In Vivo Ultrasound Shear Wave Elastography Assessment of Acute Compartment Syndrome in a Turkey Model.

OBJECTIVE: The aim of the work described here was to evaluate the objectivity and reproducibility of non-invasive intra-compartment pressure (ICP) measurement using ultrasound shear wave elastography (SWE) in a turkey model in vivo and to determine the biological and histologic changes in acute compartment syndrome (ACS). METHODS: Twenty-four turkeys were randomly divided into four groups based on the duration and fasciotomy of ACS created by infusion of up to 50 mm Hg in the tibialis muscle: group 1, ACS 2 h; group 2, ACS 4 h; group 3, ACS 2 h + fasciotomy 2 h; group 4, ACS 4 h + fasciotomy 2 h. For each turkey, the contralateral limb was considered the control. Time-synchronized measures of SWE and ICP from each leg were collected. Then turkeys were euthanized for histology and quantitative reverse transcription polymerase chain reaction (qRT-PCR) examination. RESULTS: All models created reproducible increases in ICP and SWE, which had a strong linear relationship (r = 0.802, p < 0.0001) during phase 1. SWE remained stable (50.86 ± 9.64 kPa) when ICP remained at 50.28 ± 2.17 mm Hg in phase 2. After fasciotomy, SWE declined stepwise and then normalized (r = 0.737, p < 0.0001). Histologically, the myofiber diameter of group 2 (82.31 ± 22.92 µm) and group 4 (90.90 ± 20.48 µm) decreased significantly (p < 0.01) compared with that of the control group (103.1 ± 20.39 µm); the interstitial space of all groups increased significantly (p < 0.01). Multifocal muscle damage revealed neutrophilic infiltration, degeneration, hemorrhage and necrosis, especially in group 4. Quantitative RT-PCR verified that interleukin-6 and heparin-binding EGF-like growth factor were significantly increased in group 4. CONCLUSION: SWE provided sensitive measurements correlating to ICP in a clinically relevant ACS animal model. Once ACS time was exceeded, progression to irreversible necrosis continued spontaneously, even after fasciotomy. SWE may help surgeons in the early detection, monitoring, prognosis and decision making on fasciotomy for ACS.

Tibial Plateau Fractures Complicated by Compartment Syndrome Are Associated With a 3 Times Higher Cost of Care.

OBJECTIVES: To determine the impact of acute compartment syndrome (ACS) and identify cost drivers of 1-year total treatment costs for operative tibial plateau fractures. DESIGN: Retrospective review. SETTING: Level 1 trauma center. PATIENTS: 337 patients with tibial plateau fractures, 24 of which were complicated by ACS. OUTCOMES: The primary outcome was total treatment cost over the first year for operatively treated tibial plateau fractures. The secondary objective was to use regression analysis to identify significant cost drivers. RESULTS: The diagnosis of ACS was associated with 2.85 times higher total treatment cost ( P < 0.001). ACS demonstrated increased total treatment cost when controlling for polytrauma ( P < 0.001) and postoperative infection ( P < 0.001). Regression analysis identified 5 variables significantly associated with total cost of care: body mass index, injury severity score, ACS, staged external fixation, and locking fixation ( P < 0.001; R 2 = 0.57). The diagnosis of ACS had the largest impact on total cost with a 3.5× greater impact on cost compared with the next highest variable, staged external fixation. CONCLUSIONS: Tibial plateau fractures complicated by ACS are associated with 2.85 times higher treatment costs over a 1-year period. There were 5 significant variables identified by regression analysis with ACS having the highest impact on total treatment. Together, these 5 factors account for 57% of treatment cost variability. LEVEL OF EVIDENCE: Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Point-of-care ultrasound assessment of a swollen limb following snakebite envenomation - an adjunct to avoid fasciotomy.

SUMMARY: Acute limb compartment syndrome can occur with cytotoxic snake envenomation. Ultrasound (US) assessment of the affected limb has been suggested as an adjunct to the administration of snakebite polyvalent antivenom to ameliorate the systemic and local effects. US may also aid in the diagnosis of compartment syndrome and the need for fasciotomy to prevent limb loss. This report presents an adult male who had severe soft tissue swelling from a puff adder bite to the wrist and highlights the use of US in assessing and monitoring the degree of swelling in subcutaneous and fascial compartments of the arm. This US monitoring in conjunction with frequent physical examination avoided the need for a fasciotomy and its attendant morbidity, resulting in complete resolution of the swelling and full recovery of limb function.

Early assessment of extremity compartment syndrome by biochemical markers in a rat model.

BACKGROUND: This experimental study aimed to define a biochemical marker that will enable early diagnosis of acute compartment syndrome (ACS) of extremities, a mortal condition that occurs due to trauma. METHODS: A total of 15 Wistar rats were included in the study in which saline infusion technique, a clinically compatible ACS model, was applied. After the rats were anesthetized with ketamine-xylazine, the in-compartment pressure of the hind limb was slowly increased with saline delivered through the angiocatheter, and after reaching the target compartment pressure, the pressure level was kept with a rubber tourniquet. The in-compartment pressure level was continuously monitored with a pressure transducer. The rats were divided into three groups. No intervention was applied to the control group (CG) (n = 3). In study group 1 (SG1) (n = 6), ACS was created using the saline infusion technique, keeping the in-compartment pressure between 30 and 40 mmHg for 45 min. In study group 2 (SG2) (n = 6), ACS was created using the saline infusion technique, keeping the in-compartment pressure between 30 and 40 mmHg for 90 min. Fasciotomy was performed on all rats. Tissue samples were obtained for histopathological examination and blood samples for biochemical analysis. RESULTS: Total oxidant status (TOS) (p = 0.004), ischemia-modified albumin (IMA) (p = 0.030), aspartate transferase (AST) (p = 0.003) and neopterin (p = 0.012) levels differed significantly between groups in the early period of muscle ischemia. In fact, TOS levels differed significantly between the groups even in the cellular phase where signs of ischemia were not observed (p = 0.048, p = 0.024). According to histopathological evaluation, there was no significant difference between the groups. DISCUSSION: TOS can be detected in the early reversible stage of ischemia, when the histopathological findings of ACS do not occur.

Epidemiology and management of proximal tibia fractures in children and adolescents: a population-based study based on the Kids' Fracture Tool.

BACKGROUND AND PURPOSE: Proximal tibial fractures are infrequent injuries in children, and the literature on epidemiology, associated injuries, and management is limited. We calculated a population-based incidence and described the characteristics of proximal tibial fractures in children in terms of complications and management. PATIENTS AND METHODS: This is a retrospective study over a 6-year-period during including 241 children with proximal tibial fractures who presented to our university hospital. Demographic and fracture-related data was collected from the Kids' Fracture Tool. The number of children during the study period was collected from statistical yearbooks of the City of Helsinki to estimate annual incidence. RESULTS: Extra-articular fractures (129/241) peaked at the age of 3 and tibial tubercle (42/241) and intra-articular fractures (70/241) peaked at the age of 15. Annual incidences were estimated to be 3.4/100,000 children and 22/100,000 children in the age group of 13-16 years for ACL avulsions, and 3.8/100,000 children and 21/100,000 children in the age group of 13-16 years for tibial tubercle fractures. The incidence of vascular compromise (0%) and compartment syndrome was low (0.4 %, 1/241). CONCLUSION: Proximal tibial fractures present with a bimodal distribution, with extra-articular fractures peaking at the age of 3 years and fractures of the tibial tuberosity and intra-articular fractures peaking at the age of 15 years. Additionally, associated compartment syndrome and vascular compromise was not as common as previously reported.

Assessment of complications associated with casting of acute distal radius fractures in adults.

PURPOSE: Controversy exists regarding the closed treatment of distal radius fractures. Circumferential casting of acute distal radius fractures has been shown to be safe in children, however, little research has demonstrated its safety in adults. The purpose of this study was to assess the risk of complications associated with casting acute distal radius fractures in adult patients. METHODS: Patients with a distal radius fracture treated by a single hand surgeon at a level 1 trauma center were retrospectively reviewed over a 3-year period. Patients were evaluated in the emergency room and were provisionally immobilized either with short-arm fiberglass casts or with splints. Patients were followed for a minimum of 4 weeks. Complication rates associated with casting were recorded, including rates of compartment syndrome and acute carpal tunnel syndrome. RESULTS: Eighty-one patients were included in this study. A total of 30 patients met inclusion criteria for placement of a short arm cast in the Emergency Department. Mean patient age was 63.2 years. The majority of patients sustained their injuries from a ground level fall. A minority of patients had radiographic evidence of intra-articular extension or underwent a reduction prior to casting. There were no patients who developed compartment syndrome or acute carpal tunnel syndrome as a result from the casting. The majority of patients did not require a cast change for at least 4 weeks. None of our patients went on to surgery. CONCLUSION: There were no major complications associated with casting of acute, low energy distal radius fractures in this series of 30 adult patients. While further studies with larger numbers of patients are necessary to establish safety of casting, this study suggests that casting may be a safe and effective treatment for low-energy distal radius fractures in adult patients presenting with a normal neurovascular exam. TYPE OF STUDY/LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Non-invasive and reliable assessment of compartment elasticity by pressure related ultrasound: An in-vitro study.

PURPOSE: The development of acute compartment syndrome is a serious threat to trauma patients. The clinical assessment alone is not reliable enough to determine the need for fasciotomy in many cases. The Physician´s assessment of the elasticity of the muscle compartment might be particularly important to objectively evaluate the pressure in this enclosed space. The purpose of this study was to determine the observer´s reproducibility, of compartment elasticity measurements by a novel ultrasonic approach. METHODS: Increasing intra-compartmental pressures (ICP) were simulated in a water filled in-vitro model. Pressure related ultrasound was used to determine the relative elasticity (RE) of soft tissue compartments. A pressure transducing probe head was combined with the ultrasonic probe to obtain cross section views of the simulated compartment and to detect the amount of applied pressure by the observer. In this model, the compartment depth without compression (P0) was set to be 100%. Changes of the compartment depth due to a probe pressure of 80 mmHg (P80) were correlated to P0 and an elasticity quotient as a value for RE (%) was calculated. Twelve blinded observers performed measurements for RE determination (%) under three pressure conditions. Reproducibility was calculated using intraclass correlation coefficient (ICC). RESULTS: Measurements (n = 432) revealed that the RE (%) in the control group was 17,06% (SD+/-2,13), whereas the RE of the group ICP30 significantly decreased to 12,66% (SD+/- 1,19) (p<0,001). The ICP50 group revealed a further significant decrease to 8,43% (SD+/- 0,67) (p<0,001). Repeated measurement of RE and ICP showed a high level of correlation (spearman correlation coefficient: roh=0,922). A RE <14% resulted in a sensitivity of 96% and a specificity of 90,3% for diagnosis of an ICP >30 mmHg. ICCinter was 0,986; 95%, CI: 0,977-0,992 (p<0,001). DISCUSSION: The presented ultrasound-based approach reliably assesses the elasticity in a simulated compartment model. In this pioneer study investigating the inter- and intra-observer reproducibility, this method of measurement appears to be of low cost in addition to being an easy and secure approach that may have the potential to substitute invasive measurement. Further investigations are required to improve its feasibility and to confirm the reliability under clinical conditions.

An Easily Assembled, Low-Cost Model for Lateral Canthotomy Education.

BACKGROUND: Lateral canthotomy is a vision-saving procedure. However, the low incidence of orbital compartment syndrome and the expense of simulators to practice this procedure can lead to low confidence and delays in the performance of the procedure by emergency physicians. DISCUSSION: We used a simple, inexpensive, easily assembled eye model for lateral canthotomy education at a residency program and a national conference obtaining feedback from simulation participants. Residents rated procedure laboratories that included the lateral canthotomy model as 4.9 to 5 (on a 5-point Likert scale, with 5 being the best score). National conference participants rated the model a 9 as a useful training model for practitioners on a 10-point Likert scale. CONCLUSION: This simple task trainer is practical, inexpensive, quickly assembled, and useful as a tool for practicing emergency medicine providers.

Portable Oxygen-Sensing Device for the Improved Assessment of Compartment Syndrome and other Hypoxia-Related Conditions.

Measurement of intramuscular oxygen could play a key role in the early diagnosis of acute compartment syndrome, a common condition occurring after severe trauma leading to ischemia and long-term consequences including rhabdomyolysis, limb loss, and death. However, to date, there is no existing oxygen sensor approved for such a purpose. To address the need to improve the assessment of compartment syndrome, a portable fiber-optic device for intramuscular oxygen measurements was developed. The device is based on phosphorescence quenching, where the tip of an optical fiber was coated with a poly(propyl methacrylate) (PPMA) matrix containing a brightly emitting Pt(II)-core porphyrin. The optoelectronic circuit is highly portable and is based on a microspectrometer and a microcontroller readout with a smartphone. Results from an in vivo tourniquet porcine model show that the sensor is sensitive across the physiological oxygen partial pressure range of 0-80 mmHg and exhibits an appropriate and reproducible response to changes in intramuscular oxygen. A commercial laboratory oxygen sensor based on a lifetime measurement did not respond as expected.

Malpractice Litigation for Compartment Syndrome.

BACKGROUND: The aim of this study was to analyze litigation involving compartment syndrome to identify the causes and outcomes of such malpractice suits. A better understanding of such litigation may provide insight into areas where clinicians may make improvements in the delivery of care. METHODS: Jury verdict reviews from the Westlaw database from January 1, 2010 to January 1, 2018 were reviewed. The search term "compartment syndrome" was used to identify cases and extract data on the specialty of the physician defendant, the demographics of the plaintiff, the allegation, and the verdict. RESULTS: A total of 124 individual cases involving the diagnosis of compartment syndrome were identified. Medical centers or the hospital was included as a defendant in 51.6% of cases. The most frequent physician defendants were orthopedic surgeons (45.96%) and emergency medicine physicians (20.16%), followed by cardiothoracic/vascular surgeons (16.93%). Failure to diagnose was the most frequently cited claim (71.8% of cases). Most plaintiffs were men, with a mean age of 36.7 years, suffering injuries for an average of 5 years before their verdict. Traumatic compartment syndrome of the lower extremity causing nerve damage was the most common complication attributed to failure to diagnose, leading to litigation. Forty cases (32.25%) were found for the plaintiff or settled, with an average award of $1,553,993.66. CONCLUSIONS: Our study offers a brief overview of the most common defendants, plaintiffs, and injuries involved in legal disputes involving compartment syndrome. Orthopedic surgeons were most commonly named; however, vascular surgeons may also be involved in these cases because of the large number of cases with associated arterial involvement. A significant percentage of cases were plaintiff verdicts or settled cases. Failure to diagnosis or delay in treatment was the most common causes of malpractice litigation. Compartment syndrome is a clinical diagnosis and requires a high level of suspicion for a timely diagnosis. Lack of objective criteria for diagnosis increases the chances of medical errors and makes it an area vulnerable to litigation.

Inpatient Versus Outpatient Treatment of Gartland Type II Supracondylar Humerus Fractures: A Cost and Safety Comparison.

BACKGROUND: In an effort to increase health care value, there has been a recent focus on the transition of traditionally inpatient procedures to an outpatient setting. We hypothesized that in the treatment of Gartland extension type II supracondylar humerus fractures (SCHF), outpatient surgery can be performed safely and with similar clinical and radiographic outcomes compared with urgent inpatient treatment with an overall reduction in cost. METHODS: We compared a prospective cohort of Gartland type II SCHF treated primarily as outpatients (postprotocol) to a retrospective cohort treated primarily as urgent inpatients (preprotocol), excluding patients with preoperative neurovascular injury, open fracture, additional ipsilateral upper extremity fracture, and prior ipsilateral SCHF. Inpatient versus outpatient treatment was also compared. Outcomes including perioperative factors, complications, readmission, reoperation, postoperative radiographic measurements, and direct hospital costs underwent univariate and multivariate analyses. RESULTS: A total of 220 patients in the postprotocol cohort (88 inpatients and 132 outpatients) and 129 in the preprotocol cohort (97 inpatients and 32 outpatients) were analyzed. There were no differences in operative times, number of pins, conversion to open reductions, readmissions, or reoperations between cohorts or groups, and no cases developed postoperative neurovascular injuries or compartment syndromes. Total complications did not differ between the preprotocol and postprotocol cohorts; however, were higher in the inpatient group (3.8% vs. 0%; P=0.016) in the univariate, but not multivariate analysis. There were no differences in Baumann angle or humerocondylar angle. Significantly more inpatients' anterior humeral line fell outside of the middle third of the capitellum in the univariate, but not multivariate analysis. There were significant reductions in total cost per patient between the preprotocol and postprotocol cohorts (marginal effect, -$215; P<0.0001) and between the inpatient and outpatient groups (marginal effect, -$444; P<0.0001). CONCLUSIONS: Delayed treatment of Gartland type II SCHF in the outpatient setting can be performed safely and with similar clinical and radiographic outcomes to those treated urgently as inpatients with a significant cost reduction. LEVEL OF EVIDENCE: Therapeutic level III-retrospective comparative study.

Fasciotomy Improvement Through Recognition of Errors Course: A Focused Needs Assessment for Error Management Training for Lower Extremity Fasciotomy Performance.

BACKGROUND: Many injuries from recent wars involve extremity trauma secondary to blasts, which predispose patients to developing extremity compartment syndrome. In military studies, 17% of fasciotomies required revision on arrival to a Role 4 hospital, and 41% of these had missed compartments, which is similar to that seen in civilian centers. While training has decreased this rate to 8%, this number is still too high. We conducted a focused needs assessment to guide the development of lower-extremity fasciotomy training. METHODS: In a predeployment assessment, 42 military surgeons performed a 2-incision, 4-compartment, lower-extremity fasciotomy on simulated lower leg models. Models were assessed for standardized and objectively-assessed major (inadequate skin or fascial incisions, missed compartments) and minor (failure to make an H-shaped incision over the lateral compartments, division of the greater saphenous vein) errors based on joint Trauma System clinical practice guidelines and approved training curricula. RESULTS: Four of 42 (9.5%) models contained no errors. Models averaged 4.3 ± 2.6 major and 0.3 ± 0.5 minor errors. 11 models (26.2%) had at least one missed compartment. The most common missed compartments were the deep posterior (17%) and anterior (14%). 29 (69%) had inadequate or poorly-placed skin incisions, with the most common being inadequate distal extension of the medial (10, 24%) and lateral (14, 33%) incisions, inadequate proximal extension of the lateral incision (6, 14%), medial incision too close to the tibia (7, 17%), and lateral incision over or behind the fibula (12, 29%). A total of 36 (86%) had inadequate fascial incisions. Inadequate fasciotomies were seen in the anterior (57%), lateral (55%), superficial (52%), and deep (34%) posterior compartments CONCLUSIONS: Performance on the models approximates what has been seen in military and civilian settings. This needs assessment will inform development of a simulation curriculum based on error-management and mastery learning theory to reduce the morbidity of lower-extremity compartment syndrome.

Exercise-induced leg pain in athletes: diagnostic, assessment, and management strategies.

The purpose of this review is to describe and critically evaluate current knowledge regarding diagnosis, assessment, and management of chronic overload leg injuries which are often non-specific and misleadingly referred to as 'shin splints'. We aimed to review clinical entities that come under the umbrella term 'Exercise-induced leg pain' (EILP) based on current literature and systematically searched the literature. Specifically, systematic reviews were included. Our analyses demonstrated that current knowledge on EILP is based on a low level of evidence. EILP has to be subdivided into those with pain from bone stress injuries, pain of osteo-fascial origin, pain of muscular origin, pain due to nerve compression and pain due to a temporary vascular compromise. The history is most important. Questions include the onset of symptoms, whether worse with activity, at rest or at night? What exacerbates it and what relieves it? Is the sleep disturbed? Investigations merely confirm the clinical diagnosis and/or differential diagnosis; they should not be solely relied upon. The mainstay of diagnosing bone stress injury is MRI scan. Treatment is based on unloading strategies. A standard for confirming chronic exertional compartment syndrome (CECS) is the dynamic intra-compartmental pressure study performed with specific exercises that provoke the symptoms. Surgery provides the best outcome. Medial tibial stress syndrome (MTSS) presents a challenge in both diagnosis and treatment especially where there is a substantial overlap of symptoms with deep posterior CECS. Conservative therapy should initially aim to correct functional, gait, and biomechanical overload factors. Surgery should be considered in recalcitrant cases. MRI and MR angiography are the primary investigative tools for functional popliteal artery entrapment syndrome and when confirmed, surgery provides the most satisfactory outcome. Nerve compression is induced by various factors, e.g., localized fascial entrapment, unstable proximal tibiofibular joint (intrinsic) or secondary by external compromise of the nerve, e.g., tight hosiery (extrinsic). Conservative is the treatment of choice. The localized fasciotomy is reserved for recalcitrant cases.

Assessment of normal forearm compartment pressures in a Nigerian population.

PURPOSE: The forearm is prone to raised compartment pressure and it is the second most common site for compartment syndrome. The normal compartment pressure of the forearm should be known and serve as a benchmark for the diagnosis of acute and chronic compartment syndrome. This study was aimed to determine the normal compartment pressures of the forearm using a digital compartment pressure monitor. METHODS: This was a prospective hospital-based study of the uninjured forearm in 30 patients, who presented with closed unilateral forearm fracture at the accident and emergency department of a tertiary health care facility, between June 2012 and December 2013. Approval was sought and obtained from institutions ethical committee. An 18 gauge bevelled-tip needle, attached to a Compass TM digital compartment pressure monitor made by Mirador USA, was used to measure the pressures in the compartments of the forearm. Data obtained were analysed using the Stata 12. Significance was determined at p < 0.05. RESULTS: The mean age was 38.3 ± 18.3 years with male-to-female ratio of 2.3:1. The pressures in the volar compartment of the forearm ranged from 1 to 8 mmHg with a mean ± SD compartment pressure of 4.7 ± 1.5 mmHg. In the dorsal compartment the pressure ranged from 2 to 8 mmHg with a mean ± SD of 4.9 ± 1.7 mmHg SD, while the lateral compartment measurement ranged between 1 and 5 mmHg with a mean ± SD of 3.6 ± 1.1 mmHg. There was significant positive correlation (p < 0.01) between the compartment pressures in the volar, dorsal, and lateral compartments. CONCLUSION: The normal compartment pressure for forearm is 4.4 ± 1.6 mmHg and ranged from 1 to 8 mmHg from this study in our environment. This will serve as reference value when forearm compartment pressure is being measured.

Assessment of Malpractice Claims Associated With Acute Compartment Syndrome.

BACKGROUND: Because acute compartment syndrome is one of the few limb-threatening and life-threatening orthopaedic conditions and is difficult to diagnose, it is a frequent source of litigation. Understanding the factors that lead to plaintiff verdicts and higher indemnity payments may improve patient care by identifying common pitfalls. METHODS: The VerdictSearch legal claims database was queried for the term "compartment syndrome." After 46 cases were excluded for missing information or irrelevancy, 139 cases were reviewed. The effects of plaintiff demographics, mechanism of injury, and complications were assessed. RESULTS: Of 139 cases, 37 (27%) were settled, 69 (50%) resulted in a defendant ruling, and 33 (24%) resulted in a plaintiff ruling. Juries were more likely to rule in favor of juvenile plaintiffs than adult patients (P = 0.002) and female plaintiffs than male plaintiffs (P = 0.008), but indemnity payments were not affected by the age or sex of the plaintiff. Plaintiffs who experienced acute compartment syndrome as a complication of surgery were more likely to win their suit and receive higher awards (P < 0.05), compared with those in whom the condition developed as a result of trauma. Amputation or delay in diagnosis or treatment did not affect plaintiff verdicts or awards. CONCLUSION: Defendants were more likely to lose a lawsuit concerning the management of acute compartment syndrome if the patient was a woman or child or if acute compartment syndrome developed as a complication of a surgical procedure.

Electrical burns in times of economic crisis: A new epidemiologic profile.

Electrical injuries and especially those of high voltage still remain a source of high morbidity. Over the past few years, a change in the epidemiologic profile of these lesions was noticed at the Vall d'Hebron University Hospital Burn Unit, corresponding to an increase in cases out of the legal framework. It is our aim to describe this particular subset, to determine the extent of their injuries and to understand the reason for their increased incidence. We think this was favoured by the rise in the unemployment rate, along with higher copper prices.

The "tight orbit": Incidence and management of the orbital compartment syndrome.

PURPOSE: The orbital compartment syndrome (OCS) constitutes a severe emergency, requiring immediate clinical diagnosis and surgical decompression. The key symptom is progressive visual impairment caused by an increase in intraorbital pressure, impairing the perfusion of relevant neurovascular and neurosensory structures. Intraorbital bleeding due to trauma and surgical intervention is known to be the main etiological factor. MATERIAL AND METHODS: A retrospective analysis of all patients affected by an OCS between January 1, 2012, and May 31, 2015, was performed. Patients' records were reviewed with regard to etiology, initial ophthalmologic status, fracture pattern, concomitant medication, surgical management, and postoperative outcome. The incidence of OCS was calculated based on the total number of craniomaxillofacial (CMF) emergencies. RESULTS: Within 3.5 years, a total of 18,093 CMF emergencies were registered. In 16 patients, an OCS was documented, corresponding to an incidence of 0.088%. The mean patient age was 67.31 ± 23.86 years, ranging from 22 to 102 years. The etiology varied, but trauma with subsequent intraorbital bleeding was the main cause. The use of anticoagulative medication was documented in 50% of the cases. In 14 patients, immediate surgical orbital decompression was performed: in 10 patients, vision could be preserved; in three patients, blindness resulted; and one patient was lost to follow-up. Two patients were managed without surgery. CONCLUSION: With regard to the total number of CMF emergencies, OCS is a rare condition. Early clinical diagnosis and surgical decompression are required to prevent permanent vision impairment. Anticoagulative medication must be considered as a predisposing factor for an orbital compartment syndrome in patients affected by periorbital trauma.

Assessment of elevated compartment pressures by pressure-related ultrasound: a cadaveric model.

PURPOSE: There is a risk of misinterpreting the clinical signs of acute compartment syndrome of the lower limb resulting in delayed fasciotomy. Up to date, the diagnosis of compartment syndrome is based on clinical assessment and of invasive needle pressure measurement in uncertain cases. Close monitoring is necessary for early recognition of raising compartment pressures. Clinical assessment of muscle firmness by the physician's palpation alone is unreliable. Thus, a device objectifying this assessment would be beneficial. The purpose of this study was to determine the feasibility of muscle compartment elasticity measurements by a novel and non-invasive device using pressure-related ultrasound. METHODS: In a cadaveric model, the anterior tibial compartment was prepared to simulate raising intra-compartmental pressures (0-80 mmHg) by saline infusion. Standard invasive pressure monitoring was compared with a novel method to determine tissue elasticity. Changing cross-sectional view in B-mode ultrasound was exerted to measure the compartment depth before and after physician's probe compression of 100 mmHg. Compartment displacement (∆d) was measured and related to the corresponding compartmental pressure (Spearman correlation coefficient). Delta (mm) of the control group at 10 mmHg compartment pressure was compared with measured data at rising compartmental pressures of 30, 50, and 70 mmHg using the Wilcoxon rank-sum test. The intra-observer reliability (κ) was additionally calculated. RESULTS: Fresh and never frozen lower human limbs (n = 6) were used. The average displacement measured in the anterior tibial compartment was 2.7 mm (0.3-6.7 mm). A concordant consistent correlation between the compartmental displacement and the intra-compartmental pressure occurred. The Spearman coefficient (r s = 0.979) showed a significant correlation between the rising pressure and the decreasing tissue displacement visualized by ultrasound. The intra-observer value kappa showed reliable values (κ 10 = 0.73, κ 30 = 0.80, and κ 70 = 0.79). CONCLUSIONS: We introduce a new method of ultrasound imaging enhanced with probe pressure measurement to determine changes of the visco-elastic behavior of isolated muscle compartments. Pressure-related ultrasound could be a reliable tool to determine the correlation between the measured compartmental displacement and the increasing intra-compartmental pressure. Its accuracy revealed promising results. This technique may help the physician to objectify the clinical assessment of compartment elasticity, mainly indicated in cases of unconscious patients and imminent pathology. Further clinical studies and improvements of this technique are required to prove its accuracy and reliability in cases of compartment syndrome.