This document provides an overview of surgical approaches to the forearm bones - the radius and ulna. It describes the anterior and posterior approaches to the radius, including landmarks, incisions, planes of dissection, and dangers such as the posterior interosseous nerve. The approach to the ulna is also outlined. The goal is to expose the bones while protecting surrounding nerves and muscles through careful subperiosteal dissection in appropriate intermuscular planes.

1. Anatomic Approach of
Forearm
Abdulrahman AlOmair
R2

2. Objectives
 Indication.
 Position.
 Landmarks.
 Incision.
 Internervous plane.
 Superficial Surgical Dissection.
 Deep Surgical Dissection.
 Dangerous.

3. • The surgical anatomies of
the two bones of the
forearm differ significantly.
The ulna has a
subcutaneous border that
extends for its entire
length; the bone can be
reached simply and
directly without
endangering other
structures.

4. In contrast, the upper two
thirds of the radius are
enclosed by a sheath of
muscles.
All surgery in the upper third
of the radius is complicated
further by the posterior
interosseous nerve, which
winds spirally around the
bone close to, if not in
contact with, its
periosteum.

5. Approaches
I. Anterior Approach to the Radius .
II. Posterior approach to the Radius.
III. Approach to the Ulna.

6. Anterior Approach to the
Radius
Henry

7. • Open reduction and internal fixation of fractures
• Bone grafting and fixation of fracture nonunions
• Radial osteotomy
• Biopsy and treatment of bone tumors
• Excision of sequestra in chronic osteomyelitis
• Anterior exposure of the bicipital tuberosity
Uses

8. Position

9. Landmark and incision

10. Internervous Plane

11. Superficial Surgical Dissection
-Incise the deep fascia of the
forearm in line with the skin
incision.
-Identify the medial border of
the brachioradialis muscle.
-Distally : plane B/W
brachioradilis and FCR.
-Proximally : plane B/W
brachioradialis and pronator
teres.

12. Superficial Surgical Dissection
-Dissection : from distal to proximal
-Identify the superficial radial nerve
running on the undersurface of the
brachioradialis and moving with it.
-The brachioradialis receives a number
of arterial branches from the radial
artery (called the recurrent radial
artery) just below the elbow joint.
Ligate this recurrent leash of vessels to
make it easier to move the
brachioradialis laterally

13. Deep Surgical Dissection
Proximal third :
Follow the biceps tendon to
its insertion into the bicipital
tuberosity of the radius. Just
lateral to the tendon is a
small bursa; incise the bursa
to gain access to the proximal
part of the shaft of the
radius.

14. Deep Surgical Dissection
The proximal third of
the radius is covered
by the supinator
muscle, through
which the posterior
interosseous nerve
passes on its way to
the posterior
compartment of the
forearm

15. To displace the nerve
laterally and posteriorly
(away from the surgical
area), fully supinate the
forearm, exposing, at the
same time, the insertion of
the supinator muscle into
the anterior aspect of the
radius
Deep Surgical Dissection

16. Next, incise the
supinator muscle
along the line of its
broad insertion.
Continue
subperiosteal
dissection laterally,
stripping the muscle
off the bone
Deep Surgical Dissection

17. Lateral retraction of the muscle lifts the posterior
interosseous nerve clear of the operative field, but be
careful! Excessive traction may cause a neurapraxia of
the nerve, and it recovers very slowly, taking up to 6 to 9
months. Finally, do not place retractors on the posterior
surface of the radial neck, because they may compress
the posterior interosseous nerve against the bone in
patients whose nerve comes into direct contact with the
posterior aspect of the radial neck.
Deep Surgical Dissection

18. Middle third :
Deep Surgical Dissection
The anterior aspect
of the middle third of
the radius is covered
by the pronator teres
and flexor digitorum
superficialis muscles.

19. Deep Surgical Dissection
To reach the anterior
surface of the bone,
pronate the arm so that the
insertion of the pronator
teres onto the lateral aspect
of the radius is exposed

20. Detach this insertion
from the bone and strip
the muscle off medially.
Preserve as much soft
tissue as you can
compatible with
accurate reduction and
fixation of the fracture.
Deep Surgical Dissection

21. Deep Surgical Dissection
Distal third :
Two muscles, the flexor
pollicis longus and the
pronator quadratus,
arise from the anterior
aspect of the distal
third of the radius.

22. To reach bone, partially
supinate the forearm and
incise the periosteum of the
lateral aspect of the radius
lateral to the pronator
quadratus and the flexor
pollicis longus. Then, continue
the dissection distally,
retracting the two muscles
medially and lifting them off
the radius
Deep Surgical Dissection

23. Dangers
Posterior Interosseous Nerve
is vulnerable as it winds around the
neck of the radius within the substance
of the supinator muscle. The key to
ensuring its safety is to detach correctly
the insertion of the supinator muscle
from the radius. The insertion of the
muscle is exposed
completely only when the arm is
supinated fully. Once the subperiosteal
dissection is begun, the nerve is
comparatively safe, but overzealous
retraction still can lead to a neurapraxia

24. Superficial Radial Nerve
Runs down the forearm
under the brachioradialis
muscle. It becomes
vulnerable when the
“mobile wad” of three
muscles is mobilized and
retracted laterally

25. radial artery
Runs down the middle
of the forearm under
the brachioradialis
muscle.

26. recurrent radial arteries
a leash of vessels
that arise from the
radial artery just
below the elbow
joint

27. How to Enlarge the Approach
The anterior approach provides complete
access to the entire length of the radius.
The approach can be extended distally to
expose the wrist joint.
Although it can be extended into an
anterolateral approach to the elbow and
humerus, such extension rarely is required.

28. Posterior Approach to the
Radius

29. Uses
-Open reduction and internal fixation of radial fractures (the
approach provides access to the extensor side of the bone
-Treatment of delayed union or nonunion of fractures of the
radius
-Access to the posterior interosseous nerve; decompression of
the nerve.
-Radial osteotomy
-Treatment of chronic osteomyelitis of the radius
Biopsy and treatment of bone tumors

30. Position

31. Landmark and Incision

32. Internervous Plane

33. Superficial Surgical Dissection
Incise the deep fascia in line
with the skin incision.
Identify the space between
the extensor carpi radialis
brevis and the extensor
digitorum communis. This gap
is more obvious distally, where
the abductor pollicis longus
and the extensor pollicis brevis
emerge from between the two
muscles.

34. Continue the dissection
proximally, separating the
two muscles to reveal the
upper third of the shaft of
the radius, which is
covered by the enveloping
supinator muscle.
Superficial Surgical Dissection

35. Below the abductor pollicis
longus and the extensor
pollicis brevis, identify the
intermuscular plane between
the extensor carpi radialis
brevis and the extensor pollicis
longus.
Separating the two muscles
exposes the lateral aspect of
the shaft of the radius
Superficial Surgical Dissection

36. Deep Surgical Dissiction
Two methods exist for successfully identifying and
preserving this nerve as it traverses the muscle.

37. Deep Surgical Dissiction
Proximal to distal :Detach the
origin of the extensor carpi
radialis brevis and part of the
origin of the extensor carpi
radialis longus from the lateral
epicondyle and retract these
two muscles laterally. Next,
identify the posterior
interosseous nerve proximal to
the proximal end of the
supinator muscle by palpating
the nerve

38. Deep Surgical Dissiction
Distal to proximal: Identify the
nerve as it emerges from the
supinator. Note that it
emerges about 1 cm proximal
to the distal end of the
muscle. Now, follow the nerve
proximally through the
substance of the muscle,
taking care to preserve all
muscular branches.

39. When the nerve has been
identified and preserved
successfully, fully supinate the
arm to bring the anterior
surface of the radius into view.
Detach the insertion of the
supinator muscle from the
anterior aspect of the radius.
Strip the supinator off the
bone subperiosteally to
expose the proximal third of
the shaft of the radius
Deep Surgical Dissiction

40. Middle third :
Deep Surgical Dissiction
Two muscles, the abductor
pollicis longus and the
extensor pollicis brevis,
blanket this approach as they
cross the dorsal aspect of the
radius before heading distally
and radially across the middle
third of the radius.

41. To retract them off the bone,
make an incision along their
superior and inferior borders.
Then, they can be separated
easily from the underlying
radius and retracted either
distally or proximally,
depending on the exposure
that is required
Deep Surgical Dissiction

42. Distal third :
Deep Surgical Dissiction
Separating the extensor carpi
radialis brevis from the
extensor pollicis longus
already has led directly onto
the lateral border of the radius

43. Dangers
Posterior Interosseous Nerve

44. How to Enlarge the Approach
Local measures :
To widen the plane between
the extensor carpi radialis
brevis and extensor digitorum
communis muscles, detach the
origin of the extensor carpi
radialis brevis from the
common extensor origin on
the lateral epicondyle of the
humerus.

45. Extensile measures :
How to Enlarge the Approach
The approach can be extended to the dorsal side of the
wrist It can be extended proximally to expose the
lateral epicondyle of the humerus .These extensions,
however, rarely are required.

46. Approach to the Ulna

47. Uses
- Open reduction and internal fixation of ulnar fractures.
- Treatment of delayed union or nonunion of ulnar fractures.
- Osteotomy of the ulna.
- Treatment of chronic osteomyelitis.
- Treatment of the fibrous anlage of the ulna in cases of ulnar
clubhand.
- Ulnar lengthening (in Kienböck's disease).
- Ulnar shortening (in cases of distal radial malunion).

48. Position

49. Landmark and Incision

50. Internervous plane

51. Superficial Surgical Dissection
Beginning in the distal half
of the incision, incise the
deep fascia along the
same line as the skin
incision; continue the
dissection down to the
subcutaneous border of
the ulna

52. Even though the bone feels subcutaneous in its
middle third, the fibers of the extensor carpi ulnaris
muscle nearly always have to be divided to reach the
bone.
In the region of the olecranon, the flexor carpi ulnaris
and anconeus muscles run along the plane of
dissection. The plane still is an internervous plane,
because the anconeus is supplied by the radial nerve
and the flexor carpi ulnaris is supplied by the ulnar
nerve.
Superficial Surgical Dissection

53. Deep Surgical Dissection
Incise the periosteum over the
ulna longitudinally. Continue
the dissection around the
bone in a subperiosteal plane
to reveal either the flexor or
the extensor aspects of the
bone, as needed

54. Dangers
Ulnar Nerve
Travels down the forearm
under the flexor carpi ulnaris,
lies on the flexor digitorum
profundus.

55. The nerve is safe as long as the flexor carpi ulnaris is stripped
off the ulna subperiosteally.
If the dissection strays into the substance of the muscle,
however, the nerve may be damaged.
Because the nerve is most vulnerable during very proximal
dissections, it should be identified as it passes through the
two heads of the flexor carpi ulnaris before the muscle is
stripped off the proximal fifth of the bone
Ulnar Nerve

56. Ulnar Artery
Travels down the forearm with
the ulnar nerve, lying on its
radial side. Therefore, it also is
vulnerable when dissection of
the flexor carpi ulnaris is not
carried out subperiosteally

57. How to Enlarge the Approach
Local Measures
The approach described provides excellent
exposure of the entire bone and cannot be
enlarged usefully by local measures.

58. Extensile Measures
How to Enlarge the Approach
The approach cannot be extended usefully
distally. It can be extended over the olecranon
and up the back of the arm, however, either to
expose the elbow joint through an olecranon
osteotomy or to approach the posterior aspect
of the distal two thirds of the humerus.

59. THANK YOU