Dataset Information

Biomechanical Comparison of First Tarsometatarsal Arthrodesis Constructs Over Prolonged Cyclic Testing.

ABSTRACT:

Background

Traditionally, a lengthy period of nonweightbearing is required following arthrodesis of the first tarsometatarsal (TMT) joint in order to provide a stable healing environment for the bones. The goal of this research was to determine the resistance to plantar gapping of 2 locked intramedullary devices and a medial plate with crossing screw, all specifically designed for hallux valgus correction, and compare them to traditional 2-crossing screw fixation under a cyclic testing protocol. We hypothesized the locked intramedullary devices and the medial plate with crossing screw would better resist plantar gapping.

Methods

Forty cadaver specimens received 1 of 4 operative treatments: a locked intramedullary device with 2 points of fixation in the cuneiform, a locked intramedullary device with 1 point of fixation in the cuneiform, a medial plate with crossing screw, or 2 crossing screws. We applied dorsiflexion bending forces to the first TMT joint using a cadaveric fatigue model for 20 000 cycles. The plantar gap between the metatarsal and cuneiform was measured at the beginning and end of cyclic testing. Thirty-six specimens were included in the final data set.

Results

Both locked intramedullary device groups and the medial plate with crossing screw group exhibited significantly less gap widening compared to the 2-crossing screw group (vs 3-hole intramedullary device, P = .014; vs 4-hole intramedullary device, P = .010; and vs medial plate with crossing screw, P = .044). The intramedullary device groups were the most stable during the cyclic fatigue test, exhibiting the smallest gap widening. The medial plate with crossing screw fixation was also more stable than crossing screws in the cyclic fatigue model.

Conclusions

The locked intramedullary devices and medial plate with crossing screw resisted plantar gapping better than 2 crossing screws when used for first TMT arthrodesis.

Clinical relevance

These results indicate that locked intramedullary devices and medial plates with crossing screws may promote superior bone healing and may better tolerate early weightbearing compared with 2 crossing screws.

SUBMITTER: Prieto-Diaz C

PROVIDER: S-EPMC8697146 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundUnstable Lisfranc injuries are best treated with anatomic reduction and stable fixation. There are controversies regarding which type of stabilization is best. In the present study, we compared primary arthrodesis of the first tarsometatarsal (TMT) joint to temporary bridge plating in unstable Lisfranc injuries.MethodsForty-eight patients with Lisfranc injuries were included and followed for 2 years. Twenty-four patients were randomized to primary arthrodesis (PA) of the medial 3 TMT joints, whereas 24 patients were randomized to temporary bridge plate (BP) over the first TMT joint and primary arthrodesis of the second and third TMT joints. The main outcome parameter was the American Orthopaedic Foot & Ankle Society (AOFAS) midfoot scale and the secondary outcome parameters were the 36-Item Short Form Health Survey (SF-36) and visual analog scale for pain (VAS pain). Computed tomography (CT) scans pre- and postoperatively were obtained. Radiographs were obtained at follow-ups. Pedobarographic examination was performed at the 2-year follow-up. Twenty-two of 24 patients in the PA and 23/24 in the BP group completed the 2-year follow-up.ResultsThe mean AOFAS midfoot score 2 years postoperatively was 89 (SD 9) in the PA group and 85 (SD 15) in the BP group (P = .32). There were no significant differences between the groups with regard to SF-36 or VAS pain scores. The alignment of the first metatarsal was better in the BP group than in the PA group measured by the anteroposterior Meary angle (P = .04). The PA group had a reduced peak pressure under the fifth metatarsal (P = .047). In the BP group, 11/24 patients had radiologic signs of osteoarthritis in the first TMT joint.ConclusionBoth treatment groups had good outcome scores. The first metatarsal was better aligned in the BP group; however, there was a high incidence of radiographic osteoarthritis in this group.Level of evidenceTherapeutic level I, prospective randomized controlled study.

Project description:BackgroundFirst tarsometatarsal joint (TMT-1) hypermobility might cause hallux valgus deformity (HV), and recurrence following surgical correction. Anatomic findings, indicating tibialis anterior tendon (TAT) involvement in TMT‑1 stabilization, led to the development of cross-glide test allowing clinical TMT‑1 stability testing. Cross-glide test function was evaluated in anatomical specimens and in the clinical setting, compared to simulated weight-bearing computer tomography (CT) analysis.MethodsCross-glide test was evaluated in 6 healthy lower leg specimens before and after TAT transection. Clinical testing was performed prospectively in 36 feet (6 controls, 21 HV, 9 recurrent HV); consecutive weight-bearing CT analysis was performed. Results from clinical testing were compared to CT analysis.ResultsTMT‑1 instability significantly increased in anatomic specimens following TAT transection (p = 0.009). In the clinical setting, all healthy feet were cross-glide test negative, 62% of HV cases and all recurrent HV feet were positive. In the CT analysis- Compared to controls the HV cases revealed significantly increased MT‑1 internal rotation (p = 0.003) and decreased dorsal angle (p = 0.002), considered as collapsing forefoot signs; HV recurrent cases revealed similar results. Positive cross-glide tested cases revealed increased MT‑1 internal rotation values (p < 0.001) and dorsal angle values (p < 0.001) in CT analysis. Strikingly, cross-glide test positive HV cases revealed significantly increased internal TMT‑1 rotation (p = 0.043) in CT analysis, and HV and IMT (intermetatarsal) angle were significantly higher (p = 0.005, p = 0.006). 15 HV recurrence cases, treated with TMT‑1 arthrodesis, revealed no recurrence during follow-up.ConclusionCross-glide test allows reliable clinical TMT‑1 instability testing, via TAT tension, and is less laborious than CT analysis. We recommend TMT‑1 arthrodesis in cases with instability in clinical testing, to avoid HV recurrence.

Project description:To compare the static and dynamic mechanical properties of a modified crossed cannulated screw (CS) configuration, the inverted triangle (IT) cannulated screw configuration, and a compression hip screw (CHS) with derotation screw in Pauwels type III femoral neck fractures.Thirty synthetic femora were divided into 3 groups, and vertical femoral neck osteotomies were made. Ten osteotomized femora were fixed with a CS configuration, 10 were fixed with 3 parallel screws in an IT configuration, and the remaining 10 osteotomized femora were fixed with a CHS construct. All groups were tested using a cyclic (up to 15,000 load cycles) axial loading protocol, and survivors were statically loaded to failure. Cycles to failure, load to failure, and stiffness were calculated. The Kaplan-Meier method was used to estimate survival functions and were compared among fixation methods. The relationship between construct structural properties (maximum load and stiffness) and treatment were assessed using general linear modeling.All CHS fixation constructs survived the 15,000 cycle loading protocol. They endured longer (P = 0.034) than the CS fixation constructs (mean failure 13,332 cycles), but were not different from IT fixation constructs (mean failure 13,592 cycles). Maximum loads to failure for CS (3870 N) and IT (3756 N) fixation constructs were not different, but were less (P < 0.0001) than the maximum loads to failure for the CHS fixation constructs (5654 N). These findings parallel the results of the axial stiffness measurements: CS fixation constructs (663.01 N/mm) were not stiffer than IT fixation constructs (620.0 N/mm), but were less (P = 0.0005) than the axial stiffness of the CHS fixation constructs (1241.86 N/mm).The biomechanical performance of the CHS fixation method was superior to both the CS fixation method and the IT fixation method using a synthetic femoral model and this test protocol. Biomechanical performance of the latter 2 groups was indistinguishable. We recommend the use of CHS with the derotational screw construct for Pauwels III femoral neck fractures whenever possible.