Cadaveric study of anterior and posterior elbow endoscopy portals for endoscopic distal biceps repair: comparative anatomy-at-risk.

PURPOSE: The purpose of this study was to describe neurovascular structures-at-risk during establishment of five portals for access to distal biceps tendon (DBT) in cubital fossa, and to establish relative safety of these portal sites for such access. We hypothesized that all five portals are safe for endoscopic DBT exploration.

METHODS

Ten fresh frozen cadaveric elbows were dissected after placement of portals at five potential sites (four anterior, one posterior). Nine neurovascular structures (CV, cephalic vein; LCN, lateral cutaneous nerve; LV, leash of vessels; RN, radial nerve; SRN, superficial radial nerve; PIN, posterior interosseous nerve; RA, radial artery; BA, brachial artery; MN, median nerve) were dissected, and their distances from portal sites were measured. Statistical analysis was performed to determine relative portal safety, and risk of injury to neurovascular structures in relation to each portal was analyzed.

RESULTS

Structures that were significantly "at risk" were RA (p = 0.006), SRN (p = 0.002), and PIN (p = 0.004). RA was significantly "at risk" of injury from portal 4 (p = 0.009). Similarly, SRN was "at risk" from portal 3 (p = 0.036), and the PIN was "at risk" from portal 2 (p = 0.003).

CONCLUSIONS

Portal 1 (parabiceps portal) was safe for all neurovascular structures, however, portals 2-4 were significantly closer to neurovascular structures. RA, SRN, and PIN were significantly "at risk" as compared to other structures amongst the portals studied. Portal 5 was relatively safe for SRN and PIN.

CLINICAL RELEVANCE: Portals 1 (parabiceps portal) and 5 (distal posterior) can be safely placed for endoscopic access to the DBT. Portal 4 (open distal anterior) may be used after careful open dissection and under direct vision. Portals 2 and 3 are not recommended for elbow endoscopy.