Nonunion after fractures of the hand and wrist

What is a nonunion?

A nonunion (non-union) describes impaired bone healing in which the fracture does not lead to stable bony development even after sufficient time. A period of around 6-9 months is often used; However, clinical symptoms and lack of signs of healing on imaging are crucial. A distinction is made between hypertrophic (lots of callus, too much movement) and atrophic nonunions (too little bone healing activity, often circulatory problems).

In the hand, scaphoid pseudoarthrosis is a typical special case: the scaphoid is subjected to a lot of stress in everyday life and has comparatively poor blood supply in certain areas. If a fracture remains undetected or is inadequately immobilized, a nonunion can occur, which in the long term leads to a specific form of wrist wear (SNAC).

Causes and risk factors

Bone healing requires stability, good blood circulation and sufficient biological healing potential. Disturbances in one or more of these areas increase the risk of nonunion.

• Mechanical: inadequate immobilization, unstable osteosynthesis, repeated microtraumas, axial misalignment
• Biological: restricted blood flow (e.g. proximal scaphoid), extensive soft tissue injury, infection
• Patient factors: nicotine consumption, diabetes mellitus, malnutrition/vitamin D deficiency, older age, anemia
• Fracture-related factors: fracture gap, bone loss, comminuted zone, open fracture
• Medication/General: long-term high-dose NSAID use, corticosteroids, osteoporosis

Not every risk factor necessarily leads to nonunion. Careful initial treatment of the fracture, consistent immobilization and structured follow-up checks significantly reduce the risk.

Frequent special shapes on the hand and wrist

Depending on the bone and location, nonunions take different courses and require adapted therapy strategies.

• Scaphoid pseudoarthrosis: typical for overlooked or prematurely stressed scaphoid fractures; Risk of humpback deformity, DISI malalignment and later SNAC osteoarthritis.
• Metacarpal bones (metacarpals): Nonunions are rare and tend to occur after complex fractures or infections; Loss of stability and function with reduced grip strength.
• Finger bones (phalanges): cannot heal after open injuries or tendon-joint involvement; Danger of stiff, painful fingers.
• Distal radius/ulna region: rare nonunion, often with axial deviation; influences the entire wrist kinematics.

Symptoms: How can you recognize a nonunion?

• Persistent, stress-related pain months after the fracture
• Feeling of instability, “crunching” or pain with certain movements
• Loss of strength, uncertainty when gripping or supporting
• Tendency to swell, local tenderness
• Occasionally visible misalignment or shortened finger
• In the case of infectious pseudoarthrosis: warmth, redness, impaired wound healing, possibly fever

Symptoms alone do not prove nonunion. A confirmed diagnosis is based on clinical examination and targeted imaging.

Diagnostics: This is how we proceed

The clarification in our practice in Hamburg is structured. What is important is the original mechanism of injury, previous treatment and the course of the symptoms over time.

Monitoring the progress is crucial: If there is no progress in healing over a period of weeks to months and symptoms persist, the likelihood of a nonunion increases.

Conservative therapy: options without surgery

In cases of delayed healing (delayed union) and selected nonunions with little mobility in the fracture gap, a conservative approach may be promising. We rely on low-risk measures whose benefits are weighed up individually.

• Immobilization/splinting: temporary immobilization to reduce micro-movement
• Optimization of the healing conditions: nicotine avoidance, adequate protein and calcium intake, vitamin D optimization, control of diabetes
• Physiotherapy and occupational therapy: painless mobilization of unaffected joints, edema reduction, muscle balance
• Bone stimulation: low-energy ultrasound (LIPUS) or electromagnetic fields; can support healing, evidence varies depending on location
• Pain management: gradual analgesia; NSAIDs only targeted and for a limited time
• Infection control: if suspected, antibiotic therapy only after pathogen detection and in combination with surgical cleansing

Conservative options make more sense the more stable the situation is and the shorter the time since the fracture. If symptoms and radiographic signs remain unchanged, surgical stabilization should be considered.

Surgical treatment: restore stability and biology

The goal of surgical procedures is to create mechanical stability and promote biological healing. The procedure depends on the location, type and duration of the nonunion as well as accompanying factors such as blood flow and axial deviation.

• Scaphoid nonunion: reduction with correction of humpback deformity, screw osteosynthesis (e.g., cannulated compression screw) plus cancellous bone graft (often from the distal radius). If the proximal pole is non-vital: vascularized bone transplant possible.
• Metacarpals/phalanges: stable plate/screw osteosynthesis with cancellous plastic; Correction of axis and rotation errors.
• Distal radius/ulna: corrective osteotomy with angle-stable plate and bone graft for malposition and nonunion.
• Infectious pseudoarthrosis: two-stage procedure with debridement, germ cleansing, temporary stabilization and subsequent reconstruction.
• Salvage procedure: In cases of advanced joint wear and the situation cannot be reconstructed, e.g. B. partial arthrodesis, resection arthroplasty or denervation procedures; The focus is on reducing pain and maintaining function.

Additional biological procedures such as growth factors are used on the hand selectively and according to strict indications. They do not replace the necessary mechanical stability. A promise of healing cannot be made; Realistic goals are pain relief and functional improvement.

Aftercare and rehabilitation

Follow-up treatment is crucial for the success of therapy. It is individually coordinated with hand surgery, physiotherapy and occupational therapy.

• Immobilization: usually 4–8 weeks depending on location and stability; Scaphoid more often longer.
• Early function: joint-friendly mobilization of adjacent joints to avoid stiffness.
• Hand therapy: scar care, edema control, coordination, grip strength building.
• Imaging follow-up checks: X-ray/CT to assess the bony structure.
• Adjustments to everyday life and the workplace: gradual increase in load, advice on aids.

The return to sport and heavy physical work depends on healing progress and stability. Exercising too early jeopardizes the success of the therapy.

Course and prognosis

The prognosis depends on the location, duration of the nonunion, mechanical correction and biological vitality. With timely recognition and adequate treatment, good functional results are possible.

• Scaphoid: if untreated, SNAC threatens with radiocarpal and midcarpal osteoarthritis; early correction improves prospects.
• Metacarpals/phalanges: after stable reconstruction, usually good consolidation, rehabilitation to avoid stiffness is essential.
• Infectious nonunions: require patience and step-by-step concepts; Complication rates higher.

Important: Even after successful consolidation, there may be remaining movement restrictions or load limits. The aim is to achieve a functional level that is suitable for everyday use and has as little discomfort as possible.

Prevention: This is how the risk can be reduced

• Detect fractures early and treat them according to guidelines, including appropriate immobilization
• Undertake regular follow-up checks
• Avoid nicotine, eat a balanced diet, optimize your vitamin D status
• Control diabetes well, diagnose and treat osteoporosis
• Increase load slowly and wear splints/orthoses consistently

When should you seek medical advice?

• Pain and swelling persist for weeks despite treatment
• Increasing misalignment, decreasing grip strength or new instability
• Tingling, numbness or poor circulation in fingers
• Redness, warmth, weeping sore, fever or chills
• Uncertainty as to whether the current immobilization/stress is appropriate

If there are any warning signs, we recommend a prompt clarification. In acute situations, please contact an emergency room.

Your treatment in Hamburg-Winterhude

In our practice at Dorotheenstraße 48, 22301 Hamburg, we combine precise diagnostics with a conservative, function-oriented therapy concept. Wherever possible, we treat without surgery and systematically optimize healing conditions.

If an operation makes sense, we will provide detailed advice on options, benefits and risks and, if desired, organize a consultation with experienced hand surgeons in our network. We coordinate conservative pre- and post-treatment, including hand therapy, close to home.

Our goal is realistic, transparent planning: reduce pain, improve function, avoid consequential damage - without any promise of cure, but with a clear structure and close support.

Please feel free to make an appointment via Doctolib or by email. We advise you clearly and individually.

Secondary consequences: joint wear and instability

Untreated nonunions can disrupt the kinematics of the wrist and secondarily lead to arthrosis in different parts of the joint. This is particularly true for scaphoid nonunion, which leads to characteristic wear patterns.

• Radiocarpal osteoarthritis: Wear between the radius and the proximal carpal row
• Midcarpal osteoarthritis: wear and tear in the middle carpal row
• STT osteoarthritis: Wear between the scaphoid, trapezium and trapezoid
• Unstable wrist kinematics: Ligament lesions/misalignments promote instability

The earlier the malunion is recognized and treated, the easier it is to avoid or mitigate such consequential damage. If the wear and tear is advanced, joint-preserving and joint-stiffening options are up for discussion; The decision is made after individual consideration.