Scaphoid Fracture

Original Editor - Dawn Waugh

Top Contributors - Dawn Waugh, Mats Vandervelde, Inoa De Pauw, Evan Thomas and Kim Jackson

Definition/ Description

Scaphoid bone (left hand) - animation.gif

The scaphoid bone is the most commonly fractured carpal bone. In young children and the elderly population scaphoid fractures are rare. The scaphoid bone is stronger than the relative weak distal radius compared in these age groups.[1][2] A delay in diagnosis of scaphoid fractures can lead to a variety of adverse outcomes that include nonunion (no consolidation) , delayed union, decreased grip strength and range of motion, and osteoarthritis of the radiocarpal joint. Timely diagnosis, appropriate immobilization, and referral when indicated can decrease the likelihood of adverse outcomes.[3][2]

Clinically Relevant Anatomy

Scaphoid bone (picture of only the bone) - animation1.gif

The scaphoid is one of the 8 carpal bones ( the largest) of the wrist. (see image) It’s an important boat-shaped carpal bone that articulates with the distal radius, trapezium, and capitate. During dorsiflexion and radial deviation of the wrist, the motion is limited by the scaphoid conflict on the radius.

  • Anatomically, the scaphoid has proximal and distal poles with a waist between the two.
  • Blood supply to the scaphoid bone is predominantly from branches of the radial artery (dorsal carpal branch).
  • These enter the dorsal ridge and supply the 80% of proximal pole via retrograde flow.
  • The second source is from the superficial palmar arch, a branch of the volar radial artery, which enters at the distal tubercle and supplies the distal pole.
  • The retrograde nature of the blood supply means that fractures at the waist of the scaphoid leave the proximal pole at high risk of avascular necrosis.
  • The majority of fractures (approximately 65%) occur at the waist, with a quarter at the proximal third and 10% the distal third[4].
  • Scaphoid fractures are common, but present unique challenges because of the particular geometry of the fractures and the tenuous vascular pattern of the scaphoid. Delays in diagnosis and inadequate treatment for acute scaphoid fractures can lead to nonunions and subsequent degenerative wrist arthritis.[5]

Etiology

Patients typically present with wrist pain following a fall onto an outstretched hand.

  • Axial loading of the wrist with it in forced hyperextension and radial deviation can cause the fracture as the scaphoid impacts on the dorsal rim of the radius.
  • Contact sports and road traffic accidents are also common causes.[4]

Epidemiolgy

  • Scaphoid fractures predominantly affect young adults, with a mean age of 29 years.
  • There is a higher incidence in males.
  • Unusual in the pediatric population and the elderly population where the physis or distal radius, respectively, are more likely to fracture first.
  • Scaphoid fractures account for 15% of acute wrist injuries.[4]
  • Scaphoid fractures have a high incidence of nonunion (8-10%), frequent malunion, and late sequelae of carpal instability and posttraumatic arthritis[6].
  • No blood vessels enter the proximal pole of the scaphoid, thus a higher incidence of aseptic necrosis and nonunion is noted with fractures on this side of the scaphoid [6].
  • Displaced fractures frequently are associated with ligamentous tears in the wrist. So evaluation and follow-up is recommended[6].

Characteristics/ Clinical Presentation

The main cause of injury is a fall on the outstretched hand with an radially deviated wrist, which results in extreme dorsiflexion at the wrist and compression to the radial side of the hand. There will be a massive force of the hand on the arm through the scaphoid bone[1][2][7]. The patient experience a deep, dull ache in the radial part of the wrist. The pain, which often is mild, is aggravated by pinching and gripping. The wrist can be lightly swollen or bruised and, possibly, fullness in the anatomic snuffbox, suggesting a wrist effusion. Scaphoid fractures are most common in males 15 to 30 years of age[7] and are rare in young children and infants.[1]

Differential Diagnosis

These diagnoses can be differentiated by the location of tenderness, pain with certain maneuvers, and radiographic abnormalities.[2][8]

  • Distal radius fracture
  • Other carpal bone fractures
  • Scapholunate dissociation
  • Dequervain’s tenosynovitis
  • Osteoarthritis
  • Tendonitis[4]

Diagnostic Procedures

Bone scintigraphy has been advocated by many as the ideal investigation for occult scaphoid fractures. It has been shown to have 100% sensivity and 98% specificiteit for scaphoid fractures compared with only 64% for plain radiography. The clinical signs of a scaphoid fracture were swelling and tenderness in the anatomical snuff box. Research has shown that the use of MRI is effective to determinate a scaphoid fracture. Both methods found all fractures, but the MRI found some significant ligamentous and carpal instabilities. The bone scintigraphy was a cost-effective and accurate method for assessing occult scaphoid fractures compared with repeat plain radiography.[9][10]

Retrieved from:Kawamura, K. & Chung, K.C. Hand Surg Am. (2008) Jul-Aug; 33(6): 988–997. doi: 10.1016/j.jhsa.2008.04.026

Outcome Measures

  • PRWE, a fifteen-item questionnaire was designed to measure wrist pain and disability. The reliability was excellent (ICCs > 0.90). Validity assessment demonstrated that the instrument detected significant differences over time (p < 0.01).[7]
  • PEM, the Patient Evaluation Measure has a simple layout with questions asked in a visual analogue form. Patients are asked to read and comprehend the question alone and not the description of each interval answer.[6]

Examination

When examining a patient with a suspected scaphoid injury, it is important to compare the injured wrist with the uninjured wrist. The classic hallmark of anatomic snuffbox tenderness on examination is a highly sensitive (90 percent) indication of scaphoid fracture, but it is nonspecific (specificity, 40 percent)[1] For example, a false-positive result can occur when the radial nerve sensory branch, which passes through the snuffbox, is pressed and causes pain. Other physical examination maneuvers should be performed. Tenderness of the scaphoid tubercle (i.e., the physician extends the patient’s wrist with one hand and applies pressure to the tuberosity at the proximal wrist crease with the opposite hand) provides better diagnostic information; this maneuver has a similar sensitivity (87 percent) to that of anatomic snuffbox tenderness, but it is significantly more specific (57 percent)[1] Absence of tenderness with these two maneuvers makes a scaphoid fracture highly unlikely.

Pain with the scaphoid compression test (i.e., axially/longitudinally compressing a patient’s thumb along the line of the first metacarpal) also was shown, in a retrospective analysis[3], to be helpful in identifying a scaphoid fracture, but in another study[2], this technique had a poor predictive value for identifying scaphoid fractures. Another maneuver that suggests fracture of the scaphoid is pain in the snuffbox with pronation of the wrist followed by ulnar deviation (52 percent positive predictive value, 100 percent negative predictive value)[2][2]

Medical Management

Suspected fractures in those with positive clinical findings on examination but negative radiographs should have a followup with films repeated in 7-14 days. If pain persists and radiographs are still normal, then further imaging in the form of MRI or CT should be undertaken. Pain management with assistance of pharmacist should be considered.

Nonoperative management

  • Fractures which are non-displaced and within the distal third of the bone can be managed non-operatively with immobilization in a cast.  Debate exists as to whether a long or short arm cast is optimal and whether a thumb spica should be included to immobilize the thumb, no evidence currently suggests one option is better than the other.
  • The cast usually needs to remain on for six weeks with repeat radiographs taken at this time to assess for union. Time to union varies depending on the location of the fracture. The distal-third would be expected to heal within 6-8 weeks, middle-third within 8-12 weeks and proximal third within weeks.  The relative increase in time to healing while moving from distal to proximal is secondary to the tenuous blood supply and retrograde arterial flow.[4]

Surgical Management

Indications for operative management include:

  • Displacement greater than 1mm
  • An intrascaphoid angle greater than 35 degrees (humpback deformity)
  • A radiolunate angle of more than 15 degrees
  • Transcaphoid perilunate dislocation
  • Proximal pole fractures
  • Comminuted fractures
  • Non displaced waist fractures in individuals that need to return quickly to work/sport
  • Nonunion or avascular necrosis

Surgical fixation involves the insertion of a single or multiple screws and can be done percutaneously or via an open procedure. The latter is preferable for non-unions and those fractures that exhibit gross displacement with the former for acute, minimally displaced fractures[4].

Physical Therapy Management

As a basic rule, in a patient with a clinically suspected scaphoid fracture but negative initial radiographs, it is reasonable to apply a short arm thumb spica and reevaluate the patient in two weeks. If a cast is not applied, the fracture can worsen over the following months. MRI or bone scintigraphy may be used initially if the patient desires an alternative approach. At the two-week visit, the patient should be free of pain, and a follow-up radiograph should be obtained.[2]

Scaphoid fracture types.gif

The fractured scaphoid exhibits certain behavior that inhibits healing. Fracture fragments are inherently unstable and prone to displacement, and require motionless contact to achieve union.[6] As mentioned before, the blood supply of the scaphoid is tenuous. For therapeutic decision making, the scaphoid is divided into three anatomic sections: proximal, medial, and distal. Fractures are further subdivided into displaced and non-displaced types.[2]

Nondisplaced Fractures
Nondisplaced distal fractures heal well with strict immobilization in a well-molded short arm thumb spica. Controversy exists over whether to use a long arm or a short arm cast. One comparison, [8]found that nondisplaced fractures healed well regardless of the type of cast that was used. Current treatment for this type of fracture is a thumb spica, but some evidence suggests that the thumb could be omitted from the cast. A randomized prospective trial[9], found that immobilization of the thumb did not improve outcomes for nondisplaced fractures. Screw fixation may speed recovery to pre-injury activities; referral for surgery may be indicated, depending on the needs of the patient[10]. As the fracture line moves proximally, there is more risk of displacement and nonunion; therefore, it would be appropriate to refer these patients for orthopedic consultation. If conservative treatment is attempted, a long arm cast with thumb immobilization is appropriate.[2][11]

Displaced Fractures
Fractures with even small amounts of displacement are prone to nonunion, and operative treatment is recommended[1].  For the fixation, double-threaded headless screws are preferred. Wich operative technique to use depends on the fracture morphology.[12] Splinting and referral are indicated.[2]

Traditionally, undisplaced and stable scaphoid fractures are treated by casting in short- or long-arm casts. After the immobilization you must start with stretching exercises en strengthening exercises.[3][2]

Stretching exercises:

  • Flexion: bend your wrist forward
  • Extension: bend your wrist backward
  • Radial and ulnar deviation: move your wrist side to side
  • Wrist stretch: press the back of the hand on your injured side with your other hand to help bend your wrist.
  • Wrist extension stretch: Stand at a table with your palms down, fingers flat, and elbows straight. Lean your body weight forward.

Strengthening exercises:

  • Wrist flexion and extension: Hold a weight in your hand and bend your wrist upward and downward.
  • Finger flexion an extension: exercises with a powerweb™
  • Forearm pronation and supination: keep your arm in an angle of 90°, Turn your palm up and hold for 5 seconds. Then slowly turn your palm down and hold for 5 seconds.[2]



Revalidation week to week


Rehabilitation considerations immediately following injury to 1 week[6]

For casted fractures

  • Active range of motion (AROM) and passive range of motion (PROM) to the digits, except the thumb, which is immobilized
  • AROM and active-assisted range of motion (AAROM) exercises to the shoulder
  • Isometric exercises to the biceps, triceps, and deltoid muscles

Following open reduction internal fixation (ORIF) surgery

  • Elevation of the arm to treat dependent edema
  • AROM and PROM of digits, except the thumb
  • AROM and AAROM exercises to the elbow and shoulder
  • Isometric exercises to the biceps, triceps, and deltoid muscles
  • Limitation of supination and pronation

Rehabilitation considerations in 2 weeks[6]

The clinician may obtain bone or CT scans in the event of continued pain and tenderness over the snuffbox with negative radiographic findings.
Bone stimulators have been increasingly used for stable, non-displaced fractures and for suspected scaphoid fractures with negative radiographic findings, although both uses are still somewhat controversial.
A short-arm cast is indicated for a suspected fracture, while a long-arm cast is used for a known fracture.
The patient should continue ROM exercises for casted fractures and ORIF, as above.

Rehabilitation considerations in 4-6 weeks[6]

For casted fractures

  • Continue exercises as above.
  • Limit supination and pronation.
  • Change the long-arm cast to a short-arm cast (bridging callus indicates stability).

Following ORIF surgery

  • Advance therapy with gentle AROM of the wrist and gentle opposition and flexion/extension exercises to the thumb.
  • Continue elbow and shoulder exercises.
  • Remove the short-arm cast at 6 weeks if the fracture appears to be radiographically healed.
  • Use a wrist splint for protection.

Rehabilitation considerations in 8-12 weeks[6]

For casted fractures

  • Remove the short-arm cast at 10-12 weeks if the fracture appears to be radiographically and clinically healed.
  • A wrist splint may be used for protection

For casted fractures and following ORIF

  • Consider pulsed electrical stimulation if no evidence of union is noted by 8 weeks, and consider surgery with bone grafting if progress is not observed by 12-14 weeks
  • Advance therapy with gentle AROM of the wrist and with thumb exercises
  • Begin grip strengthening with the use of silicone putty at 10 weeks
  • Advance as tolerated to progressive resistive exercises (PREs)

Additional Resources

Clinical Bottom Line

The scaphoid bone is the most commonly fractured carpal bone. Stress on the scaphoid, due to a forceful motion, may have a fracture as result (mostly due to a fall on outstretched arm). The pain, which often is mild, is aggravated by pinching and gripping. The diagnoses can be differentiated by the location of tenderness, pain with certain maneuvers, and radiographic abnormalities. The length of immobilization affects negatively the outcomes. Internal fixation provided a satisfactory outcome for control of instability and a early functional recovery of the wrist. There are different fractures types classified by Herbert and Fisher's system. To recognize these different fracture types, it is essential that adequate radiographs are taken of both wrists.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Gutierrez G, Office management of scaphoid fractures. Phys Sports Med. 1996;24:60–70. Level of evidence: 5
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 T. Grant Phillips et al, Diagnosis and Management of Scaphoid Fractures, Am Fam Physician. 2004 Sep 1;70(5):879-884. Level of evidence: 5
  3. 3.0 3.1 3.2 Greene WB, Essentials of musculoskeletal care. 2d ed. Rosemont, Ill.: American Academy of Orthopaedic Surgeons, 2001:252–4. Level of evidence: 5
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Hayat Z, Varacallo M. Scaphoid Wrist Fracture. InStatPearls [Internet] 2019 Jan 4. StatPearls Publishing.Available from:https://www.ncbi.nlm.nih.gov/books/NBK536907/ (last accessed 23.3.2020)
  5. Kawamura,K. & Chung, C.C. (2008). Treatment of Scaphoid Fractures and Nonunions. J Hand Surg Am. 2008 Jul-Aug; 33(6): 988–997.  doi: 10.1016/j.jhsa.2008.04.026
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Scott R. Laker et all, Scaphoid injury (Epidemiology), Medspace. 2015, 6 April. Level of evicence:5
  7. 7.0 7.1 7.2 Mc Dermid, Patient Rating of Wrist Pain and Disability: A Reliable and Valid Measurement Tool, 1998. Levels of evidence: 2A
  8. 8.0 8.1 Bill Schloss Gillian Lieberman, MD, Scaphoid fractures, Harvard Medical School, Year Harvard Medical School, Year-IV. Januari 2001: pg 3. Level of evicence: 5
  9. 9.0 9.1 A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture, skeletal radiology, 1998, level of evidence: 3B
  10. 10.0 10.1 Moran C. G., Combining the Clinical Signs Improves Diagnosis of Scaphoid Fractures A prospective study with follow-up, 2004, level of evidence: 3B
  11. Grewal, Ruby, Nina Suh, and Joy C. MacDermid. "Is casting for non-displaced simple scaphoid waist fracture effective? A CT based assessment of union." The open orthopaedics journal 10 (2016): 431. (level of evidence 2B)
  12. Schädel-Höpfner, M., et al. "Acute scaphoid fractures: Management under consideration of the new S3-level guideline." Der Orthopade 45.11 (2016): 945-950. (level of evidence 5)