Anatomy
The foot has two arches. A longitudinal elastic arch (which when dropped results in flatfoot) and a transverse elastic arch at the front of the foot around the pads under the toes. Forefoot drop is also called forefoot flatfoot. The forefoot arch distributes the pressure of foot strike across all toes. A high instep predisposes to forefoot drop.
Cause of the problem
Normally, pressure is relieved by walking on the 1st and 5th toes, which is why there is often calluses under these toes. With repeated loading (e.g. running and pushing off), the front arch of the foot weakens and sinks down, causing the joint heads of the 2nd and 3rd toes to become increasingly stressed, resulting in the joint heads sliding upwards and a characteristic toe position called ‘hammer toes’.
The stress on the joint heads of the 2nd and 3rd toes causes strain pain, and in hammertoes, the middle joint of the toes can collide with the shoe ceiling, which can also cause pain. In forefoot drop, the nerves between two toes can be pinched (Morton’s neuroma) (Munir U, Tafti D, Morgan S. 2023).
Symptoms
Pain under the centre of the forefoot when pressing and pushing off. There will almost always be calluses under the joint heads of the 2nd and 3rd toes (MTP joints). Morton’s neuroma also causes pain and sensory disturbances, usually on the inside of the 4th toe and the outside of the 3rd toe. The pain can progress to be debilitating in sports.
Examination
Diagnosis is made by clinical examination. There is pain on pressure under the base of the 2nd and 3rd toes where there is callus. Imaging is rarely necessary. An ultrasound scan can show irritation in the metatarsal joints (synovitis).
Treatment
Relief from pain-inducing activity. Forefoot inserts in the shoe (‘forefoot pad’) restore the arch and relieve the joint heads of the 2nd and 3rd toes in the metatarsophalangeal joints (MTP-2 and -3) and distribute more pressure to the 1st and 5th toes. Shoes should have a rigid sole to limit backward flexion (extension) of the toes. High-heeled shoes and (sports) shoes with an elevated heel (heel cup) should be avoided.
If an ultrasound scan shows fluid (synovitis), an injection of adrenal cortex hormone into the toe joint can be tried. For severe pain and hammertoes, surgery may be necessary, but as the metatarsal joint is removed and stiffened, it will often not be possible to return to foot-loading sports at the same level.
Complications
However, if the progress is not smooth, you should consider whether the diagnosis is correct or if there are complications:
In particular, the following should be considered:
- Arthritis disease of the toe joints
- Mortons neuroma
- Bone fracture
- Stress fracture in the femoral neck
- Plantar plate lesion under the toes
- Joint cartilage damage, osteoarthritis
