Complications encountered in proximal humerus fractures treated with locking plate fixation.

Objectives: We evaluated the complications encountered following locking plate fixation of proximal humerus fractures.

Methods: The study included 103 patients (70 females, 33 males; mean age 62 years; range 21 to 90 years) who were treated with open reduction and locking plate fixation for proximal humerus fractures between September 2005 and April 2009. Fixation was performed using the PHILOS locking plate in 93 patients, and S3 humerus plate in 10 patients. Postoperatively, a shoulder-arm sling was applied for six weeks and a standard rehabilitation program was used in all the patients. Intraoperative, acute postoperative, and late postoperative complications were assessed on radiographs. Varus inclination was defined as less than 120 degrees of the inclination angle on immediate postoperative radiographs, and varus displacement as postoperative increases in the varus angle. The mean follow-up period was 19 months (range 2 weeks to 43 months).

Results: Complications were seen in 10 patients (9.7%; mean age 67 years). The PHILOS plate was used in nine patients and S3 plate was used in one patient. Five patients (4.9%) had varus inclination with a mean inclination angle of 112.6 degrees (range 105 degrees to 118 degrees), four patients (3.9%) developed varus displacement with a mean inclination angle of 102.5 degrees (range 95 degrees to 110 degrees), and intra-articular screw penetration was seen in five patients (4.9%). The remaining complications were fixation failure (n=1, 1%), implant fracture (n=1), and deep infection (n=1). Screw penetration exceeded 3 mm in three patients, requiring revision surgery. The mean ages of patients with varus inclination, varus displacement, and screw penetration were 76.6, 74.4, and 71 years, respectively. Three patients with varus inclination (60%) developed varus displacement. Screw penetration was observed in three patients (60%) with varus inclination, and in all patients with varus displacement. The mean Constant-Murley shoulder score was 67.8 (range 50 to 90) in patients who developed a complication.

Conclusion: Our findings show that locking plate and screw systems represent a significant treatment option in the treatment of comminuted and displaced humerus fractures, with low complication rates. Accurate indication, protection of the head's inclination angle through appropriate surgical approach and proper technique, and fine calculation of screw length are essential for successful functional results.