Arthritis and Finger Deformities

Osteoarthritis (OA) is characterized by

erosion of articular cartilage and a decrease in the synovial fluid.

Osteoarthritis is also called

Degenerative Joint Disease (DJD)

Osteoarthritis is seen in what joints?

DIP, PIP, and CMC joints of the UE

Rheumatoid Arthritis is characterized by 

progressive, chronic systemic disease in which the immune system attacks the joints

• inflammatory changes of the joints, tendons, and their sheaths

• results in pain, weakness, and dysfunction 

Rheumatoid Arthritis results in 

pain, weakness, and dysfunction 

T or F. Rheumatoid arthritis can affect any joint of the UE.

TRUE

OA Clinical Presentation

• localized inflammation 

• pain in joint 

• loss of flexibility 

• soft tissue contractures

• osteophytes 

• loss of joint congruity (when severe)

Osteophytes are 

new bone growth 

Rheumatoid Arthritis Clinical Presentation

• windswept fingers, instability, subluxation, or complete dislocation of joints, and muscle imbalance

• periods of exacerbation and remissions

• small joints are the most affected 

Rheumatoid Arthritis Progression

muscle imbalance, instability, subluxation or complete dislocation 

in advanced state - tendon rupture and weak ligaments 

What is the most common type of arthritis in children under 16?

juvenile RA

What is the focus of treatment in RA patient population?

address the symptoms but also work on improving gunction and protection of the limb long term 

T or F. RA is an acute disease. 

FALE - longterm 

Arthritis of the Elbow joint symptoms

same as the other joints mentioned with the addition of - loss of motion in proximal and distal radioulnar joints which affects flexion/extension and pronation/supination, flexion contracture present, collateral ligament laxity, and bursitis.

Loss of motion in the proximal and distal radioulnar joint affects 

flexion/extension and pronation/supination

Drop Sign

The elbow joint space being larger than 4 mm of space indicates arthritis

Arthritis Presentation in the Hand

• wrist will deviate radially 

• fingers will deviate ulnarly

• may include finger deformities

• ‘windswept fingers’

T or F. OA causes more finger deformities than RA. 

FALSE opposite is true 

Arthritis in the Metacarpal Phalangeal Joint 

Deformities are usually manifested by palmar subluxation and increasing ulnar deviation. 

• the extensor tendons often sublux ulnarly into the valleys between the MCP joints

• the flexor tendons may also slip ulnarly when the collateral ligaments are stretched by the inflamed and edematous joint.

Arthritis in the Proximal Interphalangeal Joints 

Deformities are usually Boutonniere or Swan Neck.

Synovitis of the joints leads to a shortening of the collateral ligaments and stretching of the joint capsule.

• lateral bands displace palmarly thus the Boutonniere deformity.

• lateral bands are displaced dorsally thus the Swan neck deformity 

Boutonniere = 

button hole in french  - because the slit in the tendon looks like a button hole with a bone sticking through

Boutonniere Deformity 

Extension of MCP, Flexion of PIP, and Extension of the DIP

Way to remember flex/ext. in Boutonniere Deformity.

EFE

Swan Neck Deformity 

Flexion of MCP, hyperextension of the PIP, and flexion of the DIP

Way to remember the flex/ext. of the Swan Neck Deformity.

FEF

Swan Neck Deformity of the thumb

Flexion of CMC, Hyperextension of MCP, and Flexion of the IP

Boutonniere Deformity of the thumb

Extension of the CMC, Flexion of MCP, Extension of the IP

Deformity of the _______ joint will be flexion or hyperextension depending on the ___________ at the MCP and PIP joint.

Distal Interphalangeal (DIP), pathomechanics

Indications for Splinting

• decrease inflammation

• properly position joints - further deformity

• rest and support weakened structures

• improve function through better stability and position

• aid in postoperative rehab

Orthosis Design Considerations

• biomechanical 3 point force system 

• moment arm - smaller in UE (more force)

• pressure - small surface area

• shear - suspension (biggest struggle for us)

• material properties 

• degree of deformity - may indicate custom fabrication 

T or F. UE orthoses are harder to suspend than LE orthoses.

TRUE

Elbow Orthoses

Custom fit or custom - EO, EWHO

Consider joint position for function 

• with or w/o elbow joint 

• set screws or pins to adjust ROM

• locks, springs 

Joint alignment 

• w/in 1 cm from apex of humeral epicondyle

• may prevent migration/ mal alignment 

Resting Hand Splint positioning

static positioning of the wrist and digits during acute episodes to decrease pain and to align the joints.

Wrist in 10-20° extension and 5° ulnar deviation. 

Thumb abducted and opposed. 

Fingers in flexion.   

Wrist Orthosis

• wrist cock-splint

• 10-30° of extension 

• OTC, custom-fit, or custom fab 

• with or without a thumb spica 

Ulnar Deviation Orthosis 

Supports the MCP joints and provides radially directed force 

3 point forces are on the picture

Thumb Spica Splints

hand or forearm based

provide support to the CMC and MCP joints for acute Rheumatoid Arthritis or Osteoarthritis

JUST ON RADIAL SIDE 

Interphalangeal Boutonniere or Swan Neck Splints

position opposite of the deformity

Casting for a WHFO

Mark landmarks - radial and ulnar styloids, MCP and IP joint, CMC and IP joints of the thumb, any bony prominences

Measure - ML at the styloids and MCP joints

Circumferences at the wrist, MCP

Lengths - wrist to fingertip, wrist to elbow

Modifying a WHFO

• remove - roping from the mold

• draw - trimlines

• accentuate - palmar arch

• apply - build ups on styloids and joint inside the trimlines, buildups on the trimlines

• build out - finger pan to keep to ML measured at MCP joint