CHAPTER 11 Splints and Bracing at the Elbow

INTRODUCTION

Elbow splints are frequently employed at the elbow and function in several capacities: protection both static and dynamic, to deliver flexion or extension torque. Specifically, the four types of braces or splints used in the postoperative and postinjury management of the elbow include resting and hinged splints, and dynamic and static adjustable splints.¹⁰

STATIC AND PROTECTIVE SPLINTS

Prophylactic bracing is occasionally employed at the elbow, typically to avoid excessive extension in the athlete.⁹ Further static splinting for the elbow is commonly used for short periods as a protective measure after injury or surgery. Previously used commonly in those with rheumatoid arthritis, largely because of the effectiveness of disease remitting agents, this type of splinting is uncommonly indicated today (Fig. 11-1).

FIGURE 11-1 Resting splint rarely used for more than 2 to 3 weeks.

For the unstable elbow a hinged splint is used (Fig. 11-2). By initially locking the hinge, the same device can be used as a resting static splint; some designs allow conversion to a movable stabilizing device. Hinged splints allow active motion and are employed primarily for ligament healing. Occasionally, a hinged brace is prescribed for the resected elbow, but compliance is variable, and I rarely use this type of device.

FIGURE 11-2 Hinged splint allows static support when the mechanism is locked, and active motion thereafter as desired.

ELBOW STIFFNESS

The most common complication of elbow injury, and even in some arthritic conditions, is stiffness. The most important means of avoiding this after a fracture is rigid fixation accompanied by early motion of the joint (see Chapter 22). After fracture dislocation, it has been demonstrated that immobilization lasting for more than 4 weeks resulted in less satisfactory outcome in each patient,² and despite the recognized value of early motion after injury or surgery stiffness of the elbow remains a common problem in the orthopedic practice. Unfortunately, in the author’s experience the use of aggressive physical therapy to address post-traumatic stiffness is not always successful and, in fact, as often as not, makes the contracture worse. This justifies the use of splinting in this clinical setting, but to understand the rationale of splinting for this condition, it is necessary to understand the physiology of the process.

PATHOLOGY OF ELBOW CONTRACTURE

The exact reason that the elbow is so prone to joint contracture is not known with certainty. What is recognized is that the elbow is one of the most congruous joints in the body (see Chapter 2). Normally, the capsule is translucent, but with insult, it undergoes a marked hypertrophy and extensive cross-linking of the fibrils, as demonstrated on scanning electron microscopy (Fig. 11-3). In some instances, a severe elbow contracture has been observed after trivial insult or such as “strain” without fracture or dislocation. Under these circumstances, the elbow may contract rapidly, often within 2 to 3 weeks. An explanation of the rapid development of elbow contracture may be provided by the basic investigations on wound contracture. Experimental data demonstrate that dermal wounds undergo approximately 80% of the anticipated contracture within the first 3 weeks¹ (Fig. 11-4).

FIGURE 11-3 Scanning electron microscopy (×30) showing dense hypertrophy of collagen fibrils with extensive cross-linkage sites.

FIGURE 11-4 Experimental data showing that the majority of tissue contracture occurs in the first 3 weeks.

(With permission from Billingham, R. E., and Russell, P. S.: Studies on wound healing, with special reference to the phenomenon of contracture in experimental wounds in rabbits’ skin. Ann. Surg. 144:961, 1956, p. 964.)

Continuous motion, if properly used, has been shown to be an important adjunct to successfully alter this tendency and hence prevent contracture (see Chapter 10).

After trauma, this modality is used with confidence, particularly if rigid fixation has been afforded to the fracture and if pain and inflammation can be controlled. After 3 to 8 weeks of treatment and if the fracture has been rigidly fixed and it is thought that force can safely be applied, the use of splints may be introduced in order to gain further motion. In general, the author’s philosophy is that continuous motion machine maintains motion but does not gain motion. The use of static adjustable splints attains motion both in flexion and in extension. The question then arises as to the best method of providing a force to stretch the periarticular soft tissues. There are four possibilities: physical therapy, continuous passive motion, dynamic splinting, and static adjustable splinting.

MANAGEMENT OF ELBOW STIFFNESS

PHYSICAL THERAPY

Physical therapy must be executed with extreme caution in the post-traumatic or inflamed elbow. The reason for this is that passive stretch, in and of itself, can introduce the very inflammation that one is trying to treat in the course of the therapy. Inflammation results in contracture and thus is an obstacle to the treatment goal. A well-trained experienced physical therapist who understands this principle can be of value, especially to assist in addressing concurrent shoulder and wrist stiffness. Such expertise is not possible in the author’s practice; therefore, I have never prescribed physical therapy for a patient of mine with elbow stiffness.

RESTORATIVE SPLINTING

Restorative splinting can be used to assist in attaining elbow motion. Splints are designed according to two diverse philosophies: dynamic or static-adjustable. To comprehend the rationale of dynamic or static adjustable splinting, some understanding of the soft tissue about the elbow as viscoelastic tissue is necessary. If thesoft tissue at the elbow can be considered viscoelastic tissue, its response to a constant versus a variable force is different.¹² The theoretical response to a constant force is shown in Figure 11-5. This load results in soft tissue deformation, which is called creep.⁸ However, what is not demonstrated in this illustration is the development of inflammation as a biologic response to this constant load. Inflammation can alter this idealized curve, and in the author’s opinion, inflammation is a common byproduct of dynamic splinting. Nonetheless, this remains an attractive option for many ¹¹ (Fig. 11-6). The alternate approach to the stiff elbow is the use of static adjustable splints. In this modality, a constant force is applied to the elbow that results in strain being imparted to the tissue. However, the force is not continuously applied, allowing stress relaxation to occur within the soft tissue sleeve over a period of time. This type of treatment has been employed extensively at the knee by serial casting and has also been effectively used at the elbow.¹⁴ It is believed that the stress-free relaxation lessens the likelihood of inflammation, and thus, the elbow in our practice and opinion is more amenable to this type of load application (Fig. 11-7). The constant force is applied so as to exceed the elastic limits of the tissue or result in a stretch. But if this load is maintained at a constant and is not further increased, tissue relaxation should occur over time. Finally, to further avoid the likelihood of inflammation, the patient controls the amount and duration of tension being applied. This is done within a very discrete set of recommendations and a very defined program (see Appendix). However, as with all torque generated across the elbow by whatever means, a compressive force is also applied to the system. This joint force can reach considerable proportions and is a function of the direction of the torque and the ankle of the elbow at the time of application¹³ (Fig. 11-8). Ideally, the splint hinge mechanism absorbs the majority of the force which is primarily compressive in nature whether the application is in flexion or extension.