Resurfacing Elbow Replacement Arthroplasty

CHAPTER PREVIEW

CHAPTER SYNOPSIS:

Resurfacing arthroplasty of the elbow is not new, but it is just now becoming a viable treatment option for specific indications. Off-label use of commercially available implants allows for resurfacing of portions of the distal humerus, part of or the entire capitellum, the entire distal humerus, and the proximal radial head. The experience with these implants is limited but growing. Early results are promising, and the goal of maximizing bone stock, while addressing arthritis of the elbow, is being met. Intermediate- and long-term data are needed to determine if these implants offer reliable long-term improvement in the treatment of elbow arthritis allowing for pain relief with maximal functional outcome.

IMPORTANT POINTS:

Indications are limited.
Little data exist on which to base clinical decisions.
New implants show promise for less invasive arthroplasty but are off-label in most, if not all, cases.
Use requires a complete understanding of elbow biomechanics and familiarity and comfort with multiple surgical approaches to the elbow.

CLINICAL/SURGICAL PEARLS:

Proper imaging and/or arthroscopy will allow for assessment of focal processes or lesions.
Limited approaches can be chosen for some lesions/implants.
Osteotomies (epicondylar or olecranon) allow wider access while preserving stability and enabling rapid rehabilitation.
Implantation should be done so that future revision procedures are not compromised.

CLINICAL/SURGICAL PITFALLS:

Durability of resurfacing implants is currently unknown; use should be reserved for cases where debridement will not work or has failed.
Postoperative restrictions theoretically do not need to be as extensive as those for total elbow arthroplasty, yet unrestricted use after resurfacing arthroplasty is not advisable.
Manufactured implants may not be available in the United States, may need to be custom ordered, or may be off label for use as described in this chapter.
Implantation neglecting the soft tissue or osseous constraints of the elbow may lead to failure from instability.
Wide surgical exposures with triceps takedown may lead to extension weakness. This will be more noticeable in the group of patients undergoing resurfacing arthroplasty when compared to the patients undergoing typical total elbow arthroplasty.

VIDEO:

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Animated preop video of capitellar avascular necrosis
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Lateral epicondylar osteotomy

HISTORY/INTRODUCTION/SCOPE OF THE PROBLEM

The osteoarthritic elbow that fails conservative treatment and is resistant to surgical debridement, yet does not have significant enough degenerative changes to warrant a total elbow arthroplasty (TEA), is a challenging treatment dilemma.

In a more sedentary patient, especially advanced in age, the option of total prosthetic replacement may be reasonable. In a younger, more active patient, one might consider interposition arthroplasty, but pain relief is not always reliably associated with stability for functional activities requiring strength. If the lesion or disease process has not damaged the entire articular surface, the possibility of resurfacing the involved area is appealing. This should, in theory, preserve as much normal anatomy as possible and could potentially optimize functional use of the arm, increasing the survival of the implant. If and when revision is necessary, resurfacing implants should preserve bone stock and anatomy, making revision surgery technically much like a primary total elbow arthroplasty.

Partial resurfacing of articular damage is seeing resurgence in multiple joints, with old ideas being tried once again, now with improved implants. This is evident in the elbow, where there is a growing experience and interest in prosthetic resurfacing.

Resurfacing implants in the elbow can be used for the distal humerus in its entirety, for the entire capitellum, or for just a portion of the capitellum with the proper anatomy, some isolated trochlear defects can be resurfaced. It is now possible to resurface the radial head, leaving the neck intact. There are historical reports of olecranon resurfacing but no currently available commercial implants for this indication ( Table 20-1 ).

TABLE 20-1

Implants Available for Elbow Resurfacing

Implant	Manufacturer	Available in United States	FDA Use as Described in Text	Surfaces Applicable to	Fixation Method
Sorbie-Questor	Wright Medical	Yes	Off label	Distal humerus	Cement
Lattitude	Tornier	Yes (hemi option requires custom-ordered spool)	Off label	Distal humerus (this device replaces, not resurfaces, the distal humerus)	Cement
UNI-Elbow Radio Capitellum	Small Bone Innovations	Yes	Off label	Entire capitellum	Press-fit
Lateral Elbow Replacement	Biomet	No	N/A	Entire capitellum, proximal articulating surface of radial head	Press-fit
Hemicap	Arthrosurface	Yes	Off label	Partial capitellum, partial trochlea	Morse taper into titanium screw

All of these currently available implants are commercially produced, but if available in the United States they are considered “off label” for the uses described in this chapter. This denotes that the U.S. Food and Drug Administration (FDA) has given approval to the manufacturer to market the device for specific limited uses, and use other than what has been approved cannot be promoted or marketed.

Clinical situations where resurfacing may be considered in the elbow are not common, but when they do occur, other reconstructive options are few.

As with many options for arthritis, short of total prosthetic replacement, the concepts are not new. Stevens patented a stemless distal humerus resurfacing implant in 1970 and reported on early results in 10 elbows in 1974. This device was based on an anatomic study of more than 100 elbows; the articular design was intended to replicate normal anatomy; and, as expected, the articular aspect is similar to current designs. Little was written until renewed interest sparked by Jeff Hughes’s experience with a stemmed resurfacing device for distal humeral fractures. There is one case report in the literature of a hemiarthroplasty of the distal humerus with survival of more than 20 years, demonstrating that the native proximal ulna and radial head can tolerate articulating with a metallic device.

Current devices are available to resurface the distal humerus. Complete distal humeral resurfacing can be accomplished using the Sorbie-Questor implant (Wright Medical Technology, Inc., Arlington TN; Fig. 20-1 ). The humeral component was designed to replicate normal distal humeral articular geometry, such that it readily articulates with the native proximal radius and ulna. The device requires removal of the distal humeral subchondral bone, leaving the epicondyles and collateral ligament attachments intact. There is an intramedullary stem, which is grit blasted and angled to go up the humeral canal. Use of this device is intended with a proximal ulna component (polyethylene liner on a metallic base/stem) and an optional radial head component. Use without these other components (as a hemiarthroplasty) is “off label.”

Similar in result, although more of a distal humeral replacement, the Lattitude (Tornier, Montbonnot France) humeral component can be used “off label” in isolation. This device requires removal of the distal humerus but retains the epicondyles. The standard-bearing surface is nonanatomic, but an anatomic surface can be obtained (by prescription, as a custom order in the United States or noncustom outside of the United States) and used because of the modularity of the device. Further discussion of this implant is beyond the scope of this chapter because it is not truly a resurfacing implant.

The UNI-Elbow Radio Capitellum marketed by Small Bone Innovations, Inc. (Morrisville, PA) was designed for complete replacement of the lateral elbow articulation, consisting of a resurfacing metallic implant for the capitellum, mated with a polyethylene insert in a metallic radial head replacement ( Fig. 20-2 ) The radial head component is a complete replacement and does not constitute a resurfacing implant. Use of just the capitellar component as a hemiarthroplasty is considered “off label.”