A scaphoid (navicular) fracture is a break in one of the small bones of the wrist. This type of fracture occurs most often after a fall onto an outstretched hand.

The Anatomy of the Wrist

The carpal scaphoid bone is a small C-shaped bone located on the radial side – or thumb side – of the wrist. It is shaped much like a very fat potato chip, and helps connect the wrist and thumb. 

It is also in a very critical biomechanical position in the wrist, located between two rows of wrist or carpal bones. It is the most frequently broken of all little wrist or carpal bones, often due to a fall. 

There are both compressive and tension forces exerted on this bone during a fall. The scaphoid bone may be broken in the mid waist portion (most common), the distal portion (near the thumb), or the proximal portion near the mid-wrist.

The Difficult Healing Process

Scaphoid fractures are subject to a difficult healing process. The blood supply to the scaphoid bone is unusual, entering the bone from the radial side (thumb side) and traveling back towards the wrist. Unfortunately, a fracture of the scaphoid may disrupt the blood supply to the bone, leaving one half without blood supply. This can result in delayed healing or nonhealing of the fracture. 

In general, healing of the proximal scaphoid fractures are the most difficult recoveries (followed by waist fractures). However, distal scaphoid fractures, in most cases, have a relatively good blood supply and heal normally.

The Difficult Diagnosis

Scaphoid fractures are the most commonly missed wrist bone fracture. Often, a patient will believe that they have sprained their wrist and will treat their injury conservatively. In these cases, they may do well for years – until chronic wrist discomfort appears. 

X-rays will then reveal a chronic nonunion or nonhealing of the fracture, with some collapse of the scaphoid and degenerative changes in the scaphoid (as well as wrist arthritis). The natural history of non-treated scaphoid fractures reveals a high rate of nonunion and progressive development of wrist arthritis over a 10 to 15 year period.

Unfortunately, even if initial medical care is received after a fall, the first x-rays may appear negative, and the fracture will remain undetected until later. A high index of suspicion is sometimes necessary to recognize and treat this injury early.

With this in mind, it is important to completely evaluate the scaphoid fracture pattern and alignment in order to prepare a complete treatment plan. This may involve:

• taking special x-rays
• using a CT scan or MRI to assess the alignment and blood supply of the scaphoid
• combining imaging tests and exams to find the exact location and orientation of the fracture
• establishing if the fracture is well aligned and nondisplaced; flexed and compressed; or apart and separated
• determining if existing patient factors (such as age, general health, smoking, and malnutrition) will affect the scaphoid healing process

The Treatments

Treatment of scaphoid fractures are highly discussed and are sometimes controversial. Many research papers and academic discussions focus on the treatment of scaphoid fractures. As a result, treatment plans are varied in different areas of the country and even among different surgeons.

Pittsburgh Foot and Hand Center has taken a moderate but occasionally aggressive approach to scaphoid fracture treatment, based on our extensive experience with treating both acute fractures and chronic fracture nonunions referred to us for treatment by other orthopedic surgeons. 

Truly nondisplaced scaphoid fractures, confirmed by CT scan and seen right away, may be treated conservatively in young healthy patients (especially in cases of distal scaphoid fractures). 

• A long-arm thumb spica cast above the elbow is usually applied for 6 weeks with a short arm thumb spica cast used afterwards until the fracture is healed. 
• The patient will be started on vitamin D and calcium supplements to help bone healing. 
• An external bone stimulator may also be used to help assist healing.

Even with direct and immediate recognition of a fracture and treatment, however, nondisplaced fractures sometimes occasionally are delayed in healing or do not heal. In those cases, internal fixation with a screw and placement of a bone graft in the fracture site may be required. 

For athletes and/or for proximal pole fractures, early percutaneous screw fixation may be utilized. 

• A small incision is made over the wrist and a small screw placed (with x-ray guidance) across the fracture site to compress it and improve healing percentages. 
• After surgery, a short arm thumb spica cast or splint including the thumb is used.
• Gentle early wrist motion may be initiated earlier due to screw fixation. 

Although the odds are improved, there are cases of delayed healing or nonhealing with this technique also.

In cases of displaced scaphoid fractures or chronic scaphoid nonunions, open reduction and internal fixation (ORIF) may be utilized.

• In this surgery, an incision is made on the palmar side or dorsal side (back) of the wrist over the fracture.
• The fracture alignment is corrected (reduced). 
• In cases of chronic nonunion, an area of cystic degeneration or fiber scar tissue may exist at the fracture site and require removal. 
• If a gap exists after reducing the fracture, that space is filled with a bone graft, usually taken from the adjacent radius. 
• A compressive screw is then placed across the fracture under x-ray guidance and the fracture is stabilized. 
• The soft tissue is then closed in a protective thumb spica splint or cast.
• Vitamin D and calcium supplements, as well as an external bone stimulator, may be used to help healing. 
• In cases of chronic scaphoid nonunion where arthritis of the wrist has already developed, another procedure – such as removal of the scaphoid and proximal row carpectomy or wrist fusion – may be required for treatment. 

The general risks with the treatment of scaphoid fractures are anesthesia-related risks, wound healing problems or infection, delayed healing or nonhealing of the fracture, as well as the development of wrist arthritis.

Unfortunately, sometimes despite our best and most aggressive treatments, the fracture simply does not heal.