Peripheral nerve injuries (PNI) occur in 10% of combat casualties. In the immediate field-hospital setting, an insensate limb can affect the surgeon's assessment of limb viability and in the long-term PNI remain a source of considerable morbidity. Therefore the aims of this study are to document the recovery of combat PNI, as well as report on the effect of current medical management in improving functional outcome. In this study, we present the largest series of combat related PNI in Coalition troops since World War II. From May 2007 – May 2010, 100 consecutive patients (261 nerve injuries) were prospectively reviewed in a specialist PNI clinic. The functional recovery of each PNI was determined using the MRC grading classification (good, fair and poor). In addition, the incidence of neuropathic pain, the results of nerve grafting procedures, the return of plantar sensation, and the patients' current military occupational grading was recorded. At mean follow up 26.7 months, 175(65%) of nerve injuries had a good recovery, 57(21%) had a fair recovery and 39(14%) had a poor functional recovery. Neuropathic pain was noted in 33 patients, with Causalgia present in 5 cases. In 27(83%) patients, pain was resolved by medication, neurolysis or nerve grafting. In 35 cases, nerve repair was attempted at median 6 days from injury. Of these 62%(22) gained a good or fair recovery with 37%(13) having a poor functional result. Forty-two patients (47 limbs) initially presented with an insensate foot. At final follow up (mean 25.4 months), 89%(42 limbs) had a return of protective plantar sensation. Overall, 9 patients were able to return to full military duty (P2), with 45 deemed unfit for military service (P0 or P8). This study demonstrates that the majority of combat PNI will show some functional recovery. Adherence to the principles of war surgery to ensure that the wound is clear of infection and associated vascular and skeletal injuries are promptly treated will provide the optimal environment for nerve recovery. Although neuropathic pain affects a significant proportion of casualties, pharmacological and surgical intervention can alleviate the majority of symptoms. Finally, the presence of an insensate limb at initial surgery, should not be used as a marker of limb viability. The key to recovery of the PNI patient lies in a multi-disciplinary approach. Essential to this is regular surgical review to assess progress and to initiate prompt surgical intervention when needed. This approach allows early determination of prognosis, which is of huge value to the rehabilitating patient psychologically, and to the whole rehabilitation team

It is unclear whether combat casualties with complex hindfeet fractures would have an improved outcome with reconstruction or amputation. This study aimed to determine the outcomes of British military casualties sustaining calcaneal fractures. In the 12 years of conflict in Iraq and Afghanistan there were 116 calcaneal fractures in 98 patients. Seventy-four patients (74/98 76%) were contactable, providing follow up data for 85 fractures (85/116 73%). Median follow up was 5-years (64 months, IQR 52–79). Thirty limbs (30/85 35%) had undergone trans-tibial amputation at time of follow-up: there was no association between open fractures and requirement for amputation (p=0.06). Definitive treatment choice had a significant association with later requirement for amputation (p=0.0479). Fifty-two patients (52/74 70%) had been discharged from the military due to their injuries: there was a significant association between amputation and military discharge (p=0.001). Only 17 patients (17/74 23%) had been able to complete a military fitness test since their injury. The median physical component score of the SF-12 quality of life outcome tool for those undergoing amputation was 51.9 (IQR 48.1–54.3). The median for those retaining their limb was 44.1 (IQR 38.6–53.8). The difference between the two cohorts was not statistically significant (p=0.989)

Introduction. We present the British Military's experience of treating devastating lower limb injuries in personnel returning from Iraq and Afghanistan. We evaluate current surgical practice of attempting to maximise stump length through sequential debridement, rather that early amputation outside the zone of injury. Following an observation that the frequency of sequential amputation had appeared to increase during spring 2009, it was speculated that there may be factors which would predict which patients would require a more aggressive early amputation. Methods. The Joint Theatre Trauma Registry was interrogated for all cases of amputation between April 2006 and September 2009. The following data were collected: demographics, mechanism of injury, requirement for massive transfusion, use of combat applied tourniquet, number of stump debridements and echelon of care performed, all microbiology and final level of amputation. A regression analysis was performed to establish correlation between each data-set and final level of amputation. Results. 95 cases were identified; 21 were either digits or upper limbs and excluded. Clinical notes of the remaining 74 cases were requested, of which 48 were available representing a total of 66 lower limb stumps. No significant relationships were established between sequential amputation and any of the variables we examined. It was not possible to identify factors with predictive value with respect to which patients would benefit from a more aggressive early amputation approach. Conclusions. These results support current practice by demonstrating that attempts to balance maximal stump length with sufficient debridement to eradicate infected tissue, does not expose patients to unnecessary operative ‘hits’

Aim

Treatment of prosthetic joint infection (PJI) by systemic administration of high doses of long-term antibiotics often proves ineffective, causing severe side effects. Thus, we presented the phage Sb-1, which coding extracellular polymeric substances (EPS) degradation depolymerases, conjugated with rifampicin-loaded liposomes (Lip-RIF@Phage) by bio-orthogonal functionalization strategy to target biofilm (Figure1).

This is a retrospective study examining the injury pattern, management and short-term outcomes of British Military casualties sustaining hindfoot fractures from the conflicts in Iraq and Afghanistan. In the 12-years of war, 114 patients sustained 134 hindfoot injuries. The calcaneus was fractured in 116 cases (87%): 54 (47%) were managed conservatively, with 30 (26%) undergoing internal fixation.

Eighteen-month follow-up was available for 92 patients (81%) and 114 hindfeet (85%). Nineteen patients (17%) required trans-tibial amputation in this time, with a further 17 (15%) requiring other revision surgery. Deep infection requiring surgical treatment occurred in 13 cases (11%) with S. aureus the commonest infective organism (46%). Deep infection was strongly associated with operative fracture management (p=0.0022). When controlling for multiple variables, the presence of deep infection was significantly associated with a requirement for amputation at 18 months (p=0.001). There was no association between open fractures and requirement for amputation at 18 months (p=0.926), nor was conservative management associated with amputation requirement (p=0.749).

The UK Military Trauma Registry was searched for all cases of primary bilateral lower limb amputation sustained over 6-years between March 2004 and March 2010. There were 1694 UK military patients injured or killed during this six-year study period.

Forty-three of these (2.8%) were casualties with bilateral lower limb amputations. All were men injured in Afghanistan by Improvised Explosive Devices. Six casualties were in vehicles when they were injured with the remaining 37 (80%) patrolling on foot. The mean New Injury Severity Score was 48.2 (SD 13.2). Nine patients also lost an upper limb (triple amputation); no patients survived loss of all four limbs. Six patients (14%) sustained an open pelvic fracture. Perineal/genital injury was a feature in 19 (44%) patients, ranging from unilateral orchidectomy to loss of genitalia and permanent requirement for colostomy and urostomy. The mean requirement for blood products was 66 units (SD=41.7). The minimum transfusion requirement was 8 units and the greatest was a patient requiring a total of 193 units of blood products.

Our findings detail the severe nature of these injuries together with the massive surgical and resuscitative efforts required to firstly keep patients alive and secondly reconstruct and prepare them for rehabilitation.

This study aimed to characterise severe open femoral fractures sustained by military personnel and to describe their orthopaedic management and preliminary outcomes. The UK Military Trauma Registry was searched for open femoral fractures sustained between 2006–2010. Clinical records and radiographs were reviewed and data gathered on demographics, injury, management and preliminary outcomes.

Thirty-four patients with 34 open femoral fractures were eligible for inclusion. The mean NISS was 22.4 (SD 12.28). Nineteen fractures were caused by gunshot wounds (56%), with the remainder due to blasts. Three patients (9%) suffered Grade 4 segmental bone loss. Intramedullary nailing was used in 22 patients (69%). A minimum of 12 month follow up was available for 33 patients (97%). Twenty-three patients (70%) had achieved fracture union within the first twelve months. One patient suffered deep infection requiring surgical debridement. Ten patients (30%) underwent a revision procedure due to femoral shortening or malunion: two required a transfemoral amputation. There was a significant association between bone loss and a poor outcome (revision surgery) at 12 months (p=0.00016). Infection rates were significantly lower in open femoral fractures when compared to similar published work on open tibial fractures (p=0.0257).

The TRISS methodology is used in by both the UK and US military trauma registries and relies on dividing casualties according to mechanism: penetrating or blunt. The UK and US military trauma registries use the original coefficients devised in 1987 and it is not clear how either registry analyses explosive casualties according to the TRISS methodology. This study aims to use the UK military trauma registry (JTTR) to calculate new TRISS coefficients for contemporary battlefield casualties injured by either gunshot or explosive mechanisms. The JTTR was searched for all UK Casualties injured or killed between 2003 and 2014. A logistic regression analysis was performed to devise new TRISS coefficients, these were then used to re-examine survival over the 12 years of the study. Comparing the predictions from the GSW TRISS model to the observed outcomes, it demonstrates a sensitivity of 98.1% and a specificity of 96.8% and an overall accuracy 97.8%. With respect to the explosive TRISS model, there is a sensitivity of 98.6%, a specificity of 97.4% and an overall accuracy of 98.4%. When this improved TRISS methodology was used to measure changes in survival, there was a sustained improvement over the 12-year study period.

Traumatic amputations (TAs) are amongst the most significant orthopaedic sequelae following IED strikes. Biomechanically, longer residual limb length confers better function. However, post-trauma definitive through knee amputation (TKA) remains controversial.

UK military casualties sustaining ≥1 major TA, 01/08/2008–01/08/2010 were identified using the UK JTTR and post mortem CT databases. All through- and below-knee TAs were termed ‘potential TKAs’ (p-TKAs); hypothetical candidates for definitive TKA. We hypothesised that traumatic TKAs were more common than previously reported (4.5% of lower limb TAs) and a significant cohort of blast injuries exist suitable for definitive TKA.

146 cases (75 survivors, 71 fatalities) sustained 271 TAs (235 lower limb). TKA rate was 34/235 (14.2%). 63/130 survivor TAs and 66/140 fatality TAs merited analysis as p-TKAs. Detailed pathoanatomy was only available for fatality p-TKAs, for whom definitive TKA would have been proximal to the zone of injury (ZOI) in only 3/66 cases.

Blast-mediated traumatic TKAs are significantly more common than previously reported (p=0.0118). Most lower limb TAs are skeletally amenable to definitive TKA. Maximising stump length for function incurs the risks of definitive amputation within the original ZOI (including infection and heterotopic ossification) but proximal extent of blast soft tissue injury commonly makes this unavoidable.

The incidence of PJI in knee replacements is 2.8% and slightly lower with hip replacement surgery. PJI make up 15% (or even more) of knee revisions. To combat PJI, antibiotic laden bone cement has been used for many decades, but antibiotic stewardship dictates more prudent management of antimicrobials. Projected increase in infection rate, due to increased surgery and latent infection to be almost 5-fold up to 2035. Biofilm is a complex structure of bacteria and polysaccharide matrix and, is recognised as a major component in PJI and other orthopaedic infections. Biofilm is responsible for high incidence of resistance to antimicrobials and ineffective host immune response. Method. Stabilized hypochlorous acid has been reported to have a rapid kill rate on all pathogens, including MDR pathogens associated with chronic and acute wound infections. It destroys biofilm on contact, is not cytotoxic, reduces inflammation and stimulates wound healing. 0,038% of Hypochlorous acid was used as prophylaxis against infection and to treat PJI. We report on our experience with hypochlorous acid as a wound irrigation as prophylaxis against infection (more than 600 cases) and for PJI. We also report on a University study where a head to head analysis was done on the anti-biofilm efficacy between hypochlorous acid 0,038% (Trifectiv Surgical Wound Irrigation) and Product X (an industry-standard product for the prevention and treatment of biofilm infection. Hypochlorous acid offers a valuable addition to the armamentarium of wound antiseptics, with added anti-inflammatory value. An in vitro study demonstrated superior efficacy against biofilm when compared to Product X

Scapular notching is a common problem following reverse shoulder arthroplasty (RSA). This is due to impingement between the humeral polyethylene cup and scapular neck in adduction and external rotation. Various glenoid component strategies have been described to combat scapular notching and enhance impingement-free range of motion (ROM). There is limited data available detailing optimal glenosphere position in RSA with an onlay configuration. The purpose of this study was to determine which glenosphere configurations would maximise impingement free ROM using an onlay RSA prosthesis. A three-dimensional (3D) computed tomography (CT) scan of a shoulder with Walch A1, Favard E0 glenoid morphology was segmented using validated software. An onlay RSA prosthesis was implanted and a computer model simulated external rotation and adduction motion of the virtual RSA prosthesis. Four glenosphere parameters were tested; diameter (36mm, 41mm), lateralization (0mm, 3mm, 6mm), inferior tilt (neutral, 5 degrees, 10 degrees), and inferior eccentric positioning (0.5mm, 1.5mm. 2.5mm, 3.5mm, 4.5mm). Eighty-four combinations were simulated. For each simulation, the humeral neck-shaft angle was 147 degrees and retroversion was 30 degrees. The largest increase in impingement-free range of motion resulted from increasing inferior eccentric positioning, gaining 15.0 degrees for external rotation and 18.8 degrees for adduction. Glenosphere lateralization increased external rotation motion by 13. 6 degrees and adduction by 4.3 degrees. Implanting larger diameter glenospheres increased external rotation and adduction by 9.4 and 10.1 degrees respectively. Glenosphere tilt had a negligible effect on impingement-free ROM. Maximizing inferior glenosphere eccentricity, lateralizing the glenosphere, and implanting larger glenosphere diameters improves impingement-free range of motion, in particular external rotation, of an onlay RSA prosthesis. Surgeons’ awareness of these trends can help optimize glenoid component position to maximise impingement-free ROM for RSA. Further studies are required to validate these findings in the context of scapulothoracic motion and soft tissue constraints

Introduction. Total knee and hip arthroplasty were the main arthroplasty surgery performed in Brazil. In Brazil, around 50% of arthroplasty surgeries are performed by the public health system, knowing as SUS . 1. SUS is the biggest public and universal health system in the world, attending 100% of the Brazilian population (220 million), with 2020's expected budget of US$ 31 billion . 2,3. . The National Institute of Clinical Excellence utilizes the QALY system (Quality adjustment year life)to calculate the best cost-benefit between medical interventions . 4. In compliance with the study, an operated person has a QALY index of £5000 while a non-operated person has an index of £7182. In March 2020, due to the COVID-19 pandemics, the Brazilian Health Ministry oriented for the postponing of elective surgery, to prioritize combating the virus . 5. This postponing, it was important but will cause an impact in the economy at the public health system from Brazil this year and in the next years. Therefore, this study aims to present the economic impact caused by COVID-19 pandemics in the public heal system, SUS, of Brazil. Methods. Data about total hip arthroplasty (THA) and total knee arthroplasty (TKA) in Brazil were collected from the TABNET portal of the Brazilian Health Ministry/Datasus . 6. It was collected information per month about hospitalization authorization (AIH), and total cost per AIH. The information regards the period of January to June from years 2015 to 2020. Results and Discussion. After the orientation in march 2020 to postpone elective surgery, there was a reduction of up to 91% in total knee arthroplasty (TKA) and 76% in total hip arthroplasty (THA), compared to the same period in the previous years (see Figure 1). This represents a reduction of more than 5000 surgeries in the first semester. According to Brazilian doctors, the retention of surgeries will result in excessive demand for the sector in the upcoming months . 7. . Due to the reduction of the AIH, which occurs a reduction US$3,881,494 of the budget destined for arthroplasty surgeries in the first semester of 2020 (see Figure 2), being used to the combat of COVID-19. Consequently, the purchase of new hip and knee prostheses decreases, harming the implant sales sector in Brazil. Furthermore, by the QALY system, the cost of a non-operated patient is up to 43% bigger than that of an operated patient. Thus, this will generate an increase in the expenses of the SUS in the upcoming months or years. Conclusion. The COVID-19 pandemics generate the need of postponing elective surgery of the SUS, such as total hip and knee arthroplasty. Because of this, there was a reduction of 67% of the number and expense of knee and hip arthroplasties in the first semester of 2020. This generates an economic loss for the implants companies and it will increase overly the demand for new surgeries in the upcoming months or years. For any figures or tables, please contact the authors directly

Aim. Infections represent a serious threat to the successful utilization of implants in modern medicine. Implant-associated infections are difficult to treat, because they involve biofilms that protect bacteria from the immune system and harbour antibiotic-tolerant persister cells. In this work, we developed an antibody-drug conjugate (ADC) containing the anti-neoplastic drug mitomycin C (MMC) as a novel treatment paradigm for implant-associated infections. MMC was chosen as it is a potent antimicrobial against biofilms and its synthesis into an ADC was chosen to alleviate toxicity. Following development and synthesis of the ADC, stability and release of MMC was measured. We then used the ADC to kill bacteria in suspension and in biofilms, in vitro and in vivo. Method. Mitomycin C was conjugated to a commercially available antibody against S. aureus via a disulfide linkage, with a drug release occurred via thiol-disulfide exchange. ADC as tested against S. aureus under various growth conditions (planktonic, persisters and biofilm). In vitro toxicity of ADC vs MMC was measured using a human cell line (MOLT-4). Finally, two independent in vivo experiments were performed in a murine implant-associated osteomyelitis model. In experiment one ADC treatment was compared NaCl, vancomycin and vancomycin + ADC (n=10 for all groups). Subsequently, ADC was compared to NaCl, the antibody used in the ADC construction, MMC and a novel ADC constructed with a non-S. aureus antibody (n=10 for all groups). All treatments were started day 7 post inoculation and were administered for 3 days. CFU enumeration was done following sonication to quantify bacterial load. Results. Drug release could be triggered on demand with N-acetyl cysteine and release occurred, once in contact with free thiols on S. aureus cell surface. The ADCs exhibited a concentration-dependent antimicrobial effect against S. aureus with doses exceeding 0.5 mg/l reducing amount of CFU to below detection limit (p< 0.001). 15 minutes exposure to ADC resulted in an approx. 2 log CFU/ml reduction compared to untreated biofilms (p < 0.01). In vivo ADC treatment was effective compared to NaCl treatment and the vancomycin treatment (p≤ 0.001). Further ADC and MMC treatment were comparable in efficacy, but both were superior than NaCl, pure antibody and the non-specific ADC (p≤ 0.05). Finally, in vitro cytotoxicity was significantly lower for ADC than MMC. Conclusions. In this study we have demonstrated that ADCs can be a novel treatment approach to combat implant-associated infections caused by S. aureus

Revision surgeries for orthopaedic infections are done in two stages – one surgery to implant an antibiotic spacer to clear the infection and another to install a permanent implant. A permanent porous implant, that can be loaded with antibiotics and allow for single-stage revision surgery, will benefit patients and save healthcare resources. Gyroid structures can be constructed with high porosity, without stress concentrations that can develop in other period porous structures [1] [2]. The purpose of this research is to compare the resulting bone and prosthesis stress distributions when porous versus solid stems are implanted into three proximal humeri with varying bone densities, using finite element models (FEM). Porous humeral stems were constructed in a gyroid structure at porosities of 60%, 70%, and 80% using computer-aided design (CAD) software. These CAD models were analyzed using FEM (Abaqus) to look at the stress distributions within the proximal humerus and the stem components with loads and boundary conditions representing the arm actively maintained at 120˚ of flexion. The stem was assumed to be made of titanium (Ti6Al4V). Three different bone densities were investigated, representing a healthy, an osteopenic, and an osteoporotic humerus, with an average bone shape created using a statistical shape and density model (SSDM) based on 75 cadaveric shoulders (57 males and 18 females, 73 12 years) [3]. The Young's moduli (E) of the cortical and trabecular bones were defined on an element-by-element basis, with a minimum allowable E of 15 MPa. The Von Mises stress distributions in the bone and the stems were compared between different stem scenarios for each bone density model. A preliminary analysis shows an increase in stress values at the proximal-lateral region of the humerus when using the porous stems compared to the solid stem, which becomes more prominent as bone density decreases. With the exception of a few mesh dependent singularities, all three porous stems show stress distributions below the fatigue strength of Ti-6Al-4V (410 MPa) for this loading scenario when employed in the osteopenic and osteoporotic humeri [4]. The 80% porosity stem had a single strut exceeding the fatigue strength when employed in the healthy bone. The results of this study indicate that the more compliant nature of the porous stem geometries may allow for better load transmission through the proximal humeral bone, better matching the stress distributions of the intact bone and possibly mitigating stress-shielding effects. Importantly, this study also indicates that these porous stems have adequate strength for long-term use, as none were predicted to have catastrophic failure under the physiologically-relevant loads. Although these results are limited to a single boney geometry, it is based on the average shape of 75 shoulders and different bone densities are considered. Future work could leverage the shape model for probabilistic models that could explore the effect of stem porosity across a broader population. The development of these models are instrumental in determining if these structures are a viable solution to combatting orthopaedic implant infections

Bone non-union following fracture is a major cause of morbidity in combat casualties. The various clinical treatments used to prevent or treat non-union remain of limited efficacy. Research therefore continues in pre-clinical animal models in an attempt to identify an effective clinical treatment. The aim of this study was to systematically evaluate emerging pre-clinical therapies in order to rationalise priorities for translational research. The methodological protocol of this study was registered with the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies (CAMARADES) and published. The review identified 3251 animal studies, 851 of which fulfilled the criteria for inclusion as detailed in the protocol. Of these, 702 of the studies described therapies that had progressed to clinical trials and were therefore excluded. The remaining 149 papers described eighteen categories of therapy that represent novel therapies yet to translate to clinical trials. These studies used a range of animal models, with heterogeneity that precluded formal synthesis and meta-analysis. This study provides a systematic evaluation of novel therapies with potential to prevent or treat non-union. It also represents a novel application of an emerging epidemiological technique to address a key priority in Combat Casualty Care research

Aims. The COVID-19 pandemic drastically affected elective orthopaedic services globally as routine orthopaedic activity was largely halted to combat this global threat. Our institution (University College London Hospital, UK) previously showed that during the first peak, a large proportion of patients were hesitant to be listed for their elective lower limb procedure. The aim of this study is to assess if there is a patient perception change towards having elective surgery now that we have passed the peak of the second wave of the pandemic. Methods. This is a prospective study of 100 patients who were on the waiting list of a single surgeon for an elective hip or knee procedure. Baseline characteristics including age, American Society of Anesthesiologists (ASA) grade, COVID-19 risk, procedure type, and admission type were recorded. The primary outcome was patient consent to continue with their scheduled surgical procedure. Subgroup analysis was also conducted to define if any specific patient factors influenced decision to continue with surgery. Results. Overall, 88 patients (88%) were happy to continue with their scheduled procedure at the earliest opportunity. Patients with an ASA grade I were most likely to agree to surgery, followed by patients with ASA grades II, then those with grade III (93.3%, 88.7%, and 78.6% willingness, respectively). Patients waitlisted for an injection were least likely to consent to surgery, with just 73.7% agreeing. In all, there was a large increase in the proportion of patient willingness to continue with surgery compared to our initial study during the first wave of the pandemic. Conclusion. As COVID-19 lockdown restrictions are lifted after the second peak of the pandemic, we are seeing greater willingness to continue with scheduled orthopaedic surgery, reinforcing a change in patient perception towards having elective surgery. However, we must continue with strict COVID-19 precautions in order to minimize viral transmission as we increase our elective orthopaedic services going forward. Cite this article: Bone Jt Open 2021;2(10):865–870

Orthopaedic reconstruction procedures to combat osteoarthritis, inflammatory arthritis, metabolic bone disease and other musculoskeletal disorders have increased dramatically, resulting in high demand on the advancement of bone implant technology. In the past, joint replacement operations were commonly performed primarily on elderly patients, in view of the prosthesis survivorship. With the advances in surgical techniques and prosthesis technology, younger patients are undergoing surgeries for both local tissue defects and joint replacements. This patient group is now more active and functionally more demanding after surgery. Today, implanted prostheses need to be more durable (load-bearing), they need to better match the patient's original biomechanics and be able to survive longer. Additive manufacturing (AM) provides new possibilities to further combat the problem of stress-shielding and promote better bone remodelling/ingrowth and thus long term fixation. This can be accomplished by matching the varying strain response (stiffness) of trabecular or subchondral bone locally at joints. The purpose of this research is therefore to determine whether a porous structure can be produced that can match the required behaviour and properties of trabecular bone regardless of skeletal location and can it be incorporated into a long-term implant. A stochastic structure visually similar to trabecular bone was designed and optimised for AM (Figure 1) and produced over a range of porosities in multiple materials, Stainless Steel 316, Titanium (Grade 23 – Ti6Al4V ELI) and Commercially Pure Titanium (Grade 2) using a Renishaw AM250 metal additive manufacturing system. Over 150 cylindrical specimens were produced per material and subjected to a compression test to determine the specimens' Elastic Modulus (Stiffness) and Compressive Yield Strength. Micro-CT scans and gravimetric analysis were also performed to determine and validate the specimens' porosity. Results were then graphed on a Strength vs. Stiffness Ashby plot (Figure 2) comparing the values to those of trabecular bone in the tibia and femur. It was found that AM can produce porous structures with an elastic modulus as low as 100 MPa up to 2.7 GPa (the highest stiffness investigated in this study). Titanium structures with a stiffness <500MPa had compressive strengths towards the bottom range of similar stiffness trabecular bone. Between 500 MPa − 1 GPa Titanium AM porous structures match the compressive strength of equivalent stiffness trabecular bone and from 1 GPa − 2 GPa the Ti structures exceed the strength of equivalent stiffness trabecular bone up to ∼2.5 times and consequently increase by a power law. These results show that AM can produce structures with similar stiffness to trabecular bone over a range of skeletal locations whilst matching or exceeding the compressive strength of bone. The results have not yet taken into account fatigue life with the fatigue life of these types of structures tending to be between 0.1 – 0.4 of their compressive strength. This means that a titanium porous structure would need to be 2.5 – 10 times stiffer or stronger than the portion of trabecular bone it is replacing. This data is highly encouraging for AM manufactured, bone stiffness matched implant technology

Heterotopic ossification is the formation of lamellar bone in soft tissues and is a common complication of high-energy combat injury. This disabling condition can cause pain, joint ankylosis, and skin ulceration in the residua of amputees. This project is aimed at developing a novel treatment to dissolve hydroxyapatite in heterotopic ossification and prevent the crystallisation of this this mineral at sites of ectopic bone formation. Previously reported results demonstrated that hexametaphosphate could dissolve hydroxyapatite at physiological pH. Further work has been undertaken to investigate the mechanism of this dissolution and establish a means of temporal control of action. In addition, physicochemical analyses of samples of human heterotopic ossification have yielded important insights into the nature of this pathological tissue. Techniques include mapped micro X-ray fluorescence, mapped Raman spectroscopy, scanning electron microscopy, and micro computed tomography. Formulation engineering work has begun in order to develop an appropriate delivery vehicle for this agent. This includes rheological testing and hexametaphosphate elution profiles. Finally, micro CT analysis has shown that hexametaphosphate is able to dissolve human heterotopic ossification tissue. In summary, this work has moved us closer towards our goal of a novel injectable agent for the treatment and prevention of heterotopic ossification

Post-surgical wound infections following total hip or knee arthroplasties can be a potentially catastrophic complication for the patient. Currently, several preventative measures exist to help combat this complication. One such method is skin disinfection with preadmission cutaneous chlorhexidine preparation. Although efficacious in reducing surgical site infections during total joint arthroplasty, orthopaedists should be aware of discrepancies between hip and knee arthroplasty. For example, Kapadia et al. performed a prospective study which evaluated the use of preadmission cutaneous chlorhexidine preparation on the reduction of surgical site infections following total hip arthroplasty; they found that there was a 3-fold higher relative risk of developing infection in patients who did not receive the chlorhexidine preparation as compared to those who did. In a similar study performed for total knee arthroplasty, the same authors founds a 6-fold higher relative risk of developing infection, which equated to double the risk as compared to total hip arthroplasty. In a study by Lewis et al. regarding timing to diagnosis of surgical site infections in post-hip and knee arthroplasties, the authors found a longer median time to diagnosis post-knee arthroplasty as compared to hip arthroplasty (25 vs. 42 days, p= <0.001). These finding suggest that orthopaedists should recognise that “A knee is not a hip” with regards to surgical site infections and should be aware of the discrepancies that exist between the two

Improve the quality of care mine-explosive wounds and preventing infection in mine blast injury. We have treated 19 patients affected by MEI during Anti-Terrorist Operation (ATO) in Ukraine. The patients had been received by our department within 5–28 days after the injury. All patients were comprehensively examined (general surgeon, neurosurgeon, thoracic surgeon, CT, X-ray, ultrasound, lab tests). 14/19 patients had an open fractures (10 of those 14 had a soft tissue defects). All patients with open fractures underwent secondary surgical treatment (radical debridement, irrigation, ultrasonic cavitation, fracture stabilization by external fixation). The patients with soft tissue defects underwent variety of plastic surgery. After soft tissues healing a plate or IM nail was installed. Evaluation of results was based on X-ray monitoring and the lower limb function assessment. 16 patients had full fracture consolidation and good function, 3 patients had slow consolidation and limitation of movement. Analysis of treatment showed that adherence to radical debridement and thorough soft tissue management led to significant reducing of the incidence of infectious complications in combat related fractures