Queensland Orthotic Lab, Author at Queensland Orthotic Lab Queensland Orthotic Lab, Author at Queensland Orthotic Lab

APOLLO Ulcer Rx Prescription Form (PDF)

QOL on the forefront of ulcer treatment

Led by Queanbeyan podiatrist Allan Donnelly, Queensland Orthotic Lab has released the APOLLO system for ulcer treatment. Allan is passionate about the health of diabetics and significantly lowering the number of lower limb amputations. He is also the Vice Chair of Wounds Australia ACT Branch. Allan has realized a gap in the treatment of diabetic foot ulcers – whilst total contact casting (TCC) is the gold standard in offloading diabetic foot ulcers, this doesn’t always translate into clinical practice.

Allan presented a prototype device (nicknamed APOLLO) at the Wounds Australia National Conference in 2018, where this device won the inaugural Innovation Tank Award. It won the award because of its accessibility, ease of use, low cost and longevity around effective plantar off-loading measures.

Developed in conjunction with QOL, the APOLLO device consists of a specifically designed total contact orthotic and a removable Aircast walking boot.

All that is needed is:

  • Plaster of Paris (POP);
  • Opsite or similar to cover the ulcer in the casting process;
  • Lipstick and;
  • Australia Post or appropriate courier.

Perhaps most importantly, the patient does not have to travel to a specialist clinic which means that any practitioner anywhere in Australia can cast for the APOLLO — with no technology required. This allows patients to receive a custom made total contact interface that, when combined with a good removable Aircast boot, replicates the best qualities of the TCC.

QOL can also design and supply a shoe-ready total contact orthotic to transition out of the boot at the appropriate time without needing to recast the patient. Furthermore, If the ulcer does relapse, the patient can get their APOLLO system out from the cupboard and wear it, even before seeing their health practitioner again to start the healing process.

Allan will be presenting the results of his study as an invited speaker at the 2021 Wounds Australia conference. QOL is now proud to offer the APOLLO device to podiatrists to help you get better outcomes for your patients. For more information on how the APOLLO system can help your patients, please contact QOL to be sent the APOLLO prescription form.

 

3D Printed – which thickness is best for my patient?

One of the common questions we get from clients who are prescribing 3D printed orthotics for the first time is “what thickness should I use?” Most podiatrists are familiar and comfortable with the material properties of polypropylene, subortholen, carbon fibre and EVA. But prescribing a new material can be daunting!

QOL prints in a material called Polyamide 11 (PA 11) or Nylon 11 (then branded internally as EnviroPoly). PA 11 is a polyamide, bioplastic and a member of the nylon family of polymers produced by the polymerization of 11-aminoundecanoic acid. It is produced from castor beans by Arkema, a global specialty chemicals and advanced materials company. PA 11 was around well before 3D printing – the first patents were filed in 1947.

Fundamentally, PA 11 behaves in a similar fashion to polypropylene. We’ve created this handy guide to help you navigate which thickness is best with an orthotic without any extrinsic posting:

 PA 11 Equivalents of Vacuum Pressed Materials

So if you would have previously prescribed a 3mm polypropylene device, the equivalent in PA 11 would be about 2.7-2.8mm. Or if you would have previously prescribed the polyflex device (2mm polypropylene with a 3mm EVA ILA filler), the equivalent thickness in PA 11 would be about 2.3-2.4mm.

One of the main advantages in prescribing PA 11 devices though, lie more in the fact that we’re utilizing additive manufacturing production – meaning we’re literally starting with nothing and adding layer by layer of powder to build the orthotic from the ground up. This means we’re not constrained to having the same thickness of material throughout the orthotic.

The design options for 3D printed orthotics are near endless. If you want to have a shell which is 2.7mm thick on the medial side and 4.2mm thick on the lateral side to control lateral instability – that’s no problems. Or if you want to taper the distal medial edge from 3.2mm to 1.5mm to improve first ray function – that’s no problem. The ability to vary thickness throughout the device is near limitless.

MLA ribs

Similarly, the ability to add stiffening components to the plantar surface of the device are an exciting breakthrough in prescribing custom orthotics. We’ve trailed a range of different stiffening techniques which allows the treating podiatrist to keep the shell thin and reduce the bulk for shoe fit, but reinforce and stiffen the device in the critical areas for the patient.

If you would like to discuss integrating 3D printing into your practice, contact Kent by email at kent@qol4feet.com.au, or make a booking here.3d options

Casting Tips to Improve Your Orthotic Outcomes

As one of the few remaining orthotic labs in the country to still provide a hand-crafted orthotic (using plaster modifications), we’re keen to continue this service. When manufacturing an orthotic this way, the emphasis of taking a good cast can’t be underestimated. A good cast is critical in producing a functional orthotic which is comfortable for the patient to wear. No amount of ‘lab discretion’ can replace capturing the patient’s anatomy in a repeatable manner. So what are the key elements in taking a good cast?

Patient Position
For supine casting, ensure the patient’s foot and distal 1/3 of the leg is hanging off the edge of the plinth. The lower leg should be horizontal or slightly declined.

If the leg is externally rotated, have the patient internally rotated at the hip or wedge up the lateral leg and thigh with pillows of towels. The long axis of the foot should be vertical.

Instruct the patient that you’ll need them to relax. For some patients this cue causes them to tense immediately! Ask them to let their whole leg go floppy. Look at the tibialis anterior tendon for signs of contraction.

Podiatrist Position
It’s critical that the podiatrist gets in the correct position. Ensure the patient’s foot is close to your chest. Keep the wrist in neutral so the bigger muscles of the shoulder are doing more of the work. This is one of the most challenging aspect of the casting techniques to master. Inexperienced practitioners may find this physically challenging. If this is the case, there’s a good chance you’re not in the correct position.

Load the MTJ
Insufficient loading of the midtarsal joint is one of the most common casting errors we see. In our experience there are more and more serious casting errors made in the positing of the midtarsal joint than in the positioning of the subtalar joint. In most feet, a few degrees of difference in the position of the STJ typically doesn't result in a dramatic change in the plantar shape of the foot. However, we see the MTJ as being more difficult to put in the proper casting position based on what we have seen in casts at the lab and in teaching students and practitioners the neutral position casting technique.

Insufficient forefoot abduction, dorsiflexion and eversion force can result in MTJ supination (i.e. creating a false forefoot varus), while excessive force can result in STJ pronation.

Work the Plaster
Use double layers of plaster and ensure good overlap between the rearfoot and forefoot splints. Spend some time initially working the plaster in to create a smooth, robust cast free of any air bubbles. Pay particular attention to areas of high curvature (e.g. medial longitudinal arch) so the plaster doesn’t gap from the foot.

Demonstrating air pocket in the medial longitudinal arch

Take Your Time
Don’t be in a rush to remove the cast. Removing it prematurely can undo all your hard work by causing the cast to buckle if it hasn’t set correctly. Setting times vary from batch to batch along with other external factors (e.g. temperature).

And Finally…
Don’t package your casts up straight away. They will continue to ‘sweat’ if put inside a box immediately, which again will undo all of your hard work. Ideally let them casts dry in ambient air for 24 hours prior to dispatch. Otherwise you can microwave for a few minutes the casts or use a heat gun on them to help them fully cure.

By following these steps, you’ll be sure to produce a good cast which accurately represents the patient’s anatomy. This will give your lab the best chance of manufacturing an orthotic to help give you great patient outcomes.

completed cast

Eliminating Paper Prescriptions

Do you want to eliminate paper forms and time spent scanning prescription forms in your practice? QOL have developed an online portal to allow you to upload prescriptions and digital scans in a secure
manner – MyQOL.

Even if you use physical casts (i.e. plaster, STS sock or foam box), you can still take full advantage of MyQOL. This allows you to go to a paperless ordering system and keep all of your prescriptions in one place. You can quickly search by first name, last name or job number to review old prescriptions. And if you wish to have that saved into your practice management system, it’s easy to save the completed prescription as a PDF and import into your patient file.

Unlike some competitors, we understand that feet are often asymmetrical. So when we receive the casts or scans, the first thing we do is to evaluate the feet and note if one foot it lower/longer/wider compared to the other foot. We communicate this through to our technicians but this also needs to be communicated back to you, the treating podiatrist. Just like our current paper prescription forms, we’ll make a note in MyQOL of things like the forefoot to rearfoot evaluation and any asymmetrical morphologies (e.g. one heel is wider than the other or one foot is longer the other). This allows you to see what we’ve seen in our measurements while also cross-referencing that to the actual orthotics.

The prescription form is set out almost identically to our paper prescription form and allows you to take advantage of our full range of traditional materials such as polypropylene, subortholen and carbon fibre and newer materials such as the 3D printed PA-11 and milled EVA. See MyQOL in action in this short video. If you wish to utilize our online portal, please register your interest in a trial here or contact the lab and we can set you up with an account.

Clinical Pearls for the Flat Foot Patient – Part 2

In part 1 of this 2 part blog, we explored the pathophysiology and clinical assessment of patients with a painful flatfoot. Understanding the stage at which your patient presents gives clear direction as to the best course of conservative treatment. This blog will focus on orthomechanical treatments. In all stages, physical therapy which includes balance exercises are critical and when appropriately coupled with orthomechanical care will lead to a much better chance of good outcomes. Of course surgery may be required in some cases, but with strict adherence to conservative treatments, surgery can be minimized.

 

Stage 1

In stage 1, we’re primarily dealing with a posterior tibial tendinopathy in a flat foot. In some cases, patients may require short-term immobilization to effectively settle their pain. Most patients in this stage benefit from a well-made custom foot orthotic. The pronatory forces are large in these patients (irrespective of the size of the patient themselves), so a large amount of force on the medial side of the subtalar joint axis is needed. As such, prescription parameters may include:

  • Semi-rigid to rigid shell material – 3.5mm to 5mm shell thickness.
  • Deeper heel cups – usually over 16mm.
  • Medial heel skive – 4mm and above.
  • Medial flare/flange – assists with transverse plane control through the talonavicular joint.
  • Extrinsic rearfoot post – increases rearfoot stiffness of the orthotic.

 

Stages 2-4

Usually by the time a patient is classified in stage 2, the key ligamentous structures (e.g. spring ligament) are involved which leads to discernable change in foot morphology – the symptomatic foot is flatter compared to the asymptomatic foot. Patients find it difficult to perform a single leg heel raise.

Where ligamentous involvement is clear, the preferred orthomechanical treatment is a custom ankle-foot-orthosis (AFO), rather than just a foot orthosis. The AFO helps to restore the coupling between the leg and foot which reduces with ligamentous attenuation or rupture.

The Richie brace is a custom AFO which podiatrists can prescribe from a cast of the lower leg and foot. For stages 2 and 3, the following prescription parameters can be followed:

  • Standard Richie brace – this allows for normal sagittal plane motion at the ankle (i.e. normal plantarflexion and dorsiflexion), but helps to restrict the pathological frontal and transverse plane forces acting through the rearfoot.
  • Medial heel skive – 4mm and above.
  • Lateral flare/flange – many of the patients have forefoot abduction and can slide laterally off the foot plate. A lateral flare/flange will control that forefoot abduction.
  • Full rearfoot post – the Richie brace range comes with a small heel stabilizer bar as the extrinsic post. Changing to a full rearfoot post increases the rearfoot stiffness of the AFO.
  • Medial malleolus accommodation – a lot of force is transmitted onto the medial upright in the area of the medial malleolus. This is required to resist internal tibial rotation. For some patients, this can be a source of irritation. By requesting a medial malleolus accommodation, extra plaster will be added to the area so the medial upright bows out in this area.

 

For stages 3-4 a standard Richie brace may not be sufficient to control the deformity, in which case the following prescription parameters may be better suited:

  • Medial arch suspender Richie brace – it is important to note that the medial arch suspender brace is built on a restricted hinge brace. This means the uprights are fixed at 90° to the foot plate which virtually restricts all sagittal plane movement at the ankle. A medial arch suspender strap can not be added to a standard Richie brace. To manufacture the medial arch suspender Richie brace, the plastic shell is cut out in a semi-circular shape under the medial longitudinal arch, a thin layer of cork is laminated in the area of the cut-out and a strap is attached underneath which wraps around the medial midfoot, across the anterior ankle up to a D ring on the lateral upright. The patient can then self-tension this strap.
  • Medial heel skive – 4mm and above.
  • Full rearfoot post – the Richie brace range comes with a small heel stabilizer bar as the extrinsic post. Changing to a full rearfoot post increases the rearfoot stiffness of the AFO.
  • Medial malleolus accommodation – a lot of force is transmitted onto the medial upright in the area of the medial malleolus. This is required to resist internal tibial rotation. For some patients, this can be a source of irritation. By requesting a medial malleolus accommodation, extra plaster will be added to the area so the medial upright bows out in this area.

Note the medial arch suspender Richie brace is contraindicated in very obese patients as the shell cut-out weakens the brace. It is also contraindicated for patients with severe forefoot abduction.

 

flatfoot collage

What If I’m Unsure?

We commonly talk with podiatrists who are unsure if they should prescribe the standard Richie brace or the medial arch suspender Richie brace. Generally speaking if the patient has a fairly rigid rearfoot with plantar subluxation of the medial cuneiform, the medial arch suspender Richie brace is appropriate.  If the rearfoot has normal or only slightly reduced range of motion and there is no plantar subluxation of the medial cuneiform, the standard Richie brace is more appropriate.

Finally, a standard Richie brace can be converted to a medial arch suspender Richie brace if needed. However a medial arch suspender Richie brace can not be converted back to a standard Richie brace.

 

 

3 steps to convert from plaster to scanning

Clinical Pearls for the Flat Foot – Part 1

When adults present to your clinic with ‘flat feet’, it can present an interesting enigma – why do some flat feet function normally and pain-free, yet other are painful and cause disability? We now know the answer to that question is the soft tissue changes that occur in some patients and not in other.

The dynamic supporting structures of the foot include:

  • Plantar aponeurosis
  • Posterior tibial tendon
  • Plantar intrinsic musculature – Dr Luke Kelly and colleagues have done some wonderful work in this area.

Whilst many are taught that the posterior tibial muscle and tendon are responsible for ‘holding up the arch’, we know through cadaveric studies that the plantar aponeurosis has a 3-fold greater power of arch support compared to the posterior tibial tendon.

The static supportive structures of the foot include:

  • Spring ligament complex
  • Superficial deltoid ligament
  • Interosseous talocalaneal ligament
  • Long and short plantar ligaments
  • Plantar aponeurosis – note both a static and dynamic supporting structure.

Two of the most prominent researchers in this area, Dr Jonathan Deland and Dr Mark Myerson, have repeatedly demonstrated that the sequential failure of these key ligaments is what causes a pathological flat foot, rather than an isolated failure of the posterior tibial tendon. This is why we prefer the term ‘adult acquired flatfoot’ rather than ‘posterior tibial tendon dysfunction’ to describe the much broader pathology.

That being said, it is important to note that patients will have a pre-existing flat foot and pathology will start in the posterior tibial tendon. The tendon will become inflamed and painful which is the first stage in any classification scheme. Accurately diagnosing patients with posterior tibial tendinopathy or tenosynovitis and managing them appropriately can have a drastic effect and stop them from progressing into a much more disabling pathology.

A thorough history taking is vital in these patients. They will usually give some good clues in their history. These may include:

  • A history of always having flat feet
  • More recently one foot has become painful
  • They are aware of swelling around the posterior aspect of the medial malleolus
  • In some patients they’ll be aware that one foot has become even flatter
  • Some patients may report some improvement in pain when wearing hiking boots

The key with the clinical examination is to conduct assessments which enables you to classify the patient. We recommend the following classification scheme based on the 2007 Myerson classification scheme and the 1989 Johnson & Strom classification:

Flat Foot Classification Scheme

The clinical examination should include the following:

  • Gait assessment – look for a limp which indicates pain and impairment. You may also detect the foot stays pronated in late midstance, when in fact it should be resupinating.
  • Single leg heel raise – arguably the most critical examination in these patients as this gives a good indication if there is ligamentous failure or not.
  • Jack’s test – look for resupination of the arch and external rotation of the leg.
  • Single leg Rhomberg – a simple balance test can be revealing for both the podiatrist and the patient.
  • Joint ROM (hip to toe) – is the deformity rigid or flexible?
  • Manual muscle testing – by isolating the posterior tibial muscle, both you and the patient can feel the weakness.
  • Supination lag – another muscle test where the patient is able to see the affected foot isn’t able to come towards the midline effectively.
  • Palpation for pain – is the pain isolated to the medial ankle or is the lateral aspect of the subtalar and ankle joints involved?

A thorough history and physical examination, coupled with a good understanding of the pathophysiology is vital in understanding the best treatment options for patients. If both you and the patient has an understanding of the extent of the pathology (i.e. isolated to the posterior tibial tendon or more widespread ligamentous involvement), effective treatment can be initiated.

 

 

How Should I Prescribe for Plantar Heel Pain?

Plantar heel pain is the most common presentation of musculoskeletal pain to most podiatrists in private practice.  There is still much debate on the cause of pain and the term ‘plantar heel pain’ probably encompasses several diagnoses.  For the sake of this blog post, we’ll focus primarily on what is commonly referred to as ‘plantar fasciitis’ or ‘plantar fasciopathy’.  This presents with the classic post-rest pain (or post-static dyskinesia). Note – if the patient doesn’t have post-rest pain, I’d be considering other differentials.  We know this condition affects more females than males, is more likely to occur in adults over 40 and is more likely in overweight or obese people.

If you’ve recommended custom foot orthotics be part of your treatment plan, are there prescription parameters you should consider?  Whilst I’m strongly against a cookie-cutter or recipe type approach to treating any pathology, there are certainly some prescription parameters to consider for plantar fasciitis.

Before we get to those prescription parameters though, I think it’s important to take a step back and think about what the likely contributing factors are.  In plantar fasciitis, I think there are a couple of key things which contribute to the development of this condition:

  1. Increased strain on the central band of the plantar fascia, and
  2. Increased ground reaction force on the heel.

We know that increased STJ pronation alone doesn’t lead to plantar fasciitis.  If that was the case, then only people with a pronated foot type would develop this problem.  We know that this problem can occur in any foot type – supinated, neutral or pronated (basic classifications, but you get the point!).

So if we need to look beyond the STJ as a mechanical explanation, what else could be contributing?  Potentially what can occur is: either a forefoot valgus or STJ pronation leads to 1st ray dorsiflexion and inversion – this causes the midtarsal joint to supinate, eccentric contraction of flexor hallucis brevis and abductor hallucis and a lowering of the MLA – these can all increase the strain on the plantar fascia.

In terms of treatment then, I think one of the best papers to give us a clue here, was Kogler’s 1999 cadaveric study.  Kogler and colleagues took 9 cadaveric specimens and inserted load transducers into the plantar fascia. Each specimen had an axial load through the tibia of up to 900 Newtons exerted through it.  6-degree wedges were applied in different combinations under medial and lateral rearfoot and forefoot and the load was measured through the plantar fascia. It was found that wedge under the lateral forefoot (forefoot valgus wedge) significantly decreased load through the plantar fascia, whilst a wedge under the medial forefoot (forefoot varus wedge) significantly increased strain through the plantar fascia.  Rearfoot wedging alone did not produce a significant change in plantar fascia strain.

When it comes to orthotic prescription then, what are some of the things you should consider?

How to take the impression:

  • STJ in neutral with the MTJ fully pronated (reduce forefoot supinatus by plantarflexing the first ray).  Capturing a forefoot valgus in the cast/scan provides a better outcome, rather than trying to ‘manufacture’ it in the design process!

Positive cast or CAD modifications:

  • Pour vertical
  • Plantar fascia accommodation (3-4mm), blended so as not to cause irritation on the medial or lateral margins of the accommodation
  • Potentially a minimal arch fill design if the foot mechanics warrants it
  • Accommodations for any fibromas or tears
  • Avoid medial heel skives (this can increase ground reaction force at the medial calcaneal tubercle)
  • Intrinsically post a forefoot valgus if captured in the cast/scan – this is critical!

Shell considerations:

  • Semi-rigid material, appropriate for foot mechanics, patient size and activities
  • Heel apertures and pads
  • Deep heel cups (>16mm)
  • Intrinsic forefoot valgus
  • Potentially extrinsic forefoot valgus wedging

Whilst we recommend you consider these prescription variables when prescribing orthotics for plantar fasciitis, it’s important to remember not to take a cookie cutter type approach to dealing with any pathology and to treat the individual in front of you.

Kogler GF, et al. The influence of medial and lateral placement of orthotic wedges on loading of the plantar aponeurosis. J Bone Joint Surg Am. 1999 Oct; 81(10):1403-13.