Pyrocarbon interposition arthroplasty Info 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. We usually recommend non-operative care first. This includes activity changes, hand therapy, splinting, and injections. We consider surgery when these measures do not give enough improvement.
Your surgeon may suggest pyrocarbon interposition arthroplasty if you have early wear-and-tear arthritis in your thumb base. This procedure places a small spacer to cushion the joint. It is often chosen when removing the bone entirely seems too destructive, or when a full joint replacement seems unnecessary. The goal is to relieve pain and improve movement while keeping your thumb length and pinch strength. Studies show good implant survival for at least 8 years.
Before the operation
You must fast before your surgery. Your surgeon will tell you exactly when to stop eating and drinking. Please arrange for someone to drive you home after the procedure. Wear comfortable, loose clothing on the day of your operation. Bring a complete list of all medications you currently take. You may need an anaesthetic review to check your fitness for surgery. X-rays or blood tests might also be required beforehand. These steps help your surgeon plan your care safely. We want to ensure you are fully prepared for a smooth start to your recovery journey.
On the day
You present to the hospital's surgical admissions unit, where you are checked in and prepared for theatre. You meet the anaesthetist to discuss your care. 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 wake up in the recovery area, where nurses monitor you while the anaesthetic wears off. Once you are stable you either go to the ward or go home, depending on the procedure and your recovery.
What the operation involves
Your surgeon makes a single cut over the base of your thumb to access the joint. This is an open approach, meaning the area is clearly visible rather than viewed through small cameras. Through this opening, your surgeon carefully removes part of the trapezium bone, which is the small bone at the base of your thumb that has become worn out.
Next, a flexible pyrocarbon spacer is placed into the space where the bone was removed. This implant acts like a cushion between your thumb and wrist bones. It helps to maintain the length of your thumb and keeps the joint stable. By replacing the worn surfaces with this smooth material, your surgeon aims to reduce friction and allow for smoother movement.
The cut is then closed with stitches, and a dressing is applied to protect the area. This procedure is designed to improve your ability to move your thumb actively and passively. It also helps to preserve your key pinch strength, which is essential for holding objects firmly. The goal is to provide pain relief while keeping your thumb functional for daily tasks.
After the operation
You will wake up in the recovery ward with your hand in a sling and a protective splint. Most patients stay one night in hospital after this operation, though some are able to go home the same day. We will manage your pain with standard medication. Keep the dressing clean and dry. You must have someone stay with you for the first 24 hours. Do not drive while wearing the thumb spica splint, as it stops you from gripping the wheel safely. You can only drive once the splint is removed and your surgeon clears you. See our guide on Driving after upper-limb surgery.
Recovery
You can expect some pain and swelling in the days and weeks after your procedure. This is a normal part of healing. We manage this discomfort with medication and by keeping your hand elevated above your heart as much as possible. Your surgeon will guide you on what is safe for your specific case.
You will wear a thumb spica splint for four to six weeks. This splint protects the joint while it heals. You cannot drive while wearing this splint because it stops you from gripping the steering wheel safely. You can return to driving once the splint is removed and your surgeon clears you. For more details, see Driving after upper-limb surgery.
Rehabilitation is a key part of your recovery. Hand therapy after surgery is with Ruby Doolan at Extend Rehabilitation. Your therapist will teach you gentle exercises to restore movement and strength. You will start with simple tasks at home, like holding a cup, before moving to stronger grips.
As your swelling settles and movement returns, you will gradually resume daily activities. You might notice improved pinch strength as you get stronger. Your timeline may differ; your surgeon and hand therapist will guide you based on how your body responds.
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.
This procedure may not be suitable for you if you have wear-and-tear arthritis in the small joints next to your thumb base. This is especially true if you plan to keep playing high-impact sports like tennis. These activities put heavy pressure on your wrist while it is bent back. If you continue these actions, the implant may not last or could cause pain. You might notice increased discomfort in your wrist during or after these movements. If you have these plans, please discuss them with us before surgery so we can decide if this operation is right for you.
The complications table on this page lists typical rates if you want the specifics.
When to call us
Call us if you have fever, increasing wound redness or discharge, or sudden severe pain. Go to emergency if you notice calf swelling, shortness of breath, loss of sensation, or inability to move your limb. These signs need urgent assessment. We want to ensure your recovery stays on track. Please do not wait if you feel something is wrong. Contact our team immediately for guidance.
Where to read more
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.
Where to read more
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.
