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The 3-dimensional nature of adult acquired flatfoot deformity can be challenging to characterize using radiographs. We tested the hypothesis that measurements on weight-bearing (WB) cone-beam computed tomography (CT) images were more useful for demonstrating the severity of the deformity than non-weight-bearing (NWB) measurements.We prospectively enrolled 12 men and 8 women (mean age, 52 years; range, 20 to 88 years) with flexible adult acquired flatfoot deformity. The subjects underwent cone-beam CT while standing (WB) and seated (NWB), and images were assessed in the sagittal, coronal, and axial planes by 3 independent observers who performed multiple measurements. Intraobserver and interobserver reliabilities were assessed with the Pearson or Spearman correlation and the intraclass correlation coefficient (ICC), respectively. Measurements were compared using paired Student t tests or Wilcoxon rank-sum tests. P0.05 was considered significant.We found that overall the measurements had substantial intraobserver and interobserver reliability on both the NWB images (mean ICC, 0.80; range, 0.49 to 0.99) and the WB images (mean ICC, 0.81; range, 0.39 to 0.99). Eighteen of 19 measurements differed between WB and NWB cone-beam CT images, with more pronounced deformities on the WB images. The most reliable measurements, based on intraobserver and interobserver reliabilities and the difference between WB and NWB images, were the medial cuneiform-to-floor distance, which averaged 29 mm (95% confidence interval [CI] = 28 to 31 mm) on the NWB images and 18 mm (95% CI = 17 to 19 mm) on the WB images, and the forefoot arch angle (mean, 13° [95% CI = 12° to 15°] and 3.0° [95% CI = 1.4° to 4.6°], respectively) in the coronal view and the cuboid-to-floor distance (mean, 22 mm [95% CI = 21 to 23 mm] and 17 mm [95% CI = 16 to 18 mm], respectively) and the navicular-to-floor distance (mean, 38 mm [95% CI = 36 to 40 mm] and 23 mm [95% CI = 22 to 25 mm], respectively) in the sagittal view.Measurements analogous to traditional radiographic parameters of adult acquired flatfoot deformity are obtainable using high-resolution cone-beam CT. Compared with NWB images, WB images better demonstrated the severity of osseous derangement in patients with flexible adult acquired flatfoot deformity.Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Category: Basic Sciences/Biologics Introduction/Purpose: Diabetic foot infection (DFI), including skin infection and osteomyelitis, is a severe complication of late- stage diabetes. Mesenchymal stem cells (MSCs) facilitate bacterial clearance. In bacterial infection, MSCs, via paracrine mediators, regulate the host cell metabolism and inflammatory response. Particularly, MSCs augment the antibacterial function of neutrophils. It is generally believed that hyperglycemia in diabetes is toxic to MSCs/progenitors and detrimental to their regenerative function. It is unknown, however, whether the antibacterial function of MSCs is compromised in diabetes. Methods: Bone marrow samples from 6 diabetic and 4 non-diabetic patients (approved by IRB) were used for MSC isolation. 1. MSCs from both diabetic and non-diabetic patients were treated with lipopolysaccharides (LPS), a bacterial wall component, for 6 hours. The tissue culture media were collected as conditioned medium. E. coli from a single colony were cultured with addition of the conditioned medium generated by either diabetic or non-diabetic MSCs and inoculated on LB-agar plates overnight. Bacterial colonies were counted. 2. Human macrophages were isolated from umbilical cord blood and co-cultured with either diabetic or non-diabetic MSCs, in a trans-well system, for 24 hours. The macrophages were then cultured with heat-inactivated E. coli for one hour. After extensive washing, macrophage and bacteria were stained with Pappenheim method. Bacterial phagocytosis of macrophages, after co- cultured with diabetic or non-diabetic MSCs, was assessed under a microscope. Results: There was no statistical difference in the number of E. coli colonies when regular medium produced by diabetic and non- diabetic MSCs was added into the bacterial culture. When the diabetic and non-diabetic MSCs were treated with LPS and the conditioned medium was collected and added into bacterial cultures, E. coli colonies increased in the diabetic group, about 3 fold, as compared with the non-diabetic group (p < 0.05). Macrophages were counted in defined areas of the Petri dishes and designated as infected or uninfected, according to the presentation of bacterial bodies or not. While the infection rate of macrophages co-cultured with non-diabetic MSCs was 85% (±5.5%), it was 70% (±6.6%) when macrophages were co-cultured with diabetic MSCs (p = 0.006). Conclusion: MSCs-produced paracrine factors suppressed the growth of E. coli but diabetic and non-diabetic MSCs had no difference in such a function. Activation with LPS did not augment the non-diabetic MSCs but weakened diabetic MSCs in suppression of bacterial growth. MSCs regulate macrophages in bacterial phagocytosis. Diabetic MSCs, however, had a limited role in regulation of macrophages. This study demonstrated that MSCs in diabetic patients are compromised in anti-bacterial infection. The results not only deepen the understanding of bacterial infection in diabetes but also open up new strategy to control bacterial infection in diabetic patients.

Category: Basic Sciences/Biologics Introduction/Purpose: Tendinopathy causes pain and dysfunction. Conservative treatments of tendinopathy include physical therapy, rest, training modification, splintage, taping, cryotherapy, electrotherapy, shock wave therapy, hyperthermia and local injections. These therapies, however, do not target specific pathology and are unable to modify the progression of the disease. The pathology of tendinopathy is considered as a continuum of tendon degeneration but the precise molecular pathology of tendinopathy is still lacking. Accumulation of advanced glycation end-products (AGEs) happens during connective tissue aging and affects tendon viscoelasticity. Estrogen, which functions via estrogen receptor (ER), is essential for metabolism and plays a role in tendon health and aging. This preliminary study investigated the expression of AGEs and ER in tendinopathy. Methods: This study included six patients with posterior tibial tendon (PTT) tendinopathy (age from 20 to 72 years, 5 male and 1 female). Normal flexor digitorum longus (FDL) tendon samples were collected from three donors (female, age from 42 to 51 years, approved by IRB). Tissue samples of tendinopathy and normal tendon were fixed with 4% paraformaldehyde and sectioned with a cryostat. Picrosirius Red stain was used for collagen structure. Immunohistochemistry of AGEs, AGEs receptor (RAGEs) and ER was performed on separate tissue sections. The primary antibody of AGEs, RAGEs and ER was separately applied onto the tissue sections for one hour. The proper secondary antibody that conjugated with peroxidase was applied and incubated for 30 min, followed by the application of 3,3’-diaminobenzidine for chromogenic detection of protein expression. Cell nuclei were conterstained with hematoxylin. Tissue sections omitted application of primary antibody were used as negative controls. Results: Tissue sections stained with Picosirius Red were examined under a circular polarizing microscope. Tendinopathy of PTT was confirmed by a disorderly organized collagen network and highly heterogeneous collagen contents. Cellularity was greatly increased in the pathological region. ER was uniformly expressed by tenocytes in the PTT pathologic tissues. The ER-positive cells were particularly located in areas featured disorganized collagen fibers and dense cellularity. After antigen retrieval with sodium citrate buffer, enhanced expression of AGEs was detected in the tendon tissue of PTT. RAGEs was expressed by a few tenocytes in the pathological region of PTT sections but not in normal FDL sections. Conclusion: The long-term goal of this study is to identify key molecules involved in tendinopathy, for developing disease- modifying therapies. This preliminary study revealed the expression of several molecules, which are associated with connective tissue aging process, in tendinopathy. The accumulation of AGEs and increased expression of ER in the pathological tendon add more molecular features to tendinopathy. Future study will focus on the pathological role of these molecules in regulation of tenocytes.

Category: Hindfoot Introduction/Purpose: Adult acquired flatfoot deformity (AAFD) represents a biomechanical derangement involving the three- dimensional (3D) midfoot and hindfoot osseous complex, and can be challenging to optimally characterize using conventional two- dimensional (2D) plain radiographs. Weightbearing (WB) ConeBeam CT (CBCT) can better demonstrate the deformity of the 3D structures during WB. Therefore, we compared validated AAFD measurements between WB conventional radiographs and WB CBCT images. Methods: In this prospective, IRB approved and HIPAA compliant study, 20 patients (20 feet, 15 right and 5 left) with clinical diagnosis of flexible AAFD were included, 12 males and 8 females, with a mean age of 52.2 years (range, 20 to 88 years of age), and average BMI of 30.35 kg/m2 (range, 19.00 to 46.09 kg/m2). Involved feet underwent standing (WB) anteroposterior (AP) and lateral radiographs, and were also scanned by WB CBCTs. Both imaging modalities were assessed with traditional AAFD measurements obtained at sagittal (lateral view on radiograph) and axial (anteroposterior view on radiograph) planes using predefined anatomical landmarks, by two independent and blinded foot and ankle fellowship-trained observers. Intra- and Inter- observer reliabilities for both imaging modalities were calculated using Pearson correlation. WB radiograph and WB CBCT measurements were compared by T-Test of the means. P- values < 0.05 were considered significant. Results: There was good to excellent intra and inter-observer agreements for most of the measurements on both radiographs and WB CBCT images, with slightly better results favoring WBCT measurements. When comparing WB radiographs and WB CBCT images, we found significant differences in the mean values for some of the measurements, including: talus-first metatarsal angle in the sagittal plane (11.34° x 21.73°, pConclusion: Traditional adult acquired flatfoot deformity radiographic measurements are obtainable using high resolution 3D WB CBCT imaging. Measurements performed on WB CBCT have similar intra-observer and overall higher inter-observer reliability when compared to WB radiographs. The statistically significant differences found in some of the measurements, when comparing both imaging techniques, might be related to a better characterization of the three-dimensional deformity on WB CBCT images.

To assess high-bandwidth and compressed sensing-(CS)-SEMAC turbo spin echo (TSE) techniques for metal artifact reduction MRI of total ankle arthroplasty (TAA) implants. Following institutional approval and consent, 40 subjects with TAA implants underwent 1.5-T MRI prospectively. Evaluations included bone-implant interfaces, anatomical structures, abnormal findings and differential diagnoses before and after MRI. AUCs of P-P plots were used to determine superiority. Statistical differences were evaluated with McNemar and chi-square tests. P-values ≤ 0.05 were considered significant. CS-SEMAC TSE was superior to high-bandwidth TSE in showing the bone-implant interfaces (AUC=0.917), periprosthetic bone, tendons and joint capsule (AUC=0.337–0.766), bone marrow oedema (43 % difference, p=0.041), interface osteolysis (63 %, p=0.015), tendinopathy (62 %, p=0.062), periprosthetic fractures (60 %, p=0.250), synovitis (43 %, p=0.250), as well as reader confidence for bone marrow oedema (p=

A new technique in spring ligament reconstruction using medial half of posterior tibial tendon is demonstrated as a means of supporting the arch. In addition a new concept of double bundle PTT reconstruction based on anatomical attachments of original PTT is presented with the goal of obtaining the full function of PTT.

This study investigated the therapeutic potential of low-intensity pulsed ultrasound (LIPUS) in post-traumatic osteoarthritis (PTOA). Intra-articular fracture of the medial tibial plateau was surgically created in 30 rats. LIPUS was applied to the operated joints either for the first 2 wk (LIPUS1-2 group) or in weeks 4 and 5 after intra-articular fracture (LIPUS4-5 group). In controls, the operated knees were not treated with LIPUS (LIPUS0 group). The rats were monitored with weekly gait analysis and euthanized at week 8. Among the altered gait parameters, the maximal and average paw print areas in the LIPUS1-2 and LIPUS4-5 groups, but not the LIPUS0 group, had either reached baseline or significantly recovered (70%, p

In patients with chronic Achilles tendon disorders, Achilles tendon debridement can be supplemented with a tendon transfer, with the flexor hallucis longus tendon (FHL) transfer representing the most common used technique. Our study describes clinical and functional results of patients treated with flexor digitorum longus (FDL) tendon transfer in the treatment of patients with chronic Achilles tendon disorders.Retrospective study of prospectively collected data of thirteen patients (15 feet) that underwent FDL tendon transfer as part of the treatment of chronic Achilles tendon disorders. Preoperative and postoperative assessment included visual analogue score (VAS) for pain, SF-36 survey and lower extremity functional scale (LEFS). The average follow-up was 26.4 (range, 14-56) months. Patients were also assessed for ability to perform single leg heel rise test, muscle power for plantar flexion of the lesser toes, surgical scar condition and associated complications.At final follow-up, we found significant postoperative improvement in VAS score (6.6 ± 2.99 vs 1.06 ± 1.43; p .0001), SF-36 physical component summary (PCS) (28.20 ± 10.71 vs 45.04 ± 11.19; p .0001) and LEFS (36.13 ± 20.49 vs 58.73 ± 18.19; p .0001). Twelve patients (92%) could perform a single leg heel rise test in the operated extremity, although there was significant difference when comparing operated and uninvolved sides (4.86 ± 3.36 cm vs 7.18 ± 3.40 cm; p = .0002). One patient reported weakness for plantar flexion of the lesser toes, without balance or gait disturbances. Two patients (2 feet, 13.3%) had superficial infections and one patient (one foot, 6.6%) needed operative debridement for a deep infection.FDL tendon transfer represent an operative alternative in the treatment of chronic Achilles tendon disorders. Our study showed good clinical outcomes with low complications and donor site morbidity.Observational study, case series - level IV.

Osteochondral lesions of the talus present a formidable treatment challenge to the orthopaedic surgeon. Although debridement with either microfracture, drilling, or curettage is often successful in relieving pain and growing fibrocartilage within a standard lesion, the option of implanting particulated juvenile cartilage allograft has become a promising treatment alternative for patients who have failed routine treatment or who have osteochondral lesions that are known to do poorly from the onset. Particulated juvenile cartilage allograft transplantation delivers 1 mm3 of fresh juvenile cartilage, which contain live cells in their native extracellular matrix, that are secured into the osteochondral defect with the use of a fibrin adhesive. The current evidence, indications, and surgical technique for the use of particulated juvenile cartilage allograft transplantation in the management of osteochondral lesions of the talus have been reviewed.

Background: Tendinopathy is a clinical problem for which treatment shows mixed results and treatment options are limited. Gene expression signatures early in the mechanotransduction pathway can accurately predict risk and correlate with different clinical outcomes. Studies aimed at elucidating the molecular mechanisms of tendinopathy have focused on small cohorts of genes that show an incomplete picture of the degeneration process. This study compared the effect of cyclic strain on gene expression in tendon cells from normal tendon and chronically painful areas of tendinopathy in 3 patients. Methods: We measured a panel of mechanotransduction genes and cytoskeletal tensional balance with and without cyclic strain, which disrupts connective tissue synthetic-degradative equilibrium. Normal and degenerative tendons were obtained from patients undergoing surgery to treat chronic painful tendinopathy. A cyclic strain model was established to measure cytoskeletal tensional homeostasis. Results: Prior to cyclic strain, the normal tendon cells exhibited varying patterns of elevated expression of 7 genes compared with degenerative tendon cells. In response to cyclic strain, gene expression of COL1A1, ITGA6, CTNNA1, and CLEC3B was up-regulated in normal tendon cells. Cyclic strain had no effect on degenerative tendon cells. Cyclic strain exacerbated the inhibition of protein synthesis in both cell types, especially in the degenerative tendon cells. Conclusion: Alterations in the pattern of gene expression are suggestive of a dynamic equilibrium between synthesis and degradation, whereby cell adhesion molecules are predominantly up-regulated to facilitate cellular reorientation in response to their altered functional environment. Clinical Relevance: These data might have future applications, including the identification of markers for early diagnosis, targets for drug design, and indicators for treatment responsiveness and prognosis.

Introduction: Clinical assessment of hindfoot alignment (HA) in adult acquired flatfoot deformity (AAFD) can be challenging, and the weightbearing (WB) cone beam CT (CBCT) may potentially better demonstrate this three-dimensional (3D) deformity. Objective: To compare clinical and WB CBCT assessments of HA in patients with AAFD. Methods: In this prospective study, we included 12 men and 8 women (mean age: 52.2 years, range: 20-88) with flexible AAFD. All subjects also underwent WB CBCT and clinical assessment of hindfoot alignment. Three fellowship-trained foot and ankle surgeons performed six hindfoot alignment measurements on the CT images. Intra- and Inter-observer reliabilities were calculated using Intraclass correlation (ICC). Measurements were compared by paired T-tests, and p-values less than .05 were considered significant. Results: The mean of clinically measured hindfoot valgus was 15.2 (95% confidence interval [CI]: 11.5 - 18.8) degrees. It was significantly different from the mean values of all WB CBCT measurements: Clinical Hindfoot Alignment Angle, 9.9 (CI: 8.9 - 11.1) degrees; Achilles tendon/Calcaneal Tuberosity Angle, 3.2 (CI: 1.3 - 5.0) degrees); Tibial axis/Calcaneal Tuberosity Angle, 6.1 (CI: 4.3 - 7.8) degrees; Tibial axis/Subtalar Joint Angle, 7.0 (CI: 5.3 - 8.8) degrees, and Hindfoot Alignment Angle, 22.8 (CI: 20.4 - 25.3) degrees. We found overall substantial to almost perfect intra- (ICC range: 0.87-0.97) and interobserver agreement (ICC range: 0.51-0.88) for all WB CBCT measurements. Conclusion: Using 3D WB CBCT can help characterize the valgus hindfoot alignment in patients with AAFD. The different CT measurements were reliable and repeatable, significantly differing from the clinical evaluation of hindfoot valgus alignment.

Category: Sports Introduction/Purpose: Flexor digitorum longus (FDL) transfer to the lateral foot for concomitant irreparable rupture of the peroneal tendons has been reported in few clinical series. The purpose of this study is to provide midterm outcomes including subjective outcome scores, clinical examination data, and objective power after single-stage FDL tendon transfer. Methods: Twenty-five consecutive patients over a 7 year period (2008-2015) underwent FDL to fifth metatarsal transfer for irreparable peroneal tendon tears. Fifteen patients with a mean follow-up of 53.7 months completed the pain visual analog score (VAS), Foot Function Index (FFI), Short Musculoskeletal Functional Assessment (SMFA), and Foot and Ankle Ability Measure (FAAM) scores and participated in range of motion, peak force, and peak power testing. Results: All 15 patients were satisfied with their surgery and reported a reduction in their pain level with the average decrease in VAS of 5.59 +/- 2.5 (range: 1 - 9). The mean FAAM was 86.4 +/- 9.7 (range: 52.4 - 100). The mean FFI was 12.8 +/- 9.2 (range: 0 - 21.4). The mean SMFA Function index was 12.4 +/- 8 and the mean SMFA Bothersome Index was 11.5 +/- 11. Patients had on average 58% less eversion and 28% less inversion compared to the nonoperative side. Both isometric peak torque and isotonic peak velocity were decreased by 38.4% and 28.8%, respectively. On average, power in the operative limb was diminished by 56% compared to the nonoperative limb. Conclusion: FDL transfer to the lateral foot for significant, non-reconstructable peroneal tendinopathy is an effective, and durable treatment option.

Category: Hindfoot, Midfoot/Forefoot Introduction/Purpose: Both Evans and Hintermann procedures are opening wedge calcaneal osteotomies used for lateral column lengthening in flatfoot reconstruction. Risks of lateral column lengthening include lateral forefoot overload and increased calcaneocuboid (CC) joint pressure. The Evans osteotomy is preformed closer to the CC joint increasing the theoretical risk of higher CC pressures. The Hintermann technique is a more posteriorly located osteotomy developed to avoid destabilization of the anterior calcaneal fragment and subsequent CC joint incongruency. The purpose of this study is to biomechanically compare the Evans and Hintermann osteotomies through analysis of CC joint pressures and forefoot plantar pressures after sequential lengthening of the lateral column. Methods: A flatfoot model with radiographic confirmation was created in 10 matched cadaveric specimens which were then randomly selected to undergo either the Evans or Hintermann osteotomy. Specimens were physiologically loaded and the peak pressure of the CC joint and forefoot plantar pressures were measured under the following conditions: (1) intact foot, (2) flatfoot, and (3) sequential lengthening of the lateral column from 6 mm to 14 mm, in 2 mm increments. Results: Lateral column lengthening lead to significantly increased pressure across the CC joint in both the Evans and Hintermann specimens. With increasing lateral column length, mean peak CC pressures ranged from 2.9–4.0 and 1.2–2.2 times intact CC pressure for the Evans and Hintermann group, respectively. Normalized mean and normalized peak CC pressures were significantly higher in the Evans osteotomy group compared to the Hintermann group at every level of distraction (see figure). The CC pressures under each testing condition were normalized with respect to the intact foot. Forefoot lateral plantar pressures were significantly increased in specimens corrected with Evans osteotomy at 10 mm and 12 mm of distraction compared to the intact foot. Conclusion: The Evans osteotomy lead to significantly higher CC pressures than the Hintermann osteotomy. This data suggests the Hintermann osteotomy for flatfoot reconstruction minimizes increase in CC joint pressures and could reduce the risk of subsequent CC osteoarthritis.

Category: Ankle, Hindfoot Introduction/Purpose: The tall Controlled Ankle Motion (CAM) boot and the short CAM boot are commonly used devices to immobilize the foot and ankle. These devices are preferably used instead of casts and splints as they are easily removed, allowing possible wound examination, personal hygiene, and therapeutic exercises. However, the effect of these devices on joint contact pressures is unknown. The aim of this study is to assess the effect of the tall CAM boot and short CAM boot on contact pressures of the ankle, subtalar, talonavicular, and calcaneocuboid joints. We hypothesize that both the tall CAM boot and short CAM boot will reduce contact pressures of the ankle and hindfoot joints, with the tall CAM boot having the greatest effect. Methods: Eight lower extremity cadaver specimens were mounted on a servohydraulic test frame. The specimens were loaded to 700 N at a cyclical frequency of 1 Hz with the posterior tibial, peroneus longus, peroneus brevis, flexor hallucis longus, flexor digitorum longus, and Achilles tendon physiologically tensioned. TekScan (TekScan, Boston, MA) pressure sensors were placed in the ankle, subtalar, talonavicular, and calcaneocuboid joints. In the sagittal plane, the specimens were loaded on a neutral surface, followed by 20o of dorsiflexion. Each specimen served as its own control, with contact pressures measured with no immobilization (control), followed by placement in a short CAM boot and tall CAM boot. In addition, contact pressures in the immobilized limbs were measured at muscle loads both equal to and half of the load applied to the control in order to account for decreased muscle activation during immobilization. Results: There was no difference in the average and peak contact pressures of the ankle, subtalar, talonavicular and calcaneocuboid joints when comparing the short CAM boot to no immobilization at equal tendon loads. The tall CAM boot significantly decreased average and peak contact pressures of the ankle, subtalar, and talonavicular joints when compared to no immobilization. The reduction in contact pressures was accentuated when the load applied to the tendons was decreased in accordance with diminished muscle activation during immobilization. Neither immobilization device decreased the contact pressures of the calcaneocuboid joint at equal tendon loads. Conclusion: Immobilization in a tall CAM boot decreases contact pressures of the ankle and hindfoot in both a neutral position and in dorsiflexion. A tall CAM boot should be used clinically if the goal of its use is to maximally reduce contact pressures of the ankle and hindfoot.

Background Healthcare costs for the surgical management of ankle arthritis continue to rise. Patients are generally unaware of the prices of the services they use. Understanding the costs associated with surgical management of ankle arthritis is an important facet of patient care. The purposes of this study were to (1) determine the access to the surgical cost of total ankle arthroplasty (TAAs) and ankle arthrodesis and (2) the variability of the price between the two procedures. Methods Fifty foot and ankle centers (25 academic, 25 private) that perform TAAs and ankle arthrodeses were contacted using a standardized patient script. The described patient was a 63-year-old man who had failed conservative treatment of ankle arthritis. Each institution was contacted up to three times in an attempt to obtain a full-bundled surgical quote for a TAA and an ankle arthrodesis. Results Twenty-one centers (42%, 14 academic, 7 private) were able to provide a quote for a TAA and an ankle arthrodesis. The mean bundled price for a TAA was $50,332 (SD ± $25,744), with the mean academic and private center quote being $56,529 and $37,937, respectively. The mean bundled price for an ankle arthrodesis was $41,756 (SD ± $26,033), with the mean academic and private center quote being $48,116 and $29,037, respectively. No statistically significant difference was found between the bundled prices for TAA and ankle arthrodesis. Discussion This study demonstrated limited availability of consumer prices for TAA and ankle arthrodesis. When comparing different institutions for surgical management of ankle arthritis, there was a wide range of quotes for both TAA and ankle arthrodesis. When comparing the choice of surgical management for ankle arthritis, no statistically significant difference was observed in price between TAA and ankle arthrodesis.

Background: Tendon healing is a slow and complicated process that results in inferior structural and functional properties when compared to healthy tendon tissue. It may be possible to improve outcomes of tendon healing with enhancement of biological aspects of the repair including tissue structure, organization, and composition. The purpose of this study was to determine whether use of a stem cell-bearing suture improves Achilles tendon healing in a rat model. Methods: The Achilles tendon was transected in 108 bilateral hind limbs from 54 rats. Each limb was randomized to repair with suture only (SO), suture plus injection (SI) of mesenchymal stem cells (MSCs) at the repair site, or suture loaded with MSCs (suture with stem cells, SCS). One half of the animals were randomly sacrificed at 14 and 28 days after surgery and the Achilles tendon was harvested. From each repair group at each time point, 12 limbs were randomized to biomechanical testing and 6 to histologic analysis. Tendons were loaded using a 223-N load cell at 0.17 mm/s. A blinded pathologist scored the histology sections. Results: Ultimate failure strength (N/mm2) was significantly higher in the SI and SCS groups versus the SO group. In the SI group, ultimate failure strength decreased significantly at 28 days versus 14 days. Histology score in the SCS group was significantly lower (better) than in both other groups ( P ≤ .001). Histology findings at day 28 were significantly higher versus day 14 for all groups ( P = .01). Conclusions: Both the SI and the SCS groups had significantly higher ultimate failure strength versus the SO group, and strength was maintained at 28 days in the SCS group but not in the SI group. Histology in the SCS group was significantly better than in both other groups. Clinical Relevance: These findings in a rat model suggest that the use of stem cells enhances healing after Achilles repair and that embedding of stem cells directly into suture offers sustained early benefit to tendon healing.

Plantar fat pad (PFP) is a tissue structure that absorbs the initial impact of walking and running and ultimately bears body weight at standing. This study was designed to quantify the histomorphological changes of the PFP in aged rats. The most medial PFP was dissected from the hind feet of young rats (4 months old, n = 6) and aged rats (24 months old, n = 6). Histological structure and cellular senescence of PFP were analyzed stereologically and histomorphometrically. Immunohistochemistry of matrix metalloproteinase 9 (MMP9) was also performed on PFP tissue sections. Compared with young rats, the thickness of epidermis, dermis and septa of the PFP were significantly reduced in the aged rats. The total volume of adipose tissue in the PFP of aged rats was only about 65% of that in the young rats. The microvascular density and the number of fat pad units (FPU), a cluster of adipocytes enclosed by elastin septa, in the PFP were unchanged in the aged rats. In the aged rats, the number of adipocytes per FPU was reduced but the number of simple adipocyte clusters, without surrounding septa, was increased. The shift of the types of adipocyte clusters in the aged PFP was accompanied by degradation of elastin fibers and increased expression of MMP9. In conclusion, the PFP, particularly the elastic septa, degenerates significantly in aged rats and this may contribute to the pathology of PFP-related diseases.

Long echo train length (ETL) is an often recommended but unproven technique to decrease metal artifacts on magnetic resonance imaging (MRI) scans. Therefore, we quantitatively and qualitatively assessed the effects of ETL on metal artifact on MRI scans using a cobalt-chromium-containing arthroplasty implant system.Using a total ankle arthroplasty system implanted into a human cadaver ankle and a clinical 1.5 T MRI system, turbo spin echo (TSE) pulse sequences were acquired with ETL ranging from 3 to 23 and receiver bandwidth (BW) from 100 to 750 Hz/pixel, whereas effective echo time and spatial resolution were controlled. A compressed sensing slice encoding for metal artifact correction TSE prototype pulse sequence was used as reference standard. End points included the total implant-related artifact area and implant-related signal void areas. Two raters evaluated the overall image quality and preference across varying BW and ETL. Two-factor analysis of variance, Friedman test, Kruskal-Wallis test, and Pearson correlation were used. P values of less than 0.05 were considered statistically significant.The total implant-related artifact area ranged from 0.119 for compressed sensing slice encoding for metal artifact correction (BW, 600 Hz/pixel; ETL, 3) to 0.265 for TSE (BW, 100 Hz/pixel; ETL, 23). Longer ETL significantly increases the total implant-related artifact area (P = 0.0004), whereas it decreased with increasing BW (P0.0001). Implant-related signal void areas were not significantly affected by larger echo train length, but reduced with higher BW (P0.0001). Readers had a significant preference for images with high BW and short ETL (P0.0001).High receiver BW is the most effective parameter for reduction of arthroplasty implant-induced metal artifact on MRI scans, whereas in contradiction to prevalent notions, long echo trains fail to reduce implant-related metal artifacts, but in fact cause degradation of image quality around the implant with resultant larger appearing total metal artifacts.

Patients with insertional Achilles tendinopathy have pain at the bone-tendon interface, limited dorsiflexion, pain with active plantar flexion, pain with passive dorsiflexion, and prominence of the bone-tendon junction. Patients may also have retrocalcaneal bursitis, and in severe cases, the Achilles tendon proximal to the junction may have palpable thickening, warmth, and tenderness.

Background: In patients with Achilles tendinosis, Achilles tendon debridement can be supplemented with flexor hallucis longus tendon transfer. Outcomes have not been studied prospectively in older, sedentary, and overweight patients. Methods: Fifty-eight consecutive limbs in fifty-six consecutive older, sedentary patients with insertional or midsubstance Achilles tendinosis were enrolled prospectively and underwent the procedure. Ten patients were lost to follow-up, leaving forty-eight limbs in forty-six patients available for evaluation after twenty-four months. Results: The forty-six patients who were included in the study had an average age of 54 ± 10 years with an average body mass index of 33.8 ± 6.8 kg/m2. Significant improvement was observed between baseline and twenty-four months in terms of the visual analog scale for overall pain intensity (6.7 ± 2.3 versus 0.8 ± 2.0; p < 0.001), the Short Form-36 physical score (34.3 ± 8.0 versus 49.0 ± 9.3; p < 0.001), the Ankle Osteoarthritis Scale pain (54.4 ± 19.2 versus 1.9 ± 2.7; p < 0.001) and dysfunction (62.6 ± 21.4 versus 11.0 ± 24.2; p < 0.001) subscale scores, and performance of a single-leg heel rise (1.9 ± 3.0 versus 7.3 ± 2.7 cm; p < 0.001). Significant improvement compared with baseline was observed at three or six months except in the single-leg heel rise. Improvements in terms of pain and function occurred over twenty-four months, with the most improvement occurring in the first twelve months. At twenty-four months, maximum gastrocnemius circumference was significantly less in the involved compared with the uninvolved leg (40.2 ± 5.1 versus 41.2 ± 4.8 cm; p < 0.001). The mean passive range of motion of the first metatarsophalangeal joint decreased from 85.1° ± 25.3° preoperatively to 68.1° ± 36.7° (a 20% change) at six months (p = 0.03). Most patients reported no hallux weakness (57%; twenty-six of forty-six patients) and no loss of balance due to hallux weakness (76%; thirty-five of forty-six patients). Postoperative peroneal tendinitis was observed in seven patients. Complications included deep-vein thrombosis (two patients), superficial infection or delayed wound-healing (six), scar pain (four), and early disruption of the reconstruction due to a fall (one). Conclusions: Surgical debridement of the Achilles tendon with flexor hallucis longus tendon transfer was associated with significant improvement in terms of Achilles tendon function, physical function, and pain intensity in a group of relatively inactive, older, overweight patients. When present, hallux weakness had minimal functional sequelae. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

CD271 has been applied to isolate mesenchymal stem cells (MSCs) from bone marrow and other tissues. Umbilical cord blood is a unique resource of stem cells and endothelial progenitor cells. Isolation of MSCs from umbilical cord blood, however, has been inefficient and inconsistent. This study was designed to examine the potential application of CD271 as a marker for the isolation of MSCs from umbilical cord blood. CD271+ cells were isolated from umbilical cord blood and bone marrow using CD271 antibody-conjugated microbeads, and characterized in osteogenic, chondrogenic and adipogenic differentiation. CD271+ cells from umbilical cord blood were slow to proliferate compared with those isolated from bone marrow. While CD271+ cells from bone marrow differentiated into osteogenic, chondrogenic and adipogenic lineages, there were no sound indications of differentiation by CD271+ cells from umbilical cord blood under the same differentiation conditions applied to the CD271+ cells from bone marrow. The study also found that bone marrow CD271+ cells remarkably upregulated the expression of chondrogenic genes under chondrogenic differentiation induction. When implanted into bone defects in mice, CD271+ cells from bone marrow regenerated significant bone, but the counterparts in umbilical cord blood formed little bone in the bone defects. In conclusion, CD271 is an efficient marker for MSC isolation from bone marrow but has failed to isolate MSCs from umbilical cord blood. CD271+ cells in bone marrow are particularly chondrogenic. The property of CD271+ cells is unique but varies from different tissues.

Category: Midfoot/Forefoot Introduction/Purpose: Surgical treatment for osteoarthritis of the first metatarsophalangeal joint (MTPJ) includes cheilectomy or fusion for advanced arthritis. In addition, procedures to preserve or restore motion have demonstrated promising short-term results. Currently, no studies have described long-term results following interpositional arthroplasty. Our institution has performed interpositional arthroplasty with autograft (joint capsule/extensor hallucis brevis) or allograft (dermal matrix) with anecdotal success for over 15 years. The purpose of this study is to report long-term outcomes following interpositional arthroplasty. Methods: All patients undergoing interpositional arthroplasty at our institution from 2000-2015 were identified and a retrospective chart review was performed. Long-term follow-up was conducted through a telephone survey to obtain survivorship, satisfaction, and functional scores. Average follow-up was 89.1 months (range, 6 to 179 months). Survivorship of the interpositional arthroplasty procedure was defined as no subsequent surgery on the hallux after the index procedure. Results: From 2000-2015, 292 interpositional arthroplasties were performed at our institution. The overall failure rate was 1.7 % (5/292), which included patients requiring revision surgery (2 patients) or subsequent fusion (3 patients). Autograft interpositional arthroplasty had a failure rate of 2.1% (2/94) and allograft interposition was 1.5% (3/198). Failure and reoperation occurred at an average of 11 months from the index procedure (range, 6-17 months). 88.7% of patients rated their overall satisfaction as excellent or good. Average preoperative VAS score was 8.2 ± 1.5 (range, 6 to 10) and 2.1 ± 1.6 (range, 0 to 7) at latest follow-up, and (79.1%) patients reported tolerance to fashionable shoes. There were no major wound complications. The most common complications were metatarsalgia (8.6%) and cock-up deformity (5.7%). Conclusion: Interpositional arthroplasty demonstrated excellent long-term survivorship and high patient satisfaction at long-term follow-up.

Category: Basic Sciences/Biologics Introduction/Purpose: Managing Charcot Neuroarthropathy (CNA) remains a challenge facing the foot and ankle surgeons. Lack of understanding the pathogenesis of the disease prevents the development of novel therapies. Our previous studies revealed the involvement of fibroblast-like synoviocytes in the pathology of CNA. Residing in the synovium are also mesenchymal stem cells (MSCs), which maintain tissue homeostasis. In this study, MSCs isolated from the synovium of CNA and non-CNA patients were comparatively analyzed for their potential role in the pathology of CNA. Methods: Synovial samples were collected from CNA patients (n=7) and patients with osteoarthritis or intraarticular fracture (non-CNA; n=7), during foot and ankle procedures (approved by IRB). The synovial samples were minced and digested with 0.1% collagenase to isolate MSCs. The cells were plated and cultured in low density for counting colony-forming units-fibroblast (CFU- F), which is indicative of the number of MSCs. The colonies formed by CNA-MSCs and non-CNA MSCs were further characterized by size and imaging density. CNA-MSCs and non-CNA MSCs were cultured in adipogenic, osteogenic and chondrogenic differentiation media. The differentiation potentials of CNA-MSCs and non-CNA MSCs were assessed with histochemical staining and quantitative gene expression. Results: CFU-F: The number of colonies formed by CNA-MSCs was 6 ± 3.5 per (1/2) plate, while it was 43 ± 21.6 by the non- CNA MSCs (p < 0.05; Fig 1). The average size (pixels) of colonies was smaller in the CNA-MSCs than the non-CNA MSCs (4780 vs. 7960). When the colonies were stratified into high, medium and low density subgroups, colonies formed by the CNA-MSCs had a reduced density compared with the non-CNA MSCs (30±6 vs. 35±10) in the high density subgroup. Differentiation: Expression of adipogenic marker gene PPAR-γ by CNA-MSCs was less than half of that by non-CNA MSCs. The expression of osteogenic marker gene RUNX2 by CNA-MSCs was a third of that by the non-CNA MSCs. Similarly, the expression of chondrogenic marker genes, including SOX9 and type II collagen, by the CNA-MSCs declined as compared with the non- CNA MSCs. Conclusion: The synovium in CNA joints had fewer MSCs and that may impact joint’s response to inflammation and tissue repair. Furthermore, CNA-MSCs were declined in differentiation potentials. Analyses of the size and density of the colonies formed by CNA-MSCs showed that a subpopulation of MSCs was particularly affected. Further study will focus on the pathological role of the high-density subpopulation of MSCs in the development of CNA.

Background: Posttraumatic osteoarthritis (PTOA) is secondary to an array of joint injuries. Animal models are useful tools for addressing the uniqueness of PTOA progression in each type of joint injury and developing strategies for PTOA prevention and treatment. Hypothesis: Intra-articular fracture induces PTOA pathology. Study Design: Descriptive laboratory study. Methods: Through a parapatellar incision, the medial tibial plateau was exposed in the left knees of 8 Sprague-Dawley rats. Osteotomy at the midpoint between the tibial crest and the outermost portion of the medial tibial plateau, including the covering articular cartilage, was performed using a surgical blade. The fractured medial tibial plateau was fixed with 2 needles transversely. The fractured knees were not immobilized. Before and after surgery, rat gait was recorded. Rats were sacrificed at week 8, and their knees were harvested for histology. Results: After intra-articular fracture, the affected limbs altered gait from baseline (week 0). In the first 2 weeks, the gait of the operated limbs featured a reduced paw print intensity and stride length but increased maximal contact and stance time. Reduction of maximal and mean print area and duty cycle (the percentage of stance phase in a step) was present from week 1 to week 5. Only print length was reduced in weeks 7 and 8. At week 8, histology of the operated knees demonstrated osteoarthritic pathology. The severity of the PTOA pathology did not correlate with the changes of print length at week 8. Conclusion: Intra-articular fracture of the medial tibial plateau effectively induced PTOA in rat knees. During PTOA development, the injured limbs demonstrated characteristic gait. Clinical Relevance: Intra-articular fracture represents severe joint injury and associates with a high rate of PTOA. This animal model, with histologic and gait validations, can be useful for future studies of PTOA prevention and early diagnosis.

Background: It may be possible to avoid malleolar osteotomy for treatment of osteochondral talar lesions with chondrocyte transplantation techniques, where perpendicular approach to the talar surface is not required. We hypothesized that limited anterior distal tibial plafondplasty would allow access to most of the talar surface. We compared talar access with soft tissue exposure versus plafondplasty. Methods: Two soft tissue exposures (anteromedial and anterolateral) and two limited anterior distal tibial plafondplasties (anteromedial and anterolateral) were used on 12 cadaver lower-extremity specimens. Digital analysis was used to assess the accessible area. Results: Percentage of total talar dome surface area access increased significantly between soft tissue exposure and limited plafondplasty medially (22.3 ± 6.3% versus 37.9 ± 4.6%; p < 0.001) and laterally (22.4 ± 7.7% versus 37.9 ± 7.7%; p < 0.001). Percentage sagittal plane access also increased significantly between soft tissue exposure and limited plafondplasty medially 54.4 ± 12.0% versus 81.3 ± 9.7%; p < 0.001) and laterally (53.3 ± 14.5% versus 80.9 ± 12.8%; p < 0.001). Limited exposure to an additional 14.2 ± 5% of the total talar surface area was possible. The posterior 10.6 ± 8% was inaccessible. Conclusions: A soft tissue approach with limited plafondplasty provided adequate exposure for the majority of the medial and lateral talar surface. Only the central posterior 10% of the talus was not accessed by this method. Clinical Relevance: It may be possible to avoid malleolar osteotomy by using limited plafondplasty to access the talar dome for treatment of osteochondral lesions if perpendicular access to the talus is not required.

Background: We compared forefoot and calcaneocuboid pressure in isolated medial column fusion (1-3 tarsometatarsal fusion) versus medial and lateral column fusion (1-5 tarsometatarsal fusion) in a neutral, inversion, and eversion loading model in stance gait phase. Methods: Twelve fresh-frozen cadaveric specimens were cyclically loaded to 720 N at 0.5 Hz for 30 cycles. Plantar and calcaneocuboid joint pressures were measured in neutral, inversion, and eversion in the intact foot, with isolated medial column fusion, and with medial and lateral column fusion. Results: Lateral pressure was higher in the medial and lateral column fusion group than isolated medial column fusion and intact in neutral (55.8 ± 14.8 versus 46.2 ± 13.6 and 45.5 ± 14.8 kPa, respectively) and eversion (80.7 ± 18.4 versus 61.8 ± 13.7 and 60.2 ± 18.2 kPa, respectively) ( p ≤ 0.001). Calcaneocuboid pressure was higher in medial and lateral column fusion than isolated medial column fusion and intact in neutral (1436.7 ± 210.6 versus 1073.7 ± 282.5 and 1084.9 ± 337.6, respectively; p = 0.001) and inversion (1518.3 ± 270.5 versus 1310.5 ± 298.8 and 1237.1 ± 401.9, respectively; p = 0.02). Using combined position data, calcaneocuboid pressure was significantly higher in the medial and lateral column group than in both other groups. The isolated medial column fusion group did not differ significantly from the intact group in any measurement. Conclusion: Medial and lateral column fusion significantly increased lateral and calcaneocuboid pressures with loading compared with isolated medial column fusion and the intact state. No difference was observed between isolated medial column fusion and the intact state. Clinical Relevance: It may be advisable to avoid fusing the lateral column in tarsometatarsal arthrodesis if possible to avoid pressure increase in the forefoot and hindfoot.

Platelet-rich plasma (PRP) contains growth factors derived from venous blood. Bone marrow concentrate (BMC) is an analogous platelet-rich product that is generated from bone marrow aspirate and might have the added advantage of containing mesenchymal stem cells. The active growth factors are platelet-derived growth factor, transforming growth factor β, vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor, and epidermal growth factor. It is probable that a multitude of factors and cells play a role in inducing healing of hard or soft tissues that have been acutely or chronically injured or diseased. PRP can be used alone or in conjunction with surgical reconstruction to achieve better healing of tissues. Our group has treated 634 patients with PRP or BMC for nonunions, malunions, arthritis, malalignments, tendinopathies, tendon ruptures, plantar fasciitis, fractures, or ligament injuries that were performed in a variety of healthy and unhealthy patients. Overall, the results were favorable with very limited morbidity. In general, healing was more complete and rapid compared with historic norms, but failures can still occur. Condition-specific retrospective and prospective studies are underway to further establish the role of PRP in foot and ankle conditions and reconstructions.

The Girdlestone flexor-to-extensor transfer was first described by Taylor in 1951. He described a technique whereby transferring the toe flexors to the dorsum of the proximal phalanx, one "restores us...

Osteochondral lesions of the talus present a formidable treatment challenge to the orthopedic surgeon. This explains the multitude of treatment options described for this pathology. Currently, in the United States, surgical treatment options for symptomatic lesions are: debridement; marrow stimulation including drilling, microfracture, and abrasion arthroplasty; osteochondral autograft transfer; fresh osteochondral allograft transplantation; and the recently introduced technique of particulated juvenile cartilage allograft transplantation. The appropriate surgical therapy is based on patient and lesion-specific factors. This article will provide a brief review of these surgical therapies and the technique for particulated juvenile cartilage allograft transplantation.

A high degree of suspicion for lateral process talus fracture is needed in patients with lateral ankle pain after a kayaking or similar paddling sport injury.

Category: Ankle Introduction/Purpose: The distal tibiofibular syndesmosis maintains the integrity of ankle mortise during weight bearing. Syndesmotic injuries are common and even slight malreduction are associated with long-term development of tibiotalar osteoarthritis. Radiographic as well as CT based measurements are being employed to detect syndesmotic injuries, however, subtle injuries are commonly overlooked. In the present study we intend to investigate whether measurements obtained from weight-bearing (WB) cone-beam computed tomography (CBCT) images are different from measurements obtained from NWB images in subjects with clinical suspicion of syndesmotic injury and “inconclusive” plain radiograph findings Methods: In this prospective study, following IRB approval, the injured ankles of 20 patients (10 men and 10 women; mean age: 46.1 years; range: 19-82) with persistent ankle pain following ankle trauma and clinical suspicion of syndesmotic injury underwent simultaneous WB and NWB CBCT scans. Following a detailed literature review, a set of 21 syndesmotic related measurements in all WB and NWB images, assessing fibular displacement in medio-lateral, cranio-caudal, antero-posterior planes were performed by three independent readers. Inter-observer and intra-observer reliabilities were evaluated by intra-class correlation (ICC) and Pearson/Spearman’s correlation, respectively. We used Paired student t-tests or Wilcoxon-rank-sum tests to compare the measurements from the two scans. Bootstrapping with 10000 samples was used to extract P-values for 99% uncertainty levels Results: we observed almost perfect intra-observer reliability for WB and NWB measurements (r = 0.8-0.98). Inter-observer reliability was significant for all measurement with overall fair to perfect agreement (ICC=0.36-0.97). Mean values of medio-lateral measurements including posterior tibiofibular distance, tibiofibular clear space and diastasis were significantly higher in WB images compared to NWB CBCT images (P-value< 0.05). Mean values of angular measurement, bi-malleolar angle, lateral clear space and fibular length were significantly lower in WB images (P-valueConclusion: Of syndesmotic measurements available in the literature, certain measurements are different between WB and NWB CBCT examinations with moderate to perfect intra- and inter-observer reliability in post-traumatic ankles with clinical suspicion of syndesmotic injury and inconclusive plain radiographs. These measurements should be further investigated for detection of biomechanical instability associated with syndesmotic injury compared to those obtained from asymptomatic ankles

Category: Trauma Introduction/Purpose: No consensus exists regarding postoperative rehabilitation protocols after surgical fixation of unstable trimalleolar ankle fractures with large posterior malleolar fragments. Additionally, no consensus exists regarding type of fixation of large posterior malleolar fragments in these fractures. It is unclear whether clinical results with early weightbearing differ between large posterior malleolar fragments fixed with either screws alone or a plate and screws construct. We evaluated fracture displacement with simulated early weightbearing in a cadaveric model. Methods: Sixteen fresh-frozen lower extremities were assigned to Group 1, trimalleolar ankle fracture with a large posterior malleolar fragment fixed with screws (n=8) or Group 2, trimalleolar ankle fracture with a large posterior malleolar fragment fixed with a plate and screws construct (n=8). Both Groups were tested with an axial compressive load at 3.2 Hz from 100 to 1,000 N and internal/external torque at 1.6 Hz at 0.5 Nm for 250,000 cycles to simulate 5 weeks of full weightbearing. Displacement was measured by differential variable reluctance transducer. Results: The average motion at all fracture sites in both groups was less than 1 mm. Group 1 displacement of the medial, lateral, and posterior malleolar fracture was 0.30 ± 0.27 mm, 0.12 ± 0.11 mm, and 0.87 ± 0.68 mm respectively. Group 2 displacement of the medial, lateral, and posterior malleolar fracture was 0.78 ± 1.52 mm, 0.12 ± 0.16 mm, and 0.87 ± 1.20 mm respectively. There was no significant difference between the average motion at all fractures sites between Group 1 and Group 2 (P > 0.05). There was no statistical correlation between fracture displacement and bone mineral density. Conclusion: This study supports early weightbearing after surgical fixation of unstable trimalleolar ankle fractures regardless of type of fixation of the posterior malleolus. Further investigation of early weightbearing protocols after surgical fixation of unstable trimalleolar ankle fractures are needed to help guide future treatment.

Nonsurgical management is preferred in most ankle sprains, even in the athletic population. However, patients presenting with chronic lateral ankle instability refractory to an appropriate bracing and rehabilitation program may benefit from lateral ligament reconstruction. Recognition and management of other associated injuries or conditions is critical to a successful outcome. We present 2 surgical techniques for reconstruction of the lateral ankle ligaments in athletes. The periosteal flap augmentation of the modified Brostrom reconstruction should be considered for primary cases. Patients who have failed prior surgical reconstruction or have a systemic condition resulting in generalized ligamentous laxity may require further surgical augmentation with an anatomical allograft ligament reconstruction technique.

Our goal was to develop a novel technique for inducing Achilles tendinopathy in animal models which more accurately represents the progressive histological and biomechanical characteristic of chronic Achilles tendinopathy in humans. In this animal research study, forty-five rabbits were randomly assigned to three groups and given bilateral Achilles injections. Low dose (LD group) (n = 18) underwent a novel technique with three low-dose (0.1mg) injections of collagenase that were separated by two weeks, the high dose group (HD) (n = 18) underwent traditional single high-dose (0.3mg) injections, and the third group were controls (n = 9). Six rabbits were sacrificed from each experimental group (LD and HD) at 10, 12 and 16 weeks. Control animals were sacrificed after 16 weeks. Histological and biomechanical properties were then compared in all three groups. At 10 weeks, Bonar score and tendon cross sectional area was highest in HD group, with impaired biomechanical properties compared to LD group. At 12 weeks, Bonar score was higher in LD group, with similar biomechanical findings when compared to HD group. After 16 weeks, Bonar score was significantly increased for both LD group (11,8±2,28) and HD group (5,6±2,51), when compared to controls (2±0,76). LD group showed more pronounced histological and biomechanical findings, including cross sectional area of the tendon, Young's modulus, yield stress and ultimate tensile strength. In conclusion, Achilles tendinopathy in animal models that were induced by serial injections of low-dose collagenase showed more pronounced histological and biomechanical findings after 16 weeks than traditional techniques, mimicking better the progressive and chronic characteristic of the tendinopathy in humans.

An accurate assessment of the foot and ankle problem in elite athletes is the foundation of a treatment plan and prognosis. The special pressures of professional sports, where managers, agents, and lawyers may be involved, makes a thorough assessment especially critical for sound decision-making. Evaluation includes taking a history of the acute and chronic condition, including mechanism, physical sensation at injury, compensatory stresses, and general medical review. The athlete is assessed physically in several different ways, including comprehensive focal examination and alignment in static and dynamic nonweight-bearing and weight-bearing modes. This comprehensive process is essential to accurate assessment.

Little has been reported about the biologic effect of shock waves on human normal or pathologic tendon tissue. We hypothesized that inflammatory cytokine and MMP production would be down-regulated by shock wave stimulation.Diseased Achilles tendon tissue and healthy flexor hallucis longus tissue were used. Shock wave treatment was applied to cultured cells at 0.17 mJ/mm(2)energy 250, 500, 1000, and 2000 times.A dose-dependent decrease in cell viability was noted in cells receiving 1000 and 2000 shocks (86.0 +/- 5.6%, p = 0.01 and 72.4 +/- 8.9%, p = 0.001) as compared with the normal control. Cell count in the 500-shock group increased by 23.4% as compared with the control (p = 0.05). The concentration of MMP 1, 2, and 13 was higher in diseased tenocytes as compared with normal cells (p = 0.04, all comparisons). IL-6 levels were higher in the diseased tenocytes as compared with normal tenocytes (44.10 +/- 16.72 versus 0.21 +/- 0.55 ng/ml, (p0.05). IL-1 levels in normal cells increased (2.24 +/- 5.02 ng/ml to 9.31 +/- 6.85 ng/ml) after shock wave treatment (p = 0.04). In diseased tenocytes, levels of MMP-1 (1.12 +/- 0.23 to 0.75 +/- 0.24 ng/ml; p = 0.04) and MMP-13 (1.43 +/- 0.11 to 0.80 +/- 0.15 ng/ml; p = 0.04) were significantly decreased after shock wave treatment. The IL-6 level in diseased tenocytes was decreased (44.10 +/- 16.72 to 14.66 +/- 9.49 ng/ml) after shock wave treatment (p = 0.04).Higher levels of MMPs and ILs were found in human tendinopathy-affected tenocytes as compared with normal cells. ESWT decreased the expression of several MMPs and ILs.This mechanism may play an important role in shock wave treatment of tendinopathy clinically.

Background: Little has been reported about the biologic effect of shock waves on human normal or pathologic tendon tissue. We hypothesized that inflammatory cytokine and MMP production would be down-regulated by shock wave stimulation. Materials and Methods: Diseased Achilles tendon tissue and healthy flexor hallucis longus tissue were used. Shock wave treatment was applied to cultured cells at 0.17 mJ/mm 2 energy 250, 500, 1000, and 2000 times. Results: A dose-dependent decrease in cell viability was noted in cells receiving 1000 and 2000 shocks (86.0 ± 5.6%, p = 0.01 and 72.4 ± 8.9%, p = 0.001) as compared with the normal control. Cell count in the 500-shock group increased by 23.4% as compared with the control (p = 0.05). The concentration of MMP 1, 2, and 13 was higher in diseased tenocytes as compared with normal cells (p = 0.04, all comparisons). IL-6 levels were higher in the diseased tenocytes as compared with normal tenocytes (44.10 ± 16.72 versus 0.21 ± 0.55 ng/ml, (p < 0.05). IL-1 levels in normal cells increased (2.24 ± 5.02 ng/ml to 9.31 ± 6.85 ng/ml) after shock wave treatment (p = 0.04). In diseased tenocytes, levels of MMP-1 (1.12 ± 0.23 to 0.75 ± 0.24 ng/ml; p = 0.04) and MMP-13 (1.43 ± 0.11 to 0.80 ± 0.15 ng/ml; p = 0.04) were significantly decreased after shock wave treatment. The IL-6 level in diseased tenocytes was decreased (44.10 ± 16.72 to 14.66 ± 9.49 ng/ml) after shock wave treatment (p = 0.04). Conclusion: Higher levels of MMPs and ILs were found in human tendinopathy-affected tenocytes as compared with normal cells. ESWT decreased the expression of several MMPs and ILs. Clinical Relevance: This mechanism may play an important role in shock wave treatment of tendinopathy clinically.

Background: Elongation of ligaments during early mobilization after reconstruction may be associated with decreased stability. We evaluated elongation of the anterior talofibular ligament (ATFL) before and after lateral ligament reconstruction within a physiologic range of motion with protected and unprotected, isolated dorsiflexion/plantarflexion range of motion. Materials and Methods: Six fresh frozen cadaver legs were used with the ATFL meticulously dissected. A differential variable reluctance transducer (DVRT) was spaced to span the course of the ATFL using consistent placement points based on previous reports. Elongation was measured in a load frame with protected motion of 30 degrees plantarflexion and 10 degrees dorsiflexion for the intact and sectioned ATFL and for the repaired specimen with and without protected motion. The proximal DVRT anchor point was detached for sectioning and repair of the ATFL and replaced at the same position. Testing was 1000 cycles at 1 Hz for the repaired protected specimen and 10 cycles at 1 Hz for all other stages. Results: Initial elongation in the unprotected, repaired group was significantly higher than initial elongation in the intact ( p < 0.01), sectioned ( p = 0.02), and repaired, protected ( p < 0.01) groups. Final elongation in the unprotected repaired group was also higher than final elongation in all other groups ( p < 0.01 for all comparisons). Conclusion: The use of protected range of motion of the ankle after lateral ankle ligament reconstruction was not associated with elongation of the ATFL. The ATFL elongated significantly by comparison without protected dorsiflexion/plantarflexion. Clinical Relevance: The study provides biomechanical support for the safety of early protected dorsiflexion/plantarflexion range of motion after Broström reconstruction.

Background: We hypothesized that a dorsomedial locking plate with adjunct screw compression would provide superior rigidity compared to crossed screws for first metatarsocuneiform (MTC) arthrodesis. Materials and Methods: In ten matched lower extremity pairs, specimens in each pair were randomly assigned to receive screw fixation or plate with screw fixation. Bone mineral density (BMD) was measured. For the crossed-screw construct, two 4.0-mm cannulated screws were used. One screw was inserted dorsal to plantar beginning from the first metatarsal 10 to 15 mm distal to the joint, and the second was inserted from the cuneiform 8 to 10 mm proximal to the joint, medial to the first screw, into the first metatarsal. For the plate construct, a 4.0-mm cannulated compression screw was inserted from the dorsal cortex of the first metatarsal to the plantar aspect of the medial cuneiform. A locking plate was inserted dorsomedially across the MTC joint. Specimens were loaded in four-point bend configuration (displacement rate, 5 mm/min) until failure of the fixation or 3-mm deformation. An extensometer was used to measure deformation. Results: There was no difference in load to failure or stiffness between the two groups. BMD was positively correlated with load to failure in the screw ( r = 0.893, p = 0.001) and the plate ( r = 0.858, p = 0.001) construct. Conclusion: The plate construct with compression screw did not show different rigidity as compared with the screw construct with the numbers available. Clinical Relevance: Further investigation of a dorsomedial plate with adjunct screw compression may be warranted for first MTC arthrodesis.

Background: The effect of the Cotton osteotomy has not been studied in isolation, and no alternative to bone graft has been investigated for this osteotomy. We hypothesized that there would be no difference in radiographic and pressure findings using the Cotton osteotomy with bone graft or an opening wedge block plate. Materials and Methods: Each specimen of eight matched pairs of lower extremities was loaded in simulated double-leg stance via pneumatic cylinders as described previously. Weightbearing lateral and anteroposterior radiographs and medial and lateral pressure measurements were obtained for all intact specimens. Specimens were randomly assigned to receive a Cotton osteotomy with a dorsal opening wedge allograft or an opening wedge plate. Each specimen was cycled at 3 Hz to 720 N for 5000 cycles and measurements were repeated. Results: Calcaneal pitch was lower after the block plate procedure (mean ± standard error of the mean) (intact, 23.4 ± 1.2 degrees versus post-procedure, 21.8 ± 1.1 degrees; p = 0.05). There was a significant difference ( p < 0.05) in percentage of total plantar pressure medially and laterally between the intact specimen and the specimen after osteotomy with both methods. Pressure increased medially and decreased laterally. Conclusion: With the numbers available, these methods for performing a Cotton osteotomy did not differ in addressing lateral column overload. Clinical Relevance: Dorsal opening wedge medial cuneiform osteotomy performed with femoral head allograft or a block plate may be effective both in reducing lateral column pressures and increasing medial column pressures when they are deficient preoperatively.