Diagnostic Assessment — Left Ankle - Osteochondral Lesion of the Talus
Example 1 of 1 · fictitious patient (Veteran BK)
Diagnostic Assessment
Left Ankle - Osteochondral Lesion of the Talus
BOP Code: 22 of 2019 (Acute Articular Cartilage Tear)
RH Code: 21 of 2019 (Acute Articular Cartilage Tear)
ADF History
Veteran BK, date of birth 27 September 1988, Australian Army, Rifleman (parachute-qualified infantry), enlisted 05 February 2007, medically discharged 18 November 2020. Operational service: Afghanistan, 05 February 2010 to 20 September 2010 (warlike); Middle East Area of Operations (Iraq), 10 October 2017 to 02 June 2018 (warlike).
Occupational History
Infantry soldiers patrol on foot over rough and uneven ground carrying loads of 30 to 45 kilograms, run, jump from vehicles and walls and conduct fast roping. Parachute-qualified soldiers also make static-line descents in which landing forces of several times body weight pass through the ankles, often at night and onto uneven drop zones.
Ankle sprains are among the most common injuries in the trade, and repeated sprains cause chronic lateral ligament instability, anterolateral impingement and damage to the articular cartilage of the talus.
History
Veteran BK, a parachute-qualified infantry rifleman in the Australian Army, developed chronic left ankle instability after an inversion injury on warlike service in Afghanistan on 17 July 2010, and sustained an acute osteochondral tear of the lateral talar dome during arthroscopic surgery for that instability on 14 March 2014. The lesion enlarged and became unstable during his 2017 to 2018 deployment to the Middle East, when the recommended surgery could not be obtained.
Timeline
- 17 Jul 2010 — On a foot patrol during warlike service in Afghanistan the veteran stepped into an irrigation ditch carrying about 40 kg and sustained a severe inversion injury of the left ankle. The regimental aid post recorded swelling and bruising over the lateral ankle and tenderness over the anterior talofibular ligament. He was strapped and continued patrolling after five days of restricted duties. "inversion injury, ATFL tender"
- 22 Aug 2012 — After three further sprains of the left ankle in parachute landings in 2011 and 2012, the veteran reported giving way on uneven ground and anterolateral ankle pain on squatting. Examination showed a positive anterior drawer test and anterolateral tenderness. He was referred to an orthopaedic surgeon. "recurrent giving way, drawer positive"
- 20 Feb 2014 — Pre-operative MRI showed a chronic tear of the anterior talofibular ligament, attenuation of the calcaneofibular ligament and anterolateral synovitis, with intact articular cartilage over the talar dome and no marrow oedema. An orthopaedic surgeon recommended arthroscopy and lateral ligament reconstruction. "talar dome cartilage intact"
- 14 Mar 2014 — Left ankle arthroscopy with debridement of anterolateral impingement and modified Broström reconstruction with two suture anchors was performed. The operation note records a tight joint requiring increased invasive distraction, repeated stress testing under anaesthesia and difficult instrument passage through the anterolateral portal. From recovery that afternoon the veteran reported deep pain over the lateral ankle, more severe than expected. "tight joint, increased distraction"
- 05 May 2014 — MRI for persisting deep ankle pain, catching and swelling showed an acute osteochondral lesion of the lateral talar dome measuring 9 by 7 mm with a partially detached cartilage flap and surrounding marrow oedema. The orthopaedic surgeon diagnosed an acute osteochondral tear of the talus sustained at surgery and recommended debridement and microfracture. "acute lateral talar dome OCL"
- 12 Mar 2018 — During warlike service in the Middle East, where the recommended surgery could not be performed, the veteran reported increasing ankle pain, locking and swelling after patrols with 40 kg loads. MRI at a coalition facility showed the lesion enlarged to 14 by 10 mm, with an unstable fragment and a 6 mm subchondral cyst. Surgery was scheduled for his return from deployment. "lesion enlarged, unstable fragment"
- 16 Jul 2018 — Arthroscopic debridement, fragment excision and microfracture of the lateral talar dome lesion were performed. Afterwards he remained unable to run or carry loads. "debridement and microfracture"
Symptoms
At onset the veteran had deep, aching pain in the lateral left ankle with tenderness over the anterolateral joint line, swelling after activity, catching and a sensation of the ankle locking. Pain was worse on weight bearing on uneven ground and on stairs.
He now has persisting ankle pain and stiffness after microfracture, swelling after walking more than 2 kilometres, inability to run or jump, and early degenerative change in the ankle joint.
Imaging
- 20 Feb 2014 — MRI left ankle: "Chronic tear of the anterior talofibular ligament and attenuated calcaneofibular ligament with anterolateral synovitis. Talar dome articular cartilage intact. No marrow oedema."
- 05 May 2014 — MRI left ankle: "Acute osteochondral lesion of the lateral talar dome, 9 x 7 mm, with a partially detached cartilage flap and surrounding bone marrow oedema."
- 12 Mar 2018 — MRI left ankle: "Enlarged lateral talar dome osteochondral lesion, 14 x 10 mm, with fluid undercutting an unstable fragment and a 6 mm subchondral cyst."
- 02 Jul 2018 — CT left ankle: "Lateral talar dome osteochondral defect with a subchondral cyst and a loose osteochondral fragment. Early anterior tibiotalar osteophytes."
Onset Date
The most likely date of onset of this condition is 14 Mar 2014.
At that date the veteran was serving full time as an infantry rifleman and underwent left ankle arthroscopy and lateral ligament reconstruction for chronic instability that followed his 2010 warlike-service inversion injury and later parachuting sprains. During the operation the ankle was subjected to invasive distraction and forced stress testing, and instruments passed with difficulty across the lateral talar dome. From recovery that afternoon he had deep lateral ankle pain.
This date is appropriate because the MRI of 20 February 2014, three weeks earlier, showed intact talar dome cartilage, and he reported the new deep ankle pain on the day of surgery, with an acute lesion and marrow oedema confirmed on MRI on 05 May 2014. It falls within continuous full-time service.
Both causative factors are tied to the moment of onset rather than to a window before it. The significant physical force through the joint (invasive distraction and forced stress testing) and the intra-articular surgery (debridement and ligament reconstruction) were both applied on 14 Mar 2014, the date the cartilage tear occurred and the sudden pain began. No earlier time window needs to be filled.
For the worsening factor, the period after onset runs from 14 Mar 2014 to the documented worsening on 12 Mar 2018. The recommended debridement and microfracture could not be performed during his deployment from 10 Oct 2017 to 02 Jun 2018, and the lesion enlarged from 9 by 7 mm to 14 by 10 mm, with an unstable fragment and subchondral cyst, within that period.
1. What is the formal diagnosis of the condition claimed above?
The formal diagnosis is an osteochondral lesion of the lateral talar dome of the left ankle (ICD-10-AM M93.27), an acute traumatic tear of the articular cartilage and subchondral bone, decided under the Statements of Principles concerning acute articular cartilage tear, Balance of Probabilities No. 22 of 2019 and Reasonable Hypothesis No. 21 of 2019.
An osteochondral lesion of the talus is damage to the articular (hyaline) cartilage of the talar dome and the bone beneath it. Acute lesions follow a discrete event that shears or compresses the cartilage, such as a severe ankle injury or direct mechanical trauma, and cause sudden deep ankle pain, swelling, catching and locking. Cartilage has a poor capacity to heal; without treatment a flap or fragment can become unstable, fluid can enter the subchondral bone and form a cyst, and the joint degenerates.
The diagnosis followed the chronic ankle instability that developed after the veteran's 2010 inversion injury on warlike service. The tear occurred during corrective surgery on 14 March 2014, was confirmed on MRI on 05 May 2014, and enlarged and became unstable by March 2018 when treatment could not be obtained.
2. For each diagnosis identified, please also provide the following dates:
When did the veteran first experience symptoms attributable to this condition?
14 March 2014.
When did the veteran first present to a health / medical provider for this condition?
14 March 2014.
When was the condition confirmed / formally diagnosed?
05 May 2014.
When did the veteran first present to you (or your practice) for this condition?
09 September 2025.
3. How was this diagnosis confirmed? i.e. what were the key symptoms and signs, investigation results, specialist opinions?
The diagnosis was confirmed on MRI on 05 May 2014, which showed an acute 9 by 7 mm osteochondral lesion of the lateral talar dome with a partially detached cartilage flap and surrounding marrow oedema, in an area shown to be intact on MRI three weeks before the surgery. The sudden onset of pain and tenderness and the acute marrow oedema meet the Statement of Principles definition of an acute articular cartilage tear, and exclude a chronic or degenerative tear.
An orthopaedic surgeon confirmed the diagnosis. MRI on 12 March 2018, CT on 02 July 2018 and the findings at arthroscopy on 16 July 2018 confirmed enlargement, fragment instability and cyst formation.
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.
Legislation: the clinical onset of this condition was on 14 March 2014, after 1 July 2004, during continuous full-time service. This is a Military Rehabilitation and Compensation Act 2004 (MRCA) claim and the Statements of Principles apply. The Reasonable Hypothesis instrument applies to the veteran's warlike service in Afghanistan in 2010, where the ankle injury that led to the surgery occurred, and in the Middle East in 2017 to 2018, where the condition worsened. The Balance of Probabilities instrument applies to his peacetime service, including the parachuting sprains and the surgery itself. Factor 9(3) applies only to material contribution to, or aggravation of, the condition.
Each factor must be related to the person's relevant 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.
Balance of Probabilities — Statement of Principles concerning Acute Articular Cartilage Tear, No. 22 of 2019
Causative factors
Factor 9(1): having a significant physical force applied to or through the affected joint at the time of the clinical onset of acute articular cartilage tear; — MET
- At the arthroscopy of the left ankle on 14 March 2014, performed for chronic anterolateral impingement and lateral ligament instability, the ankle was held in an invasive distractor with pins in the distal tibia and talar neck and distracted under tension, and the surgeon applied repeated forced inversion and anterior drawer stress to confirm instability. The operation note records that the joint was 'tight' and required increased distraction force. This significant physical force was applied through the left ankle joint on the day of onset, and from recovery that afternoon the veteran had deep lateral ankle pain and tenderness out of proportion to the procedure. The surgery treated instability caused by an ankle injury in his peacetime parachute training as well as on operations.
Factor 9(2): having intra-articular surgery of the affected joint at the time of the clinical onset of acute articular cartilage tear; — MET
- The arthroscopic debridement of anterolateral impingement and the modified Broström lateral ligament reconstruction with two suture anchors, performed on 14 March 2014, was intra-articular surgery of the left ankle. During instrument passage through the tight anterolateral portal the shaver contacted the lateral talar dome, and MRI on 05 May 2014 showed an acute 9 by 7 mm osteochondral flap at that site, with marrow oedema, that was absent on the pre-operative MRI of 20 February 2014. The cartilage tear occurred at the time of the surgery, which was the clinical onset.
Worsening factors
Factor 9(3): inability to obtain appropriate clinical management for acute articular cartilage tear; — MET
- After the diagnosis the orthopaedic surgeon recommended arthroscopic debridement and microfracture of the lesion with six weeks of non-weight bearing. From 10 October 2017 to 02 June 2018 the veteran was deployed and the procedure could not be performed, and he continued to carry loads of up to 40 kg on patrols over rough ground. MRI on 12 March 2018 showed enlargement of the lesion to 14 by 10 mm with an unstable fragment and a subchondral cyst. Under Brew v Repatriation Commission (1999) this is an inability to obtain appropriate clinical management, and it materially contributed to and aggravated the condition.
Reasonable Hypothesis — Statement of Principles concerning Acute Articular Cartilage Tear, No. 21 of 2019
Causative factors
Factor 9(1): having a significant physical force applied to or through the affected joint at the time of the clinical onset of acute articular cartilage tear; — MET
- The significant distraction and stress forces applied through the left ankle during the arthroscopy on 14 March 2014 were applied in treating chronic lateral ligament instability that resulted from an inversion injury sustained on foot patrol during warlike service in Afghanistan on 17 July 2010. The forces were applied on the day of onset, and the veteran had immediate deep lateral ankle pain and tenderness afterwards.
Factor 9(2): having intra-articular surgery of the affected joint at the time of the clinical onset of acute articular cartilage tear; — MET
- The intra-articular surgery of 14 March 2014, arthroscopic debridement with a lateral ligament reconstruction, was required because of the ankle instability that followed the inversion injury on warlike service in Afghanistan on 17 July 2010. The acute osteochondral flap of the lateral talar dome was caused during that surgery, at onset, and was confirmed on MRI on 05 May 2014.
Worsening factors
Factor 9(3): inability to obtain appropriate clinical management for acute articular cartilage tear; — MET
- From 10 October 2017 to 02 June 2018, on warlike service in the Middle East, the veteran could not obtain the recommended debridement and microfracture, and the lesion enlarged from 9 by 7 mm to 14 by 10 mm with an unstable fragment and subchondral cyst on MRI on 12 March 2018.
The % contribution of the causes is 100% and significant.
Sequelae
The osteochondral lesion is a sequela of the veteran's accepted left ankle lateral ligament instability, which arose from the inversion injury on warlike service in Afghanistan in 2010 and repeated parachuting sprains. Its own sequelae are post-traumatic osteoarthritis of the left ankle and altered gait with secondary knee and lower back pain.
Unintended Consequence
Met. The cartilage tear was caused during arthroscopic surgery and lateral ligament reconstruction performed and paid for by the Commonwealth on 14 March 2014 to treat a service-related injury. An injury sustained in the course of treatment provided by the Commonwealth is an unintended consequence of that treatment (section 6A of the DRCA and the equivalent provisions of the MRCA).
Inability to Attain Appropriate Medical Management
MET. Debridement and microfracture were recommended after the diagnosis in May 2014 and scheduled, but from 10 October 2017 to 02 June 2018 the veteran was deployed on warlike service and the procedure could not be performed. He continued patrolling with 40 kg loads, and MRI on 12 March 2018 showed the lesion enlarged with an unstable fragment and a subchondral cyst. Applying the objective and subjective tests in Brew v Repatriation Commission (Full Federal Court, 10 September 1999, Merkel J), treatment that is recommended but cannot be delivered because of the circumstances of service is an inability to obtain appropriate clinical management.
5. Please provide a Health Summary and a medication / prescribing history.
See attached report.
References
- 17 Jul 2010, Regimental aid post record, Medical Officer, Afghanistan
- 22 Aug 2012, Outpatient health record, Medical Officer, Base medical centre
- 20 Feb 2014, MRI left ankle, Radiologist
- 14 Mar 2014, Operation report, Orthopaedic surgeon
- 05 May 2014, MRI left ankle and orthopaedic consultation, Orthopaedic surgeon
- 12 Mar 2018, MRI left ankle, Coalition role 2 facility, Middle East
- 02 Jul 2018, CT left ankle, Radiologist
- 16 Jul 2018, Operation report, Orthopaedic surgeon
- Statement of Principles concerning Acute Articular Cartilage Tear (Balance of Probabilities) No. 22 of 2019, Repatriation Medical Authority
- Statement of Principles concerning Acute Articular Cartilage Tear (Reasonable Hypothesis) No. 21 of 2019, Repatriation Medical Authority
