SLR - August 2019 - Vikram A. Bala
Reference: Bansal, Ankit et al. "Ligamentous Lisfranc Injury: A Biomechanical Comparison of Dorsal Plate Fixation and Transarticular Screws ". Journal of Orthopaedic Trauma, vol 33, no. 7, 2019, pp. e270-e275. Ovid Technologies (Wolters Kluwer Health), doi:10.1097/bot.0000000000001466. Accessed 26 June 2019.Scientific Literature Review
Reviewed By: Vikram A. Bala, DPM
Residency Program: University of Florida Health – Jacksonville, FL
Podiatric Relevance: Patient outcomes after purely ligamentous injuries to the Lisfranc joint complex are far inferior to those with combined osseous injuries and optimal fixation technique for these types of injuries remains controversial. This biomechanical study compares a dorsal locking plate construct to transarticular cannulated screws by measuring dorsal and plantar joint diastasis before and after a simulated loading trial. A unique protocol was implemented to determine the durability of two fixation constructs after simulated partial weight-bearing.
Methods: Eleven cadaveric matched pairs were assigned to either the dorsal plate or transarticular screw fixation group. A four-hole dorsal locking plate was used in the first group to fixate medial and intermediate cuneiforms to the bases of metatarsals one and two, using bi-cortical screws. In the second group, 3.75 mm fully-threaded, cannulated screws were used transarticularly, spanning the Lisfranc and intercuneiform joints. Reflective markers were placed on the medial cuneiform and the second metatarsal base to measure Lisfranc joint diastasis using three cameras to record the location of the triad markers in 3-dimensions. Four states of the Lisfranc joint were used to assess fixation methods: (1) Lisfranc and intercunieform ligaments intact, (2) Lisfranc and intercuneiform ligaments cut (3) fixated Lisfranc joint using dorsal plate or transarticular screw constructs, and finally (4) Lisfranc ligament fixated after 10,000 343N-loaded cycles to simulate partial weight-bearing. Plantar diastasis was measured in each state and statistical analysis was performed between the two fixation groups.
Results: Dorsal plate fixation significantly reduced dorsal diastasis relative to the transected Lisfranc and intercuneiform ligaments; but did not improve plantar diastasis. Transarticular fixation had significant reductions in dorsal and plantar diastasis when compared to the transected ligament state. Dorsal plate fixation and plantar diastasis distance was noted to be greater than transarticular screw fixation both before and after simulated weight-bearing. Cyclic loading had no effect on either fixation technique with the exception of intermetatarsal distance, where dorsal plating performed better than transarticular screws. Dorsal plate fixation reduced intermetatarsal diastasis to levels significantly less than the intact ligament, transected ligament and screw fixation states. Screw fixation, however, only maintained intermetatarsal gapping prior to cyclical loading.
Conclusions: Between the two fixation groups, there was greater improvement in plantar gapping with the transarticular screw fixation versus the dorsal locking plate. This finding lends credence to the principles of fracture fixation, as transarticular fixation acts almost as an intramedullary fixation and holds tarsometatarsal joint positions more evenly versus dorsal compression plating. In terms of intermetatarsal gapping, the dorsal plate fixation maintained less diastasis than the intact ligament, transected ligament and screw fixated models. This finding may prove useful in determining how to manage a purely ligamentous tarsometatarsal joint injury. Neither fixation group was noted to have a significant increase in intermetatarsal diastasis after simulated partial weight-bearing, thus suggesting partial weight-bearing immediately post-op may be a feasible option. In summary, both transarticular screw and dorsal locking plate fixation prevented dorsal diastasis of the Lisfranc joint, but screw fixation proved to prevent plantar joint diastasis more effectively.