Pyrocarbon interposition arthroplasty Info Evidence Consent
Reviewed by Dr Kieran Hirpara, Specialist Orthopaedic Surgeon Last reviewed
Why this operation has been suggested
Dr Kieran Hirpara, an upper-limb surgeon at Mater Private Hospital Rockhampton, starts with the least invasive options that suit your condition. Patients are generally referred to our clinic by their GP; if a physiotherapist has suggested you see us, you will still need a referral from your GP in order to be eligible for the Medicare rebate. At your appointment we take a history, examine your hand and arrange imaging where needed to work out what is causing your pain. For long-standing wear-and-tear arthritis we usually try non-operative care first, such as activity change, hand therapy or splinting. We consider surgery when those steps have not given you enough improvement.
This operation replaces the worn joint surface with a smooth, durable implant that acts as a spacer inside the joint. It is typically offered to people with painful thumb or finger arthritis that has not settled with non-operative care. It suits some people whose arthritis is early, where removing the whole joint would be more destructive than needed. It also suits younger, active patients who want to keep joint height and movement. The operation aims to relieve pain while keeping your thumb or finger working and stable.
Before the operation
Once surgery is booked, we will give you clear instructions to follow in the days before you come in. You will need to stop eating and drinking for seven hours beforehand. We ask for seven hours rather than six so that your operation can be brought forward if the theatre list runs early. You will also need to stop taking some medications before surgery, and we will tell you exactly which ones and when. Bring a written list of everything you take, arrange for someone to drive you home, and wear loose, comfortable clothing. We will already have imaging such as X-rays, and sometimes an MRI or ultrasound, to plan the operation. If you have other medical conditions, you may need blood tests or a review with the anaesthetist.
On the day
You will come to the hospital's surgical admissions unit, where you are checked in and prepared for theatre. You will meet the anaesthetist before your operation. This operation is done under general anaesthetic. You will be fully asleep for the operation. Some patients may also have a regional nerve block for post-operative pain relief; the anaesthetist decides on the day based on your individual circumstances. You are then taken into the operating theatre, where the operation is performed.
You will wake up in the recovery area, where nurses watch over you while the anaesthetic wears off. Once you are stable, you will either go to the ward or go home, depending on the procedure and how you recover.
What the operation involves
Your surgeon makes a single cut over the joint being operated on. Through this opening, they remove the worn, rough joint surfaces that have been causing your pain. A smooth pyrocarbon implant is then placed in the joint. Pyrocarbon is a durable, low-friction material that acts as a spacer between the bones, so the joint can glide again instead of grinding.
Depending on your joint, your surgeon may replace one or both sides of the joint. Sometimes only the bone on one side is resurfaced and the implant fills the space left after the worn surface is cleared away. The implant is shaped to match the natural contour of your own joint so it sits securely and moves the way your joint was designed to move.
Once the implant is in place, your surgeon checks that the finger or thumb lines up correctly and moves smoothly. The wound is then closed with stitches, and a dressing is applied over the top.
The aim of all of this is simple: to give your joint a smooth new surface so that the bones no longer rub on raw, arthritic bone. You will go home with the dressing in place, and your surgeon will explain what happens next.
After the operation
Most patients stay one night in hospital after this operation, though some are able to go home the same day. You will wake up in the recovery area, then move to the ward when you are steady. Nurses will check on you and give you pain relief as you need it. Your hand will be in a dressing and a splint to rest the joint while it settles. Keep your hand raised on a pillow when sitting or lying down; this helps with swelling. We leave the dressing on for about 10 days; please do not take it off before then unless we tell you to. We change or remove it when we see you. Please arrange for someone to stay with you for the first 24 hours after you get home.
Recovery
For the first few days your hand will be sore and swollen, and this is normal. Keeping your hand raised on a pillow eases the swelling, and the pain relief you are given helps with the discomfort. The soreness settles gradually as the joint calms down.
You will leave hospital with your hand in a dressing and a splint that rests the joint while it heals. We leave the dressing on for about 10 days and change it when we see you. Rehabilitation after hand surgery is hand therapy, not physiotherapy: your appointments are with Ruby Doolan at Extend Rehabilitation. Ruby directs your therapy and makes any splint you need along the way. She will show you gentle exercises that keep your fingers moving and stop stiffness setting in, and she will guide you as movement returns.
At home, you can do most everyday things with your other hand while the operated one settles. You will not drive while the splint is on, because it stops you gripping the wheel safely. Once the splint is removed and your surgeon clears you, driving can resume; see our page on Driving after upper-limb surgery. Heavy lifting comes back last, once your therapist is happy with how the joint is bearing load.
As the weeks pass, the swelling goes down, your grip strengthens and the joint glides more freely. Many people notice the pain has eased well before full strength returns. Recovery varies from person to person, so your timeline may differ; your surgeon and hand therapist will guide you at each visit.
What can go wrong
Most patients do well, but problems can occasionally happen. Your surgeon and the team monitor you closely to spot any issue early.
The implant can loosen over time. You might notice a deep, throbbing pain in the joint that does not ease with simple painkillers, or a new clicking or grinding feeling when you move. Tell your surgeon at your next review if this happens.
The implant can also settle or sink into the bone, sometimes with weakness or the return of pain. The joint may change shape or become unstable, so the finger or thumb feels like it is shifting or giving way. Bring this up at your review appointment.
Stiffness can develop in the joint, and pain can persist. If the joint will not bend or straighten as far as you expected, or pain stays severe, your surgeon will assess what is causing it.
Sometimes the bone around the implant changes. This usually causes no symptoms and is often picked up on X-rays at your routine reviews, so keep attending them even when the hand feels fine.
If a joint replacement does not work out, there are reliable ways to deal with it. For a finger joint, the failed implant can be removed and the bones on either side joined together so the finger fuses in a useful position. This is usually done with a metal pin, sometimes with a small bone graft to keep the finger at a handy length. The hand can take a while to settle afterwards, and the finger will be stiffer than before, but the pain is usually gone.
For a thumb joint, a failed implant can be treated by removing it and taking out the small bone next to it. This is an established operation in its own right and reliably eases the pain that the failed implant caused.
If you notice spreading redness, warmth or increasing pain around the wound, contact the clinic promptly. The complications table on this page lists typical rates if you want the specifics.
When to call us
Most problems after this operation are picked up early, so it pays to know what to watch for. Call us if you have a fever, if the skin around the wound becomes more red or starts discharging fluid, or if the pain suddenly becomes severe. Go to emergency if you have swelling or pain in your calf, or shortness of breath, because these can be signs of a blood clot. Call us straight away if your hand or fingers go numb, feel cold, or change colour, or if you cannot move them at all. If in doubt, call us; we would rather hear about a small worry than miss a big one.
Where to read more about the condition
This page is about the operation itself. The condition it treats, including what the evidence shows about when surgery helps and when it does not, is covered in more detail on the Basal Thumb Arthritis page.
Evidence & references
This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.
Overview
- Pyrocarbon interposition arthroplasty is considered a viable option for patients with early trapeziometacarpal osteoarthritis who are unresponsive to conservative measures, where trapeziectomy may be considered too destructive and hemi or total arthroplasty overzealous [1].
- Pyrocarbon interpositional arthroplasty provides pain relief and high patient satisfaction with good implant longevity [2].
- Partial trapeziectomy with pyrocarbon arthroplasty provides excellent pain relief and high patient satisfaction for the treatment of trapeziometacarpal joint osteoarthritis [3].
- The PyroDisk implant for treating advanced trapeziometacarpal arthritis did not demonstrate superiority over published outcome data of trapeziectomy with or without ligament reconstruction and tendon interposition [4].
- The modified procedure of partial trapeziectomy and pyrocarbon interpositional arthroplasty increases active and passive range of movement at the trapeziometacarpal joint [5].
- The modified procedure of partial trapeziectomy and pyrocarbon interpositional arthroplasty provides joint stability comparable to standard techniques [5].
- The modified procedure of partial trapeziectomy and pyrocarbon interpositional arthroplasty provides pain relief comparable to standard techniques [5].
- The modified procedure of partial trapeziectomy and pyrocarbon interpositional arthroplasty preserves thumb length [5].
- The modified procedure of partial trapeziectomy and pyrocarbon interpositional arthroplasty preserves key pinch strength [5].
- Long-term follow-up data for pyrocarbon disc interposition for the treatment of CMC1 osteoarthritis grade 2 to 3 in more than 150 thumbs has been reported [6].
- Subjective and objective outcomes were similar following ligament reconstruction and tendon interposition and pyrolytic interpositional arthroplasty in patients with trapeziometacarpal arthritis [7].
- Pinch strength was more improved following pyrolytic interpositional arthroplasty compared to ligament reconstruction and tendon interposition [7].
- The Pyrocardan implant may be contraindicated in patients with symptomatic scaphotrapeziotrapezoid osteoarthritis who intend to continue high-load activities involving wrist extension under load, such as tennis [8].
Anatomy & Pathophysiology
TMC Joint Biomechanics and Function
- The thumb metacarpal is independent and articulates with the trapezium [15].
- The thumb ray is the most divergent of the five rays of the hand [15].
- The thumb has a more proximal and lateral position, allowing movement inward and outward from the palm [10].
- The thumb is the master digit of the hand and represents the dominant element which gives value to all other digits [15].
- The web space of the thumb is the largest and deepest web space in the hand [10].
- The distal transverse ligament at the level of the thumb web is by far the deepest and most mobile commissural skeleton structure [11].
Surgical Anatomy and Vascularization
- The most important structure in the thenar area is the recurrent branch (motor) of the median nerve [17].
- Anatomic studies show that there is no single longitudinal incision in the proximal palm that completely avoids the palmar cutaneous branches of the median and ulnar nerves [17].
- The "princeps pollicis" artery is the terminal branch of the radial artery that crosses the first intermetacarpal space [16].
- The "princeps pollicis" artery runs along the ulnar side of the first metacarpal bone and along the volar surface of the adductor muscle [16].
- The "princeps pollicis" artery emerges onto the subcutaneous palmar tissue at the level of the cutaneous flexion crease of the metacarpophalangeal joint [16].
- At the metacarpophalangeal joint crease, the "princeps pollicis" artery divides into two terminal rami known as the collateral palmar arteries of the thumb [16].
- Only 15% of anatomical dissections of the palmar arteries of the thumb fall into the classical layout category [16].
- The ulnar collateral artery is the main artery in the second segment of the thumb and is more often easier to dissect than the radial collateral artery [16].
- A subtendinous anastomosis situated at the level of the neck of the first phalanx acts as a moderator between the two collateral arteries [16].
- The dorsal arteries of the thumb originate from palmar arteries (princeps, commissural, or anastomoses of the superficial arcade) at the level of the first metacarpal [16].
- The ulnar dorso-collateral artery generally stems from the "princeps pollicis" onto the medial border of the neck of the first metacarpal [16].
Clinical Evaluation
- A careful physical examination is essential to direct care and future testing if indicated [9].
- Patients often have difficulty accurately describing their symptoms and may incorrectly attribute pathology to a perceived deficit [9].
- Diagnostic tests such as imaging and serum laboratory studies can be expensive, time consuming, and often nonspecific [9].
Classification
- Pyrocarbon interposition arthroplasty is considered a treatment option for patients with early trapeziometacarpal osteoarthritis who are unresponsive to conservative measures [1].
- Pyrocarbon interposition arthroplasty is considered for patients in whom trapeziectomy may be considered too destructive and hemi or total arthroplasty overzealous [1].
- Pyrocarbon interpositional arthroplasty is indicated for the treatment of trapeziometacarpal joint osteoarthritis [3].
- The PyroDisk implant is used for the treatment of advanced trapeziometacarpal arthritis [4].
- Pyrocarbon disc interposition is used for the treatment of CMC1 osteoarthritis grade 2 to 3 [6].
- The Pyrocardan implant may be contraindicated in patients with symptomatic STT OA who intend to continue high-load activities, particularly those involving wrist extension under load, such as tennis [8].
Clinical Presentation
- Pyrocarbon interposition arthroplasty is considered for patients with early trapeziometacarpal osteoarthritis who are unresponsive to conservative measures [1].
- Pyrocarbon interposition arthroplasty is considered for patients in whom trapeziectomy may be considered too destructive [1].
- Pyrocarbon interposition arthroplasty is considered for patients in whom hemi or total arthroplasty may be considered overzealous [1].
- Pyrocarbon interposition arthroplasty is indicated for the treatment of trapeziometacarpal joint osteoarthritis [3].
- Pyrocarbon interposition arthroplasty is indicated for the treatment of advanced trapeziometacarpal arthritis [4].
- Pyrocarbon disc interposition is indicated for the treatment of CMC1 osteoarthritis grade 2 to 3 [6].
- The Pyrocardan implant may be contraindicated in patients with symptomatic STT osteoarthritis who intend to continue high-load activities [8].
- The Pyrocardan implant may be contraindicated in patients with symptomatic STT osteoarthritis who intend to continue activities involving wrist extension under load, such as tennis [8].
Investigations
- Clinical evaluation of the hand and wrist requires combining patient history with a careful physical examination to pinpoint or narrow the scope of possible pathologic processes [9].
- Diagnostic tests such as imaging and serum laboratory studies are useful in determining pathology but can be expensive, time consuming, and often nonspecific [9].
- The trapezium is clearly angled out in front of the carpal plane so that the first metacarpal makes an angle of about 45 degrees with the second metacarpal in the sagittal plane [20].
- The articular surfaces of the trapezium and the base of the first metacarpal have a saddle shape in opposing planes [20].
Treatment
- PyroDisk interposition has merit in patients with early trapeziometacarpal osteoarthritis unresponsive to conservative measures, in whom trapeziectomy may be considered too destructive and hemi or total arthroplasty overzealous [1].
- Pyrocarbon interpositional arthroplasty provided pain relief and high patient satisfaction with good implant longevity [2].
- Long-term follow-up data for pyrocarbon disc interposition for the treatment of CMC1 osteoarthritis grade 2 to 3 is available in more than 150 thumbs [6].
- Subjective outcomes were similar following ligament reconstruction and tendon interposition and pyrolytic interpositional arthroplasty in patients with trapeziometacarpal arthritis [7].
- Objective outcomes were similar following ligament reconstruction and tendon interposition and pyrolytic interpositional arthroplasty in patients with trapeziometacarpal arthritis, except for pinch strength [7].
- Pinch strength was more improved following pyrolytic interpositional arthroplasty than ligament reconstruction and tendon interposition [7].
- The Pyrocardan implant may be contraindicated in patients with symptomatic scaphotrapeziotrapezoid osteoarthritis who intend to continue high-load activities, particularly those involving wrist extension under load, such as tennis [8].
Recovery
- Partial trapeziectomy with pyrocarbon arthroplasty provides excellent pain relief and high patient satisfaction [3].
- The modified procedure improves functional results by increasing active and passive range of movement at the trapeziometacarpal joint [5].
- The modified procedure provides joint stability and pain relief comparable to standard techniques [5].
- The modified procedure preserves thumb length and key pinch strength [5].
- All subjective and objective outcomes were similar following ligament reconstruction and tendon interposition and pyrolytic interpositional arthroplasty, except for pinch strength [7].
Key Evidence
- [L4] PyroDisk interposition has merit in patients with early disease unresponsive to conservative measures, in whom trapeziectomy may be considered too destructive and hemi or total arthroplasty overzealous. [1] (10.1177/1753193420981552)
- [L4] Pyrocarbon interpositional arthroplasty provided pain relief and high patient satisfaction with good implant longevity. [2] (10.1177/1753193420906805)
- [L3] Partial trapeziectomy with pyrocarbon arthroplasty may prove to be a successful option for the treatment of trapeziometacarpal joint osteoarthritis, providing excellent pain relief and high patient satisfaction. [3] (10.1177/1753193413519384)
- [L4] The PyroDisk implant for treating advanced trapeziometacarpal arthritis did not demonstrate superiority over published outcome data of trapeziectomy with or without ligament reconstruction and tendon interposition. [4] (10.1016/j.jhsa.2014.07.011)
- [L4] The modified procedure improves functional results by increasing active and passive range of movement at the TMCJ, providing joint stability and pain relief comparable to standard techniques, while preserving thumb length and key pinch strength. [5] (10.1177/1753193414553368)
- [L4] This is the first study with long-term follow-up after pyrocarbon disc interposition for the treatment of CMC1 osteoarthritis grade 2 to 3 in more than 150 thumbs. [6] (10.1016/j.jhsa.2018.06.086)
- [L3] All subjective and objective outcomes were similar following LRTI and pyrolytic interpositional arthroplasty in patients with TMC arthritis, except pinch strength, which was more improved following pyrolytic interpositional arthroplasty. [7] (10.1155/2019/7961507)
- [Case_report] The Pyrocardan implant may be contraindicated in patients with symptomatic STT OA who intend to continue high-load activities, particularly those involving wrist extension under load, such as tennis. [8] (10.1016/j.jhsg.2026.100964)
References
[1] Re: Smeraglia F, et al. Partial trapeziectomy and pyrocarbon interpositional arthroplasty for trapeziometacarpal osteoarthritis: minimum 8-year follow-up. J Hand Surg Eur. 2020, 45: 472–6. Journal of Hand Surgery (European Volume). 2021. DOI: 10.1177/1753193420981552
[2] Partial trapeziectomy and pyrocarbon interpositional arthroplasty for trapeziometacarpal osteoarthritis: minimum 8-year follow-up. Journal of Hand Surgery (European Volume). 2020. DOI: 10.1177/1753193420906805
[3] Partial trapeziectomy and pyrocarbon interpositional arthroplasty for trapeziometacarpal joint osteoarthritis: results after minimum 2 years of follow-up. Journal of Hand Surgery (European Volume). 2014. DOI: 10.1177/1753193413519384
[4] Pyrocarbon Interposition (PyroDisk) Implant for Trapeziometacarpal Osteoarthritis: Minimum 5-Year Follow-Up. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.07.011
[5] Re: Mariconda et al. Partial trapeziectomy and pyrocarbon interpositional arthroplasty for trapeziometacarpal joint osteoarthritis: results after minimum 2 years of follow-up. J Hand Surg Eur. 2014, 39: 604–610. Journal of Hand Surgery (European Volume). 2014. DOI: 10.1177/1753193414553368
[6] Long-Term Follow-Up After Pyrocarbon Disc Interposition for Thumb CMC Osteoarthritis. The Journal of Hand Surgery. 2018. DOI: 10.1016/j.jhsa.2018.06.086
[7] Tendon versus Pyrocarbon Interpositional Arthroplasty in the Treatment of Trapeziometacarpal Osteoarthritis. BioMed Research International. 2019. DOI: 10.1155/2019/7961507
[8] Game, Set… Revision! A Case Report of a Tennis Player Who Smashed His Scaphotrapeziotrapezoid-Joint Pyrocardan Implant Twice. Journal of Hand Surgery Global Online. 2026. DOI: 10.1016/j.jhsg.2026.100964
[9] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Anatomy, Evaluation, Clinical Examination, and Imaging > Evaluation and Clinical Examination: Current Concepts.
[10] Exam Of The Hand Wrist 2Ed. INTRODUCTION.
[11] Exam Of The Hand Wrist 2Ed. Functional cutaneous units.
[15] Exam Of The Hand Wrist 2Ed. The arches of the hand > The metacarpal arch.
[16] Exam Of The Hand Wrist 2Ed. Techniques of investigation of the arterial supply by J P Melki > Vascularization of the thumb > Palmar aspect.
[17] Campbell S Operative Orthopaedics 4 Volume Set. RESULTS OF SUTURE OF THE SCIATIC NERVE > PALMAR INCISIONS.
[20] Exam Of The Hand Wrist 2Ed. 1.1 SKELETON OF THE HAND > The osseous skeleton.
