Wrist pain that comes back, months or years after a fall you had all but forgotten. Or an incidental finding on an X-ray taken for something else. The word "nonunion" is spoken, and it is as worrying as it is unfamiliar.
This article explains what this failure to heal is, why it should not be left alone even when it hurts little, and what surgery can truly do about it depending on how early it is caught.
What is a nonunion?
When a bone breaks, its two fragments normally knit back together within a few weeks: this is healing. We speak of nonunion when this bonding fails to happen and the fragments stay mobile relative to one another, forming a kind of false joint — which is the literal meaning of the word.
The scaphoid is especially prone to this complication, for two reasons already described in connection with its fracture: its blood supply runs in reverse, which readily starves the upper fragment of blood, and its fracture often goes unnoticed at first, so it is not immobilized in time. See the scaphoid fracture article.
Scaphoid fractures heal in the great majority of cases, but a portion of them — on the order of 10 to 15% depending on the series — progress to nonunion, particularly when the fracture was displaced, high on the bone, or treated late. 2025 meta-analysis
Why it should not be left alone
This is the heart of the matter, and the most counterintuitive point: a nonunion can be nearly symptom-free, with minimal intermittent pain for years, all while progressively damaging the wrist.
When the scaphoid is no longer a solid unit, it can no longer act as the pivot between the two rows of wrist bones. The neighboring bones shift into faulty positions, the loads on the joint move, and the cartilage wears out prematurely.
Wear that follows a known path
This deterioration is not random: it follows a predictable sequence, described and classified by surgeons, that begins in a limited area of the wrist and spreads step by step to the neighboring joints.
What matters for you is not the name of this sequence but its logic: it moves in one direction only, and it never reverses. Once cartilage is worn away, it does not grow back. This is what makes timing the single most important factor in the entire course of care.
Hence a major practical consequence: the right time to treat a nonunion is before it hurts too much. Waiting for the pain to become clear-cut often means waiting until the wear is already established.
How it is found
An incidental finding on an X-ray taken for another reason: the nonunion was there, silent.
A work-up after a mislabeled sprain: what had been taken years earlier for a simple sprain turns out to have been an unhealed fracture.
The examination often finds tenderness when pressing on the scaphoid and limited wrist movement, particularly backward (the "push-up" position).
Imaging, which guides the whole decision
This is where the strategy is decided, because two questions entirely determine what can be offered.
Is the cartilage still intact?
The X-ray, supplemented if needed by a CT scan, looks for the first signs of osteoarthritis. This is what distinguishes a "repairable" nonunion from one that is already complicated.
Is the upper fragment still alive?
MRI assesses its blood supply. A devitalized fragment changes the reconstruction technique.
The CT scan also clarifies the geometry of the nonunion and any deformity of the bone, which often takes on a bent appearance.
The treatments: reconstruct, or compensate
The whole logic hinges on one tipping point: as long as the cartilage is preserved, the goal is to reconstruct the scaphoid; once osteoarthritis has set in, the bone is no longer repaired and the worn wrist is treated instead. These are two different surgical worlds, and it is timing that tips you from one to the other.
As long as the wrist is not worn: reconstruct the bone
The goal is to finally achieve healing. The approach most often combines a bone graft — to fill and stimulate the area that will not knit — with fixation, usually a screw, to hold the fragments still while they heal.
Two main families of grafts exist, and recent data help place each one accurately:
The simple bone graft
Taken, for example, from the radius or the crest of the iliac bone. It is the standard treatment for most nonunions.
The vascularized graft
It brings bone tissue along with its own blood-supply pedicle.
What the studies show, which tempers a common belief
Across nonunions as a whole, the simple graft and the vascularized graft give comparable healing rates — on the order of 85 to 90%. So the vascularized graft is not superior "as a matter of principle."
On the other hand, when the upper fragment is necrotic, the vascularized graft regains the advantage: studies report markedly better healing rates in this specific situation. That is where it is indicated.
Another useful figure: nonunions without necrosis and without involvement of the upper fragment heal in more than 95% of cases. The outlook therefore depends closely on the condition of the bone — and that condition deteriorates over time.
When osteoarthritis is already present: treat the wrist, not the bone
If the cartilage is already worn, reconstructing the scaphoid no longer makes sense: it would articulate with damaged surfaces. The strategy changes completely, and now aims to relieve pain by reorganizing or simplifying the wrist. See the wrist osteoarthritis article.
Several procedures exist, chosen according to the extent of the wear and the patient's needs:
Removal of the first row of carpal bones, which eliminates the diseased surfaces, with resurfacing of the head of the capitate using an RCPI implant if needed.
Partial fusions, which lock part of the wrist while preserving some mobility, with removal of the scaphoid.
Removal of a fragment, removal of the tip of the radius, or other targeted procedures depending on the stage.
In the most advanced forms, complete fusion of the wrist, which removes the pain at the cost of mobility, as a last resort.
These procedures give good results for pain, but none restores a brand-new wrist. That is precisely what we aim to avoid by treating the nonunion earlier.
The overall picture
This table sums up the essence of the article in three lines: the surgery that is possible depends on the condition of the wrist, and that condition only deteriorates as long as the nonunion goes untreated.
Recovery
After a graft, healing takes several months, confirmed by imaging before any loading is allowed. Immobilization and then rehabilitation follow a schedule specific to each procedure.
One thing to know: even after healing is achieved, wrist mobility and strength do not always return to exactly what they were, especially if the nonunion was long-standing. The realistic goal is a pain-free, functional wrist, not necessarily a brand-new one.
The exact details depend on the technique used: contextualized cases are presented in our knowledge center.
Frequently asked questions
Glossary
Failure of a fracture to heal, the fragments remaining mobile like a false joint.
The bony bonding that unites the fragments of a fracture.
Bone taken from elsewhere on the patient, to fill and stimulate an area that will not knit.
A graft brought with its own blood-supply pedicle, useful when the fragment has lost its blood supply.
Death of a bone fragment deprived of its blood supply.
Surgical locking, complete or partial, of a joint to eliminate pain.
References
Duncumb JW, Robinson PG, Williamson TR, et al. Bone grafting for scaphoid nonunion surgery: a systematic review and meta-analysis. Bone Joint J. 2022;104-B(5):549-558 — 78 studies, 7,671 patients; healing ~88.7% (simple graft) vs ~87.5% (vascularized), with no significant difference; >96% in the absence of necrosis and proximal pole involvement
Graft choice for managing scaphoid non-union: umbrella review. Hand Surg Rehabil. 2024 — vascularized graft superior in cases of proximal pole necrosis (74-88% vs 47-62%)
Predictors of Failure for Vascularized and Nonvascularized Bone Grafting of Scaphoid Nonunions: A Systematic Review. PMC9666072
Scapholunate Advanced Collapse (SLAC) and Scaphoid Nonunion Advanced Collapse (SNAC): A Review of Treatment Options. Cureus. 2024 — predictable degenerative sequence, from the radioscaphoid to the midcarpal joint; surgical options by stage
Scapholunate and scaphoid nonunion advanced collapse wrist arthritis. PMC3702758 — predictable four-stage progression described by Watson
Vascularized Versus Non-vascularized Bone Grafting for Scaphoid Non-union: A Meta-Analysis. Cureus. 2025 — scaphoid nonunion rate of 10-15%; vascularized graft associated with a shorter time to healing
Epidemiology and risk factors of scaphoid nonunion
Radiographic classification of the SNAC sequence and its correspondence with indications
Long-term functional outcomes of partial fusions and first-row resection
Reviewed and approved by Dr Frédéric Teboul, surgeon of the hand, brachial plexus, and peripheral nerves, member of the Académie Nationale de Chirurgie.
Last updated: August 20, 2026
Disclaimer. This article is for informational purposes. It does not replace a medical consultation. Persistent wrist pain, even long-standing, deserves specialist advice.
Author of this publication
Every piece of content is signed by its author and reviewed before publication.
Author
Dr Frédéric Teboul
Hand surgeon — specialist in the brachial plexus and peripheral nerves