Faculty Bibliography

PURPOSE/OBJECTIVE:Optimal treatment of acute Achilles tendon ruptures remains controversial. Positive results using stem-cell-bearing concentrates have been reported with other soft-tissue repairs, but no studies exist on outcomes of bone marrow aspirate concentrate (BMAC) augmentation in primary Achilles tendon repair. METHODS:We reviewed patients with sport-related Achilles tendon ruptures treated via open repair augmented with BMAC injection from 2009 to 2011. Data on operative complications, strength, range of motion, rerupture, calf circumference and functional improvement through progressive return to sport and the Achilles tendon Total Rupture Score (ATRS) were analysed. RESULTS:A total of 27 patients (28 tendons) treated with open repair and BMAC injection were identified (mean age 38.3 ± 9.6 years). At mean follow-up of 29.7 ± 6.1 months, there were no reruptures. Walking without a boot was at 1.8 ± 0.7 months, participation in light activity was at 3.4 ± 1.8 months and 92% (25 of 27) of patients returned to their sport at 5.9 ± 1.8 months. Mean ATRS at final follow-up was 91 (range 72-100) points. One case of superficial wound dehiscence healed with local wound care. No soft-tissue masses, bone formation or tumors were observed in the operative extremity. CONCLUSIONS:Excellent results, including no re-ruptures and early mobilisation, were observed in this small cohort with open Achilles tendon repair augmented by BMAC. No adverse outcomes of biologic treatment were observed with this protocol. The efficacy of BMAC in the operative repair of acute Achilles tendon ruptures warrants further study. LEVEL OF EVIDENCE/METHODS:IV - Therapeutic.

The management of posterior tibial tendon dysfunction in adults has evolved substantially, and controversy persists regarding a specific recommended algorithm for treatment. The current focus is on early diagnosis and treatment of this disorder with joint-sparing surgeries, such as corrective osteotomies and tendon transfers, when nonsurgical modalities have been exhausted. It is helpful to be familiar with the pertinent pathophysiology and diagnostic pearls associated with posterior tibial tendon dysfunction, its treatment options, pertinent literature, and technique tips for the procedures currently being used.

OBJECTIVES/OBJECTIVE:This study aimed to investigate the pathology occurring at the calcified zone of articular cartilage (CZC) in the joints afflicted with post-traumatic osteoarthritis (PTOA). METHODS:Rats underwent bilateral anterior cruciate ligament (ACL) transection and medial meniscectomy to induce PTOA. Sham surgery was performed on another five rats to serve as controls. The rats were euthanized after four weeks of surgery and tibial plateaus were dissected for histology. The pathology of PTOA, CZC area and the tidemark roughness at six pre-defined locations on the tibial plateaus were quantified by histomorphometry. RESULTS:PTOA developed in the knees, generally more severe at the medial plateau than the lateral plateau, of rats in the experimental group. The CZC area was unchanged in the PTOA joints, but the topographic variations of CZC areas that presented in the control knees were reduced in the PTOA joints. The tidemark roughness decreased in areas of the medial plateau of PTOA joints and that was inversely correlated with the Mankin's score of PTOA pathology. CONCLUSION/CONCLUSIONS:Reduced tidemark roughness and unchanged CZC area differentiate PTOA from primary osteoarthritis, which is generally believed to have the opposite pathology at CZC, and may contribute to the distinct disease progression of the two entities of arthropathy.

BACKGROUND:There is a paucity of research on posttraumatic ankle arthritis (PTAA). We aimed to identify synovial fluid PTAA biomarkers using cytokine analysis and metabolic profiling. METHODS:Ankle joint synovial fluid was obtained from 20 patients with PTAA and 20 patients with no ankle pain and no radiographic evidence of ankle arthritis (control group). Synovial fluid samples were analyzed for IFN-γ, TNF-α, MIP-1β, MCP-1, IL-1β, IL-1Ra, IL-4, IL-6, IL-8, IL-10, IL-13, and IL-15 using ELISA and for more than 3000 metabolites using liquid and gas chromatography with mass spectroscopy. To compare presence of cytokines and metabolites between groups, t tests were used. Random forest analysis was performed on metabolites to determine whether control and PTAA samples could be differentiated based on metabolic profile. RESULTS:IL-1Ra, IL-6, IL-8, IL-10, IL-15, and MCP-1 were significantly elevated in the PTAA group. In addition, 107 metabolites in the PTAA group were significantly altered, including derangement in amino acid, carbohydrate, lipid, and energy metabolism, extracellular matrix turnover, and collagen degradation. Random forest analysis yielded a predictive accuracy of 90% when using the metabolic profiles to distinguish between control and PTAA samples. CONCLUSION/CONCLUSIONS:This study identified inflammatory cytokines and metabolites present in the synovial fluid of PTAA. CLINICAL RELEVANCE/CONCLUSIONS:Several of these entities have previously been implicated in rheumatoid arthritis and osteoarthritis of the knee, but many could potentially be used as novel biomarkers of PTAA. Most importantly, the findings suggest that metabolites could be used to distinguish synovial fluid from patients with PTAA.

UNLABELLED:Osteochondral lesions of the talus (OLT) are commonly associated with traumatic injury to the ankle joint. Treatment options depend on the grade, location, and size of the lesion. Operative intervention is frequently required with initial management involving marrow stimulation techniques, such as microfracture/curettage. Larger lesions often require a secondary procedure, such as osteochondral transplantation or autologous chondrocyte implantation. The advent of particulated juvenile articular cartilage (PJAC) provides an alternative method for OLTs refractory to traditional treatments. This article describes the technique of PJAC transplantation for the treatment of osteochondral lesions of the talus. LEVEL OF EVIDENCE/METHODS:Level V, expert opinion.

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/CONCLUSIONS: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/CONCLUSIONS: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.

OBJECTIVES/OBJECTIVE:The purpose of this study was to investigate the efficacy of a composite surgical mesh for delivery of mesenchymal stem cells (MSCs) in tendon repair. METHODS:The MSC-loaded mesh composed of a piece of conventional surgical mesh and a layer of scaffold, which supported MSC-embedded alginate gel. A 3-mm defect was surgically created at the Achilles tendon-gastrocnemius/soleus junction in 30 rats. The tendon defects were repaired with either 1) MSC-loaded mesh; or 2) surgical mesh only; or 3) routine surgical suture. Repaired tendons were harvested at days 6 and 14 for histology, which was scored on the bases of collagen organization, vascularity and cellularity, and immunohistochemisty of types I and III collagen. RESULTS:In comparison with the other two repair types, at day 6, the MSC-loaded mesh significantly improved the quality of the repaired tendons with dense and parallel collagen bundles, reduced vascularity and increased type I collagen. At day 14, the MSC-loaded mesh repaired tendons had better collagen formation and organization. CONCLUSION/CONCLUSIONS:The MSC-loaded mesh enhanced early tendon healing, particularly the quality of collagen bundles. Application of the MSC-loaded mesh, as a new device and MSC delivery vehicle, may benefit to early functional recovery of the ruptured tendon.

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/mm(2)) 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/CONCLUSIONS: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.

Operative foot and ankle osteomyelitis is challenging for orthopedic surgeons because of the area’s unique anatomy, high trauma incidence, local and systemic disease effects, and often limited space. Standard treatment includes aggressive operative debridement with local and systemic antibiotic administration to control infection. Dead space management is critical yet technically demanding. The authors report a modified antibiotic cement bead therapy technique in which antibiotic sticks, minnows, and mushroom-shaped plugs are used to strike a balance between the stability of the load-bearing unit and radical removal of infection to preserve a functional foot. Three cases are presented.