Capsulitis / Synovitis
Joints are held in place and supported by ligaments and an outer
covering known as the joint capsule. The inner layer of the joint
capsule is called the synovial membrane and this produces the oily
liquid (synovial fluid) that lubricates the joint. Inflammation of
the joint capsule can be termed capsulitis or synovitis. Synovitis
is generally accompanied by an increased production of synovial
fluid causing some swelling of the joint.
Whilst this can occur at any joint it often occurs at the joint
at the base of the second or third toes and the ball of your foot
(metatarsophalangeal joints). This section will concentrate on
What causes capsulitis/synovitis?
This is generally due to overload from an associated deformity,
poor foot function or inappropriate footwear (e.g. high heels).
However, certain medical conditions (e.g. rheumatoid arthritis,
osteoarthritis) can predispose to inflammation within the
The second and third metatarsals (the long bones that form the
joints with the toes of the ball of the foot) are the most stable
in the foot. As we walk, the other metatarsals are mobile to allow
the foot to adapt to uneven surfaces. If these metatarsals are not
loading properly or the second and third metatarsals are either
long or prominent, then overload and inflammation of the joint can
Are women more likely to get the problem?
It is more common in women as they tend to wear tighter,
narrower shoes with increased heel height. These shoes place a lot
of pressure onto the joints and predispose to deformity. It is
common for patients to wear shoes that are too small and this can
aggravate the problem. In a study we have performed, 95% of
patients were in the wrong size shoes, most of which were too
Will it get worse?
It is extremely common for people to develop discomfort at these
joints and ignore it in the hope that it will settle. What commonly
happens is that the pain slowly gets worse and the toes start to
bend and become prominent. Eventually, the pain settles but the toe
sits up in the air causing a problem in shoes. This is because the
long-term inflammation and damage to the joint capsule results in a
rupture. This destabilises the toe and it becomes deformed and
prominent. Whilst the pain settles, the toe will cause discomfort
in shoes, which is much harder to treat.
What are the common symptoms?
- Pain under the central ball of the foot directly under the bone
- Redness around the joint
- Swelling around the joint
- Deformity of the toe
- Difficulty in shoes
- Difficulty with walking
- Stiffness in the joint
- The swelling in the joint can irritate the nerve giving
symptoms similar to a
How is it recognised?
Clinical examination and a detailed history allow diagnosis.
X-rays help to evaluate the extent of the deformity and the degree
of arthritis / damage within the joint. Injecting a dye which can
be seen on x-ray (radio opaque) into the joint can help to identify
damage to the capsule. This is known as an arthrogram. An
ultrasound or MRI scan can help to diagnose soft tissue problems
such as inflammation.
What can I do to reduce the pain?
There are several things that you can do to try and relieve your
- Wear good fitting shoes
- Avoid high heels
- Wear a protective pad
- Hot or cold packs may help
- See a podiatrist
What will a podiatrist do?
If simple measures do not reduce your symptoms, there are other
- Advise appropriate shoes
- Advise exercises
- Advise on how you can strap/splint the toe into a corrected
- Consider prescribing orthotics with deflective padding
- Refer for postural manipulation / control where
- Consider a cortisone injection
- Advise on surgery
The way in which your foot loads during walking can place
increased stress on . Special shoe inserts (orthotics) can
help to control foot movement. Whilst these are unlikely to resolve
established deformity, orthoses with extra padding beneath the ball
of the foot are often necessary for this condition.
A cortisone injection can relieve discomfort. However, if
walking and trauma continues, this can result in rupture of the
joint capsule causing a fixed toe deformity. The use of a period of
immobilisation following the injection minimises this risk.
Some patients have reduced motion in the foot which can be
related to their postural control of the whole leg. In these
instances, physiotherapy / osteopathy / chiropractic input may be
Will this cure the problem?
If there is an underlying deformity, this will not be cured.
However, the contributing factors and therefore symptoms can be
What will happen if I leave this alone?
There is a window of opportunity to address the overload before
the joint capsule ruptures. If this problem is not treated, it is
common for the pain to get worse until rupture and toe deformity
If symptoms persist, or deformity results, surgery may be
How can I cure the deformity?
Surgery is generally required.
How does the operation correct the problem?
If there is a bunion or hammer toe deformity pre-disposing to
overload of the joint, these will often require correction (see
If there is evidence that the metatarsal is too long, it can be
shortened. However, this operation is not without risk. In addition
to the risks and complications common to all foot surgery,
reduction of load beneath the metatarsal can cause increased load
beneath the adjacent metatarsals (transfer pain). Stiffness of the
joint or a toe that sits up in the air (floating toe) can occur
with this type of surgery.
If the metatarsal is too prominent, then an operation to raise
it (dorsiflexion osteotomy) can be performed. This carries the same
risks as shortening osteotomy.
If capsule rupture alone is the cause of the problem, a repair
can be performed but this generally needs to be in the early stages
before any associated toe deformity becomes fixed.
The implications / recovery for this type of surgery are covered
under the related conditions.