5.2 Burn Classification & PT Considerations
Key Takeaways
- Burns are classified by depth as superficial, superficial partial-thickness, deep partial-thickness, full-thickness, and subdermal, with healing time and scarring risk rising as depth increases.
- Adult Rule of 9s assigns 9% Total Body Surface Area (TBSA) to the head, each arm, the anterior trunk, the posterior trunk, and each anterior or posterior leg (18%), with 1% for the perineum.
- Anti-deformity positioning generally keeps the shoulder abducted 90 degrees, elbows extended, hands in the intrinsic-plus position, hips extended and neutral, knees extended, and ankles in neutral dorsiflexion.
- Custom compression garments are typically introduced once wounds are essentially closed and worn 23 hours per day for roughly 12 to 24 months to control hypertrophic scarring.
- PTAs report any change in graft integrity, drainage character, or pain pattern to the supervising PT before progressing range of motion or compression.
Burn Depth Classification
Burn depth determines healing time, scar risk, surgical need, and the aggressiveness of positioning and stretching the PTA can implement.
| Depth | Structures Involved | Appearance | Pain | Healing |
|---|---|---|---|---|
| Superficial | Epidermis only | Red, dry, no blisters (classic sunburn) | Painful | 3 to 7 days, no scar |
| Superficial Partial-Thickness | Epidermis and upper dermis | Moist, red, blanching, blisters | Very painful, hyperalgesic | About 7 to 21 days, minimal scar |
| Deep Partial-Thickness | Epidermis and deep dermis | Mixed red and white, wet or waxy, sluggish blanching | Painful but pinprick may be reduced | 3 to 5 weeks, hypertrophic scarring likely |
| Full-Thickness | Through dermis into subcutaneous tissue | Leathery, dry, white, brown, or charred; no blanching | Insensate at the center (sensory nerves destroyed) | Will not re-epithelialize from the center; needs grafting |
| Subdermal | Into muscle, tendon, or bone | Charred, mummified, exposed deep structures | Insensate | Requires excision and reconstruction; possible amputation |
Rule of 9s For TBSA In Adults
The Rule of 9s divides the adult body into segments of roughly 9% TBSA so that fluid resuscitation needs and burn severity can be estimated quickly.
- Head and neck — 9%
- Each upper extremity — 9% (total 18%)
- Anterior trunk — 18%
- Posterior trunk — 18%
- Each lower extremity — 18% (total 36%)
- Perineum — 1%
Pediatric proportions differ: infants have a relatively larger head (about 18%) and smaller legs (about 14% each), so the Lund-Browder chart is preferred in children when accuracy matters. The PTA does not calculate fluids, but recognizing that a burn covering more than about 20% TBSA represents a major burn helps the candidate anticipate intensive positioning, splinting, and pulmonary care.
Anti-Deformity Positioning
Burned skin and underlying tissue contract into the position of comfort, which is almost always a flexed, adducted posture. Anti-deformity positioning opposes that drift.
| Region | Typical Drift Into Deformity | Anti-Deformity Position |
|---|---|---|
| Anterior neck | Flexion | Slight extension; no pillow under the head |
| Shoulder (axillary burn) | Adduction, internal rotation | Abducted around 90 degrees with slight horizontal flexion |
| Elbow (antecubital burn) | Flexion | Extension in a posterior elbow splint |
| Hand (dorsal burn) | Claw deformity (MCP extension, IP flexion) | Intrinsic-plus: wrist 20-30 degrees extension, MCPs 60-70 degrees flexion, IPs extended, thumb abducted |
| Hip | Flexion, external rotation, abduction | Extension and neutral rotation; legs slightly adducted |
| Knee | Flexion | Extension in a knee immobilizer |
| Ankle | Plantarflexion (foot drop) | Neutral dorsiflexion in a foot-drop splint |
Phases And PTA Role
- Emergent or acute phase — Focus is on airway, fluid resuscitation, and positioning. The PTA implements positioning, gentle active range of motion as ordered, and pulmonary hygiene.
- Intermediate or wound-care phase — Daily ranging, ambulation when permitted post-graft, and progression of activity. Grafts are usually protected from shear and motion for about 5 to 7 days post-application before active ranging resumes; follow the surgeon's and PT's written orders.
- Rehabilitation phase — Strengthening, scar management, return-to-function activities, and patient education.
Compression Garments And Scar Management
Custom compression garments are typically fitted once wounds are essentially closed and worn 23 hours per day for 12 to 24 months to flatten hypertrophic scars. Garments are removed only for bathing, skin checks, and laundering. The PTA reinforces wear schedules, inspects skin under the garment, and reports breakdown, drainage, or fit problems to the supervising PT.
An adult sustained burns to the entire anterior trunk and the entire right upper extremity. Using the Rule of 9s, what is the approximate Total Body Surface Area involved?
A patient with deep partial-thickness burns to the bilateral axillae and antecubital regions is positioned in bed by the nursing team with both arms adducted at the sides and elbows flexed for comfort. The PTA recognizes this is contrary to anti-deformity goals. Which positioning correction is most appropriate?