MTP instability

Last evidence check May 2010

A number of abnormalities may need to be addressed:

Synovitis without instability

Synovitis and irritabilitity with a partial thickness tear but little or no instability can be debrided arthroscopically - our early results in a few patients are good. However, even partial thickness tears can be associated with instability, presumably because of attrition and stretching of the remaining plate tissue. There is no data currently to tell whether these should be plicated or simply debrided.

Unstable MTP joint, can be reduced

mtp synovitis1

Synovitis with reducible instability and a hammertoe

mtp synovitis2

PIP arthroplasty to correct hammertoe. MTP soft tissue release is often required to correct the MTP joint hyperextension

mtp synovitis3

Flexor-extensor transfer to stabilise the MTP joint. Toe stabilised with a wire, usually into the metatarsal to protect the transfer

mtp synovitis4

Alternatively, stability can be obtained with a plantar plate repair and the wire left short

Thompson and Deland (1993) reported 8 painfree toes and 5 with mild pain out of 13 toes. Four had residual instability and six did not touch the ground. Stiffness of the MTP joint (less than 20deg total movement) was the main predictor of a poor result and they recommended transarticular wiring for 2 weeks only.

Gazdag and Cracciolo (1998) had 13 painfree toes, 7 with mild pain and 2 with disabling pain - there were no predictors of a poor result. Myerson (2005) reported 1/3 of 59 patients dissatisfied because of a stiff, often painful toe after this procedure.

Plantar plate repair

plantar plate repair1

Plantar plate tears are usually near the attachment to the proximal phalanx. They vary a good deal in size. Even a partial thickness tear may be accompanied by instability

plantar plate repair2

A curved plantar incision gives good access but avoids a scar under the metatarsal head. The neurovascular bundle is retracted. The flexor sheath is incised and the tendons retracted.

plantar plate repair3

The MTP joint is plantarflexed to reduce the plantar plate tear. Small tears in good quality tissue can be sutured. Large tears with little distal tissue can be treated by reattachment of the proximal plate to two suture anchors in the base of the phalanx.

Powless and Elze (2001) reported that eight patients (5 isolated plantar plate repairs, 3 plantar plate and collateral ligament repairs) were relieved of their instability and pain at review, but no more detail was reported on outcome. Gregg et al (2007) reported 35 procedures in 21 patients, all of whom had a Weil osteotomy as well as plantar plate repair from a dorsal approach. At an average of 26 months one toe had grade 2 instability, 9 grade 1 and 25 no instability. Five patients still had some pain. The average post-op AOFAS lesser ray score was 89 (no pre-op data available). There were 4 infections and one transfer lesion. Seventeen patients were satisfied with the result but the causes of dissatisfaction were not analysed. Bouche et al (2008) reported 15 patients who had PIPJ arthtoplasty or arthrodesis and stabilisation with both plantar plate repair and flexor-extensor transfer. The mean AOFAS lesser toe score was 83. Four patients were only partially satisfied, with residual forefoot pain; they also had first ray hypermobility. Five patients' toes did not touch the floor. Overall these results are similar to those of flexor-extensor transfer and an RCT against flexor-extensor transfer would seem to be appropriate.

Irreducible dislocation

dislocated mtpj

Synovitis with irreducible dislocation and hammertoe, often severe

dislocated mtpj3

After a Weil osteotomy the toe often lies in dorsiflexion ("floating toe"). A flexor-extensor transfer or plantar plate repair could overcome this.

mtpj dislocation2

If the MTP joint is good: PIP arthroplasty to correct the hammertoe MTP soft tissue release and often a Weil osteotomy to reduce the MTP joint


This will give a short floppy toe but almost always relieves pain and pressure.


If the MTP joint is severely eroded or scarred, a Stainsby procedure may be preferable

Where a Weil procedure has been used to reduce a joint, the total rate of recurrent deformity summed across the published series is about 15%. About 40% of MTP joints are stiff after a Weil osteotomy, and floating toes have been reported in 20-60%, although these are often asymptomatic. Boyer et al (2004) avoided floating toes with a flexor-extensor transfer and MTP transfixion with a wire. All MTP joints were stiff in their series but patients were not dissatisfied - however, Myerson's larger series must also be considered.


In elderly patients with severe or recurrent deformities of the second toe or fixed dislocation, an amputation through the MTP joint gives good pain relief with acceptable cosmesis (Anwar and Sundar 2002, Gallentine and De Orio 2005). Removal of the toe allows the great toe to fall into valgus, but these two series did not find this a clinically significant problem.

If disarticulating a fixed, dislocated second MTP joint, the plantar plate will usually be found adherent to the top of the MT head. This should be released and reduced, or the plunger effect will continue even in the absence of the toe.


Most patients are significantly improved by surgical reconstruction, but it is important to warn of: