RESUMO
BACKGROUND: Even though 20% of chronic lateral ankle instability results from a combined anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) injury, only the ATFL is sutured using arthroscopic ligament repair techniques. Although some biomechanical and clinical studies have proved that isolated ATFL repair yields excellent results, previous biomechanical studies were performed using systems that only allow indirect estimations. The purpose of this study was to clarify strain patterns by directly measuring repaired ATFL and CFL strain patterns on cadaveric models that underwent isolated ATFL repair of a combined ATFL and CFL injury. METHODS: The miniaturization ligament performance probe (MLPP) system was used for directly measuring the strain patterns to insert the strain gauges into the mid-substance of normal and repaired ATFL and CFL fibers in five cadaveric specimens to allow measurement of strain patterns in the axial and three-dimensional motion of the ankle. RESULTS: The normal and repaired ATFL showed similar strain patterns in axial and three-dimensional motions. During the axial range of motion of the ankle, the repaired CFL showed a strain pattern almost similar to that of normal CFL, but the strain increased as the plantar flexion or dorsiflexion angle increased to the maximum value of 100 at 30° plantarflexion or strain values of 17-55/100 at 15°dorsiflexion. During three-dimensional motion, the repaired CFL was under the maximum value of 100 during dorsiflexion-inversion and exhibited less strain (7-38/100) during plantar flexion-eversion. CONCLUSION: The repaired CFL did not show a strain pattern that was completely consistent with a normal strain pattern; however, it did have some degree of tension similar to a normal strain pattern, even though it was not directly repaired.
RESUMO
BACKGROUND: Patients with large bony defects of the ankle who wish to avoid amputation have limited surgical intervention options for limb salvage. Each of these interventions are technically complex and present significant risk for complications. The use of a patient-specific 3D-printed titanium cage in conjunction with a tibiotalocalcaneal (TTC) arthrodesis using a retrograde nail is another management option. This case adds to the scarce published literature on this technique. CASE PRESENTATION: This report presents the case of a 16-year-old female who suffered a traumatic partial amputation of her left distal lower extremity following an all-terrain-vehicle accident that resulted in a 10.0 × 10.0 cm skin laceration and a 5-cm subsegmental bony loss of the distal tibia. She was successfully treated using a patient-specific 3D-printed titanium truss cage in conjunction with a TTC arthrodesis using a retrograde nail. CONCLUSIONS: The decision to amputate or attempt limb salvage in a severely injured lower limb is still a topic of active debate. However, literature has shown that patients who undergo limb salvage surgery have better psychological health outcomes and equivalent functional outcomes as patients who have undergone amputation. Therefore, research on techniques that optimize and advance limb salvage surgery is needed. As the numerous potential benefits and limitations of patient-specific 3D-printed implants are assessed throughout the field of orthopedics, further research and cost-analysis will be required. Cases such as the one presented add to the limited existing literature of patient-specific 3D-printed implant for treatment of large distal lower extremity bony defects. LEVELS OF EVIDENCE: Level V (Case Report).