Diagnostic Assessment — Left Foot - Sesamoiditis
Example 1 of 1 · fictitious patient (Veteran BN)
Diagnostic Assessment
Left Foot - Sesamoiditis
No Statement of Principles applies to this condition (non-SOP claim).
ADF History
Veteran BN, date of birth 27 April 1985, Australian Army, Infantry Soldier (Paratrooper), later Corporal, enlisted 05 July 2004, medically discharged 18 October 2018. Operational service: Afghanistan, 01 March 2012 to 30 October 2012 (warlike); Middle East Area of Operations (Iraq), 12 April 2015 to 20 November 2015 (warlike).
Occupational History
As a paratrooper and infantry section commander the veteran made regular static-line parachute descents with heavy equipment loads, and conducted pack marches, foot patrols, running, drill and obstacle courses in issued combat boots, frequently on hard, rocky and uneven ground. Patrols often involved climbing, scrambling on steep slopes and jumping from walls and vehicles.
These duties concentrate repeated high loads on the forefoot and the first metatarsophalangeal joint, and carry a high risk of forefoot impact injuries, sesamoid stress reactions and fractures, plantar plate injuries and other overuse injuries of the foot. On operations, access to podiatry, orthotics, imaging and specialist care was limited.
History
Veteran BN, a paratrooper and infantry section commander in the Australian Army, developed sesamoiditis of the left great toe on 18 July 2012 while on warlike service in Afghanistan, after a forefoot landing injury, a sharp increase in patrol load and months of running and load carriage in rigid boots on a high-arched foot with a stiff big toe. The condition worsened in Iraq in September 2015, with MRI showing progression to a stress fracture of the medial sesamoid.
Timeline
- 14 Mar 2011 — At a podiatry review for forefoot callus the veteran was recorded as having a left pes cavus foot with a plantarflexed first ray, early hallux limitus with 40 degrees of first metatarsophalangeal dorsiflexion, a mild hallux valgus of 18 degrees and tight calf muscles. Custom orthoses were recommended but not supplied before deployment. "pes cavus, plantarflexed first ray"
- 10 Apr 2012 — While on warlike service in Afghanistan he presented with an acute flare of reactive arthritis following an episode of Campylobacter gastroenteritis, affecting both knees and the left first metatarsophalangeal joint. He was HLA-B27 positive and was treated with naproxen. A rheumatologist later classified the condition as a peripheral spondyloarthropathy. "reactive arthritis, L 1st MTPJ"
- 02 Jun 2012 — He landed heavily on the ball of his left foot when jumping about 2 m from a compound wall under a 40 kg load. He had immediate pain under the big toe joint and limped for several days. The medic recorded bruising beneath the first metatarsal head. "heavy landing L forefoot, bruising"
- 21 Jul 2012 — He presented to the role 1 facility with three days of pain under the left big toe joint, worse when pushing off and when walking on rocky ground, which began during a week of greatly increased patrolling. Examination showed focal tenderness over the medial sesamoid, pain on passive dorsiflexion of the big toe and mild swelling. Weight 97 kg, height 1.78 m, BMI 30.6. "tender medial sesamoid, L foot"
- 20 Nov 2012 — After return to Australia, MRI of the left forefoot showed marrow oedema of the medial and lateral sesamoids with surrounding soft tissue inflammation and no fracture. A sports physician diagnosed left sesamoiditis and supplied a dancer's pad, orthoses and a rigid-soled shoe. Symptoms settled partially. "MRI sesamoid oedema, no fracture"
- 28 Sep 2015 — On warlike service in Iraq he presented with marked worsening of left forefoot pain after a month of daily running and range work, a heavy landing on the left forefoot during a training jump on 04 Sep 2015 and a doubling of his training load. His orthoses had worn out and no podiatry was available. BMI 31.4. "forefoot pain markedly worse"
- 14 Dec 2015 — After return to Australia, MRI showed a fracture of the medial sesamoid with persisting marrow oedema of both sesamoids, a progression from the 2012 study. An orthopaedic surgeon managed him in a walking boot and later performed a partial medial sesamoidectomy on 22 Jun 2016. He was medically discharged on 18 Oct 2018. "medial sesamoid fracture on MRI"
Symptoms
At onset the veteran had pain beneath the left big toe joint, worse when pushing off, running, jumping and walking on uneven ground, with swelling and tenderness over the medial sesamoid. After onset the pain persisted with load carriage and running, and from September 2015 it became constant, with pain at rest and a limp.
He now reports daily pain under the left big toe joint, inability to run or jump, pain after walking more than 30 minutes and difficulty wearing firm-soled shoes.
Imaging
- 02 Jun 2012 — X-ray left foot (role 2 facility, Afghanistan): "No fracture. Bipartite lateral sesamoid. Mild hallux valgus with early dorsal osteophyte at the first metatarsophalangeal joint."
- 20 Nov 2012 — MRI left forefoot: "Marrow oedema of the medial and lateral sesamoids with surrounding soft tissue inflammation and flexor hallucis brevis tendinosis. No fracture or osteonecrosis."
- 14 Dec 2015 — MRI left forefoot: "Transverse fracture of the medial sesamoid with persisting marrow oedema of both sesamoids. Progression since 20 November 2012."
Onset Date
The most likely date of onset of this condition is 18 Jul 2012.
At that date the veteran was on warlike service in Afghanistan as an infantry section commander, conducting long dismounted patrols from a forward patrol base. From 10 July 2012 his patrol hours had more than doubled during a clearance operation, and he had landed heavily on his left forefoot on 02 June 2012.
This date is appropriate because the medical review of 08 Jul 2012 recorded no foot pain, and he first presented with the symptoms on 21 Jul 2012, three days after they began. It falls within continuous full-time service.
For the running and weight bearing causes, the 4 weeks before onset run from 20 Jun 2012 to 18 Jul 2012; he ran about 45 km a week and patrolled more than 15 hours a week under load in that period. For the increase in activity, the 1 week before onset runs from 11 Jul 2012 to 18 Jul 2012, within the surge in patrol hours from 10 Jul 2012. For the direct trauma cause, the 3 months before onset run from 18 Apr 2012 to 18 Jul 2012, and the landing injury of 02 Jun 2012 falls within it. For the footwear cause, he wore issued rigid-soled combat boots for at least 10 hours a day throughout the 6 months before onset, from 18 Jan 2012 to 18 Jul 2012. The pes cavus, hallux limitus, hallux valgus, reduced ankle dorsiflexion, spondyloarthropathy and a BMI above 30 were each present on 18 Jul 2012.
For the worsening causes, the documented clinical worsening is on 25 Sep 2015, confirmed by MRI on 14 Dec 2015. The 4 weeks before it run from 28 Aug 2015 to 25 Sep 2015, the 1 week before it from 18 Sep 2015 to 25 Sep 2015, and the 3 months before it from 25 Jun 2015 to 25 Sep 2015, containing the landing injury of 04 Sep 2015.
1. What is the formal diagnosis of the condition claimed above?
The formal diagnosis is Left Sesamoiditis of the first metatarsophalangeal joint (ICD-10-AM M25.87), complicated by a stress fracture of the medial sesamoid. No Statement of Principles has been determined for sesamoiditis.
Sesamoiditis is a painful inflammatory and stress-related condition of the two small sesamoid bones within the flexor hallucis brevis tendon beneath the head of the first metatarsal, and of the surrounding tendon and soft tissue. The sesamoids carry a large share of body weight during push-off, running and landing. Repetitive or excessive forefoot loading, direct impact, a high-arched or stiff foot, rigid footwear and inflammatory arthritis cause marrow oedema and pain, and continued loading can progress to stress fracture, fragmentation or osteonecrosis.
The condition followed a forefoot landing injury and heavy patrol, running and parachuting loads in rigid boots on a high-arched, stiff left foot on warlike service in Afghanistan. It began on 18 July 2012, was confirmed on MRI on 20 November 2012 and worsened in Iraq in September 2015.
2. For each diagnosis identified, please also provide the following dates:
When did the veteran first experience symptoms attributable to this condition?
18 July 2012.
When did the veteran first present to a health / medical provider for this condition?
21 July 2012.
When was the condition confirmed / formally diagnosed?
20 November 2012.
When did the veteran first present to you (or your practice) for this condition?
03 April 2025.
3. How was this diagnosis confirmed? i.e. what were the key symptoms and signs, investigation results, specialist opinions?
The diagnosis was confirmed by MRI on 20 November 2012, which showed marrow oedema of the medial and lateral sesamoids with surrounding soft tissue inflammation and no fracture, in keeping with sesamoiditis. X-ray on 02 June 2012 had excluded an acute fracture and showed a bipartite lateral sesamoid, which was distinguished from a fracture on MRI.
The clinical picture was consistent: pain beneath the first metatarsal head on push-off, focal tenderness over the medial sesamoid and pain on passive dorsiflexion of the big toe. A sports physician confirmed the diagnosis on 20 November 2012. Repeat MRI on 14 December 2015 confirmed worsening with a medial sesamoid fracture.
4. What do you consider to be the cause(s) of the condition in this veteran? Give consideration to constitutional and common risk factors, pre-existing injuries or diseases, and occupational or lifestyle risks, as well as direct causative mechanisms.
No Statement of Principles has been determined by the Repatriation Medical Authority for sesamoiditis. The claim is therefore decided on the sound medical-scientific evidence of what causes and worsens the condition, without the limits a Statement of Principles would impose, and the causes below are those well recognised in the medical literature.
Legislation: the clinical onset of this condition was on 18 July 2012, after 1 July 2004, during continuous full-time service, including warlike service in Afghanistan, where it began, and in Iraq in 2015, where it worsened. This is a Military Rehabilitation and Compensation Act 2004 (MRCA) claim. Each cause must be related to the person's service. Under the beneficial approach required by the legislation, the absence of documentation does not mean that an event or exposure did not occur: lack of evidence is not evidence of lack.
Recognised causes on the medical-scientific evidence (no Statement of Principles)
Causative factors
Cause 1: running or jogging an average of at least 30 kilometres per week for at least the 4 weeks before the clinical onset of sesamoiditis; — MET
- The veteran ran an average of about 45 kilometres a week on the patrol base perimeter and track in the 4 weeks before onset, from 20 June 2012 to 18 July 2012, to maintain the fitness standard required of a paratrooper section commander on warlike service in Afghanistan. Running places repeated loads of two to three times body weight through the sesamoids at each push-off.
Cause 2: undertaking weight bearing activity involving repetitive loading of the forefoot, such as marching, patrolling, jumping or parachute landing, for at least 6 hours per week for at least the 4 weeks before the clinical onset of sesamoiditis; — MET
- In the 4 weeks before onset he patrolled on foot more than 15 hours a week carrying about 40 kilograms over steep, rocky ground, with repeated scrambling, climbing and jumping from walls, on warlike service in Afghanistan. Load carriage and climbing force the big toe into dorsiflexion under load and concentrate pressure beneath the first metatarsal head.
Cause 3: increasing the frequency, duration or intensity of weight bearing activity involving the forefoot by at least 100 percent within the 1 week before the clinical onset of sesamoiditis; — MET
- From 10 July 2012, during a clearance operation in Afghanistan, his daily patrol time rose from about 3 hours to about 8 hours under load, an increase of more than 100 percent, within the 1 week before onset on 18 July 2012. A sudden rise in load without time for bone adaptation is the commonest trigger of sesamoid stress reaction.
Cause 4: having direct trauma to the plantar aspect of the first metatarsophalangeal joint of the affected foot within the 3 months before the clinical onset of sesamoiditis; — MET
- On 02 June 2012 he landed heavily on the ball of his left foot when jumping about 2 metres from a compound wall under a 40 kilogram load on warlike service in Afghanistan. The medic recorded bruising beneath the first metatarsal head, and X-ray excluded a fracture. This was within the 3 months before onset, from 18 April 2012 to 18 July 2012.
Cause 5: having pes cavus or a plantarflexed first ray of the affected foot at the time of the clinical onset of sesamoiditis; — MET
- A podiatrist recorded a left pes cavus foot with a rigid plantarflexed first ray on 14 March 2011, and this was present at onset. A high-arched foot with a plantarflexed first ray transmits a disproportionate share of forefoot load through the sesamoids.
Cause 6: wearing rigid-soled or poorly cushioned footwear while weight bearing for at least 8 hours per day for at least the 6 months before the clinical onset of sesamoiditis; — MET
- He wore issued combat boots with a rigid, thin forefoot sole and no cushioning insert for at least 10 hours a day throughout the 6 months before onset, from 18 January 2012 to 18 July 2012, including on deployment, because the orthoses recommended in March 2011 were never supplied.
Cause 7: having hallux limitus, hallux rigidus or hallux valgus of the affected foot at the time of the clinical onset of sesamoiditis; — MET
- Early left hallux limitus, with first metatarsophalangeal dorsiflexion of 40 degrees, and a hallux valgus of 18 degrees were recorded on 14 March 2011 and on X-ray on 02 June 2012, and were present at onset. Both alter the position and loading of the sesamoids beneath the metatarsal head.
Cause 8: having reduced ankle dorsiflexion or tightness of the gastrocnemius-soleus complex on the affected side at the time of the clinical onset of sesamoiditis; — MET
- Tight calf muscles with ankle dorsiflexion of 5 degrees on the left were recorded on 14 March 2011 and at presentation on 21 July 2012. Restricted ankle dorsiflexion causes early heel lift and prolonged forefoot loading during gait and load carriage.
Cause 9: having an inflammatory arthritis, including a spondyloarthropathy, reactive arthritis or gout, involving the affected foot at the time of the clinical onset of sesamoiditis; — MET
- Reactive arthritis involving the left first metatarsophalangeal joint followed Campylobacter gastroenteritis contracted on warlike service in Afghanistan in April 2012, in an HLA-B27 positive man, and was later classified as a peripheral spondyloarthropathy. It was active at onset. Enthesitis of the flexor hallucis brevis attachment is a recognised feature of spondyloarthropathy.
Cause 10: having a Body Mass Index of 30 or greater at the time of the clinical onset of sesamoiditis; — MET
- The veteran weighed 97 kg at a height of 1.78 m at presentation on 21 July 2012, a BMI of 30.6, at onset. A higher body mass increases the load through the forefoot at every step, particularly when combined with a 40 kilogram patrol load.
Worsening factors
Worsening 1: undertaking running or weight bearing activity involving repetitive loading of the forefoot for at least 6 hours per week for at least the 4 weeks before the clinical worsening of sesamoiditis; — MET
- On warlike service in Iraq the veteran ran about 40 kilometres a week and spent more than 10 hours a week on range work, patrol rehearsals and parachute training in the 4 weeks before the worsening, from 28 August 2015 to 25 September 2015.
Worsening 2: increasing the frequency, duration or intensity of weight bearing activity involving the forefoot by at least 100 percent within the 1 week before the clinical worsening of sesamoiditis; — MET
- From 18 September 2015 his training load in Iraq rose from about 2 hours to about 5 hours a day for a mission rehearsal period, within the 1 week before the worsening on 25 September 2015.
Worsening 3: having direct trauma to the plantar aspect of the first metatarsophalangeal joint of the affected foot within the 3 months before the clinical worsening of sesamoiditis; — MET
- On 04 September 2015 he landed heavily on the left forefoot during a training parachute descent in Iraq, within the 3 months before the worsening. MRI on 14 December 2015 showed a fracture of the medial sesamoid.
Worsening 4: having a Body Mass Index of 30 or greater at the time of the clinical worsening of sesamoiditis; — MET
- His BMI was 31.4 at presentation on 28 September 2015, at the time of the worsening on warlike service in Iraq.
Worsening 5: inability to obtain appropriate clinical management for sesamoiditis. — MET
- On warlike service in Iraq from April to November 2015 the veteran's orthoses had worn out and no podiatry, replacement orthoses, imaging or sports medicine review was available. He continued full training and parachuting duties without offloading, and the sesamoiditis progressed to a medial sesamoid fracture. Under Brew v Repatriation Commission (1999) this is an inability to obtain appropriate clinical management.
The % contribution of the causes is 100% and significant.
Sequelae
The left sesamoiditis is in part a sequela of the veteran's reactive arthritis and peripheral spondyloarthropathy, which followed gastroenteritis contracted on warlike service in Afghanistan in 2012, and of the forefoot landing injury of 02 June 2012.
Unintended Consequence
Not applicable on the present evidence. No treatment provided by the Commonwealth caused or worsened the condition; the worsening followed the absence of replacement orthoses and podiatry care.
Inability to Attain Appropriate Medical Management
MET. On warlike service in Iraq from April to November 2015 the veteran's orthoses had worn out and no podiatry, replacement orthoses, offloading footwear, imaging or sports medicine review was available, so he continued running, range work and parachuting on an untreated sesamoiditis. MRI on 14 December 2015 showed progression from sesamoid marrow oedema to a fracture of the medial sesamoid. Applying the objective and subjective tests in Brew v Repatriation Commission (Full Federal Court, 10 September 1999, Merkel J), operational constraints that prevent appropriate treatment amount to an inability to obtain appropriate clinical management.
5. Please provide a Health Summary and a medication / prescribing history.
See attached report.
References
- 14 Mar 2011, Podiatry assessment, Podiatrist
- 10 Apr 2012, Outpatient health record, Medical Officer, Afghanistan
- 02 Jun 2012, X-ray left foot, Role 2 facility, Afghanistan
- 08 Jul 2012, Outpatient health record, Medical Officer, Afghanistan
- 21 Jul 2012, Outpatient health record, Medical Officer, Role 1 facility, Afghanistan
- 20 Nov 2012, MRI left forefoot and sports medicine consultation, Sports physician
- 28 Sep 2015, Outpatient health record, Medical Officer, Iraq
- 14 Dec 2015, MRI left forefoot and orthopaedic consultation, Orthopaedic surgeon
- 22 Jun 2016, Operation report, Orthopaedic surgeon
