Compartment syndrome is a very serious musculoskeletal disorder, which can lead to devastating consequences, such as limb amputation and life-threatening conditions. It is a well described medical condition considered to be an orthopaedic emergency affecting all ages.

In the diagnosis of acute compartment syndrome, clinical suspicion supplemented by careful, repeated clinical examination continues to be the clinician's greatest tool. The classic signs and symptoms of acute compartment pressure are often listed as the 5 or 6 "Ps": Pain, Pressure, Pulselessness, Paralysis, Paresthesia, and Pallor. The diagnosis is typically not made by using equipment and it is difficult in the awake and oriented patient, becoming even more problematic in the polytrauma patient.

An alternative diagnostic method for compartment syndrome is invasive intra-compartmental pressure measurement via insertion of a pressure monitoring device into the muscle compartment. However, literature shows that commercially available intra compartmental pressure monitors have a highly variable intra-observer reproducibility and that user errors are common.

Compared to the invasive modalities or just experience of the surgeon, the CPMX1 shows promising advantages for the clinical application. Not only is the technology used for the CPMX1 device safe and non-invasive for the patient with only initial training required for the healthcare professionals, but it has also demonstrated high intra- and inter-observer reproducibility (as per bench tests and confirmed in clinical setting). Recently, two clinical studies ("SWISS_EVIDENCE" and "SWISS_CLEARANCE") were conducted using the CPMX1 in healthy volunteers in a real-world clinical environment. Results of these studies confirmed that the application of the CMPX1 in patient care is safe and validated the reliability of compressibility ratio measurement with the CPMX1 in healthy volunteers.

The use of the CPMX1 device therefore facilitates the measurements, as it is based on pre- existing ultrasound methods, and avoids any further risks to the patients compared to invasive compartmental pressure diagnosis methods.

Inclusion Criteria:

• Patients able to give consent
• Informed consent documented by signature
• Potential acute compartment syndrome (ACS) of the extremities (excl. hands, feet)
• Male or female
• Age 18 to 95 years
• Intact skin at the measurement site
• Open fracture up to Grade I if not in the measurement area

Exclusion Criteria:

• Potential Acute Compartment Syndrome (ACS) of both extremities considered
• Limb anomalies that could hinder the measurement
• Individuals who are deprived of liberty pursuant to an administrative order or court order or approval.