Identifying the axillary nerve during shoulder surgery: an anatomic study using advanced imaging

Reverse shoulder arthroplasty for proximal humerus fractures: a comparison of the deltoid split and deltopectoral approaches

INTRODUCTION

Reverse shoulder arthroplasty (RSA) is a common treatment for three- and four-part proximal humerus fractures. RSA is commonly performed through a deltopectoral (DP) surgical approach; however, a deltoid split (DS) approach has been described. The purpose of this study was to compare the intraoperative and postoperative outcomes of patients undergoing RSA for proximal humerus fractures through a DP and DS approach.

MATERIALS AND METHODS

A retrospective study of patients who underwent RSA for proximal humerus fractures at our level 1 trauma center was performed. Patients were evaluated at a minimum 1-year follow-up. Intraoperative outcomes as well as patient-reported outcome measures (PROMs) were analyzed. Postoperative complications, reoperation rates, and radiographic outcomes were evaluated.

RESULTS

Sixteen patients were included in the DP group and 13 patients in the DS group. The average follow-up was 28.6 months in the DP group and 21.1 months in the DS group. There were no significant differences in patient demographics or injury characteristics. Operative time was significantly shorter in the DS group (103 min) compared to the DP group (123 min). Tuberosity repair was performed in 81.3% of patients in the DP group and 92.3% of patients in the DS group. No significant differences were found in PROMs at final follow-up. There were no significant differences in postoperative complications. Three patients in the DP group and one patient in the DS group required reoperation. Lastly, 81.8% of patients achieved tuberosity union in the DS group and 66.7% in the DP group; however, this did not reach statistical significance.

CONCLUSION

This study demonstrates that RSA for proximal humerus fractures performed through a DS or DP approach may result in similar intraoperative and postoperative outcomes, with no difference in reoperation or complication rates.

Soft Tissue Management in Shoulder Arthroplasty

Total shoulder arthroplasty is a rapidly growing field, with more procedures performed each year. An important aspect of shoulder arthroplasty surgery is the management of soft tissues. Good functional outcomes in shoulder arthroplasty are significantly dependent on the repair of the rotator cuff tendons and proper release of the shoulder capsule. The success of any shoulder arthroplasty is predicated upon the meticulous handling of these tissues. The surgeon's ability to execute appropriate soft tissue techniques will facilitate easier surgery by increasing exposure and lead to better outcomes for the patient.

An Anatomic Study of the Lateral Dorsal Cutaneous Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications

BACKGROUND

The lateral dorsal cutaneous nerve (LDCN) and the anastomotic branch of the sural nerve (AB) are cutaneous sensory nerves at risk of iatrogenic injury during lateral foot surgery. This study is the first to use a large cohort of high-resolution magnetic resonance images (MRIs) of the ankle to better describe the course of these nerves in vivo in order to aid surgeons intraoperatively. Our study intends to build on the "high and inside" approach to the proximal 5MT by accounting for variations in course of the LDCN and AB.

METHODS

One hundred twenty-five 3-tesla (T) MRI studies of the ankle were analyzed. Three reviewers measured the distance from the LDCN and AB to landmarks including the most proximal aspect of the fifth metatarsal tuberosity (5MT) and the peroneus brevis tendon (PBT).

RESULTS

Mean vertical distance from the LDCN to the 5MT was 0.8 ± 0.2 cm. Presence of an AB was visualized in 59 of 125 studies (47.2%) and was found 2.2 ± 0.5 cm dorsal to the 5MT. The AB was found to become superior to PBT at a horizontal distance 1.9 ± 0.5 cm proximal to the 5MT. The LDCN was found superior to the PBT at its insertion onto the 5MT in approximately 10% (n = 12) of our studies. During these instances, the LDCN was located an average of 0.3 cm dorsal to the PBT.

CONCLUSION

Our proposed "safe zone" for the approach to the proximal 5MT remains superior to the LDCN and inferior to the AB and avoids crossing directly over either nerve in >95% of analyzed MRI studies. This incision begins 1.5 cm dorsal to the most proximal aspect of the 5MT and extends no more than 1 cm posteriorly. Careful dissection and identification of the LDCN and possible AB is necessary prior to further extension of incision.

LEVEL OF EVIDENCE

Level IV, case series.

An Anatomic Study of the Sural Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications

BACKGROUND

The sural nerve (SN) is a sensory cutaneous nerve that is at risk of iatrogenic injury during surgery at the lateral ankle. Prior anatomic studies of the SN are limited primarily to cadaveric studies with small sample sizes. Our study analyzed a large cohort of magnetic resonance images (MRIs) of the ankle to obtain a more generalizable, in vivo sample of distal SN course.

METHODS

A total of 204 3-tesla MRI studies of the ankle were analyzed. Three reviewers measured the distance from the SN to various landmarks including the distal tip of the lateral malleolus (DTLM) and the lateral border of the Achilles tendon (LBA).

RESULTS

Mean vertical distance from SN to DTLM was 2.2 cm (range, 0.9-3.6 cm). Mean horizontal distance from SN to DTLM and to LBA at the level of DTLM was 1.7 cm (range, 0.8-3.0 cm) and 1.9 cm (range, 1.0-2.9 cm), respectively. Mean horizontal distance from SN to LBA at the level of superior Achilles tendon insertion onto the calcaneus (SAI) was 2.6 cm (range, 1.4-3.7 cm), and mean horizontal distance from SN to LBA at 5 cm above SAI was 0.9 cm (range, 0.4-1.8 cm).

CONCLUSION

The variation in SN course observed in our study allowed us to propose "safe zones" for several surgical approaches including the extensile lateral approach to the calcaneus (ELAC), the sinus tarsi approach (STA), the direct lateral approach to the lateral malleolus (DLA), and the posterolateral approach to the ankle (PLA), which we hope will minimize iatrogenic injury to the SN.

LEVEL OF EVIDENCE

Level IV, case series.