Operative Correction of Swan-Neck and Boutonniere Deformities in the Rheumatoid Hand Martin I. Boyer, MD, MSc, FRCSC, and Richard H. Gelberman, MD Abstract A swan-neck or boutonniere deformity occurs in approximately half of patients to evaluate for atlantoaxial subluxa- with rheumatoid arthritis. The cause of boutonniere deformity is chronic syno- tion, basilar impression, and subaxial vitis of the proximal interphalangeal joint. Swan-neck deformity may be caused instability. Previous radiographs, if by synovitis of the metacarpophalangeal, proximal interphalangeal, or distal available, are compared with current interphalangeal joints. Numerous procedures are available for the operative films for signs of progressive instabil- correction of these finger deformities. The choice of surgical procedure is depen- ity. If the tip of the dens cannot be dent on accurate staging of the deformity, which is based on the flexibility of the adequately visualized on plain lateral proximal interphalangeal joint and the state of the articular cartilage. The radiographs of the cervical spine or patientÕs overall medical status and corticosteroid use, the condition of the cer- base of the skull, magnetic resonance vical spine, the need for operative treatment of large joints, and the presence of imaging of the cervical spine is indi- deformities of the wrist and metacarpophalangeal joints must also be considered cated. when planning treatment. In the later stages of both deformities, soft-tissue Regional anesthesia, such as axil- procedures alone may not result in lasting operative correction. lary block, is preferable to general J Am Acad Orthop Surg 1999;7:92-100 anesthesia for correction of finger deformities because postoperative pain control is better and systemic side effects are fewer. General Finger deformities are common in nation of deformity.3 Within the anesthesia is required if concurrent persons with rheumatoid arthritis, broader context of a patientÕs med- procedures are to be performed, which affects 3.2% of Americans ical status, the condition of the cer- such as the harvest of an iliac-crest between the ages of 18 and 79 vical spine and the larger joints of bone graft. However, the presence years.1 The incidence of uncor- the upper and lower extremities and of instability of the cervical spine on rectable swan-neck and bouton- the presence of coexistent deformi- preoperative evaluation may influ- niere deformities is estimated to be ties of the wrist and hand must be ence selection of the type of general between 8% and 16% during the considered in the timing and selec- anesthetic utilized. first 2 years after the onset of sys- tion of operative procedures. temic disease, and the prevalence of finger deformities in patients with established rheumatoid arthritis is Preoperative Assessment Dr. Boyer is Assistant Professor, Department of approximately 14% for swan-neck of the Cervical Spine and Orthopaedic Surgery, Washington University School of Medicine, St Louis. Dr. Gelberman is deformities and 36% for bouton- Other Joints Reynolds Professor and Chairman, Department niere deformities.2 Often the most of Orthopaedic Surgery, Washington Univer- visible manifestations of rheuma- The cervical spine, which is common- sity School of Medicine. toid arthritis, such deformities can ly affected in patients with rheuma- be painful and can impair finger toid arthritis, should be evaluated in Reprint requests: Dr. Boyer, Department of and hand function significantly. all patients considered for hand Orthopaedic Surgery, Washington University School of Medicine, Suite 11300, 1 Barnes Principles guiding the operative surgery. The evaluation focuses on Hospital Plaza, St Louis, MO 63110. correction of deformities in the radiographic changes, neurologic hands of patients with rheumatoid signs and symptoms, and neck pain. Copyright 1999 by the American Academy of arthritis focus on relief of pain, Anteroposterior, lateral, and flexion- Orthopaedic Surgeons. improvement of function, and elimi- extension lateral views are obtained 92 Journal of the American Academy of Orthopaedic Surgeons Martin I. Boyer, MD, MSc, FRCSC, and Richard H. Gelberman, MD The hip, knee, shoulder, and ulnae syndrome), and rupture of the Flexor tenosynovitis is indicated elbow joints are commonly involved extensor pollicis longus is essential. by palpable mobile fullness in the in rheumatoid arthritis. The effect Evaluation of the MCP joints for distal volar forearm. Flexor teno- of arthritis on large joints influences active synovitis and the presence of synovitis of the finger is identified on the ability of a patient to care for ulnar drift and volar subluxation is the basis of three findings: swelling, himself or herself, to carry out activ- also critical. Wrist, DRUJ, and MCP discrepancy between active and pas- ities of daily living, and to partici- joint abnormalities are important not sive motion of the finger, and palpa- pate in postoperative hand rehabili- only because they may be of greater ble crepitus along the course of the tation and therefore may necessitate functional significance to the patient flexor tendon on active and passive operative correction of large-joint than the finger deformities, but also flexion of the digit. Extensor teno- arthritis before operative correction because they may directly contribute synovitis is signaled by the presence of finger deformities. For instance, to the development of those defor- of persistent swelling and crepitus the hand and wrist must be able to mities by altering the extent and along the course of the long extensor withstand the added upper-extremity direction of in vivo forces generated tendons both proximal and distal to forces required to use walking aids by flexor and extensor muscle con- the extensor retinaculum. during rehabilitation of the lower traction in the fingers. In addition, Flexor or extensor tendon teno- extremity. Stabilization of the wrist wrist and MCP joint deformities synovitis or rupture at the wrist or thumb metacarpophalangeal may influence the longevity of cor- level must be identified, as correc- (MCP) or interphalangeal joints by rections of finger deformities. tion of the finger deformity without arthrodesis facilitates the patientÕs concomitant operative correction of rehabilitation after hip or knee wrist synovitis and tendon rupture arthroplasty by allowing pain-free Basic Assessment of Finger does not increase active range of use of walking supports, such as Deformities motion. Proximal tendon ruptures walkers, crutches, and canes. are diagnosed by visual inspection Oral corticosteroid administra- Once the physical examination of (i.e., if proximal muscle contraction tion presents special concerns, the large joints, wrist, and hand has is seen without finger motion) or including the risk of postoperative been completed, clinical examina- palpation (i.e., if tendon excursion wound infection and an increase in tion of the fingers is carried out. is absent distal to the site of a rup- overall healing time of soft tissues. The resting positions of the proxi- ture). The tenodesis effect of wrist If a general anesthetic is required mal interphalangeal (PIP) and dis- flexion and extension on digital for a patient taking oral cortico- tal interphalangeal (DIP) joints are motion is assessed to rule out ten- steroid medication, the preopera- noted, and the active and passive don ruptures at the wrist level. If tive administration of intravenous ranges of motion of each joint are passive wrist flexion fails to elicit corticosteroids is indicated, fol- recorded. The initiation of flexion extension of the fingers, rupture of lowed by a tapering-dose regimen is observed while examining the the long extensor tendons should postoperatively. active ranges of motion, because be suspected. Adhesion of a rup- difficulty in initiating PIP joint flex- tured tendon to the surrounding ion is associated with early swan- tissue proximal to the wrist may Clinical Evaluation of the neck deformity. decrease the accuracy of this test. Wrist and Hand Involvement of the PIP and DIP The Bunnell test of intrinsic ten- joints in the rheumatoid process is don tightness is performed in all fin- Because collapse of the carpus into assessed. Bulging of the joint indi- gers of patients with rheumatoid supination, volar translation, and cates the presence of an effusion and arthritis. It has special relevance in ulnar translocation occurs often and implies possible capsular attenua- patients with early swan-neck defor- is most easily noted on visual tion and laxity. Crepitus with joint mities, as it assesses the relative con- inspection, examination for active motion indicates articular cartilage tribution of tight intrinsics to the synovitis and deformity of the radio- damage. In cases of boutonniere genesis of the deformity. While the carpal joints and the distal radioul- deformity, the skin is assessed for MCP joint is held in the extended nar joints (DRUJs) should be carried tightness volarly over the PIP joint position, the degree of resistance to out routinely. Inspection for dorsal and attenuation over the dorsum of passive flexion of the PIP joint is subluxation of the distal ulna, rup- the PIP joint. In cases of swan-neck determined (Fig. 1, A). Increased ture of the extensor carpi ulnaris ten- deformity, the skin is examined for resistance to passive PIP joint flexion don and the extensor tendons of the tightness over the PIP joint dorsally signifies relative shortening of the small and ring fingers