A total absence of acute compartment syndrome (ACS) was noted in 966 tibial fractures in African patients of diverse ethnic groups, reviewed retrospectively at our institution. According to general incidences reported in the literature, we should have experienced between 22 and 86 cases of acute compartment syndrome. The purpose of this prospective study was to confirm these findings and at the same time to try to find an explanation for this phenomenon. During a period of 1 year and 4 months, 257 tibial fractures were prospectively analyzed for clinical signs and late sequelae of acute compartment syndrome. In 156 of these patients, presenting 158 fractures of the tibia, the pressure in the anterior compartment was systematically measured. Not a single case, nor late sequel of ACS was diagnosed. The hypothesis we forward for this total absence of ACS is the effect of chronic high temperature surroundings in preventing ACS by safeguarding the arteriovenous gradient and lowering the vascular resistance. We propose that further investigation should be carried out to study this hypothesis

This prospective clinical study investigates the relationship between intra-compartmental pressure and soft tissue oxygenation (StO2) measured non-invasively by near-infrared spectroscopy (NIRS) in patients at risk of acute compartment syndrome. Patients (over 13 years) with fractures of the tibial diaphysis or high-energy fractures of the forearm or distal radius, or patients with soft tissue injury were recruited. Non-invasive and invasive monitoring was carried out pre and post operatively. The ‘Delta P’ value (DP) was calculated as the compartment pressure subtracted from the diastolic blood pressure. The threshold for fasciotomy was a DP < 30mmHg. Non-invasive tissue saturation measurements and pressure measurements were taken from the same compartment (anterior tibial or volar forearm). StO2 values were simultaneously recorded from the contralateral (uninjured) limb at the same anatomical site. All patients had the difference between the StO2 value on the injured and uninjured sides calculated (‘StO2 difference’). 42 patients with tibial diaphyseal fractures, 2 patients with forearm fractures and one case with thigh swelling were recruited to the study. The mean age was 40 years (SD 17 years). 11 patients underwent a four-compartment lower leg fasciotomy determined by a DP < 30mmHg. Patients who required a fasciotomy had an ‘StO2 difference’ that was 20% lower (p = 0. 002) compared to those who did not develop acute compartment syndrome. This suggests that patients who require a fasciotomy have reduced StO2 values on their injured legs compared to the contralateral (uninjured) side. We have observed that non-invasive StO2 measurements for patients over 13 years at risk of acute compartment syndrome, correlates with the requirement for a fasciotomy as defined by P < 30mmHg. We are optimistic that near-infrared spectroscopy (NIRS) will be a reliable new non-invasive technique for detection of an acute compartment syndrome

Abstract. Background. Progressive muscle ischaemia results in reduced aerobic respiration and increased anaerobic respiration, as cells attempt to survive in a hypoxic environment. Acute compartment syndrome (ACS) is a progressive form of muscle ischaemia that is a surgical emergency resulting in the production of Lactic acid by cells through anaerobic respiration. Our previous research has shown that it is possible to measure H+ ions concentration (pH) as a measure of progressive muscle ischaemia (in vivo) and hypoxia (in vitro). Our aim was to correlate intramuscular pH readings and cell viability techniques with the intramuscular concentration of key metabolic biomarkers [adenosine triphosphate (ATP), Phosphocreatine (PCr), lactate and pyruvate], to assess overall cell health in a hypoxic tissue model. Methods. Nine euthanised Wistar rats were used in a non-circulatory model. A pH catheter was used to measure real-time pH levels from one of the exposed gluteus medius muscles, while muscle biopsies were taken from the contralateral gluteus medius at the start of the experiment and subsequently at every 0.1 of a pH unit decline. The metabolic biomarkers were extracted from the snap frozen muscle biopsies and analyzed with standard fluorimetric method. Another set of biopsies were stained with Hoechst 33342, Ethidium homodimer-1 and Calcein am and imaged with a Zeiss LSM880 confocal microscope. Results. Our study shows that the direct pH electrode readings decrease with time and took an average of 69 minutes to drop to a pH of 6.0. The concentrations of ATP, pyruvate and PCr declined over time, and the concentration of lactate increased over time. At pH 6.0, both ATP and PCr concentrations had decreased by 20% and pyruvate has decreased by 50%, whereas lactate had increased 6-fold. The majority of cells were still viable at a pH of 6.0, suggesting that skeletal muscle cells are remarkably robust to hypoxic insult, although this was a hypoxic model where reperfusion was not possible. Conclusions. Our research suggests that histologically, skeletal muscle cells are remarkably robust to hypoxic insult despite the reduction in the total adenine nucleotide pool, but this may not reflect the full extent of cell injury and quite possibly irreversible injury. The timely restoration of blood flow in theory should halt the hypoxic insult, but late reperfusion results in cellular dysfunction and cell death due to localised free radical formation. Further research investigating the effects of reperfusion in vivo are warranted, as this may identify an optimal time for using pharmacological agents to limit reperfusion injury, around the time of fasciotomy to treat acute compartment syndrome. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

The aim of this study was to document our experience of acute forearm compartment syndrome, and to determine the risk factors for requiring split skin grafting (SSG) and developing complications post fasciotomy. We identified from our trauma database all patients who underwent fasciotomy for an acute forearm compartment syndrome over a 22-year period. Diagnosis was made using clinical signs and/or compartment pressure monitoring. Demographic data, aetiology, management, wound closure, complications and subsequent surgeries were recorded. Outcome measures were the use of SSG and the development of complications following forearm fasciotomy. 90 patients were identified with a mean age of 33 yrs (range, 13–81 yrs) and a significant male predominance (n=82, p<0.001). A fracture of one or both of the forearm bones was seen in 62 (69%) patients, with soft tissue injuries causative in 28 (31%). The median time to fasciotomy was 12hrs (2–72). Delayed wound closure was achieved in 38 (42%) patients, with 52 (58%) undergoing SSG. Risk factors for requiring a SSG were younger age and a crush injury (both p<0.05). Complications occurred in 29 (32%) patients at mean follow-up of 11 (3–60) months. Risk factors for developing complications were a delay in fasciotomy of >6 hrs (p=0.018), with pre-operative motor symptoms approaching significance (p=0.068). Forearm compartment syndrome requiring fasciotomy predominantly affects males and can occur following either a fracture or soft tissue injury. Age is an important predictor of undergoing SSG for wound closure. Complications occur in a third of patients and are associated with an increasing delay in the time to fasciotomy

Purpose of the study: Acute compartment syndrome of the leg can lead to serious sequelae affecting patient autonomy. Retractile postischemic fibrosis leads to various deformities of the ankle and foot from simple claw toe to complex multidirectional dislocations. Aggressive surgery, or even amputation, may be needed to save soft tissue. Data are scarce on management practices for these deformities. We present a long-term follow-up. Material and method: From 1981 to 2006, 150 patients with a compartment syndrome of the leg were managed in our unit. Ten of these patients later required repeated surgery directly related to the sequelae of the compartment syndrome affecting the foot and ankle. These patients were followed in our unit. Personal data, as well as potential risk factors and sequelae were noted. Data were analysed and compared with reports in the literature. Results: For nine of the ten patients, the initial diagnosis was established late, for seven, more than 24 hours after onset. The anterior and lateral compartments were involved (10/10 and 9/10) and less often the deep posterior compartment (3/10), motor deficit (3/10) and sensorial deficit (5/10) of the tibial nerve. The deep posterior loge was the cause of late equine deformity in eight patients. Functional outcome was good in eight patients after secondary surgery. For the other two cases, leg amputation was the only solution. Discussion: Complicated acute compartment syndrome of the leg most commonly involves the anterior and anterolateral compartments. Conversely, the posterior compartment is implicated in the development of invalidating sequelae. We analysed the different procedures used in the literature for managing these sequelae and established a classification. Effective treatment of the foot and ankle affected by a late postischemic syndrome depends on a rigorous surgical strategy taking into account the multidirectional and multifactorial aspects of the resulting deformity. Prevention nevertheless remains the most effective treatment, both by early initial aponeurotomy and by prevention of the secondary deformity

Whilst emergency fasciotomy for acute compartment syndrome (ACS) of the leg is limb and potentially lifesaving, there remains a perception that such surgery may result in excessive morbidity, which may deter surgeons in providing expeditious care. There are limited long-term studies reporting on the morbidity associated with fasciotomy. A total of 559 patients with a tibial diaphyseal fracture were managed at our centre over a 7-year period (2009–2016). Of these patients, 41 (7.3%) underwent fasciotomies for the treatment of ACS. A matched cohort of 185 patients who did not develop ACS were used as controls. The primary short-term outcome measure was the development of any complication. The primary long-term outcome measure was the patient reported EQ-5D. There was no significant difference between fasciotomy and non-fasciotomy groups in the overall rate of infection (17% vs 9.2% respectively; p=0.138), deep infection (4.9% vs 3.8%; p=0.668) or non-union (4.9% vs 7.0%; p=1.000). There were 11 (26.8%) patients who required skin grafting of fasciotomy wounds. There were 206 patients (21 ACS) with long-term outcome data at a mean of 5 years (1–9). There was no significant difference between groups in terms of the EQ-5D (p=0.81), Oxford Knee Score (p=0.239) or the Manchester-Oxford Foot Questionnaire (p=0.629). Patient satisfaction on a linear analogue scale was reduced in patients who developed ACS (77 vs 88; p=0.039). These data suggest that when managed with urgent decompressive fasciotomies, ACS does not appear to have a significant impact on the long-term patient reported outcome, although overall patient satisfaction is reduced

Acute Compartment Syndrome (ACS) is an orthopaedic emergency that can develop after a wide array of etiologies. In this pilot study the MY01 device was used to assess its ease of use and its ability to continuously reflect the intracompartmental pressure (ICP) and transmit this data to a mobile device in real time. This preliminary data is from the lead site which is presently expanding data collection to five other sites as part of a multi-center study. Patients with long bone trauma of the lower or upper extremity posing a possibility of developing compartment syndrome were enrolled in the study. Informed consent was obtained from the patients. A Health Canada licensed continuous compartmental pressure monitor (MY01) was used to measure ICP. The device was inserted in the compartment that was deemed most likely to develop ACS and ICP was continuously measured for up to 18 hours. Fractures were classified according to the AO/OTA classification. Patient clinical signs and pain levels were recorded by healthcare staff during routine in-patient monitoring and were compared to the ICP from the device. Important treatment information was pulled from the patient's chart to help correlate all of the patient's data and symptoms. The study period was conducted from November 2020 through December 2021. Twenty-six patients were enrolled. There were 17 males, and nine females. The mean age was 38 years (range, 17–76). Seventeen patients received the device post-operatively and nine received it pre-operatively. Preliminary results show that post-operative ICPs tend to be significantly higher than pre-operative ICPs but tend to trend downwards very quickly. The trend in this measurement appears to be more significant than absolute numbers which is a real change from the previous literature. One patient pre-operatively illustrated a steep trend upwards with minimal clinical symptoms but required compartment release at the time of surgery that exhibited no muscle necrosis. The trend in this patient was very steep and, as predicted, predated the clinical findings of compartment syndrome. This trend allows an early warning signal of the absolute pressure, to come, in the compartment that is being assessed by the device. Preliminary results suggest that this device is reliable and relatively easy to use within our institutions. In addition it suggests that intracompartmental pressures can be higher immediately post-op but lower rapidly when the patient does not develop ACS. These results are in line with current literature of the difference between pre and post-operative baselines and thresholds of ICP, but are much more striking, as continuous measurements have not been part of the data set in most of past studies. Further elucidation of the pressure thresholds and profiles are currently being studied in the ongoing larger multicenter study and will add to our understanding of the critical values. This data, plus the added value of continuous trends in the pressure, upwards or downwards, will aid in preventing muscle necrosis during our management of these difficult long bone fractures

Failure to treat acute compartment syndrome (ACS) early leads to significant morbidity. Current practice depends on using clinical signs and intracompartmental pressure (ICP) monitoring to diagnose the syndrome but there is still debate regarding their accuracy and interpretation. Patients admitted with injuries at risk of ACS underwent intramuscular (IM) pH and ICP monitoring combined with regular clinical assessment. Fasciotomies were performed on those with clinical and/or pressure based evidence of ACS. All patients were subsequently assessed for evidence of a missed ACS at at 6 & 12 months. Of the 62 patients, 51 completed the protocol and were included in the analysis. They were divided into 2 groups: those who had ACS, either initially (fasciotomies; 13), or diagnosed at follow up (no fasciotomies; 7), and those with no evidence of ACS (31). The sensitivity and specificity for the worst values for each variable were calculated and receiver operator characteristic (ROC) curves generated. The area under the curve for pH was 0.92, 0.73 for absolute pressure and 0.59 for delta pressure. To achieve a sensitivity of 95%, an absolute pressure of >30mmHg was 30% specific, a delta pressure of <33mmHg was 27%, while IM pH of 6.38 was 80% specific. This study highlights the issues concerning current diagnostic methods for ACS. By comparison, IM pH radically out performed both the highest ICP and the lowest delta pressure, identifying patients early and accurately

The threshold for decompression in acute compartment syndrome is quoted as a pressure difference between the compartment and diastolic blood pressure of less than 30mmHg. This study reports the findings of continuous compartment pressure monitoring in children who underwent tibial osteotomies. In this prospective observational study, twenty seven children who underwent tibial osteotomies had anterior compartment pressures monitored using a transducer-tipped probe for a minimum of 72 hours following surgery. Pressure data were collected hourly together with evidence of clinical signs, symptoms and patterns of analgesic use. Patients were also reviewed for late sequelae of compartment syndrome. One case of compartment syndrome were encountered. Pressure differences (diastolic BP - compartment pressure) were found to vary widely, with many children exceeding the threshold for decompression but without manifesting other signs of compartment syndrome. Fasciotomies were not performed in view of the conflicting evidence and subsequent review confirmed the absence of late sequelae. In these children, low diastolic blood pressures were a common but normal feature. The prevalence of compartment syndrome was 3.7% (1/27). The positive predictive value of using the adult threshold was 7.1%; the negative predictive value was 100%. We conclude that the threshold for decompression as applied to adults is unsuitable for use in children inasmuch as a positive result would lead to a correct diagnosis in only 7.1% of children. A negative test is more useful in correctly excluding compartment syndrome in 100% of the children studied

Aims: To assess the effects of the various stages of intramedullary (IM) nailing of the tibia upon intracompartmental pressure (ICP) measurements, including new factors such as fracture impaction. Methods: Anterior compartment pressure monitoring was performed on 25 consenting patients undergoing IM nailing for tibial shaft fractures, using a sensitive transducer-tipped pressure monitor. Results: Signiþcant peaks in ICP, up to 130mmHg, occurred during reaming and nail insertion. Although the ICPs recorded post-operatively (32.79mmHg; range 10 to 68mmHg) were higher than the initial recordings (25.83mmHg; range 8 to 61mmHg), the change was not statistically signiþcant. Reduction of ICP was achieved through release of the traction, but the greatest drop in ICP followed impaction of the fracture after distal cross screw insertion (mean drop 21.75mmHg; range 5 to 58mmHg; p< 0.01). Conclusions: Using the various criteria for diagnosing acute compartment syndrome (ACS), some of our patients either had, or were at considerable risk of developing ACS postoperatively. Furthermore, if fracture impaction had not been performed where necessary, the subsequent sustained increase in ICP would have resulted in additional patients fulþlling the diagnostic criteria for ACS. Clearly, this observation may explain the tendency for some distracted fractures to fail to unite as a result of ischaemia, but of greater signiþcance is the potential for ACS to occur in the postoperative period, leading to signiþcant long term complications

Compartment syndrome (CS), a serious complication in paediatric trauma, can be prevented by timely diagnosis and adequate therapy.

From 1990 to 2000 we treated 22 patients with suspected CS in the arm. Incision into the intrafascial spaces of nine forearms and three hands confirmed the diagnosis. In 10 patients, fracture had caused the syndrome, and in two, the cause was contusion. In two patients the CS resulted from incorrect treatment procedures.

We also treated 22 patients with suspected CS in the lower limb. The diagnosis was confirmed in 15. Incision into the intrafascial spaces was performed during treatment, 13 times on the crus and twice on the femur. Fractures were always the primary cause.

In the upper limb outcomes were good. One patient developed a Volkman’s contracture but this was only disfiguring. Some patients treated for lower limb CS had cosmetic after-effects, but only one patient, in whom CS was diagnosed late, had functional after-effects.

We advocate permanent monitoring of intrafascial pressures, using piezoelectric sensors, and timely performance of adequate dermofasciotomies.

Purpose: Since the advent of pinning for supracondylar fractures of the humerus, Volkmann syndrome has been exceptional and most of the posttraumatic compartment syndromes observed in children have been seen in the lower limb. We propose an analysis of the causes, the diagnosis, the treatment and the results of treatment of acute posttraumatic compartment syndrome of the leg in children. Material and methods: Twenty-eight consecutive cases of acute posttraumatic compartment syndrome in 27 children were reviewed. These children were treated in two American paediatric traumatology units over a ten year period. We evaluated the cause of the trauma, associated lesions, clinical course, diagnostic methods, muscle compartment pressures, time from accident to diagnosis, and time from accident to surgery. Results were analysed at last follow-up. Results: The study population was 24 boys and three girls, aged 4 months to 15 years. Twenty-four children were pedestrian traffic accident victims. Twenty-two had a tibial fracture, four a femoral fracture, and two no fracture. Twenty-five compartment syndromes were diagnosed on the basis of compartment pressure measurements. Mean time from accident to diagnosis was 19 hours (range 2.5–85 hr). At diagnosis, exacerbated pain was observed in 26 children, paraesthesia in eleven, motor deficit in seven, and diminished pulses in three. Mean time from accident to surgery was 21 hours. Mean follow-up was 15 months. The final outcome was remarkably good. At last follow-up, 24 children were pain free, with no functional or sensorial deficit. Aponeurotomy had been performed very late (43, 83, and 86 hr) in the three patients who developed functional deficit. There were no cases of infection even when surgery was performed late. Discussion: Most children treated for acute posttraumatic compartment syndrome achieve a good result even when the time from accident to treatment is long, often more than 12 hours. All patients with sequellae at the last follow-up in our series had undergone aponeurotomy more than 36 hours after the accident. Conclusion: This is the first series devoted exclusively to acute posttraumatic compartment syndrome of the leg in children. The results were generally good despite significant time from accident to treatment

Background

Overlooked compartment syndrome represents a devastating complication for the patient. Invasive compartment pressure measurement continues to be the gold standard. However, repeated measurements in uncertain cases may be difficult to achieve. We developed a new, noninvasive method to assess tissue firmness by pressure related ultrasound.

Introduction: Acute compartment syndrome is most commonly seen in the lower limb. Only four cases have been reported in the paraspinal muscles. The common features of this condition have not been described. Methods: Following the successful surgical treatment of a case of bilateral paraspinal muscle compartment syndrome, a thorough search was made of all similar cases in Medline, and by hand-searching of references lists. Results: Only four other cases of non-traumatic paraspinal compartment syndrome were identified in the literature. Closer analysis revealed many features in common with our case. The condition tends to occur in skiers in their 20s with a previous history of exercise-induced back pain. Patients present with paraspinal muscle spasm and loss of sensation of the loin, after a few days of heavy exertion. There is abdominal tenderness and bowel sounds are reduced. Consistent findings on blood chemistry are marked elevation of creatinine kinase, myoglobin and LDH. There is an associated myoglobinuria. MRI is helpful in identifying extent of muscle involvement and guiding surgical intervention. The most useful investigation is the direct measurement of compartment pressures. Treatment can be operative or non-operative, although surgery is associated with more rapid recovery and elimination of pain. Discussion and Conclusion: The common features of acute paraspinal compartment syndrome of non-traumatic origin have not previously been recognised. We have helped define the characteristics of this condition to aid earlier recognition and treatment

Introduction and Aims: To assess the effects of the various stages of intra-medullary (IM) nailing of the tibia upon intra-compartmental pressure (ICP) measurements, with particular emphasis on factors which reduce the pressure.

Method: Using sensitive transducer-tipped pressure monitors, the anterior compartment pressure was recorded throughout IM nailing of tibial shaft fractures in 34 consenting patients.

Results: Significant peaks in ICP, up to 140mmHg, occurred during reaming and nail insertion, with a sustained elevated pressure phase seen following nail insertion (p< 0.01). In those patients with no fracture distraction visible on fluoroscopy following nail insertion, this pressure was relieved by the release of traction (mean reduction 16.79mmHg, p< 0.01). However, in those with a visible fracture gap, traction release was not sufficient, and impaction of the fracture after distal cross-screw insertion was required to achieve baseline levels in this group (mean reduction 15.29mmHg; p< 0.01).

Conclusions: Using the various pressure criteria for diagnosing ACS, some of our patients either had, or were at considerable risk of developing ACS post-operatively. Furthermore, if fracture impaction had not been performed where necessary, the subsequent sustained increase in ICP would have resulted in additional patients fulfilling the diagnostic criteria for ACS. Clearly, this observation may explain the tendency for some distracted fractures to fail to unite as a result of ischaemia, but of greater significance is the potential for ACS to occur in the post-operative period, leading to significant long-term complications. We recommend that, if traction is used, it is released as early as possible following nail insertion, and that the fracture should be impacted following distal cross-screw insertion if there is visible distraction of the bone ends on fluoroscopy following nail insertion.

The detection and treatment of acute compartment syndrome following trauma is critical if contractures, delayed fracture healing and possible amputations are to be avoided. The current standard for monitoring relies on invasive compartment pressure measurements. These require an additional procedure and cause discomfort to the patient. This prospective clinical study investigates the relationship between the intra-compartmental pressure and soft tissue oxygenation (%StO. 2. ) measured non-invasively by near-infrared spectroscopy (NIRS) in patients at risk of acute compartment syndrome. Adults with acute tibial or radial diaphyseal fractures were recruited on admission to the orthopaedic trauma unit. Non-invasive and invasive monitoring over anterior tibial or volar forearm compartments was carried out from admission and continued post-operatively. The differential pressure (ΔDP) was calculated as the compartment pressure subtracted from the diastolic blood pressure. The threshold for fasciotomy was a ΔDP < 30mmHg. StO. 2. values were simultaneously recorded from the contralateral (uninjured) limb at the same site. All patients had the difference between the StO. 2. value on the injured and uninjured sides calculated (‘StO. 2. difference’). Sixty patients with tibial fractures and 5 patients with forearm fractures were recruited. The mean age was 39 years (S.D.18 years). Fourteen patients underwent a four-compartment lower leg fasciotomy determined by a ΔDP < 30mmHg. We have observed that the difference in StO. 2. between limbs (measured non-invasively) was significantly lower in patients undergoing a fasciotomy. This suggests that NIRS is able to detect a change in oxygenation of the soft tissues in trauma patients developing an acute compartment syndrome. We are optimistic that near-infrared spectroscopy (NIRS) will be a reliable new non-invasive technique for detection of an acute compartment syndrome

In this work, we propose a new quantitative way of evaluating acute compartment syndrome (ACS) by dynamic mechanical assessment of soft tissue changes. First, we have developed an animal model of ACS to replicate the physiological changes during the condition. Secondly, we have developed a mechanical assessment tool for quantitative pre-clinical assessment of ACS. Our hand-held indentation device provides an accurate method for investigations into the local dynamic mechanical properties of soft tissue and for in-situ non-invasive assessment and monitoring of ACS. Our compartment syndrome model was developed on the cranial tibial and the peroneus tertius muscles of a pig's leg (postmortem). The compartment syndrome pressure values were obtained by injecting blood from the bone through the muscle. To enable ACS assessment by a hand-held indentation device we combined three main components: a load cell, a linear actuator and a 3-axis accelerometer. Dynamic tests were performed at a frequency of 0.5 Hz and by applying an amplitude of 0.5 mm. Another method used to observe the differences in the mechanical properties inside the leg was a 3D Digital Image Correlation (3D-DIC). Videos were taken from two different positions of the pig's leg at different pressure values: 0 mmHg, 15 mmHg and 40 mmHg. Two strains along the x axis (Exx) and y axis (Eyy) were measured. Between the two pressure cases (15 mmHg and 40 mmHg) a clear deformation of the model is visible. In fact, the bigger the pressure, the more visible the increase in strain is. In our animal model, local muscle pressures reached values higher than 40 mmHg, which correlate with observed human physiology in ACS. In our presentation we will share our dynamic indentation results on this model to demonstrate the sensitivity of our measurement techniques. Compartment syndrome is recognised as needing improved clinical management tools. Our approach provides both a model that reflects physiological behaviour of ACS, and a method for in-situ non-invasive assessment and monitoring

Abstract. Objectives. Acute compartment syndrome (ACS) is a progressive form of muscle ischaemia that is a surgical emergency and can have detrimental outcomes for patients if not treated optimally. The current problem is that there is no clear diagnostic threshold for ACS or guidance as to when fasciotomies should be performed. A new diagnostic method(s) is necessary to provide real-time information about the extent of muscle ischaemia in ACS. Given that lactic acid is produced by cells through anaerobic respiration, it may be possible to measure H+ ion concentration and to use this as a measure of ischaemia within muscle. Although we are familiar with the key biochemical metabolites involved in ischaemia; and the use of viability dyes in cell culture to distinguish between living or dead cells is well recognised; research has not been undertaken to correlate the biochemical and histological findings of ischaemia in skeletal muscle biopsies. Our primary aim was to investigate the potential for viability dyes to be used on live skeletal muscle biopsies (explants). Our secondary aim was to correlate the intramuscular pH readings with muscle biopsy viability. Methods. Nine euthanised Wistar rats were used. A pH catheter was inserted into one exposed gluteus medius muscles to record real-time pH levels and muscle biopsies were taken from the contralateral gluteus medius at the start of experiment and subsequently at every 0.1 of pH unit drop. Prior to muscle biopsy, the surface of the gluteus medius was painted with a layer of 50µmol/l Brilliant blue FCF solution to facilitate biopsy orientation. A 4mm punch biopsy tool was used to take biopsies. Each muscle biopsy was placed in a base mould filled with 4% ultra-low melting point agarose. The agarose embedded tissue block was sectioned to generate 400 micron thick tissue slices with a vibratome. The tissue slices were then placed in the staining solution with Hoechst 33342, Ethidium homodimer-1 and Calcein am. The tissue slices were imaged with Zeiss LSM880 confocal microscope's Z stack function. A dead muscle control was created by adding TritonX-100 to other tissue slices. For quantitative analyses, the images were analysed in Image J using the selection tool. This permitted individual cells to be identified and the mean grey value of each channel to be defined. Using the dead control, we were able to identify the threshold value for living cells using the Calcein AM channel. Results. Viability dyes, used primarily for cell cultures, can be used with skeletal muscle explants. Our study also showed that despite a significant reduction in tissue pH concentration over time, that almost 100% of muscle cells were still viable at pH 6.0, suggesting that skeletal muscle cells are robust to hypoxic insult in the absence of reperfusion. Conclusions. Viability dyes can be used on skeletal muscle biopsies. Further research investigating the likely associations between direct measured pH using a pH catheter, the concentrations of key cellular metabolic markers, and muscle tissue histology using vitality dyes in response to ischaemia, rather than hypoxia, is warranted. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

The clinical diagnosis of an acute compartment syndrome is most reliably based on increasing pain and pain on stretching the affected muscle groups. These signs cannot be elicited in the presence of epidural or regional blocks, or if the patient is unconscious. We present a national audit of consultant trauma and orthopaedic surgeons on the use of compartmental pressure monitoring in such patients. The postal questionnaire also asked whether a departmental protocol was in use and whether regional and epidural blocks were withheld in patients at risk of developing an acute compartment syndrome. 17% of consultants had such an agreed protocol, 53% did not have access to a continuous pressure monitoring device, 58% would request for an epidural/regional block to be withheld with only 2% routinely measuring compartment pressures in the presence of such a block. This study highlights a major deficiency in the clinical approach to a relatively common condition that may result in limb and life threatening complications and supports the recommendation for compartmental monitoring equipment to be made available

Introduction. The BOAST (British Orthopaedic Association Standards for Trauma) guidelines do advise that open pilon fractures amongst other open lower limb fractures need to be treated at a specialist centre with Orthoplastic care. The purpose of this study was to determine clinical outcomes in patients with open pilon fractures treated as per BOAST guidelines including relatively aggressive bone debridement. Methods. A retrospective analysis of a single surgeon series of open pilon fractures treated between 2014 and 2019 was conducted. Injuries were graded according to the Gustillo-Anderson classification and all patients were included for the assessment of the rate of infection and fracture healing. Functional outcome assessment was performed in all patients according to the American Orthopedic Foot and Ankle Score (AOFAS) at 6 months after definitive surgery. Initial wound with bone debridement and application of a spanning external fixator was performed within an average of 13.5 (Range: 3–24) hours. Fixation with FWF (Fine Wire Frame) was performed when the wound was healed, with the mean time from primary surgery to application of FWF being 24.5 (Range: 7–60) days. Results. There was a total of 20 patients including 16 males and 4 females. The mean age was 50.45 (Range: 16–88) years. Follow-up was for an average of 23.2 (Range: 5–51) months. There were 3 patients with Gustilo Type I injuries, 6 with Type II, 4 Type with type IIIa and 7 with Type IIIb injuries. Average time to bone union was 9.3 (Range: 2–18) months. The mean AOFAS score was 66 (Range: 15–97) points. TSF was used on 18 patients, while 2 patients had an Ilizarov frame. A corticotomy was performed on 4 patients with critical bone defect post debridement, while 2 patients had Stimulan beads with antibiotics. There was 1 case (5%) of deep infection and 9 cases (45%) of superficial infection. There were also 2 cases (10%) of non-union which required bone grafting from their femur using a RIA (Reamer Irrigation Aspirator). Other complications included 1 case of acute compartment syndrome, 1 case of pulmonary embolism, 1 case of necrotic skin and 1 case of amputation. Conclusion. Results of our study suggests that the use of staged wound debridement including relatively aggressive bone debridement in conjunction with antibiotics, external fixators and patient tailored conversion from spanning external fixator to fine wire frame achieves low rates of wound infection and complications for patients with open pilon fractures