risk factors

Postoperative Infection

Incidence

 

Decreasing incidence in recent decades most likely attributable to preoperative antibiotics

 

Ris

 

Conventional discectomy </= 1%

Fusion 2%

Fusion & instrumentation 5-6%

 

Instrumentation doubles infection rate in lumbar fusion

 

Risk factors 

 

Diabetes 

Osteoporosis

Epidemiology

 

1/3 caucasian women > 64

 

Risk Factors

 

Insufficient bone mass at time of skeletal maturity

- peak bone mass is achieved at age 25

 

Rapid loss of bone after menopause

 

Low body weight / weight loss / history of smoking / steroids

 

Primary

 

Type 1

- postmenopausal

- high turnover / osteoclast mediated

- F x 6

Wound Problems

TKR Wound ComplicationIncidence

 

10 -15%

 

Include

- marginal necrosis

- wound slough

- sinus tract formation

- dehiscence

- haematoma

- oozing knee wound

 

Blood supply

 

Anterior knee has no muscles to supply vessels directly 

Management

Incidence

 

Knee > Hip

- superficial position

- limited cover of well vascularised muscle 

- watershed area of skin blood supply anterior to the skin incision 

- much increased in fully constrained prosthesis 

 

Ideal < 1%

 

Risk Factors

 

Increased with

- revision

- prior infection

- RA / Psoriatic arthropathy

- DM

Basic Science

Pathogenesis

 

Virchow's Triad

1. Venous stasis

2. Hypercoagulability

3. Endothelial damage

 

Starts as platelet nidus at valves

- thrombogenic materials elaborated by platelets

- leads to development of fibrin thrombus

- thrombus grows

 

Thrombus may 

- detach as embolus

- be completely dissolved / recanalise

- organise with valve incompetence

Osteogenesis Imperfecta

Incidence

 

Spinal deformities are found in 20% to 80% of patients with OI

 

Risk factors

 

Severe disease with nonambulatory status

 

Progression

 

Scoliosis in OI may progress after skeletal maturity 

- may be related to weakened osteoporotic bone 

 

Management

 

Non operative

 

Bracing

 

Poor results

Lateral Epicondylitis / Tennis Elbow

Incidence

 

Lateral : Medial 9:1

 

Epidemiology

 

4th & 5th decades

- M = F

- 75% dominant arm 

 

50% of regular tennis players

- especially > 2 hrs / week

 

Aetiology

 

Insertion pathology / Enthesopathy

 

Over-extension of the elbow with supination / pronation

 

Anatomy

 

Lateral epicondyle

- anconeus from posterior face

- ECRB and EDC from anterior face (CEO)

Infection

Risk factors

 

Patient 

 

Advanced age

Immunosuppression - steroids / Rheumatoid / DM

Malnutrition - Lymphocyte count / Transferrin / Albumin

Vascular disease

Obesity

Poor skin i.e. psoriasis

Previous infection in joint

Infection elsewhere - i.e. UTi

Prolonged hospital admission

Revision surgery

 

Operative Factors

 

Preoperative

Achilles Tendonopathy

Definition

 

Inflammation of achilles tendon; insertional or noninsertional

 

Spectrum

 

Tendonitis / Tendonosis / Rupture

 

Anatomy

 

Triceps surae

- medial and lateral gastrocnemius

- soleus

- surrounded by paratenon which allows gliding and supplies nutrition

 

Inserts middle 1/3 calcaneal tuberosity

- 2 x 2 cm area

- 90o rotation distally

 

Retrocalcaneal bursa (x2)