Mid-Carpal Hemiarthroplasty S.W. WOLFE , E. JANG (NE W YORK ), G. PACKER (SOUTHEND -ON -S EA , UK), J.J. CRI S CO (PROVIDENCE , RI) Historical Perspective these procedures has been demonstrated to halt the progression of arthritis, but each has been demonstrated to provide Wrist arthritis, whether caused by trauma, symptomatic relief of pain and return to instability, or inflammatory arthropathy, is functional activities, often for prolonged one of the most common conditions periods [9]. treated by hand surgeons. The manage­ ment of wrist arthritis varies with the Arthrodesis eliminates arthritic joints, severity and etiology of the pathology, and as such, is a more permanent with the common goal of achieving pain­ solution. Total arthrodesis has long been free function. The progressive nature of a mainstay in the surgical treatment of arthritis dictates that while any number severe wrist osteoarthritis because of its of conservative treatments may be relative ease of execution, durability of effective in relieving symptoms, continued symptom relief, and predictability of loading of an arthritic joint will result in long­term results [10, 11]. While total the need for further intervention. In wrist fusion results in predictable relief of patients with painful and dysfunctional pain, the inevitable loss of motion may arthritic wrists who have failed conserva­ result in an undesired loss of functionality tive management, surgical interventions [11, 12]. Furthermore, total arthrodesis is are generally grouped into one of three contraindicated in the patient with severe surgical categories: ablation, arthrodesis, rheumatoid arthritis involving multiple or arthroplasty. Each option has a unique joints, for whom wrist motion may be set of advantages and disadvantages. necessary for proper upper extremity function. The trade­off between pain and Ablative procedures remove arthritic motion that is achieved by total arthro­ components of the failing carpus, in an desis makes the procedure ideal for attempt to mitigate symptoms and slow patients with severe wrist arthritis and the progression of arthritis. Examples otherwise normal upper extremity joints, include: open or arthroscopic debride­ whose higher activity level might tradi­ ment and synovectomy [1], posterior tionally preclude total wrist arthroplasty. interosseous neurectomy or wrist denervation [2­4], radial styloidectomy Limited arthrodesis offers the patient an [5], distal scaphoidectomy [6, 7], and ability to preserve some wrist motion, 1 proximal row carpectomy [8]. None of while eliminating specific arthritic joints. ARTHROPL A STIES R A DIO -C A RPIENNES A number of limited intercarpal fusions cations have diminished the enthusiasm have been proposed to treat the varied with which the technique was originally presentations of wrist arthritis. Scaphoid described [20­26]. Problems caused by excision and four­corner fusion (4CF) has silicone synovitis resulted in Swanson’s gained favor as an alternative to proxi­ original silicone implants being replaced mal row carpectomy (PRC) in treating by metallic implants, but the metallic advanced­stage scapholunate and implants suffered from their own issues scaphoid nonunion advanced collapse of instability and distal component failure (SLAC and SNAC), due to the preservation [27­29]. Early reports demonstrated a of carpal height and maintenance of the dis concerting incidence of aseptic congruent native radiolunate joint. Single loosening of the distal component, parti­ cohort studies suggest a decreased cu larly in cases of inflammatory arthritis, tendency for arthritic progression and and often requiring reoperation [23, 29]. revision surgery in the arthrodesis group Furthermore, while one of the proposed when compared to proximal row carpec­ benefits of total wrist fusion was the tomy, though no longterm prospective availability of total wrist arthroplasty as a studies have been performed [13, 14]. salvage procedure, many complications For either option, wrist motion is cons­ during the conversion to total arthrodesis trained because the important midcarpal have been reported [30]. “dart­thrower’s arc” [15, 16] is largely eliminated, and compensatory motion of Although newer implants offer improved the elbow and shoulder may ensue. designs that result in “less devastating Radioscapholunate arthrodesis is an complications”, the issues surrounding attractive surgical option that preserves the distal component of total wrist repla­ carpal height as well as the critical mid­ cements have still not been completely carpal motion necessary for physiological resolved [24, 31, 32]. As a result, the motion of the wrist, but is largely confined proce dure has not matched the wide­ to isolated arthritis of the radiocarpal spread acceptance gained by its joint, and complications including non­ counterpart procedures in the hip, knee, union, midcarpal arthritis, and hamate­ and shoulder. lunate impaction syndrome have been reported [17, 18]. Rationale for wrist Total wrist arthroplasty was first described Hemiarthroplasty in 1973 by Swanson, as an alternative to wrist fusion for patients who have specific Many of the issues surrounding total needs or desires to maintain wrist motion wrist arthroplasty have been localized to [19]. At a time when total joint arthroplasty problems caused by the distal com­ was rapidly establishing itself as the ponent. Loosening of the distal implant is dominant reconstructive procedure in likely due to a combination of the thin large joints, wrist arthroplasty seemed to medullary canals found in the metacarpal be a desirable alternative for the subset bones, and the high moments expe­ of patients with severe wrist arthritis. rienced by the wrist joint during activities of daily living. In addition, traditional 2 Despite the positive characteristics of designs of total wrist arthroplasty resect total wrist arthroplasty, reports of compli­ a significant portion of the distal radius, MID-CA RP A L HE M I A RTHROPL A STY and as such, shift the wrist’s center of arthroplasty was combined with a rotation proximally. This alteration of proximal row carpectomy. wrist kinematics thus increases the moment on the distal component, poten­ Satisfactory outcomes were reported at tially contributing to distal component one and two years of followup, with relief loosening and pullout. This subtle shift in of pain in both patients. Range of motion the dynamic structure of the wrist joint in both patients was sufficient to meet results in significant changes in the Palmer’s definition of a functional wrist (a kinematics, soft tissue envelope, and minimum of 5° flexion, 30° extension, 10° musculotendinous forces of the wrist, radial deviation, and 15° ulnar deviation) which may lead to degenerative arthritis [34]. With the caveat that both patients or impaired motion. These precautions had good bone stock and soft tissue surrounding total wrist arthroplasty quality, Boyer went on to recommend the converge to impose strict activity procedure as a viable option for carefully restrictions on patients undergoing the selected patients who would otherwise procedure, as well as limitations on only be eligible for complete wrist fusion, eligibility for the procedure. As a result, but had specific needs or desires for although total wrist arthroplasty theore­ preserved range of motion. tically preserves motion of the wrist, the complications caused by the distal com­ Three months later, two small patient ponent impose a number of constraints series were presented at the 2010 on patient activity. International Wrist Investigators Work- shop (IWIW), separately by Culp and As a result, a number of surgeons began Adams. Culp reported the results of a investigating the possibility of implanting retrospective review of 16 wrist hemi­ just the proximal component of a total arthroplasty patients, at a range of wrist arthroplasty in order to avoid failure 4 months to 2.5 years followup, performed of the distal component. The first for the treatment of rheumatoid arthritis, description of the use of wrist hemi­ SLAC wrist, or Kienböck’s disease. All arthroplasty was published by Boyer et patients reported being “satisfied” with al. in June 2010, as a case report on two the outcomes of surgery, which included patients [33]. One patient was a 36­year a 22% mean increase in mean grip old woman with a 15­year history of strength, a noticeable decrease in pain, rheumatoid arthritis affecting both wrists and continued clinical and radiographic and refractory to splinting and steroid stability. Only one reoperation was injections, while the other was a 52­year required, a wrist capsulectomy to relieve old man with a 1.5­year history of stiffness [35]. persistent osteoarthritis. Both patients had specific desires to retain motion in Adams et al. combined a biomechanical the wrist. Both patients had personally study and a patient series to evaluate the experienced the loss of motion caused proximal hemiarthroplasty procedure. A by alternative treatments and requested study of 8 cadaver specimens utilized a motion­preserving procedure instead. radio­opaque markers in the capitate As a result, the two patients opted for a and radius to assess the alignment of the limited procedure wherein implantation wrist radiographically following hemi­ 3 of the radial component of a wrist arthroplasty and proximal row carpec­ ARTHROPL A STIES R A DIO -C A RPIENNES tomy. Radioulnar alignment remained midcarpal motion and the important within 2.2mm on posteroanterior