Master Ritesh, an 8 year old boy, 1st order child born of a non-consanguineous marriage from Guwahati, Assam presented with complaints of painful swelling, local warmth, and inability to move or bear weight on the right knee joint for 1 day following a minor stumble, and a history of prolonged oozing of blood from minor cuts and recurrent joint swellings since toddlerhood.

HOPI

The history is dated back to yesterday morning when the child tripped while walking in the schoolyard.

• Current Acute Episode (Acute Right Knee Hemarthrosis):
  • Tripped over a step yesterday morning; did not sustain any skin cuts or visible bruises.
  • Within 4 to 6 hours, the child felt a dull ache followed by severe, throbbing pain in the right knee joint.
  • The knee became rapidly swollen, hot to the touch, and held in a semi-flexed position.
  • Child is completely unable to straighten the leg, bend the knee, or bear any weight on the right foot Points to acute intra-articular bleeding (hemarthrosis) distending the synovial capsule under high pressure.
• Past Bleeding & Target Joint History:
  • First bleeding episode occurred at 10 months of age when he had prolonged oozing for 3 days following accidental laceration of the upper labial frenulum while learning to walk.
  • At 2 years of age, he developed a massive, deep intramuscular hematoma in the right calf muscle after a minor fall, requiring hospital admission.
  • Over the past 3 years, the child has suffered recurrent painful swellings of the right knee (4 episodes) and left ankle (2 episodes).
  • The right knee has become chronically thickened and difficult to fully extend (target joint with early chronic hemophilic arthropathy) Recurrent intra-articular bleeding leads to synovial hemosiderin deposition, chronic inflammatory synovitis, neo-angiogenesis, cartilage degradation, and subchondral cyst formation.
• Nature of Bleeding:
  • Bleeding has always been deep-seated (joints and muscles) and persistent, often starting hours after injury (delayed oozing).
  • Never had petechial rashes, pinpoint skin spots, or spontaneous hematuria.
• Factor Therapy & Exposure:
  • Received episodic plasma-derived / recombinant Factor VIII concentrate during prior joint bleeds (~15 lifetime exposure days).
  • No history of allergic reactions to factor infusion; bleeding has previously responded promptly to factor administration.
• Negative History:
  • No history of severe headache, persistent vomiting, altered sensorium, irritability, or seizures Critical negative: rules out intracranial hemorrhage, the leading cause of bleeding-related mortality in hemophilia.
  • No history of groin/hip pain with inability to extend the hip Rules out acute retroperitoneal / iliopsoas hematoma with femoral nerve compression.
  • No history of neck swelling, difficulty swallowing, or stridor Rules out life-threatening retropharyngeal hematoma.
  • No history of dark black stools (melena), vomiting blood (hematemesis), or red urine.
  • No history of taking aspirin, brufen, or other NSAIDs.

Past History

• Diagnosed with Severe Hemophilia A at 2 years of age following calf hematoma.
• Managed on "on-demand" episodic factor replacement due to financial constraints (has not been on regular prophylaxis).

Family history

• Born of a non-consanguineous marriage.
• Father 36 years, healthy. Mother 32 years, completely asymptomatic (obligate / confirmed carrier).
• Younger sister (5 years old) is asymptomatic (at-risk carrier).
• Maternal Lineage (X-linked Recessive Pattern):
  • Maternal uncle (mother's brother, 28 years) has severe hemophilia A with severe crippling bilateral knee arthropathy.
  • Maternal grandfather died at 45 years of age due to severe uncontrollable bleeding following a dental extraction.

Immunization history

• Received all routine vaccines up to age as per the UIP.
• All vaccines were administered subcutaneously using a fine 25-gauge needle, followed by firm manual pressure for 5 minutes without rubbing (preventing deep intramuscular hematomas).
• Completely immunized against Hepatitis B (3 doses + booster) and Hepatitis A.

Dietary history

• Consumes a mixed northeastern Indian home diet consisting of rice, fish, eggs, and seasonal vegetables.

Food Item	Quantity	Calories (kcal)	Protein (g)
Boiled Rice	200 g	260	5.2
Fish Curry (Rohu)	60 g fish	80	11.5
Dal	1 bowl	100	6.0
Vegetable Stir Fry	1 bowl	90	1.8
Boiled Egg (1)	50 g	75	6.2
Total Observed Daily Intake	—	605 kcal	30.7 g

24-Hour Recall Deficit Analysis

$$ \text{Ideal Body Weight (IBW for 8 years, 50th centile WHO)} = 25.3\text{ kg} $$

Nutrient	Expected Intake (ICMR-NIN 2024 for IBW 25.3 kg)	Observed Intake	Deficit	Percentage Deficit
Energy (kcal)	$25.3\text{ kg} \times 65\text{ kcal/kg} = 1645\text{ kcal}$	605 kcal	1040 kcal	63.2% Deficit
Protein (g)	$25.3\text{ kg} \times 1.0\text{ g/kg} = 25.3\text{ g}$	30.7 g	Nil (Adequate)	0% Deficit

The expected calories and proteins should be calculated from the ideal body weight, not from current weight.

Socioeconomic and KAP

• Belongs to Modified BG Prasad Socioeconomic Class III (Middle Class).
• Lives in Guwahati near a tertiary government hospital with an active Hemophilia Treatment Centre (HTC).
• Parents are well-educated regarding hemophilia; carry a Hemophilia Identity Card; seeking access to regular factor prophylaxis or Emicizumab under government schemes.

Summary of History

Master Ritesh, an 8-year-old boy, born of non-consanguineous parents with an X-linked maternal family history of bleeding disorders from Guwahati, presented with acute onset of painful tense swelling and functional disability of the right knee joint for 1 day following minor trauma, with a background history of recurrent hemarthroses involving the same right knee ("target joint"), delayed bleeding from lacerations, and prior factor VIII therapy, without superficial purpura, head trauma symptoms, or systemic bleeding.

I would like to think of an inherited coagulation factor deficiency, specifically Severe Hemophilia A (Factor VIII Deficiency), presenting with an Acute Right Knee Hemarthrosis superimposed on Chronic Hemophilic Arthropathy of the Right Knee (Target Joint), without evidence of life-threatening intracranial or internal hemorrhage.

General head to toe examination

• Child Behavioral State: Child is alert, cooperative, lying supine with right lower limb supported on a pillow, grimacing with movement due to right knee pain.
• Vitals:
  • Pulse Rate: 96 beats/minute, regular, normal volume.
  • Respiratory Rate: 20 breaths/minute, regular.
  • Blood Pressure: $100/64\text{ mmHg}$ ($50^{\text{th}}$ centile for height and age).
  • Temperature: $37.0^\circ\text{C}$ (afebrile).
• Anthropometry:

Parameter	Observed	Expected (50th WHO)	Z-score / Centile	Inference
Weight	24.8 kg	25.3 kg	$50^{\text{th}}\text{ centile}$	Normal nutritional status
Height	127 cm	128 cm	$50^{\text{th}}\text{ centile}$	Normal stature

• General Physical Findings:
  • Crucial Negatives: NO pallor, NO icterus, NO petechiae, NO ecchymoses, NO mucosal bleeding, NO gingival bleeding, NO palpable purpura.
  • Lymphadenopathy / Edema / Cyanosis / Clubbing: Completely absent.
  • Oropharynx clear; no retropharyngeal bulge or airway compromise.

Systemic Examination

Musculoskeletal Examination: Right Knee Joint vs Normal Left Knee

• Inspection:
  • Right lower limb held in an antalgic attitude of ~30 degrees flexion (position of maximum joint capsule capacity).
  • Gross tense swelling of the entire right knee joint with complete obliteration of normal parapatellar depressions and suprapatellar pouch.
  • Overlying skin is tense, smooth, and shiny; no open wounds, no cuts, no superficial ecchymoses.
  • Muscle Wasting: Evident wasting of the right quadriceps muscle belly compared to the left thigh.
• Palpation:
  • Marked local warmth over the right knee compared to the normal left knee.
  • Intense tenderness elicited on gentle palpation over the joint line, patella, and suprapatellar pouch.
  • Patellar Tap Test: Positive (patella floats and taps against the femoral condyle, confirming marked intra-articular effusion).
  • Fluctuation Test: Cross-fluctuation across the joint space is positive.
  • Periarticular synovial thickening palpable along the joint margins (chronic synovitis).
• Measurements (Comparative):
  • Circumference at Mid-Patella: Right Knee = $31.5\text{ cm}$ | Left Knee = $26.8\text{ cm}$ ($+4.7\text{ cm}$ enlargement from acute hemarthrosis).
  • Thigh Girth (10 cm above patella): Right Thigh = $31.0\text{ cm}$ | Left Thigh = $33.5\text{ cm}$ ($2.5\text{ cm}$ quadriceps atrophy due to chronic disuse).
• Range of Movement (ROM):
  • Active and passive movements are severely restricted and excruciatingly painful; flexion beyond 30 degrees and extension to 0 degrees are resisted (fixed flexion deformity of ~5 degrees present).
• Other Joints: Left knee, bilateral ankles, elbows, and wrists show normal contour, no effusion, and full range of movement.

Central Nervous System (CNS)

• Conscious, oriented, clear speech.
• Cranial nerves I-XII clinically intact.
• Motor System (Upper Limbs & Left Lower Limb): Normal bulk, tone, and power (5/5); DTRs $2+$; plantars flexor bilaterally.
• Meningeal Signs: Absent. Fundoscopy: Normal discs, no retinal hemorrhages.

Abdomen & Other Systems

• Abdomen soft, non-tender; no hepatomegaly, no splenomegaly; renal angles non-tender.
• Psoas sign negative (no pain on hyperextension of hip, rules out iliopsoas hematoma).
• CVS & RS completely normal.

Summary

Master Ritesh, an 8-year-old boy, born of non-consanguineous parents with an X-linked maternal pedigree of bleeding disorders from Guwahati, presented with an acute onset of painful, hot, tense swelling and total immobility of the right knee joint for 1 day following a trivial stumble, on a background history of recurrent hemarthroses and target joint involvement. Examination demonstrates an acute right knee hemarthrosis (joint circumference $+4.7\text{ cm}$, positive patellar tap, local warmth, antalgic flexion), chronic quadriceps muscle atrophy ($2.5\text{ cm}$), and early arthropathy, without superficial petechiae, systemic bleeding, or neurological deficits.

The clinical findings are classic for Severe Hemophilia A (Congenital Factor VIII Deficiency), presenting with an Acute Right Knee Hemarthrosis involving a known Target Joint, with early Chronic Hemophilic Arthropathy.

Differential Diagnosis

Disease	Points IN FAVOR	Points AGAINST
Severe Hemophilia A (Factor VIII Deficiency)	Male, X-linked maternal inheritance, deep hemarthrosis, target joint, prolonged aPTT with normal PT, Factor VIII <1%	Primary Diagnosis
Hemophilia B (Factor IX Deficiency / Christmas Disease)	Identical clinical presentation, deep hemarthroses, X-linked recessive	Indistinguishable clinically; differentiated strictly by specific factor assays (Factor IX deficient in Hemophilia B, normal in Hemophilia A)
Severe von Willebrand Disease (Type 3 / Severe Type 2)	Bleeding disorder, can present with hemarthrosis if FVIII is severely secondary depleted	Autosomal inheritance (affects both sexes equally), predominantly mucosal/cutaneous bleeding, prolonged Bleeding Time (BT) / abnormal PFA-100, markedly reduced vWF:Ag
Factor XI Deficiency (Hemophilia C)	Coagulation defect, prolonged aPTT	Autosomal recessive (equal sex ratio), spontaneous hemarthroses are exceptionally rare; bleeds only post-surgery/trauma
Septic Arthritis of the Knee	Acute painful knee swelling, local warmth, immobility	Associated with high spiking fever, toxic appearance, leukocytosis, elevated CRP/ESR; clear history of hemophilia and trauma points to hemarthrosis
Juvenile Idiopathic Arthritis (Oligoarticular JIA)	Monoarthritis of the knee joint in a child	Insidious onset, morning stiffness, lack of severe throbbing pain, normal coagulation parameters, no X-linked bleeding history

Investigation Protocol & Diagnostic Workup

flowchart TD
    A["Male Child with Acute Hemarthrosis & Prolonged Bleeding"] --> B["Coagulation Screen: Platelet Count, PT/INR, aPTT & Bleeding Time"]
    B --> C{"Isolated Markedly Prolonged aPTT with Normal PT & Platelets?"}
    C -->|Yes| D["50:50 Mixing Study (Incubated Patient Plasma + Normal Plasma)"]
    C -->|No / Both Prolonged| E["Workup for Liver Disease, Vit K Deficiency, or DIC"]
    D --> F{"Complete Correction of aPTT to Normal?"}
    F -->|Corrects| G["Confirms Factor Deficiency: Measure Factor VIII:C & Factor IX:C"]
    F -->|Fails to Correct| H["Workup for Acquired Inhibitor / Lupus Anticoagulant (Bethesda Assay)"]
    G --> I{"Factor VIII:C < 1% with Normal Factor IX?"}
    I -->|Yes| J["Confirm Severe Hemophilia A: Screen for Inhibitors (< 0.4 BU) & MSK-USG"]

1. Coagulation Screening Battery

• Platelet Count: $285,000/\mu\text{L}$ (normal).
• Prothrombin Time (PT / INR): Normal ($12.2\text{ seconds}$, Control $12.0\text{ s}$, INR 1.0) — confirms extrinsic and common pathways are intact.
• Activated Partial Thromboplastin Time (aPTT): Markedly Prolonged at $78.0\text{ seconds}$ (Control $28-32\text{ seconds}$) — confirms an isolated intrinsic pathway coagulation defect.
• Bleeding Time (BT) / PFA-100 Closure Time: Normal (normal primary hemostasis; excludes von Willebrand disease and platelet dysfunction).
• Thrombin Time (TT): Normal ($15.0\text{ seconds}$).

2. 50:50 Plasma Mixing Study (Correction Test)

• Patient's plasma is mixed $1:1$ with normal pooled plasma and incubated at $37^\circ\text{C}$ for 2 hours.
• Result: aPTT completely corrects to normal ($30.5\text{ seconds}$).
• Inference: Confirms a true coagulation factor deficiency and excludes the presence of an immediate-acting or time-dependent circulating factor inhibitor.

3. Confirmatory Specific Coagulation Factor Assays

• Factor VIII Coagulant Activity (FVIII:C): $<1.0\%$ ($<0.01\text{ IU/mL}$) — Confirms Severe Hemophilia A.
  • Severity Stratification:
    • Severe: $<1\%$ of normal ($<0.01\text{ IU/mL}$) — spontaneous bleeds into joints and muscles.
    • Moderate: $1-5\%$ of normal ($0.01-0.05\text{ IU/mL}$) — bleeds with minor trauma.
    • Mild: $>5-40\%$ of normal ($0.05-0.40\text{ IU/mL}$) — bleeds only with major trauma or surgery.
• Factor IX Coagulant Activity (FIX:C): Normal at $92\%$ (excludes Hemophilia B).
• von Willebrand Factor Studies: vWF Antigen ($105\%$) and Ristocetin Cofactor Activity ($98\%$) are normal.

4. Inhibitor Screening

• Bethesda Assay (Nijmegen Modification): Negative ($<0.4\text{ Bethesda Units / BU}$) — confirms absence of neutralising anti-Factor VIII alloantibodies.

5. Imaging of the Affected Joint

• Point-of-Care Ultrasound (POCUS / MSK-USG Right Knee):
  • Demonstrates marked anechoic to complex hypoechoic suprapatellar joint effusion with thickened, hypervascular synovial folds (HEAD-US score $4/8$).
• Plain Radiograph of Right Knee (AP and Lateral):
  • Demonstrates soft tissue distension, periarticular osteopenia, widening of the intercondylar notch, and subtle subchondral irregularity (Arnold-Hilgartner Stage II Hemophilic Arthropathy).

Management Plan

1. Acute Hemarthrosis: Immediate Factor VIII Replacement Therapy

• Treatment Principle: Treat immediately upon suspicion; NEVER delay factor infusion for radiological imaging or laboratory confirmation.
• Factor VIII Dose Calculation Formula:

$$ \text{Required Factor VIII Units} = \text{Body Weight (kg)} \times \text{Desired Factor Rise (\%)} \times 0.5 $$

• For an Acute Hemarthrosis, the target desired factor rise is $40\% - 60\%$.
• Calculation for Master Ritesh (Weight 25.0 kg):

$$ \text{Dose} = 25.0\text{ kg} \times 50\% \times 0.5 = 625\text{ Units of Factor VIII} $$

• Prescription: Administer $650\text{ Units}$ (or $25\text{ U/kg}$) of Recombinant or Plasma-Derived Factor VIII Concentrate as an immediate intravenous push over 5 minutes.
• Maintenance Dosing: Re-dose at $20-25\text{ U/kg}$ every 12 hours for 24–48 hours until acute pain, warmth, and joint swelling significantly regress.

2. Adjunctive Joint Management: The PRICE Protocol

• P — Protection: Splint the right knee in comfortable 20-30 degree antalgic flexion using a padded posterior plaster slab or removable knee brace.
• R — Rest: Strict bed rest; avoid all weight bearing on the affected limb.
• I — Ice: Apply cold packs wrapped in a towel for 15–20 minutes every 4 to 6 hours (causes vasoconstriction and numbs pain).
• C — Compression: Gentle elastic crepe bandage wrapping (avoid tight circumferential constriction).
• E — Elevation: Elevate the right lower limb on pillows above heart level to enhance venous and lymphatic drainage.
• Analgesia: Prescribe Oral Paracetamol ($15\text{ mg/kg/dose}$ q6h) or Tramadol for severe pain. STRICTLY PROHIBIT Aspirin and NSAIDs (Ibuprofen/Diclofenac) due to irreversible platelet inhibition.

3. Rehabilitation & Physiotherapy

• As soon as acute pain and swelling subside under factor coverage (usually day 2–3), initiate supervised isometric quadriceps strengthening exercises and active-assisted range of motion.
• Clinical Rationale: Prompt rehabilitation prevents arthrofibrosis, capsular contracture, and worsening quadriceps atrophy.

4. Long-Term Regular Prophylaxis (Standard of Care - WFH 2020 Guidelines)

• Transition from episodic "on-demand" treatment to Regular Primary/Secondary Prophylaxis:
  • Standard Factor VIII Prophylaxis: Intravenous Recombinant Factor VIII at $25-40\text{ U/kg}$ administered 3 times weekly (or every other day) to maintain trough factor VIII levels consistently $>1-3\%$.
  • Novel Non-Factor Prophylaxis (Emicizumab - Hemlibra):
    • Humanized bispecific monoclonal antibody that bridges activated Factor IX and Factor X, restoring the function of missing Factor VIII.
    • Dosage: $3.0\text{ mg/kg}$ subcutaneously once weekly for 4 weeks (loading dose), followed by maintenance therapy of $1.5\text{ mg/kg}$ subcutaneously once weekly (or $3.0\text{ mg/kg}$ every 2 weeks).
    • Advantages: Subcutaneous administration (eliminates venous access difficulties), constant hemostatic protection, and equal efficacy in patients with or without Factor VIII inhibitors.

5. Comprehensive Hemophilia Care & Family Guidance

• Provide a durable Hemophilia Medical Alert Card / Bracelet indicating diagnosis, factor deficiency, and emergency contact numbers.
• Avoid Intramuscular Injections: All future immunizations and medications must be administered subcutaneously or orally.
• Dental Hygiene: Meticulous dental care to prevent caries and avoid dental extractions; co-prescribe oral Tranexamic acid ($15-20\text{ mg/kg/dose}$ tid for 5 days) for any minor mucosal or dental oozing (antifibrinolytic).
• Family Screening: Provide genetic counseling; perform carrier testing for the mother and 5-year-old younger sister.