RESUMEN
BACKGROUND: The valgus-impacted (VI) 4-part fractures are a subset of fractures of the proximal humerus with a unique anatomic configuration characterized by a relatively lower incidence of avascular necrosis after operative intervention. OBJECTIVES: The present study reports the midterm clinical and radiological results of a large series of consecutive patients with 4-part VI fractures treated with a minimal invasive technique of internal fixation. METHODS: Over a ten-year period (2004-2014), we treated 56 patients with a true 4-part valgus impacted fracture of the proximal part of the humerus. Four patients were lost to follow-up and three died, leaving 49 patients (33 female, 16 males, average age 60,1 years) available for the study. Fracture fixation was achieved through the lateral transdeltoid approach with transosseous suturing of the tuberosities to each other, to the metaphysis and to the articular part of the humeral head avoiding gross disimpaction of the humeral head from the valgus position. Functional outcome assessment was performed using the parameters of the Constant-Murley score within a mean follow up period of 43,8 months (range, 24 to 115 months). RESULTS: All fractures were united within the first 3 months except one that showed late displacement and finally nonunion. The median Constant score was 81,7 points and the functional score in comparison with the unaffected shoulder was 86.2%. There were three patients with total Avascular Necrosis (AVN) of the head revised to hemiarthroplasty. The nonunion case was revised to reverse shoulder arthroplasty 12 months after surgery. In five cases, absorption of the greater tuberosity was noted in the last radiographic control without any serious consequences to the shoulder function. CONCLUSION: Advantages of this minimally invasive technique can be summarized as shorter operative time, no use of hardware, minimal soft tissue damage, low incidence of avascular necrosis, stable osteosynthesis with "tension band effect" and adequate rotator cuff repair allowing for early joint motion.