA stem. Pre-OP and after a follow-up period of 2,2 (+−3,1) years patients were examined clinically and radiographically. Investigation parameters were Harris-Hip-Scores, SF-36 scores, function score, hospitalization, implant survival /revisions and radiographic parameters (stem migration, trochanter migration, osteolysis, bone union, callus formation and bone quality). Fractures were graded using the Vancouver and Mont+Maar classifications. Patients were compared to a comparable collective of THA patients without perioperative fractures. Pooled data of both groups were compared using non-parametric Kruskal-Wallis tests. Results: Results showed a significant increase in Harris-Hip scores for all THA of 36 (+−17,7) points. There were no differences in function scores (2,3; score 1–6), postoperative pain (4,8; score 1–10), and time of hospitali-sation (21,3d; +−3,7 range, 14 – 32). The non-union rate was 13%, with 85% of trochanteric fractures showing migration. 47% of the Patients in the fracture group were instructed to maintain restricted weight bearing for 6 weeks. No Trendelenburg signs were observed in the fracture group. Stem migration of mean 0,6 cm (+−0,4) was observed in 13% of Vancouver A and B1 patients (6,4% of A, 20,1% of B1). Long-term cerclage wire failure was observed in 20%. Joint luxation was observed in 1 patient. No hips were revised during the follow-up period. Discussion: Follow-ups of perioperative fractures classes Vancouver A and B1 during non-cemented THA using the Bicontact stem show associations with stem migration, long-term stabilization implant failure and non-union. However, none of these observations seem to be influencing the overall THA performance and patient satisfaction. Specifically, complications commonly associated with perioperative primary prosthetic fractures as luxation and limping were not signifi-cant. At a short-term perspective, perioperative THA fractures prohibit early weight-bearing. However at a mid to long-term perspective, no disadvantages were apparent in comparison to primary THA without fracture complications

Aims

Open reduction and plate fixation (ORPF) for displaced proximal humerus fractures can achieve reliably good long-term outcomes. However, a minority of patients have persistent pain and stiffness after surgery and may benefit from open arthrolysis, subacromial decompression, and removal of metalwork (ADROM). The long-term results of ADROM remain unknown; we aimed to assess outcomes of patients undergoing this procedure for stiffness following ORPF, and assess predictors of poor outcome.

Aims

Controversy exists as to what should be considered a safe resection margin to minimize local recurrence in high-grade pelvic chondrosarcomas (CS). The aim of this study is to quantify what is a safe margin of resection for high-grade CS of the pelvis.