Introduction. Symptomatic hip dysplasia is often treated with periacetabular osteotomy (PAO). Studies investigating the effect of PAO have primarily focused on radiographic measurements, pain-related outcomes, and hip survival whereas evidence related to sport participation is limited. Methods. All patients in our institutional database were deemed eligible for this cohort study if they underwent PAO and had answered at least one question related to sport participation. Patients were asked if they were playing sport preoperatively, 6 months after PAO as well as 2, 5, 10, 15 and 20 years after. In addition, patients were asked if they were able to play their preferred sport, what type and at what level they were playing sport, and if surgery had improved their sport performance. Results. Among 2398 patients surveyed, 1926 (80%) were included and 56% were playing sport 6 months after PAO. This number was 61% two years after PAO, and remained around that for the following years, before dropping 15 years after PAO. Between 56% and 71% of patients felt that their sporting performance improved following PAO at the different time points. Between 39% (6 months after PAO) and 63% (15 years after PAO) were able to participate in their preferred sport. Conclusion. The majority of patients undergoing PAO due to hip dysplasia will return to, and maintain, sport after PAO. More than half of patients undergoing PAO believe that the surgery improved their sports performance, and long after the surgery more than half of patients undergoing PAO are able to play their preferred sport

Barriers to successful return to previous level of activity following Anterior Cruciate Ligament Recon-struction (ACLR) are multifactorial and recent research suggests that athletic performance deficits persist after completion of the rehabilitation course in a large percentage of patients. Thirty soccer athletes (26.9 ± 5.7 years old, male) with ACL injury were surgically treated with all-inside technique and semitendi-nosus tendon autograft. At 2 years from surgery, they were called back for clinical examination, self-reported psychological scores, and biomechanical outcomes (balance, strength, agility and velocity, and symmetry). Nonparametric statistical tests have been adopted for group comparisons in terms of age, concomitant presence of meniscus tear, injury on dominant leg, presence of knee laxity, presence of varus/valgus, body sides, and return to different levels of sports. Athletes with lower psychological scores showed lesser values in terms of power, resistance and neuromuscular activity as compared to the ones with good psychological scores that showed, instead, better self-reported outcomes (TLKS, CRSQ) and low fear of reinjury (TSK). In the athletes who had a functional deficit in at least one subtest, a safe return to sports could not have been recommended. Our findings confirmed that demographics, physical function, and psychological factors were related to playing the preinjury level sport at mean 2 years after surgery, sup-porting the notion that returning to sport after surgery is multifactorial. A strict qualitative and quantitative assessment of athletes’ status should be performed at different follow-ups after surgery to guarantee a safe and controlled RTP

Abstract

Abstract

Analysis of the morphology of the distal femur, and by extension of the femoral components in total knee arthroplasty (TKA), has largely been related to the aspect ratio, which represents the width of the femur. Little is known about variations in trapezoidicity (i.e. whether the femur is more rectangular or more trapezoidal). This study aimed to quantify additional morphological characteristics of the distal femur and identify anatomical features associated with higher risks of over- or under-sizing of components in TKA.

We analysed the shape of 114 arthritic knees at the time of primary TKA using the pre- operative CT scans. The aspect ratio and trapezoidicity ratio were quantified, and the post- operative prosthetic overhang was calculated. We compared the morphological characteristics with those of 12 TKA models.

There was significant variation in both the aspect ratio and trapezoidicity ratio between individuals. Femoral trapezoidicity was mostly due to an inward curve of the medial cortex. Overhang was correlated with the aspect ratio (with a greater chance of overhang in narrow femurs), trapezoidicity ratio (with a greater chance in trapezoidal femurs), and the tibio- femoral angle (with a greater chance in valgus knees).

This study shows that rectangular/trapezoidal variability of the distal femur cannot be ignored. Most of the femoral components which were tested appeared to be excessively rectangular when compared with the bony contours of the distal femur. These findings suggest that the design of TKA should be more concerned with matching the trapezoidal/ rectangular shape of the native femur.

This study of collegiate basketball players evaluated change over time (COT) in ultrasound shear wave (SW) elastography metrics across the basketball season, and correlated to morphologic changes on conventional ultrasound imaging, and VISA-P scores. In eleven male collegiate basketball players (mean age 19, age range 18–21), patella tendon (PT) ultrasound and SW elastography of both knees were performed at pre-season and post-season time points, and players reported their VISA-P scores throughout the season. Patella tendinopathy grade and SW metrics were correlated to VISA-P scores using Spearman correlation coefficients. Paired t-test was used to assess differences in mean SW metrics at pre-and post-season timepoints, accounting for leg dominance. 6 of 11 players (54.5%) had baseline patella tendinopathy on ultrasound progressing in 4 players. The mean change in VISA-P score was 15.18 (+/−8.55). No significant correlation was seen between ultrasound grades of tendinopathy and VISA-P. Pre-season SW velocities did not significantly correlate with baseline VISA-P scores. Post-season SW values and SW COT demonstrated strong correlation with change in VISA-P score in dominant and non-dominant knees. Although not statistically significant, there was a trend towards higher SW velocity for tendinopathy in both dominant and non-dominant knees at both study visits. SW metrics of the PT correlated to change in VISA-P scores in the dominant and non-dominant knees, whereas conventional ultrasound grades of patella tendinopathy did not. There was a trend towards higher SW velocities in patella tendinopathy which may indicate detection of change in intrinsic tissue stiffness.

Hop tests are used to determine return to sports after ACL reconstruction. They mostly measure distance and symmetry but do not assess kinematics and kinetics. Recently, biomechanical evaluations have been incorporated into these functional jump tests for the better assessment of return to sport. We assessed the sagittal plane range of motion (ROM) of the knee, the deviation axis of rotation (DAOR), and the vertical ground reaction force (vGRF) normalized to body weight in nine healthy participants during the single leg (SLH) and crossover hop tests (COHT). Participants' leg lengths were measured. Jumping distances were marked in the test area as being 4/5 of the leg length. Four sensors were placed on the thighs, the legs and the feet. These body parts were handled as a single rigid body. Eight 480 Hz cameras were used to capture the movements of these rigid bodies. vGRF at landing were measured using a force plate (Bertec, Inc, USA). The ROM of the knee joint and the DAOR were obtained from kinematic data. Participants' joint kinematics metrics were similar in within-subjects statistical tests for SLH and COHT. We therefore asked whether the repeated vGRF normalized to body weight will be similar in both legs during these jumps. Joint kinematics metrics however were different in between subjects indicating the existence of a personalized jumping strategy. These hop tests can be recorded at the beginning of the training season for each individual, which can establish a comparative evaluation database for prospective lower extremity injury recovery and return to sport after ACL injury

Introduction. Patellar tendinopathy is a highly prevalent clinical diagnosis supported by ultrasound changes. Numerous interventions are targeted at improving both symptoms and structure of dysfunctional tendons, however little is known of the diagnostic value in a changing ultrasound profile whilst patient reported outcome measures determine recovery. The aim of this study was to assess if change in ultrasound measure is congruent with change in Victorian Institute of Sport Assessment – Patella (VISA-P) score and therefore indicates the use of using ultrasound to assess patellar tendinopathy during symptom change. Method. Four databases (PubMed, Web of Science, Embase, Cinahl) were search in January 2014. Studies selected contained ultrasound and VISA-P scores from ≥ 2 type points. All included studies were quality assessed depending on type and available data underwent meta-analysis. Result. 10 papers of varying study type, of limited to high quality, were synthesised. Meta-analysis indicated that change in ultrasound measure was not congruent with change in VISA-P score. Conclusion. The variation in study quality, along with significant heterogeneity of ultrasound measure outcomes and reporting may influence the congruency of the data, but the association between gradual structure change and varying vascularity with pain or function is questionable throughout tendinopathy literature

To investigate changes in quadriceps and hamstrings muscle groups during sustained isokinetic knee flexion and extension. 125 paediatric participants (45 males and 80 females, mean age 14.2 years) were divided into two groups: participants with a confirmed ACL tear (ACLi, n = 64), and puberty- and activity-level matched control participants with no prior history of knee injuries (CON, n = 61). Participants completed a series of 44 repetitions of isokinetic knee flexion and extension at 90 deg/ sec using a Biodex dynamometer (Biodex Medical Systems Inc, Shirley, New York). Surface EMG sensors (Delsys Incorporated, Natick, MA) simultaneously recorded the quadriceps and hamstring activations. Muscle function was assessed as the change in quadriceps activation and extension torque were calculated using the percent difference between the mean of the first five trials, and the mean of the last five trials. ACLi participants had significantly higher percent change in quadriceps activation for both healthy and injured legs, in comparison to CON dominant leg. As such, the healthy leg of the ACLi participants is activating significantly more than their health matched controls, while also demonstrating reduced muscular endurance (less torque in later repetitions). Therefore, we conclude that the non-injured limb of the ACLi participant is not performing as a healthy limb. Since return to activity clearance following ACLi implies return to sport against age- and activity matched opponents, clearing young athletes based on the non-injured contralateral limb may put them at greater risk of reinjury

Primary malignant bone and soft tissue tumours often occur in the lower extremities of active individuals including children, teenagers and young adults. Survivors routinely face long-term physical disability. Participation in sports is particularly important for active young people but the impact of sarcoma treatment is not widely recognised and clinicians may be unable to provide objective advice about returning to sports. We aimed to identify and summarise the current evidence for involvement in sports following treatment of lower limb primary malignant bone and soft tissue tumours. A comprehensive search strategy was used to identify relevant studies combining the main concepts of interest: (1) Bone/Soft Tissue Tumour, (2) Lower Limb, (3) Surgical Interventions and (4) Sports. Studies were selected according to eligibility criteria with the consensus of three authors. Customised data extraction and quality assessment tools were used. 22 studies were selected, published between 1985 – 2020, and comprising 1005 patients. Fifteen studies with data on return to sports including 705 participants of which 412 (58.4%) returned to some form of sport at a mean follow-up period of 7.6 years. Four studies directly compared limb sparing and amputation; none of these were able to identify a difference in sports participation or ability. Return to sports is important for patients treated for musculoskeletal tumours, however, there is insufficient published research to provide good information and support for patients. Future prospective studies are needed to collect better pre and post-treatment data at multiple time intervals and validated clinical and patient sports participation outcomes such as type of sports participation, level and frequency and a validated sports specific outcome score, such as UCLA assessment. In particular, more comparison between limb sparing and amputation would be welcome

Though retear rates following rotator cuff repair are well established, we set out to review current literature to determine when early retears occurred (defined as <12m following surgery), and examine which pre- and post-operative variables might affect outcome. Pubmed, Medline, and CINAHL were searched for literature published from 2011 to 2021 using specific search terms. The inclusion criteria were studies reporting retear rates within 12 months of initial surgical repair. Exclusionary criteria were studies that included partial thickness tears, and studies that did not use imaging modalities within 12 months to assess for retears. PRISMA guidelines were followed, identifying a total of 10 papers. A combined total of 3372 shoulders included (Mean age 56 −67 years). The most common modality used to identify early retears were ultrasound scan and MRI. 6 of the 10 studies completed imaging at 0-3 months, 6 studies imaged at 3-6 months and 6 studies imaged at 6-12 months. Across all studies, there was a 17% early retear rate (574 patients). Of these, 13% occurred by 3 months, whilst the peak for retears occurred at 3-6 months (82%) and 5% occurred at 6-12 months. The risk of retear was higher in larger tears and extensive tendon degeneration. All studies apart from one documented a return to work/sport at 6 months post-operatively. Postoperative rehabilitation does not appear to alter retear rate, although data is limited with only 1 of 10 studies allowing active range of movement before 6 weeks. Retorn tendons had poorer functional outcomes compared to intact tendons at 12m following initial repair. The majority of early retears occur at 3-6 months and this time period should be prioritised both in rehabilitation protocols and future research. Age, tear size, and tendon degeneration were found to influence likelihood of early retears

Vacuum orthoses are being applied in the care of patients with foot and lower leg conditions, as ankle fractures or sprains. The lower leg is protected and immobilized, which increases mobility. Due to the design, the orthoses lead to a difference in leg length, i.e. the side with the orthosis becomes longer, which changes the gait kinematics. To prevent or mitigate the unfavourable effects of altered gait kinematics, leg length-evening devices (shoe lifts) are offered that are worn under the shoe on the healthy side. Our aim was to evaluate the effect of such a device on the normality of gait kinematics. Gait analysis was conducted with 63 adult, healthy volunteers having signed an informed consent form that were asked to walk on a treadmill at a speed of 4.5km/h in three different conditions:. barefoot - as reference for establishing the normality score baseline. with a vacuum orthosis (VACOPed, OPED GmbH, Germany) and a sport shoe. with a vacuum orthosis and a shoe lift (EVENup, OPED GmbH, Germany). Data was sampled using the gait analysis system MCU 200 (LaiTronic GmbH, Austria). The positions of the joint markers were exported from the software and evaluated for the joint angles during the gait cycle using custom software (implemented in DIAdem 2017, National Instruments). A normality score using a modification of the Gait Profile Score (GPS) was calculated in every 1%-interval of the gait cycle and evaluated with a Wilcoxon signed rank test. The GPS value was reduced by 0.33° (0.66°) (median and IQR) while wearing the shoe lift. The effect was statistically significant, and very large (W = 1535.00, p < .001; r (rank biserial) = 0.52, 95% CI [0.29, 0.70]). The significant reduction of the GPS value indicates a more normal gait kinematics while using the leg length-evening device on the contralateral shoe. This rather simple and inexpensive device thus might improve patient comfort and balance while using the vacuum orthoses

To investigate differences in the drop vertical jump height in female adolescents with an ACL injury and healthy controls and the contribution of each limb in this task. Forty female adolescents with an ACL injury (ACLi, 15.2 ± 1.4 yrs, 164.6 ± 6.0 cm, 63.1 ± 10.0 kg) and thirty-nine uninjured (CON, 13.2 ± 1.7 yrs, 161.7 ± 8.0 cm, 50.6 ± 11.0 kg) were included in this study. A 10-camera infrared motion analysis system (Vicon, Nexus, Oxford, UK) tracked pelvis, thigh, shank, and foot kinematics at 200Hz, while the participants performed 3 trials of double-legged drop vertical jumps (DVJ) on two force plates (Bertec Corp., Columbus, USA) sampled at 2000Hz.The maximum jump height normalised by dominant leg length was compared between groups using independent samples t-test. The maximum vertical ground reaction force (GRFz) and sagittal ankle, knee and hip velocities before take-off were compared between limbs in both groups, using paired samples t-test. The normalised jump height was 11% lower in the ACLi than in the CON (MD=0.04 cm, p=0.020). In the ACLi, the maximum GRFz (MD=46.17N) and the maximum velocities of ankle plantar flexion (MD=79.83°/s), knee extension (MD=85.80°/s), and hip extension (MD=36.08°/s) were greater in the non-injured limb, compared to the injured limb. No differences between limbs were found in the CON. ACL injured female adolescents jump lower than the healthy controls and have greater contribution of their non-injured limb, compared to their injured limb, in the DVJ task. Clinicians should investigate differences in the contribution between limbs during double-legged drop vertical jump when assessing patients with an ACL injury, as this could help identify asymmetries, and potentially improve treatment, criteria used to clear athletes to sport, and re-injury prevention

Osteochondral lesions (OCLs) of the talus are a challenging and increasingly recognized problem in chronic ankle pain. Many novel techniques exist to attempt to treat this challenging entity. Difficulties associated with treating OCLs include lesion location, size, chronicity and problems associated with potential graft harvest sites. Matrix associated stem cell transplantation (MAST) is one such treatment described for larger lesions >15mm. 2. or failed alternative therapies. This cohort study describes a 5 year review of the outcomes of talar lesions treated with MAST. A review of all patients treated with MAST by a single surgeon was conducted. Pre-operative radiographs, MRIs and FAOS outcome questionnaire scores were conducted. Intraoperative classification was conducted to correlate with imaging. Post-operative outcomes included FAOS scores, return to sport, revision surgery/failure of treatment and progression to arthritis/fusion surgery. 32 patients were identified in this cohort. There were 10 females, 22 males, with an average age of 35. 01. 73% had returned and continued playing active sport. 23 patients underwent MAST in the setting of a failed previous operative attempt, with just 9 having MAST as a first option. 9 patients out of 32 had a further procedure. Two patients had a further treatment directed at their OCL. Two patients had a fusion, 2 had a cheilectomy at > 4 years for impingement, one had a debridement of their anterolateral gutter, one had debridement for arthrofibrosis, one patient had a re alignment calcaneal osteotomy with debridement of their posterior tibial tendon. MAST has demonstrated positive results in lesions which prove challenging to treat, even in a “failed microfracture” cohort

Head collisions in sport can result in catastrophic cervical spine injuries. Musculo-skeletal (MSK) modelling can help analyse the relationship between players' motion, external loading and internal stresses that lead to injury. However, the literature lacks sport specific MSK models. In automotive research the intervertebral disc behaviour has been represented as viscoelastic elements (“bushing”), whose stiffness and damping parameters are often estimated under quasi-static conditions and may lack validity in dynamic impacts. The aim of this study was to develop a validated cervical spine model for axial impacts for future use in the analysis of head-first rugby collisions. A drop test rig was used to replicate a sub-catastrophic axial head impact. A load of 80 N from 0.5 m was applied to the cranial aspect of a C2-C6 porcine spinal specimen mounted in the neutral position. The 3D motion of C3-C5 vertebras (4 kHz) and the cranial axial load (1 MHz) were measured via motion capture (Qualysis, Sweden) and a uniaxial load cell (RDP Electronics Ltd, UK). Specimen specific models were created in NMSBuilder and OpenSim after the vertebrae geometries were obtained from the segmentation of micro-CT images of the specimens. The compressive viscoelastic properties of four vertebral joints (C2-C3 through to C5-C6) were optimised via a Genetic Algorithm (MATLAB v2016b, The Mathworks Inc) to minimise tracking errors. The optimisation converged to a solution of 140–49000 kN/m and 2000–8000 Ns/m for stiffness and damping respectively (RMSE=5.1 mm). Simulated joint displacements ranged between 0.09 – 1.75 mm compared to experimental 0.1 – 0.8 mm. Optimal bushing parameters were higher than previously reported values measured through quasi-static testing. Higher stiffness and damping values could be explained by the higher-dynamics nature of the event analysed related to a different part of the non-linear intervertebral disc load-displacement curve

Background. Return to sports after anterior cruciate ligament reconstruction (ACLR) is multifactorial and rotational stability is one of the main concerns. Anterolateral ligament reconstruction (ALLR) has been recommended to enhance rotational stability. Purpose. To assess the effect of ALLR on return to sports. Study Design. Retrospective comparative cohort study;. Level of evidence: III. Methods. A total of 68 patients who underwent ACLR after acute ACL injury between 2015 and 2018 with a follow-up of at least 24 months were enrolled in the study. Patients with isolated ACLR (group ALL(-), n=41) were compared to patients with ACLR+ALLR (group ALL(+), n=27) in regard to subjective knee assessment via Tegner activity scale, Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale, Knee Documentation Committee (IKDC) form and Lysholm score. All tests were performed before the surgery, at 6 months and 24 months postoperatively. Results. Mean follow-up was 29.7±2.9 months for group ALL(-) and 31.6±3.0 for ALL(+) (p=0.587). Tegner, ACL-RSI and IKDC scores at last follow-up were significantly better in ALL(+) compared to ALL(-). There were no significant differences in isokinetic extensor strength and single-leg hop test results between the groups. 40 (97.6%) patients in ALL(-) and 27 (100%) in ALL(+) had a grade 2 or 3 pivot shift (p=0.812) preoperatively. Postoperatively, 28 (68.3%) patients in ALL(-) and 25 (92.6%) patients in ALL(+) had a negative pivot shift (p<0.001). 2 (5.9%) patients in ALL(-) and 1 (3.7%) patient in ALL(+) needed ACLR revision due to traumatic re-injury (p=0.165). There was no significant difference in the rate of return to any sports activity (87.8% in ALL(-) vs 88.9% in ALL(+); p=0.532), but ALL(+) showed a higher rate of return to the same level of sports activity (55.6%) than group ALL(-) (31.7%) (p=0.012). Conclusion. ACLR combined with ALLR provided a significantly higher rate of return to the same level sports activity than ACLR alone, probably due to enhanced rotational stability

The purpose of this study was to compare the outcomes of arthroscopic unilateral surgery and simultaneous bilateral surgery for posterior ankle impingement syndrome (PAIS) in athletes and to evaluate the usefulness of simultaneous bilateral surgery. A total 48 hindfeet of 41 athletes (14 hindfeet of 14 males, 34 hindfeet of 27 females) who underwent arthroscopic surgery for PAIS were studied. Japanese society for surgery of the foot (JSSF) score and visual analogue scale (VAS) were compared before and after surgery, using Wilcoxon signed-rank test. The operation time and the time to return to sports activity were compared in 10 hindfeet of 5 patients who underwent simultaneous bilateral surgery and 38 hindfeet of 36 patients who underwent unilateral surgery, using Wilcoxon rank sum test. Classic ballet was the most common type of sport that caused PAIS (59%, 24/41 athletes). Soccer (10%, 4/41 athletes), baseball (10%, 4/41 athletes), badminton (5%, 2/41 athletes), volleyball (5%, 2/41 athletes), and athletics (5%, 2/41 athletes) followed. The JSSF score improved significantly from 72.7 preoperatively to 98.9 postoperatively in unilateral surgery, and significantly improved from 75.2 preoperatively to 99.0 postoperatively in simultaneous bilateral surgery. VAS significantly decreased from 64.7 preoperatively to 4.8 postoperatively in unilateral surgery, and significantly decreased from 72.7 preoperatively to 1.0 postoperatively in simultaneous bilateral surgery. The operating time was 53.7 minutes on average for unilateral surgery and 101.0 minutes for simultaneous bilateral surgery, significantly longer in bilateral simultaneous surgery. The mean time to return to sports activity was 4.8 weeks for unilateral surgery and 9.6 weeks for simultaneous bilateral surgery, significantly longer in simultaneous bilateral surgery. Both unilateral and simultaneous bilateral surgeries for PAIS in athletes were useful. It should be noted that the operating time and the time to return to sports will be longer. However, considering the 2 times hospitalizations and 2 times surgeries, simultaneous bilateral surgery is one of the treatment options for PAIS

The reintroduction of hip resurfacing has raised the possibility of whether it could offer a better outcome in sporting and work activity after surgery compared to total hip replacement. Questionnaires were analysed from 125 total hip replacement (THR) and 108 hip resurfacing (HR) patients regarding participation in sport in the year after their surgery and returning to work they were employed at prior to their surgery. The two groups had similar average age (61 vs 60) and pre-operative Oxford hip scores (41 vs 38). Seventy-one of one-hundred and twenty-five THR patients compared to 76/108 HR patients participated in sporting activity in the year after their surgery. When including only patients that played sport before their surgery 54/75 THR and 66/83 HR patients returned to same sporting activity level after their surgery. Of the patients that worked before surgery 35/44 THR patients compared to 70/74 HR patients returned work to after their surgery. There is significant difference quantity of patients participating in sporting activity after HR and THR (fishers exact test, p value=0.04). However there is no significant difference in quantity of patients returning to sporting activity after HR or THR including only patients that played sport before their surgery (fishers exact test, p value=0.35). There is a significant difference in the quantity of patients returning to work activity after HR and THR (fishers exact test, p value= 0.02). HR has a better outcome in patients participating in sport after surgery compared to THR however there is no benefit for patients that are active pre-operatively. More patients return to work after HR than THR

Anterior cruciate ligament injury is the most common and economically costly sport injuries, frequently requiring expensive surgery and rehabilitation. Post-operative knee septic arthritis represents a serious complication with an incidence rate between 0.14% and 1.7%. A common practice to avoid septic arthritis is the “vancomycin wrap”, consisting in the soaking of the graft for 10–15 minutes within a sterile gauze swab previously saturated with 5 mg/mL vancomycin. Even though several studies have been conducted to investigate vancomycin toxicity on different musculoskeletal tissues or cells, little is known about the effect of such antimicrobial on tendon-derived cells. The aim of this study was to determine the in vitro toxicity of different concentrations of vancomycin at different time points on human primary tenocytes (hTCs). hTCs were isolated from hamstring grafts of patients undergoing anterior cruciate ligament reconstruction. After expansion, cells were treated with different concentrations of vancomycin (2.5, 5, 10, 25, 50 and 100 mg/mL) for 10, 15, 30 and 60 minutes. In vitro toxicity was evaluated measuring: metabolic activity through the reduction of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT Assay); cytotoxicity (Live/Dead assay); and cell apoptosis (Annexin V apoptosis kit). The metabolic activity of hTCs was affected by vancomycin treatment starting from 10 mg/mL at all time points (p < 0.05) and dropped down at 100 mg/mL at all time points (0.05 < p < 0.001). Cells viability resulted to be unaffected only by 2.5 mg/mL vancomycin at all time points. Vancomycin resulted to be cytotoxic starting from 10 mg/mL after 15 minutes of treatment and at all higher concentrations under study at all time points. Cells died when treated with vancomycin concentrations higher than 5 mg/mL but not through apoptosis, as confirmed by negative staining for Annexin V. In our experimental conditions, vancomycin resulted to be toxic on hTCs at concentrations higher than 5 mg/mL. The use of this antibiotic on tendons to prevent infections could be useful and safe for resident cells if used at a concentration of 2.5 mg/mL up to 1 hour of treatment

Total hip arthroplasty (THA) is one of the most successful surgery. However, patients' expectations have increased over the last two decades in regards to hip function after joint replacement, the patients assume to return their daily and sport activities without major limitations. This presentation will examine the effect of surgical approaches and implant designs as well as rehabilitation protocol on the clinical and biomechanical outcomes after THA. The new implant designs for THA aim to improve joint function whereas the surgical approaches intend to reduce muscle damage to regain muscle strength. One important determinant measured from gait analysis is the hip abduction moment as the abductors play a key role in stabilizing the pelvis in the frontal plane, particularly in phases of transition, such as the single leg stance in walking or stair climbing. This showed that muscle strength needs to be preserved. To minimize the risk of hip joint instability, a strong focus of implant development has been carried out. To illustrate this important concept within the context of gait analysis, I will present two studies that examine the influence of surgical approach and biomechanical reconstruction; and the second, is a prospective RCT comparing a dual mobility implant to a standard total hip replacement