The Deltoid Lift: A Cadaveric Analysis and the Literature Review of a Novel Surgical Approach to the Proximal Humerus

Proximal humerus exposure with the inverted-L anterolateral deltoid flip approach, anterolateral deltoid splitting approach, and deltopectoral approach: A comparative cadaveric study

BACKGROUND

Reduction of the posterior aspect of proximal humerus fracture, such as far-retracted greater tuberosity or posterior articular head split fracture via a deltopectoral or deltoid splitting approach, is difficult and usually needs extensive dissection. The inverted-L anterolateral deltoid flip approach, which is developed from the deltoid splitting approach, accesses the proximal humerus via lateral deltoid flap lifting. This study compared the area and arc of surgical exposure to the proximal humerus of this proposed approach to existing approaches.

METHODS

Eleven cadaveric specimens were used. Deltopectoral and deltoid splitting approaches were carried out on the right and left shoulder, respectively. Soft tissue was retracted after completion of a surgical approach to expose the proximal humerus, and dot-to-dot marking pins were placed along the border of exposed area. An additional area with a full shoulder rotation was also marked on the deltopectoral side. An inverted-L deltoid flip approach was further carried out on a deltoid splitting side with a posterior extending incision along the acromion process and the deltoid detachment from the acromion process. The additional area of exposure was subsequently marked. All soft tissue around the proximal humerus was taken down, and the glenohumeral joint was disarticulated. Area of exposure and axial images were taken for further processing and measurement.

RESULT

An average distance of the axillary nerve from the acromion process of the deltoid splitting and the deltopectoral approaches were 49.15 mm and 57.35 mm, respectively (P < 0.05). The average area of exposure of the inverted-L deltoid flip, deltoid-splitting, deltopectoral, and deltopectoral with full rotation approaches were 2729.81mm², 1404.39mm², 1325.41mm², and 2354.78mm², respectively (P < 0.05). Mean arc of exposure lateral to bicipital groove of the inverted-L deltoid flip, deltoid splitting, deltopectoral, and deltopectoral with full rotation approaches were 151.75degrees, 105.02degrees, 61.68°, and 110.64°, respectively (P < 0.05).

CONCLUSION

The inverted-L anterolateral deltoid flip approach provides the most posterior access to the proximal humerus. However, it requires more soft tissue dissection and awareness of tension on the axillary nerve. This approach could be an alternative for displaced posterior head splits or far-retracted greater tuberosity proximal humerus fractures.

The Deltoid Lift: A Comparison Study of Exposure Area in Proximal Humeral Approaches

BACKGROUND

Adequate exposure of the proximal humerus is necessary to address atypical or complex proximal humerus fractures and orthopedic tumors. Surgical management may be difficult through existing approaches due to their limited nature and the delicate neurovascular anatomy of the shoulder. The deltoid lift, a previously described extensile approach, can be incorporated into the surgeon's armamentarium as an alternative exposure to the proximal humerus. The objective of this study was to quantify and compare the humeral exposure achieved through the deltoid lift with the standard direct lateral deltoid-splitting, anterolateral acromial, and deltopectoral approaches in terms of surface area and exposure of key anatomic landmarks.

METHODS

Each approach was performed a minimum of 8 times on 18 cadaveric specimens. After identifying landmarks, exposure area of exposed humerus was quantified using digital images and ImageJ software.

RESULTS

The deltoid lift yielded an average exposure area of 46 cm². Comparison of the exposure area for the deltoid lift against each of the other approaches yielded statistical significance ( P < .01). The exposure provided was 2-folds greater than that of the next most extensive approach. All anatomic landmarks were directly visible through the deltoid lift as compared with the remaining approaches, through which only 1 landmark was directly visualized and only 2 of the 3 remaining were palpable through the approach.

CONCLUSIONS

The deltoid lift extensile surgical exposure to the proximal humerus provides the largest humeral exposure with the greatest visibility of landmarks relative to the 3 most widely utilized standard approaches.