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To compare the biomechanical characteristics of a single radially expanding all-suture anchor with an interference screw for open subpectoral long head of biceps tendon (LHBT) tenodesis.Eighteen fresh-frozen matched-pair human cadaveric humeri were used for this biomechanical study. The matched pair humeri were randomly assigned into 2 experimental biceps tenodesis groups: conventional interference screw (CIS) or all-suture suture anchor (ASSA). Open subpectoral LHBT tenodesis was then performed and biomechanical testing was performed using a servohydraulic test frame. A preload of 5 N was applied for 2 minutes before cyclic loading. Displacement was recorded at cycle 300 (D300) and cycle 500 (D500) and at ultimate failure. Data recorded included displacement, load to failure, displacement at failure. Paired t test was used for analysis.Decreased displacement was observed for the CIS group at D300 (1.67 ± 0.57 mm vs 3.35 ± 2.24 mm; P = .04), D500 (2.00 ± 0.76 mm vs 3.87 ± 2.20 mm; P = .04), and at failure (5.17 ± 3.05 mm vs 10.76 ± 2.66 mm; P.001). Load to failure was lower in CIS specimens (170 ± 24.5 N vs 217.8 ± 51.54 N; P = .02). Failure in each case was tendon pullout for all CIS specimens; in ASSA 6 specimens failed as the suture pulled through the tendon, 2 specimens failed by suture breakage. No difference in stiffness was observed between the 2 groups (CIS = 98.33 ± 22.98 N/m vs ASSA = 75.94 ± 44.83 N/m; P = .20).Our study found that open subpectoral biceps tenodesis performed with an ASSA construct results in increased load to failure as compared with CIS. However, the CIS did demonstrate decreased displacement as compared to ASSA in this cadaveric biomechanical study.ASSA and CIS at time zero provide fixation as indicated by the provider intraoperatively for LHBT tenodesis. ASSA, however, does remove less cortical bone than does CIS and therefore produces a smaller stress riser in the proximal humerus. Further testing as to the integrity of ASSA is warranted to determine the integrity of the tenodesis with cyclical loading.

Background Lisfranc ligamentous injuries are complex, and their treatment, along with the preferred method of fixation, is controversial. Implementing a flexible synthetic augmentation device (fibertape) has been described as an alternative to traditional screw fixation. This biomechanical study evaluated two fibertape devices with interference screw fixation: InternalBrace, and InternalBrace with supplementary intercuneiform stabilization. Methods The diastasis and relative angular displacement between bones were measured at three midfoot joints in the Lisfranc articulation. Measurements were obtained for the pre-injured, injured, and post-fixation stages under static loading. Specimens then underwent stepwise increases in cyclic loading performed at 1 Hz and 100 cycles, at 100 N ground reaction force intervals from 500 to 1200 N to simulate postoperative loading, and then up to 1800 N to simulate high loads. Failure of fixation was defined as diastasis greater than 2 millimeters at the second-metatarsal – medial-cuneiform joint. Results InternalBrace specimens demonstrated failures in 3 of 9 (33%) specimens at cyclic loads of 1000 N. Conversely, InternalBrace with Supplementary Limb specimens had 1 failure at 1200 N. The difference in diastasis at the second metatarsal-medial cuneiform joint was statistically significant between the two groups at higher loads of 1600N (p = 0.019) and 1800N (p = 0.029). Conclusion The use of InternalBrace for ligamentous Lisfranc injuries appears to provide a biomechanically viable alternative for withstanding early postoperative protected weight bearing. Furthermore, the use of a supplementary limb in addition to the InternalBrace fibertape fixation method appears to enhance its biomechanical efficacy.

Category: Trauma; Basic Sciences/Biologics; Midfoot/Forefoot; Sports Introduction/Purpose: Lisfranc ligamentous injuries are complex. Controversy exists regarding their treatment and preferred method of fixation. Fixation methods employing a FiberTape device and interference screw fixation have been described as an alternative to traditional screw fixation. The purpose of this biomechanical study was to evaluate two methods of fixation utilizing interference screw fixation with FiberTape augmentation in a cadaveric model. Methods: 9 paired cadaveric feet (mid tibia/fibula) were separated into two groups based on fixation method: FiberTape alone and FiberTape with supplementary limb into the middle cuneiform via anchor. At three joints of the midfoot (second metatarsal - medial cuneiform, intermediate cuneiform - medial cuneiform, second metatarsal - intermediate cuneiform), the diastasis and relative angular displacement between bones in the coronal plane were measured for static and cyclic loading. Measurements were obtained for the native (pre-injured), injured, and post-fixation in static loading. Fixed specimens then underwent stepwise increases in cyclic loading performed at 1 Hz and 100 cycles, at 100 N intervals from 500 to 1800 N ground reaction force. The Achilles tendon was also loaded to simulate postoperative weightbearing. Failure of fixation was defined as diastasis at the second metatarsal - medial cuneiform joint greater than 2 millimeters. Results: FiberTape specimens demonstrated diastasis failures of 3 of 9 (33%) specimens at cyclic loads of 1000 N. Conversely, FiberTape with supplementary limb specimens all survived past this loading magnitude, with 1 failing at supraphysiologic loads (>1200 N). The difference in diastasis at the second metatarsal-medial cuneiform joint was statistically significant between the two groups at forces of 1600N (p = 0.019) and 1800N (p = 0.029). There were no significant differences between the other joint diastases and relative angular displacements. Conclusion: The use of FiberTape for fixation of ligamentous Lisfranc injuries appears to provide a biomechanically viable alternative for withstanding early post-operative protected weightbearing. Furthermore, the use of a supplementary limb in addition to the FiberTape fixation method appears to enhance its biomechanical efficacy under cyclic loading especially at higher loads.

Category: Ankle Introduction/Purpose: In an estimated 70% of cases of Adult Acquired Flatfoot Deformity (AAFD) reconstruction, the spring ligament is elongated and/or damaged. Spring ligament reefing can be performed through several techniques including augmentation with Fibertape devices. In addition, biomechanical studies have demonstrated its safety and suggest early weight bearing may be performed. The purpose of this study is to evaluate the outcomes of early weight bearing following flatfoot reconstruction with use of InternalBrace augmentation for spring ligament reefing when performed in combination with medical displacing calcaneal osteotomy (MCO) and FDL tendon transfer. Methods: From 2016-2018, 45 patients underwent flatfoot reconstruction (MCO, FDL transfer, and gastrocnemius recession) with spring ligament reefing and augmentation with the InternalBrace device. All surgeries were performed by the senior orthopaedic surgeons (PJJ & MCA). Institutional early post-operative weight bearing protocol involves weight bearing as tolerated in a splint with crutches for two weeks, transitioning at 2 weeks to a Cam boot with 1 wedge WBAT. At 4 weeks, the patient is weaned off crutches and recommended to start therapy restricting excessive eversion and concentrating on calf strengthening, gait, and ROM. At weeks 6-8 they are weaned from the Cam boot into lace up ASO and shoe with arch support. Data were recorded at 2 weeks, 6 weeks, 12 weeks, 6 months and at yearly intervals. Outcomes and complications were documented. Results: Of the 45 cases there were no complications related to early weight bearing. Radiographic bony union rate of the MCO was 100% (45/45). Moreover, there was no loss of fixation of either the FDL transfer or spring ligament reefing with InternalBrace augmentation with early weight bearing. Lastly, radiographic evaluation noted no loss of Meary’s talo-first metatarsal angle when comparing initial postoperative radiographic to their final follow up. Additional complications in our cohort included the following: removal of painful hardware (1, 2.22%), sural neuritis (2, 4.44%), superficial cellulitis (1, 4.44%), and delayed lateral wound healing (1, 2.22%). Conclusion: Preliminary data shows that early protected weight bearing after flatfoot reconstruction and augmentation of the spring ligament with the InternalBrace device is safe and demonstrates few complications and no early loss of correction.