Exploring thumb joint replacement: A comprehensive overview

In his latest online article, Mr Ibrahim Roushdi gives us his insights into thumb joint replacement. He talks about the indications for a thumb joint replacement, the different types of implants, the risks and benefits, the recovery process and the alternatives to surgery.

What are the indications for thumb joint replacement?

The primary candidates for thumb joint replacement are individuals experiencing arthritis at the base of the thumb, seeking enhanced functionality beyond what traditional surgical interventions for thumb arthritis can offer. Before discussing thumb joint replacement, it's touching on the most common, traditional procedure for arthritis at the base, known as trapeziectomy.

In cases of arthritic joints, pain arises when the articular cartilage, the gristle covering the joint's end, wears away, leading to bone-on-bone friction. Traditionally, the solution involves removing the bone at the thumb's base, called the trapezium, allowing the gap to be filled with scar tissue. Tendon material may be employed to fill the space or support the thumb's base. While trapeziectomy is an effective and time-tested procedure providing significant pain relief, it entails the loss of some bony support. This can pose challenges, especially for patients seeking a higher level of functionality. This is where alternative options, such as joint replacement, become particularly relevant.

What are the different types of thumb joint replacement implants?

Over the years, various types of implants have been experimented with, including small silicone implants, plastic buttons, and materials like pyro carbon.

Difficulties with these have lead to the development of an implant closely resembling a miniature hip replacement. This implant features a small stem that extends into the metacarpal, a cup positioned within the bone known as the trapezium, and a ball-and-socket joint. This configuration currently stands out as the most promising and effective option available.

What are the risks and benefits of thumb joint replacement surgery?

In terms of advantages, thumb base replacements, when compared to the traditional gold standard, trapeziectomy (XME), offer swifter recovery, improved range of motion, enhanced thumb strength, better pain relief, and a more aesthetically normal appearance post-operation. However, like any medical intervention, there are trade-offs. The introduction of a joint replacement brings additional risks, including a heightened susceptibility to infections around the joint and potential fractures around the adjacent bones. While there is a theoretical risk of dislocation, newer-generation joint replacements have shown this to be less of a significant issue.

One primary trade-off with any joint replacement is its limited life expectancy; all replacements will eventually wear out or become loose. While established data suggest hip replacements can reliably last 20 years or more, the current generation of thumb base joint replacements lacks such long-term certainty. Traditionally, there were concerns about the cup coming loose, but with the latest generation in use for approximately seven years (with published data spanning up to nine years), the results have been promising. Over nine out of 10 replacements have demonstrated durability, as reflected in the available literature. However, the medium to long-term prognosis remains uncertain, and while there is optimism that they may endure as well as the best hip replacements, definitive conclusions are not yet available.

What is the recovery process like after thumb joint replacement surgery?

The recovery process following thumb base replacement surgery is notably more manageable compared to trapeziectomy, especially in the initial weeks. Patients typically return home with a large protective dressing to safeguard the wound and implant during the initial couple of weeks.

Around the two-week mark, the substantial dressing is removed, and we assess the wound's satisfactory healing. At this point, the majority of individuals can resume activities independently without requiring extensive physiotherapy. In cases where there is some discomfort, a splint might be utilised for a few weeks, primarily aimed at cautioning patients rather than necessitating intensive rehabilitation. We advise patients to exercise caution for the first six weeks post-surgery, gradually increasing activity from the sixth week onward. Heavy lifting or strenuous activities are to be avoided until 10 to 12 weeks post-surgery. However, within a couple of weeks, most individuals find themselves capable of tasks such as writing and typing, marking a swift return to regular activities.

What are the alternatives to this surgery?

The primary approach for managing arthritis involves steering clear of surgical interventions whenever possible. Initially, we encourage patients to consult with hand therapists, engage in exercises, and experiment with various splints and supports available in the market. Finding the most effective solution often involves a process of trial and error tailored to individual needs.

Steroid injections can be employed to alleviate symptoms temporarily. However, if the condition deteriorates to the point of requiring surgery, several options are available. One commonly discussed procedure is trapeziectomy, involving the removal of the bone at the thumb's base, considered a gold standard operation. Fusion, which entails permanently immobilising the joint, may be considered for individuals engaged in heavy manual labour. More specialised options exist, such as nerve division around the thumb's base to alleviate pain, but these have limited indications, and supporting data may not be as robust. In my practice, when surgery becomes necessary, approximately 99% of patients explore options like trapeziectomy or joint replacement. Increasingly, individuals are opting for the latter when it aligns with their specific needs.

Mr Ibrahim Roushdi is an esteemed consultant orthopaedic hand surgeon. You can schedule an appointment with Mr Roushdi on his Top Doctors profile.