Pseudarthrosis of the scaphoid bone (scaphoid nonunion)

Anatomy and peculiarities of the scaphoid

The scaphoid lies on the thumb side of the carpus and connects the proximal and distal carpal rows. Due to its central location, it significantly controls the stability and mobility of the wrist.

• Blood supply: predominantly from distal (from the side away from the palm) towards proximal. This makes the proximal pole sensitive to circulatory disorders.
• Mechanics: The scaphoid transmits forces from the hand to the forearm and is particularly at risk in the event of a fall.
• Healing risk: The limited blood supply, fine bone structure and constant micro-movements make fracture healing difficult.

What does scaphoid pseudoarthrosis mean?

A nonunion occurs when a broken piece of bone does not heal stably within the expected period of time. For the scaphoid, a period of around 3-6 months is considered the threshold. Instead of a solid bone bridge, an unstable false joint is formed with persistent pain and loss of function.

• Early non-union (delayed union): delayed healing, in principle still potentially capable of consolidation.
• Pseudarthrosis (nonunion): lack of bony healing, often with sclerosis of the fracture ends and misalignment.
• Accompanying problems: circulatory disorder of the proximal pole (AVN) and progressive carpal deformity up to the SNAC stage.

Causes and risk factors

The scaphoid nonunion is often caused by a scaphoid fracture that was initially overlooked or inadequately treated. Due to the complex blood supply and high mechanical stress, the scaphoid is susceptible to non-healing.

• Missed fracture: initially only mild discomfort, normal x-rays can hide the fracture.
• Inadequate immobilization or loading too early.
• Location: Fractures of the proximal pole heal more slowly.
• Smoking and nicotine consumption have been shown to impair bone healing.
• Malnutrition, vitamin D deficiency, systemic diseases (e.g. diabetes).
• Malposition at the fracture site (humpback deformity) with disturbed kinematics.

Symptoms: How do you recognize a nonunion?

• Chronic, stress-dependent pain on the thumb side of the wrist (Tabatière).
• Pressure pain in the “anatomical snuff pit”.
• Loss of strength when grasping, opening a bottle or doing push-ups.
• Restriction of movement, especially when leaning backwards and to the side.
• Occasional clicking/feeling of instability.
• Later: pain at rest, swelling, signs of early arthrosis.

Diagnostics: Imaging with a clear mission

A structured diagnosis clarifies whether there is a nonunion, how the fracture occurs, whether there are circulatory problems and whether consequential damage has already occurred.

It is also important to assess the stage of possible SNAC (early signs to advanced carpal collapse), as the strategy is derived from this.

Conservative therapy: possibilities and limits

Purely conservative treatment rarely leads to bony healing in the case of a manifest scaphoid nonunion. It can still be useful to relieve pain, maintain function or optimally prepare for an operation.

• Immobilization: individually adapted orthosis/splint, temporary relief during peak loads.
• Physiotherapy: maintaining mobility, muscular balance, strength exercises that are gentle on the joints, scar care after procedures.
• Pain management: gradual analgesics as needed, local measures (cold, tape), anti-inflammatory strategies.
• Smoking cessation and bone health: Vitamin D, calcium, adequate protein intake - after consultation with a doctor.
• Bone stimulators (e.g. LIPUS/PEMF): may be considered in selected cases; The study situation is heterogeneous and the benefit is not guaranteed.
• Shock wave therapy: inconsistent evidence for scaphoid nonunions; only after individual consideration.

Conservative measures do not replace causal stabilization if there is instability, misalignment or circulatory problems. However, they can reduce symptoms and are part of a holistic treatment concept.

Surgical therapy: differentiated and targeted

If the nonunion is secured or there is a relevant malposition or AVN, surgical reconstruction is usually recommended. The aim is to restore the axes, provide stable compression of the fracture and promote bone healing.

• Screw osteosynthesis with spongiosaplasty (e.g. Russe/Matti-Russe technique): Filling the defect with the body's own bone (iliac crest or radius) and fixation with a head-hole or cannulated screw.
• Vascularized bone transfer: for circulatory disorders, especially a. 1,2-ICSRA flap (arterial pediculated bone chip from the radius) or free chip (e.g. medial femoral condyle).
• Correction of Humpback Deformity: Restoring the length/curvature of the scaphoid to normalize kinematics.
• Arthroscopically assisted procedures: gentle soft tissue treatment, precise reduction and defect preparation.
• Salvage procedures for advanced osteoarthritis (SNAC II–III): e.g. B. proximal row carpectomy, partial wrist fusion (four-corner arthrodesis) or selective styloidectomy - depending on the findings and activity requirements.

Which technique is chosen depends on the location (distal/central/proximal), age of the nonunion, malposition, quality of the bone ends and blood flow. Careful information about opportunities and risks is a given.

Risks and possible complications

• Lack of development (persistence of the nonunion).
• Continued misalignment or secondary development of osteoarthritis.
• Screw loosening, material irritation, rarely material breakage.
• Wound healing disorders, infection (rare), scarring problems.
• Sensitive irritation/nerve irritation in the access area.

Overall, complications are rare. Realistic expectations and consistent follow-up treatment improve the results.

Follow-up treatment and rehabilitation

Patience is required after a reconstruction of the scaphoid. Follow-up treatment is planned individually and depends on stability, technique used and accompanying findings.

Avoiding nicotine, sufficient protein intake and vitamin D optimization can support bone healing. Please coordinate nutritional supplements with the treatment team.

Forecast: what does the result depend on?

• Fracture location: proximal poles heal more difficult.
• Time until treatment: the earlier, the cheaper.
• Presence of a circulatory disorder (AVN).
• Extent of misalignment and carpal static.
• Risk factors such as smoking or metabolic diseases.
• Consistent follow-up treatment and compliance.

The goal is a stable, pain-reduced hand with everyday function. Not every limitation can be completely eliminated - good but not perfect results are often achieved, especially with advanced osteoarthritis.

Everyday life, work and sport

• Everyday life: light activities possible early on, heavy gripping loads only after approval.
• Occupation: Office work often after 1-2 weeks, manual tasks later; individual coordination required.
• Sports: cycling/ergometer early, swimming moderately, contact sports and sports with a risk of falling (e.g. snowboarding) only after consolidation.
• Ergonomics: Aids such as wrist wraps and non-slip handles can make transition phases easier.

Prevention and self-help

• Clarify early: persistent Tabatière pain after a fall should be examined promptly with imaging – even if the initial X-ray is normal.
• Quitting smoking: improves bone healing.
• Bone health: get vitamin D checked; balanced diet.
• Protection: Wrist guards for high-risk sports.
• Adherence to therapy: wear the splint/orthosis consistently, attend check-ups.

When should I seek medical attention?

• Persistent pain on the thumb side of the wrist for several weeks.
• Increasing swelling, pain at rest or pain at night.
• Feeling of instability or “folding away” when supported.
• Numbness/tingling, new limitation of movement.
• After an operation: redness, overheating, fever or discharge of secretions.

Your hand orthopedic care in Hamburg

In our orthopedic practice at Dorotheenstrasse 48, 22301 Hamburg, we provide you with evidence-based and individual advice. We value a conservative, joint-preserving strategy whenever it makes medical sense. If an operation is recommended, we will explain the procedure, alternatives and the realistic course of action - without making excessive promises.

Bring any existing X-rays, CT or MRI images with you to the initial consultation. This means we can give a precise assessment more quickly and plan the next steps with you.

Scientific classification – briefly explained

The evidence base for the treatment of scaphoid nonunion is differentiated: CT-based healing assessments are considered standard. Vascularized bone transfers show advantages in AVN of the proximal pole, while cancellous bone grafts with stable screw osteosynthesis can achieve excellent results in well-perfused areas. Nonsurgical bone stimulation methods are discussed, but data quality is heterogeneous. The selection of the procedure should therefore be individual and image-based.