Conditions And Treatments
The foot and ankle is an incredible structure that transmits the energy of the body through the ground so as to allow forward progression of the body. The forces transmitted through the foot, upon each step, are greater than the weight of your body especially when running. In the majority of cases these forces are transmitted without any problems. However problems can occur that not only affect the foot and ankle but can produce problems further up the body.
Problems can be associated with acute injury e.g. an ankle sprain, stubbing a toe etc. but can also be due to hereditary conditions such as bunion deformity. Foot and ankle problems are varied and can be complex in nature, but often respond to a period of conservative (non-surgical i.e. ultrasound, shockwave therapy, physiotherapy etc.) and medical care e.g. steroid injections, it is only when these treatments fail that surgery should be considered.
The big toe joint is the joint most commonly affected within the foot. The two most common conditions are bunions and arthritis: hallux limitus (hallux; big toe, limitus; reduced motion).
Bunion deformities are the most commonly presenting problem affecting the foot. A bunion is characterised by the 1st metatarsal, the long bone of the foot, moving towards the inside of the foot with the big toe moving in the opposite direction. This leads to prominence on the inside of the foot which can produce irritation from footwear. The deformity can also produce pain due to the big toe joint functioning in a poor position.
Bunion deformities are hereditary conditions, but can skip generations so your parents may or may not have developed the deformity and this holds for your grandparents and future generations. Tight or ill-fitting footwear does not produce a bunion, however if you have a pre-existing bunion deformity shoes that push the big toe further over can accelerate its progression.
Bunion deformities are progressive deformities and therefore increase in size over time, but how quickly they progress and whether they are actually ever going to produce any problems is difficult to predict. Problems include pain from the big toe joint itself, pressure from footwear, possible arch instability, pain at the joint next to the big toe joint and hammer toe deformities. When pain arises from the joint next to the big toe joint, 2nd metatarsophalangeal (met-a-tar-so-fa-lan-ge-al joint) (MTPJ) it is termed capsulitis . This problem occurs when the 1st metatarsal has drifted so far over, towards the inside of the foot, the weight that should be borne beneath the big toe joint is reduced and the pressure is transferred to the smaller more delicate 2nd MTPJ. This pressure produces injury to the joint capsule and a structure called the plantar plate. The plantar plate provides stability by preventing the toe rising up so when it is damaged this stability is lost and pain and a hammer toe develops. If this problem is associated with a bunion deformity treatment is required to reduce the bunion and redistribute the pressure beneath the big toe joint as well as reduce the hammer toe and repair the plantar plate.
There are many different treatments available to manage bunions and their associated problems and can include non-surgical and surgical treatments. Surgical procedures for bunion deformities are tailored to the size of the deformity, associated factors such as increased mobility of the foot and your requirements and expectations as a patient.
The majority of the operations to correct a bunion deformity involve realigning the bones followed by holding the bones in position whilst they heal and is achieved through fixation such as screws and plates. This fixation is internal and very rarely requires removal and serves its purpose until the bone has healed. With modern fixation methods it is often the case that plaster cast immobilisation and periods of non-weight bearing are not required, thereby allowing for a quicker return to normal activity.
Hallux (big toe) limitus (limited) is a wear and tear arthritic condition of the big toe joint. It is the second most common condition affecting the foot and ankle and can produce pain and limit a persons’ activity. Many factors have been implicated in the development of hallux limitus but the most common cause is trauma to the big toe joint. This trauma is through either stubbing the toe or by dropping a weight onto the joint. This trauma damages the articular cartilage, the shiny and smooth material that is on the end of bones and allows the bones to move in an unrestricted manner.
This damage produces cracks within the cartilage and allows the joint to seep under the cartilage and cause it to come away. This reduces the thickness of the cartilage and allows for the two bones of the joint to become compressed which produces further wear on the cartilage and bone, cartilage defects (osteochondral defects).
If this process continues eventually all of the articular cartilage can wear away to expose the underlying bone and further increase pain levels. Hallux limitus is characterised by enlargement of the big toe joint due to new bone formation to limit motion of the joint and reduce pain, stiffness of the joint and pain.
The sesamoid bones are two pea shaped bones which are situated on the underside of the big toe joint and protect the underside of the joint as well as increasing the strength of the downward motion of the joint.
Due to the position of the sesamoids a lot of force is placed through them when we walk or run. On occasion the sesamoids bone can become injured. The term sesamoiditis (inflammation of the sesamoids is a broad term which covers a number of pathologies to include: fracture, avascular necrosis (interruption to the blood supply of a bone); this can cause collapse of the bone and arthritic changes, arthritis and non-specific inflammation / stress.
The seamoids are also affected in a Turf Toe (link to sports injuries and TURF TOE) injury, this is where there is disruption of the ligaments supporting the sesamoids. Sesamoid problems can also occur in certain foot types to include a high arched, cavoid, type foot.
Management of sesamoid problems is dependent on the cause of the problem but in the first stages includes rest, activity modification and reduced weight-bearing. Investigations can range from x-ray, ultrasound scans to MRI
Toe deformities can arise through a number of different reasons to include the position / biomechanics (the way the foot functions) of the foot, disease processes such as rheumatoid arthritis, neurological condition, age (as we get older we are more likely to develop lesser toe deformities), trauma (capsulitis / plantar plate injury) and secondary to bunion deformities.
There are many different types of digital deformities but the most common types are:
A hammer toe is where there is extension of the toe at the ball of the foot joint (metatarsophalanageal (met-a-tar-so-fa-lan-g-al joint)) which is reducible, can be straightened out with a bend of the joint of the toe in the middle, this can be either flexible or inflexible.
A mallet toe is where the tip of the toe is in a downward position, impacts the ground and produces a corn or thickening of the nail.
Clawed toes are a more complex deformity where the toe is sitting up in the air at the ball of the foot and cannot be reduced to a corrected position, the joints of the toe are also in a fixed position and point towards the ground. To correct this type of deformity surgery is required on the toe and often the metatarsal (the ones of forefoot).
Other toe deformities include windswept toes. This is where the toes move towards the inside or outside of the foot and crossover toes where on toe over or under laps another toe.
Treatment of toe deformities can range from alteration of footwear, padding, toe spacers and surgery.
Surgery generally falls into two categories arthroplasty (new joint formation) which involves removing a piece of bone to reduce any contracture on the joint and to allow the toe to sit in a better position and arthrodesis (fusion of the joint). Fusion of the toe produces a rigid toe and reduces the risk of any recurrence and is indicated for certain digital deformities especially those associated with neuromuscular conditions.
For toe fusions an internal fixation device sits between the two bones so as to stabilise the toes and allow for the bones to heal together thereby producing the fusion. The implant used in toe fusions is the smart toe, an internal fixation device allows for a more practical recovery as there are no wires protruding from the end of the toe for six weeks.
Metatarsalgia is a term used to cover a number of conditions that can affect the ball of the foot, it is not a diagnosis.
Capsulitis (cap-su-li-tis) is a common condition affecting the ball of the foot with the 2nd metatarsophalangeal joint being the most commonly affected. This condition is often described as if “walking around with a pebble in my shoe” and significant pain being experienced when treading on the knobbly paving stones around traffic lights. There are a number of different reasons as to why this problem occurs to include overuse injuries associated with running and high impact activities, bunion deformities, long or prominent metatarsals and inflammatory conditions.
Often this condition is progressive and if not managed in a timely manner and effectively can result in a toe deformity such as a hammered or mallet toe.
Treatment for this condition includes alteration of activity, footwear, stretching exercises as tightness in the muscles of the leg can produce overload of the foot due to a lack of flexibility, insoles and as a last resort surgery.
A neuroma is a condition where a nerve enlarges and produce pain which is often experienced as shooting and burning. The condition is benign (non-cancerous) and very rarely does this change.
In the foot the most common neuroma is a Morton’s neuroma and is present between the third and fourth metatarsal heads (ball of the foot) and sends nerve pain into the third and fourth toes. Neuromas can develop between the other metatarsal heads and affected the associated toes but a Morton’s neuroma is the most common.
Treatment for a neuroma includes stretching exercises, footwear alteration, steroid injections and surgery.
Depending on the size of the neuroma minimally invasive surgery may be appropriate. http://www.osteomed.com/SBO_Lower/KobyGard.aspx
A Tailor’s bunion is a bunion deformity affecting the fifth metatarsal and toe joint. The deformity is the same as a bunion but in reverse. The fifth metatarsal moves towards the outside of the foot and produces problems with rubbing against the outside of the shoe.
Tailor’s bunions can be managed by wearing a roomy shoe but if this fails to manage the problem surgery may be required.
Corn / Callus / Hard skin of the ball of the foot
Skin lesions at the ball of the foot are common and develop due to abnormal pressure or shear when walking. The problem can be isolated to one area of the foot, often beneath a metatarsal head or affect the whole area of the forefoot. Skin lesions can also develop in conditions such as bunion, tailor’s bunion and hallux limitus (stiff big toe joint). In the case of these deformities skin lesions develop due to altered mechanics of the foot leading to transfer pressure.
Treatment of skin lesions can vary depending on whether it is localised to one area or the whole of the forefoot.
Treatment can include stretching exercises, insoles, footwear alteration, surgery to manage any associated structural deformities e.g. a bunion and shortening or elevating prominent metatarsal heads or in certain cases where conservative care has failed and there is still tightness of the calf muscle complex lengthening of the muscle (gastrocnemius recession).
Osteochondrosis: Freiburg’s disease / Avascular Necrosis
Osteochondrosis is a condition that affects bones where the growth centre is still active. In the forefoot the lesser metatarsal with the second metatarsal being the most commonly affected. In adults and when the growth plates have ceased and amalgamated with the rest of the bone the condition is termed avascular necrosis. Both conditions involve an interruption to the blood supply to the bone which is often due to trauma.
The most commonly affected metatarsal is the second metatarsal and in children the condition is called Freiburg’s disease. This condition produces pain during and after activity and may be associated with swelling and redness of the joint.
Management of this condition should be rapid as further trauma produces long term damage and arthritic changes into the future.
Arthritic Metatarsophalangeal Joint
Arthritis of the lesser toes, excluding the big toe, most commonly affects the second metatarsophalangeal joint. Reasons behind the development of arthritis include trauma, healed Freiburg’s disease and inflammatory joint disease to include rheumatoid arthritis.
Management of this condition can include steroid injections, alteration of footwear and activity, insoles and surgery to include removal of bony outgrowth and remodelling of the joint to joint replacement. There are a number of joint replacements and the indications for each of these are influenced by a person’s age and activity levels. Joint replacments for this condition include the Cartiva implant.
Fractures of the foot can be caused by an acute injury such as sudden traumatic incident or can occur over time. Fractures that occur over time are termed stress fractures and patient often experience pain when walking and swelling. Pain is eased by rest but starts again when walking etc. Up to four weeks after the injury a stress fracture may not be apparent on x-ray and the best investigation is an MRI as the initial changes are often subtle. Management of stress fractures is often conservative management to include rest and splinting of the foot. If left untreated the pain and immobility can continue and may worsen with pain developing elsewhere in the foot as your walking pattern is altered which creates greater stress elsewhere in the foot and pain.