Biomechanical Comparison of Fiber Tape Device Versus Transarticular Screws for Ligamentous Lisfranc Injury in a Cadaveric Model.

BACKGROUND: The preferred method of fixation and surgical treatment for ligamentous Lisfranc injuries is controversial. Transarticular screws, bridge plating, fusion, and flexible fixation have been described, yet none have demonstrated superiority. Furthermore, screw fixation and plating often require secondary surgery to remove implants, leading surgeons to seek alternative fixation methods. PURPOSE: To compare transarticular screws and a fiber tape construct under a spectrum of biomechanical loads by evaluating the diastasis at 3 joints in the Lisfranc complex. STUDY DESIGN: Controlled laboratory study. METHODS: Eight matched pairs of fresh, previously frozen lower extremity cadaveric specimens were fixed with either 2 cannulated transarticular crossed screws or a fiber tape construct with a supplemental intercuneiform limb. The diastasis between bones was measured at 3 midfoot joints in the Lisfranc complex: the Lisfranc articulation, the second tarsometatarsal joint, and the intercuneiform joint. Measurements were obtained for the preinjured, injured, and fixation conditions under static loading at 50% donor body weight. Specimens then underwent cyclic loading performed at 1 Hz and 100 cycles, based on 100-N stepwise increases in ground-reaction force from 100 to 2000 N, to simulate postoperative loading from the partial weightbearing stage to high-energy activities. Failure of fixation was defined as diastasis ≥2 mm at the Lisfranc articulation (second metatarsal-medial cuneiform joint). RESULTS: There were no significant differences in diastasis detected at the Lisfranc articulation or the intercuneiform joint throughout all loading cycles between groups. All specimens endured loading up to 50% body weight + 1400 N. Up to and including this stage, there were 2 failures in the cannulated transarticular crossed-screw group and none in the fiber tape group. CONCLUSION: The fiber tape construct with a supplemental intercuneiform limb, which does not require later removal, may provide comparable biomechanical stability to cannulated transarticular crossed screws, even at higher loads. CLINICAL RELEVANCE: Ligamentous Lisfranc injuries are common among athletes. Therefore, biomechanical evaluations are necessary to determine stable constructs that can limit the time to return to play. This study compares the biomechanical stability of 2 methods of fixation for ligamentous injury through a wide spectrum of loading, including those experienced by athletes.

Comparing the Efficacy of True-Volume Analysis Using Magnetic Resonance Imaging With Computerized Tomography and Conventional Methods of Evaluation in Cystic Osteochondral Lesions of the Talus: A Pilot Study.

Background: Osteochondral lesions of the talus (OLT) often require advanced imaging if they prove to be refractory to preliminary microfracture. Orthopedic surgeons may misinterpret the size and morphology of the OLT when evaluating through conventional methods. The purpose of this study was to evaluate MRI as a modality for calculating true-volumes and compare its utility to that of CT true-volume and conventional methods of measuring lesion size. METHODS: With IRB approval, an institutional radiology database was queried for patients with cystic OLT that had undergone and failed microfracture and had compatible CT and MR scans between 2011 and 2016. Five lesions, previously analyzed and described in the literature using CT true-volume, were selected. 10 orthopedic surgeons independently estimated the volume of these 5 OLT via standard MRI. Next, 3D reconstructions were created and morphometric true-volume (MTV) analysis measurements of each OLT were generated. The percent change in volumes from CT and MR was compared based upon MTVs determined from 3D reconstructive analysis. RESULTS: The volume calculated using conventional methods in CT and MR scans grossly overestimated the size by of the OLT by 285-864% and 56-374% respectively when compared to 3D true-volume analysis of those CT and MR scans. CONCLUSIONS: This study demonstrates that true-volume is more accurate for calculating lesion size than conventional methods. Additionally, when comparing MRI and CT, thin slice CT true-volume is superior to MRI true-volume. True-volume calculation improves accuracy with CT and MRI and should be recommended for use in revision OLT cases.Levels of Evidence: Level III: Case control study.

Approach to the treatment of primary anterior shoulder dislocation: A review.

Glenohumeral joint dislocation is common among younger, active patients. Anterior dislocation is the most common direction of instability following a traumatic event. Due to a high rate of recurrence following primary traumatic anterior shoulder dislocation, an evidence-based approach is necessary to determine the best treatment regime for a patient presenting with this problem. A history, physical examination, and radiographic imaging can help guide treatment recommendations by determining the extent of soft tissue damage following dislocation. Controversies in the treatment of the first-time dislocator include the length and position of immobilization following dislocation, and the role of initial surgical stabilization. This article outlines the treatment options for the first-time glenohumeral dislocator, with an emphasis on the available evidence in the literature. Where applicable, the criteria known as the Strength of Recommendation Taxonomy were used to summarize the strength of evidence available for recommendations.