Orthoses for Plantar Plate Injury by Nick Knight

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Top podiatrist Nick Knight joins us again today to follow up his extremely popluar guest blog on Plantar Plate Injury. He’ll be taking you through a quick step by step guide to creating orthoses for this painful condition.

Follow Nick on Twitter via @NKSportsPod and be sure to check out his previous articles. Well worth a read!

I’m really pleased my initial Plantar Plate blog has been so popular! I’ve been getting questions around the orthoses I use in clinic, so thought it would be a good idea to show a step by step guide. It is important however to point out that orthoses are just a part of the treatment process.

I have recently started using a rigid carbon insole with a forefoot rocker for 6 weeks, to help stiffen the forefoot and help to reduce the pain and our clinical data is showing it to be helpful.

Usually we ask patients to wear a stiff soled walking boot or rocker sole. Using the carbon insole which has a forefoot rocker means we can keep patients in their normal shoes. We put the carbon lining under orthoses or existing shoe linings


Carbon Insole

From the orthoses prescription, there is no peer reviewed published data regarding the prescription that I am aware of, it was a prescription I was first made aware of Dr Kevin Kirby1.

First part of the prescription is a metatarsal dome, that just sits proximal to the effected MTPJ. The aim of the metatarsal dome is to try and dorsiflex the metatarsal. The orthoses used here was on a preformed shell and modified (Interpod flex 4 degree). This prescription can be used on custom orthoses if you need to adjust the orthoses shell size, thickness and heel cup.

Metatarsal Dome

Then I add the sulci extension, with a ‘U’ cut out around the effected MTPJ, the important part is to make sure the ‘U’ cut sits just distal to the MTPJ. The aim is to allow the toe to plantarflex into the ‘U’ cut out or on more medical speak, to try and dorsiflex the metatarsal and plantarflex the proximal phalanx. If the metatarsal dome and ‘U’ cut out is too proximal it may result in the toe dorsiflexing into the ‘U’ cut out and increasing in symptoms.

Metatarsal dome and 3mm cork sulci extension 
Metatarsal dome and 3mm cork sulci extension (from beneath)

Finally, we add the cover of choice. The cover is often neglected and an afterthought. However it is an important factor. A leather cover will offer low friction, so may increase some slipping on the orthoses. EVA will offer increased friction and less slipping. Think about what you think is best for the patient.

Finished Orthoses

Hopefully this has answered some questions and offered some useful insight.

Nick Knight – https://nksportspodiatry.co.uk

References

  1. Kirby KA: Foot and Lower Extremity Biomechanics III: Precision Intricast Newsletters, 2002-2008. Precision Intricast, Inc., Payson, AZ, 2009, pp. 107-108