Left Thigh - Meralgia Paraesthetica — DVA claim example

Diagnostic Assessment — Left Thigh - Meralgia Paraesthetica

Example 1 of 1 · fictitious patient (Veteran AI)

Diagnostic Assessment

Left Thigh - Meralgia Paraesthetica

No Statement of Principles applies to this condition (non-SOP claim).

ADF History

Veteran AI, date of birth 22 September 1987, Australian Army, Rifleman (Infantry), enlisted 08 February 2006, medically discharged 14 November 2019. Operational service: Afghanistan, 05 February 2012 to 10 October 2012 (warlike); Middle East Area of Operations (Iraq), 01 April 2017 to 20 November 2017 (warlike).

Occupational History

An infantry rifleman patrols on foot and in protected vehicles for long periods carrying body armour, a webbing or load-bearing belt with magazines, water and equipment, and a patrol pack. Combined loads of 35 to 55 kilograms are routine, much of the weight bearing on the iliac crests through belts, hip pads and the lower edge of the armour.

The trade involves prolonged marching with repeated hip extension, climbing and jumping from walls and vehicles, and long periods seated in cramped vehicle seats with the hips flexed against the armour and belt. Falls, blunt injuries to the pelvis and limbs, and weight fluctuation between deployments and garrison life are common.

History

Veteran AI, an infantry rifleman in the Australian Army, developed meralgia paraesthetica of the left thigh on 07 May 2012 during warlike service in Afghanistan, after months of foot patrolling in body armour and a loaded belt, a fall onto the left hip with an iliacus haematoma, and an earlier left iliac crest bone graft. The condition worsened in August 2017 while he wore heavier armour on warlike service in Iraq.

Timeline

• 16 Jun 2011 — An orthopaedic hand surgeon fixed a non-union of the left scaphoid, fractured on a field exercise in 2010, using a screw and a cancellous bone graft harvested from the left anterior iliac crest. The graft was taken through an incision 2 cm behind the anterior superior iliac spine. Post-operative notes recorded tenderness at the donor site but normal thigh sensation. "left iliac crest graft harvested"
• 12 Jan 2012 — At the pre-deployment medical examination his weight was 102 kg and height 1.82 m, a BMI of 30.8, having gained 11 kg, from 91 kg, during his post-operative restriction from field duties in the second half of 2011. Sensation in both thighs was normal. He was assessed fit to deploy. "BMI 30.8, fit to deploy"
• 21 Apr 2012 — On a foot patrol in Afghanistan he fell about 2 metres from a compound wall, landing on his left hip on a magazine pouch on his belt. The regimental aid post recorded bruising and tenderness over the left anterior superior iliac spine. Sensation in the lateral thigh was intact. Ultrasound at the role 2 facility two days later showed a 4 cm haematoma in the left iliacus muscle. "fall onto left ASIS, haematoma"
• 09 May 2012 — He presented to the regimental aid post with burning pain, tingling and numbness over the outer left thigh that began on 07 May 2012. Symptoms were worse after long patrols and when his belt and armour were tightened, and eased when he removed them. He was tender just medial to the left anterior superior iliac spine with a positive pelvic compression test. Power, reflexes and the femoral nerve territory were normal. "burning numb lateral left thigh"
• 18 Dec 2012 — Back in Australia a neurologist performed nerve conduction studies. The left lateral femoral cutaneous nerve sensory response was absent, with a normal right response and normal femoral nerve and lumbar root studies. The neurologist diagnosed left meralgia paraesthetica. A diagnostic lateral femoral cutaneous nerve block on 22 Jan 2013 gave complete temporary relief. "absent left LFCN response"
• 30 Aug 2017 — On warlike service in Iraq he reported to the role 2 facility that the numbness had spread to cover most of the outer thigh, with constant burning pain and night waking. He had been wearing heavier ballistic plates and a fully loaded belt for force protection duties of 10 to 12 hours a day since April. Weight 110 kg. Pregabalin was started. "numbness spread, burning pain constant"
• 05 Dec 2017 — After return to Australia ultrasound showed swelling of the left lateral femoral cutaneous nerve at the inguinal ligament, larger than in 2013. A pain specialist performed an ultrasound-guided block with corticosteroid, and pulsed radiofrequency treatment followed on 14 Jun 2018 with partial relief. "nerve swollen, block and PRF"

Symptoms

At onset the veteran had burning pain, pins and needles and numbness over the outer aspect of the left thigh, aggravated by prolonged walking, standing and wearing his belt and body armour, and relieved by removing them and sitting with the hip flexed. There was no weakness.

Since the 2017 worsening the numbness covers most of the anterolateral thigh, with constant burning and hypersensitivity to clothing and touch, night waking, and pain after standing or walking for more than 30 minutes. He cannot tolerate a belt or tight clothing at the waist.

Imaging

• 23 Apr 2012 — Ultrasound left hip and pelvis: "4 cm haematoma in the left iliacus muscle adjacent to the anterior superior iliac spine. No fracture of the visible bony margins."
• 22 Jan 2013 — MRI lumbar spine: "No disc protrusion or nerve root compression. Normal conus."
• 22 Jan 2013 — Ultrasound left lateral femoral cutaneous nerve: "Mild swelling of the nerve as it passes beneath the inguinal ligament, cross-sectional area 6 mm2. Resolved iliacus haematoma."
• 05 Dec 2017 — Ultrasound left lateral femoral cutaneous nerve: "Increased swelling of the nerve at the inguinal ligament, cross-sectional area 9 mm2, with a hypoechoic segment."

Onset Date

The most likely date of onset of this condition is 07 May 2012.

At that date the veteran was on warlike service in Afghanistan with an infantry battalion task group, conducting daily foot patrols in body armour with a loaded webbing belt and patrol pack, and vehicle patrols in protected mobility vehicles.

This date is appropriate because the regimental aid post examination after his fall on 21 Apr 2012 recorded intact sensation in the lateral thigh, and he first presented with the symptoms on 09 May 2012, reporting that they began two days earlier. It falls within his warlike deployment.

For the belt and armour, hip extension and vehicle sitting causes, the 3 months before onset run from 07 Feb 2012 to 07 May 2012; he arrived in Afghanistan on 05 Feb 2012 and patrolled daily in armour and a loaded belt throughout that period. For the load carriage cause, the 6 months before onset run from 07 Nov 2011 to 07 May 2012, and the patrol loads from February to May filled it. For the weight gain and bone graft causes, the 12 months before onset run from 07 May 2011 to 07 May 2012 and include the graft harvest of 16 Jun 2011. For the trauma cause, the 3 months before onset include the fall of 21 Apr 2012. Obesity and the iliacus haematoma were present on 07 May 2012.

For the worsening, the condition began on 07 May 2012 and worsened as documented on 30 Aug 2017. The 3 months before the worsening run from 30 May 2017 to 30 Aug 2017, during which he wore heavier armour and a loaded belt and stood or walked on sentry and perimeter duties for 10 to 12 hours a day on warlike service in Iraq, and the 12 months before the worsening, from 30 Aug 2016 to 30 Aug 2017, include his weight rise from 104 kg to 110 kg.

1. What is the formal diagnosis of the condition claimed above?

The formal diagnosis is Meralgia Paraesthetica of the left thigh (ICD-10 G57.1), a compressive mononeuropathy of the left lateral femoral cutaneous nerve.

Meralgia paraesthetica is a sensory neuropathy of the lateral femoral cutaneous nerve, which arises from the L2 and L3 roots and leaves the pelvis by passing under or through the inguinal ligament just medial to the anterior superior iliac spine. Compression, stretch or injury at that point causes burning pain, tingling, numbness and hypersensitivity over the anterolateral thigh, without weakness. Recognised causes include external compression from belts, harnesses and body armour, load carriage, obesity, trauma and haematoma near the anterior superior iliac spine, surgery at the iliac crest, and prolonged hip extension or flexion. Most cases settle once the compression is removed, but persistent compression can produce chronic pain.

The condition followed a left iliac crest bone graft in 2011 and months of armour and load carriage with a fall onto the hip in Afghanistan in 2012. It began on 07 May 2012, was confirmed on nerve conduction studies on 18 December 2012 and worsened in August 2017 on further warlike service.

2. For each diagnosis identified, please also provide the following dates:

When did the veteran first experience symptoms attributable to this condition?

07 May 2012.

When did the veteran first present to a health / medical provider for this condition?

09 May 2012.

When was the condition confirmed / formally diagnosed?

18 December 2012.

When did the veteran first present to you (or your practice) for this condition?

07 April 2025.

3. How was this diagnosis confirmed? i.e. what were the key symptoms and signs, investigation results, specialist opinions?

The diagnosis was made clinically on 09 May 2012 from the typical distribution of burning pain and numbness over the outer left thigh, tenderness medial to the anterior superior iliac spine, a positive pelvic compression test and normal motor and reflex examination. It was confirmed by a neurologist on 18 December 2012, when nerve conduction studies showed an absent left lateral femoral cutaneous nerve sensory response with a normal right side and normal femoral nerve and lumbar root studies.

A diagnostic nerve block on 22 January 2013 gave complete temporary relief, and MRI of the lumbar spine excluded an upper lumbar radiculopathy. Ultrasound showed swelling of the nerve at the inguinal ligament in 2013 and increased swelling on 05 December 2017, confirming the documented worsening.

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 meralgia paraesthetica. The claim is therefore decided on the sound medical-scientific evidence of what causes the condition, without the limits a Statement of Principles would impose. The recognised causes below are drawn from the medical literature on lateral femoral cutaneous nerve entrapment, and each is set out in the style of a Statement of Principles factor and applied to the veteran's service.

Legislation: the clinical onset of this condition was on 07 May 2012, after 1 July 2004, during warlike service in Afghanistan. This is a Military Rehabilitation and Compensation Act 2004 (MRCA) claim. The reasonable hypothesis standard applies to the veteran's operational (warlike) service in Afghanistan in 2012 and Iraq in 2017, and the balance of probabilities standard to his peacetime service. 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: wearing a tightly fitted belt, harness, webbing or body armour that applies pressure over or just medial to the anterior superior iliac spine for at least 4 hours per day on at least 4 days per week for at least the 3 months before the clinical onset of meralgia paraesthetica; — MET

- From arrival in Afghanistan on 05 February 2012 the veteran patrolled daily in body armour with a webbing belt carrying six magazines, grenades, water and a first aid kit, tightened so that the lower edge of the armour and the belt sat across both anterior superior iliac spines. Patrol records show 6 to 8 hours a day on at least six days a week throughout the 3 months before onset, from 07 February 2012 to 07 May 2012. The symptoms eased when he removed the belt and armour.

Cause 2: carrying a load of at least 20 kilograms supported by a hip belt or load-bearing belt for a cumulative total of at least 100 hours within the 6 months before the clinical onset of meralgia paraesthetica; — MET

- On foot patrols in Afghanistan the veteran carried a patrol pack of 30 to 40 kilograms with a padded hip belt, in addition to his armour and webbing. Between February and May 2012 he completed more than 60 patrols of 4 to 8 hours, well over 100 hours of load carriage within the 6 months before onset, from 07 November 2011 to 07 May 2012.

Cause 3: being obese at the time of the clinical onset of meralgia paraesthetica; — MET

- At the pre-deployment medical examination on 12 January 2012 the veteran weighed 102 kg at a height of 1.82 m, a BMI of 30.8, after weight gain during his post-operative restriction from field duties in 2011. His weight was unchanged at the role 2 review in May 2012. A protuberant lower abdomen increases the angulation and pressure on the nerve at the inguinal ligament and pushes belt pressure onto it.

Cause 4: having blunt trauma to the region of the anterior superior iliac spine or the lateral part of the inguinal ligament on the affected side within the 3 months before the clinical onset of meralgia paraesthetica; — MET

- On 21 April 2012, during a foot patrol on warlike service, the veteran fell about 2 metres from a compound wall and landed on his left hip on a magazine pouch, with bruising and tenderness over the left anterior superior iliac spine recorded at the regimental aid post. This was 16 days before onset, within the 3 months before onset.

Cause 5: undergoing harvest of a bone graft from the anterior iliac crest on the affected side within the 12 months before the clinical onset of meralgia paraesthetica; — MET

- A cancellous bone graft was harvested from the left anterior iliac crest, 2 cm behind the anterior superior iliac spine, on 16 June 2011 to treat a non-union of a scaphoid fracture sustained on a field exercise. This is within the 12 months before onset, from 07 May 2011 to 07 May 2012. Scarring at the donor site tethers the nerve where it crosses the iliac crest.

Cause 6: having a haematoma, mass or other space-occupying lesion in the iliacus muscle, retroperitoneum or pelvis along the course of the lateral femoral cutaneous nerve at the time of the clinical onset of meralgia paraesthetica; — MET

- Ultrasound on 23 April 2012 showed a 4 cm haematoma in the left iliacus muscle from the fall on warlike service two days earlier. The nerve runs across the surface of the iliacus, and the haematoma was still present, though reducing, at onset on 07 May 2012. Ultrasound on 22 January 2013 confirmed it had resolved.

Cause 7: undertaking prolonged walking, marching or standing with repeated or sustained hip extension for at least 4 hours per day on at least 4 days per week for at least the 3 months before the clinical onset of meralgia paraesthetica; — MET

- Daily dismounted patrols in Afghanistan involved walking under load for 4 to 8 hours over broken ground and through irrigated fields, on at least six days a week, throughout the 3 months before onset, from 07 February 2012 to 07 May 2012. Hip extension stretches the nerve over the inguinal ligament.

Cause 8: sitting in a confined position with the hips flexed while wearing equipment that compresses the groin or anterior superior iliac spine for at least 3 hours per day on at least 3 days per week for at least the 3 months before the clinical onset of meralgia paraesthetica; — MET

- On vehicle patrols in protected mobility vehicles the veteran sat for 3 to 6 hours at a time in a cramped seat in full body armour, with the lower edge of the armour and the belt pressed into both groins. This occurred on at least three days a week from February to May 2012, throughout the 3 months before onset.

Cause 9: gaining at least 10 kilograms in body weight within the 12 months before the clinical onset of meralgia paraesthetica; — MET

- The veteran weighed 91 kg at his periodic health examination on 02 May 2011 and 102 kg on 12 January 2012, a gain of 11 kilograms after the scaphoid surgery of 16 June 2011 kept him off running and field training for six months. The gain falls within the 12 months before onset, from 07 May 2011 to 07 May 2012. Rapid weight gain increases abdominal girth and the downward pressure of belts and armour onto the inguinal ligament.

Worsening factors

Worsening 1: wearing a tightly fitted belt, harness, webbing or body armour that applies pressure over or just medial to the anterior superior iliac spine for at least 4 hours per day on at least 4 days per week for at least the 3 months before the clinical worsening of meralgia paraesthetica; — MET

- On warlike service in Iraq from 01 April 2017 the veteran wore heavier ballistic plates and a fully loaded belt for force protection and guard duties of 10 to 12 hours a day, on six or seven days a week, throughout the 3 months before the documented worsening, from 30 May 2017 to 30 August 2017. The numbness spread and the pain became constant.

Worsening 2: carrying a load of at least 20 kilograms supported by a hip belt or load-bearing belt for a cumulative total of at least 100 hours within the 6 months before the clinical worsening of meralgia paraesthetica; — MET

- In Iraq his armour, belt and personal equipment weighed 28 to 32 kilograms, with the belt load supported on the iliac crests. He carried it for more than 900 hours between April and August 2017, within the 6 months before the worsening, from 28 February 2017 to 30 August 2017.

Worsening 3: undertaking prolonged walking, marching or standing with repeated or sustained hip extension for at least 4 hours per day on at least 4 days per week for at least the 3 months before the clinical worsening of meralgia paraesthetica; — MET

- Force protection duties in Iraq involved standing sentry in towers and at entry control points and walking perimeter patrols for 10 to 12 hours a day, on six or seven days a week, throughout the 3 months before the worsening, from 30 May 2017 to 30 August 2017. The burning pain was recorded as worst at the end of each sentry shift.

Worsening 4: gaining at least 5 kilograms in body weight, or being obese, within the 12 months before the clinical worsening of meralgia paraesthetica; — MET

- The veteran weighed 104 kg at his periodic health examination on 14 September 2016 and 110 kg at the role 2 review on 30 August 2017, a gain of 6 kilograms within the 12 months before the worsening, and his BMI of 33.2 was in the obese range. The weight gain followed reduced activity while his symptoms limited running.

Worsening 5: inability to obtain appropriate clinical management for meralgia paraesthetica. — MET

- In Iraq in 2017 there was no access to a neurologist, ultrasound-guided nerve block or alternative body armour, and the veteran was required to keep wearing the armour and belt that compressed the nerve for 10 to 12 hours a day for almost five months. The condition worsened during that time. 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

Meralgia paraesthetica is a sequela of the veteran's accepted left scaphoid fracture, through the iliac crest bone graft used to treat its non-union, and of the fall onto the left hip on warlike service in 2012 with its iliacus haematoma. The chronic neuropathic pain has in turn disturbed his sleep and limited his walking, standing and ability to wear load-bearing equipment, contributing to his medical discharge.

Unintended Consequence

Met. The meralgia paraesthetica is in part an unintended consequence of the left iliac crest bone graft harvest performed on 16 June 2011 as Defence-funded treatment of a service-related scaphoid non-union, in which scarring at the donor site tethers the lateral femoral cutaneous nerve (section 6A of the DRCA and the equivalent provisions of the MRCA).

Inability to Attain Appropriate Medical Management

MET. After onset in May 2012 the veteran remained on warlike service in Afghanistan for a further five months without access to nerve conduction studies or a neurologist, and he was required to keep wearing the armour and belt that caused the compression; the diagnosis was not confirmed until 18 December 2012. In Iraq in 2017 there was again no access to specialist care, nerve block or modified armour, and the condition worsened, with the area of numbness enlarging and the pain becoming constant. Applying the objective and subjective tests in Brew v Repatriation Commission (Full Federal Court, 10 September 1999, Merkel J), operational constraints that prevent the removal of the cause and the delivery of 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

1. 02 May 2011, Periodic health examination, Medical Officer, Garrison health centre
2. 16 Jun 2011, Operation report, Orthopaedic hand surgeon
3. 12 Jan 2012, Pre-deployment medical examination, Medical Officer
4. 21 Apr 2012, Regimental aid post record, Medical Officer, Afghanistan
5. 23 Apr 2012, Ultrasound left hip and pelvis, Role 2 facility, Afghanistan
6. 09 May 2012, Regimental aid post record, Medical Officer, Afghanistan
7. 18 Dec 2012, Nerve conduction study report, Neurologist
8. 22 Jan 2013, MRI lumbar spine and ultrasound, Radiologist
9. 22 Jan 2013, Diagnostic nerve block, Pain specialist
10. 14 Sep 2016, Periodic health examination, Medical Officer, Garrison health centre
11. 30 Aug 2017, Role 2 consultation, Medical Officer, Iraq
12. 05 Dec 2017, Ultrasound and ultrasound-guided nerve block, Pain specialist
13. 14 Jun 2018, Pulsed radiofrequency procedure report, Pain specialist
14. Medical-scientific literature on the causes of lateral femoral cutaneous nerve entrapment (meralgia paraesthetica)