ABx-loaded product-from Injury

Prophylaxis and treatment of implant-related infections by local application of antibiotics
Injury 2006

Basic concepts for Implant associated infection
．Bacteria on implant: decreased metabolic activity
．Higher MIC was needed to eradicate organism when metabolic activity was decreased (Pseudomonas aeruginosa 800X if reduced metabolic activity)
．Local application, like ABx impregnated spacer, could achieve 1000x concentration or higher

These article
Prophylaxis：Cement bead, Antibacterial coating implant
Treatment：Cement bead, GM-loaded collagen sheet, ABx-loaded spacer

Initially
．GM loaded cement beads
．higher local concentration, no systemic effect, gradual release
．disadvantage: select GM resistant bacteria
．should be removed 4-6 weeks later (became foreign body)

ABx-coating implant
．Synthes
．biodegradable GM, Chlorohexidine
．reduce the rate of osteomyelitis
．pending large, clinical trials

ABx loaded collagen sheet
．PMMA beads: another operation for removal
．Collagen sheet: biodegradable
．disadvantage: short T1/2

ABx loaded spacer
．prevent soft tissue contracture, arthrofibrosis, instability
．disadvantage: expensive

subtrochanteric osteotomy for Crowe IV dysplatic hip

subtrochanteric osteotomy for Crowe IV dysplatic hip - JBJS Am 2009/09

Dysplastic hip: Crowe classification, according to its degree of subluxation (dislocation)

Crowe type IV: complete dislocation

True acetabulum: Better quality for Cup support
Without shortening: difficult reduction, sciatic nerve injury

THA with subtrochanteric shortening osteotomy:
．for cementless proximal ingrowth stem
．avoid change of anatomy of proximal femur

Surgical technique
．osteotomy site: 8 – 10 cm distal to tip of greater trochanter
．transverse subtrochanteric osteotomy
．autogenous cancellous bone graft over osteotomy site
．neck cut region: 1 cm proximal to lesser trochanter

Preparation of femoral canal
．reaming + broaching
．osteotomy
．implantation of stem
．lateral coverage for cup: superolateral femoral head
．osteotomized femoral canal: as cortical strut graft, fixed with Cable wire

middle phalanx-Rockwood

Transverse fracture: more stable, less shortening risk, no periosteal envelope stripping

Extension block splinting:
．for base fracture
．for p2 base, intraarticular involvement < 40 degree
．initial 60 degree flexion, then deduct 10 degree/ week
．maintain congruent reduction

Condylar fx of the head
．close: 2 k-wire, 1 transverse, 1 oblique
．open: consider lag screw

Unstable shaft fracture
．1.2 mm K-wire
．cross pinning at fracture site: highly unstable
．interfragmentary lag screw
．mini-plate

Partial articular base fracture
．extension block pinning

Author preferred treatment
．shaft: splinting for stable, crossed pinning for unstable
．dorsal base: extensive block pinning 3 weeks. ORIF with 1.3 mm lag screw for delayed treatment

approach to spinal trauma

Approach to spinal trauma patient

Assessment (concomitant injury, neurological deficit,
Concomitant injury
1．Head, chest, long bone injury
2．Chance fx: associated with hollow viscus injury

Neurological deficit
1． ASIA score (American spinal injury association)
2． Clinical assessment

Sacral sparing & spinal shock
Bulbocarvenous reflex: mark of resolution of spinal shock
Penile or urethra stimulation → contracture of anal sphincter


ASIA score
A: complete injury
B: Sensory preserved
C: Motor preserved, MP < 3
D: Motor preserved, MP > 3
E: Normal

Clinical assessment
1． Central Cord syndrome
2． Brown sequard
3． Anterior Cord
4． Conus Medullaris
5． Cauda equina

C-spine imaging
．3 views: AP, LAT, Odontoid
．5 views: 3 views + oblique
．dynamic view: flex-ext view, time consuming in acute stage, muscle spasm masked subtle instability
．unconscious patient: LAT view only

T-L imaging
．plain film, CT, MRI for soft tissue injury
．included abdominal CT scan to exclude intra-abdominal injury

Classification of T-L spine injury
．AO classification, Denis system

Denis system
．3 column theory
．Comperssion, Burst, Seat-belt type, Fx-dislocation

distal phanlanx fracture, Rockwood

Ch. 24 Fx & dislocation of the hand
Fractures in Adults, Rockwood, 6th edition

Trade-off: stiffness or instability (mal or nonunion?)

Mechanism
Axial loading
．associated injury to carpus or upper limb

Others: isolated phalangeal injury
．crushing, trapping injury: associated soft tissue damage

Fracture reduction
．Gentle maneuver instead of forceful traction
．MP joint flexion: decreased flexor tendon force

Finger immobilization: 4 weeks, than active ROM

Local anesthesia
．NO BOSMIN
．add hyanluronic acid: enhance anesthesia, less local edema
．add 1cc 10% Bicarbonate: reduce acidity of lidocaine, less pain on injection

Bone loss in finger fracture
．Open fracture, gunshot injury
．Comminution and bone loss
．Temporary external fixation(固定distal part) or spacer
．Delayed grafting with corticocancellous iliac bone graft (more stable) or
cancellous bone graft

Distal phalanx fracture
．Tuft, Shaft, and base
．base: insertion of extensor & flexor tendon
．relative stable if fracture line distal to tendon insertion

Dorsal base fracture
．avulsion fracture VS shearing fracture
．avulsion: smaller fragment, fracture line perpendicular to tensile force
．shearting: larger fragment, > 20% joint involvement, fracture line perpendicular to joint line

Tuft fracture
．most: splinting
．concomitant of nail bed injury: pinning and repair of nail matrix

Shaft fracture
．pinning in widely displaced fracture, transverse

Dorsal base fracture
．>25% joint involvement: pinning
．extension blocking technique (DIP flexion, 1st pin for extension block of proximal fragment, reduce distal fragment, 2nd pin)
．0.045 inch K-wire
．ORIF：tension band wire, most stable in cadaveric study，but hardware complication was noted in clinical application

pediatric - humeral lateral condylar fracture

Complication after close treatment for lateral conylar or supracondylar
．Supracndylar fx: intact ROM, correctable cubitus varus
．Lateral condylar fx: impaired ROM

Classification of humeral lateral condylar fx

．Pull-off mechanism
．Pull strength from LCL complex

Classification: Milch, Jakob
．Milch I: no through ossification center of capitellum, to trochlea
．Milch II: through ossification center of capitelleum, to capitellum-radio joint

Jakob classification
1.fracture, intact medial cartilage
2.disruption of medial cartilage, minimally displaced
3.rotated and displaced fragment

initial of fracture area: posterolateral cortex

soft tissue over humeral lateral condyle
．LCL complex
．ECRL
．Brachioradialis

X-ray
．Important to differential Jakob stage I & II
．True AP, true LAT, Oblique view

Definition of minimal displacement
．2 mm
．< 2mm, stable, percutaneous pinning
．> 2mm, unstable, ORIF

ORIF:
．Crossed or parallel two pinning
．Kocher's approach

Complications of nonunion
．progressive displacement → cubitus valgus → tardy ulnar nerve palsy

Complications
Biological VS technical

1．Lateral spur formation
Fracture → over dissecting during operation → displaced periosteum → new bone formation

Fishtail deformity
．Premature closure of distal humeral physis
．osteonecrosis

Nerve injury
．acute stage: radial nerve, or posterior interosseous nerve injury
．late stage: tardy ulnar nerve palsy → malunion or nonunion related cubitus valgus. Treated with anterior nerve transposition