Fusion

Definition

Spontaneous osteonecrosis of the navicular

Results 

90% fusion rates

Lose70% sagittal plane ROM

Disadvantages of Arthrodesis 

Non union rates up to 12%

Decreased gait speed

Poor mobility over uneven surfaces

Biomechanics

Able to achieve relatively high level of function after STJ fusion

- previously believed that isolated STJ fusion should not be performed

- believed that triple arthrodesis was operation of choice for hindfoot

- STJ fusion has superior result with less stress on AJ

Average loss of DF 30% / PF 10%

Position of hindfoot determines flexibility of transverse tarsal (CCJ & TNJ) joints

- imperative that fusion be positioned in ~ 5^o valgus 

Conditions

1.  PIPJ Synovitis

- synovectomy via dorsomedial approach

2.  Flexor tenosynovitis

- may cause trigger finger

- trial HCLA

- remove synovits but don't release A1 pulley

- will worsen ulna drift

3.  DIPJ

- rarely affects

Epidemiology

Extremely common

- 90% by 10 years have wrist problems

Principles

Landsmeer 1961

- treat wrist at same time as treat fingers or will recur

Frequently combine procedures

- synovectomy

- tendon transfer

- ulna procedure

Definition 

Failure of fusion of adjacent ossification centers

Epidemiology

Incidence 3%

Bilateral in 60%

Anatomy

4 ossification centers present in acromion

- pre-acromion

- mesoacromion

- metaacromion

- basiacromion

Epidemiology

Male & Females > 60 years

- X-ray evidence of OA

Symptomatic 

- 25% females

- 15% males

Affected joints

Base thumb

PIPJ / Bouchard's nodes

DIPJ / Heberden's nodes

Definition

Congenital fibrous, cartilaginous or bony connection of 2 or more tarsal bones

- due to failure of segmentation

Peroneal Spastic Flat Foot

- tarsal coalition

- tarsal pain

- reduced STJ motion

- rigid pes planus

- peroneal muscle spasm / tightness

Epidemiology

Present in 6% of population

- symptomatic in 1% of population

Bilateral in 50%