1.

Elbow Flexorplasty (Steindler)

A. Skin incision
B. The common origin of the pronator and wrist flexor muscles is dissected and detached
along with a fragment of bone from the medial epicondyle with an osteotome while
taking care to not injure the ulnar and median nerves and brachial vessels
C. The bone fragment with the common origin of the pronator and wrist flexor muscles is
fixed to the anterior surface of the humerus with a screw and suture anchors

2. Principles of Tendon Transfer Procedures

The principles of successful tendon transfer procedures have been identified and refined over the
last century. They are 1) supple joints prior to transfer, 2) soft tissue equilibrium, 3) donor of
adequate excursion, 4) donor of adequate strength, 5) expendable donor, 6) straight line of pull, 7)
synergy, and 8) single function per transfer.
a. Supple joints prior to transfer
The joint that the tendon transfer will move must have maximum passive range of motion
prior to the procedure. A tendon transfer procedure will fail if the joint has become stiff.
Often, aggressive therapy is required to achieve and maintain a supple joint before
performing a tendon transfer procedure. If contracture release is necessary, it should be
performed prior to the tendon transfer procedure, and should be followed by intensive
therapy to maintain range of motion. Because immobilization is required after a tendon
transfer procedure to allow healing of the tendon juncture, contracture release should not
be performed at the same time.
b. Soft tissue equilibrium
The principle of soft tissue equilibrium refers to the idea that a tendon transfer should pass
through a healthy bed of tissue that is free from inflammation, edema, and scar.4 This is
necessary to allow the tendon to glide freely and to minimize adhesions. Following a soft
tissue injury, the surgeon must allow enough time to pass for the inflammation and edema
to fully subside. If the planned tendon transfer must pass through an area of severely
scarred tissue, the scar should be excised and replaced with a flap, or an alternative transfer
through a healthier bed should be considered.
c. Donor of adequate excursion
The excursion or maximum linear movement of the transferred MTU should be adequate to
achieve the desired hand movement. This means that the transferred MTU should have an
excursion similar to that of the tendon which it is replacing. In adults, wrist flexors and
extensors have approximately 33 mm of excursion. The extrinsic finger extensors have about
50 mm of excursion, and the extrinsic finger flexors have about 70 mm of excursion.5 Most
of the time, a donor MTU with adequate excursion will be available for transfer. However, in
some situations none of the available donor MTU’s have the required excursion. In these
cases, the tenodesis effect can often be used to augment the excursion of the transferred
tendon. For example, when a wrist flexor is transferred to restore finger extension, the
excursion of the wrist flexor (33 mm) is insufficient to achieve complete finger extension (50
mm). However, if the patient flexes the wrist during finger extension, the tenodesis effect
tightens the finger extensors, resulting in greater finger extension.
d. Donor of adequate strength
The principle of choosing a donor MTU with adequate strength means that the MTU to be
transferred must be strong enough to achieve the desired movement, but at the same time,
should not be too strong. A donor MTU that is too weak will have inadequate movement
and function, while a donor that is too strong will result in imbalanced movement and
inappropriate posture at rest. When evaluating potential donor MTU’s, it is easiest to
compare their relative strength as opposed to absolute strength.2 The flexor carpi radialis
(FCR), wrist extensors, finger flexors, and pronator teres (PT) all have a relative strength of 1.
The brachioradialis (BR) and flexor carpi ulnaris (FCU) are stronger, and have a relative
strength of 2. Finger extensors are weaker and have a relative strength of 0.5. The abductor
pollicis longus (APL), extensor pollicis longus (EPL), extensor pollicis brevis (EPB), and
palmaris longus (PL) are all weaker still, with relative strengths of 0.1.
e. Expendable donor
The principle of using an expendable MTU as a donor means that there must be another
remaining muscle that can continue to adequately perform the transferred MTU’s original
function. It does no good to restore a given movement if another equally important
movement is lost in the process. Fortunately there is a fair amount of redundancy in the
upper extremity. For example, the wrist has three extensors, the extensor carpi ulnaris
 (ECU), the extensor carpi radialis longus (ECRL), and the extensor carpi radialis brevis (ECRB).
If all three are functional, one or two of the extensors can be transferred. Although wrist
extension will be weakened, it will not be lost as long as there is one remaining extensor.
When evaluating potential donor MTU’s for transfer, one must be mindful of the weakness,
loss of movement, or imbalance that might occur following the transfer.
f. Straight line of pull
Tendon transfer procedures are most effective if there is a straight line of pull. This is
because direction changes diminish the force that the transferred MTU is able to exert on its
insertion. A change in direction of just 40 degrees will result in a clinically significant loss of
force. For example, a PT to ECRB transfer is commonly used to restore wrist extension in
patients with radial nerve palsy. This transfer can be performed in an end-to-side or end-
toend fashion. Assuming that all other factors are equal, the end-to-end transfer will result
in better function and force transfer than the end-to-side transfer, because the line of pull is
straighter. However, with some tendon transfer procedures, a direction change is
unavoidable or even necessary. In these cases, the tendon should be passed around a fixed,
smooth structure that can act as a pulley.
g. Synergy
The principle of synergy refers to the fact that certain muscle groups usually work together
to perform a function or movement. Wrist flexion and finger extension are synergistic
movements that often occur simultaneously during normal activity. When one flexes the
wrist, the fingers automatically extend. Wrist extension and finger flexion are similarly
synergistic. Finger flexion and extension, however, do not normally occur together and are
not synergistic movements. Transferring a wrist flexor to restore finger extension adheres to
the principle of synergy, whereas using a finger flexor to provide finger extension does not. A
synergistic transfer is preferable, although sometimes a non-synergistic transfer is the only
available option.
h. Single function per transfer
The final principle is that a single tendon should be used to restore a single function.
Transfer of one MTU to restore multiple functions will result in compromised strength and
movement.7 The exception to this rule is that a single MTU can be used to restore the same
movement in more than one digit. For example, the FCU cannot be used to power wrist and
finger extension, or to power finger extension and thumb abduction. However, it can be
used to power the extension of all four fingers. It is important to remember these principles
when evaluating a patient for a tendon transfer procedure. Although adherence to these
principles does not guarantee success, ignoring them invites failure.

3. Neer Classification
Neer introduced the concept of fracture segments instead of fragments, segment was
translated by at least 1 cm or angulated by a minimum of 45 degrees.
Fractures of less than 1 cm of displacement and less than 45 degrees of angulation,
independently of number of fragments affected, are considered nondisplaced and are
commonly called one-part fractures. Two-part fractures are named after the site of
displacement as two-part greater tuberosity, two-part lesser tuberosity, two-part surgical neck,
and two-part anatomic neck fractures. Isolated greater tuberosity fractures displace
posteromedially through the unopposed pull of the posterosuperior rotator cuff. Lesser
tuberosity fractures displace medially through the pull of the subscapularis tendon. Two-part
surgical neck fractures frequently exhibit anteromedial displacement of the proximal humeral
shaft secondary to the pull of the pectoralis major.
While, theoretically, five different types of three-part proximal humerus fractures could exist,
Neer reported that three-part fractures invariably occurred with a fracture through the surgical
neck, with a concomitant fracture of either the greater or lesser tuberosity. The intact
tuberosity and the pulling forces of its attached rotator cuff tendons determine three-part
fracture displacement. In three-part greater tuberosity fractures, the head segment is internally
rotated by the action of the subscapularis muscle. In three-part lesser tuberosity fractures, the
head segment is externally rotated and abducted by the action of the posterosuperior rotator
cuff.