Assessment of a new technique for biological augmentation in sternoclavicular joint dislocations: a cadaveric feasibility and biomechanical evaluation.

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/mm2, a maximum force (Fmax) of 18.55 ± 9.0 N, a maximum stress (σmax) of 0.48 ± 0.10 N/mm2, 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.