Define Complications of Plaster Cast. Describe its complications and prevention.
Overview
The plaster (or synthetic) cast is a mainstay of conservative fracture treatment, but it has important complications, some of which are limb-threatening. Anticipating and recognising them is essential.
Key Complications
A cast that is too tight (or applied to a swelling limb) can cause compartment syndrome and neurovascular compromise — the most dangerous complication. Pressure sores develop over bony prominences from poor moulding or ridges. Nerve palsy can occur from local pressure (e.g. The common peroneal nerve at the fibular neck). Prolonged immobilisation causes ‘cast/fracture disease’ — joint stiffness, muscle wasting and disuse osteoporosis. Other problems include a loose/ineffective cast (allowing fracture displacement), skin maceration/allergy, and thermal injury during setting.
DANGER / REMEMBER
Warn every patient in a cast about the danger signs of a tight cast: increasing pain, tingling/numbness, swelling, or colour change of the fingers/toes. The response is to split or remove the cast immediately and reassess — never to reassure and wait, as delay risks compartment syndrome and ischaemic contracture.
Prevention
Complications are minimised by applying a well-moulded, well-padded cast, using a backslab or split cast for a fresh, potentially swelling injury, elevating the limb, giving clear cast-care instructions, and reviewing the patient to check the cast and neurovascular status.
Clinical Note
The single most important message about casts is that a limb in a fresh cast can develop a compartment syndrome, and the earliest and most reliable warning is pain out of proportion, made worse by passive stretch of the fingers or toes; the correct response is to split the cast and its padding down to skin at once. Regular review, elevation and clear written cast-care advice prevent most other complications.
CLINICAL PEARL
The rule that saves limbs: pain out of proportion, worse on passively stretching the toes/fingers, in a casted limb means compartment syndrome until proven otherwise — split the cast to skin at once, do not reassure and wait.
Increasing pain under a cast means split it, do not sedate.
KEY POINT
Key points TO remember
- Cast complications range from nuisance to limb-threatening.
- Most dangerous: tight cast → compartment syndrome / neurovascular compromise.
- Also: pressure sores, nerve palsy, cast disease (stiffness, wasting, osteoporosis), loose cast.
- Warn of tight-cast danger signs (pain, numbness, swelling, colour change) → split cast at once.
EXAM TIP
Sources: Maheshwari's Essential Orthopaedics; Apley & Solomon's System of Orthopaedics and Trauma; AO Principles of Fracture Management.
P a R T III
Anaesthesia
Chapters 28–39 · 144 questions
All questions in Miscellaneous & Rehabilitation
- Q1Prosthetics, Orthotics & Rehabilitation ★
- Q2Describe Gait — Normal Cycle & Pathological Gaits in detail. ★
- Q3Describe Bone Grafting & Bone Substitutes in detail. ★
- Q4Describe Knee Ligament & Meniscal Injuries in detail. ★
- Q5Define Traction & Immobilisation. Describe its types and complications. ★
- SN1Define Tennis Elbow & Golfer’s Elbow. Describe its clinical features and management. ★
- SN2Write a short note on Rotator Cuff Injury & Impingement. ★
- SN3Define Plantar Fasciitis. Describe its clinical features and management.
- SN4Define De Quervain’s Tenosynovitis. Describe its clinical features and management.
- SN5Write a short note on Clinical Tests for Knee Injuries. ★
- SN6Define Ganglion. Describe its clinical features and management.
- SN7Define Complications of Plaster Cast. Describe its complications and prevention. ★