MTP instability

Last evidence check March 2010

mti presentations

Symptom patterns in Peck et al (2006)

The typical patient is a middle-aged woman. Most patients have no history of trauma or inflammatory arthritis. There is a strong association with hallux valgus.

Peck et al identified three main patterns of symptoms:

Examination may show:

The Thompson draw test demonstrates instability with the MTP joint flexed slightly and the proximal phalanx drawn up and down.

It may be difficult to distinguish the pain of MTP instability from that of an interdigital neuroma. Indeed, Coughlin's series of neuromas had about 5% of patients who also had instability, and about the same proportion of Peck's MTP instability patients also had neuromas. Diagnostic injections are the simplest method of differentiating the two pathologies (Miller 2001). Ultrasound and MR will show both.


Differential local anaesthetic injections can help differentiate MTP instability from a neuroma

sites of tenderness

Distinguish between tenderness under the metatarsal head and under the MTP joint and plantar plate

The Thompson-Hamilton draw test. The MTP joint is in neutral. Dorsal and plantar leverage on the proximal phalanx subluxes and reduces the joint.