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Address the whole patient; treatment is based on patient needs, not radiographs alone.
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Surgeon–therapist–patient cooperation is essential.
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Meticulous surgical technique and meticulous therapy are both necessary.
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Arthrodesis is still a reasonable option in many patients.
Implant arthroplasty represents a unique challenge to the surgeon and therapist. Potential candidates for this procedure may present with only one or two involved joints or with severe, disabling disease. Some patients may cope relatively well with their disability, whereas others are devastated. The team of surgeons and therapists must determine which patients are suitable candidates for implant arthroplasty and which might be better served by nonoperative, supportive care. Innovative changes in implant design require the surgeon to carefully select which implant is best for each individual patient. Similarly, advances in medical treatment in rheumatoid arthritis (RA), specifically anti–tumor necrosis factor drugs, can significantly alter the course of the disease in patients such that they may never require surgical treatment. Even if they do, soft tissue reconstruction may be the better choice. Surgeons must remember that operative intervention in the rheumatoid patient is palliative, and while beneficial to the patient, joint replacement arthroplasty is not a cure. The surgeon and therapist should counsel patients in advance to ensure that patients have a thorough understanding of what is involved in joint replacement and the rehabilitation program. They should be advised that close follow-up will be necessary after surgery. The patient must also adhere to an ongoing program of joint protection, both preoperatively and postoperatively, to ensure that the replacement will last as long as possible.
Many types of arthritis can affect the hand and upper extremity. The etiology is varied, from severe, disabling RA with systemic manifestations to other collagen vascular diseases, such as psoriatic arthritis, lupus, or ankylosing spondylitis. Arthritis in the hand and upper extremity also may be caused by diseases such as gout, avascular necrosis (Preiser’s and Kienbock’s diseases), post-traumatic arthritis, and osteoarthritis (OA). Selected conditions are briefly reviewed in the following section.
Selected Arthritic Conditions
Osteoarthritis
Osteoarthritis is perhaps the most common arthritic condition in the hand and upper extremity. It is estimated that as much as 40% of the adult population may be afflicted; however, only 10% seek medical attention and 1% are disabled by arthritis. As with other types of arthritis, there may be a genetic predisposition that influences the structure and metabolism of articular cartilage; however, the development is also due to traumatic instability and aging, with the latter arguably secondary to microtrauma of day-to-day use. The term OA is somewhat of a misnomer, in that there is very little if any inflammatory component to the disease, particularly when compared to other conditions such as RA and gout. The term osteoarthropathy may be more accurate.
Clinically, with OA, patients complain of pain as the day progresses and with usage of the extremity. Symptoms therefore become most severe late in the day and into the evening. Patients with OA frequently awaken in the morning feeling relatively pain-free in contrast to patients with RA, who experience stiffness and discomfort in the morning.
The joints most commonly affected by OA are the distal interphalangeal (DIP) joints of the fingers and the basal joint of the thumb. The clinical appearance of advanced OA in the DIP joint is one of angular deformity secondary to instability and relatively large osteophytes referred to as Heberden’s nodes. The DIP joints often present with a burning-type pain relieved by nonsteroidal medication, oral or topical, and paraffin baths. Soaking in hot water often makes the fingers feel better but may result in swelling. In contrast, the heat from paraffin is imparted to the fingers through a thick heated mold of wax and when a paraffin treatment is followed with Coban (3M, Minneapolis, Minnesota) wrap the swelling in the finger may be reduced. Education of the patient is also important in OA, particularly in terms of joint protection principles and counseling patients to avoid certain tasks such as heavy, repetitive lifting. Surgical intervention may be considered, and arthrodesis is the most predictable and effective procedure for the DIP joint of the finger. Osteophytes are removed and the overall appearance of the finger improved at the expense of whatever range of motion (ROM) has been spared by the arthritis.
OA of the proximal interphalangeal (PIP) joint is less common than OA of the DIP joint but when present may cause more functional limitation of the hand and finger. As with the DIP joint, activity modification, orthoses to support the involved joint for rest and symptom relief, and Coban may be helpful. Coban can be combined with paraffin treatment to control swelling in the joint and relieve symptoms. Surgical intervention of the PIP joint, as with the DIP joint, may best be accomplished by arthrodesis, although at the PIP joint arthrodesis significantly compromises finger function. Arthroplasty may be considered and has more predictable long-term satisfactory results in the long and ring fingers as the border digit PIP joints are subject to increased stress in loading and are more prone to early failure. Silicone arthroplasty has stood the test of time and provides predictable pain relief with limited motion.
Finally, the radiocarpal joint may be involved in OA, often from a scapholunate injury, but also from conditions such as scapholunate advanced collapse deformity and primary OA of the radiocarpal joint. Scaphoid fractures, when allowed to proceed to nonunion, are also a common cause of radiocarpal arthritis. Illustrations of joint replacement arthroplasty for OA follow in this chapter.
Scleroderma
Scleroderma is a systemic autoimmune disease that begins by affecting the small vessels of the hands and multiple organ systems and leads to progressive fibrosis of connective tissues and particularly severe deformity in the hand. The acronym CREST is often applied to the disease and refers to calcinosis of the soft tissues, Raynaud’s phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia, all of which are seen in severe forms of the disease. Contractures are particularly problematic in the PIP joint and metacarpophalangeal (MCP) joint, with the usual deformity being flexion contracture of the PIP joint ( Fig. 107-1 ). Surgical correction is possible but involves considerable risk in terms of wound healing and infection. When planning a release of the PIP joint, it is important to remember that the skin is the structure that usually contributes most to the contracture. Swan neck deformity may be seen at the PIP joint in scleroderma, but usually only in conjunction with MCP joint flexion contracture and intrinsic tightness. The therapist and/or hand surgeon should be aware that certain characteristics of scleroderma may “overlap” with other rheumatologic diseases such as dermatomyositis, systemic lupus erythematosus, and RA and particular attention paid to the deformity seen. The surgeon should be aware that while some of the risks such as ischemia and the potential for tissue loss may not pose as great a risk in patients with this overlap syndrome, the severity of the contracture and the absence of plasticity in the tissues make surgical correction of any deformity in patients with this clinical picture of systemic sclerosis or any variation on this diagnosis extremely difficult. While implant arthroplasty in the PIP joint of patients with scleroderma is possible and has been reported with satisfactory results, the safer, conservative surgical approach, particularly for severe PIP joint contractures, is PIP joint arthrodesis.
Psoriatic Arthritis
Psoriatic arthritis, as its name implies, begins with a scaly red rash and progresses to involve the joints, although the reverse may be true. Typically the distal phalanx and DIP joints are involved, and as the disease progresses, the distal bone proliferates while the proximal bone tapers, leading to the “pencil in cup” deformity described with this disease. In severe, full-blown cases, destruction of the bone and joints can become so great that the soft tissues of the fingers collapse on themselves, leading to the descriptive term “opera glass hand.” Surgical treatment may play a role; however, joint replacement is extremely difficult due to the narrow bone canals in patients with psoriatic arthritis ( Fig. 107-2A–C ).
Surgical Treatment of the Wrist
Rheumatoid patients may be ideally suited for joint replacement arthroplasty of the wrist, especially if they have polyarticular involvement (e.g., wrist, hand, finger, elbow, shoulder) in which preservation of motion at the wrist is important. Patients with severe pancarpal OA and good bone stock may be even better candidates.
In the 1970s, both Meuli and Volz developed new implants for wrist replacement. These were both metal prostheses with a plastic ball-and-socket type of joint that were designed to be cemented in place in the distal radius and metacarpal. Success with these prostheses was short-term. Failure occurred when the distal stem of the prosthesis eroded through the cortex of the much softer bone. In some instances the implant would become loose and painful, with failure usually occurring in the distal metacarpal implant interface ( Fig. 107-3A, B ). When bone stock was relatively good, such as seen in OA, and when a stable press fit could be obtained in the metacarpal, the biaxial implant would often last for years without the need for revision ( Fig. 107-3C ). Clinical research continued with metal on high-density polyethylene implants. Predictably, subsidence and/or loosening of the distal component has led to relatively high failure rates in all of these metal prostheses as a result of the disparity of elastic modulus between bone and metal, particularly in osteoporotic rheumatoid bone. More recent designs have the distal component fixed to the carpus with lag screws to prevent motion and subsidence. Preliminary results are promising ( Fig. 107-3D ).
In the 1970s, Swanson introduced silicone implant arthroplasty. The silicone joint had a proximal stem that was inserted into the radius, a flexible hinge, and a distal stem that was inserted through the capitate into the long finger metacarpal. This implant was one solid unit with the same dimensions as the replacement for small joints in the hand. In low-demand patients and patients with vocational or avocational needs that require wrist motion, this implant may be a reasonable treatment option. In some patients with RA, bone stock may be so deficient that successful fusion is unlikely ( Fig. 107-4A–C ). Silicone replacement of the radiocarpal joint then becomes the preferred treatment of choice. The material properties of silicone are closer to that of bone; therefore, the silicone joint and stem are less likely to subside into the metacarpal distally or the radius proximally. Indications for silicone wrist replacement include pain with attempted wrist motion, decreased motion, instability, and deformity. Radiographs should reveal pancarpal arthritis with enough remaining bone stock to support the implant; specifically, an intact distal radius cortex and similar residual bone stock in the long finger metacarpal to support the implant. In a series of 23 patients representing 26 Swanson radiocarpal replacements, Davis, Weiland, and Volenec-Dowling noted that patients had significant functional improvement in activities that require wrist extension. No improvement was seen in activities requiring strength or fine motor control. Capsular reconstruction and tendon transfer to balance the wrist were important in the success of the arthroplasty.
When performing implant arthroplasty of the wrist, the surgeon should be certain that the wrist does not become secondarily infected. In addition to careful, delicate tissue handling at the time of surgery and prophylactic antibiotics, synovial pathology from the surgery should be studied by standard hematoxylin and eosin technique. If infection is suspected, the tissue should be Gram-stained and cultured. Despite more compatible material properties with bone, silicone wrist implants also fail with time. This may lead to recurrent deformity and possibly silicone synovitis ( Fig. 107-5A–C ). Combined metal–polyethylene prostheses may also fail. Fracture of the hinge mechanism of a trispherical total wrist has been reported as causing synovitis secondary to wear debris from titanium, cement, and polyethylene.
The optimal candidate for wrist replacement has pancarpal arthritis and relatively normal bone stock. The patient must have a compelling need for replacement rather than fusion, limited fusion, or a “shelf procedure.” Clinically, this usually is a patient with severe bilateral disease that affects both elbows and shoulders. In such cases, from 1986 through 2004 the author chose the biaxial wrist replacement ( Fig. 107-3C ). This prosthesis has two components, with a proximal articulation that is press fit in the distal radius and has a concave surface. Distally, the stem passes through the capitate, with the stem extending to the long finger metacarpal. Its articular surface is convex. The bone–metal interface is less than optimal in terms of material properties, as cobalt chrome has a much higher elastic modulus than bone, but a good press fit should be stable and allow for bone ingrowth on the surface of the implant. However, the concave proximal polyethylene surface of the joint articulating with the cobalt chrome distal convex side of the joint provides an ideal coefficient of friction and improved joint biomechanical design. Motion with this prosthesis is generally better than with silicone replacement. While this prosthesis often provided a successful outcome in the short term, many implants have failed with time as the result of the distal stem migrating through the long finger metacarpal or simply loosening and becoming painful (see Fig. 107-3A, B ). More recent implant designs have improved fixation in the distal stem by adding lag screw fixation to the distal carpus (see Fig. 107-3D ).
Technique
The extensor retinaculum is exposed through a longitudinal incision in line with the long finger metacarpal, beginning at its base and crossing the wrist joint, extending 4 to 5 cm proximal to the wrist. The retinaculum is split longitudinally to preserve the distal ulnar half of the flap to cover the radiocarpal joint and the proximal half, which serves as a dorsal pulley for the extensor tendons at the close of the procedure. The interval between the extensor pollicis longus and extensor digitorum communis (third and fourth extensor compartments) is opened and the tendons protected and retracted with a 
-inch Penrose drain. The radial wrist extensors—extensor carpi radialis longus and extensor carpi radialis brevis—are included with the extensor pollicis longus and reflected radially. The dorsal capsule of the wrist is opened with a T -shaped incision, and a proximal row carpectomy is performed. Care must be taken to protect the underlying median nerve and flexor tendons because the lunate and triquetrum usually have subluxed volarly and lie in juxtaposition to the median nerve and flexor tendons. The end of the distal radius and the proximal half of the capitate are removed with an oscillating saw. A canal through the center of the capitate, extending into the long finger metacarpal, is created with a sharp awl. The canal is then enlarged with reamers of progressively larger sizes until the cortex of the metacarpal is reached. The distal radius then is reamed to accommodate a similar-sized component. A trial fit is performed, and the stability of the prosthesis is assessed. The center of wrist joint motion is in the proximal third of the capitate. The closer the center of rotation of the prosthesis is to the original normal center, the better the balance of the prosthesis and, ultimately, the better the function of the replacement. The distal component (in the case of the SBI and KMI prosthesis [Kineticos Medical Inc., Carlsbad, California]) is anchored to the distal carpal row with cancellous screws in the capitate and trapezoid to maintain stability and prevent subsidence. This is in contrast to the biaxial prosthesis, which was secured distally through a press fit in the capitate and long finger metacarpal as well as a short spike anchoring the prosthesis in the trapezium. To protect the extensor tendons, the distal half of the extensor retinaculum that was mobilized at the beginning of the procedure is used to cover the prosthesis and is sutured to the remaining capsule on the ulna. The skin is closed with interrupted vertical mattress sutures of 4-0 or 5-0 nylon over a small rubber drain.
Postoperative Management
0 to 4 Weeks
At 24 to 48 hours the dressing is changed and the drain is removed. At this time the patient is placed in a volar wrist support orthosis. The sutures are removed between 1 and 2 weeks. Depending on the stability of the prosthesis, gentle active range of motion (AROM) for the wrist may be started as early as 2 weeks postoperatively. The surgeon and therapist need to discuss and review factors that influence the timing of initiation of wrist range of motion, such as poor bone stock or weakened or frayed tendons, as well as the specific procedure and expected outcome. The surgeon’s skill as regards prosthetic insertion with careful closure affects the timing of rehabilitation. Under ideal circumstances, a 40- to 60-degree arc of total active flexion and extension of the wrist may be obtained. Supervised outpatient hand therapy sessions at this time are scheduled as needed. The patient should have an established home program and should be provided with information regarding joint protection. Care should be taken to address the patient’s shoulder, elbow, and neck to maintain ROM and function and to avoid undue stress on the contralateral extremity.
During the first 4 weeks the patient wears the volar wrist support orthosis most of the time, removing it for bathing and exercises. The orthosis positions the wrist at 10 to 20 degrees of extension and allows for full flexion and extension of the digits and opposition of the thumb to the small finger. If the extensor tendons are repaired, the MCP joints are supported in the wrist orthosis in a neutral position to protect the tendons for 3 weeks or more postoperatively, and initiation of wrist motion may be delayed. After 3 weeks, if a lag develops or persists, use of the orthosis for another 1 to 2 weeks is recommended.
Techniques to promote healing of the incision and to manage postoperative swelling are reviewed at this time. Joint protection techniques are reinforced as well.
4 to 8 Weeks
Gentle active motion of the wrist continues with care to avoid overexercise and to monitor for extensor lag of the digits. Edema control and scar management are part of the program, as are modalities to help with swelling, stiffness, and pain. Light grip activities, such as the weight well with no resistance and limited repetitions, can help facilitate increased ROM.
8 to 10 Weeks
By 8 to 10 weeks postoperatively, a light strengthening program may be initiated. This should begin with isometric exercise followed by progressive resistive exercise with a 1-pound (0.4 kg) weight and with education of the patient on biomechanically sound joint protection principles. A wrist orthosis, either custom-made or prefabricated, may be used for heavy activities, such as gardening, or during extended use. Long-term outcomes are improved with a permanent lifting restriction of 10 pounds (4 kg) after total wrist arthroplasty.
Replacement of the Metacarpophalangeal Joint
Replacement of the MCP joint of the fingers typically is reserved for the patient with severe RA, joint space narrowing, ulnar drift, volar subluxation, and/or intrinsic tightness ( Fig. 107-6 ). Some authors recommend fusion or other salvage procedures of the MCP joint of the index finger in patients with RA to increase stability in pinch and to prevent ulnar deviation by the ulnar deforming forces. This is reasonable with normal PIP and DIP joint function. Salvage procedures following failed implants with bone stock loss or infection include various modifications of soft tissue arthroplasty. When reasonable bone stock remains, the Fowler arthroplasty is recommended, in which the metacarpal is cut in the shape of a chevron and intercalated in a V -shaped cut in the base of the proximal phalanx. Leonard Goldner has stated that the best results from soft tissue arthroplasty exceed the best results from silicone replacement, but the latter yields more consistent results.
Currently, the pyrolytic carbon MCP joint implants as well as the SBI surface replacement arthroplasty re-create a semblance of more normal anatomy and may offer patients improved function in the long term. In the pyrolytic prostheses, the construct is one of an isotropic carbon coating over a graphite substrate with wear properties similar to ceramic. These implants have separate components for the proximal phalanx and metacarpal and require attention to detail in collateral ligament reconstruction at the close of the procedure to maintain stability. The SBI implants are similar in that they are designed with separate proximal and distal components that require ligamentous stability for success. The material used in these prostheses, however, is titanium for the proximal convex joint surface and high-density polyethylene for the concave distal surface, similar to total knee prostheses. Results for both prostheses have been reported to be successful, with reasonable survivorship statistics when the implants are used in patients with minimal deformity. When joints are dislocated and have radiographic signs of cortical bone loss, traditional constrained silicone implants should be used.
Finally, in patients with RA that is well controlled with anti–tumor necrosis factor drugs, soft tissue reconstruction such as extensor tendon realignment and synovectomy with crossed intrinsic transfer may be the ideal surgical approach, as these patients have a lower risk of recurrent attacks of RA on the MCP joints and other joints than before the introduction of these new medications.
Preoperative Evaluation
Ideally the patient will have been evaluated preoperatively, including documentation of function, ROM, and pinch and grip strength. An assessment of motor function is important to identify possible peripheral nerve involvement. A description of the effects of the disease process on the upper extremity should be included, with special note of the presence of any deformities and joint contractures. A sensibility evaluation is important, because many patients with arthritis have carpal tunnel syndrome secondary to thickened tenosynovium within the carpal tunnel, resulting in secondary compression of the median nerve. An assessment of activities of daily living (ADLs), noting whether the patient uses any assistive devices or ambulatory aids, and vocational assessment are performed. Standardized tests such as the Jebson Taylor Hand Function Test may be used.
Because rehabilitation after MCP joint replacement requires prolonged therapy and orthotic positioning for 3 to 6 months, pertinent social data (i.e., support at home for meal preparation and self-care postoperatively) and insurance benefits are all important to consider during the preoperative evaluation. The goal of the therapy program must be patient-focused, on pain relief, improvement of cosmesis, restoration of a functional arc of motion, and satisfactory alignment of the joint. Patients and their insurance carriers need to realize that at least weekly visits are necessary to achieve this goal.
Technique
The extensor mechanism of the finger is located through a dorsal transverse incision just proximal to the MCP joint. When only one MCP joint is being replaced, a longitudinal incision along the ulnar side of the finger may be considered. Usually, the central extensor tendon at this level is subluxed toward the ulna, and the radial sagittal fibers are attenuated. Beginning with the index finger, a longitudinal cut is made through the ulnar transverse and oblique fibers of the dorsal apparatus of the extensor mechanism reflecting the tendon to the radial side of the MCP joint. The ulnar intrinsic tendon insertion into the lateral band of the extensor mechanism and the proximal phalanx is carefully identified and released. When the MCP joint is subluxed volar and ulnar to its normal position, the ulnar intrinsic is also located more volar and must be distinguished from the ulnar digital nerve. The dorsal capsule is opened, and a synovectomy is performed. If the collateral ligaments have been spared by the disease, they are carefully reflected from the metacarpal, and the metacarpal head is removed with an oscillating saw ( Fig. 107-7 ). The saw cut is just distal to the origin of the collateral ligament, preserving the origin for reconstruction. The amount of bone resected may vary depending on the degree of bone erosion on the dorsum of the proximal phalanx. In general, the more bone erosion from the proximal phalanx, the less bone is resected from the metacarpal to preserve the correct amount of space for the implant when part of the proximal phalanx is removed as well. The palmar plate is released and the proximal phalanx is “delivered” dorsally into the field and flexed to facilitate reaming. The metacarpal shaft and the proximal phalanx are reamed with a sharp awl, and the cavity is enlarged to accept an appropriate-sized prosthesis. The fit should be snug and not compromise the minimal amount of bone stock. The procedure is identical for each of the digits, except for the small finger, in which the abductor digiti minimi should be carefully separated from the flexor digiti minimi and released, while the flexor digiti minimi is preserved to maintain grip strength. A trial prosthesis is inserted into each finger to be replaced, and joint stability is evaluated. If acceptable, the permanent prostheses are inserted into each finger as the trials are removed. Care is taken to grasp the prosthesis with smooth forceps or a hemostat to avoid damaging the surface of the implant. Stainless-steel grommets may be used as an interface between the silicone and bone to protect the implant and afford additional stability. If possible, the collateral ligaments are preserved by primary suture if the origin has been preserved. If not, then the distal ligament may be sewn to the periosteum or through drill holes using 4-0 absorbable suture. The dorsal apparatus is relocated over the MCP joint. The radial side of the sagittal fibers at this level is then stabilized in one of three ways: The redundant fibers may simply be imbricated on themselves and sutured with a braided nylon. A second technique is to longitudinally cut the radial sagittal fibers and overlap them in a “pants-over-vest” fashion. Finally, a section of the tendon may be split longitudinally and wrapped around the ulnar side, anchoring the tendon to a small drill hole on the radial side of the metacarpal. Alternatively, the same distally based slip may be sutured to the remaining thick capsule at the base of the proximal phalanx as described by Feldon et al. In 1973, Swanson reported reconstructing the radial collateral ligament with the radial half of the palmar plate anchored to a drill hole. In the ring and small fingers, the sagittal fibers are stabilized, but formal repair of the collateral ligaments is not necessary as it is in the index and long fingers, and the postoperative orthotic positioning program is expected to keep the tendon and joint well aligned for 8 to 12 weeks while the tendon heals and a fibrous pseudocapsule forms around the implant. The skin incision is closed loosely with interrupted vertical mattress sutures of 5-0 nylon over a small rubber drain. A bulky dressing with 4 × 4 gauze and a cling wrap is applied. This is followed by dorsal and palmar forearm-based orthoses extending to the fingertips. Patients may be hospitalized for 24 to 48 hours, depending on the amount of postoperative pain they experience, the extent of systemic disease and associated medical problems, and family support. Parenteral antibiotics should be given during the perioperative period, ideally 1 hour before the tourniquet is inflated and for two to three doses postoperatively. A dressing change is performed on the first or second postoperative day. The wound is inspected, the drain is removed, and the patient is placed back in a static or a dynamic orthosis ( Fig. 107-8A–C ), depending on the degree of instability noted at the time of surgery. Revision MCP joint arthroplasties usually are kept in a cast or static orthosis for 4 to 6 weeks, while a pseudocapsule forms around the implant. Both Ascension (Ascension Orthopaedics, Austin, Texas) and Avanta (Avanta Orthopaedics, Inc., Morrisville, Pennsylvania) MCP joint replacements (see below) are designed primarily for MCP joints affected by OA or post-traumatic OA; however, they can be used in patients with RA. In these patients, the surgeon needs to remember that soft tissue balance is critical to the success or failure of these implants. Patients with severe ulnar deviation and volar subluxation may be better served with standard silicone implants. In younger patients, however, and in patients that the surgeon feels comfortable with joint stability postoperatively (or even preoperatively), Ascension or Avanta joints may be considered and may in fact serve the patient better in the long term by not failing mechanically. The surgical approach is basically the same for these implants, with the main difference between these and the standard silicone implant being that the Ascension and Avanta implants consist of two separate proximal and distal components instead of the single-component flexible-hinge Swanson-type prosthesis. The proximal component in each replaces the metacarpal head, and the distal component replaces the base of the proximal phalanx. Intramedullary stems stabilize both proximal and distal components, and both proximal and distal components are stabilized using a press-fit technique. Guided osteotomies unique to each prosthesis are used first on the metacarpal head and then on the proximal phalanx. The medullary canals are then broached to the desired size. The proximal phalanx is generally broached first, as it determines the size of the implant. The metacarpal is then broached to the appropriate size as well as remembering a chamfer cut on the volar surface of the distal metacarpal, following the metacarpal guide. It is theoretically possible to insert variable size metacarpal and proximal phalangeal components. Trial implants are placed and checked for stability, and if stable and satisfactory, the final implants are impacted in place. In our experience, preservation of the radial and ulnar collateral ligaments is key to preventing ulnar and volar subluxation in either the long or short term. Figure 107-9A–F depicts a 72-year-old woman with advanced changes of RA in both hands, the left somewhat worse than the right. Since she was right hand–dominant and the changes were less severe in this hand, she underwent MCP joint arthroplasty with Ascension pyrocarbon implants. The implant to the long finger MCP joint dislocated and required closed reduction and percutaneous K-wire fixation for 6 weeks to allow the reconstructed collateral ligaments to heal. She is now 5 years postreplacement and has undergone silicone replacement arthroplasty on the more deformed, nondominant contralateral left upper extremity. The Avanta implants can be cemented in place, while the Ascension implants are designed for press fit only.
Postoperative Management Following Metacarpophalangeal Joint Arthroplasty
Hand function and patient satisfaction after MCP joint implant arthroplasty are based on a goal-oriented and structured postoperative therapy program, usually lasting 3 to 6 months. Considering the individual patient’s unique goals as the treatment program is developed is important for a successful outcome. Beckenbaugh stated in 1983: “the goal of implant arthroplasty is never a normal or near normal functioning articulation, but rather a painless arthroplasty with a useful arc of motion.” An experienced hand therapist who is skilled in patient education, joint protection training, dynamic orthotic positioning, and use of adaptive equipment must direct the rehabilitation program.
General Overview of Postoperative Therapy
The standard protocol following MCP joint arthroplasty involves immediate postoperative orthotic positioning with a dorsal extension outrigger fabricated at the first visit, which should be scheduled no later than 1 week after the surgery date. Therapy consists of AROM and gentle passive range of motion (PROM) of the reconstructed MCP joints, with care to control alignment, care of the incision, and skin inspection. Edema control and ADL training using joint protection principles are included. A home program of AROM within the orthosis and elevation to control edema is critical. Variations to the program are made based on problems identified throughout the postoperative course of therapy ( Table 107-1 ). Because of the nature and chronicity of RA, ROM exercises are emphasized for the neck, shoulders, elbows, wrists, hips, and knees. Specific details for postoperative therapy for MCP joint replacement are as follows.
| Problems Indentified in Therapy Program | Solutions and Interventions |
|---|---|
| Edema and postoperative pain |
|
| Fragile skin | Use silicone “second skin” padding under dorsal hand portion of outrigger. |
| Lack of MCP joint flexion at 3 weeks |
|
| Lack of MCP joint extension | Increase time in the dynamic-extension outrigger; limit flexion activities, particularly of the index and long fingers. |
| Rotation of index finger | Use supination outrigger on dynamic-extension orthosis. |
| Difficulty with applying orthosis straps because of weak pinch from arthritis and uninvolved hand | Use larger straps, all ulnar to radial direction, and D-ring sewn on strap for ease and loss of pinch strength. |
| Tendency for ulnar deviation | Use functional ulnar deviation orthosis. |
| Orthosis slippage (rotates on the forearm) | Use neoprene strap around wrist to anchor orthosis in place. |
| Lack of extension | Position at night with MCP joints supported in extension; duration of use varies up to 6 months to 1 year; wear daytime functional orthosis with support and protection of MCP joint to protect against lateral stresses and support in extension. |
Postoperative Therapy Goals
General therapy goals following MCP joint implant arthroplasty include the following:
- 1
Optimal wound healing
- 2
Prevention of scar adherence
- 3
Control of postoperative swelling
- 4
Neutral alignment and the desired degree of ROM at the reconstructed MCP joints
- 5
Optimal performance of ADLs and vocational/avocational pursuits
- 6
AROM of the shoulder, elbow, and remaining nonoperative joints
3 to 5 Days to 2 Weeks
The bulky dressing is removed, and a light compressive dressing is applied. The dressing is changed at each office visit until suture removal at 10 to 14 days postoperatively. At the initial therapy visit, a dynamic extension assist orthosis with control for MCP joint alignment is fabricated. This orthosis should not only extend, but also radially deviate the fingers. AROM and light PROM exercises for MCP joint flexion and extension are begun within the orthosis, with careful monitoring to ensure control of alignment and rotation. Edema control techniques such as compression bandages and Coban for finger edema are implemented at this time. Care must be taken to avoid traction on the skin in an ulnar direction by the compression bandages. A static orthosis with MCP joints supported in neutral or radial alignment also may be fabricated for night use.
Orthosis Specifications
Dynamic orthotic positioning is an important component of postoperative management. The purpose of the dynamic orthosis is to control the position and alignment of the reconstructed MCP joints and at the same time to allow guided ROM. In supporting the fingers in a neutral position (MCP joints at 0 degrees) while allowing movement of the reconstructed joint, the orthosis helps influence the encapsulation process and maintain capsular length throughout the period of scar remodeling. The orthosis also is necessary to guide the motion of the joint in flexion and extension and prevent recurrence of the ulnar deviation deformity.
The dynamic orthosis may be worn during the day and a static forearm-based wrist orthosis with MCP support in neutral at night, depending on individual considerations. A static night orthosis ( Fig. 107-10 ) should have either an ulnar border with a trough or Velcro straps (Velcro USA, Manchester, New Hampshire) to prevent ulnar drift. The radial surface of the orthosis can be flat. The dynamic orthosis ( Fig. 107-11A–C ) is based dorsally with an extension outrigger. Finger slings with elastic traction, which attach to the outrigger, support the MCP joints in extension while avoiding hyperextension. They are placed at the proximal end of the proximal phalanges to guide motion and alignment of the digits. A 90-degree angle of pull from the proximal phalanx to the outrigger, maintaining the reconstructed MCP joints in a neutral position of extension when at rest, must be achieved. In addition, the pull should be in a radial direction to prevent recurrence of ulnar drift and also to prevent lateral and medial instability by decreasing stress on the lateral capsular structure. The traction device (rubber bands or springs) should be relaxed enough to allow for approximately 70 degrees of active MCP joint flexion. DeVore recommends no. 10 size rubber bands to create the appropriate tension. The force magnitude must be kept low enough to prevent pain and swelling.
