Tendon transfer arthroplasty vs. LRTI arthroplasty for surgical treatment of basal joint arthritis of the thumb

Basal joint osteoarthritis (OA) of the thumb is a common, debilitating disease that can have a significant adverse effect on hand function. When conservative therapies, including NSAIDS, corticosteroid injection, splinting, and thenar muscle strengthening exercises, are ineffective, operative therapies such as simple trapeziectomy and trapeziectomy with interposition of tendon and/or muscle are generally pursued. All operative therapies are designed to preserve motion and prevent the complications of pain, instability, weakness, infection, and prolonged disability, which have been reported even after early post-operative success in some cases. To prevent these complications, careful selection of surgical candidates must be taken, along with attention paid to the specific procedural technique perfon-ned. Burton and Pellegrini developed and popularized the trapeziectomy with ligament reconstruction and tendon interpositon (LRTI) arthroplasty which was improved upon by Eaton and Littler in 1983. This technique is now the most commonly performed procedure for symptomatic treatment of the pain and instability that result from osteoarthritis at the basal joint of the thumb. However, the specific technique championed by Burton and Eaton involves the creation of a suspensionplasty, in which the base of the first metacarpal is tethered to the second metacarpal for stability and prevention of dorsal subluxation during normal hand function. This suspensionplasty entails creating an oblique hole through the dorsal cortex of the base of the metacarpal to allow a freed segment of the flexor carpi radialis (FCR) tendon to pass through the hole and be secured on the radial side of the metacarpal in an attempt to provide additionally stability to the tendon arthroplasty. This boring process, as well as the freeing of the segment of the FCR, are associated with an inherent risk of severe complications, such as superficial and recurrent motor branch of the median nerve, princeps pollicis artery injury and hemorrhage, tendon transection, and bony fragmentation of the metacarpal. Several variations of the LRTI procedure are currently in use, but there is no long-term literature supporting the use of such variations. One technique that has been performed since the early 1980's by Rosenwasser omits the boring phase of LRTI, thus completely preserving the structural integrity of the base of the first metacarpal and placing surrounding neurovascular structures at significantly less risk. Metacarpal stability is instead achieved through a simpler and less invasive tendon transfer step, involving the proximal segment of the abductor pollicus brevis (APB) released from the trapezium and transferred to the FCR tendon, I cm proximal to its insertion on the second metacarpal. The purpose of this study is to investigate the safety and effectiveness of the interposition arthroplasty and tendon transfer technique employed by Rosenwasser by comparing it to the current standard of care for operative technique. The study will compare the two techniques based on complication rates and the differences of pre-operative and post-operative functional outcome measures at a minimum of 3 years and a maximum of 20 years to hand function and symptoms prior to the procedure. Patients will be asked to complete a questionnaire, undergo radiograph evaluation, and be subject to a simple physical examination of the hands. The questionnaire will include outcome domains assessing changes in subjective pain, through a visual analog pain scales (VAS) as well as a commonly used, validated, functional outcome measure for the upper extremity, known as the Disabilities of the Arm, Shoulder and Hand (DASH) score. The radiographic evaluation will assess changes in the average subluxation of the base of the first metacarpal upon pinch grasp and average loss of scaphometacarpal space at rest. The physical exam will assess changes in joint range of motion, grip strength, and pinch strength. This study is of significant clinical value because the long-term follow-up of this procedure has