J Korean Orthop Assoc.  2014 Apr;49(2):140-146. 10.4055/jkoa.2014.49.2.140.

Conformity of Proximal Humerus Internal Locking Plate System (PHILOS) and Anatomic Features of Proximal Locking Screws: Cadaveric Study

• Jung GH
• Kim H
• Kim JD
• Cho HI

• KMID: 2185219
• DOI: http://doi.org/10.4055/jkoa.2014.49.2.140

Abstract

PURPOSE
The purpose of this cadaveric study was to evaluate the conformity of the anatomically preshaped proximal humerus internal locking plate system (PHILOS) to the humeri of the Korean and anatomical features of nine locking screws for the proximal humerus.
MATERIALS AND METHODS
This study included 20 adult humeri (average length 30.2 mm) with no deformity or previous surgery. PHILOS was applied to the lateral surface of the proximal humerus according to the contour. Then, the distance from the outer surface of the plate to the greater tuberosity and bicipital groove was measured. After K-wires were passed through the proximal locking guide, the intra-osseous length of K-wire and the configuration of the K-wire exit were evaluated.
RESULTS
The overall conformity of PHILOS was excellent at the lateral aspect of the proximal humerus. The tip of the plate had an average distance of 3.6 mm (range, 1.4-6.6 mm; standard deviation [SD], 1.27) from the greater tuberosity and 2.5 mm (range, 0.0-4.6 mm; SD, 1.24) at the bicipital groove and the average intra-osseous length of K-wire through the locking guide was 41.1 mm (range, 23.5-53.7 mm). K-wires were evenly penetrated through the humeral head. On H8 and H9, the bottom hole of PHILOS is closely located at the most inferior area of the humeral articular surface. The bicipital groove was pierced by K-wires of H5, which was the middle hole of PHILOS in four cases (20%).
CONCLUSION
PHILOS had excellent conformity with the proximal humerus and K-wires through the locking guide were evenly penetrated through the humeral head. However, much care should be taken in piercing of the bicipital groove in H5.

Keyword

proximal humerus; fracture; anatomical locking plate; PHILOS

MeSH Terms

Adult
Cadaver*
Congenital Abnormalities
Humans
Humeral Head
Humerus*

Figure

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  Figure 1 The Screw holes of proximal humerus internal locking plate system are numbered from superior to inferior and anterior to posterior.

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  Figure 2 K-wires through the locking compression plate drill sleeve are placed in the proximal humerus.

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  Figure 3 Distances from the greater tuberosity and bicipital groove to the plate are measured using the caliper.

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  Figure 4 Proximal humerus internal locking plate system is well fitted when applied to the humerus along the lateral surface of the proximal humerus.

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  Figure 5 K-wire though H5 pierced the bicipital groove.

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  Figure 6 The intra-osseous lengths of K-wire through the locking sleeve have clear characteristics. K-wires through H5, shortest, and K-wires through H7, longest. PHILOS, proximal humerus internal locking plate system.

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  Figure 7 Distribution of the K-wire exit hole.

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  Figure 8 The K-wire exit through H8 and H9 (black arrows) is close to the medial calcar of the proximal humerus.

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