Analysis of shoulder abduction by dynamic shoulder radiograph following suprascapular nerve repair in brachial plexus injury

Midterm Outcomes of Surgical Reconstruction and Spontaneous Recovery of Upper-Extremity Paralysis Following Acute Flaccid Myelitis

Background

Acute flaccid myelitis (AFM) is a disabling, poliomyelitis-like illness that mainly affects children. Although various surgical interventions are performed for intractable paralysis due to AFM, the timing of surgery and its long-term outcomes have yet to be established, especially for shoulder reconstruction. This study aimed to analyze the midterm outcomes of nonsurgically and surgically treated upper-extremity AFM and the factors influencing shoulder functional outcomes after surgical reconstruction.

Methods

We retrospectively examined 39 patients with AFM in 50 upper extremities between 2011 and 2019. The degree of spontaneous recovery of completely paralyzed muscles was evaluated at a median of 3, 6, and 37 months after the onset of paralysis. Twenty-seven patients with 29 extremities underwent surgery involving nerve transfer, muscle-tendon transfer, or free muscle transfer for shoulder, elbow, and hand reconstruction.

Results

Patients with complete paralysis of shoulder abduction at 6 months did not show later recovery. Twenty-two patients with 24 extremities underwent shoulder surgery, and all but 1 were followed for at least 24 months after surgery. Although postoperative shoulder abduction recovery was similar between transfer of the spinal accessory nerve and of the contralateral C7 nerve root to the suprascapular nerve, the outcomes obtained with spinal accessory nerve transfer had more variability, likely related to latent spinal accessory nerve paralysis, shoulder instability related to pectoralis major paralysis, and the type of paralysis. Shoulder abduction recovery was also greatly affected by scapulothoracic joint movement. In contrast, the outcomes of the elbow flexion and hand reconstructions were more consistent and acceptable.

Conclusions

All patients had loss of shoulder abduction, and restoration of shoulder function was less predictable and depended on the quality of the donor nerves and recovery of the synergistic muscles. Strict donor nerve selection and additional nerve transfer for shoulder reconstruction are imperative for satisfactory outcomes.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Does the Suprascapular Nerve Move within the Suprascapular Notch? Biomechanical Perspective Using the Finite Element Method

PURPOSE

We aimed to analyze changes in suprascapular nerve (SSN) position within the suprascapular notch during in vivo shoulder abduction.

MATERIALS AND METHODS

Three-dimensional models of the shoulder complex were constructed based on magnetic resonance imaging of the brachial plexus (BP-MR) in a patient diagnosed with SSN dysfunction but normal scapular movement. Using BP-MR in neutral position and computed tomography data on shoulder abduction, shoulder abduction was simulated as the transition between two positions of the shoulder complex with overlapping of a neutral and abducted scapula. SSN movement during abduction was evaluated using the finite element method. Contact stress on the SSN was measured in the presence and absence of the transverse scapular ligament (TSL).

RESULTS

In the neutral position, the SSN ran almost parallel to the front of the TSL until entering the suprascapular notch and slightly contacted the anterior-inferior border of the TSL. As shoulder abduction progressed, contact stress decreased due to gradual loss of contact with the TSL. In the TSL-free scapula, there was no contact stress on the SSN in the neutral position. Towards the end of shoulder abduction, contact stress increased again as the SSN began to contact the base of the suprascapular notch in both TSL conditions.

CONCLUSION

We identified changes in the position of the SSN path within the suprascapular notch during shoulder abduction. The SSN starts in contact with the TSL and moves toward the base of the suprascapular notch with secondary contact. These findings may provide rationale for TSL release in SSN entrapment.

Shrug radiographs for the diagnosis of long thoracic nerve palsy in traumatic brachial plexus injury

BACKGROUND

Preoperative diagnosis of long thoracic nerve (LTN) palsy is important for shoulder reconstruction after a traumatic brachial plexus injury (BPI). In the present study, we developed an objective diagnostic method for LTN palsy for patients with traumatic BPI.

METHODS

This is a retrospective review of 56 patients with traumatic BPI who had been receiving treatment at a single institution for over 8 years. The patients were divided into 2 groups: an LTN palsy group (n = 30) and a no palsy control group (n = 26). The LTN palsy group had 21 different palsy types with 4 and 5 C5-7 and C5-8, whereas the no palsy group had 18 different palsy types with 5 and 3 C5-6 and C5-8, respectively. Preoperative plain anteroposterior radiographs were taken in shoulder adduction and shrug positions. Scapulothoracic (ST) upward rotation and clavicle lateral (CL) rotation angles were measured on X-rays. The differences between the adduction and shrug positions for the respective angles were calculated and defined as Φ_ST and Φ_CL, respectively. The differences in the Φ_ST and Φ_CL values due to the presence or absence of LTN palsy were examined, the cutoff values of Φ_ST and Φ_CL for the diagnosis of LTN palsy were determined, and further sensitivity and specificity were calculated.

RESULTS

Both Φ_ST and Φ_CL were significantly decreased in the LTN palsy group compared with the no palsy control group. The sensitivity and specificity for LTN palsy were 0.833 and 1.000 for Φ_ST and 0.833 and 0.840 for Φ_CL, respectively, when the cutoff value was set as Φ_ST = 15° and Φ_CL ≤ 24°.

CONCLUSION

Dynamic shrug radiographs provide a useful objective diagnosis of LTN palsy after traumatic BPI.

Viable C5 and C6 Proximal Stump Use in Reconstructive Surgery of the Adult Brachial Plexus Traction Injuries

BACKGROUND

In patients with only upper (C5, C6) brachial plexus palsy (BPP), the pooled international data strongly favor nerve transfers over nerve grafts. In patients with complete BPP, some authors favor nerve grafts for the restoration of priority functions whenever there is a viable proximal stump.

OBJECTIVE

To evaluate functional recovery in cases of upper and complete BPP where only direct graft repair from viable proximal stumps was performed.

METHODS

The study included 36 patients (24 with complete BPP and 12 with only upper BPP) operated on over a 15-yr period. In all cases, direct graft repair from C5 to the musculocutaneous and the axillary nerve was performed. In cases with complete BPP, additional procedures included either direct graft repair from C6 to the radial nerve and the medial pectoral nerve or the dorsal scapular nerve transfer to the branch for the long head of the triceps.

RESULTS

The use of C5 proximal stump grafts (in both complete and upper BPP) resulted in satisfactory elbow flexion in 26 patients (72.2%) and satisfactory shoulder abduction in 22 patients (61.1%). The use of C6 proximal stump grafts in patients with complete BPP resulted in satisfactory elbow extension in 5 (50%) and satisfactory shoulder adduction in another 5 (50%) patients.

CONCLUSION

Although nerve transfers generally enable better restoration of priority functions, in cases of infraganglionary injuries, especially in shorter defects, it is also necessary to consider direct graft repair, or at least its combination with nerve transfers, as a potentially beneficial treatment modality.