Chapter 10 Joint pain and swelling in adolescence

Case 10.1

1. Using only this information, list the possible causes of James’s presenting symptom(s). Justify your answer.

Possible cause	Justification
DDx 1: osteochondroses (Osgood-Schlatter disease)	• Within expected age range for males (10–15 yrs) • Site of pain inferior to patella over tibial tuberosity • Pain aggravated with activities (squatting, jumping) • Relief with rest and activity modification • Insidious onset and intermittent history • Bilateral pain
DDx 2: patellar tendonitis and/or Sinding-Larsen-Johansson disease	• Overuse due to repetitive sporting activities • Occurs in adolescents during growth spurts • Pain is tibial tuberosity in origin, not patella, so less likely • Aggravated by running, jumping, twisting • Relieved by rest • May limp after exercise
DDx 3: infection (osteomyelitis)	• Insidious onset • Local swelling at site of pain, but no joint effusion • No fever or constitutional changes so less likely • Expect painful restriction of joint range of motion and positive laboratory testing
DDx 4: neoplasm (less likely)	• Insidious onset for no apparent reason • Bilateral presentation makes it unlikely • Intermittent pain and relieved by rest make it unlikely • No constitutional changes make it unlikely • Relatively uncommon so less likely
DDx 5: trauma — tibial tuberosity fracture (less likely)	• Unlikely — no history of trauma • Unlikely — pain relieved with rest

2. Why was James asked about:

a the quality of the pain

The type of pain is important as it helps the practitioner to differentiate, or to be more specific about the tissues, structures, or alternatively the underlying process that may be involved. For example, a vague ache may indicate an inflammatory process or a visceral structure; a stabbing sharp pain in the muscle may indicate a muscle tear; or a radicular shooting pain may indicate involvement of a neural structure.

b the site of the pain

The site of pain is significant because again it helps determine the structure that is involved in the process. The site of pain may be superficial or deep, or local or diffuse.

c the significance of swelling

Swelling refers to the transient abnormal enlargement or increase in volume of a body part, usually due to fluid accumulation. The presence of swelling usually indicates damage to the underlying tissue, causing inflammation, bleeding or a lymphatic drainage problem. The sudden onset of painful swelling may indicate haemarthrosis. Swelling may also indicate synovial effusion from joint injury to meniscus or ligaments, or may be a result of bursal injury. In this case, the presence of localised swelling over the tibial tuberosity may indicates soft tissue swelling that occurs as a result of the underlying pathological process (osteochondrosis) that is taking place at the tibial tuberosity.

d the significance of clicking, locking or giving way

Questioning the patient on these particulars will aid in narrowing down the exact structures that may be involved in causing the patient’s pain/symptoms. Clicking is usually due to interruption in the meniscal tissue, a loose intra-articular body or an incorrect tracking of the patella within its femoral groove, although can occur in normal joints during certain activities such as squatting. Locking refers to the sudden inability to fully extend the knee (flexion remains normal). The main causes for locking include torn meniscus, loose body, torn anterior cruciate ligament or dislocated patella.^[1] Giving way usually indicates a feeling of instability of the knee joint; the main causes include cruciate or collateral ligament rupture, patella dysfunction, meniscus injury, or loose bodies within the joint.

e the significance of activities that aggravate the pain

Aggravating factors again help the practitioner differentiate which structures may be involved in causing the patient’s pain or symptoms, and particularly the exact biomechanics involved that may be affecting the injured tissue, which further aids in determining the specific structure involved. For example, pain on movement may indicate involvement of muscles or tendons; squatting involves knee flexion and stretching of the quadriceps muscles, which in this case places pressure on the tibial tuberosity at the attachment of the patella tendon.

3. What do you need to examine in this patient?

Examination	Justification
Gait	Assess for orthopaedic gait, look for biomechanical dysfunction, weakness
Inspection	Note swelling, effusion, scars, deformities, atrophy; particular attention to enlargement or prominence of tibial tuberosity
Palpation	For presence of fluid, warmth, swelling, clicking, tenderness, crepitus, joint line tenderness; particular attention to swelling and tenderness at tibial tuberosity. Palpate for muscle hypertonicity, particularly hamstrings
Tests for swelling	Bulge test, patella tap test to determine amount and type of swelling present
Orthopaedic tests	For ligamentous instability, meniscus injury, patella tracking signs and pain provocation
Resisted knee extension	For pain provocation, mimics aggravating activities
Knee range of motion	Should be normal unless capsular injury or muscle/tendon/ligament injury
Neurovascular examination of lower extremity	Should be normal unless severe effusion compromises drainage
Musculoskeletal assessment of hip, ankle and lumbar spine	Should be normal

4. What information can you obtain from these findings? Can you narrow your differential diagnosis?

The most significant finding with James is the localised, bilateral symmetrical point tenderness, enlargement and swelling over the right and left tibial tuberosities. This is supported by the resisted knee contraction test which places extra pressure on tibial tuberosity via traction through the patellar ligament/quadriceps muscle. The lack of orthopaedic findings indicate that involvement of cruciate/collateral ligaments, meniscus or patellar tracking dysfunction is unlikely. The most likely diagnosis is Osgood-Schlatter disease. All other differential diagnoses are less likely as the patient does not display any constitutional changes (vitals are normal) and has not suffered any trauma.

5. Explain the significance of the following signs, in context of your differential diagnosis:

a blood pressure, respiration, pulse and temperature

This patient shows vital signs that are completely within the normal range for a 12-year-old child. An elevation of temperature may indicate underlying infection. Alteration in respiration can often occur due to pain or anxiety; this patient does not present any overt signs of extreme pain — his pain is vague unless provoked by aggravating activities.

b enlargement of the tibial tuberosity bilaterally

Prominence of the tibial tuberosity in children is usually an indication of Osgood-Schlatter disease, where repeated traction to anterior portion of the developing ossification centre of the tibial tubercle leads to microavulsion injury which causes reparative new bone to be laid down, causing elevation of the tibial tubercle.^[2]

c tenderness of the tibial tuberosity

Point tenderness over the tibial tuberosity in children is another sign of Osgood-Schlatter disease.

d pain with resisted knee extension

Knee extension requires activation of the quadriceps group of muscles, which attach proximally to the pelvis and proximal femur, and attach distally via the base of the patella and patellar ligament to the tibial tuberosity. Resisted movements are performed to properly test the muscles.^[3] Resisted knee extension in this case places traction force on the tibial tuberosity via the patellar ligament, causing pain due to the underlying damage occurring to apophysis of tibial tuberosity. Osgood-Schlatter disease is thought to be due to microavulsions/extra-articular osteochondral stress fractures occurring during activities such as running or kicking that require repeated quadriceps contraction.

6. What investigations are required? Why? What would you expect, based on the physical examination findings?

Investigation	Justification	Expectations based on differential diagnosis
Radiographs	• Lateral projection preferred view to show tibial tuberosity in optimal position	• May appear normal, especially if child is in preossification phase ^[2] • Acute phase may show prominence of tibial tuberosity with or without anterior soft tissue swelling • Elevation of the apophysis • Severe cases may show bone fragmentation or irregularity ^[2]
Ultrasound	• Assess patellar ligament and hypoechoic area of adjacent soft tissue	• May reveal normal tubercle • Often signals changes consistent with thickening of the patellar ligament
Computed tomography (CT) scan and/or magnetic resonance imaging (MRI)	• View tibial tuberosity and surrounding soft tissue	• May show changes at patellar ligament insertion