Purpose: Hardly any other topic is as current as the gender-conscious medical treatment of every individual. Similarly, in sports, there are crucial differences that should be considered in order to treat everyone appropriately, with the aim to prevent injuries according to their needs. The objective of this study is to show that the differences between biological males and females are so significant that they require both specific injury prevention and therapy programs. Methods: This study is a retrospective analysis of letters from a department of orthopedics and trauma surgery between the years 2000 and 2015. Results: The analysis of 20,567 inpatient and outpatient letters of a level 1 trauma center in Germany revealed that 5455 patients suffered 7279 injuries; 1475 of the patients were female and suffered 2035 injuries, and 3890 patients were male and suffered 5244 injuries. Conclusion: The results show the differences between males and females with regard to sport-specific injuries, pointing out the sex differences in the sport-specific area in relation to the body region.

Aims: Biological augmentation is necessary in chronic sternoclavicular dislocations. However, the placement of drill holes for a graft can be difficult at that region. The aim of this study was to evaluate, as an early proof-of-concept, the feasibility of using a locally available clavicular periosteal flap (CPF) or sternal periosteal flap (SPF) for sternoclavicular joint (SCJ) stabilization and to biomechanically test the periosteal flaps. Methods: A cadaveric anatomic feasibility and biomechanical study (level of evidence V) was performed on nine SCJs. The CPF was mobilized from three sides by lifting the flap off the bone, preserving its attachment near the SCJ. Two 1.6 mm drill holes were created in the sternum, and the CPF was folded over the SCJ and fixed with a non-resorbable wire. Additionally, the non-resorbable wire was used in terms of a figure-of-8-bracing through a 1.6 mm clavicular drill hole to secure the joint position. Flap dimensions and sternal overlap were measured. Vice versa SPFs were prepared in selected specimens and fixed in a similar fashion. The CPFs were biomechanically tested using a uniaxial tensile testing machine to obtain values for stress at 50% strain (σ (50%)), maximum force (Fmax), maximum stress (σmax), strain at maximum force (ε(Fmax)), and strain at failure (ε at failure). Results: CPF mobilization and fixation were successfully achieved in all specimens. The flaps showed an average length and width of 3.5 × 2.6 cm and a sternal overlap of 2.0 cm. In four specimens, sternal periosteal flaps (SPF) were additionally mobilized, with an average length and width of 3.0 × 2.6 cm and a clavicular overlap of 2.1 cm. Both flap types demonstrated adequate size for sufficient joint overlapping. Biomechanical testing of the CPFs yielded a mean stress at 50% strain (σ (50%)) of 0.30 ± 0.12 N/mm ² , a maximum force (Fmax) of 18.55 ± 9.0 N, a maximum stress (σmax) of 0.48 ± 0.10 N/mm ² , a strain at maximum force (ε(Fmax)) of 1.69 ± 0.82%, and a strain at failure (ε at failure) of 2.36 ± 1.41%. Conclusion: This cadaveric study provides an early proof-of-concept demonstrating the feasibility of a novel SCJ stabilization technique using a locally available CPF or SPF. While this approach may offer advantages by minimizing donor-site morbidity associated with graft harvesting and potentially reducing surgical complexity, further biomechanical and clinical studies are required to establish its effectiveness and clinical applicability. Level of evidence: V.

Aims: The aim of this study was to test the feasibility of mobilizing an acromial periosteal flap (APF) and to evaluate its potential to provide locally available, additional biological autologous augmentation for acute and chronic acromioclavicular joint (ACJ) injuries. Methods: Ten cadaveric upper extremities (5 right, 5 left; 3 female, 7 male) with an average age of 82 ± 3.7 years were used. A direct surgical approach to the ACJ was performed, and the APF was mobilized from three sides of the acromion, leaving the side closest to the clavicle intact. The flap was folded over onto the clavicle and secured with a transosseous suture. Measurements of flap length, width, and clavicular overlap were recorded. Results: Mobilization of the APF was successfully achieved in all specimens. The flaps appeared clinically stable and tear-resistant, with an average length of 2.3 ± 0.5 cm, width of 1.75 ± 0.5 cm, and clavicular overlap of 1.29 ± 0.6 cm. Conclusion: Our study demonstrated the anatomical feasibility of preparing an acromial periosteal flap (APF). This anatomical proof of concept may provide the basis for potential future clinical applications as an additional option for biological augmentation in ACJ reconstruction. However, further biomechanical investigations and clinical studies are necessary to evaluate whether this technique can translate into improved stability and functional outcomes. Level of evidence: V.