The calcar screw in angular stable plate fixation of proximal humeral fractures - a case study

Georg Osterhoff,Guido A Wanner,Clément M Werner,Christian Ossendorf,Hans-Peter Simmen

doi:10.1186/1749-799x-6-50

Georg Osterhoff, Guido A Wanner + Show 3 more

Open Access

https://doi.org/10.1186/1749-799x-6-50

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Abstract

BackgroundWith new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw') has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications.MethodsPatients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-.ResultsFollow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M). Humeral head necrosis occurred in 6 (C+, 15.4%) and 3 (C-, 14.3%) cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7%) and 1 (C-, 4.8%) cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm) compared to C+ (0.77 ± 1.44 mm; p = 0.01).ConclusionsThe placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown.

Highlights

With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws (’calcar screw’) has increasingly been discussed
It could be noticed that fracture morphology differed between both groups and group C+ included considerably more complex fractures (Table 1)
In the present study it was shown that a loss of reduction over time could be prevented by the placement of one or two screws running tangentially to the medial curvature of the humeral surgical neck, commonly referred to calcar screws

Summary

Introduction

With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws (’calcar screw’) has increasingly been discussed. It has been suggested that the proximity to the anterior [30] and posterior [31] circumflex arteries might compromise perfusion of the humeral head and by this lead to delayed-union or non-union or to osteonecrosis. As they are supposed to stiffen the osteosynthetic construct, calcar screws may increase the risk of cut-out [32]

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