Scaphoid fractures including non-union

What are Scaphoid fractures?

The scaphoid fracture is discontinuation of integrity or break of the scaphoid bone. The scaphoid bone is a twisted bean shaped carpal bone that lies on the side of the wrist above the radius towards the thumb. This bone plays an important role in stability, biomechanics and the movement of the wrist joint.  Most fractures occur in the middle of the bone and are usually caused by a fall onto an outstretched hand where your weight lands on the wrist. It can also happen due to motor vehicle accidents and during sports activities.

Scaphoid fractures account for 15 % of the acute injuries of the wrist. The site of fracture in the scaphoid bone is wrist (65%), proximal third (25%) and distal third (10%). The distal part of the scaphoid bone is commonly fractured in kids. Non-union of bone fragments in scaphoid fracture occur in 5- 10 % cases without displacement which may go higher in displaced fractures.

 

Why we need to keep a close eye on scaphoid fracture?

Scaphoid bone has a unique blood supply, unlike most other bones with blood supply that comes at both ends, scaphoid blood supply is only through distal part of the bone. As most fractures are in the proximal part of the bone, there is an increased risk of delayed union, non-union and chances of part of the scaphoid becoming dead (avascular necrosis).

 

What are the symptoms of Scaphoid fractures?

Pain, tenderness, bruising, and swelling are the common symptoms of the scaphoid fractures which are located at the anatomical snuff box on the thumb side of the wrist. Pain gets worse when you try to move your wrist or thumb especially during pinching or grasping an object. In chronic cases the patients will also have restriction of movements in addition to the thumb sided wrist pain. In some, the arthritis might have set in at the time of presentation (SNAC – Scaphoid Non-union Advanced Collapse).

 

How is it diagnosed?

Your orthopaedic surgeon will discuss with you, your medical history, history of the injury and your symptoms. He will examine your wrist to check tenderness, bruising and range of motion of your wrist. He may ask you for X-rays to find out the location and extent of the fracture. CT scan and/or MRI scan are needed to assess the blood supply of the bone, deformity and to plan the treatment.

 

What happens if nothing is done?

If it is left untreated, the fractured bone fragments may not unite well, and remain unhealed and painful. This condition is also known as scaphoid non-union. It can lead to arthritis (SNAC wrist – Scaphoid Non-union Advanced Collapse) in the wrist with painful limited movement of the wrist.

 

How is it treated?

Both surgical and conservative treatments can resolve scaphoid fracture. The decision to select treatment methods depends on the location and displacement of the fracture and the duration of the injury. Conservative treatment is first line of treatment in undisplaced and minimally displaced waist fracture.  It involves rest, plaster, painkillers and hand therapy.

Surgery is indicated in –

  • Fractures in its proximal pole
  • Displacement > 2mm
  • Delayed/nonunion
  • Humpback deformity
  • Comminuted fractures
  • Unstable fractures (oblique or vertical)
  • Associated with ligamentous injuries (perilunate dislocation)

 

What are the non-operative treatments?

If the fracture in the scaphoid bone is near the thumb, then, it heals quickly because of sufficient blood supply in few weeks.  But fracture near the forearm takes much time to heal as the blood supply to this area is less.  The non-operative treatment involves

  • Rest- you should rest your hand and avoid those activities that provoke pain like lifting or carrying heavy objects, throwing anything, contact sports, climbing trees, etc.
  • Cast immobilisation- your surgeon will give you a cast to wear for 6 -10 weeks as immobilization can help to keep the bones in position and help in the proper healing of the broken bones without a new injury.
  • Medicines-painkillers such paracetamol can be taken for the relief of pain. Anti-inflammatory drugs such as aspirin and ibuprofen can be taken to control inflammation and pain. Anti-inflammatory drugs should be taken cautiously as it could delay fracture healing, affect your stomach and kidneys.
  • Hand therapy- it is started with gentle exercises for hand and fingers to regain strength and prevent stiffness due to immobilisation. It is followed by strengthening exercises. It should be done under the guidance of your surgeon based on the radiographic union of the fracture.

 

What does the operation involve?

The main purpose of surgery is to stabilization and realignment of the fractured bone fragments into their original position. It can be done by percutaneous or open surgery.

  • The surgery is conducted as a day case under general anaesthesia. The skin is cut in the affected site to realign the bone fragments. The number of cuts on the skin depends upon the surgery technique adopted.
  • The bone fragments are repositioned together with pins or screws. In some cases with multiple fracture fragments, bone substitutes are used to accelerate healing and to bridge the gap. Bone grafts can also be used to stimulate bone production and healing. The bone graft may be derived from forearm bone of the same arm or from hip.
  • The cuts on the skin are then stitched with absorbable sutures. A sling or plaster cast is applied to allow healing by protecting it from injury and stress. The operation takes one to two hours and a majority of the patients are discharged on the same day.

 

What happens after surgery?

  • The local anaesthetic wears off 4-10 hrs after surgery; patients are encouraged to start taking painkillers before the pain starts i.e. on return home and for at least 48 hours from there. This way most of our patients report little or any pain.
  • You have to keep your hand and wrist elevated (above the level of your heart) and keep moving your fingers, elbow and shoulder to maintain the flexibility and prevent stiffness of the joints.
  • Your wrist is rested in a half cast for 10-14 days followed by full cast for another 4 weeks to protect it from injury and allow proper healing. At 2 weeks, the wound is checked before application of full cast and referred to hand therapy.
  • You are reviewed again after the period of six weeks for removal of plaster and x-rays, in selected cases the plaster immobilisation could increase by another 4 weeks.
  • The wound should be massaged using moisturising cream by the patient 3 times a day for 3 months once the wound is well healed. This reduces the scar sensitivity and scar-related complications (tenderness; helps scar to mature).
  • You could start a gentle range of movement (ROM) exercises at 6 weeks and progress to more strenuous activities (swimming, driving, lightweights in gym etc) around 12 weeks. This will be guided by your surgeon and is based on radiographic (X-ray) and clinical union of the fracture. The duration may increase or decrease based on the personality of fracture, quality of bone and method of fixation.

 

Are there any risks?

  • Wound infections < 1%
  • Injury to nerves, blood vessels and tendons
  • Scar tenderness.
  • Non-union
  • SNAC wrist (scaphoid non union advanced collapse)
  • Avascular necrosis
  • Stiffness
  • Chronic Regional Pain Syndrome “CRPS”.
  • Any surgery can end up with rare complications and leave a patient worse than before surgery and is rare in this surgery

 

What are the results of the operation?

The results of the operation in scaphoid fractures are excellent with union rate up to 90-95% with minimal complications. Most patients regain their normal range of motion and function of the wrist. The outcome is more predictable under the author’s experiences.

 

When can I return to driving and work?

Scaphoid fractures may take more time to recover as it heals slowly. You can get back to work in 2-4 weeks if you have a desk job, however might take upto 3 months if your job involves physical work. Regarding return to contact sports, it usually takes 3-6 months and depends on the severity of injury.  You should be able to resume driving in 6-12 weeks. The above time line could vary based on the severity of injury and the treatment modality.  Your physician will be able to advise you.

Scaphoid fractures including non-union_1

  1. Scaphoid fractures proximal pole with sclerotic edges (above) and waist fracture with cyst formation (below)
  2. Fixation with different types of screws

Scaphoid fractures including non-union_2

Non-union treated with bone graft taken from distal radius.

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