Thumb CMC Osteoarthritis: LRTI Procedure, Simple Trapeziectomy, CMC Arthrodesis

Jennifer Moriatis Wolf, MD

Katherine Barnum Baynes, MS, OTR, CHT

Ms. Barnum or an immediate family member is an employee of Falcon Rehab Products. Dr. Wolf or an immediate family member has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research–related funding (such as paid travel) from Elsevier, the Journal of Hand Surgery; and serves as a board member, owner, officer, or committee member of the American Society for Surgery of the Hand, the Journal of Bone and Joint Surgery–American, the Journal of Hand Surgery–American, and Orthopedics.

Introduction

Trapeziometacarpal (TM) osteoarthritis is common, appearing most frequently in middle-aged women and increasing in prevalence with age. This degenerative condition is thought to be due to attenuation of the stabilizing ligaments of the thumb base, as well as to chronically stressing this saddle-shaped joint during use of the thumb. After failing nonoperative treatments, including opponens splinting and corticosteroid injections, there are several surgical treatment options.

Ligament reconstruction and tendon interposition (LRTI), as described by Eaton and Littler and modified by Burton and Pellegrini, remains the most commonly performed surgical procedure. The trapezium is removed and half or all of the flexor carpi radialis (FCR) tendon is used to reconstruct the stabilizing ligaments and form an “anchovy” to cushion the base of the first metacarpal. Simple trapeziectomy is similar, but does not require tendon transfer or specifically reconstruct the ligaments. Finally, TM arthrodesis, with fusion of the trapezium to the first metacarpal, is typically chosen in young laborers and is performed using fixation with wires or plate/screw constructs.

All of these procedures typically require an initial period of immobilization which contributes to stiffness in the tissues around the TM joint. Postoperative rehabilitation is a key adjunct for these procedures, necessary for recovery from the surgical dissection and the subsequent immobilization. The goals of hand therapy after TM surgery reflect a graded return to activities, including increased range of motion (ROM), restoration of functional pinch and grasp, and strengthening.

Surgical Procedures

Ligament Reconstruction and Tendon Interposition and Simple Trapeziectomy

The indications for both LRTI and simple trapeziectomy are similar. These procedures are typically performed in patients with moderate to advanced-stage TM osteoarthritis who have failed nonoperative treatment such as activity modification, opponens splinting, and corticosteroid injections.

Collagen vascular diseases, with excessive joint laxity, are a contraindication for simple trapeziectomy, as these patients may require ligament reconstruction to avoid instability.

Procedure

The two most common surgical approaches are the volarly based Wagner approach (Figure 26.1), which exposes and peels up the thenar musculature to expose the joint capsule, and the longitudinal dorsal approach between the abductor pollicis longus and extensor pollicis longus (Figure 26.2), exposing the anatomic snuffbox. Recognition and protection of the deep branch of the radial artery at the proximal portion of the snuffbox and the branches of the superficial radial nerve are important. In LRTI, a separate forearm incision or incisions are placed to harvest either half or all of the FCR tendon.

In both approaches, the trapezium is removed either piecemeal or whole. If the FCR tendon is used, a drill hole is placed from the dorsal radial side of the first metacarpal obliquely into its base, and the tendon is passed through the base and sutured to itself to suspend the metacarpal, with the remaining tendon fashioned into an “anchovy” spacer and placed into the joint. The capsule is then closed with resorbable suture. The subcutaneous tissues are approximated with resorbable sutures and the skin closed with a running subcuticular suture.

The thumb is immobilized in a bulky dressing and thumb spica splint holding the thumb in a functional opposition position immediately postoperatively, then is changed into a short-arm thumb spica cast, which is maintained for 4 additional weeks for a total of 6 weeks of immobilization.

Potential surgical complications that may impact rehabilitation include damage to the superficial radial nerve branches with neuroma formation and incisional pain, or FCR tendinitis when half the tendon is harvested.

Figure 26.1 Illustration of volar Wagner approach to the thumb carpometacarpal joint, with the thenar musculature retracted ulnarly to expose the volar capsule, which is opened longitudinally over the trapezium. (Reproduced with permission from Wiesel S, ed: Operative Techniques in Orthopaedic Surgery. Philadelphia, PA, Lippincott Williams & Wilkins, 2010.)

Trapeziometacarpal Arthrodesis

TM arthrodesis in indicated in the young laborer or other worker who needs a stable joint to tolerate heavy loads. Previous arthrodesis of the thumb metacarpophalangeal (MCP) joint is a contraindication to TM fusion, as more proximal arthrodesis would severely limit any thumb mobility. Relative contraindications include patients with occupations requiring a high degree of thumb mobility, such as musicians, dentists, and graphic designers.

Fusion of the TM joint is typically performed using the dorsal approach described earlier. The TM joint is exposed and decorticated. The joint is positioned to allow the distal phalanx of the thumb to contact the middle phalanx of the index finger, with the thumb rotated into sufficient opposition to allow
circumduction across the palm. The joint is then stabilized with Kirschner wires (K-wires), staples, screws, or plates placed on the dorsal surface of the thumb metacarpal and trapezium. The periosteum is then closed over the construct chosen, followed by closure of the tendon interval and skin. As described earlier, the patient is placed into a bulky dressing and thumb spica splint, which is then converted to a thumb spica cast at 10 to 14 days.

Figure 26.2 Illustration of dorsal approach to the thumb carpometacarpal joint. A and B, The interval between the abductor pollicis longus and extensor pollicis longus is opened, exposing the dorsal capsule. This is opened, with careful protection of the radial artery at the base of the anatomic snuffbox. (Reproduced with permission from Cooney WP: The Wrist: Diagnosis and Operative Treatment, ed 2. Philadelphia, PA: Lippincott Williams & Wilkins, 2010.)

Trapeziometacarpal Implant Arthroplasty

Multiple implant options have been described for use in the TM joint, including silicone, metal-polyethylene, and pyrocarbon constructs, with either stemmed (placed into the first metacarpal base) or spacer options. The surgical approach is either through a dorsal or volar Wagner interval, per the surgeon’s preference. After removal of the joint surfaces and implant placement, it is critical to repair the capsular interval securely, as dislocation of TM implants is a well-described complication. The patient is typically immobilized in a thumb spica splint for 2 to 3 weeks at a minimum before mobilization is allowed, and a removable thumb spica splint is used to support the joint while the soft tissues heal to provide implant stability.

Postoperative Rehabilitation Following Trapeziometacarpal Joint Procedures

Postoperative rehabilitative care of the patient should begin early after surgery in ensure the best possible outcome, recognizing the balance between immobilization for stability and healing and motion to maintain function. Early interventions include adequate postoperative immobilization with functional positioning of the thumb, edema management, and ROM beginning at the initial postoperative visit. Patients who undergo TM joint procedures often have adjacent joints affected by osteoarthritis, or pain and symptoms in the contralateral hand and thumb that may be exacerbated by increased use and stress as the patient becomes predominantly dependent on the nonoperative hand during the postoperative immobilization period. The ultimate goal of the rehabilitation process is to assist the patient in a customized program that allows the patient to return to the activities that were previously limited by a painful, unstable thumb. An older patient who performs basic homemaking tasks will require a different postoperative program than a person whose hands have greater physical demands. Recovery time from surgery typically is between 3 and 6 months depending on the patient’s level of hand function.

Unless surgically corrected, altered preoperative prehension patterns will likely reappear postoperatively. Encourage the patient to adopt balanced thumb postures to reduce the stress on the postoperative site, which allows the appropriate musculature to perform the task. Patients who had been primarily using the adductor pollicis muscle to perform prehension tasks due to joint collapse need to be retrained through instruction in prehension patterns and in strengthening of the opponens pollicis, abductor pollicis brevis, and first dorsal interosseous muscles. Encouraging balanced prehension patterns of thumb MCP flexion and interphalangeal (IP) flexion with dynamic stabilization of the thumb during light tasks, with progression to activities with loading, is part of a postoperative neuromuscular re-education program.

A staged and graded program is designed to provide the following:

Functional ROM for tasks
Functional strength for grip-and-pinch activities and patient-specific tasks
Neuromuscular re-education to encourage balanced pinch postures for tasks with loaded pinch for long-term protection of the procedure
Joint protection education

Postoperative Rehabilitation for LRTI and Simple Trapeziectomy Procedures—Authors’ Preferred Protocol

Postoperative Immobilization

Casting (weeks 0–4)
- Initial postoperative dressing is replaced with a thumb spica cast.
- Optimal thumb position is midway between radial and palmar abduction, while preserving the web space.
- MCP joint is placed in 30° of flexion and the IP joint is left free.
Splinting (weeks 4–8)
- Volar-based or circumferential forearm-based thumb spica splint (Figure 26.3) allows wrist and thumb active ROM and passive ROM exercises to begin.
- Wean out of the splint for light tasks between weeks 6 and 8.
- Transition may include progressing to a hand-based protective splint, as desired.
Hand-based splints (week 8 and beyond)
- Thermoplastic (Figure 26.4) or soft supports (Figure 26.5) that provide continued protection at the surgical site and splinting for positioning of the MCP and IP to encourage optimal positioning may be used as long as needed for comfort after surgery.