Risk factors for cephalic necrosis after plate and screw osteosynthesis of 3- and 4-part proximal humerus fractures: prospective cohort study of 121 patients.

PURPOSE

Avascular necrosis (AVN) of the humeral head is a relatively frequent complication after proximal humerus fractures (PHF), often leading to poor outcomes and reoperation. This study investigates both non-modifiable (fracture type, trauma energy, age, sex, Charlson comorbidity index) and modifiable (surgical access, bone graft use, reduction quality) risk factors for post-operative AVN in Neer 3-4-part PHFs.

METHODS

Patients with Neer 3-4-part PHFs treated using angular stable plates and followed for at least 6 months were included. Clinical and radiographic elements were evaluated. Statistical analysis was performed with SPSS 26, evaluating the data by both descriptive and univariate analyses.

RESULTS

Among 121 patients (mean age 63, mean follow-up 10.1 months), 8 developed AVN (6.6% incidence). Only 50% of AVN cases occurred within the first 15 months of follow-up. AVN was significantly associated with 4-part fractures (p = 0.050), medial hinge disruption (p = 0.022), tuberosity comminution (p = 0.003), failure to restore the cervico-diaphyseal angle (p = 0.022), and residual varus/valgus deformity (p = 0.01). The presence of a bone graft suggested a fourfold-increased risk of AVN (OR = 4.219).

CONCLUSIONS

The present study confirms that the risk of necrosis is predicted by the type of fracture, as well as by the quality of fixation. Age, sex and CCI of the patient, varus/valgus fracture displacement, glenohumeral dislocation and energy of the trauma did not suggest the risk of AVN. These findings underscore the importance of meticulous surgical techniques to address these factors and potentially reduce the incidence of AVN.

LEVEL OF EVIDENCE III

Prospective cohort study.