Left Knee - Medial Meniscal Tear — DVA claim example

Diagnostic Assessment — Left Knee - Medial Meniscal Tear

Example 1 of 1 · fictitious patient (Veteran X)

Diagnostic Assessment

Left Knee - Medial Meniscal Tear

BOP Code: 8 of 2019 (Internal Derangement of the Knee)
RH Code: 7 of 2019 (Internal Derangement of the Knee)

ADF History

Veteran X, date of birth 11 October 1985, Australian Army, Infantry Soldier (Rifleman, later Section Second-in-Command), enlisted 26 July 2004, medically discharged 15 April 2016. Operational service: Afghanistan, 10 April 2009 to 28 October 2009 (warlike); Afghanistan, 14 February 2012 to 19 July 2012 (warlike, ended by aeromedical evacuation).

Occupational History

As an infantry soldier the veteran carried loads of 35 to 45 kilograms on foot over broken ground, jumped from walls, vehicles and helicopters, cleared compounds, crossed irrigation ditches and moved at a run under fire. Training included obstacle courses, fast-roping, loaded pack marches and field exercises in rough terrain, often at night under night-vision goggles.

Twisting, pivoting and landing injuries of the knee are among the most common injuries in infantry soldiers, particularly under load, and repeated injury to an already damaged knee is frequent because soldiers are expected to keep working through pain on exercise and on operations.

History

Veteran X, an infantry soldier in the Australian Army, sustained a medial collateral ligament sprain and an acute tear of the left medial meniscus on a pre-deployment exercise in February 2009, re-injured the knee on warlike service in Afghanistan in June 2009, and developed a chronic internal derangement of the left knee from 01 September 2009. It worsened with a displaced bucket-handle tear on 18 July 2012 after further injuries in training and in Afghanistan.

Timeline

• 14 Jan 2009 — Pre-deployment periodic health examination at the battalion's regimental aid post. No history of knee injury. Full range of movement of both knees, stable ligaments, no effusion and negative McMurray tests. Fit for deployment to Afghanistan. "knees normal, fit to deploy"
• 17 Feb 2009 — During a mission rehearsal exercise in northern Australia the veteran caught his left foot in a washout while running under a 38 kg load, twisting the knee. He felt a pop and the knee swelled within two hours. The regimental medical officer found medial joint line tenderness, a painful McMurray test and valgus laxity with a firm end point. He was placed on restricted duties with a hinged brace. MRI on 03 March 2009 showed a grade II medial collateral ligament sprain and an acute 11 mm vertical longitudinal tear of the posterior horn of the medial meniscus. "MCL grade II, acute meniscal tear"
• 22 Jun 2009 — On warlike service in Afghanistan the veteran jumped 1.8 metres from a compound wall under threat of fire carrying 42 kg, landing on the left leg with the knee twisting. The patrol medic splinted the knee. At the role 2 facility the medical officer found an effusion, valgus laxity and a positive Lachman test with a firm end point. No MRI was available in theatre. He was given anti-inflammatories and returned to patrolling after ten days. "twisting injury, effusion, Lachman positive"
• 07 Sep 2009 — At the role 2 facility the veteran reported that since 01 September 2009 the left knee had locked several times a day, given way on uneven ground and swelled after every patrol. Examination showed a moderate effusion, medial joint line tenderness, a block to full extension of 10 degrees and a positive McMurray test. The medical officer diagnosed a symptomatic medial meniscal tear with ligamentous laxity and recommended arthroscopy on return to Australia. He completed the deployment. "locking, giving way, extension block"
• 19 Nov 2009 — MRI in Australia after return from deployment showed extension of the posterior horn tear of the medial meniscus to 24 mm with a displaced flap, a partial tear of the anterior cruciate ligament and a healing medial collateral ligament sprain. An orthopaedic surgeon diagnosed internal derangement of the left knee and placed him on the waiting list for arthroscopy. "tear 24 mm, ACL partial tear"
• 08 Feb 2010 — Arthroscopic partial medial meniscectomy of the unstable flap was performed. The remaining longitudinal component of the tear was judged stable and left in situ. The anterior cruciate ligament was partially torn but functionally competent. After rehabilitation he returned to full duties in June 2010 but continued to have intermittent medial pain and swelling after long marches. "partial meniscectomy, residual tear"
• 05 Nov 2011 — During a peacetime mission rehearsal exercise the veteran fell while dismounting from a protected mobility vehicle under load and twisted the left knee again, with immediate pain and swelling. MRI on 21 November 2011 showed a recurrent grade II medial collateral ligament sprain and a new acute radial tear of the medial meniscus with bone bruising of the medial tibial plateau. Repeat arthroscopy was recommended but deferred so that he could deploy in February 2012. "re-sprain MCL, new radial tear"
• 18 Jul 2012 — On warlike service in Afghanistan, 16 days after falling into an irrigation ditch during a night patrol, the veteran's left knee locked in 25 degrees of flexion and could not be straightened. He was aeromedically evacuated. MRI on 20 July 2012 showed a displaced bucket-handle tear of the medial meniscus in the intercondylar notch and a fresh medial collateral ligament sprain. Arthroscopy on 24 July 2012 reduced and repaired the bucket-handle fragment. "locked knee, bucket-handle tear"
• 15 Apr 2016 — Separation medical examination. Persistent medial knee pain, recurrent effusions, giving way on stairs and uneven ground and inability to run or carry loads. Quadriceps wasting of 2.5 cm on the left. He was medically discharged as unable to meet infantry employment standards because of the left knee. "recurrent effusions, quadriceps wasting"

Symptoms

At onset the veteran had recurrent locking of the left knee several times a day, giving way on uneven ground, swelling after every patrol, medial joint line pain and inability to fully straighten the knee. After the 2010 partial meniscectomy the locking settled but medial pain and swelling after marches persisted, and after the 2012 worsening the knee locked fully and required surgical repair.

He now reports daily medial knee pain, swelling after walking more than two kilometres, giving way on stairs and slopes, clicking, inability to run, kneel or squat, and difficulty with lifting, carrying and sport.

Imaging

• 03 Mar 2009 — MRI left knee: "Grade II sprain of the medial collateral ligament. Acute 11 mm vertical longitudinal tear of the posterior horn of the medial meniscus with parameniscal oedema. Cruciate ligaments intact. No degenerative meniscal signal or chondral loss."
• 19 Nov 2009 — MRI left knee: "Extension of the posterior horn tear of the medial meniscus to 24 mm with a displaced flap. Partial-thickness tear of the anterior cruciate ligament. Healing medial collateral ligament sprain. Moderate effusion."
• 21 Nov 2011 — MRI left knee: "Post-operative partial meniscectomy. New acute radial tear at the junction of the body and posterior horn of the medial meniscus with bone bruising of the medial tibial plateau. Recurrent grade II medial collateral ligament sprain."
• 20 Jul 2012 — MRI left knee: "Displaced bucket-handle tear of the medial meniscus with the fragment in the intercondylar notch (double posterior cruciate ligament sign). Fresh grade II medial collateral ligament sprain. Large effusion."
• 02 Mar 2016 — X-ray left knee, weight-bearing: "Mild narrowing of the medial compartment joint space. No fracture or loose body."

Onset Date

The most likely date of onset of this condition is 01 Sep 2009.

At that date the veteran was an infantry soldier on warlike service in Afghanistan, conducting daily foot patrols carrying about 40 kg. From that date his left knee locked several times a day, gave way on uneven ground and swelled after every patrol, which are the ongoing and recurrent symptoms that characterise internal derangement of the knee as a chronic disorder rather than an acute injury.

This date is appropriate because the knee was normal at the periodic health examination on 14 January 2009, and the acute injuries of 17 February 2009 and 22 June 2009 were each followed by a period of recovery and return to duty. The first record of the established chronic pattern is the role 2 consultation on 07 September 2009, at which he dated the persistent locking and giving way to 01 September 2009. It falls within continuous full-time service.

For the causative factors, the one year before onset runs from 01 Sep 2008 to 01 Sep 2009. That window contains the peacetime exercise injury of 17 Feb 2009 (medial collateral ligament sprain and acute medial meniscal tear) and the warlike service injury of 22 Jun 2009 in Afghanistan (anterior cruciate and medial collateral ligament sprain and acute extension of the meniscal tear).

For the worsening factors, the documented clinical worsening is the locked bucket-handle tear on 18 Jul 2012. The one year before the worsening runs from 18 Jul 2011 to 18 Jul 2012 and contains the peacetime exercise injury of 05 Nov 2011 (recurrent medial collateral ligament sprain and new acute radial tear) and the warlike service injury of 02 Jul 2012 in Afghanistan (fresh medial collateral ligament sprain and acute extension to a bucket-handle tear).

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

The formal diagnosis is Left Knee - Medial Meniscal Tear, a chronic internal derangement of the left knee due to a traumatic tear of the posterior horn of the medial meniscus with associated collateral and cruciate ligament sprain (ICD-10-AM M23.22), under the Statements of Principles concerning internal derangement of the knee, Balance of Probabilities No. 8 of 2019 and Reasonable Hypothesis No. 7 of 2019.

Internal derangement of the knee is a chronic disorder of the knee due to a torn meniscus or a torn or stretched collateral, cruciate or capsular ligament. The medial meniscus is a C-shaped fibrocartilage cushion between the femur and tibia, and a traumatic tear, usually from a twisting injury on a bent, weight-bearing knee, causes medial pain, swelling, catching, locking and giving way. Unstable tears can extend into a bucket-handle tear that displaces into the joint and locks the knee. Persistent meniscal deficiency increases the load on the articular cartilage and leads to early osteoarthritis.

The condition followed traumatic injuries in February and June 2009, was established as a chronic derangement from 01 September 2009, was confirmed on MRI on 19 November 2009 and worsened with a displaced bucket-handle tear on 18 July 2012.

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

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

01 September 2009.

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

07 September 2009.

When was the condition confirmed / formally diagnosed?

19 November 2009.

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

09 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 19 November 2009, which showed a 24 mm vertical longitudinal tear of the posterior horn of the left medial meniscus with a displaced flap, a partial anterior cruciate ligament tear and a healing medial collateral ligament sprain, and by arthroscopy on 08 February 2010, which confirmed the unstable traumatic tear. The tear was traumatic, not degenerative: it followed discrete twisting injuries in a young soldier with a previously normal knee, and the MRI of 03 March 2009 showed no degenerative meniscal signal.

The clinical picture met the Statement of Principles definition of internal derangement of the knee as a chronic disorder due to a torn meniscus and stretched ligaments, with ongoing and recurrent pain, swelling, instability, locking and altered mobility. The exclusions do not apply: there is no patellar disorder, discoid meniscus, osteochondritis dissecans, meniscal cyst, degenerative tear, osteoarthritis or loose body. The worsening was confirmed by MRI on 20 July 2012 and arthroscopy on 24 July 2012.

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 01 September 2009, 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 Balance of Probabilities instrument applies to peacetime service, including the mission rehearsal exercises of February 2009 and November 2011. The Reasonable Hypothesis instrument applies to the veteran's warlike service in Afghanistan in 2009, where the onset occurred, and in 2012, where the condition worsened.

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 Internal Derangement of the Knee, No. 8 of 2019

Causative factors

Factor 9(1): having a sprain involving a ligament of the affected knee within the one year before the clinical onset of internal derangement of the knee; — MET

- On 17 February 2009, during a pre-deployment mission rehearsal exercise in northern Australia (peacetime service), the veteran's left foot caught in a washout while he was moving at a run under a 38 kg load and his knee was forced into valgus and external rotation. He felt a pop and the knee swelled within two hours. The regimental medical officer found medial joint line and medial collateral ligament tenderness with laxity on valgus stress at 30 degrees but a firm end point, and MRI on 03 March 2009 confirmed a grade II sprain of the medial collateral ligament. This sprain occurred 6 months and 15 days before the clinical onset of internal derangement on 01 September 2009, within the one year before onset.

Factor 9(2): having an acute meniscal tear of the affected knee within the one year before the clinical onset of internal derangement of the knee; — MET

- The same exercise injury of 17 February 2009 produced an acute vertical longitudinal tear of the posterior horn of the left medial meniscus, 11 mm long, shown on MRI on 03 March 2009 with surrounding oedema and no degenerative signal elsewhere in the meniscus. The tear followed a single, discrete twisting injury in a 23-year-old with a previously normal knee and is an acute traumatic tear, not a degenerative one. It occurred within the one year before the clinical onset on 01 September 2009.

Worsening factors

Factor 9(3): having a sprain involving a ligament of the affected knee within the one year before the clinical worsening of internal derangement of the knee; — MET

- On 05 November 2011, during a peacetime mission rehearsal exercise, the veteran fell while dismounting from a protected mobility vehicle under load and twisted the left knee again. He had immediate medial pain and swelling, and MRI on 21 November 2011 showed a recurrent grade II sprain of the medial collateral ligament. This sprain occurred 8 months and 13 days before the clinical worsening on 18 July 2012, within the one year before the worsening.

Factor 9(4): having an acute meniscal tear of the affected knee within the one year before the clinical worsening of internal derangement of the knee; — MET

- The MRI of 21 November 2011 also showed a new acute radial tear at the junction of the body and posterior horn of the left medial meniscus, separate from the residual 2009 tear, with adjacent bone bruising of the medial tibial plateau confirming its acute traumatic origin. This tear occurred on 05 November 2011, within the one year before the clinical worsening on 18 July 2012, and the displaced bucket-handle fragment found at arthroscopy on 24 July 2012 propagated from it.

Factor 9(5): inability to obtain appropriate clinical management for internal derangement of the knee. — MET

- After the clinical onset on 01 September 2009 the veteran was on warlike service in Afghanistan, where no MRI or orthopaedic surgeon was available at his forward operating base. He continued foot patrols carrying 40 kg with a knee that locked and gave way, and the arthroscopy recommended in September 2009 was not performed until 08 February 2010. After the November 2011 injury his referral for repeat arthroscopy was deferred so that he could deploy in February 2012, and the derangement went untreated until the knee locked on 18 July 2012. Each delay arose from service requirements, not the veteran's choice.

Reasonable Hypothesis — Statement of Principles concerning Internal Derangement of the Knee, No. 7 of 2019

Causative factors

Factor 9(1): having a sprain involving a ligament of the affected knee within the one year before the clinical onset of internal derangement of the knee; — MET

- On 22 June 2009, during warlike service in Afghanistan, the veteran jumped 1.8 metres from a compound wall while carrying 42 kg of equipment on a foot patrol under threat of small arms fire, landing awkwardly on the left leg with the knee twisting inwards. He had immediate pain and swelling. The patrol medic and the role 2 medical officer recorded medial collateral ligament tenderness with increased valgus laxity and a positive Lachman test with a firm end point, and MRI in Australia on 19 November 2009 showed a partial tear of the anterior cruciate ligament with a healing medial collateral ligament sprain. This sprain occurred 2 months and 10 days before the clinical onset on 01 September 2009.

Factor 9(2): having an acute meniscal tear of the affected knee within the one year before the clinical onset of internal derangement of the knee; — MET

- The fall of 22 June 2009 on warlike service in Afghanistan extended the posterior horn tear of the left medial meniscus: MRI on 19 November 2009 showed the vertical longitudinal tear lengthened from 11 mm to 24 mm, with a new displaced flap and fresh parameniscal oedema, an acute traumatic tear. This occurred within the one year before the clinical onset on 01 September 2009.

Worsening factors

Factor 9(3): having a sprain involving a ligament of the affected knee within the one year before the clinical worsening of internal derangement of the knee; — MET

- On 02 July 2012, during warlike service in Afghanistan, the veteran fell into an irrigation ditch while patrolling at night under night-vision goggles, carrying 40 kg. His left knee was forced into valgus and rotation, and the role 2 medical officer recorded medial collateral ligament tenderness and laxity. MRI on 20 July 2012 confirmed a fresh grade II medial collateral ligament sprain with oedema around the anterior cruciate ligament. The sprain occurred 16 days before the clinical worsening on 18 July 2012.

Factor 9(4): having an acute meniscal tear of the affected knee within the one year before the clinical worsening of internal derangement of the knee; — MET

- The fall of 02 July 2012 on warlike service in Afghanistan caused an acute extension of the radial tear of the medial meniscus into a bucket-handle tear, shown on MRI on 20 July 2012 as a displaced fragment in the intercondylar notch with fresh oedema, and confirmed at arthroscopy on 24 July 2012. The acute tear occurred within the one year before the clinical worsening on 18 July 2012.

Factor 9(5): inability to obtain appropriate clinical management for internal derangement of the knee. — MET

- On warlike service in Afghanistan from September to October 2009 and from February to July 2012, the veteran had no access to MRI or orthopaedic review at his forward operating base and continued patrolling under heavy load with a knee that locked and gave way. Arthroscopy recommended in September 2009 was delayed until February 2010, and repeat arthroscopy recommended in November 2011 was deferred so that he could deploy. The internal derangement went untreated until it locked on 18 July 2012.

The % contribution of the causes is 100% and significant.

Sequelae

The internal derangement has resulted in quadriceps wasting, early medial compartment narrowing consistent with developing osteoarthritis of the left knee after partial meniscectomy, and an altered gait that has caused right knee and lower back pain. These are sequelae of the accepted condition and can be claimed in their own right when diagnosed.

Unintended Consequence

Met. The partial medial meniscectomy of 08 February 2010, provided and paid for by the Commonwealth, removed part of the meniscus and increased the load on the medial compartment, contributing to the early medial joint space narrowing recorded in 2016. That narrowing is an unintended consequence of treatment of the accepted condition (section 6A of the DRCA and the equivalent provisions of the MRCA).

Inability to Attain Appropriate Medical Management

MET. On warlike service in Afghanistan in 2009 the veteran had a knee that locked and gave way but no access to MRI or an orthopaedic surgeon, and he continued foot patrols with 40 kg loads for almost two months after onset. The arthroscopy recommended in September 2009 was delayed until February 2010, and the repeat arthroscopy recommended after the November 2011 injury was deferred so that he could deploy in February 2012, where the knee locked on 18 July 2012. Applying the objective and subjective tests in Brew v Repatriation Commission (Full Federal Court, 10 September 1999, Merkel J), treatment withheld or delayed because of operational and service requirements amounts to an inability to obtain appropriate clinical management.

5. Please provide a Health Summary and a medication / prescribing history.

See attached report.

References

1. 14 Jan 2009, Periodic health examination, Regimental Medical Officer
2. 17 Feb 2009, Exercise injury report and consultation, Regimental Medical Officer
3. 03 Mar 2009, MRI left knee, Radiologist
4. 22 Jun 2009, Patrol casualty record and role 2 consultation, Medical Officer, Afghanistan
5. 07 Sep 2009, Role 2 consultation, Medical Officer, Afghanistan
6. 19 Nov 2009, MRI left knee and orthopaedic consultation, Orthopaedic surgeon
7. 08 Feb 2010, Operation report, Orthopaedic surgeon
8. 21 Nov 2011, MRI left knee, Radiologist
9. 20 Jul 2012, MRI left knee, Radiologist
10. 24 Jul 2012, Operation report, Orthopaedic surgeon
11. 02 Mar 2016, X-ray left knee, Radiologist
12. 15 Apr 2016, Separation medical examination, Medical Officer
13. Statement of Principles concerning Internal Derangement of the Knee (Balance of Probabilities) No. 8 of 2019, Repatriation Medical Authority
14. Statement of Principles concerning Internal Derangement of the Knee (Reasonable Hypothesis) No. 7 of 2019, Repatriation Medical Authority