Load transfer through orthopaedic joint implants is poorly understood. The longer-term outcomes of these implants are just starting to be studied, making it imperative to monitor contact loads across the entire joint implant interface to elucidate the force transmission and distribution mechanisms exhibited by these implants in service. This study proposes and demonstrates the design, implementation, and characterization of a 3D-printed smart polymer sensor array using conductive polyaniline (PANI) structures embedded within a polymeric parent phase. The piezoresistive characteristics of PANI were studied to characterize the sensing behaviours inherent to these embedded pressure sensor arrays. PANI's stable response to a continuous load, its stability throughout loading and unloading cycles, and its repeatable and linear response to incremental loading cycles together with the accuracy of these measurements were investigated. It is demonstrated that this specially developed multi-material additive manufacturing process for polyaniline is an attractive approach for the fabrication of implant components having embedded smart-polymer sensors for the measurement and analysis of joint loads in orthopaedic implants.

There was no significant difference in bacterial adhesion between the 3 bone graft types tested, regardless of the bacterial strain used (p > 0.22). After 72 hours of culture, there was no significant difference between the Fresh and Frozen bone groups, while the number of CFU in the Decellularised group was significantly lower (p < 0.01), averaging -0.72 +/- 0.08 lg, -0.20 +/- 0.01 lg and -0.78 +/- 0.48 lg with S. epidermidis, S. aureus and E. coli respectively. Absolute values differences are low, and considering fresh bone (equivalent to autograft) as the gold standard due to its low infection rates in clinical studies, we can conclude that adhesion and biolfilm development characteristics are similar between Fresh, Frozen and Decellularised bone grafts..

The majority of contemporary total hip arthroplasty (THA) implants are constructed from Ti-alloys, which are generally believed to generate fewer adverse local tissue reactions (ALTR) compared to CoCr-alloys. This study presents a case of unusual primary THA failure where a substantial release of Ti-alloy debris was observed. A 52-year-old active male underwent THA after posttraumatic aseptic necrosis of the femoral head in 2006. Seventeen years after the procedure, the patient presented with groin pain and restricted range of motion. X-rays revealed protrusion of the alumina ceramic head through the Ti6Al4V acetabular cup. Trace element analysis indicated significantly elevated levels of serum Ti, Al and V. CT and MRI confirmed Ti-alloy cup failure and severe ALTR. During revision surgery, the worn-out ceramic head was in direct contact with the acetabular cup, having protruded through the central hole it created over time. Histological analysis of tissue samples showed wear-induced synovitis with areas of multinucleated foreign-body giant cells and accumulation of numerous metal particles but no acute inflammatory response. Six months after the revision THA, the patient has experienced favourable outcomes. This case provides an instructive illustration for studying the consequences of substantial release of Ti-alloy debris from orthopaedic implants.

This observational study aims to depict the impact of gender and socio-economic issues on the health status of Italian Orthopaedic patients during the COVID-19 lockdown. An Ad Hoc ques-tionnaire was developed and online administered. The following data were extracted from the questionnaire: age, body mass index (BMI), education level, distance from hospital, orthopaedic disease, concomitant medical comorbidities, living status (with/without cohabitants) and physical activity level (according to Tegner Activity Scale). The impact of the COVID-19 lockdown was studied analyzing differences related to the above-mentioned parameters. A significant increase of the call number to general practitioner and to the orthopaedic surgeon was observed during the COVID-lockdown, especially in patients with higher education level. Nonetheless, a reduced compliance in drugs assumption was observed in patients with higher education level during lockdown (p=0.007). Almost all the analyzed items were significantly in-fluenced by the distance between patient’s domicile and the nearest hospital. However, no sig-nificant differences were observed comparing pre-COVID to COVID lockdown. In the present study patients’ gender and education level revealed a significant impact on the social behavior during the COVID lockdown, compared with the pre-COVID period.

Objectives: The aim of this study was to compare the performance of the EQ-5D-Y-3L (Y-3L) and the expanded five level version, the EQ-5D-Y-5L (Y-5L). Methods: Children/adolescents with an acute or chronic health condition and from the general population completed the Y-5L and Y-3L self-report questionnaires. Performance of the Y-5L and Y-3L was determined by comparing feasibility, redistribution of dimension responses, discriminatory power, validity, and test-retest reliability. Results. Five hundred and fifty children/adolescents completed baseline measures and 173 completed repeat measures. The ceiling effect decreased by 15% from the Y-3L to Y-5L. Informativity of dimensions improved by 0.094 on the Y-5L. There was a range of 4-9% inconsistent responses moving from the Y-3L to Y-5L. Convergent validity of the Visual Analogue Scale (VAS) and Y-3L, Y-5L dimensions was similar, weak to moderate (r_s range: 0.18 – 0.38) but similar and strong on paired Y-3L and Y-5L dimensions: Kendall Tau B (range 0.69 – 0.80) and Gamma (range 0.92 – 0.98). The Y-5L and Y-3L showed moderate to substantial agreement for test-retest reliability across dimensions and VAS scores in stable chronic health conditions and fair agreement for the general population. Conclusion: The EQ-5D-Y-5L is a valid, reliable extension of the Y-3L for children/adolescents across health conditions and healthy children/adolescents. The expanded levels reduced the ceiling effect. The relative informativity of report across dimensions increased on the Y-5L compared to the Y-3L with retention of the evenness of reporting. The convergent validity and test-retest reliability of the Y-5L was comparable to the Y-3L.

The rabbit is a popular animal model for human biomechanical research involving surgery at the hind limb. General anesthesia in rabbits is associated with significantly higher mortality rates than in dogs and cats. In addition, as prey animals, rabbits tend to mask signs of pain, making early detection particularly difficult. Regional anaesthesia, as an adjunct to general anaesthesia, may markedly reduce the need for systemic anaesthetic and analgesic drugs, limiting their associated side effects. In other species, a block of the sciatic (ScN) and the femoral nerves (FN) is usually applied in patients undergoing hind limb surgery. In phase 1 of this study, the ScN and the FN have been localized and an appropriate approach under sonographic guidance has been evaluated. In phase 2, a mixture of methylene blue and lidocaine have been administered to the ScN and the FN in 10 cadavers (20 hind limbs). Staining of the nerves was evaluated by dissection. Ultrasonographically, the ScN appeared as a binocular structure surrounded by a hyperechoic rim. The FN appeared as a hypoechoic structure in the dorsal part of the IPM, becoming hyperechoic/honey-comb-like in the ventral part. Both nerves could be successfully stained in all animals over a median length of 2.3 cm which was considered effective. This technique allows a feasible and accurate access to block of the ScN and the FN and may lead to successful analgesia in rabbits undergoing hind limb surgery.