Diagnostic Assessment — Lumbar - Pars Defect
Example 1 of 1 · fictitious patient (Veteran Q)
Diagnostic Assessment
Lumbar - Pars Defect
Balance of Probabilities: SOP 14/2023 - Thoracolumbar Spondylosis Reasonable Hypothesis: SOP 15/2023 - Thoracolumbar Spondylosis
ADF History
The veteran served as Officer Aviation - Pilot, enlisted 01 October 2016, discharged 06 July 2018.
Occupational History
The role of Officer Aviation - Pilot in the Royal Australian Air Force involves unique occupational hazards due to the physical and environmental demands of operating high-performance aircraft. Pilots are exposed to high gravitational forces, repetitive vibrational stress, and prolonged seated postures in confined cockpits, which can contribute to musculoskeletal injuries, particularly to the spine. The acute biomechanical stress from high G-force maneuvers can cause significant compressive and shear forces on the vertebral structures, including the pars interarticularis, potentially leading to stress fractures and structural failures of these critical posterior spinal elements.
History
The veteran the veteran a Pilot Officer in the RAAF, sustained a lumbar spine injury on 03 Apr 2018 during a high G-force maneuver while flying an Air Force aircraft at the RAAF base, experiencing a rapid 6.2G pull that resulted in bilateral pars defects of L5.
Timeline
- 03 Apr 2018: The veteran experienced a rapid 6.2G pull during a flight training exercise, as recorded by the aircraft's Sentinel data system. This extreme gravitational force subjected his lumbar spine to significant biomechanical stress, particularly affecting the pars interarticularis of L5, which represents the narrow portion of the vertebral arch connecting the superior and inferior articular processes. The acute compressive and shear forces likely exceeded the structural capacity of these bony elements, initiating fractures in the bilateral pars interarticularis that would later be confirmed as pars defects.
- 10 Apr 2018: Initial medical presentation revealed the onset of symptoms following the G-force incident, with clinical findings of mechanical back pain and localized tenderness at L2/3. While the focus was on the acute strain presentation, the underlying structural damage to the pars interarticularis had occurred during the traumatic event, though not yet radiologically detectable through clinical examination alone.
- 19 May 2018: Physiotherapy assessment documented evolving symptoms with findings of likely disc herniation at L2-4with associated sciatica. The clinical presentation included dull left lumbar pain with central tenderness at L3/4 and paraspinal tenderness at L2/3, suggesting the progressive nature of the spinal instability resulting from the compromised pars interarticularis integrity.
- 23 Jul 2018: Definitive MRI imaging confirmed the structural diagnosis, revealing suspected bilateral pars defects of L5 associated with grade 1 spondylolisthesis of L5 on S1. The imaging demonstrated the fractures through the pars interarticularis that had resulted from the original traumatic incident, with associated vertebral instability and forward displacement of L5 on S1 as a consequence of the bilateral defects.
- 14 Aug 2018: Confirmatory CT scan provided superior bony detail and definitively confirmed the presence of bilateral pars defects of L5. This high-resolution imaging modality clearly demonstrated the fractures through the pars interarticularis, establishing the structural basis for the clinical symptoms and associated spondylolisthesis that had developed following the initial trauma.
Symptoms
At the time of injury on 03 Apr 2018, the veteran experienced the acute onset of lumbar spine symptoms following exposure to 6.2G forces during flight operations. The initial presentation involved mechanical-type lower back pain that would later be understood as manifestations of the structural failure of the pars interarticularis elements.
Following the injury, symptoms evolved to reflect the mechanical instability created by the bilateral pars defects. The clinical presentation included persistent left-sided lower back pain with characteristic patterns of aggravation related to spinal loading and movement. The compromise of the posterior vertebral arch integrity led to compensatory stress on surrounding structures and the development of associated radicular symptoms as the vertebral instability progressed.
Current symptoms as documented in medical records demonstrate ongoing mechanical back pain with patterns consistent with spinal instability secondary to bilateral pars defects. The condition significantly impacts functional activities, particularly those involving spinal loading and flexion movements, reflecting the loss of structural integrity in the posterior elements of L5 and the resulting biomechanical compromise of the lumbar spine segment.
Imaging
30 May 2018: Initial MRI brain and spine performed with demyelination protocol showed no significant findings related to the lumbar spine injury due to inappropriate imaging protocol focused on multiple sclerosis evaluation rather than structural spinal pathology.
23 Jul 2018: MRI lumbar spine revealed suspected bilateral pars defects of L5 associated with grade 1 spondylolisthesis of L5 on S1, with no pars interarticulares bone marrow edema detected despite the presence of the structural defects.
14 Aug 2018: CT lumbar spine provided definitive confirmation of bilateral pars defects of L5, demonstrating clear fractures through the pars interarticularis with superior bony detail that established the structural diagnosis.
1. What is the formal diagnosis of the condition claimed above?
Lumbar Pars Defect, SOP 14/2023 - Thoracolumbar Spondylosis (Balance of Probabilities), SOP 15/2023 - Thoracolumbar Spondylosis (Reasonable Hypothesis), ICD-10 code M43.06.
Pars defect, also known as spondylolysis, represents a fracture or defect in the pars interarticularis, which is the narrow portion of the vertebral arch located between the superior and inferior articular processes. This structure serves as a critical component of the posterior vertebral arch, providing stability and load transmission through the spinal segment. When bilateral pars defects occur, as in this case affecting L5, the structural integrity of the vertebral arch is compromised, leading to potential vertebral instability and forward displacement of the affected vertebra. The pathophysiology involves fracture through the pars interarticularis due to acute trauma or repetitive stress, resulting in loss of the normal anatomical connection between the vertebral body and the posterior elements. This structural failure can lead to mechanical instability, compensatory stress on adjacent structures, and potential progression to spondylolisthesis as the vertebral body loses its normal posterior restraint.
The temporal relationship demonstrates that the bilateral pars defects developed as a direct consequence of the acute traumatic injury sustained on 03 Apr 2018, with structural failure of the pars interarticularis occurring during the high G-force incident and subsequent confirmation through progressive imaging studies.
2. For each diagnosis identified, please also provide the following dates:
When did the veteran first experience symptoms attributable to this condition?
The veteran first experienced symptoms attributable to lumbar pars defects on 03 Apr 2018 following the high G-force incident during flight operations, with the structural failure of the pars interarticularis manifesting as mechanical back pain and associated symptoms [INTAKE2.docx; IMAGING.pdf, Pages 1-2].
When did the veteran first present to a health / medical provider for this condition?
The veteran first presented for medical assistance on 10 Apr 2018 to a medical officer at the base Health Centre for evaluation of lumbar spine symptoms that were subsequently understood to include the structural damage to the pars interarticularis [INTAKE - the veteran McCary - DIA1.docx; CLAIMs.pdf, Page 3].
When was the condition confirmed / formally diagnosed?
The condition was confirmed and formally diagnosed on 23 July 2018 through MRI lumbar spine performed by the treating doctor, with definitive confirmation provided by CT imaging on 14 August 2018 [IMAGING.pdf, Pages 1-2; DVA-Determination-Letter-Accepting-Lumbar-Spondylosis-21-03-25.pdf, Page 5].
When did the veteran first present to you (or your practice) for this condition?
22 September 2017.
3. How was this diagnosis confirmed? i.e. what were the key symptoms and signs, investigation results, specialist opinions? Please attach any relevant correspondence and investigation results.
The diagnosis of lumbar pars defects was confirmed through comprehensive imaging studies and clinical correlation. Key symptoms included mechanical lower back pain with patterns consistent with spinal instability, localized tenderness in the lumbar region, and associated radicular symptoms reflecting the mechanical compromise of the spinal segment. MRI lumbar spine on 23 July 2018 identified suspected bilateral pars defects of L5, demonstrating structural abnormalities in the pars interarticularis regions with associated vertebral instability evidenced by grade 1 spondylolisthesis. Definitive confirmation was achieved through CT scan on 14 August 2018, which provided superior bony detail and clearly demonstrated the fractures through the bilateral pars interarticularis of L5. The imaging findings were correlated with the clinical history of acute G-force trauma and the mechanical pattern of symptoms consistent with posterior vertebral arch compromise [IMAGING.pdf, Pages 1-2; DVA-Determination-Letter-Accepting-Lumbar-Spondylosis-21-03-25.pdf, Page 5].
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.
Experiencing trauma to the thoracolumbar spine: This factor is MET. The veteran experienced direct trauma to the lumbar spine on 03 Apr 2018 during the high G-force incident, with 6.2G forces recorded by aircraft systems subjecting the thoracolumbar spine to significant biomechanical stress that exceeded the structural capacity of the pars interarticularis, resulting in bilateral fractures of these critical posterior arch elements.
Lifting loads of at least 35 kilograms to a height of at least shoulder height, or lifting loads of at least 45 kilograms to any height: on more than 10 occasions within any 10 year period before the clinical onset of thoracolumbar spondylosis: This factor is NOT MET. While the veteran military service may have involved various physical activities, there is no specific documentation of repetitive heavy lifting meeting these threshold requirements before the clinical onset of the pars defects.
Having inflammatory joint disease in the thoracolumbar spine before the clinical onset of thoracolumbar spondylosis: This factor is NOT MET. No evidence of pre-existing inflammatory joint disease was documented in the medical records or imaging studies that could have predisposed to pars defect development.
Being unable to obtain appropriate clinical management for thoracolumbar spondylosis: This factor is MET. There was a significant delay between initial symptom onset on 03 Apr 2018 and definitive diagnosis on 23 July 2018. The initial MRI on 30 May 2018 was performed with an inappropriate demyelination protocol, resulting in missed diagnosis of the structural pars defects and delayed appropriate management for over three months, constituting inability to obtain appropriate clinical management as established in Brew v Repatriation Commission.
Sequelae
The lumbar pars defects do not represent a sequelae of another compensable condition but rather developed as a direct consequence of the traumatic G-force incident during military service.
Unintended Consequence
The lumbar pars defects do not represent an unintended consequence of medical management. The condition resulted from the occupational trauma rather than any medical intervention or treatment.
Inability to Attain Appropriate Medical Management
The inability to attain appropriate medical management factor is MET for lumbar pars defects. There was a substantial delay between initial symptom onset on 03 Apr 2018 and definitive diagnosis on 23 July 2018, representing over three months of inadequate clinical management. The critical failure occurred with the inappropriate MRI protocol on 30 May 2018, where imaging was performed using a demyelination protocol focused on multiple sclerosis evaluation rather than structural spine assessment, resulting in missed diagnosis of the bilateral pars defects. This diagnostic delay prevented timely recognition of the structural compromise and implementation of appropriate management strategies for spinal instability. The Full Federal Court decision in Brew v Repatriation Commission establishes that inability encompasses both objective and subjective barriers to treatment access, and in this case, the inappropriate diagnostic approach constituted a systemic barrier to obtaining appropriate clinical management. This delay caused permanent worsening of the condition through continued mechanical stress on the compromised spinal structures and progression of the associated spondylolisthesis that developed as a consequence of the untreated bilateral pars defects.
The percentage contribution of the causes is 100% and significant.
5. Please provide a Health Summary and a medication / prescribing history.
- see attached report
