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

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 many¹¹ (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.

FIGURE 11-5 Viscoelastic tissue response to a constant force resulting in gradual stretching of the tissue. The potential for inflammation, however, is not demonstrated by this curve but is possible if the force is constantly present, which is the case in dynamic loading.

FIGURE 11-6 Commercially available dynamic splint. The tension and excursion may be adjusted by the patient.

FIGURE 11-7 The tissue response to the application of a single discrete force results in stress relaxation of the viscoelastic tissue.

FIGURE 11-8 During flexion and extension variable proportions of the applied load is converted to rotatory or compressive forces at the joints.

STATIC ADJUSTABLE SPLINTS

The classic static adjustable splint is a turnbuckle type and use was reintroduced several years ago by Green and associates.⁶ He reported an 80% success rate in treating elbow contractures from various etiologies, especially those with a major flexion contracture. Two problems were identified with the use of these splints.

As the contracture decreases to less than 30 degrees, the effectiveness of a turnbuckle to develop an extension torque decreases. Applying an extension load at this angle results in the majority of the force distributed so as to separate the hinge, and less than 25% of the force actually exerts an extension torque on the elbow (Fig. 11-9). The ability of this concept to enhance post-traumatic elbow motion has been recently demonstrated in a clinical trial.⁴ In another study, 11 of 22 patients gained satisfactory motion after initiating turnbuckle type bracing in a sample of those who no longer were benefiting from physical therapy.⁵

FIGURE 11-9 A, With the elbow at 90 degrees, the anteriorly placed turnbuckle provides an effective force, approximately 70% of which is directed at extending the elbow and 30% in separating the joint itself. B, When the elbow is at 30 degrees, the turnbuckle is working through an angle of 15 degrees. The sine function of 15 degrees is .25. This means that 75% of the force is going to separate the hinge and distract the two components of the brace, and only 25% of the force is actually extending the elbow. These types of braces become inefficient as the elbow gets closer toward full extension.

Hence, to develop a more effective device, a means was developed to apply the force through a gear mechanism at the axis of flexion; by so doing the entire force is then applied as intended: either to extend or to flex. (Fig. 11-10). The brace was designed at our institution and is termed the “Mayo Elbow Brace (Don Joy, Orthopedics) and is able to hyperextend to enhance the ability to completely resolve the contracture (Fig. 11-11). However, with flexion to more than 100 or 110 degrees, the anterior soft tissue tends to bunch up, limiting further flexion. For this reason, the straps closest to the joint may be released to allow unencumbered flexion.

FIGURE 11-10 A static adjustable splint currently used by the author in which the extension torque is directly applied at the axis of rotation. Note use of air pads to distribute the local pressure exerted on the skin.

FIGURE 11-11 The same splint shown in Figure 11-10, but reversed and being used in the flexion mode; hence, the splint is called the universal splint in our practice. For flexion the straps nearest to the hinge are released to avoid impingement.

Over the 4-year period from the introduction of this device in 2003 through 2006, we have prescribed approximately 200 braces for patients with various expressions of elbow stiffness. This experience has resulted in the application program shown in Box 11-1 and Figure 11-12. It should be noted that an adequate amount of time should be spent with the patient to explain the rationale of the brace and specific use and goals for the specific device being used.

FIGURE 11-12 A sample of the daily program given to the patient at the time of splint prescription.