12.3 Musculoskeletal Assessment, Traction, Cast Care & Mobility Promotion
Key Takeaways
- Neurovascular evaluation must assess the 6 Ps: Pain, Paresthesia, Pallor, Paralysis, Pulselessness, and Poikilothermia (coolness).
- Acute Compartment Syndrome is a surgical emergency featuring pain out of proportion to injury and pain on passive stretch; elevation >30 mmHg requires immediate emergency fasciotomy.
- Skeletal traction weights must hang freely suspended at all times without touching the floor or bed frame; pin site care requires strict aseptic technique.
- Plaster of Paris casts require 24 to 72 hours to dry completely and must be handled only with the palms of the hands to prevent pressure point indentation ulcers.
- Post-operative posterior total hip arthroplasty precautions require avoiding hip flexion >90 degrees, hip adduction across midline, and internal rotation to prevent prosthesis dislocation.
12.3 Musculoskeletal Assessment, Traction, Cast Care & Mobility Promotion
Musculoskeletal nursing encompasses orthopedic trauma, fracture immobilization, traction management, cast maintenance, and post-operative mobility promotion. In Singapore acute and community hospitals—such as Tan Tock Seng Hospital (TTSH), Singapore General Hospital (SGH), and Jurong Community Hospital (JCH)—registered nurses play a pivotal role in preserving neurovascular integrity, preventing catastrophic complications like Acute Compartment Syndrome, and supporting safe rehabilitation.
1. Comprehensive Musculoskeletal Assessment & The 6 Ps
Neurovascular compromise can occur rapidly following limb trauma, orthopedic surgery, or tight cast application. The nurse must perform structured Neurovascular Assessments (NV checks) distal to the injury site every 1 to 2 hours during the first 24 hours.
The 6 Ps of Neurovascular Assessment
- Pain: Uncontrolled, severe pain out of proportion to the physical injury, or increased pain during passive muscle stretching (the earliest and most sensitive sign of ischemia).
- Paresthesia: Pins-and-needles sensation, numbness, or altered cutaneous sensation (indicates nerve compression).
- Pallor: Pale, dusky, or mottled skin color; capillary refill delayed >2 seconds (indicates arterial insufficiency).
- Paralysis: Loss of voluntary motor function or muscle weakness distal to the injury (indicates advanced nerve damage).
- Pulselessness: Diminished or absent distal peripheral pulses (e.g., dorsalis pedis, posterior tibial, radial pulses; evaluated via Doppler ultrasound if non-palpable).
- Poikilothermia: Coolness or coldness of the affected limb compared to the contralateral warm extremity.
2. Acute Compartment Syndrome (ACS): Surgical Emergency
Acute Compartment Syndrome (ACS) occurs when elevated tissue pressure within a closed, non-yielding fascial compartment compromises capillary blood flow, leading to cellular hypoxia, muscle necrosis, and irreversible nerve damage within 4 to 6 hours.
Pathophysiology & Causes
- Decreased Compartment Size: Tight casts, restrictive dressings, or excessive wound closure.
- Increased Compartment Contents: Edema from burn injuries, severe crush trauma, arterial bleeding, or fracture hemorrhage.
Critical Nursing Actions for Suspected ACS
- Immediate Surgeon Notification: ACS is a surgical emergency. Notify the orthopedic surgeon immediately.
- Positioning at Heart Level: Do NOT elevate the limb above heart level (elevating decreases arterial perfusion pressure). Do NOT apply ice (causes vasoconstriction).
- Remove Restrictive Material: Bivalve (cut) the cast or loosen tight pressure bandages immediately to relieve external pressure.
- Emergency Fasciotomy Preparation: Prepare patient for urgent surgical fasciotomy (incising the non-yielding fascia to decompress the compartment). Intracompartmental pressure >30 mmHg mandates surgical intervention.
3. Traction Systems & Pin Site Aseptic Care
Traction applies a pulling force to an injured body part or extremity to maintain functional alignment, reduce fracture dislocations, relieve severe muscle spasms, and immobilize joints.
Skin Traction vs. Skeletal Traction
| Parameter | Skin Traction (e.g., Buck's Traction) | Skeletal Traction (e.g., Thomas Splint / Steinmann Pin) |
|---|---|---|
| Mechanism | Pulling force applied directly to skin via foam boots, straps, or adhesive tape | Pulling force applied directly to bone via metal pins, wires, or tongs (Kirschner wire, Steinmann pin) |
| Weight Limit | Lightweight: 2.0 to 3.5 kg (5 to 8 lbs) | Heavyweight: 7.0 to 12.0 kg (15 to 25 lbs) |
| Primary Indication | Temporary pre-operative stabilization for hip/femur fractures to relieve muscle spasms | Long-term fracture alignment and immobilization of complex femoral or tibial fractures |
| Infection Risk | Low risk (skin breakdown, friction blisters under boot) | High risk (pin site osteomyelitis, deep bone infection) |
Principles of Traction Nursing Care
- Weights Hang Freely: Weights must hang freely suspended in the air at all times. They must NEVER rest on the floor, bed frame, or footboard.
- Line of Pull: Maintain straight alignment of ropes along the central line of pull through pulley grooves. Ensure ropes are unfrayed and knots are tight and secure.
- No Removal Without Order: Never remove skeletal traction weights without a explicit written medical order, except in life-threatening emergencies during CPR.
- Counter-Traction: Ensure patient's body position acts as counter-traction (elevate foot of bed for lower extremity traction) to prevent patient from sliding down.
Pin Site Care Protocol
Pin site infection can progress to osteomyelitis. According to MOH clinical guidelines:
- Perform pin site care daily using strict aseptic technique.
- Cleanse pin-skin interface using sterile 0.9% Normal Saline or 0.05% Chlorhexidine gluconate per hospital policy, wiping radially away from the pin outward.
- Crusts at the pin site should be left intact if adhering, or gently cleansed as per protocol; monitor for purulent discharge, surrounding erythema, skin tenting, or pin loosening.
4. Cast Care & Handling Guidelines
Casts provide rigid external immobilization for fractures and joint deformities.
Plaster of Paris vs. Synthetic (Fiberglass) Casts
- Plaster of Paris (Gypsum): Requires 24 to 72 hours to dry completely. Heavy, non-water-resistant. Exothermic reaction (gives off heat while setting).
- Fiberglass (Synthetic): Dries completely in 20 to 30 minutes. Lightweight, water-resistant, durable.
Handling Wet Plaster Casts
- Palming Technique: When moving or supporting a wet plaster cast, handle it ONLY with the flat palms of open hands, never with fingertips. Fingertip pressure creates localized indentations inside the cast wall, causing pressure ulcers and tissue necrosis.
- Drying Care: Turn patient every 2 hours to allow uniform air exposure. Keep cast uncovered; do not use heavy blankets or artificial heat dryers.
- Elevate Limb: Elevate casted limb on pillows above heart level for the first 24 to 48 hours to minimize post-injury edema.
Patient Education & Complication Warnings
- Never insert objects (knitting needles, rulers) inside the cast to scratch itchy skin (breaks skin barrier leading to cellulitis). Advise cool air blowing from a hairdryer instead.
- Report immediate warning signs: foul odor (indicates tissue necrosis/infection beneath cast), "hot spots" over bony prominences, persistent numbness, or cold digits.
5. Post-Operative Orthopedic Mobility & Safety Precautions
Total Hip Arthroplasty (THA) Precautions (Posterior Approach)
To prevent joint prosthesis dislocation following posterior-approach hip replacement, instruct patient for 6 to 12 weeks:
- Avoid Hip Flexion >90 Degrees: Do not bend forward at the waist past 90°, do not sit in low chairs, and do not pick objects off the floor.
- Avoid Hip Adduction: Do not cross legs or ankles across midline. Use an abduction pillow between legs while lying in bed.
- Avoid Internal Rotation: Do not turn toes inward when standing or pivoting.
Total Knee Arthroplasty (TKA) Care
- Encourage early weight-bearing ambulation with physical therapy assistance.
- Utilize Continuous Passive Motion (CPM) devices as prescribed to enhance knee flexion range of motion.
- Elevate leg when resting, but avoid placing pillows directly under the knee joint (prevents flexion contractures).
Fall Prevention Bundle (MOH Hospital Standard)
Orthopedic patients are at high fall risk. Implement the mandatory fall prevention bundle:
- Assess fall risk daily using Morse Fall Scale or Hendrich II Model.
- Apply yellow color-coded fall risk wristband and signage over bed.
- Keep bed in lowest position with brakes locked; call bell within reach; non-slip socks on patient feet.
A patient who underwent open reduction and internal fixation (ORIF) of the tibia 6 hours ago reports severe, unremitting leg pain that increases sharply upon passive stretch of the toes. Distal pulses are weak. What is the nurse's immediate action?
A nurse is caring for a patient in skeletal traction for a femur fracture. Which observation indicates a breach of correct traction setup that requires immediate corrective action?
Which movement must a patient avoid following a total hip replacement (posterior approach) to prevent joint prosthesis dislocation?