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To enhance your diagnostic reasoning skills, follow these steps:
- Review the Information: Carefully read through the content in each section of the case scenario.
- Consider the Question: Reflect on the Diagnostic Reasoning Question presented. Take your time to think about your answer.
- Compare Your Answer: Attempt to answer the question before viewing our suggested answer. When ready, click “View Suggested Answer” to compare it with your own.
Repeat these steps for each section of the case scenario. Please note that the suggested answers are only indicative and not exhaustive. They serve as guidelines and should not be considered complete answers.
Patient’s History
In the sections below, you will find case history information designed to guide you through a systematic approach to performing a focused and relevant case history. This process will help you narrow down the potential causes of the patient’s complaint. As you go through the material, we encourage you to answer the questions provided to test and enhance your diagnostic reasoning skills.
Who is the patient and where is the pain?
When was the onset and what caused the onset?
Mark is a 26-year-old taxi driver who has a sudden onset of right lateral knee pain. He specifically points to the region of the fibular head as the site of discomfort. His pain began four days ago during a friendly football game when he landed awkwardly and immediately felt a sharp pain in his knee.
Diagnostic Reasoning Question
What are the differential diagnoses you would consider for Mark’s knee pain?
ViewHide Suggested Answer
- Lateral meniscus tear
- Iliotibial band syndrome
- Lateral collateral ligament sprain
- Popliteus or biceps femoris tendonitis
- Proximal tibiofibular joint sprain or dysfunction
- Posterolateral corner injuries
- Proximal fibular fracture
In addition to the possibilities mentioned above, pre-existing conditions affecting the region could be exacerbated by an injury, such as a pathological fracture of a tumor of the proximal fibula (e.g., osteochondroma or osteosarcoma).
What are the pain characteristics?
What are the aggravating and relieving factors?
What has been the course of the pain?
Mark describes his pain as a persistent ache with occasional sharp exacerbations during specific activities. At its worst, he rates the pain intensity as an 8 out of 10. Activities that trigger a sharp, brief stab of pain include walking downstairs and squatting. The day after the injury, he noticed some swelling on the lateral side of his knee, which has since subsided. Applying ice has provided temporary relief, and he reports that the pain has eased over the past 24 hours.
Diagnostic Reasoning Question 1
How does Mark’s report of pain character and aggravating and relieving factors inform the diagnostic process?
ViewHide Suggested Answer
Mark’s pain description suggests an acute knee injury, potentially involving structures such as the ligaments, meniscus, or other soft tissues. The sharp pain triggered by activities like walking downstairs and squatting reinforces the likelihood of a mechanical injury.
Diagnostic Reasoning Question 2
How does Mark’s report of swelling inform the diagnostic process?
ViewHide Suggested Answer
The initial swelling suggests an inflammatory response, which is typical of acute injuries. Swelling localized to the lateral side of the knee may indicate inflammation of a tendon, ligament, bursa, or the tibiofibular joint capsule. If the swelling were directly over the tibiofemoral joint space, it could point to a meniscal cyst, often associated with meniscal tears. The reduction in swelling may indicate that the inflammation is subsiding. The temporary relief from applying ice suggests that local inflammation is present, potentially combined with the analgesic effect of cryotherapy.
Are there any associated symptoms?
Upon further questioning, Mark reports that he has not noticed any clicking sensations in his right knee. However, since the onset of the knee pain, he has experienced tightness and discomfort in the back of his right thigh and posterior pelvis. Additionally, he has noticed an inability to fully straighten his right knee, particularly when seated.
Diagnostic Reasoning Question 1
How does the absence of clicking in the knee inform the diagnostic process?
ViewHide Suggested Answer
This can be an important detail because clicking noises in the knee can often indicate issues such as meniscal tears or cartilage damage. The absence of clicking suggests that these conditions are unlikely in this patient.
Diagnostic Reasoning Question 2
How does his report of tightness and discomfort in the back of his right thigh and posterior pelvis and inability to fully straighten his knee, especially when seated, inform the diagnostic process?
ViewHide Suggested Answer
- Tightness and discomfort in the back of the thigh and posterior pelvis may indicate secondary muscle involvement, neural involvement, or pain referral from a myofascial pain syndrome, as well as damaged ligaments or tendons.
- The inability to fully straighten the knee, particularly in a seated position, could indicate sciatic nerve involvement; however, in this patient, it is most likely due to hamstring hypertonicity, strain, or tendinopathy.
Is there any past history that may be relevant to the current complaint?
Mark recalls experiencing similar knee pain about six months ago after colliding with another player. He did not seek treatment, and the condition resolved on its own within a week.
Diagnostic Reasoning Question
How might Mark’s past history contribute to his current presentation?
ViewHide Suggested Answer
His history of a previous injury to the same area may have predisposed him to the current condition, potentially indicating underlying damage to supporting structures, such as ligaments or tendons, that may not have fully healed. This previous trauma could have weakened the area, making it more susceptible to re-injury.
Are there any red flags?
The following questions are asked to identify any “red flags” that could suggest serious pathology. Even if the patient has previously mentioned related information during the case history, it is recommended to revisit these questions to ensure a comprehensive evaluation.
- Does your pain disappear even for a short time? “Yes. The pain disappears with rest and is also relieved when I apply ice.”
- Does the pain wake you up at night? “No.”
- Do you feel weak in your legs? “No.”
- Have you recently had any fever, chills, or night sweats? “No.”
- Have you recently had any knee surgery or knee injections? “No.”
- Have you recently had an infection or other illness? “No.”
- Have you had any unexplained weight loss recently? “No.”
Diagnostic Reasoning Question
Do any of Mark’s answers raise a red flag?
ViewHide Suggested Answer
None of his responses raises a red flag.
Differential Diagnosis
Diagnostic Reasoning Question
Based on the available history, how would you prioritize the list of differential diagnoses?
ViewHide Suggested Answer
- Lateral collateral ligament sprain
- Proximal tibiofibular joint sprain or dysfunction
- Popliteus or biceps femoris tendonitis
- Posterolateral corner injuries
- Lateral meniscus tear
- Proximal fibular fracture
- Iliotibial band syndrome
Reflection Point
Pause and consider whether the key elements of a thorough and relevant patient history have been addressed. Are there any additional questions you would have asked? If so, what are they, and why would they be important?
Before reviewing the physical examination findings below, take a moment to reflect on which physical examination procedures you would perform to accurately assess this patient.
Physical Examination
In the sections below, you will find physical examination findings for this patient. The material outlines a systematic approach to conducting a focused and relevant physical examination aimed at narrowing down the potential causes of the patient’s complaint. As you review the material, we encourage you to answer the questions provided to test and enhance your clinical reasoning and diagnostic skills. Additionally, consider whether all essential elements of the physical examination have been thoroughly addressed.
Vital Signs
Mark’s vital signs are within normal limits.
Diagnostic Reasoning Question
What is the significance of normal vital signs?
ViewHide Suggested Answer
Normal vital signs typically indicate that there are no immediate life-threatening conditions. Particularly, normal temperature indicates the absence of acute infection.
Inspection
Inspection reveals mild swelling around the right fibular head, with no visible bone deformity or bruising.
Diagnostic Reasoning Question
How does the presence of mild swelling around the fibular head inform the diagnostic process?
ViewHide Suggested Answer
Mild swelling localized to the fibular head region suggests several possible conditions, including:
- Proximal tibiofibular joint sprain or dysfunction
- Biceps femoris tendinitis
- Lateral collateral ligament sprain
Range of Motion
Mark exhibits a full range of motion in both flexion and extension of the right knee but reports some lateral knee discomfort at the extremes of these movements. Resisted flexion of the right knee elicits pain around the fibular head. The range of motion examination of the right hip reveals slight restriction in flexion when performed with the knee extended, with Mark reporting tightness in the right posterolateral thigh. The lumbar spine demonstrates a full, pain-free range of motion. The right ankle’s range of motion is normal, although full passive dorsiflexion aggravates his lateral knee pain.
Diagnostic Reasoning Question 1
How do the results of his knee range of motion assessment inform the diagnostic process?
ViewHide Suggested Answer
The knee range of motion assessment indicates a mechanical issue in the lateral knee region. Pain during resisted knee flexion near the fibular head suggests possible involvement of the biceps femoris insertion or the proximal tibiofibular joint.
Diagnostic Reasoning Question 2
How do the results of the hip range of motion assessment inform the diagnostic process?
ViewHide Suggested Answer
The hip range of motion assessment indicates potential involvement of the biceps femoris muscle. Given the proximity of the proximal tibiofibular joint to the biceps femoris tendon insertion, dysfunction or inflammation in this joint could impact the muscle, leading to tightness or discomfort in the posterior thigh.
Diagnostic Reasoning Question 3
How do the results of the ankle range of motion assessment inform the diagnostic process?
ViewHide Suggested Answer
The ankle range of motion assessment suggests a possible involvement of the proximal tibiofibular joint, as full ankle dorsiflexion may cause the fibular head to shift superiorly, exacerbating pain linked to the proximal tibiofibular joint.
Palpation
During palpation, mild swelling and moderate tenderness are noted over both the anterior and posterior aspects of the proximal tibiofibular joint. There is no tenderness over Gerdy’s tubercle or along the lateral margin of the tibiofemoral joint. However, tenderness is present in the distal portion of the biceps femoris tendon, and its muscle belly feels hypertonic. Slight tenderness is also elicited on palpation of the right ischial tuberosity. A functional assessment of the right proximal tibiofibular joint reveals limited anterior glide of the fibular head.
Diagnostic Reasoning Question 1
Which conditions might cause mild swelling and moderate tenderness over both the anterior and posterior aspects of the proximal tibiofibular joint?
ViewHide Suggested Answer
Here are some potential causes:
- Proximal tibiofibular joint sprain or dysfunction
- Biceps femoris tendonitis
- Synovitis or bursitis
- Osteoarthritis or inflammatory arthritis
- Local infection
Diagnostic Reasoning Question 2
How does the absence of tenderness at Gerdy’s tubercle inform the diagnostic process?
ViewHide Suggested Answer
The absence of tenderness at Gerdy’s tubercle decreases the likelihood of injury to the distal attachment of the iliotibial band, which commonly presents with localized pain at this site.
Diagnostic Reasoning Question 3
How does the functional assessment of the proximal tibiofibular joint, combined with the biceps femoris findings, inform the diagnostic process?
ViewHide Suggested Answer
The limited anterior glide of the fibular head suggests dysfunction of the proximal tibiofibular joint. Given the joint’s proximity to the insertion of the biceps femoris tendon, any dysfunction or inflammation in this area can directly impact the biceps femoris muscle. This relationship is reflected in the observed tenderness on palpation of the distal biceps femoris tendon and the ischial tuberosity, along with muscle hypertonicity. These findings indicate that the biceps femoris is likely being affected by issues originating in the proximal tibiofibular joint.
Reflection Point
Considering the patient’s history and examination findings thus far, take a moment to reflect on which special tests would be most appropriate to further evaluate this patient.
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Special Tests
The Heel Tap test is performed and is negative, with no reproduction of the patient’s knee pain.
Diagnostic Reasoning Question
What does a negative Heel Tap test indicate?
ViewHide Suggested Answer
The Heel Tap test is designed to detect fractures in the lower extremity. A negative result in this case suggests that a proximal fibular fracture is unlikely. To see how the Heel Tap test is performed, please watch the video below.
The McMurray test is performed and yields a negative result, with no clicking or pain produced.
Diagnostic Reasoning Question
What does a negative McMurray test indicate, and why might this test be performed even if the patient’s history does not mention knee clicking?
ViewHide Suggested Answer
The McMurray test is conducted to assess for meniscal injuries. In this patient, the negative McMurray test helps to rule out the involvement of the lateral meniscus.
In patients with lateral knee pain, even in the absence of knee locking or clicking, it is still important to assess for a meniscus injury. If the McMurray test only elicits knee pain (particularly along the joint line), it may indicate a meniscal tear. If the test elicits knee pain accompanied by clicking, popping, or a sensation of the knee catching or locking, the suspicion of a meniscal tear is much stronger.
To see how the McMurray test is performed, please watch the video below.
The Ober and the Noble Compression tests are performed and found to be negative.
Diagnostic Reasoning Question
How do the negative findings for these tests inform the diagnostic process?
ViewHide Suggested Answer
Since these tests are designed to assess iliotibial band involvement, the negative results help rule out the iliotibial band’s contribution to the patient’s symptoms. Please watch the videos below to see how these tests are performed.
The Varus Stress test for the knee is performed and is found to be negative.
Diagnostic Reasoning Question
What is the Varus Stress test for the knee designed to assess?
ViewHide Suggested Answer
The Varus Stress test is designed to assess the integrity of the lateral collateral ligament (LCL). A negative result in this patient helps rule out involvement of the lateral collateral ligament. To see how the Varus Stress test is performed, please watch the video below.
The External Rotation Recurvatum test for the knee is performed and found to be negative.
Diagnostic Reasoning Question
What is the External Rotation Recurvatum test designed to assess?
ViewHide Suggested Answer
The External Rotation Recurvatum test is designed to detect posterolateral rotary instability of the knee by assessing the integrity of the posterolateral corner structures. A negative result in this patient helps rule out involvement of these structures as the cause of his lateral knee pain. To see how the External Rotation Recurvatum test is performed, please watch the video below.
The Straight Leg Raise (SLR) test is performed on the right side. As the leg is raised close to 90 degrees, the patient reports discomfort in the posterior thigh along with some aggravation of his lateral knee pain.
Diagnostic Reasoning Question
How do the results of the SLR test in this patient inform the diagnostic process?
ViewHide Suggested Answer
While the SLR test is primarily used to identify radiculopathy or sciatica, it also provides valuable information regarding hamstring tightness and hip joint mobility. In this patient, the discomfort in the posterior thigh and aggravation of lateral knee pain during the SLR test are consistent with the findings from the earlier hip range of motion assessment. These results suggest hypertonicity of the biceps femoris, potentially linked to tendinopathy at its insertion or involvement of the proximal tibiofibular joint.
To see how the Straight Leg Raise test is performed, please watch the video below.
Reflection Point
Please pause and assess whether all the essential elements of a thorough and relevant physical examination have been completed for this patient. Are there any additional procedures you would have performed? If so, why?
Imaging
Plain radiography of the knee is performed, revealing no evidence of a fibular fracture or other bone pathology.
Diagnosis
Diagnostic Reasoning Question
Based on the available information, what is the most likely diagnosis?
ViewHide Suggested Answer
Proximal tibiofibular joint sprain or dysfunction, accompanied by associated hypertonicity of the biceps femoris.
References and Suggested Further Readings
Bozkurt M. et al. The proximal tibiofibular joint: An anatomic study. Clinical Orthopaedics and Related Research. 2003, No 406, p. 136-140.
Ogden JA. The anatomy and function of the proximal tibiofibular joint. Clinical Orthopaedics and Related Research.1974, No 101, p. 186-191.
Radakovich M and Malone T. The superior tibiofibular joint: The forgotten joint. The Journal of Orthopaedic and Sports Physical Therapy. 1982, Vol 3, No 3, p. 129-132.
Beazell JR, Grindstaff TL, Magrum EM, Wilder R. Treatment of lateral knee pain by addressing tibiofibular hypomobility in a recreational runner. N Am J Sports Phys Ther. 2009;4(1):21–28.
Roxanne Caron. Mobilization Techniques for Proximal Tibiofibular Joint Dysfunction. Athletic Training and Sports Health Care. 2014;6(4):149-150.
Travell JGb, Simons DG. Myofascial pain and dysfunction: The Trigger Point Manual. Baltimore: Williams and Wilkins.
Srbely JZ, Dickey JP, Lowerison M, Edwards AM, Nolet PS, Wong LL. Stimulation of myofascial trigger points with ultrasound induces segmental antinociceptive effects: A randomized controlled study. Pain. 2008 Oct 15;139(2):260–6.
Watson T. Ultrasound therapy. www.electrotherapy.org/modality/ultrasound-therapy.
Watson T. Laser Therapy. www.electrotherapy.org/modality/laser-therapy.
Baxter, D. (2008) Low Intensity Laser Therapy. Chapter 11 in : Electrotherapy : Evidence Based Practice.
Draper, D. O. et al. (2010). “Thermal ultrasound decreases tissue stiffness of trigger points in upper trapezius muscles.” Physiotherapy Theory and Practice 26(3): 167-172.
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Disclaimer: The acemsk.com website (including text, graphics, downloadable resources, and videos) is intended to provide general health information for educational purposes only. This information is not a substitute for personal consultation with a qualified healthcare professional. Always seek the advice of a healthcare professional for any questions regarding your condition, symptoms, and appropriate treatments.
Copyright © Educom Pty Ltd: All content on the acemsk.com website, including text, graphics, videos, and downloadable files, is the property of Educom Continuing Education, a division of Educom Pty Ltd, and is protected by copyright and other intellectual property laws under international conventions. Unauthorized use or duplication of this material without express written permission from Educom Pty Ltd is strictly prohibited.
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