OTA 2008 Posters

Scientific Poster #114 Upper Extremity OTA-2008

Medial Calcar Augmentation in Locked Plating of Proximal Humerus Fractures

Sreevathsa Boraiah, MD (n); Joseph U. Barker, MD (n); Robert J. Parker, BS (n);
Omesh Paul, MD (n); David L. Helfet, MD (n); Dean G. Lorich, MD (n);
Hospital for Special Surgery, New York, New York, USA

Purpose: The objective of this study was to evaluate the role of medial calcar support in maintaining fracture reduction after locked plating of proximal humerus fractures.

Methods: 57 patients who underwent locked plating of the proximal humerus were followed up until healing. The first 35 patients were placed into 2 groups (MS+, MS–) retrospectively, based on the medial support. Medial support was considered to be present if the medial cortex was anatomically reduced or the proximal fragment was reduced in slightly impacted valgus reduction. The final 22 patients (MA) in the series were treated prospectively with the understanding of importance of medial calcar support. Medial calcar augmentation was achieved by one of following methods depending the integrity of the medial cortex, and type of fracture:

1. placing an oblique screw positioned inferomedially in the proximal humeral head fragment;
2. placing an additional endosteal plate in the calcar region and locking the plate;
3. placing an additional prebent plate, which served as a fixed-angle device, with the bent portion running obliquely and inferomedially in the proximal humeral head fragment; or
4. placing a fibular allograft in the intramedullary cavity and locking the allograft with the lock screws from the proximal humerus locking plate.

For the initial and final radiographs, two lines were drawn perpendicular to the shaft of the plate, one at the top of the plate and one at the top of the humeral head, and the distance between them was measured as an indicator of maintenance of reduction.

Results: The augmentation of medial column had significant effect on the maintenance of fracture reduction (P <0.001). The average loss of reduction among the groups MS–, MS+, and MA was 5.8 mm, 1.2 mm, and 1.62 mm, respectively. There was no effect of age, sex, or fracture pattern on the maintenance of fracture reduction. In the MA group, there was no screw back-out and all patients healed without requiring a second operation.

Conclusions: Although locked plating achieves superior biomechanical results over the standard implants in osteoporotic bone, it does not prevent the osteoporotic head from sliding inferomedially over the implant. When medial column comminution exists, augmenting the medial calcar helps in retaining the reduction achieved during locked plating.

If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.