week 4 Fractures and Bone Healing

These flashcards include key terminology and definitions related to fractures and bone healing, based on the provided lecture notes.

Wolff's Law

Bones become thicker and stronger over time to resist forces upon them, and thinner and weaker if there are no forces to act against.

Dye's Envelope of Function

Refers to the balance of mechanical loading on bones where underloading (sub-physiological loading) leads to weakness and atrophy while overloading (supraphysiological) loading leads to injury. Zone of homeostasis = maintenance

Avulsion Fracture

A fracture where a piece of bone is pulled off by a tendon or ligament, often due to sudden muscle contraction.

Cause of fracture

In/direct trauma, pathological causes, fragility/insufficiency #, stress #, avulsion #

Tendinous avulsion #

Common in F 13-14yo, or M 17-18, commonly occurring in LL. Pelvis area and areas with muscle capable of explosive force

Ligamentous avulsion #

Most common in knee, ankle, wrist, mainly in adults

Management of avulsion #

Confirm diagnosis and establish degree of avulsion with imaging (xray), Attain orthopaedic consultation for significant cases that may require surgical intervention, Period of NWB/reduced WB/immobilisation, Pain management via medication, Gradually restore ROM, Regain strength and stability, Sport specific rehab

Pathological #

Occur in abnormal bone, ie weakened by disease (tumour or metabolic), by trauma or spontaneously by minor forces that would normally be sufficient to #.

Pathological # aetiology

Commonly seen proximal humerus, femur shaft, ribs, vertebrae body, # may not unite, and therefore management determined by specialist collaboration

Fragile/insufficient #

Considered stress fracture within fragile bone, may result in normal level of bone stress (walking/standing). Broader term used to describe weakened bone breaking following minimal trauma

Underlying causes of fragility/insufficient #

OP, ,Rheumatoid arthritis, long term steroid use, radiation therapy, metabolic disease

Common areas of insufficient #

Pelvis, tibia, feet

Treatment insufficient # dependent on

Location/degree of #

Long term treatment insufficient #

Incorporate WB exercises to target bone density

Stress #

Microscopic # resulted from repeated biomechanical stress, commonly occurring in WB bone (vertebrae, tib/fib, pelvis). Overuse injury caused by increase in activity frequency or intensity or both. Bone stress reaction, normally diagnoses via MRI

Stress # management

Stop aggravating activity (relative rest), offloading bon- crutches, walking boot, use pain to guide degree of offloading. Maintain fitness through lower body bearing activities, use patient education and address modifiable risk factors. Treat the individual, as other professionals may be required

#1 tibial plateau

Split fracture of lateral of tibial plateau

#2 tibial plateau

Split depression of lateral tibial plateau

#3 tibial plateau

Central depression of lateral plateau

#4 tibial plateau

Split of medial tibial plateau

#5 of tibial plateau

Bicondylar tibial plateau fracture

#4 of tibial plateau

Dissociation between metaphysis and diaphysis

Skin / skin tissue trauma (language of #)

Open or compound (out of skin), closed or simple (in skin)

Stable #

No reduction required, bone ends held in place by surrounding tissue, minimal support required

Unstable #

Can displace post reduction due to location, shape, cause. Soft tissue damage occurs, and there is personal/environmental contextual factors

Shape / type of fracture

Transverse/horizontal, oblique/spiral, crush, comminated, greenstick/incomplete

Transverse #

Horizontal fracture line, usually sustained from direct trauma that is perpendicular

Impacted #

Compressive force- bone driving into another piece of bone, resulting in significant trauma in adults- paeds bone is softer, so can occur easier

Spiral #

Fracture line spirals/twists down bone, caused by rotational force to bone

Comminuted #

Bone broken into several pieces (3+), result of significant /high trauma

Greenstick #

Incomplete fracture, one side of bone is #, other is bent, common in paeds due to softer bone

Oblique #

Angled/diagonal fracture line, usually resulting from direct angular trauma to bone

Displacement status

Displaced, undisplaced, impacted

Displacement - displaced #

Bone ends dont meet, reduction is required to ensure good anatomical alignment

Displacement- undisplaced #

Bone ends in apposition, no need or reduction but requires support (brace/cast)

Displacement - impacted

Bone ends compress together, stable but shortened bone, often external support required, required dec WB in LL #

Articualar injury and considerations

Intraarticular #- cross joints surface, often from blunt force trauma / MVA, articular cartilage usually damaged, may impede healing time and mangement, linked with post traumatic arthritis

Subluxaition

Joint surface displacement without fracture, partial dislocation which relocates spontaneously, results in stretching of lig, soft injury tissue injury- can result in long term joint instability if not managed

Dislocation

Joint surface displacement without fracture- total malalignment of joint and severe stretching of ligaments. Soft tissue injury that can result in long term joint instability if not managed

Fracture-dislocation

Dislocation associated with fracture, first reduce joint displacement then manage fracture, Eg Sachs Lesion compression fracture with head of humerus

Common fracture in UL

Colles #- wrist, Smiths #- wrist, Boxer’s #- 5th metacarpal, Monteggia fracture - dislocation - unla, Hills Sachs fracture/lesion- head of humeus

Common # in LL

Potts- bimalleolar # ankle, Pilon #- distal tib, Jones#- 5th metatarsal, LisFranc- tasometatarsal joint fracture/dislocation, Maisonneuve #- prox fib

Clinical # assessment

High or low mechanism of injury, was there audible noise, swelling, weight bearing ability, pain patter (delayed/immediate), PMedHX - factors inc risk, healing time, or previous # history

Objective # assessment

Deformity present, swelling/bruising present, abnormal movement present, bony crepitus present, pain on palpation

Imagine # assessment

XRAY, MRI, CT

Xray

Majority of fractures and dislocations detectable

Computerised tomography (CT)

Detects spinal fracture and dislocation

MRI

Displays soft tissue and neuro structures, less radiation then CT, good for Pt with multiple injuries

Conservative management

Non invasive/non surgical management, often for paediatrics/elderly. Indications include medial contraindications, inadequate bone quality, closed, undisplaced fractures

Surgical management

Sample indication- non union/ malalusions that have failed to respond to nonoperative management. # is open/unstable/displaced/intraarticular/complex/pathological, ones known to heal poorly, significant avulsion #, or those that would poorly tolerate prolonged immobilisation

Principles of # management

Reduction, immobilisation, Preservation of function

#reduction

Indicated in fractures requiring realignment of bone fragments

Types of reduction

Closed reduction - closed manipularion/mechanical traction, open reduction

Closed reduction

Usually done in sedation, fragments grasped via soft tissue and manually manipulated to acceptable position

Mechanical traction (closed reduction)

Formally use for femoral shaft fracture and cervical spine fracture, tracture applied by MDT member with specialist using weights or by screw device

Open reduction

Indications - acceptable reduction cannot be obtained/maintained conservatively, when joint surfaces are involved, when there is nerve/artery damage, once reduced, fragments fixed internally (ORIF)

Immbolisation aims

Prevent further displacement, relieve pain, prevent movement that may interfere with bone unionI

Immobilisation considersation

Cause of fracture, classification (soft tissue damage, shape/line, displacement), position/site of #, stability, swelling, healing stage, comorbidities, medication, personal/environmental factors, access

Non surgical immobilsation

Cast, splint/brace, skeletal traction

Surgical immobilisation - open reduced internal fixation (ORIF)

Provides immediate stability that may facilitate earlier mobilisation. Used when open reduction has been necessary, or there is failure to maintain # reduction by conservative means

Surgical immobilisation - external fixation

Anchorage of bone fragments to an external devices such as a metal bar (fixator) using pins inserting into proximal and distal fragments of long bone fracture, System allows for adjustment of fragment ends, Routinely used to manage unstable, open or infected fractures that occur with poly trauma, Can be used as alternative to internal fixation to manage closed fractures of long bone

Types of surgical external immbolisation fixation

Circular (Illizarov), Linear (Hoffman Fixator / Ex-Fix)

Other surgical immobolisation

Intramedullary (IM) nailing, Locking plates and screws

Signs POP cast may be too tight

Vascular, neurological, pain

Vascular sign on POP cast tightness

Distal swelling that doesnt reduce on elevation, distal segments feel cold and clammy, distal skin appears blue/purple, objective Ax- capillary refill

Neurological sign on POP cast tightness

Paraesthetia / anaesthesia in sensory field of compressed nerve, objective Ax- periperal sensory/ motor testing

Pain sign on POP cast tightness

Due to vascular or neural compression, pins/needles, sharp/ shooting desciptions

Immobilisation - preservation of function

Depends on - cause of #, # classification - soft tissue, shape/line, displacement (stability), position/site of #, type of immobilisation, stage of healing, comorbidities/medication, personal/environmental factors, access to rehab/care

Bone healing- primary (direct)

Bone ends in apposition and rigidly fixed/compression so there is no movement, no callus formation, osteoclasts- cross fracture, osteoblasts - lay down new bone

Bone healing - secondary (indirect)

Motion minimalised by internal or external fixation, some motion present, haematoma, fibrocartilaginous callus, bony callus, remodelling

Stages of bone healing

Acute, union, consolidation

Bone healing stage Acute

Includes haematoma and proliferation stages, # site visible on Xray, may be stable or unstable

Bone healing stage Union

Soft callus develops into hard callus, minimal movement at bone ends, bones will move a little under pressure and be painful, full bone maturity, # line visible on Xray

Bone healing stage Consideration

Full repair of bone, no movement evident at # site under pressure, trabeculae cross over previous # site, no # line on Xray, original strength achieved

Management through stages - acute

Reduction, immobilisation, often NWB in LL #

Management through stages - union

Can usually start to load #- loading assists healing, still requires support during WB, gentle exercises can often be initated

Management through stages - consolidation

Commence full function, usually WBAT/FWB, immobilisation removed, can start resistance work across # site

Confirming bone healing

Radiology evaluation / comparison, historical expectations- average time of healing for location / type of #, clinical review - no mobility between fragments, no tenderness on firm palpation over # site, no pain on loading or application of stress

Approximate healing times

Paeds healing ½ of adult, LL takes longer then UL, consolidation takes 2x of union, distal sites often take longer then proximal, simple # generally heal faster then complex, hand and wrist # heal quick 4-6/52, long bone # take 12/52+, bone with poor supply (tib/scaphoid) takes longer

UL healing time

Phalange 3/52, metacarpal 4-6/52, distal radius 4-6/52, humerus 6-8/52, lower arm 8-10/52

LL healing time

Metatarsal 6+/52, tibial 10/52, femoral neck 12/52, femoral shaft 12/52

Early management of trauma Pt

Multisystem management and assess, Provide splint and brace as appropriate, Review and provide education regarding weight bearing / post operative restrictions, Provide strategies for pain and swelling management, Educate on safe and suitable bed mobility and transfers, Provide appropriate gait aid and gait pattern corresponding to WB status and patient capacity, Provide step/stair training if patient will need to navigate it, Provide safe and suitable exercise program, Educate on importance of exercise for preservation of function and recovery, Educate staff/family on patients assistance or safety requirement, Coordinate plain for ongoing rehabilitation

Post op general care

Pain and swelling management, cardiorespiratory management

Post op general care - pain and swelling management

Elevation, compression, education- pain meds and timing, gentle movement, cyrotherapy

Post op general care - cardiorespiratory management

Encourage deep breathing and upright sitting, ensure effective cough/huff, teach ankle pumps for circulation

Post op rehab

Bed mobility, transfers, gait training

Post op rehab- bed mobility

Moving up and down and side to side in bed, rolling, supine - sitting

Post op rehab- transfers

Sit to stand, bed to chair

Post op rehab- gait training

Adhere to post op WB status, provide walking aid to increase stability and reduce load, teaching safe and effective gait pattern

Post op MSK management

Stable #, unstable #

Stables #

Preserve joint movement proximal and distal to # that are not immobilised, safety restore affected mobility as advised by orthopaedics, no exercises with additional load until union

Unstable #- Differences in overall management

Often have extended period of immobilisation, usually NWB status until evidence of sufficient callus formation, initially priority is protect # site, and present additional complications, physio referral may be delayed

Unstable #- physio mods

Avoid contraction of muscles that stress # site, may need modified approach to regain function - NWB exercise, gravity eliminated movement and gentle isometrics, passive ROM. Provide additional hands on support for fracture with bed mobility and transfers. NWB gait education- elderly may been gutter/pulpit frame to lead through UL

#complications- intrinsic

Delayed union, malunion, nonunion, avascular necrosis, shortening of bone length, post traumatic osteoarthritis, tendon freying

#complications - extrinsic

Vascular, nerve or soft tissue injury, joint stiffness, muscle weakness (disuse atrophy, direct muscle damage), deep vein thrombrosis (clot), fat embolism, compartment syndrome, infection (osteomyelitis)

Avascular necrosis (AVN)

Bone death due to deficient blood supply, common site- scaphoid fracture, talus, proximal femur fracture, Navicular Kohlers disease), Lunate (Kienbocks disease). Pt presents pain long after natural time of healing for that #

Bone malunion

Bone heals in suboptimal position

Bone nonunion

Bone has not aligned / failed to heal at all

Influences of bone mal/non union

Blood supply, stability, age, infection or comorbidities, lifestyle, nutrition and medication

Influences of bone mal/non union- blood supply

Bone supply and location, degree to traumatic disruption, underlying vascular issues, significant swelling/soft tissue damage can reduce BF