2.7 Fracture Rehabilitation & Immobilization Complications
Key Takeaways
- Rehabilitation after fracture balances protection of healing bone against the morbidity of immobilization; staged progression from non-weight-bearing to protected, then full weight-bearing follows fracture stability, fixation method, and biologic healing phases (inflammatory, reparative, remodeling).
- Common immobilization complications include disuse osteopenia, joint contracture, muscle atrophy, deep vein thrombosis, heterotopic ossification, and pressure injuries; early mobilization and judicious loading mitigate these.
- Cast/wedge correction and surgical fixation (ORIF, intramedullary nail, external fixation) dictate weight-bearing timing: intramedullary nails often permit early weight-bearing, while articular fractures require delayed protected loading.
- Red flags during fracture rehab include compartment syndrome (pain out of proportion, paresthesias, pallor), implant failure, and infection; a drop in pain followed by recurrence suggests refracture or hardware complication.
Fracture Rehabilitation & Immobilization Complications
Fracture care is a shared Domain D topic spanning orthopedic surgery and physiatry. The rehabilitation physician must understand fracture healing biology, fixation stability, and the systemic/musculoskeletal consequences of immobilization to design safe, progressive loading programs.
Fracture Healing Phases
| Phase | Time Frame | Biological Events | Rehab Implication |
|---|---|---|---|
| Inflammatory | 0-7 days | Hematoma, granulation, inflammatory cells | Splint/immobilize; control edema/pain; DVT prophylaxis. |
| Reparative | ~1-6 weeks | Soft then hard callus (woven bone) | Begin protected ROM/AAROM adjacent joints; isometrics. |
| Remodeling | Weeks-months-years | Lamellar bone replacement, medullary canal restoration | Progressive weight-bearing, strengthening, return to function. |
Fixation-Specific Weight-Bearing Progression
Undisplaced/Stable Cast ──► Delayed Weight-Bearing Until Callus
Intramedullary Nail ──► Early Weight-Bearing (Load-Sharing Device)
Plate/Screw (ORIF) ──► Variable; Depends on Comminution & Bone Quality
External Fixator ──► Protected; Pin-Site Care Paramount
Articular (ORIF Joint) ──► Delayed, Protected Loading to Preserve Cartilage
Intramedullary nails are load-sharing devices that frequently permit early, even immediate, weight-bearing in long-bone shaft fractures. Articular fractures (tibial plateau, acetabulum, pilon) require delayed, protected weight-bearing to allow subchondral bone and cartilage recovery. Periarticular locking-plate constructs depend on fracture comminution and bone quality.
Immobilization Complications
- Disuse osteopenia and muscle atrophy: Rapid within weeks; mitigate with isometrics of immobilized muscles, electrical stimulation, and early mobilization of adjacent joints.
- Joint contracture: Prolonged immobilization shortens capsule and ligaments; prevent with early AAROM/ROM of uninvolved joints and guarded ROM of the fracture site once stable.
- Deep vein thrombosis: Lower-extremity fractures and immobility confer high VTE risk; chemoprophylaxis (LMWH, apixaban) per Caprini/trauma protocol.
- Heterotopic ossification: Particularly after elbow fracture, SCI, or TBI; presents with pain, decreased ROM, erythema; prophylaxis (indomethacin for elbow, radiation) and early ROM.
- Pressure injuries and cast complications: Padding, skin checks, and prompt cast windowing for localized pain prevent skin breakdown.
- Reflex sympathetic dystrophy / CRPS: See chronic pain chapter; early protected motion and desensitization help.
Red Flags & Compartment Syndrome
Compartment syndrome is a surgical emergency. The classic "5 Ps"—pain out of proportion to injury, paresthesias, pallor, pulselessness (late), and paralysis—are unreliable in sequence; pain out of proportion and pain with passive stretch are the earliest. Increased analgesic requirement is a sentinel sign. Compartment pressure measurement (> 30 mmHg or within 30 mmHg of diastolic) confirms; urgent fasciotomy prevents Volkmann ischemic contracture.
Pediatric & Special Considerations
Children's fractures remodel well due to thick periosteum; Salter-Harris classifications guide management (Type II most common; Type IV intra-articular, prone to growth arrest; Type V compression, occult). Greenstick and torus (buckle) fractures are incomplete and stable. Pathologic fractures from osteogenesis imperfecta, malignancy, or metabolic bone disease require etiologic workup.
Pediatric Fracture Considerations
Children's fractures remodel well due to a thick, osteogenic periosteum and growth potential. Salter-Harris classification guides management and prognosis:
| Type | Description | Significance |
|---|---|---|
| I | Physis separation | Good prognosis; often occult clinically |
| II | Through metaphysis | Most common; generally good prognosis |
| III | Through epiphysis (intra-articular) | Requires anatomic reduction; growth-plate related |
| IV | Through epiphysis, physis, metaphysis (intra-articular) | High growth-arrest risk; needs ORIF |
| V | Physis compression | Occult; growth arrest common |
Greenstick (incomplete, one cortex) and torus/buckle (compression, no displacement) fractures are incomplete, stable, and managed briefly. Remodeling is greatest in fractures near the physis, in the plane of joint motion, and in younger children; angulation outside the plane of motion or rotational malalignment remodels poorly and requires reduction.
Pathologic Fractures & Bone Health Workup
A fracture from minimal trauma, or a fracture in an atypical location, prompts evaluation for pathologic causes: metastatic disease (breast, prostate, lung, thyroid, kidney, myeloma), primary bone tumor (osteosarcoma, Ewing), osteogenesis imperfecta, metabolic bone disease, or chronic steroid/immobility bone loss. Imaging (lytic/sclerotic lesions, MRI for marrow involvement), labs (calcium, SPEP/UPEP, PSA, TSH, vitamin D), and biopsy when indicated establish etiology. The physiatrist should suspect pathologic fracture when pain precedes trauma or when imaging shows an aggressive lesion.
DVT Prophylaxis & VTE Risk in Fracture Patients
Lower-extremity fracture and immobility confer high venous thromboembolism risk. Risk stratification (e.g., Caprini score, Rogers score for trauma) guides prophylaxis: pharmacologic (LMWH, apixaban) plus mechanical (intermittent pneumatic compression) when not contraindicated. Pelvis/acetabulum, hip, and multiple long-bone fractures are highest risk. Balancing fracture bleeding against VTE risk, prophylaxis is typically initiated within 24-72 hours once hemostasis is secure.
Functional Outcome Priorities
Rehabilitation after fracture targets restoration of range of motion, strength, gait/balance, and return to work/sport. Outcome measures (e.g., DASH/QuickDASH for upper extremity, LEFS, KOOS/HOOS for lower extremity) quantify function. The physiatrist sets weight-bearing progression, monitors for complications, coordinates therapy, and times return to sport/work based on radiographic and clinical healing rather than a fixed calendar.
A patient with a midshaft tibial shaft fracture treated with an intramedullary nail asks when walking may begin. What is the most accurate guidance?
Six weeks after an elbow fracture, a patient develops increasing pain, warmth, and loss of elbow extension despite immobilization. What complication is most likely developing?
A patient in a below-knee cast for an ankle fracture develops increasing pain requiring escalating opioids and pain on passive toe extension at 18 hours. What is the priority action?