Osteochondral lesions of the talus remain a challenging pathologic entity facing orthopaedic foot and ankle surgeons. Although multiple treatment options exist, there is limited evidence supporting ...one technique over another. The ultimate goal of surgical intervention is to achieve lesion infill with tissue properties that best mimic those of hyaline articular cartilage. Restoring the anatomic surface of the talus may provide long-term clinical success and improve function. Augmentation of bone marrow stimulation with extracellular matrix cartilage allograft aims to achieve this goal.
Purpose
Tibial insert conformity in total knee arthroplasty (TKA) is of interest due to the potential effect on tibiofemoral kinematics. This study determined differences in anterior–posterior ...movements of the femoral condyles, pivot locations, and internal tibial rotation in different arcs of flexion for two implants with different insert conformities in kinematically aligned TKA.
Methods
Twenty-five patients treated with a medial and lateral low-conforming, posterior cruciate ligament (PCL) retaining (LC CR) implant followed by a medial ball-in-socket and flat, lateral PCL sacrificing (B-in-S CS) implant in the contralateral knee underwent single-plane fluoroscopy during a deep knee bend. Analysis following 3D-to-2D image registration determined tibiofemoral kinematics and patients completed validated outcome scores for both knees.
Results
The mean follow-up of 1.6 ± 0.4 years for the knee with the B-in-S CS implant was shorter than the 2.7 ± 1.2 years for the LC CR implant. From 0º to 30º of flexion, a medial pivot occurred with the tibia rotating internally approximately 5º with both implants. From 30º to 90º, the pivot remained medial and internal rotation increased to 10º with the B-in-S CS implant. In contrast, neither femoral condyle moved more than 1 mm with the LC CR implant from 30º to 60º, but from 60º to 90º degrees, a lateral pivot occurred and internal rotation increased. Internal rotation of the tibia on the femur from 0° to maximum flexion occurred about a medial pivot similar to the native knee for the B-in-S CS implant and was 4.5° greater than that of the LC CR implant (10.4° vs 5.9°). There was no difference in the median patient-reported outcome scores between implant designs.
Conclusions
Tibial insert conformity is a primary determinant of a medial or lateral pivot during a deep knee bend. One explanation for the transition from a medial to lateral pivot between 30º and 60º with the LC CR implant is the chock-block effect of the insert’s posterolateral upslope which impedes posterior movement of the lateral femoral condyle. Because there is no posterolateral upslope in the insert of the B-in-S CS implant, the tibia pivots medially throughout flexion similar to the native knee.
Level of evidence
Level III.
To determine the effect of simulated radioscapholunate fusion with distal scaphoid excision (RSLF+DSE), 4-corner fusion with scaphoidectomy (4-CF), and proximal row carpectomy (PRC) on the wrist’s ...range of motion (ROM), contact pressure, and contact force in a cadaveric model.
Ten freshly frozen cadaveric wrists were tested under 4 sequential conditions: native wrist, RSLF+DSE, 4-CF, and PRC. The simulated fusions were performed using two 1.6-mm Kirschner wires. The ROM in the flexion-extension and radioulnar deviation planes was evaluated. Contact area, contact pressure, and contact force were measured at the scaphocapitolunate joint for the RSLF+DSE simulation and radiocarpal joint for the 4-CF and PRC simulations. Mechanical testing was performed using a 35-N uniaxial load and pressure-sensitive film.
The RSLF+DSE and 4-CF groups had a decreased wrist arc ROM compared with the native wrist. The PRC group had a greater wrist arc ROM compared with the RSLF+DSE and 4-CF groups, but compared to the native wrist, it demonstrated a mildly decreased wrist arc ROM. The carpal pressure and contact force were significantly increased in the RSLF+DSE, 4-CF, and PRC groups compared with those in the native wrist. The RSLF+DSE group had the smallest increase in the carpal pressure and contact force, whereas the PRC group had the greatest increase.
Our study validates previous findings that PRC is motion-conserving but has the greatest contact force, whereas RSLF-DSE and 4-CF may cause a decrease in the ROM but have lower contact forces.
Understanding the underlying native wrist biomechanics and alterations following different surgical treatments may assist hand surgeons in their clinical decision making for the treatment of stage II scapholunate advanced collapse.
People who sustain joint injuries such as anterior cruciate ligament (ACL) rupture often develop post-traumatic osteoarthritis (PTOA). In human patients, ACL injuries are often treated with ACL ...reconstruction. However, it is still unclear how effective joint restabilization is for reducing the progression of PTOA. The goal of this study was to determine how surgical restabilization of a mouse knee joint following non-invasive ACL injury affects PTOA progression.
In this study, 187 mice were subjected to non-invasive ACL injury or no injury. After injury, mice underwent restabilization surgery, sham surgery, or no surgery. Mice were then euthanized on day 14 or day 49 after injury/surgery. Functional analyses were performed at multiple time points to assess voluntary movement, gait, and pain. Knees were analyzed ex vivo with micro-computed tomography, RT-PCR, and whole-joint histology to assess articular cartilage degeneration, synovitis, and osteophyte formation.
Both ACL injury and surgery resulted in loss of epiphyseal trabecular bone (−27–32%) and reduced voluntary movement at early time points. Joint restabilization successfully lowered OA score (−78% relative to injured at day 14, p < 0.0001), and synovitis scores (−37% relative to injured at day 14, p = 0.042), and diminished the formation of chondrophytes/osteophytes (−97% relative to injured at day 14, p < 0.001, −78% at day 49, p < 0.001).
This study confirmed that surgical knee restabilization was effective at reducing articular cartilage degeneration and diminishing chondrophyte/osteophyte formation after ACL injury in mice, suggesting that these processes are largely driven by joint instability in this mouse model. However, restabilization was not able to mitigate the early inflammatory response and the loss of epiphyseal trabecular bone, indicating that these processes are independent of joint instability.
Extensor tendon entrapment in the presence of distal radius fractures is a known but relatively uncommon complication. Single tendon or entire compartment entrapment has been described through the ...literature in youths and adults. However, these findings generally are limited to a certain age demographic or are found on advanced imaging but are unable to be confirmed intraoperatively. We describe to our knowledge the first known description of second extensor compartment entrapment in an adult seen on computerized tomography scan and confirmed intraoperatively.
We present a case of dysplasia epiphysealis hemimelica (DEH) involving the posteromedial distal femur in a 4-year-old girl. The patient underwent lesion resection with internal fixation of the ...articular cartilage followed by autologous chondrocyte implantation (ACI) to restore the articular surface and epiphysis. At the 7-year follow-up, the patient had no pain or difficulty with participation in sports. Advanced imaging showed a stable articular surface with evidence of durable cartilage integration.
DEH is a rare disease often treated by resection. In cases where the articular surface of the knee is involved, we have demonstrated that augmentation with ACI can be an effective treatment option.
Despite guidelines recommending postfracture bone health workup, multiple studies have shown that evaluation and treatment of osteoporosis has not been consistently implemented after fragility ...fractures. The primary aim of this study was to evaluate rates of osteoporosis evaluation and treatment in adult patients after low-energy thoracolumbar vertebral compression fractures (VCFs).
We retrospectively reviewed all patients ≥60 years old presenting to a single academic trauma center with acute thoracolumbar VCFs after a ground-level fall from 2016 to 2020 . Rates of osteoporosis screening with dual-energy x-ray absorptiometry and initiation of pharmaceutical treatment were recorded at four time points: before the date of injury, during index hospitalization, at first primary care provider follow-up, and at final primary care provider follow-up. Rates of subsequent falls and secondary fragility fractures were recorded. One-year mortality and overall mortality were also calculated.
Fifty-two patients with a mean age of 83 years presenting with thoracic and/or lumbar fractures after a ground-level fall were included. At a mean final follow-up of 502 days, only 10 patients (19.2%) received pharmacologic therapy for osteoporosis and only 6 (11.5%) underwent postinjury dual-energy x-ray absorptiometry evaluation. Twenty-five patients (48%) had at least one subsequent fall at a mean of 164 days from the initial date of injury. Eleven patients with subsequent falls sustained an additional fragility fracture because of the fall, including six operative injuries. One-year mortality among the 52 patients was 26.9%, and the overall mortality rate was 44.2% at the final follow-up.
Osteoporosis remains a major public health issue that markedly affects quality of life and healthcare costs. Our study demonstrates the additional need for improved osteoporosis workup and intervention among patients who have sustained VCFs. We hope that our study helps raise awareness for improved osteoporosis evaluation and treatment among spine surgeons and all medical professionals treating patients with fragility fractures.
Retrospective Case Series, Level IV Evidence.
Within the past two decades polylactic-co-glycolic acid (PLGA) has gained considerable attention as a biocompatible and biodegradable polymer that is suitable for tissue engineering and regenerative ...medicine. In this present study, we have investigated the potential of PLGA, collagen I (ColI), and polyurethane (PU) scaffolds for ligament tissue regeneration. Two different ratios of PLGA (50:50 and 85:15) were used to determine the effects on mechanical tensile properties and cell adhesion. The Young's modulus, tensile stress at yield, and ultimate tensile strain of PLGA(50:50)-ColI-PU scaffolds demonstrated similar tensile properties to that of ligaments found in the knee. Whereas, scaffolds composed of PLGA(85:15)-ColI-PU had lower tensile properties than that of ligaments. Furthermore, we investigated the effect of fiber orientation on mechanical properties and our results indicate that aligned fiber scaffolds demonstrate higher tensile properties than scaffolds with random fiber orientation. Also, human fibroblasts attached and proliferated with no need for additional surface modifications to the presented electrospun scaffolds in both categories. Collectively, our investigation demonstrates the effectiveness of electrospun PLGA scaffolds as a suitable candidate for regenerative medicine, capable of being manipulated and combined with other polymers to create three-dimensional microenvironments with adjustable tensile properties to mimic native tissues.
Abstract While stem cell niches in vivo are complex three-dimensional (3D) microenvironments, the relationship between the dimensionality of the niche to its function is unknown. We have created a 3D ...microenvironment through electrospinning to study the impact of geometry and different extracellular proteins on the development of cardiac progenitor cells (Flk-1+ ) from resident stem cells and their differentiation into functional cardiovascular cells. We have investigated the effect of collagen IV, fibronectin, laminin and vitronectin on the adhesion and proliferation of murine ES cells as well as the effects of these proteins on the number of Flk-1+ cells cultured in 2D conditions compared to 3D system in a feeder free condition. We found that the number of Flk-1+ cells was significantly higher in 3D scaffolds coated with laminin or vitronectin compared to colIV-coated scaffolds. Our results show the importance of defined culture systems in vitro for studying the guided differentiation of pluripotent embryonic stem cells in the field of cardiovascular tissue engineering and regenerative medicine.
Category:
Ankle Arthritis; Hindfoot
Introduction/Purpose:
Tibiotalocalcaneal (TTC) arthrodesis is a common surgical technique used in the treatment of various hindfoot pathologies. Large osseus ...defects are particularly challenging with a high rate of graft collapse and nonunion when using autograft or allograft. Porous tantalum has emerged as a favorable osteoconductive material to address sizeable hindfoot defects. The purpose of this study was to review the radiographic outcomes and complications associated with tantalum spacer augmentation in hindfoot arthrodesis.
Methods:
A retrospective review was performed of all patients who underwent a hindfoot arthrodesis augmented with a metal spacer (Trabecular MetalTM) from 2012 to 2020 at a single institution. Patients endif–>18 years of age who had a large, hindfoot osseus defect were included in the study. Surgeries were performed by two fellowship-trained foot and ankle orthopaedic surgeons. The primary outcomes assessed were presence of radiographic union, post-operative complications, and return to the operating room.
Results:
Fourteen patients were identified who underwent hindfoot arthrodesis with the use of a Trabecular MetalTM augment. Two of the 14 patients were lost to follow-up resulting in a total of 12 patients with an average age of 59 years (range, 42 - 74). The average length of follow-up was 26 months (range, 4 - 56). Four patients had plain radiographs at final follow-up compared to 7 patients who had CT scans performed. Nine patients underwent TTC fusion with a retrograde intramedullary nail (MedShape DynaNail) and three patients underwent isolated subtalar (ST) fusion. Ten of 12 fusions were augmented using reamer irrigator aspirator (RIA) autograft and two patients received autograft from either the tibia or fibula. Of the 12 patients, 10 achieved radiographic evidence of union for a union rate of 83%. There were three patients who required reoperations: one hypertrophic nonunion, one surgical site infection, and one symptomatic hardware.
Conclusion:
Tantalum provides a great structural option for patients undergoing TTC or ST fusion in the setting of large hindfoot bony defects. This method combined with the use of autograft and adequate biomechanical stabilization can produce reliable results. Functional outcomes are needed to capture the utility of this technique in attaining longterm clinical results.
PDF
