Scapholunate ligament injury

What is Scapholunate ligament injury?

Scapholunate ligament (SLL) is a C shaped ligament of the wrist that joins two bones scaphoid and lunate (carpal bones, bones of the wrist). It plays an important role in maintaining the stability of the wrist joint. Scapholunate ligament injury is typically caused by a fall on an outstretched hand from a height or high injury trauma as in sports or motorcycle accidents.

Scapholunate ligament injuries are commonly missed or dismissed as sprain.  Injury in the scapholunate ligament is associated with the altered biomechanics and wrist instability – DISI (dorsal intercalated segmental instability, a type of carpal instability). Injury to scapho-lunate ligament happens in 10-30 % of intra-articular distal radius fractures (wrist fractures). Degenerative tears are also common in 50 % of old people over the age of 80 years.

 

What are the symptoms of Scapholunate ligament injury?

Scapholunate ligament injury causes pain and stiffness in the wrist. Clicking and clunking with movement of the wrist is noticed. Swelling is present in most of the cases which are located in the centre of the back of the wrist.  You may feel a reduction in the flexibility of the wrist.  Weakness or instability of the wrist is also common. In chronic scapholunate ligament injuries the instability progresses to wrist arthritis (SLAC wrist – Scapho Lunate Advanced Collapse) associated with pain, swelling and stiffness in the wrist.

 

How is it diagnosed?

Your orthopaedic surgeon will get history of injury, examine your wrist and will ask you for an X-ray. In most cases further investigations (MRI/CT scan) are essential to confirm the diagnosis and plan for management. In selected cases with scapholunate widening, your surgeon may ask for x-ray of opposite wrist to rule out non-pathological wrists.

 

What happens if nothing is done?

If it is left untreated, there is constant wear and tear of the wrist joint that predictably progress over the time of 5- 10 years to arthritis. The pattern of arthritis is called scapholunate advanced collapse (SLAC or SNAC) and is associated with pain swelling and stiffness of wrist.

 

How is it treated?

Depending on the severity of the scapholunate ligament injury, this can be treated either with surgery or non-operative treatment. In patients with partial injury and no widening of scapholunate gap, this can be treated by rest, painkillers, splints and hand therapy.

 Surgery is indicated in

  • Acute complete tear of scapholunate ligament
  • Carpal malalignment
  • Chronic injury but reducible ligament (< 18 months)
  • Irreducible ligament over 18 months
  • Associated carpal bone fractures

 

What are the non-operative treatments?

The conservative treatment or non-operative treatment includes the following-

  • Cast/Splint- for 6 weeks, Ice application- you can apply ice to the affected area for 20-30 minutes several times a day to reduce swelling and pain.
  • Medicines- you can take painkillers such as paracetamol or codeine and anti-inflammatory medicines like ibuprofen and aspirin to reduce pain and swelling respectively.
  • Hand therapy- focussed hand therapy is recommended for the injury to the scapholunate ligament. This therapy can strengthen muscles and help to regain full function. It also helps to avoid stiffness and weakness of the wrist. It should be done under the supervision of your surgeon and hand therapists.

 

What does the operation involve?

The main aim of the surgery is to repair and reconstruct the ligament and improve the stability of the scaphoid.

  • The operation is performed as a day case, an incision or cut is made on the skin over the affected area to reconnect the ligament to the bone.
  • The ligament is repaired and reconstructed with tendon graft using free needle sutures or bone anchor sutures. Pins and wires are also used for correcting the deformity. In selected cases the wires are temporarily left (for 6 weeks) in the wrist to allow the carpal bones to heal in the correct position.
  • The skin is stitched using absorbable sutures and a splint or cast is applied. The surgical time is usually 1-2hrs and the majority of the patients go home 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, in some cases – removal of pins and x-rays.
  • 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 assessment. The duration may increase or decrease based on the complexity of injury and method of fixation.

 

Are there any risks?

  • Wound infections < 1%
  • Injury to nerves, blood vessels and tendons
  • Scar tenderness.
  • SLAC wrist (Scaphoid Lunate Advanced Collapse)
  • Stiffness
  • Reduced grip strength
  • Pain, stiffness and fatigue after surgery
  • 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 overall outcome of the surgery is good and most patients regain good function back in their wrist. The outcome following this surgery depends on grade and severity of the injury, associated injuries, duration between injury and surgery, treatment involved and adherence to physiotherapy.

 

When can I return to driving and work?

The scapholunate ligament may take 8- 12 weeks to heal. 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, chronicity and the treatment modality.  Your physician will be able to advise you.

Scapholunate ligament injury

  1. Scapholunate ligament injury leading to widening of the interval between scaphoid and lunate (Terry Thomas sign).
  2. Repair using tendon and anchors/

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