Posterior Interosseous Nerve Graft: Utilizing External Landmarks and Anthropometric Ratios to Predict Available Length for Digital Nerve Reconstruction in a Cadaveric Study.

Objective: In digital nerve defects that require grafting, autografts remain the efficacious option. The sensory posterior interosseous nerve (PIN) is an ideal choice as it is of similar caliber to digital nerves and leaves no donor morbidity upon resection. However, a finite length of harvestable PIN exists, and considerable variations of this length have been reported in the literature. There exists no predictive model to estimate this length. We sought to determine a method to accurately predict the available length of PIN based on individual patient anthropometry. Methods: A cadaveric dissection study was performed in a fresh tissue laboratory. The length of the sensory branch of the PIN and various anthropometric measurements were made in respect to surface anatomy of the ulna to develop a predictable ratio for available PIN donor graft. Results: A total of 16 specimens were obtained. On average the length of the PIN was 5.7 cm (range: 3.3-9. cm) and the length of the ulna was 25.7 cm (range: 23.5-30.6 cm). The ratio of PIN to ulnar length was 0.222 (r = 0.4651). Using one-fifth the length of the ulna, the mean predicted length of the PIN was 5.14 cm (range: 4.7-6.1 cm). On univariate analysis, there was no significant difference between the measured and predicted PIN length (P = .249). Conclusion: An anthropometric ratio predicated on reproducible surface anatomy of the ulna is a useful tool in predicting the sensory PIN length. Such a prediction may be a useful in guiding patient discussions concerning surgical options for digital nerve reconstruction.

Objectif: Dans les cas d'anomalies des nerfs digitaux qui exigent une greffe, les autogreffes sont les plus efficaces. Le nerf interosseux postérieur (NIP) sensitif est le choix idéal, car son calibre est semblable à celui des nerfs digitaux et qu'il ne provoque aucun problème de santé au site de résection. Cependant, la longueur du NIP pouvant être récolté est limitée, et d'énormes variations sont présentées dans les publications. Aucun modèle prédictif ne permet d'évaluer cette longueur. Les chercheurs ont entrepris d'établir une méthode pour prédire avec fiabilité la longueur disponible du NIP d'après les caractéristiques anthropométriques de chaque patient. Méthodologie: Les chercheurs ont procédé à une étude de dissection cadavérique dans un laboratoire de tissus frais. Ils ont mesuré le rameau sensitif du NIP et diverses dimensions anthropométriques d'après l'anatomie de surface de l'ulna pour établir un ratio prévisible de greffe du NIP disponible chez le donneur. Résultats: Les chercheurs ont obtenu 16 prélèvements et calculé une longueur moyenne du NIP de 5,7 cm (plage de 3,3 cm à 9,6 cm) et une longueur moyenne de l'ulna de 25,7 cm (plage de 23,5 cm à 30,6 cm). Ils ont calculé un ratio de 0,222 (r = 0,4651) entre la longueur du NIP et de l'ulna. D'après le cinquième de la longueur de l'ulna, ils ont prédit une longueur moyenne du NIP de 5,14 cm (plage de 4,7 cm à 6,1 cm). À l'analyse univariée, ils n'ont constaté aucune différence significative entre la longueur mesurée et prédite du NIP (P = 0,249). Conclusion: Le ratio anthropométrique établi d'après l'anatomie de la surface reproductive de l'ulna est un outil utile pour prédire la longueur du NIP sensitif. Une telle prédiction peut être utile pour orienter les échanges avec le patient au sujet des possibilités chirurgicales de la reconstruction du nerf digital.

Anatomic surface landmarks to guide injection for posterior interosseous nerve block.

Proper injection of the posterior interosseous nerve (PIN) is important for both the therapeutic and diagnostic management of wrist pain. However, no anatomical study exists describing the site of injection based on individual wrist width. We sought to develop a reproducible anthropometric ratio utilizing external wrist surface anatomy to predict a safe and accurate injection site for the PIN. Fresh frozen cadaver forearms were dissected at the University of Louisville tissue lab. Several anthropometric measurements were obtained in order to develop a reproducible ratio to calculate location of injection. A total of 16 cadaver forearms of equal male to female ratio were obtained. On average, the male forearm had a greater mean wrist circumference obtained at the level of Lister's tubercle compared to female forearms, 17.1 cm vs. 13.5 cm. An injection given ulnar to proximal edge of Lister's tubercle at a length of one-fourth the distance between Lister's tubercle and radial aspect of ulnar styloid resulted in 100% accurate perineural injection without intraneural injection. An anthropometric ratio of one-fourth the distance from Lister's tubercle to the ulnar styloid was able to predict accurate injection sites for the distal PIN in cadaveric specimens of varying anatomical proportions.

Surface Landmarks to Provide a Safe Ulnar Nerve Block in the Wrist: Anatomical Study and Literature Review.

Introduction: Use of local anesthesia in awake patients undergoing hand surgery has become increasingly popular. A thorough understanding of local anatomy, such as the distal wrist for ulnar nerve block, is required to provide safe blockade. We sought to conduct an anatomic study of the distal wrist and review cadaveric studies describing various techniques for ulnar nerve block. Methods: Dissection of fresh-frozen cadaver forearms at the University of Louisville Robert Acland Fresh Tissue Lab assessing relationships between the flexor carpi ulnaris tendon and the ulnar nerve and the ulnar artery was performed. Three cadaveric studies on ulnar nerve blockade using the ulnar, volar, and/or transtendinous technique were identified and reviewed. Results: A total of 16 cadaver forearms of equal male to female ratio were obtained. The ulnar nerve was noted to be directly posterior to the flexor carpi ulnaris tendon in 15 (93.8%) forearms, with 1 (6.3%) specimen having the nerve extend along the ulnar border of the flexor carpi ulnaris. The ulnar artery was radial to the ulnar nerve 1 cm proximal to the pisiform in all specimens. In all 3 cadaveric studies, only the ulnar technique was associated with no ulnar artery and/or ulnar nerve injury. Conclusion: Knowledge of distal wrist anatomy can help minimize risk of iatrogenic injury during local blockade. On review, the ulnar approach provides the safest method for ulnar nerve block.

Breast Reconstruction With Local Flaps: Don't Forget Grandma.

Objective: Lateral breast defects of various causes can be reconstructed with random patterned local flaps utilizing oncoplastic techniques. These local flaps are used frequently in other areas but are infrequent in breast reconstruction despite affording excellent utility in small lateral defects. We sought to demonstrate this with a case series involving 5 patients who underwent oncoplastic breast surgery with random patterned flap reconstruction. Methods: From 2016 to 2017, 3 different varieties of random flaps were used in 5 women requiring lateral breast defect reconstruction secondary to resection of localized cancer or cutaneous lesion. The local flaps included a rhomboid flap, the bilobed flap, and a rotational flap. Patients were then evaluated in the clinic 10 to 12 months postoperatively for complications, symmetry, and satisfaction of reconstruction. Results: In 4 of 5 patients, the local flap remained fully viable and there was no incidence of seroma, infection, or further complications. One patient developed a post-operative hematoma requiring evacuation and a second patient experienced distal flap necrosis and delayed wound healing. Patients reported satisfaction with the reconstruction. Conclusions: Several random patterned local flaps exist for a variety of breast defects. They can yield excellent cosmetic results, high patient satisfaction, and bolster a low rate of complications. Our case series emphasizes the utility of random patterned flaps for lateral breast oncoplastic reconstruction.

The Safe Gluteoplasty: Anatomic Landmarks to Predict the Superior and Inferior Gluteal Veins.

Objective: The increase in demand for gluteal fat grafting seen in recent years in the United States has not been met with an equal gain in knowledge of the perils of this anatomic territory. The purpose of this study was to identify anatomic landmarks that can be readily used by surgeons to identify the takeoff of the superior and inferior gluteal veins. Method: Six fresh cadaveric gluteal specimens were dissected at the University of Louisville anatomy laboratory. A question mark incision was made for exposure, followed by identification of the sciatic nerve in the proximal thigh. This was traced retrograde to the sciatic forearm. The piriformis muscle was identified dividing the foreman into superior and inferior portions, which corresponded to the takeoff of the superior and inferior gluteal vessels, respectively. The distance of the gluteal vessels from the one-third point of a line from the mid-sacrum to the greater trochanter was measured. Result: Our cadaveric dissection series demonstrated that the superior and inferior gluteal veins were on average 3.28 cm (2-5.9 cm) and 1.25 cm (0-3.5 cm) away from the point one third the distance from the mid-sacral border to the greater trochanter. Conclusion: The mid-sacrum and the trochanter of the femur are the anatomic landmarks used to identify the large gluteal vein trunks. Understanding the location and trajectory of these deep gluteal structures with use of readily identifiable landmarks may assist surgeons in avoiding inadvertent injection of fat to these veins during fat grafting.