Participant characteristics

The characteristics of the 12 podiatrists included in the study are presented in Table 1. The number of years in podiatric practice ranged from eight to 44. Most participants received their initial education in Aotearoa New Zealand and two thirds went on to obtain postgraduate qualifications. All participants practiced in the private health sector.

Table 1 Participant characteristicsAssessment of sesamoiditis

Four major themes were constructed relating to assessment and diagnosis of sesamoiditis: (1) obtaining a patient history; (2) recreating patient symptoms; (3) determining contributing biomechanical factors; and (4) ruling out differential diagnoses (Fig. 1).

Fig. 1

Themes representing podiatrists’ approach to the assessment of sesamoiditis

Theme 1. Obtaining a patient history

Obtaining information about patient-reported symptoms was described as important by most practitioners:

“I probably try to get a lot of information from my subjective assessment which is then gonna guide to the approximate region that the person is talking about, try to work out what kind of tissues are involved” (P03).

In addition to determining whether the symptoms represented acute or chronic pathology, practitioners also focused on understanding the mechanism of injury:

“I get them to, if they can, replay or show me the mechanism” (P05).

Mechanisms subjecting the 1MTPJ and sesamoids to high loads and stress were considered useful in establishing a diagnosis. Many podiatrist also noted a link between sesamoid injuries and sports involving firm surfaces, high propulsion, rotational movements, and/or repetitive movement and impact:

“Early season rugby [or] football training where the ground is still hard, there seems to be a little bit of an influx where you might get quite a few people in with pain in that sesamoid area” (P02).

Theme 2. Recreating patient symptoms

Direct palpation of the sesamoids was the most common method used to elicit symptoms:

“I normally just push on the sesamoid bone and go, oh, yeah” (P06).

Some podiatrists also described performing a passive axial compression test which allowed them to.

“ … get in there and give it a good wobble” (P08).

This test involved placing the hallux in a maximal dorsiflexed position (causing distal migration of the sesamoids), before applying proximal compression to the sesamoids to stabilise them. The hallux is then plantarflexed and if symptoms are produced this indicates a positive test.

Dynamic tests such as resisted muscle testing, hopping tests, and heel raises were also commonly used to recreate symptoms by testing the sesamoid pully function and simulating the propulsive phase of gait:

“I like the calf raises, seeing how much they can tolerate, whether they can only do double leg or whether they can do single leg.” (P06).

Theme 3. Determining contributing biomechanical factors

After establishing the diagnosis of sesamoiditis, additional assessments aimed at determining contributing biomechanical factors made up a large part of the initial appointment. Some assessments were specific to the sesamoid area and included testing of 1MTPJ range of motion and first ray position (relative to the other metatarsal heads) to gain a better understanding of the windlass mechanism and loading during propulsion. The degree of transverse sesamoid translation and potential subluxation as a cause of local inflammation was also considered:

“Sometimes, in my opinion, that lateral sesamoid tends to be slightly more deviated so I like to give it a bit of a push from lateral and medial to see if that exacerbates any pain” (P10).

Practitioners frequently reported seeking further information about the rearfoot to forefoot relationship by assessing rearfoot position and overall foot posture:

“If they have a particular foot type where the way that they walk is really overloading that particular area … working around that and thinking more of the long term and thinking more preventatively as well so it doesn’t become a recurring issue for them” (P02).

Some podiatrists also considered assessment of the entire lower limb, including leg length discrepancies and hip positions in order to determine whether more proximal factors could be contributing:

“I start at the pathology site of concern and then work my way in reverse trying to look for patterns that could explain why this is occurring” (P04).

In addition to these static non-weightbearing assessments, podiatrists also sought to improve understanding of the patients walking or running mechanics and how these may have contributed to development of sesamoiditis:

“ … depending on what activity they do, say, they’re doing sport or something, I probably go and get them having a bit of a run, just to see what aggravated it” (P07).

Practitioners who had plantar pressure systems in their practices also found these beneficial:

“Weight distribution point of view, with a in shoe pressure or pressure plate is actually a good assessment tool in terms of understanding loading patterns through that joint.” (P12).

Finally, biomechanical-based assessments also extended to the patients’ footwear to gain an understanding of their role in the development of sesamoiditis:

“I quite like looking at the insole of the shoe too, pulling that out and having a look and see if there’s any obvious wear pattern can sometimes be a give-away” (P04).

Assessment of sprig placement on rugby and football boots, particularly if positioned beneath the 1MTPJ, was also of interest. Shoes with poor structure and a minimalistic sole style were often reported as causative factors due to lack of cushioning and increased sesamoid loading, as was fit of the shoe:

“Sometimes people buy a boot that’s too small or too big and that really affects [how] that metatarsophalangeal joint extends and flexes” (P05).

Theme 4. Ruling out differential diagnoses

Podiatric tests were undertaken by the podiatrists in order to rule out other sesamoid pathology, including fractures, bipartite sesamoids, and avascular necrosis. Pathology of neighbouring structures, including ligaments, joint capsules, plantar plates, distal insertions of the flexor hallux longus and brevis tendons and the insertion of the abductor hallucis and plantar fascia were also considered. These assessments were based on utilising detailed knowledge of local anatomy:

“I think we forget sometimes that we actually probably know the foot anatomy better than anyone else” (P08).

Direct referral for imaging investigations, including ultrasound and plain radiography were sometimes used to further assist in ruling out differential diagnoses:

“I don’t tend to use much; I think mostly it’s a clinical thing. If I’m suspecting a fracture or bipartite sesamoid or something like that, potentially an x-ray” (P03).

In some situations, CT and MRI were also considered valuable, however, referral to these services within the Aotearoa New Zealand funded health system pathways were challenging for podiatrists and their patients. Under the Accident Compensation Corporation (ACC) scheme podiatrists can refer for plain radiography and ultrasound, but any further funded imaging requires a referral through a sports physician or orthopaedic surgeon, which places another step and time delay in the referral pathway:

“I would like to be able to at some stage, refer for MRI or CT, because I think we know enough to do it but … it’d be great to see in greater detail what’s happening in a specific joint” (P05).

Practitioners in the current study also reported referring to other health professionals to conduct assessments that were beyond their scope of practice, including to general practitioners for blood tests to rule out underlying systemic causes of sesamoid inflammation and to sports physicians or orthopaedic specialists when imaging outside of plain radiography and ultrasound were required.

Management of sesamoiditis

Seven major themes were constructed relating to the management of sesamoiditis. These were: (1) consideration of patient factors; (2) patient education; (3) cushioning of the sesamoids to allow more comfortable weightbearing of the 1MTPJ; (4) pressure redistribution and offloading of the sesamoids; (5) immobilisation of the 1MTPJ and sesamoids; (6) facilitating efficient sagittal plane motion during gait; and (7) referring to other health professionals to find different ways to treat or manage patient symptoms (Fig. 2).

Fig. 2

Themes representing podiatrists’ approach to the management of sesamoiditis

Theme 1. Consideration of patient factors

The podiatrists in the focus groups agreed that there was no single effective approach to treating sesamoiditis:

“Something obviously will work for someone and it doesn’t work for someone else so, … creativity is key here … is it gonna fit into the shoe? Is it really realistic workwise? How long are they gonna be weight bearing on it from day-to-day? Is it durable? All of these variables you have to take into consideration when you are creating a management plan” (P10).

Several podiatrists also spoke about the patients’ financial situation, particularly when prescribing orthotics or recommending footwear, both of which can be expensive investments.

“I’ll start really simple, like … just modifying the insole/sock liner if it’s on the lower budget end. If we’ve got a little bit more money to work with then we’ll do a prefab or a custom orthotic” (P06).

The cost-barrier was particularly evident for podiatrists working in lower socioeconomic rural areas where many podiatrists also struggled with access to suitable and appropriate footwear options.

Theme 2. Patient education

Improving patient understanding through clear education and communication was considered essential to an effective management programme:

“I’m gonna spend that time educating them about what I think it is and how I think we’re gonna manage it and also what I think my goal posts are gonna be” (P09).

Reduction of pain and inflammation was a central focus of patient education. For many podiatrists, education also encompassed training and load management principles involving activity modification until symptoms reduced. RICE (rest, ice, compression, elevation) was recommended for acute stages of sesamoiditis, but most podiatrists discussed pharmacological management with their patients. As podiatrists in Aotearoa New Zealand are limited by an absence of prescription rights, this involved recommending over-the-counter medications, or referral to a pharmacist or GP to provide prescriptions:

“I’m not a pharmacist so I don’t wanna get in trouble, but I certainly do recommend a course, just to take the edge off” (P10).

Some practitioners highlighted the importance of communication and education when patients’ expectations may have been less realistic:

“I am really brutal about women’s footwear, and I basically refuse to treat anything which is gonna make my treatment compromised so I do sit down with people and have a pretty hard talk about how we’re gonna make it work” (P09).

Theme 3. Cushioning of the sesamoids to allow more comfortable weightbearing of the 1MTPJ

Cushioning of the sesamoids was considered during initial stages to allow more comfortable weightbearing through the 1MTPJ. This was achieved through footwear and/or orthoses.

Providing advice to patients about avoiding thinner soled shoes (i.e., racing flats) and option for trainer-type footwear with adequate cushioning was commonly reported:

“I’d say rocker sole, really thick cushion shoes and then gel forefoot cushion shoes” (P06).

Likewise, avoidance of high-heeled shoes, which not only lack cushioning, but also increase forefoot load was also important:

“I think it kind of goes without saying … it’s obviously avoiding high heel shoes. Probably a really important point to make in your management” (P08).

Further cushioning via orthotic prescription was achieved via the addition of softer materials:

“I’ll use a softer based orthotic. We usually use a cushion foot bionic and pretty much some kind of first MTP pad, often double layered and, again, well bevelled” (P09).

Theme 4. Pressure redistribution and offloading of the sesamoids

The use of a moonboot to offload the sesamoids was described in situations where the patient had difficulty weight-bearing, where a fracture was suspected, or where severe or acute inflammation of the sesamoids was evident:

“ … in a moon boot for a week … that generally works pretty well to help settle things down” (P02).

Padding, using either semi-compressed felt or poron, which was applied to the liner of the moon boot or shoe, or directly to the patients feet, was also used as a temporary offloading technique:

“Patient turns up and there’s no way you’re gonna get a prefab or something into a [dress] shoe, so just a simple offloading principle as soon as you can, if there’s no other option. Certainly it’s only a very temporary method because most of that padding will break down” (P11).

Orthoses were used for more permanent offloading of the sesamoid area including plantar ‘U’ covers, first ray cut-outs, and metatarsal domes. Reverse Morton’s were often combined with arch fill to redistribute pressure from the sesamoids to the arch area:

“2 to 5 s [reverse Morton’s] just seem to work. I know they shouldn’t but for some reason they seem to work quite well” (P05).

However, other podiatrists were concerned that this modification would load the area further:

“I’d never think to do a reverse Morton’s because I’d be too concerned with plantar flexing that first ray, that you would get more pain” (P08).

Materials were also discussed as an important consideration when constructing orthotic modifications for offloading the sesamoids:

“Definitely does depend on the foot that we’re seeing. The majority of the time, I’d do a firm density EVA that’s relatively thick.” (P10).

Finally, many podiatrists also discussed sprig removal in football boots as a mechanism to offload pressures at the plantar 1MTPJ:

“Another thing I often do … with football boots I typically take that cleat out under that first metatarsal phalangeal joint as well” (P08).

Theme 5. Immobilising the 1MTPJ and sesamoids

Podiatrists reported using strapping tape as a technique to immobilise and resist movement at the 1MTPJ during the propulsive phase of gait and to determine the potential effectiveness of orthotic therapy:

“I do a bit of strapping tape as well to reduce the motion of the first MTPJ and if that feels really good then I’ll implement that into an orthotic with a Morton’s extension” (P10).

A Morton’s extension was the preferred orthotic modification by many podiatrists to immobilise the 1MTPJ and prevent loading through the sesamoid pivot. However, as the Morton’s extension follows the opposite concept to a reverse Morton’s (i.e., immobilisation vs. offloading), this modification was sometimes used with caution and viewed as a temporary immobilisation strategy:

“If we restrict one joint and typically what you do with the Morton’s extension is we don’t open up a can of worms for other injuries or pathologies” (P08).

Other podiatrists described changing the density of the Morton’s extension (usually a hard plastic) to a softer material over time as the sesamoid inflammation reduced or covering the modification with a softer plantar top cover.

Stiff carbon fibre plates were used when a greater degree of immobilisation was required:

“I’ve got [rugby] players that are actually still playing in them all season even though [the ground has] got really soft and they’ve just been using it cos it gives them some stiffness through scrummaging and changing their load” (P05).

Carbon fibre material was sometimes combined with orthotic therapy. However, it was used with caution by some due to patient acceptability and comfort, particularly when combined with orthotic therapy:

“I don’t find there’s enough room for an orthoses either prefab or custom and a carbon plate unless you’ve got something like a work boot scenario” (P12).

Theme 6: Facilitating efficient sagittal plane motion during gait

Facilitating a more efficient heel-to-toe gait pattern was a key theory influencing many management techniques for sesamoiditis:

“I’m trying to enhance sagittal plane movement to try and move them through that area more quickly or change loading through the forefoot to redistribute load more evenly away from that area.” (P03).

Podiatrists often recommended shoes with rocker soles to facilitate propulsion through the 1MTPJ:

“That great little rocker through there makes a massive difference to unloading that joint because minimal extension takes place in the toe when they’re walking” (P11).

In addition to footwear, inclusion of strengthening exercises targeting the flexor hallucis longus muscle and other intrinsic foot muscle was believed to encourage more efficient loading through the 1MTPJ during propulsion. Other podiatrists described using towel grip exercises, resisted flexion and spikey ball exercises to increase strength in the intrinsic foot musculature.

Long term orthotic modifications were also focused on improving more efficient loading through the 1MTPJ. Customised plantar metatarsal pads (PMP), kinetic wedges, and metatarsal bars were forefoot orthotic modifications used by participants to help sagittal plane motion:

“ … using something like a PMP to try and spread load across that part of the foot so that I can allow them to carry continuously through or efficiently through the sagittal plane without excessively placing load on the first MPJ” (P03).

The podiatrists also recognised the importance of rearfoot posting to facilitate sagittal plane motion while also preventing excessive loading of the medial forefoot.

Theme 7. Referring to other health professionals to find different ways to treat or manage patient symptoms

Referral to wider interdisciplinary team members for further management was discussed among the participants as an approach for patients whose symptoms did not reduce with podiatry care.

Referral practices were dependent on specific time frames for many podiatrists:

“I feel like sesamoiditis, you get a fairly quick indication of whether your treatment plans’ working but maybe four to six weeks if it wasn’t working, I’d go and refer on” (P07).

Some practitioners referred earlier to factor in the waiting time to see a sports physician or orthopaedic surgeon.

It was clear among the participants that there was hesitancy in referring for more invasive therapies due to side effects and low success rates and were often only considered as last resorts:

“If we haven’t got the skills to do it ourselves, then there’s really only the surgeon and, as I say, I haven’t found surgery to be successful for sesamoiditis but maybe I haven’t seen enough” (P01).