CHAPTER SYNOPSIS:
Arthritis of the wrist is a common and potentially debilitating condition. Time-tested surgical techniques consist of arthrodesis (limited or total) and resection of diseased bone. Wrist arthroplasty has been widely performed but with mixed results. As with treatment of other arthridites, the future in the treatment of arthritis of the wrist may ultimately boil down to a race between advancing arthroplasty techniques and the burgeoning field of orthobiologics and cartilage regeneration.
IMPORTANT POINTS:
Time-tested techniques of arthrodesis (partial or limited) and resection of diseased tissue are the current gold standards in treating wrist arthritis.
Total wrist arthroplasty is an option in low demand patients. Long-term results to date have been disappointing. Improvements must be made in implant design and surgical technique before this technique can be confidently recommended.
Orthobiologic research is a burgeoning field with considerable promise. Stem-cell research is at the forefront in this field, with current efforts focused toward exploring and developing techniques for articular cartilage regeneration.
INTRODUCTION
For most authors, predicting the future is often a “win–win proposition.” Such publications are often widely read because we are drawn to forecasts, and a glimpse into the future can be a very enticing subject matter. If the prediction proves correct, the author is viewed as clever, brilliant, even prophetic! If, as is frequently the case, the future fails to reflect the author’s prediction, few are likely to notice. The excitement is long gone, and readers will have already moved on to the next published sensation, once again satisfying their thirst for insider knowledge.
One would like to think that the scientific community holds itself to a higher standard of accountability. Holding authors of scientific literature accountable is something that we generally do well. Via the instruments of peer-reviewed, evidence-based publications and scientific meetings, our quality control is self-policed. Reckless authors are poorly received in the scientific community. This, of course, brings us to the quandary of quality control in commercially published texts. This chapter is not technically “peer-reviewed” nor has it been presented at a scientific meeting. Still, we attempt to write about the future … in this case the future of the treatment of wrist arthritis.
“The best way to predict the future is to invent it.” —Alan C. Kay, PhD
This message of Dr. Kay, a noted computer scientist and visionary for Apple Computer, applies well to the medical and surgical communities. Research and discovery ideally lead to practical application for patient benefit. In this chapter, we make no bold, unsubstantiated predictions. We will briefly review current surgical treatments of wrist arthritis and the direction of current research in an attempt to answer the following question: With respect to the treatment of wrist arthritis, what are we inventing ?
Arthritis of the wrist is a common and potentially debilitating condition. Causes can be idiopathic, inflammatory, posttraumatic, or congenital anatomic alterations such as Madelung’s deformity. There are essentially three possibilities for the future of surgical treatment of wrist arthritis:
- 1
Surgeons will continue to rely on time-tested motion-sacrificing surgical techniques such as arthrodesis (limited or total) and resection of diseased tissue (i.e., proximal row carpectomy).
- 2
Continued improvement in the quality and design of total wrist arthroplasty implants will allow outcomes of implant arthroplasty to equal or perhaps surpass outcomes of motion-sacrificing operations.
- 3
Practical application of orthobiologic cartilage regeneration research will eventually allow surgeons to regenerate lost articular cartilage, reversing the degenerative process and making obsolete conventional arthrodesis and arthroplasty procedures.
Clearly, the third option would be the ideal solution to this difficult clinical problem, but only time will tell if that possibility will play out as realistic. As with treatment of other arthridites, the future in treatment of arthritis of the wrist may ultimately boil down to a race between advancing arthroplasty techniques and the burgeoning field of orthobiologics and cartilage regeneration.
ARTHRODESIS AND RESECTION OF DISEASED TISSUE
Bony resection with or without total or partial arthrodesis of the wrist is the current workhorse surgical treatment for advanced wrist arthritis. Motion is sacrificed, in part, with the expectation of reliable pain relief. In general, results of these techniques are time-tested, reliable, and well documented. The most commonly used motion-sparing techniques are proximal row carpectomy and scaphoid excision with intercarpal arthrodesis. A variety of radiocarpal and intercarpal fusions have also been widely used for various patterns of focal disease, whereas total wrist arthrodesis remains the longstanding and reliable ultimate salvage procedure for all types of wrist arthritis ( Figs. 11-1 and 11-2 ). Although all wrist motion is eliminated, functional outcomes following unilateral total wrist arthrodesis are surprisingly good. The role of these traditional techniques and their modified forms in the future will be determined, in part, by the relative success or failure of the alternative techniques designed to replace them as “the gold standard.”
For more limited patterns of wrist arthritis, such as wrist degeneration secondary to carpal instability (SLAC [scaphoid-lunate advanced collapse] wrist) or longstanding scaphoid nonunion (SNAC [scaphoid nonunion advanced collapse] wrist), a variety of intercarpal fusions have been used. The most commonly used technique involves scaphoid excision with four-corner intercarpal arthrodesis (capitate-lunate-hamate-triquetrum arthrodesis) ( Figs. 11-3 and 11-4 ). Successful fusion results in predictable pain relief and partial motion preservation. Success of this operation depends on an intact radiolunate articulation, as is usually the case in most SLAC and SNAC wrists. Achieving predictable fusion of the four involved carpal bones and correcting the extended posture of the lunate is the challenge of this operation, and a variety of techniques and devices have been developed toward that end. At our institution, the triquetrum is often excised along with the scaphoid during this operation. We feel that the contribution of the ulnotriquetral articulation to wrist load transmission following four-corner fusion is negligible. Routinely removing this bone simplifies the operation and removes a potential site of nonunion.
Implant choice for stabilization of four-corner or capitolunate arthrodesis is a current area of controversy. Our preference is to use headless compression screws rather than dorsal circular plates. Future considerations for implants will include the option to use bioabsorbable plates and screws. We see no advantage in the use of bioabsorbable implants. If an implant is placed properly, its presence should have no deleterious effect on long-term outcome. Therefore, the ability for said implant to “absorb” is, in our opinion, irrelevant.
Bone grafting is left to the discretion of the surgeon. We routinely add additional autograft to our intercarpal fusions. Our choice is to harvest local distal radius cancellous bone through a dorsal approach. Alternatively, and particularly in nonsmokers, cancellous allograft cubes can be morselized and applied to the fusion site with success.
For patterns of wrist arthritis associated with preservation of the capitolunate articular cartilage, proximal row carpectomy may be applied with good long-term success ( Figs. 11-5 and 11-6 ). The radius of curvature of the capitate head is less than that of the lunate fossa of the radius. Although high contact pressures at the radiolunate articulation would seem to predispose the joint to developing arthrosis, the constant translational motion of the capitate head in the lunate fossa during wrist flexion and extension has been attributed as the reason for the lack of long-term arthritic changes observed in these patients. The high concentration of contact pressure is, in essence, distributed about the lunate fossa as the capitate head continuously translates. DiDonna and colleagues recommended proximal row carpectomy in patients older than age 35 years because their 10-year results were inferior in the younger, more active patient population. As arthroscopic techniques continue to improve for the wrist, its application will likely become more popular in proximal row carpectomy. At this time, however, open proximal row carpectomy remains, in our hands, a more time-efficient and equally effective means to the same end.
