Proximal humeral fractures and intramedullary nailing: Experience with a new nail system

Abstract

Objectives: The goal of this study was to evaluate fracture healing and alignment as well as functional outcome and complication risks after internal fixation with the intramedullary proximal humeral nail (PHN). This device shows promise for applications involving the reconstruction of the humeral shaft and head with minimal soft tissue stripping and for providing a locked, fixed-angle construct for secure fixation to permit controlled, early, and active rehabilitation.

Design: Prospective case-series.

Setting: Multicenter study in 11 trauma units.

Patients: One-hundred and fifty-one patients were treated for the same number of proximal humerus fractures.

Intervention: Open reduction and internal fixation with the intramedullary PHN.

Main outcome measurements: Occurrence of postoperative complications during and up to 1 year of follow-up. The patients were actively followed up for 1 year with radiological assessment to observe fracture healing, alignment, reduction, and necrosis and by functional outcome measurements, including Constant, Disabilities of the Arm, Shoulder and Hand (DASH), and Neer scores.

Results: A total of 113 patients (77% of 147 surviving patients) were available for the 1-year follow-up assessment, among whom 99% of all examined fractures had healed at this last time point. The range of motion (ROM) of the injured shoulder satisfactorily improved between all of the follow-up periods and by 1 year, 84-92% (ratio of injured to healthy contralateral shoulder) capacity had been achieved for all movements. The Constant score had significantly increased at the 3- and 6-month follow-ups, and by the final 1-year examination, this score attained up to 89% of the contralateral side. The mean baseline DASH was 5.9, with 62% of the total patient population having a zero DASH score. DASH scores higher than the preinjury scores were only observed in patients > 90 years of age, with this score significantly increasing with a mean difference of five points at the 1-year follow-up. At this last examination time point, patients had also reached a "satisfactory" mean Neer score of 85. Intraoperative complications were few (i.e., only four cases were documented) and solely related to the surgical technique; these problems included perforation of the articular surface by the oblique bolt or incorrect positioning of an additional screw. Humeral head necrosis was not common, with only four cases observed. Implant/surgery complications occurred in 63% (30/48) of the patients and included 13 cases of "cut through" (secondary impaction of the humeral head), nine cases of perforation of the articular surface, and four cases of implant loosening. Only four deaths were reported, and all were considered to be purely related to the patient and not to their participation in this study.

Conclusion: Nailing of proximal humeral fractures with the PHN is possible, but indication is limited to mainly A- and B-type fractures. The results of this multicenter study with many participating surgeons show that the operative technique is demanding and that the majority of documented complications are related to a violation of published basic technical steps during the operative procedure.

Keywords: Intramedullary nailing of long bones; Shoulder and hand.