A finger sprain refers to significant stretching or tearing of the soft tissues around the joint. Ligaments are strong bands of tissue that connect bones to each other. Finger joints have a pair of ligaments of the either side and a strong volar plate on the palm (volar) side of the finger. Joints are further reinforced and stabilised by the surrounding capsule, tough, gristle-like wrapping around the joint. Together, ligaments and capsule form a tough, yet elastic capsulo-ligamentous layer whose integrity is vital for finger mobility and strength. Injuries to the joint that connects the first and second phalanx (the small bones of the fingers) known as the proximal interphalangeal joint are particularly at risk of leading to late finger deformities because of late diagnosis and complex and sophisticated joint anatomy.
Sprain usually results from a blow to the finger causing the joint to bend too much or in the wrong direction. This often occurs during athletic activity, but even trivial accidents and pursuits can result in awkward pull. As capsulo-ligamentous layer around the joint typically has scarce blood supply, its injuries lead to a rather slow recovery, especially if not recognised and treated early. Furthermore, those ligaments have a propensity to shorten as they heal which can result in long term stiffness.
Picture 1 shows simplified anatomy of the soft tissue arrangement around the proximal inter-phalangeal joint. The ligament called ‘the volar plate’ (coloured blue) is positioned on the palm, flexor side of the joint and its shrinkage (contracture) is one of the most important causes of finger deformity. Other small components of ligaments on each side of the finger (coloured green) are often involved too. When the injury is diagnosed early, it is possible to straigthen the finger and keep these structures stretched. If on the other hand, these ligaments are left on their own after sprains, the joint might be pulled in flexion and contracture likely to worsen over the next few months, sometimes even becoming irreversible. Such outcome is very difficult to treat, even operatively. Surgery aims to straightened the finger by dividing the shortened volar plate (Picture 2) which then allows stretching of the joint and its surrounding soft tissues. Outcome is not entirely predictable because of new scarring laid down in response to surgery, but this is often the only solution to chronicly bent joint. A lot of postoperative rehabilitation and physiotherapy is necessary to support operative steps.
It is much easier to prevent contracture then treat it. Early diagnosis is essential. Picture 3 illustrates truly advanced (luckily rare) deformity due to unrecognised capsulo-ligamentous injury of the proximal inter-phalangeal joint.
Majority of finger sprains are self-limiting and will settle spontaneously in 2-3 weeks.
Symptoms include pain, swelling and stiffness. With active input from the beginning, finger sprains can be managed very successfully by splintage and specific finger exercises. On the contrary, if not recognised early, sprains recover very slowly and can lead to progressive bending of the finger i.e. contracture (finger cannot be straighten properly). This happens because of scarring and shrinking of ligaments which start to pull the joint inwards.
If the force imposed upon finger was not just trivial, capsulo-ligamentous injury should be suspected. This is particularly the case if finger is imminently painful, swollen and bruised after an accident. Common scenario is that a patient does seek help soon after injury. X-rays are likely to be ordered and once the fracture is excluded (which is commonly the case), patient is reassured and discharged without active treatment. Ongoing pain, swelling and stiffness might prompt him/her to seek secondary help much later, often weeks and months following injury. Occasionally, X-rays may show an avulsion of a tiny piece of bone which unmistakably points to the tearing of the ligament at point of its insertion into the bone. Management is usually the same, but abnormal X-ray often speed up referral process.
Finger sprains are graded according to their severity:
Stretching and micro-tearing of ligament tissue, but the joint remains stable
Partial tearing of ligament tissue with mild instability of the joint
In case of minor sprain of the finger, consider the following at home:
- Rest – take a break from the activity that caused the pain
- Compression – apply an elastic compression bandage which reduces swelling and provides comfort
- Elevation – Keep the injured leg raised for the first 24 hours, including during sleep.
- Medication – take anti-inflammatory medications to relieve pain
If you play sports, you may need to tape your finger to the neighboring finger when returning to play. This is the simplest, comforting way of protecting injured finger and encourage its mobility early.
Active, specialist input most commonly involves, splintage of the joint in adequate position, controlled exercises and tissue stretching. These measures might appear simple, but they should be conducted in a knowledgeable way. The most optimal position for recovery varies between different finger joints due to variations in their anatomy. Finger should be mobilised early to control swelling and stretch the capsule, but not overzealously to compromise ligament healing. So balance between rest and mobility is what most therapists aim for in order to preserve finger function in the long term.
Physiotherapy can be tedious, but compliance and discipline predictably leads to good results and avoids the need for surgery.
Surgery is rare, but may be required if there is:
- Complete tearing of the ligament
- Avulsion fracture i.e. a large piece of bone has broken off and is being displaced by the ligament pull
- Old, fixed flexion deformity of the joint which failed to improve despite prolonged physiotherapy and other measures (see above)
If you have any concerns following your surgery please contact:
Ashtead 01372 221 442; St Anthony’s 020 8337 6691; Parkside 020 8971 8000
Picture 3 - old and advanced finger deformity following unrecognised sprain of the proximal inter-phalangeal joint ligaments