Abstract
Research Type:
Level 4 – Case series
Introduction/Purpose:
Isolated or combined minimally invasive surgery (MIS) percutaneous arthrodesis of the 1st tarsometatarsal (TMT) and naviculocuneiform (NC) joints have been proven to be successful in realigning and stabilizing the medial column in the treatment of hallux valgus with/without flatfoot deformity or midfoot arthritis. It has the advantage of reduced postoperative pain, less wound complications and fast recovery. The objective of this cadaveric study was to introduce safe and effective portals for MIS 1st TMT arthrodesis and NC arthrodesis with respect to nearby anatomical structures.
Methods:
MIS 1st TMT and NC arthrodesis procedures were performed on 20 fresh-frozen cadaveric feet. Two portals were developed for the 1st TMT arthrodesis: dorsal and plantar medial. And two portals were introduced for the NC arthrodesis: dorsal and medial. Thorough joint preparation was conducted using a Shannon burr under fluoroscopy. Skin on the dorsal and medial side of the foot was removed, followed by sequential dissection to examine the intactness of the surrounding key anatomical structures: great saphenous vein (GSV), medial and lateral dorsal cutaneous branches of the superficial peroneal nerve (MDCB, LDCB), dorsal neurovascular bundle (DNVB), anterior tibial tendon (ATT), extensor hallucis longus (EHL), extensor digitorum longus tendon (EDL) and extensor hallucis brevis muscle (EHBM). The distance between each portal and those anatomical structures, and damages was measured. The remaining soft tissue envelope over the joints was completely removed to allow direct examination of the effectiveness of the portals.
Results:
Safety and effectiveness of the portals for the 1st TMT arthrodesis: among the 20 cadaveric feet, there were 0 tendon ruptures, 0 nerve injuries, and 0 DNVB injuries. 20 of the specimens suffered mild abrasion of the ATT insertion at the plantar medial portal. Complete access to the 1st TMT joint with full cartilage removal was achieved in 19/20 feet. For the NC joint: there were 0 nerve injurie, 0 DNVB injurie, 0 tendon injurie, 20 mild abrasions to the extensor hallux brevis muscle (EHBM) at the dorsal portal. The distance between the dorsal portal and the DNVB was 3.83 mm (+/- 2.13). Complete access to all three NC joint facets with full cartilage removal was achieved in 18/20 feet.
Conclusion:
The portals introduced in this study for MIS 1st TMT and NC arthrodesis can provide safe access and effective preparation of both joints. These portals also offer the potential for combined MIS and arthroscopic evaluation of the joints, to further enhance the precision of the surgery.
