Keywords
brachial plexus injury - Latarjet procedure - subscapularis splitting method
Introduction
Proposed by Michael Latarjet in the year 1954 and subsequently modified over the past
few decades, the Latarjet procedure is commonly performed now for recurrent anterior
dislocation of the shoulder,[1] with varying rates of postprocedural complications. Magnetic resonance imaging (MRI)
and high-resolution ultrasound imaging play a crucial role in the timely diagnosis
of postoperative complications.
Case Summary
A 21-year-old gentleman with a history of recurrent right anterior dislocation had
undergone the Latarjet procedure and complained of weakness in his right hand and
thumb on the second postoperative day. The patient was kept under close follow-up.
However, in 6 months, there was no further improvement. During a neurological assessment,
he was found to have median nerve palsy and musculocutaneous nerve palsy.
Imaging Findings
MRI showed a diffusely thickened, stretched, and tethered lateral cord of the right
brachial plexus toward the postoperative site ([Fig. 1A]). Also, the distal part of the lateral cord was sutured to the subscapularis muscle
([Fig. 1B]). Musculocutaneous, median, and, to a lesser extent, the ulnar nerves were thickened
and showed short tau inversion recovery hyperintense signal with denervation changes
in the coracobrachialis and short head of biceps muscle ([Fig. 1C]). Sutures entrapping the lateral cord were well visualized in the high-resolution
ultrasound as well ([Fig. 1D]).
Fig. 1 Magnetic resonance (MR) images (A – T1 coronal, B, and C – short tau inversion recovery [STIR] axial) show diffusely thickened, stretched,
and tethered lateral cord of right brachial plexus (yellow arrow) toward the postoperative
site (A). Also, the distal part of the lateral cord was sutured (yellow arrow) to the subscapularis
muscle (B). The rest of the immediate distal terminal branches could not be well delineated.
However, further caudally, the musculocutaneous nerve, median nerve, and, to a lesser
extent, the ulnar nerve were thickened and showed STIR hyperintense signal with denervation
changes (yellow arrow) in the coracobrachialis and short head of biceps muscle (C). Sutures entrapping the lateral cord were well visualized (yellow arrow) in the
high-resolution ultrasound as well (D).
Intraoperative Findings
The patient underwent right brachial plexus exploration, and it was found that the
subscapularis was cut in the upper two-thirds craniocaudally and sutured ([Fig. 2A]). One of the suture anchors was seen passing through the distal part of the lateral
cord, constricting and scarring the lateral cord and medial root of the median nerve.
This tether had lateralized the distal median and musculocutaneous nerves, which were
caught under the second and third sutures ([Fig. 2B] and [C]). There was complete severance of the median and musculocutaneous nerves. Scarred
part of the lateral cord was excised and group fascicular grafting of median and musculocutaneous
nerves was done. Due to the duration of the injury, a distal neurotization of the
flexor carpi ulnaris fascicle of the ulnar nerve to the biceps branch of the musculocutaneous
nerve was also done. The postop period of the patient was eventful and will be reviewed
for supervised therapy.
Fig. 2 (A–C) The intraop pictures of sutures entrapping the lateral cord, musculocutaneous nerve,
and medial and lateral roots of the median nerve.
Diagnosis
Suture entrapment of lateral cord, musculocutaneous nerve, and medial, and lateral
roots of the median nerve of the right brachial plexus. The patient was followed up
serially and after 12 months of the surgery, the patient showed complete resolution
of the weakness in the right hand and thumb and there were no new complaints.
Discussion
Typical steps of Latarjet procedure ([Fig. 3A]–[F]) include access through deltopectoral groove, shaving off the pectoralis minor from
medial aspect of the coracoid process, osteotomy at the knee of coracoid with preservation
of conjoint tendon, splitting of the subscapularis at the junction between the upper
two-thirds and lower one-third along the muscle fibers, capsulotomy of the glenohumeral
joint, fixation of the harvested coracoid, closure of capsule, and no suturing of
subscapularis.[1]
[2]
[3]
[4]
[5] In our case, suturing of the subscapularis led to inadvertent sutural entrapment
of the lateral cord, musculocutaneous nerve, and medial, and lateral roots of the
median nerve ([Fig. 3G]–[I]) and resultant denervation changes in coracobrachialis and short head of biceps
muscle ([Fig. 1C]).
Fig. 3 Steps in Latarjet procedure (A – approach through anterior deltopectoral groove and shave off the pectoralis minor
from the medial aspect of the coracoid process, B – osteotomy at the knee of coracoid with preservation of conjoint tendon, C – splitting of subscapularis at the junction between the upper two-thirds and lower
one-third along the muscle fibers, D – capsulotomy of the glenohumeral joint, E – fixation of the harvested coracoid, F – closure of capsule and no suturing of subscapularis). However, schematic images
(G–I) show the longitudinal incision of the subscapularis (G), fixation of the coracoid graft to the glenoid (H), and (I) inadvertent entrapment of the lateral cord of the brachial plexus, musculocutaneous
nerve, and medial and lateral roots of the median nerve while suturing the defect
in the subscapularis muscle.
The incidence rate of neurovascular injury could vary anywhere between 1% and as high
as 20%.[1] Musculocutaneous nerve and axillary nerve are the most commonly injured nerves during
the Latarjet procedure.[1]
[2]
[3]
[4]
[5]
[6]
[7]
While dissecting around the coracoid, surgeon must stay lateral to the conjoint tendon
and avoid exposing the medial border of the conjoint tendon to prevent nerve injury.[1] Self-retaining retractor sizes and positions must be selected appropriately according
to the patient's habitus to avoid nerve stretching.[2] Avoiding tenotomy and suturing of the subscapularis by using the subscapularis split
method for the glenohumeral joint prevents nerve injury.[3]
[4]
[5]
Conclusion
Careful dissection of the coracoid by limiting the exploration medial to the conjoint
tendon, selective usage of self-retaining retractors, and subscapularis split method
to access the glenohumeral joint could prevent nerve injury during the Latarjet procedure.
MRI and high-resolution ultrasound play a vital role in the early identification of
this complication.
