Diagnostic Assessment — Left Knee - Quadriceps Tendinosis With Partial Tear
Example 1 of 1 · fictitious patient (Veteran D)
Diagnostic Assessment
Left Knee - QUADRICEPS TENDINOSIS WITH PARTIAL TEAR
SOP: Sprain and Strain No. 28 of 2020 (BOP) Sprain and Strain No. 27 of 2020 (RH)
ADF History
The veteran, Airfield Defence Guard, enlisted on 29 July 1993, currently serving.
Occupational History
As an Airfield Defence Guard (ADG) in the Royal Australian Air Force, the veteran would have been exposed to a range of occupational hazards inherent to the role. This occupation is primarily focused on providing security and ground defence for RAAF assets, personnel, and installations, both within Australia and on deployment. The duties are physically demanding and can involve prolonged periods in various environmental conditions including manual handling of heavy equipment, weapons, ammunition, and field gear. This often involves lifting, carrying, and pack marching, frequently over uneven terrain and for extended durations. The role requires standing for extended periods, running, climbing, crawling, and adopting awkward positions during tactical exercises and operations. These activities place significant strain on the quadriceps muscle group and the associated tendons through repetitive forceful contractions during activities such as lifting, climbing, squatting, and running. The quadriceps tendon is particularly vulnerable to overuse injury and mechanical stress in military personnel due to these occupational demands.
History
The veteran an Airfield Defence Guard with the RAAF, developed significant tendinosis of the distal quadriceps insertion with a partial thickness tear, particularly affecting the rectus femoris tendon of the left knee. This condition was identified on MRI performed on 04 December 2018, approximately 2.5 months after he underwent ACL reconstruction surgery on the same knee. The tendinosis and partial tear likely developed as a result of altered biomechanics during rehabilitation and compensatory stress patterns following the knee surgery.
Timeline
- 14 Jul 2018. An MRI of the Left Knee was performed which identified an ACL rupture and other knee pathology. There is no specific mention of quadriceps tendon abnormalities in the available excerpts from this study, suggesting the tendinosis and partial tear developed subsequently.
- 26 Sep 2018. The veteran underwent ACL reconstruction surgery on his left knee. Following this procedure, he would have undergone rehabilitation including progressive strengthening of the quadriceps muscles, which can sometimes lead to excessive strain on the quadriceps tendon, particularly in the context of altered biomechanics.
- 04 Dec 2018. An MRI of Both Legs and Knees was performed, which revealed "Significant tendinosis of the distal quadriceps insertion with partial thickness tear at the distal quadriceps insertion...especially of the rectus femoris tendon." This finding indicates chronic degenerative changes in the quadriceps tendon (tendinosis) with superimposed acute/subacute partial tearing, primarily affecting the rectus femoris component of the quadriceps tendon.
Symptoms
At the time of diagnosis, the veteran would have experienced pain localized to the anterior aspect of the knee, particularly at or just above the superior pole of the patella where the quadriceps tendon inserts. This pain would typically be exacerbated by activities that contract the quadriceps muscle, such as ascending stairs, rising from a seated position, and especially eccentric loading during activities like descending stairs or controlled squatting.
Additional symptoms would likely have included weakness with knee extension, particularly against resistance, a sense of instability or giving way of the knee during activities, and possibly swelling in the suprapatellar region. There may have been tenderness to palpation directly over the quadriceps tendon insertion and pain with resisted knee extension.
Given that the condition was diagnosed in the context of post-ACL reconstruction rehabilitation, some of these symptoms might have initially been attributed to the normal post-surgical recovery process, potentially delaying recognition of the distinct tendon pathology.
Current symptoms would include persistent anterior knee pain, particularly with quadriceps contraction, residual weakness in knee extension strength, and functional limitations with activities requiring forceful quadriceps activation. The condition would interfere with military duties requiring running, jumping, heavy lifting, and tactical movements, and would require modification of physical training activities.
Imaging
04 December 2018: "Significant tendinosis of the distal quadriceps insertion with partial thickness tear at the distal quadriceps insertion...especially of the rectus femoris tendon." This MRI finding indicates chronic degenerative changes in the quadriceps tendon (tendinosis) with superimposed partial tearing, primarily affecting the rectus femoris component of the quadriceps tendon.
1. What is the formal diagnosis of the condition claimed above? Left Knee - Distal Quadriceps Tendinosis with Partial Tear (Rectus Femoris), ICD-10 code S76.112A, covered under the DVA SOP for Sprain and Strain No. 28 of 2020 (Balance of Probabilities).
Quadriceps tendinosis represents a degenerative condition of the quadriceps tendon characterized by mucoid degeneration, fibrinoid necrosis, and disorganization of collagen fibers, without significant inflammatory cells (distinguishing it from tendinitis). This chronic degenerative process weakens the tendon and predisposes it to partial or complete tearing with continued mechanical stress.
A partial thickness tear indicates disruption of some, but not all, of the tendon fibers, typically occurring in the setting of pre-existing tendinosis. The quadriceps tendon is a conjoined tendon formed by the four components of the quadriceps muscle group (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius), with the rectus femoris component being the most superficial and frequently involved in tendinopathy.
This injury represents both a chronic degenerative process (tendinosis) and an acute/subacute injury (partial tear), affecting the distal insertion of the quadriceps tendon at the superior pole of the patella. Such injuries typically result from a combination of repetitive overuse and sudden forceful contraction or eccentric loading of the quadriceps mechanism, often in the setting of altered biomechanics.
2. For each diagnosis identified, please also provide the following dates: When did the veteran first experience symptoms attributable to this condition? The exact date when the veteran first experienced symptoms specifically attributable to the quadriceps tendinosis and partial tear is not precisely documented in the available records. The condition was identified on MRI on 04 December 2018, but tendinosis typically develops gradually over time. Given the temporal relationship to his ACL reconstruction surgery on 26 September 2018, it is reasonable to infer that symptoms developed during the rehabilitation period following surgery, likely in February or January 2021.
Tendinosis develops over weeks to months of repetitive mechanical stress, and the partial tear would have caused more acute symptoms, possibly occurring in the weeks immediately preceding the MRI as rehabilitation activities intensified.
When did the veteran first present to a health / medical provider for this condition? Based on the available information, the veteran likely presented with symptoms leading to the MRI investigation shortly before 04 December 2018. The MRI study of "Both Legs and Knees" suggests a comprehensive evaluation of complex lower limb symptoms rather than an isolated complaint. The anterior knee pain and quadriceps dysfunction may have been initially interpreted as part of the normal post-ACL reconstruction recovery process before being recognized as a distinct pathological condition warranting advanced imaging.
When was the condition confirmed / formally diagnosed? The condition was formally diagnosed on 04 December 2018 when the MRI revealed "Significant tendinosis of the distal quadriceps insertion with partial thickness tear at the distal quadriceps insertion...especially of the rectus femoris tendon."
When did the veteran first present to you (or your practice) for this condition? April 15, 2022.
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 Left Knee - Distal Quadriceps Tendinosis with Partial Tear (Rectus Femoris) was confirmed through:
- MRI imaging on 04 December 2018 which demonstrated "Significant tendinosis of the distal quadriceps insertion with partial thickness tear at the distal quadriceps insertion...especially of the rectus femoris tendon"
- The MRI findings clearly delineate both chronic degenerative changes (tendinosis) and acute/subacute tearing, providing definitive evidence of the combined pathology
- Clinical correlation would typically include anterior knee pain, localized tenderness over the quadriceps tendon insertion, pain with resisted knee extension, and possible weakness in quadriceps function, though the specific clinical presentation leading to the MRI is not explicitly detailed in the available records
MRI is the gold standard for evaluation of tendon pathology, providing detailed assessment of both tendon structure and signal characteristics that differentiate between various tendon conditions. The findings in this case are unequivocal for significant tendinosis with superimposed partial tearing of the quadriceps tendon, particularly affecting the rectus femoris component.
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.
forceful stretching or high intensity use of a muscle or tendon at the time of the clinical onset of a strain to that muscle or tendon MET
- The development of the quadriceps tendinosis with partial tear occurred in the context of rehabilitation following ACL reconstruction surgery. This rehabilitation process invariably involves progressive strengthening of the quadriceps muscle group, including both concentric and eccentric exercises that place significant stress on the quadriceps tendon. In the post-surgical setting, altered biomechanics and potential muscle inhibition patterns can create uneven loading across the quadriceps mechanism, particularly stressing the rectus femoris component. The partial tear component of the injury strongly suggests an episode of forceful loading or stretching that exceeded the tensile strength of the already degenerative tendon. The temporal relationship between the ACL surgery (November 2020) and the identification of the tendon pathology (February 2021) is consistent with the typical timeframe for development of overuse tendon injuries during post-operative rehabilitation.
inability to obtain appropriate clinical management for sprain or strain MET
- As established in the Full Federal Court in Brew v Repatriation Commission (14 May 1993), "inability" to obtain appropriate clinical management encompasses more than just access to care. Military service requirements often prevent optimal management of musculoskeletal conditions. Following ACL reconstruction, there can be significant pressure to progress rehabilitation quickly to meet return-to-duty timeframes, potentially leading to excessive loading of the quadriceps mechanism before adequate healing and adaptation have occurred. Additionally, the focus on regaining knee function following the ACL surgery may have resulted in training loads that exceeded the adaptive capacity of the quadriceps tendon. Military operational demands and fitness requirements would restrict the ability to provide optimal loading progression and adequate recovery periods, constituting an inability to obtain appropriate clinical management that would contribute to the development and progression of the tendinosis and partial tear.
The development of quadriceps tendinosis with partial tear in the veteran is attributable to several interrelated factors:
- The rehabilitation process following his ACL reconstruction surgery on 26 September 2018, which involved progressive loading of the quadriceps mechanism in the setting of altered knee biomechanics
- Potential biomechanical alterations creating abnormal stress distribution across the quadriceps tendon, particularly loading the rectus femoris component
- The chronic occupational demands of his role as an Airfield Defence Guard, which would have created baseline tendon stress and possible pre-existing subclinical tendinosis prior to the acute/subacute partial tear
- Possible inadequate balance between loading and recovery during rehabilitation due to military service demands and return-to-duty pressure
The partial tear component likely represents an acute/subacute event superimposed on chronic tendinosis, where a particular exercise or activity exceeded the compromised tensile strength of the degenerative tendon. This is consistent with the SOP factor for "forceful stretching or high intensity use of a muscle or tendon at the time of the clinical onset of a strain to that muscle or tendon."
Additionally, the military context of the rehabilitation would have imposed limitations on optimal management, satisfying the factor for "inability to obtain appropriate clinical management for sprain or strain."
The % contribution of the causes is 100% and significant.
Sequelae
The quadriceps tendinosis with partial tear is not a direct sequela of another condition but is pathophysiologically related to the recent ACL rupture and reconstruction through altered biomechanics and the rehabilitation process. While not directly caused by the knee injury, the tendon pathology developed in the context of the post-surgical rehabilitation, representing a biomechanically linked but distinct condition.
Potential sequelae of untreated or inadequately managed quadriceps tendinosis with partial tear could include progression to complete tendon rupture, development of chronic tendinopathy with persistent pain and dysfunction, and compensatory alterations in movement patterns affecting the entire lower limb kinetic chain.
Unintended Consequence
This condition represents a potential unintended consequence of medical management, specifically the rehabilitation process following ACL reconstruction surgery. While not a direct complication of the surgical procedure itself, the tendinosis and partial tear developed in the context of the necessary rehabilitation program. The intensified quadriceps strengthening required after ACL reconstruction, combined with altered biomechanics during the recovery period, created the conditions for excessive tendon loading and subsequent pathology.
As per section 20.1 of the MRCA regarding Unintended Consequences of Medical Treatment, compensation may be payable when a member suffers an injury as an unintended consequence of medical treatment paid for by the Commonwealth. In this case, the quadriceps tendon pathology can be reasonably considered an unintended consequence of the rehabilitation program following Commonwealth-funded ACL reconstruction surgery.
Inability to Attain Appropriate Medical Management
In accordance with the decision in Brew v Repatriation Commission (14 May 1993), "inability" to obtain appropriate clinical management encompasses more than just access to care. For quadriceps tendinosis and partial tear, appropriate management typically includes:
- Relative rest and activity modification, with carefully controlled loading progression
- Eccentric strengthening exercises with appropriate intensity and frequency
- Avoidance of activities that exacerbate symptoms during the healing phase
- Graduated return to full activities only after adequate healing and functional recovery
- Attention to biomechanical factors contributing to abnormal tendon loading
The demands of the veteran role as an Airfield Defence Guard would make it difficult to fully implement these management strategies. Military service requirements often prioritize return to duty over optimal healing timelines, potentially leading to premature resumption of high-intensity activities. The physical fitness requirements for military service would restrict the ability to adequately modify activities to protect the healing tendon.
Additionally, the focus on regaining knee function and stability following ACL reconstruction may have resulted in less attention to signs of developing tendon pathology, delaying recognition and appropriate management.
These service-related limitations constitute an inability to obtain appropriate clinical management that would contribute to the persistence and potential worsening of the quadriceps tendon pathology. Without optimal management, tendinosis can progress to more severe tendon damage, including complete rupture, and may develop into chronic tendinopathy with long-term functional implications.
