The Hand

1
The Hand

• The power grip This involves the long flexor
  muscles acting at the interphalangeal joints, the
  intrinsic muscles of the palm acting at the
  metacarpophalangeal joints and the extensors of
  the wrist acting at the radiocarpal and midcarpal
  joints. Engagement of the wrist extensors
  lengthens the distance over which the finger
  flexors work allowing more powerful grip.

2
The Hand

• The hook grip This consumes less energy,
  involving the use of just the long finger flexors
• The precision handling grip This grip involves a
  change in the position of a handled object that
  requires fine control of the thumb and fingers.
  In this grip the wrist and fingers are held
  firmly by the long flexors and extensors while
  the intrinsic hand muscles perform the fine
  movements of the digits

3
The Hand

• The position of rest The position automatically
  assumed by the inactive hand when the forearm and
  hand are supported on a flat surface, this
  position is used in casting of proximal wrist and
  forearm fractures.

4
The Hand
5
Fascia of the Palm

• The fascia of the palm is continuous with the
  antebrachial fascia and the dorsal fascia of the
  hand.
• It is thin over the thenar and hypothenar
  eminences but thick centrally (palmar
  aponeurosis) and in the fingers forms the digital
  sheath.
• Palmar aponeurosis This is a strong
  well-defined deep fascial structure that
• Covers the soft tissue of the palm and overlies
  the long flexor tendons
• Is continuous with the flexor retinaculum and
  Palmaris longus tendon.
• Forms 4 longitudinal bands as it radiates
  distally to the bases of the proximal phalanges
  and is continuous with the digital sheaths.

6
Fascia of the Palm

• Fig 6.49 p 828

7
Fascia of the Palm

• Fibrous digital sheaths
• Ligamentous tube that enclose synovial sheaths of
  both the deep superficial flexor tendons and
  the FPL tendon.
• These sheaths are composed of five annular and
  four cruciform parts.

8
Dorsal Digital Appratus of the 3rd Digit

• Fig 6.42 p 811

9
Compartments of the Hand
10
Compartments of the Hand

• Medial fibrous septum
• The tough septum extends from the medial border
  of the palmar aponeurosis to the 5th metacarpal.
  Medial to this septum is the hypothenar
  compartment containing the hypothenar muscles.
• Lateral fibrous septum
• This extends from the lateral border of the
  aponeurosis to the 3rd metacarpal. Lateral to
  this septum is the thenar compartment containing
  the thenar muscles.

• Fig 6.50 p 829

11
Compartments of the Hand

• The Central compartment
• This exists between the medial and lateral
  compartments and contains the flexor tendons and
  their sheaths, the lumbricals, the superficial
  palmar arterial arch and digital arteries and
  nerves.
• Adductor Compartment
• Located deep to the thenar space superficial to
  the interossei muscles, it contains the adductor
  pollicis.

• Fig 6.50 p 829

12

• Fig 6.50 p 829

• Thenar space, Midpalmar space
• These spaces are bounded by the septa from the
  edges of the palmar aponeurosis to the
  metacarpals. The lateral fibrous septa separated
  the thenar and midpalmar spaces. The midpalmar
  space is continuous with the anterior compartment
  of the forearm via the carpal tunnel

13
Dupuytren's Fasciitis and Contracture

• Fig B2.28 p 830

14
Dupuytren's Fasciitis and Contracture

• This is a disease of the palmar fascia resulting
  in progressive thickening and contracture of
  fibrous bands on the palmar surface of the hand
  and fingers. 
• Fasciitis implies inflammation of the fascia and
  contracture implies thickening and tightening of
  the diseased fascia.  The tissue on the palm side
  of the hand thickens (can become as thick as
  0.5cm) and essentially "shrinks" and produces a
  tightness in the area of the hand which the
  diseased tissue overlies. 
• It occurs most often in the fourth and fifth
  digits.  It is a very common problem and often
  arises in the hands of middle aged
  persons however, it can be seen as early as the
  twenties. 
• This entity does run in families in some cases. 
  It is seven times more common in men than women. 
• It has been associated with diabetes and can be
  seen in alcoholics with cirrhosis of the liver. 
• It has also been associated with epilepsy but may
  be a result of the use of anticonvulsant drugs
  rather than the presence of epilepsy itself. 
• The underlying cause is unknown.

15
Dupuytren's Fasciitis and Contracture

• Risk factors
• Family history
• Alcoholism
• Epilepsy
• Diabetes
• A disease of white European males
• 20 of German males _at_50yo
• 40 of German males _at_80yo
• Plantar fibromatosis. Sometimes called Ledderhose
  disease, plantar fibromatosis occurs on the sole
  of the foot and is identical to Dupuytren's
  contracture. Lumps and cords of tissue form on
  the sole, and the toes may be pulled down, making
  it difficult to walk. This rare complication is
  most common in people with a severe familial form
  of Dupuytren's contracture called Dupuytren's
  diathesis.

16
(No Transcript)
17
Dupuytren's Fasciitis and Contracture

• Dupuytren's Disease
• Treatment