Introduction. The pathophysiology of osteonecrosis of femoral head (ONFH) is uncertain for most cases with speculation of vascular impairment and changes in cell biology due to multi-factorial etiologies including corticosteroid, alcohol, smoking, trauma, radiation or caisson disease and genetic. Extracorporeal shockwave therapy (ESWT) began with an incidental observation of osteoblastic response pattern during animal studies in the mid-1980 that generated an interest in the application of ESWT to musculoskeletal disorders. The mechanism of shockwave therapy is not fully understood but several reports showed better clinical outcomes and promoted bone remodelling and regeneration effect of the femoral head after ESWT in ONFH. Therefore, we compared the clinical results of the use of extracorporeal shock wave therapy (ESWT) on the patients with ONFH in radiographic staging. Methods. We evaluated 24 patients with 32 hip joints diagnosed ONFH treated with ESWT from 1993 to 2012. Average follow-up period was 27 months, and patients were average 47.8 aged. Association Research Circulation Osseous (ARCO) staging system was used to grade radiographic stage before treatment. All the patients were divided to two groups; group 1 (ARCO stage I,II), group 2 (ARCO stage III). Comparative analysis was done between two groups with visual analogue scale (VAS) score and Harris hip score (HHS) at pre-treatment, 3, 6, 12 and 24 months after treatments. The failure was defined when radiographic stage was progressed or arthroplasty surgery was needed due to clinical exacerbation. Results. Two groups showed all clinical improvements with VAS scoring at final follow-up (group 1: mean 6.3 to 1.6, p < 0.001; group 2: mean 7.1 to 3.3, p < 0.001). With HHS, group 1 showed a significant improvement from 64.4 to 95.4 (p < 0.001), while no significance in group 2 (p = 0.280). At final-follow-up, 3 hips of group 1 and 1 hip of group 2 showed radiographic improvement, but 2 patients were performed total hip arthroplasty due to persistent pain and dysfunction. Discussion and Conclusion. ESWT could be considered as an alternative option before surgical treatment in patients not only with early stage of ONFH but also with mid stage

Paediatric bone and joint infections remain common in low- and middle-income countries (LMICs). We aimed to determine the complication rate and incidence of disseminated infection in paediatric bone and joint infections in an LMIC setting. Secondly, we aimed to elucidate factors associated with complications and disseminated disease. We retrospectively reviewed our database for children that presented with bone and joint infections between September 2015 and March 2019. Data were extracted to identify factors that were associated with development of complications and disseminated infection. We analysed 49 children. The median age at presentation was 6 years (range 1 month to 12 years). Locally advanced disease was present in 13 children (27%). The remaining 36 children were evenly divided (18/49 each, 37%) between isolated AHOM and SA, respectively. Disseminated disease was present in 16 children (33%) and was associated with locally advanced disease, an increase in number of surgeries and an increased length of stay. Twenty-six complications were documented in 22 (45%) children. Chronic osteomyelitis developed in 15/49 (31%) cases, growth arrest in 5/49 (10%), and pathological fracture, DVT and septic shock in 2/49 (4%) each. Complicated disease was associated with locally advanced disease, a higher number of surgeries, disseminated disease and an increased length of stay. Sixty five percent of cases cultured Staphylococcus aureus, while 25% (12/49) were culture negative. The median time from admission to surgery was one day, and the median time from onset of symptoms to surgery was seven days. We found a high complication rate. One third of patients had locally advanced disease, and this was associated with the development of complications and disseminated disease. Further studies are needed to be able to predict which children will have poor outcomes

Aim. The aim of our study was to analyze putative genes for virulence factors of Cutibacterium isolates obtained from implant-associated infections. Methods. We analyzed 64 isolates of Cutibacterium spp. (C. acnes (53/64), C. avidum (6/64), C. granulosum (4/64), C. namnetense (1/64)) using NextSeq 550 (Illumina, San Diego, CA, USA) and performed genomic analysis of 24 genes associated with virulence factors (VFs) of C. acnes previously reported in the literature. Most isolates were obtained from implant-associated infections (IAI) between 2012–2021 at the Institute of Microbiology and Immunology, Faculty of Medicine, Ljubljana. Additionally, we included the first C. namnetense isolated in our laboratory from surgical site infection. Results. C. acnes and C. namnetense have the highest number of VFs among those examined. The VFs gntK (shikimate kinase) and HYL-IB / II (hyaluronate lyase) are absent in phylotype IA. 1. (sequence types (ST) A, C, D according to the SLST scheme). Repressor gene of porphyrin synthesis, deoR is present in all Cutibacterium spp. isolates. The phylotypes II and IB show a similar distribution of VFs, with the presence of the VFs rcsB (compound for biofilm formation) and HYL-IA (hyaluronate lyase), which are absent in other C. acnes phylotypes and other Cutibacterium spp. In phylotypes IA. 1. and IB, the sequence of genes encoding VFs dsA1 and dsA2 does not have 100% genomic coverage, possibly indicating homologs between species. The isolates of C. acnes and C. namnetense possess all three CAMP (1,2,4) factors, which are not detected in other Cutibacterium spp. However, further analysis revealed species-specific CAMP factors in C. avidum and C. granulosum. Both species also have similar other genes for VFs, mainly encoding heat shock proteins and lipases, while VFs related to biofilm production are mostly absent (rcsB, ytpA). Conclusion. We found several differences in the distribution of VFs among Cutibacterium spp. isolated from IAI

Aim. A novel anti-infective biopolymer implant coating was developed to prevent bacterial biofilm formation and allow on-demand burst release of anti-infective silver (Ag) into the surrounding of the implant at any time after surgery via focused high-energy extracorporeal shock waves (fhESW). Method. A semi-crystalline Poly-L-lactic acid (PLLA) was loaded with homogeneously dissolved silver (Ag) applied onto Ti6Al4V discs. A fibroblast WST-1 assay was performed to ensure adequate biocompatibility of the Ag concentration at 6%. The prevention of early biofilm formation was investigated in a biofilm model with Staphylococcus epidermidis RP62A after incubation for 24 hours via quantitative bacteriology. In addition, the effect of released Ag after fhESW (Storz DUOLITH SD1: 4000 impulses, 1,24 mJ/mm. 2. , 3Hz, 162J) was assessed via optical density of bacterial cultures (Escherichia coli TG1, Staphylococcus epidermidis RP62A, Staphylococcus aureus 6850) and compared to an established electroplated silver coating. The amount of released Ag after the application of different intensities of fhESW was measured and compared to a control group without fhESW via graphite furnace atomic absorption spectrometry (GF-AAS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Results. The coating with 6% Ag reduced Staphylococcus epidermidis biofilm formation by 99.7% (mean±SD: 2.1×10^5 ± 3,9×10^5 CFU/µL) compared to uncoated controls (6.8×10^7 ± 4.9×10^7 CFU/µL); (p=0.0001). After applying fhESW the commercially available electroplated silver coating did not prevent the growth of all tested bacterial strains. Bacterial growth is delayed with 4% Ag and completely inhibited with 6% Ag in the novel coating, except for a small increase of S. aureus after 17 hours. SEM and EDS confirmed a local disruption of the coating after fhESW. Conclusions. This novel anti-infective implant coating has the potential to prevent bacterial biofilm formation. The on-demand burst release of silver via fhESW could be an adjunctive in the treatment of implant related infection and is of particular interest in the concept of single stage revision surgery

A retrospective case control study of all rehabilitated patients who suffered amputations of the lower extremity by sepsis was performed in the HELIOS centre of rehabilitation for amputees, Bad Berleburg, Germany. This study examines patients who had undertaken an amputation of the lower extremity caused by severe sepsis and septic shock. Methods: Case control study. The clinical reports of 448 patients with amputations of the lower extremity clinically rehabilitated from 2010 to 2013 were systematically and statistically evaluated. Sepsis is classified in 4 categories: SIRS, sepsis, severe sepsis and septic shock. Epidemiology: The mean age of the amputees was 61.33 years, with 25 men and 11 women. Marital status: 16 patients are married (44.44%), 7 divorced, 5 widowed, 7 unmarried, 1 unknown. 24 patients are retired (66.67%). School-leaving qualifications: 22 elementary school (61.11%), 8 secondary school, 1 high school, 5 unknown. Health insurance: AOK 10 patients (27.77%), BEK 7 patients (19.44%), pension insurance 9 patients (25.0%). The medial time of hospitalization in the clinic for rehabilitation of the amputated patients suffering sepsis was 27.23 days. Results: 36 patients, – 8.03 % of all – with 39 amputations, suffered a loss of the lower extremity caused by severe sepsis and septic shock: 1 patient suffered an exarticulation of both hips, 20 patients suffered a transfemoral amputation (1 patient had a transfemoral amputation of both legs), 17 patients lost their leg by transtibial amputation (1 patient had a transtibial amputation of both legs). 13 patients presented a sepsis by MRSA (multiresistant Staph. aureus 36.11%), 8 patients with MSSA (multisensible Staph. aureus), 4 patients with multiresistant Acinetobacter (8.33%), 2 patients with MRSE (multiresistant Staph. epidermidis), 13 patients with other multiresistant germs (36.11%) such as Streptococcus B, Enterococcus faecalis, Enterobacteriaceae, Klebsiella. Mobility class of amputees at the beginning of hospitalization: class 0 (= non walkers) all 36 patients (100%). Mobility class of amputees at the end of hospitalization: class 0 (= non walkers) are 5 patients (27.78%), class 1 (= only inside walkers) are 5 patients (13.89%), class 2 (= inside and little outside walkers) are 18 patients (50.00%), class 3 (= inside and good outside walkers) are 3 patients (8.33%). Amputation of the lower extremity following severe sepsis and septic shock is not rare – in our group we found more than 8%

External fixation is widely used in orthopaedic and trauma surgery. Infections around pin or wire sites, which are usually localised, non-invasive, and are easily managed, are common. Occasionally, more serious invasive complications such as necrotising fasciitis (NF) and toxic shock syndrome (TSS) may occur. . We retrospectively reviewed all patients who underwent external fixation between 1997 and 2012 in our limb lengthening and reconstruction programme. A total of eight patients (seven female and one male) with a mean age of 20 years (5 to 45) in which pin/wire track infections became limb- or life-threatening were identified. Of these, four were due to TSS and four to NF. Their management is described. A satisfactory outcome was obtained with early diagnosis and aggressive medical and surgical treatment. . Clinicians caring for patients who have external fixation and in whom infection has developed should be aware of the possibility of these more serious complications. Early diagnosis and aggressive treatment are required in order to obtain a satisfactory outcome. Cite this article: Bone Joint J 2015;97-B:1296–1300

Objective. This paper aims to analyze the kinetics of the over-ground wheel-type body weight supporting system (BWS); tendency changes of low extremity joint moment (hip, knee, ankle), 3 axis accelerations of a trunk, cadence and gait velocity as weight bearing level changes. Method. 15 subjects (11 males, 4 females, age:23.63.5, height:170.65.1cm, weight:69.0210.75kg) who had no history of surgery participated. 6 levels (0%, 10%, 20%, 30%, 40% and 50%) of BWS were given to subjects at self-selected gait velocity and kinetic data was calculated using a motion capture system, Vicon. ®. (Vicon, UK). Results. Maximum joint moments at the hip, knee, and ankle decrease as weight bearing increases on the sagittal plane. However, no significant decrease was found after 20% level of BWS at the hip and knee joint. On the other hand, the maximum ankle joint moment keeps decreasing. The root mean square (RMS) values of the acceleration in three directions: anterior-posterior (AP), medial-lateral (ML), and vertical(V) are analyzed. All 3-dimensional accelerations decrease as BWS increases while there is no significant difference over 20% level of BWS in the ML acceleration. V acceleration is reduced almost by half as soon as BWS level starts, but no further significant decrease can be found after 30% level of BWS. The AP acceleration tends to keep decreasing as BWS level increases. The cadence and gait velocity with wheel-type BWS decreases as BWS increases. Discussion. The maximum joint moments of the hip and knee do not significantly decrease when BWS exceeds a certain level, which is different from the case with BWS on treadmill; the maximum moments tend to keep decreasing linearly as BWS level increases on treadmill. In the case of the hip joint, the maximum moment is generated between toe-off and pre-swing phase, which generates force to push a trunk forward. With higher BWS, forward progression of the trunk is assisted by the wheel rather than driven by the lower extremity. It should be noticed that not only the tendency is different from BWS on treadmill, but the magnitude of the maximum hip moment is smaller than that of BWS on treadmill when BWS level is over 20%. The maximum knee joint moment is generated at the loading-response phase working as braking and shock absorption during gait, and thus the decrease in the maximum knee moment implies that less braking and shock absorption are required as BWS level increases. Only the maximum ankle joint torque keeps decreasing as BWS increases. The ankle moment is considered the largest contributor to forward acceleration. The tendency of the maximum ankle moment and the AP acceleration are similar (to what?) as weight bearing proceeds, which implies that walking speed slows down with the wheel-type BWS; the cadence is also reduced as BWS increases. Conclusion. The results highlight the difference of wheel-type BWS from BWS on treadmill, and provide information on how BWS level affects the joint moment and gait patterns. These outcomes can be utilized as a guideline of gait rehabilitation for people with lower-limb musculoskeletal impairments

Anterior cruciate ligament (ACL) rupture with associated meniscal pathology commonly occurs in a young, active population. Preserving a greater proportion of the meniscus may improve long-term outcomes by maintaining shock absorption and knee stability. However, meniscal repair procedures involve longer healing and rehabilitation than meniscal debridement, which could affect return to work and activity. The purpose of this study was to examine the functional outcomes and quality of life scores through two years in patients undergoing ACL reconstruction (ACL-R) who had meniscal repair, meniscal debridement, or no meniscal damage at the time of reconstruction. Data for 1814 skeletally mature patients with isolated primary ACL-R was prospectively collected at a single centre from January 2010 to December 2015. Functional testing of operative to non-operative limb performance was completed at one- and two-years following surgery and included single-leg balance, single-leg hop for distance, timed six-meter hop, triple-hop for distance, and triple cross-over hop for distance. ACL-Quality-of-life questionnaires (ACL-QoL) were completed pre-operatively and at 1- and 2-years post-operatively. Descriptive statistics were completed for patient demographics and intra-operative pathology. Unpaired t-tests using 95% confidence intervals were conducted to compare groups. The patient cohort was 45% female, with a mean age of 31 years (SD 11, range 14–66). Meniscal injury was detected in 1229/1814 knees (67.8%). There were 729 debridements and 538 repairs performed. Graft choice was hamstring autograft in 85.8% of cases, bone-patellar-tendon-bone autograft in 2.5%, allograft in 10.1% and other graft types in 1.5%. Pre-operative ACL-QoL scores were 29 and 28.5 for knees without and with meniscal damage, respectively (p>0.05). Of 1814 patients, 1269 (69.9%) completed the ACL-QoL at the two-year appointment, and 1225 (67.5%) completed the functional testing. At two years post-operative, patients with no meniscal damage at surgery demonstrated superior limb symmetry performance on triple-hop for distance compared to patients with meniscal damage (98.4% vs 97.1%, p < 0 .05, CI 0.1–2.5%). No other functional testing parameters showed statistical significance. There was no difference in functional outcome between patients undergoing an isolated meniscal repair versus debridement at one- or two-years. ACL-QoL scores were statistically significantly higher at one- and two-years post-operative for patients without meniscal damage (1-year: 73 vs 70.2, p < 0 .05, CI 0.51–5.1, 2-years: 79.2 vs 76.1, p < 0 .05, CI 0.79–5.4). ACL-QoL scores were minimally higher for isolated meniscal debridement compared to isolated meniscal repair at both time points (1-year: 71.4 vs 68, p < 0 .05, CI 0.4–6.4, 2-years: 78.3 vs 74, p < 0 .05, CI 1.3–7.3). Functional outcomes do not differ at one or two years post-operatively for patients undergoing meniscal repair versus debridement concomitant with ACL-R. Quality of life scores were statistically significantly higher for the patients with no meniscal pathology at both one- and two-years post-operative. ACL-QoL scores were also statistically significantly different for the meniscal repair and debridement groups however these differences are unlikely to be clinically significant. Extended follow-up is needed to determine if the differences detected in ACL-QoL scores are sustained over time, as well as the long-term role of meniscal injury on functional outcomes

Previous studies have indicated that prolonged surgical time may lead to higher rates of infection following total hip arthroplasty (THA). The purpose of this study was to evaluate the influence of surgical time on 30-day complications following THA and to determine if there was a time interval associated with worse outcomes. Patients ≥18 years who underwent THA between 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database using procedural codes. Patients with surgical durations >240 minutes were excluded. Patient demographics, operation length, and 30-day major and minor complications were ascertained. Multivariable regression was used to determine if the rate of complications differed depending on length of operation, while adjusting for relevant covariables, and to identify independent predictors of operation length. Covariables of interest included age, sex, American Society of Anaesthesiologists (ASA) class, smoking status, functional status, comorbidities, anesthesia type, and Body Mass Index (BMI). A total of 131,361 THA patients (average age 65 ±12 years) were identified from the database. Of these, 2,177 (1.64%) experienced a major complication, and 3,504 (2.64%) experienced a minor complication within 30-days of the initial procedure. Average operation length was 91.9 minutes (range 20 – 240 minutes). Independent predictors of prolonged operation length included overweight/obese BMI, male sex, cancer, dependent functional status, epidural anaesthetic, lower pre-operative hematocrit, and ASA class II, III or IV vs. I Alternatively, older age, current smoking, and spinal anaesthetic were associated with shorter surgical durations. Unadjusted rates of both major and minor complications were significantly higher for patients whose operation lengths were ≥ 120 minutes (P>0.001). Specifically, patients whose operations lasted ≥ 120 minutes had higher rates of septic shock, sepsis, pulmonary embolism (PE), deep vein thrombosis (DVT), urinary tract infection (UTI), renal insufficiency, surgical site infection(SSI) and wound disruption. After covariable adjustment, surgical durations of 90–119 minutes increased the risk of minor complications by 1.2 (95%Confidence interval [95%CI] 1.1–1.3), while surgical durations of 120–179 minutes increased the risk of major complications by 1.4 (95%CI 1.3 – 1.6), and minor complications by 1.4 (95%CI 1.2 – 1.5), and surgical durations ≥180 minutes increased the risk of major complications by 2.1 (95%CI 1.8 – 2.6), and minor complications by 1.9 (95%CI 1.6 – 2.3). There was no difference in the overall risk of complications for operation times lasting 20 – 39, 40 – 59, or 60 – 89 minutes (P>0.05). In terms of specific complications, operation length ≥90 minutes was determined to be an independent risk factor for deep and superficial incisional SSI, as well as wound disruption, while operation length ≥ 120 minutes was an independent risk factor for sepsis, UTI, and deep, non-incisional SSI and operation length ≥ 180 minutes was an independent risk factor for PE, DVT, and cardiac arrest (p < 0 .05). These data indicate that prolonged surgical durations may be an independent predictor of major and minor complications following THA. This suggests that quality improvements could be made to improve operating room efficiency and surgical times and therefore postoperative outcomes

DAIR procedure is well established for Prosthetic Joint Infection (PJI) in acute setting after total hip and knee replacements. We present our experience of DAIR following hip and knee replacements in a District General Hospital (DGH), where we delivered comparable results to leading tertiary centres in short to mid-term followup. We undertook a retrospective study involving 14 patients, who underwent DAIR in our DGH between August 2012 and December 2015. Patient cohort included primary, complex primary and revision hip and knee replacements. Microbiological support was provided by a Microbiologist with interest in musculoskeletal infections. 14 patients [9 males, 5 females; age 62 to 78 years (Mean 70.7); BMI 22 to 44.2 (Mean 33.8)] with multiple comorbidities underwent DAIR procedure within 3 weeks of onset of symptoms. 12 out of 14 grew positive cultures with two growing Vancomycin resistant Enterococci. Intravenous antibiotics were started after multiple samples intraoperatively and continued in six patients after discharge, while 8 were discharged with oral antibiotics. One patient died of overwhelming intraoperative septic shock in postoperative period. Another patient died of myocardial infarction subsequently. 12 (85.7%) patients were doing well with regular followup (Mean 20 months). With good patient selection, DAIR is a far simpler solution and a safe and reproducible surgical option for early PJI following hip and knee replacements compared to one or two stage revisions. But published data in contemporary literature is predominantly from specialised centres. Our small series provides a perspective of comparable early to mid-term results of DAIR from DGH

To evaluate efficacy and outcome of embolisation following pelvic ring injuries in patients presented with ongoing hypovolaemic shock. Between 2000 and 2003, 200 poly-trauma patients presented in our institutions following pelvic ring injuries. Those with ongoing hypovolaemic shock who were treated within 24h of admission with embolisation were included in this study. Demographics, mechanism of injury, ISS, type of pelvic ring fracture, arterial source of bleeding, hours from injury to embolisation, and outcome were all recorded prospectively. Out of the 200 treated in our institutions 17 (8.5%) underwent angio-embolisation. The mean age of the patients was 37 (14-70) and the mean ISS was 29. Distribution of pelvic ring injuries included: 3LC, 7APC, 7VS. The mean time from injury to embolisation was 15 hours. 8/17 patients were initially treated with an external fixator. The distribution of arterial injuries was: 7 superior gluteal arteries, 8 internal iliac arteries, 1 obturator artery and 1 internal pudental artery. The mean number of units transfused prior to embolisation was 22 (range 6-50). Mortality rate was 4 (23%) out of 17 embolised patients. Angio-embolisation for pelvic ring injuries occurred in 8.5% of our study population. This study indicates that only a small proportion of patients required embolisation secondary to arterial bleeding. The overall survival rate was in accordance to published international experience. Embolisation should be considered as a valid adjunct in some selected group of patients with pelvic fractures where ongoing bleeding refractory to other treatment modalities is present

The meniscus is at the cornerstone of knee joint function, imparting stability and ensuring shock absorption, load transmission, and stress distribution within the knee joint. However, it is very vulnerable to injury and age-related degeneration. Meniscal tears are reported as the most common pathology of the knee with a mean annual incidence of 66 per 100,000. Knee osteoarthritis progresses more rapidly in the absence of a functional meniscus. Historically, tears extending to the avascular inner portion of the meniscus (white-white zone, “WW”), such as radial tears were considered as untreatable and were often resected, due to the lack of vascularity in the WW zone. Perfusion-based anatomical studies performed on cadaveric menisci in the 1980s shaped the current dogma that human meniscus has poor regenerative capacity, partly due to limited blood supply that only reaches 10 to 25% of the meniscus, commonly referred to as red-red zone (“RR”). Previous studies, including those utilizing animal models have shown mobilization of Mesenchymal Stem Cells (MSCs) upon injury into the WW zone, and successful MSC recruitment when administered externally to the injury site. We and others have recently reported positive outcomes of repaired tears in the inner zone of patients. We hypothesized that the “avascular” white-white zone of the meniscus possesses regenerative capacity due to a resident stem/progenitor cell population. Further, we sought to redefine the presence of microvessels in all meniscal zones using advanced stereology and imaging modalities. Fifteen menisci from fresh human cadaveric knees (mean age: 21.53±6.53 years) without evidence of previous injury were obtained from two tissue banks (JRF, Centennial, CO) and Biosource Medical (Lakeland, FL) and utilized for this study. The use of cadaveric specimens for research purposes was approved by the institutional review board. Tibial plateaus were dissected to harvest medial and lateral menisci along their entire length. The RR, red-white (RW) and WW zones were dissected and separated into three thirds from the inner aspect to the marginal border of the meniscus and their wet weights recorded (Fig.1A). Meniscus tissue cellular content in each zone was obtained from dissociation of meniscus tissue using 0.02% w/v pronase (Millipore) for 1h at 37oC, followed by 18h 0.02% w/v collagenase II (Worthington) at 37oC with shaking. Isolated cells were characterized immediately after harvest using flow cytometry with antibodies against MSCs surface markers (CD105, CD90, CD44 and CD29) as well as respective isotype controls. Further, meniscal cells were cultured and split twice when confluence was reached, characterized at P2 and compared to bone marrow-derived MSCs (BM-MSCs) using the same markers. Self-renewal of cells was assessed using colony forming unit (CFU) assay. Differentiation assays were performed to assess whether colony-forming cells retained multilineage potential. For morphological examination of bigger vessels, samples were fixed in 10% formalin for 1 week, paraffin embedded, sectioned (4 μm thick) and stained with H&E and Masson's trichrome. Presence of microvessels was assessed by CD31 immunofluorescence staining. Further, menisci were cleared using the uDisco protocol labeled with the TO-PRO®-3 stain, a fluorescent dye that stains cell nuclei and imaged using light-sheet microscopy. All continuous data are presented as mean ±standard deviation. Non-repeated measures analysis of variance (ANOVA) and Tukey-Kramer HSD post hoc analysis were performed on sample means for continuous variables. Statistical significance was set at p < 0 .05. Menisci were successfully cleared using a modified uDISCO procedure, imaged and analyzed for total cell density. As expected, bigger vessels were observed in RR but not in WW. However, immunofluorescent staining for CD31 showed a subset of CD31+endothelial cells present in the WW zone, indicating the presence of small vessels, most likely capillaries. In order to assess whether enzymatic digestion had a differential result depending on meniscus zone due to cellular content, we analyzed yields per meniscus per zone. The wet weight of different zones (WW:RW:RR) was at a ratio of ∼1:3:5 respectively, however, the ratio of cells isolated from each zone was at ∼1:4:20, indicating that RR has a denser population of mononuclear cells. However, the difference between all zones in cell yields was not significant. The clonogenic potential of isolated cells was shown to be non-significantly different between the three zones. Differentiation of isolated cells to osteogenic lineage using osteogenic media in vitroshowed no difference between the three zones. Flow cytometry analysis of cells from the three meniscal zones displayed presence of two distinct subpopulations of cells immediately after isolation. One subpopulation was positive to MSC surface markers and the other negative. Additionally, flow cytometry of cultured meniscal cells at P2 displayed that the entire cell population was CD44+CD105+CD29+CD90+, suggesting that culturing meniscal cells results in selection of stem/progenitor cells (plastic adherence). Surface marker expression analysis showed differential expression patterns between markers depending on zone. Similar fraction of cells was detected to express both MSC markers CD90 and CD105 (7–10%) and similar fraction of cells expressed both MSC markers CD29 and CD44 (1–2%) in all three zones, indicating similar density of resident stem/progenitor cells in each zone. Importantly, WW showed significantly higher expression for all four MSC markers compared to the RR zone, indicating higher relative density of stem/progenitor resident cells in the WW zone. Our results determine that CD31-expressing microvessels were present in all zones, including the WW zone, which was previously considered completely avascular. Additionally, stem/progenitor cells were shown to be present in all three zones of the menisci, including the WW zone, showcasing its regenerative potential. For any figures or tables, please contact the authors directly

Purpose. Total knee replacement is the one of the most performed surgeries. However, patient's satisfaction rate is around 70–90 % only. The sacrifice of cruciate ligament might be the main reason, especially in young and active patients. ACL stabilizes the knee by countering the anterior displacing and pivoting force, absorbs the shock and provides proprioception of the knee. However, CR knees has been plagued by injury of PCL during the surgery and preservation of the ACL is a demanding technique. Stiffness is more common comparing to PS designed knee. To insert a tibial baseplate with PE is usually thicker than 8 mm comparing to 2–4 mm of removed tibial bone. The stuffing of joint space may put undue tension on preserved ACL and PCL. Modern designed BCR has been pushed onto market with more sophisticated design and instrumentation. However, early results showed high early loosening rate. Failure to bring the tibia forward during cementing may be the main cause. The bone island where ACL footprint locates is frequently weak, intraoperative fracture happens frequently. A new design was developed by controlled elevation and reattachment of the ACL footprint to meet all the challenges. Method. A new tibial baseplate with a keel was designed. The central part of the baseplate accommodates elevated bony island with ACL footprint. The fenestrations at the central part is designed for reattachment of bony island under proper tension with heavy sutures and fixed at anterior edge of the baseplate in suture bridge fashion and also for autograft to promote bony healing after reattachment. The suture bridge method has been used by arthroscopists for ACL avulsion fracture without the need of immobilization. The elevation of bony island release the tension in the ACL which come from stuffing of baseplate and PE insert and greatly facilitate cementing of the baseplate. The keel improve the weakness of traditional U shape design of BCR knees. Instead of keeping the bony island intact by separately cutting the medial and lateral tibial plateau in BCR knees in the past, we choose to saw the tibial plateau in one stroke as in PS knees, then removes the two condyles. The bony island includes the footprint both ACL and PCL. The central part of tibial baseplate will push the bony island upward which release the undue tension in the cruciate ligaments. Summary. We proposed a new solution for the kinematic conflict in the present bi-cruciate knee designs by elevation and re- attachment of bony island with ACL footprint at the same time simplify the ACL preservation. The simple tibial cutting procedure also facilitate the process. The technique protects PCL from injury during tibial bone cutting in CR knees. We believe the new BCR design has the potential to replace CR knee in term of function and longevity in the future

High-energy pelvic ring fractures are associated with polytrauma where staged surgery is recommended. While temporary skeletal stabilisation is part of the acute management, definitive care is done in a later phase. The purpose of this study was to evaluate the safety and efficacy of acute pelvic ORIF by comparing its short term outcome with those who were stabilised late. A 45-month retrospective review of the prospective pelvic fracture database of a level one trauma centre was performed. All high-energy trauma patients who were potential candidates for minimally invasive internal fixation of the pelvic ring were included. Patients were categorised as acute ORIF (<24 hrs) or late ORIF (>24 hrs). Demographics, ISS, pelvic AIS, 24 hour pack cell transfusions, physiological parameters, time to operating theatre, angiography requirement, LOS and mortality were recorded. Data was presented as mean+/−SD or percentages. Statistical significance was determined at ∗p<0.05 based on univariate analysis. Forty-three patients met inclusion criteria, seventeen patients had acute definitive ORIF (5.5 hrs to OT) and twenty-six late definitive ORIF (5 days to OT). Acute and late ORIF patients had statistically not different demographics (age: 48+/−22 years vs 40+/− 14, gender: 82% vs 79% males), injury severity (ISS: 30+/−18 vs 24.5+/−13, pelvic AIS: 3.7+/− 1 vs 3.4+/− 1.1) and 24 hour transfusion (4.7+/−5 U vs 6.6+/−4 U). Initial shock parameters were significantly worse in the acute ORIF group (∗SBP 69.7+/−17 vs 108+/−21 mmHg, ∗BD -7.35+/−4 vs -4.9+/−1.5 mEq/L, ∗Lactate 6.67+/−7 vs 2.51+/−1.3 mmol/L). Angiography was used 18% (3/17) vs 21% (6/29) of the cases. All early ORIF patients survived and one (3%) of the late ORIF patients died. The trend in shorter hospital LOS was not significant in the early ORIF group (25+/− 24 vs 37+/− 32 days) while the ICU LOS was comparable (12/17 patients with 2.9+/−2.5 days vs 15/26 patients with 3.7+/−3.6 days). Minimally invasive acute ORIF of unstable pelvic ring fractures could be performed even in severely shocked polytrauma patients. The procedure did not lead to increased rates of transfusion, mortality, ICU LOS or overall LOS. Furthermore, all these parameters showed a trend towards benefit compared to a staged approach

INTRODUCTION. Lumbar total disc replacement (TDR) is an alternative treatment to avoid fusion related adverse events, specifically adjacent segment disease. New generation of elastomeric non-articulating devices have been developed to more effectively replicate the shock absorption and flexural stiffness of native disc. This study reports 5 years clinical and radiographic outcomes, range of motion and position of the center of rotation after a viscoelastic TDR. Material and methods. This prospective observational cohort study included 61 consecutive patients with monosegmental TDR. We selected patients with intermediate functional activity according to Baecke score. Hybrid constructs had been excluded. Only cases with complete clinical and radiological follow-up at 3, 6, 12, 24 and 60 months were included. Mean age at the time of surgery was 42.8 +7.7 years-old (27–60) and mean BMI was 24.2 kg/m² +3.4 (18–33). TDR level was L5-S1 in 39 cases and L4-L5 in 22 cases. The clinical evaluation was based on Visual Analog Scale (VAS) for pain, Oswestry Disability Index (ODI) score, Short Form-36 (SF36) including physical component summary (PCS) and mental component summary (MCS) and General Health Questionnaire GHQ28. The radiological outcomes were range of motion and position of the center of rotation at the index and the adjacent levels and the adjacent disc height changes. Results. There was a significant improvement in VAS (3.3±2.5 versus 6.6±1.7, p<0.001), in ODI (20±17.9 versus 51.2±14.6, p<0.001), GHQ28 (52.6±15.5 versus 64.2±15.6, p<0.001), SF 36 PCS (58.8±4.8 versus 32.4±3.4, p<0.001) and SF 36 MCS(60.7±6 versus 42.3±3.4, p<0.001). Additional surgeries were performed in 5 cases. 3 additional procedures were initially planified in the surgical program: one adjacent L3-L5 ligamentoplasty above a L5S1 TDR and two L5S1 TDR cases had additional laminectomies. Fusion at the index level was secondary performed in 2 L4L5 TDR cases but the secondary posterior fusion did not bring improvement. In the 56 remaining patients none experienced facet joint pain. One patient with sacroiliac pain needed local injections. Radiological outcomes were studied on 56 cases (exclusion of 5 cases with additional surgeries). The mean location centers of the index level and adjacent discs were comparable to those previously published in asymptomatic patients. According to the definition of Ziegler, all of our cases remained grade 0 for disc height (within 25% of normal). Discussion. The silent block design of LP-ESP provides an interesting specificity. It could be the key factor that makes the difference regarding facets problems and instability reported with other implants experimentally or clinically. Unfortunately no other comparative TDR series are available yet in the literature. Conclusion. This series reports significant improvement in mid-term follow up after TDR which is consistent with previously published studies but with a lower rate of revision surgery and no adjacent level disease pathologies. The radiographic assessment of the patients demonstrated the quality of functional reconstruction of the lumbar spine after LP ESP viscoelastic disc replacement

Introduction. The viscoelastic cervical disk prosthesis CP-ESP is an innovative one-piece deformable but cohesive interbody spacer. It is an evolution of the LP-ESP lumbar disk implanted since 2006. The implant provides 6 full degrees of freedom including shock absorption. The design allows a limitation for rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion. It thus differs substantially from current prostheses. This study reports the clinical results of a prospective observational study series of 89 patients who are representative of the current use of the ESP implant since 2012. The radiological results are focused on the evolution of the mean center of rotation (MCR) as an additional information to the range of motion (ROM) for the evaluation of the quality of spine movement. Materials and Methods. 89 patients (33 males, mean age 45 years [28–60], 107 implants) were included for an open, prospective and non-randomized study between October 2012 and December 2015. One level patients were at C3C4 (3), C4C5 (3), C5C6 (41) C6C7 (24) C7T1 (1). Two levels patients were C4C5/C5C6 (3), C5C6/C6C7 (12), C6C7/C7D1 (1) and 3 levels C4C5/C5C6/C6C7 (1). Results. Clinical data were obtained preoperatively and at 3, 6, 12 and 24 months (mean ± SD): . Neck VAS:. 5,85±2,24. 2,34±1,95. 1,42±1,54. 2,25±1,75. 2,1±1,1. Arm VAS:. 6,5±1,95. 2,22±1,95. 1,5±2,0. 3±2,78. 1±2,5. NDI (%):. 55,8±15,2. 29,5±17. 18,9±15. 31±13. 21±11. SF 36 PCS (%):. 31±22,5. 50±14,9. 65±8,4. 44±12,8. 54±12. SF 36 MCS (%):. 32±13,9. 51±10,9. 69±8,5. 54±6,7. 59±8. We did not observe local ossifications. One case of side level degeneration was observed after 12 months in a C5C6 mono-segmental disk replacement (retrospectively this patient was a good case for a double initial implantation). To date the patient has not been re-operated. Two cases were revised (one C5C6 implant for bone ingrowth failure at 6 months and one C4C5 case for painful hypermobility in a globally stiff spine). Range of motion was obtained after 6 months and maintained at 24 months. Radiological study of the location of the mean center of rotation at the prosthesis level and adjacent disks demonstrated the adaptation ability of the implant. Conclusion. The concept of the ESP prosthesis is different from that of the “first generation” articulated devices currently used in the cervical spine. This study reports encouraging clinical results about pain, function and kinematic behavior. An interesting point is the evolution of the Mean Centers of Rotation in the. post-operative course. This adaptation ability is one of the main features as we need to consider the mean and long term evolution of the global cervical posture and mobility after a cervical disc replacement. Additional studies and longer patient follow-up are needed to assess long-term reliability of this innovative implant

Aims

This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures.

Introduction. Aseptic acetabular component failure rates have been reported to be similar or even slightly higher than femoral component failure. Obtaining proper initial stability by press fitting the cementless acetabular cup into an undersized cavity is crucial to allow for secondary osseous integration. However, finding the insertion endpoint that corresponds to an optimal initial stability is challenging. This in vitro study presents an alternative method that allows tracking the insertion progress of acetabular implants in a non-destructive, real-time manner. Materials and Methods. A simplified acetabular bone model was used for a series of insertion experiments. The bone model consisted of polyurethane solid foam blocks (Sawbones #1522-04 and #1522-05) into which a hemispherical cavity and cylindrical wall, representing the acetabular rim, were machined using a computer numerically controlled (CNC) milling machine (Haas Automation Inc., Oxnard, CA, USA). Fig. 1 depicts the bone model and setup used. A total of 10 insertions were carried out, 5 on a low density block, 5 on a high density block. The acetabular cups were press fitted into the bone models by succeeding hammer hits. The acceleration of the implant-insertor combination was measured using 2 shock accelerometers mounted on the insertor during the insertion process (PCB 350C03, PCB Depew, NY, USA). The force applied to the implant-insertor combination was also measured. 15 hammer hits were applied per insertion experiment. Two features were extracted from the acceleration time signal; total signal energy (E) and signal length (LS). Two features and one correlation measure were extracted from the acceleration frequency spectra; the relative signal power in the low frequency band (PL, from 500–2500Hz) and the signal power in the high frequency band (P Hf, from 4000–4800 Hz). The changes in the low frequency spectra (P Lf, from 500–2500 Hz) between two steps were tracked by calculating the Frequency Response Assurance Criterion (FRAC). Force features similar to the ones proposed by Mathieu et al., 2013 were obtained from the force time data. The convergence behavior of the features was tracked as insertion progressed. Results. Differences were noted visually between the acceleration data recorded at the beginning of insertion and towards the end, both in the time domain (fig. 2A) as well as in the frequency domain (fig. 2B). These differences were also captured by the proposed features. Fig. 3 shows a typical representation of how the time (A), frequency (B) and force (C) features evolved during insertion. Based on a simple convergence criterion, the insertion endpoint could be determined. Conclusions. The convergence behavior, and the insertion endpoint thus identified, of the force-based and acceleration based features correlated well. The different features capture the changes in damping and stiffness of the implant-bone system that are occurring as the insertion progresses and combining them improves the robustness of the endpoint detection method. For any figures or tables, please contact the authors directly

London's Air Ambulance (LAA) was first set-up in 1989 as a direct result of a Royal College of Surgeons of England Report highlighting poor trauma care provision. Since its inception, the service's mission is to be an innovative and effective provider of advanced pre-hospital care. The service provides a senior Doctor and senior Paramedic to the scene of any incident within the M25 by helicopter, during the day, and by fast-response car at night. The vast majority of doctors are usually Emergency Medicine Physicians or Anaesthetists. During a 6-month tenure, doctors will usually have completed a number of procedures, which include rapid sequence induction of anaesthesia, pre-hospital blood transfusion, and, procedural sedation. In terms of innovations, the organisation was the first in the UK to provide a 24/7 service. It was also the first to start pre-hospital Rapid Sequence Induction of Anaesthesia for the severely injured; Resuscitative Thoracotomy for the victims of penetrating trauma; and pre-hospital Blood Transfusion for shocked polytrauma patients. The service also has a very thorough induction programme, for new Doctors and Paramedics, and a highly structured Clinical Governance process. The post offers a unique and privileged opportunity to treat the most severely injured at the roadside

Military personnel operating on high speed marine craft are exposed to Whole-Body Vibration (WBV). Additionally planing craft operate at speeds with minimal contact of the hull with warer making the crew vulnerable to mechanical shock. An association between Low Back Pain (LBP) and exposure to WBV has been extensively reported in civilian literature. LBP is reported by military personnel operating on planing craft leading to downgrades and potential discharge. There is a clear need to understand the impact prolonged exposure has on our population operating these craft. We performed a bibliographical search of the PubMed database for records using a combination of keywords. Abstracts were screened for relevance and references cited in retrieved papers reviewed. There is no consensus in the literature on the potentially pivotal pathological process behind the association. Evidence from professional driving suggests current safe operating exposure levels require review to protect against long-term damage however with little evidence concerning the unique environment in which boats crews operate, the parity of these environments require investigation to allow direct comparison. Due to the prevalence of LBP in this population a need exists to establish the pathological process and add to the evidence base driving safe operating exposure levels