What is a hook of hamate fracture?
A hook of hamate fracture is the term used for a break in the hook portion of the hamate bone. The hamate bone is one of eight carpal bones that conjoin and create your wrist. These small carpal bones form two rows of four, the cube-like bones articulate on one side with the radius and ulna bones of the forearm and on the other side with the metacarpal bones that lead to the thumb and fingers. The hamate bone sits on the outside of the wrist under the pinkie finger; the hook portion of the bone also known as the hamulus is a small boney protuberance in the shape of a hook, demonstrated in the picture below.
Why and when do hook of hamate fractures happen?
Hook of hamate fractures most commonly occur from repetitive micro-trauma during certain sports. Sports associated with these fractures are those that involve a club, racket or stick. The position of the stick, racket or bat in the hand means that it rests up against the hook of the hamate meaning that the hook takes the full force of a hit or swing. It is more common that repetitive sporting trauma causes a stress fracture over the hook, which differs from a fracture as it is only a partial break in the bone. Forces large enough can cause a complete break but this is normally seen when someone has fallen onto their wrists, swung a golf club against a hard surface like the ground or had their hand compressed between two heavy weights.
What does a hook of hamate fracture feel like?
A hook of hamate fracture causes a very intense immediate sharp pain around the fracture site along the side of the wrist/hand under the pinkie finger. The sharp pain often radiates up into the fingers and across into the rest of the wrist and palm of the hand. The fracture is often accompanied by swelling and bruising in the wrist which will feel tender to touch. The pain levels will be aggravated by most hand or wrist movements this makes gripping with the effected hand excruciating. The intense pain after a break will last for several hours, when the bone starts to heal there will be a dull continuous ache from the swelling and healing process that will last for over a month. During the healing process the bone is trying to knit together and re-unite, this stage can be quite painful and it is very important to rest through this stage to ensure that the bone reconnects properly. The soft tissue surrounding the fracture also starts to form scar tissue to bind everything together allowing the structure to try and restore its original state and function. Occasional stress fractures of the hook can be asymptomatic and the individual will be unaware of the injury.
How are hook of hamate fractures diagnosed?
Patients may be taken to A&E and a full examination will be done to rule out any additional injuries or complications like nerve damage, as the ulnar nerve and artery pass very closely to the hook. Your doctor will order an X-ray of the wrist and hand to confirm the diagnosis and identify the exact location and extent of the fracture. Occasionally if the extent of the fracture isn’t fully visible on an X-ray then an MRI or a CT scan will be orderedas this will give a more detailed view of the fractured site although this is rarely needed for a hook of hamate fracture. Doctors may also use an MRI scan to assess whether the pain felt after trauma is coming from injury to the wrist and hand muscles, ligaments or joint capsules and not indeed from a fracture. The occurrence of a fracture from mild trauma may prompt doctors to investigate for any underlying bone weakening conditions like osteoporosis.
What treatment options are available for hook of hamate fractures?
The treatment options and healing times for hook of hamate fractures vary depending on the type and severity of the fracture and also on the complications from any additional injuries like nerve or arterial damage. In most cases doctors will recommend conservative treatment using a hand splint or cast to immobilise, reinforce and stabilise the fracture for over 4 weeks until it is well healed. Occasionally if the fracture is diagnosed late and the fractured bone has fragmented away from the hamate then surgical removal of the bone fragment is the best option. This again is followed up by at least four weeks immobilisation in a cast or splint. Patients will initially have to rest and avoid using the effected hand whilst recovering. The doctor will most likely prescribe anti-inflammatory medication and painkillers for pain relief and to reduce any swelling. A hook of hamate fracture can take anything from 4 -6 weeks to heal if not longer for more severe breaks. Patients will be referred through to a physiotherapist who will provide exercises to strengthen the hand to aid the healing process. Fluctuating pain levels will be experienced throughout the healing process however most of the discomfort towards the end of the healing process comes from stiffness levels caused by long term immobility. The rehabilitation exercises as well as massage and some manipulative therapies can aid in recovering your wrist and hand strength and flexibility. There are also great products to use at home to rebuild grip and hand strength such as therapeutic putty and therapy balls.
