Chapter 9: Upper Limb

Overview

The human upper limb is structured for manipulation of objects in three dimensions. The limb allows for various grasping mechanisms (precision, power, pinch) in distal regions to be combined with spatial movements by the proximal regions. Objects are sensed, held and analyzed or used. They can also be brought to a secondary area (usually the face) for further analysis or use.

The limb is a module. The regions in the upper limb are extensor or flexor. The two groups are analogous to those in the lower limb but situated opposite those in its lower counterpart, due to embryological rotation (lateral in the upper limb and medial in the lower).

The regions in the upper limb are grouped in the:

• i) Shoulder girdle (scapula, pectoral, deltoid, axilla)

• ii) Arm (anterior, posterior)

• iii) Elbow (cubital fossa)

• iv) Forearm (anterior, posterior)

• v) Wrist (carpal tunnel, anatomical snuffbox)

• vi) Hand (dorsum, palm, fingers)

Assessment of the limb is made easier by its accessibility compared to trunk modules, usually providing clear symptoms and signs.

Clavicle Fractures

The clavicle is one of the commonly fractured bones in the sequence of energy transfer that occurs with a fall on the outstretched hand or by direct trauma. This is because the shaft has a sharp negative change in curvature at the junction of the medial 2/3 and lateral 1/3 (where it most often fractures).

The clinical features are usually typical but vary with:

• i) Injury factors (high energy, comminution, displacement)

• ii) Patient factors (osteoporosis, previous injuries, co-existing disease)

The x-ray typically shows an oblique fracture of the middle third.

Possible immediate complications include:

• i) Skin break (skin necrosis, ulceration, open fracture)

• ii) Subclavian vessel injury

• iii) Brachial plexus injury (divisions)

Treatment options depend on the assessment of both the injury and the patient*.

Possible late complications include:

• i) Poor union

  

• ii) Nerve dysfunction (brachial plexus caught in callus)

• iii) Immobility consequences (stiffness and muscle wasting)

Acromioclavicular Joint Injuries

The acromioclavicular (AC) joint is a common site of sprain (tearing of ligament fibers), subluxation (partial contact) and dislocation (no contact). It rarely ...