Upper Extremity Cast Application

Abstract

This chapter aims to provide a comprehensive review of the techniques and challenges associated with applying upper extremity casts in pediatric patients. The chapter, along with its accompanying figures and video clips, serves as an introductory guide to pediatric orthopaedic cast application for trainees. Generally, casts are used to preserve appropriate alignment rather than to create improved alignment. In cases of nondisplaced fractures or those with acceptable alignment, the role of the cast is to maintain that alignment until healing occurs. For fractures with unacceptable alignment, reducing them to an acceptable position is necessary while the cast is utilized to maintain proper alignment. For challenging fractures that are difficult to keep aligned, have displaced intraarticular components, or are length-unstable, surgical intervention is recommended, followed by casting for immobilization after surgery. This chapter reviews the indications, application, techniques, and pitfalls of short arm, thumb spica, mitten, ulnar gutter, long arm, and hanging arm casts.

Key concepts: (1)The cast index is a valuable measure that impacts the rates of loss of reduction in distal radius fractures.(2)Molds are important not only for maintaining fracture reduction but also for keeping the cast in position and preventing slippage.(3)Along with using a cast saw to split fiberglass casts, a cast splitter should be employed to ensure proper bivalving.

Keywords: Long arm cast; Mitten cast; Short arm cast; Thumb spica cast.

Figure 1

Supplies needed for short arm cast application.

Figure 2

Stockinette pieces should be fitted on the hand and forearm and then padded with cotton wrap.

Figure 3

Careful application of the fiberglass in the first webspace is essential to prevent cast irritation.

Figure 4

An example of a three-point mold.

Figure 5

A short arm cast after bivalving. Note that the bivalving is along the volar and dorsal surface as to not lose sagittal control of the reduction.

Figure 6

Placement and preparation of stockinette pieces for thumb spica cast.

Figure 7

Examples of thumb spica casts with interphalangeal (IP) joint free and IP joint immobilized.

Figure 8

Example of a thumb sprain without deformity (A) placed into a thumb spica cast in a hyperextended and hyperabducted position (B), now with an iatrogenically induced deformity (C) after cast removal.

Figure 9

Cast padding should extend 1 cm distal to the fingertips for a mitten cast.

Figure 10

“Fish mouthing” avoids crowding of the fingers.

Figure 11

Example of a covered mitten cast with fingers extended.

Figure 12

Stockinette placement for an ulnar gutter cast, which allows free motion of the index and long fingers.

Figure 13

Supplies needed for long arm casting.

Figure 14

An additional posterior slab of cotton padding is often needed.

Figure 15

A straight ulnar border is essential for application of a long arm cast. This prevents ulnar angulation of the forearm fracture after swelling goes down.

Figure 16

A supracondylar mold helps prevent cast slippage.

Figure 17

This 9-year-old girl has a 7-day-old proximal forearm fracture with 15° of angulation in her long arm flexion cast, who was indicated for reduction and placement of an extension cast.

Figure 18

The fracture is reduced under fluoroscopic imaging and the cotton is wrapped to include the thumb.

Figure 19

The fracture is reduced and held while the fiberglass hardens.

Figure 20

Supracondylar mold will prevent the cast from slipping distally.

Figure 21

The cast is finished and split to allow for swelling.

Figure 22

A D-ring may be fashioned to allow for easier sling use.