Total Ankle Replacement for Treatment of End-Stage Osteoarthritis in Elderly Patients

End-stage osteoarthritis of the ankle is a disabling problem, particularly in elderly patients who experience an overall loss of mobility and functional impairment and who then need compensatory adaption. Ankle arthrodesis, which has been demonstrated to provide postoperative pain relief and hindfoot stability, leaves the patient with a stiff foot and gait changes. For elderly patient, these changes may be more critical than generally believed. Additionally, the long duration of healing and rehabilitation process needed for ankle arthrodesis may be problematic in the elderly. In contrast to ankle arthrodesis, total ankle replacement has significant advantages including a less strenuous postoperative rehabilitation and preservation of ankle motion which supports physiological gait. Recently, total ankle replacement has evolved as a safe surgical treatment in patients with end-stage ankle osteoarthritis with reliable mid- to long-term results. Total ankle replacement needs less immobilization than arthrodesis and does allow for early weight-bearing and should be considered as a treatment option of first choice in many elderly patients with end-stage osteoarthritis of the ankle, especially in elderly patients with lower expectations and physical demands

IL-23 stabilizes an effector Treg cell program in the tumor microenvironment

Interleukin-23 (IL-23) is a proinflammatory cytokine mainly produced by myeloid cells that promotes tumor growth in various preclinical cancer models and correlates with adverse outcomes. However, as to how IL-23 fuels tumor growth is unclear. Here, we found tumor-associated macrophages to be the main source of IL-23 in mouse and human tumor microenvironments. Among IL-23-sensing cells, we identified a subset of tumor-infiltrating regulatory T (T-reg) cells that display a highly suppressive phenotype across mouse and human tumors. The use of three preclinical models of solid cancer in combination with genetic ablation of Il23r in T-reg cells revealed that they are responsible for the tumor-promoting effect of IL-23. Mechanistically, we found that IL-23 sensing represents a crucial signal driving the maintenance and stabilization of effector T-reg cells involving the transcription factor Foxp3. Our data support that targeting the IL-23/IL-23R axis in cancer may represent a means of eliciting antitumor immunity

Search for dark matter in events with heavy quarks and missing transverse momentum in pp collisions with the ATLAS detector

This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb$^{-1}$ of $pp$ collisions collected at $\sqrt{s} = 8$ TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing $b$-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter--nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a coloured mediator suitable to explain a possible signal of annihilating dark matter.Comment: 10 pages plus author list + cover pages (25 pages total), 7 figures, 2 tables, submitted to Eur. Phys. J. C, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2014-01

Syndesmotic Instability After Total Ankle Replacement

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacement (TAR) evolved over the last decades and has been shown to be an effective concept in the treatment of ankle osteoarthritis (OA). In three-component designs, the second interface between polyethylene insert (PI) and tibial component allows the PI to find its position according the individual physiological properties. This was believed to decrease shear forces within the ankle joint. However, it is not clarified to which extent such an additional degree of freedom may overload the ligamentous structures of the ankle joint over time. This may in particular be the case for the syndesmotic ligaments. Therefore, the purpose of this study was to analyze all ankles after TAR that showed a symptomatic overload of the syndesmotic ligaments and to determine the potential consequences. Methods: Between 2003 and 2017, 31 ankles (females, 17; males 14; mean age 60 [40-79] years) were treated with a tibio-fibular fusion for a symptomatic instability of the syndesmosis. The indication for TAR was posttraumatic OA in 27 (87%), primary OA in 3 (10%), and hemochromatosis in one ankle (3%). The 31 ankles included 23 primary TAR (74%), 6 revision TAR (19%), and two take-down of a fusion and conversion to TAR (7%). Criteria for fusion were the presence of at least two of the followings: (1) tenderness over the syndesmosis, (2) pain while compressing the fibula against the tibia (squeeze test), (3) pain while rotating the foot externally (external rotation test), (4) widening of the syndesmosis on an anteroposterior view. Alignment of TAR (tibial articular surface [TAS] angle) and hindfoot alignment were measured on standard radiographs. Intraoperatively, the syndesmotic instability was confirmed before fusion. The wear of PI was documented. Results: After a mean of 63 (range, 4 – 152) months after TAR, all patients evidenced pain at the level of the syndesmosis of at least 3 months. 25 ankles (81%; 24 after posttraumatic OA) showed a widening of the syndesmotic space and 22 ankles (71%) of the medial clear space with lateral translation of the talus. The PI was seen to overlap the tibial component in 15 ankles (48%). Nine ankles (29%) evidenced cyst formation, and eight ankles (26%) showed a decrease in height of the PI; whereas, in 3 ankles (10%) a fracture of the PI was found. A valgus misalignment of the heel was found in 25 ankles (81%), a valgus TAS in 16 (52%) and a varus TAS in 11 ankles (36%). Conclusion: A syndesmotic instability after a three-component TAR apparently occurred mostly after posttraumatic OA, in particular if the heel was left in valgus. If the talus starts to move lateralward, the PI seems to be at risk for increased wear and finally mechanical failure (Figure 1). Therefore, a valgus misaligned heel should always be corrected during TAR implantation. If there is any sign of syndesmotic instability, a fusion should be considered. Further studies must proof whether in cases with a syndesmotic instability the use of a two-component design will be superior, as it stabilizes the talus in the coronal plane

Subtalar and naviculocuneiform fusion for extended breakdown of the medial arch

Combined subtalar and naviculocuneiform fusion was successful in restoring the longitudinal medial arch after extended breakdown while preserving the talon avicular joint. This surgical technique was shown to give a reliable fusion and biomechanically stable position of the foot. In this review article, we summarize the medial column procedures for flatfoot deformity and present our surgical technique and results of 10 consecutive patients treated with this method at a minimum 1-year follow-up

Standard transgluteal versus minimal invasive anterior approach in hip arthroplasty: a prospective, consecutive cohort study

A minimally invasive anterior approach (MIS) was compared to a standard lateral approach in primary total hip arthroplasty. Clinical and radiological outcomes were analyzed 6 weeks, 12 weeks, one year and two years after surgery. The duration of surgery was longer, mobility one week after surgery was better and time of hospitalization was shorter for minimally invasive-treated patients. They had less pain during movement, limping, better Harris Hip Score and satisfaction after 6 weeks, which remained after 12 weeks and 1 year, but not after two years. There were two deep infections in the MIS group. Radiological results were not affected. The infections might be a point of concern, but there were no other disadvantages of the MIS approach. In fact, early rehabilitation was facilitated and clinical results were improved. Our results encourage the continuous use of the MIS anterior approach instead of the lateral approach

Subtalar and Naviculocuneiform Fusion in Treating Adult Acquired Flatfoot Deformity with Medial Arch Collapse at the Level of the Naviculocuneiform Joint

Category: Midfoot/Forefoot Introduction/Purpose: A conflicting problem in treating acquired flatfoot deformities is the break-down of the arch at the naviculocuneiform (NC) joints. After having encountered problems with extended triple fusion, in particular increased stiffness of the foot, we established a rational to combine subtalar (ST) fusion with NC I-III fusion while preserving the talonavicular (TN) and calcaneo-cuboidal (CC) joint. Our hypothesis was that the break-down of the arch at the NC joint can be specifically addressed while sparing the Chopart Joint (TN and CC joint). This, in turn, will allow the patient to accommodate better to the ground while walking. The aim of the study was to analyze the radiographic correction and fusion rate, and to determine patient’s satisfaction with this procedure. Methods: Between 2009 and 2015, a consecutive series of 34 feet in 31 patients (female, 23; male, 8; age 67 [45-81] years) were treated by combining a fusion of the subtalar joint with a NC fusion. Both joints were exposed through a medial approach. Two 7.5mm-screws were used for ST fusion, and two 5.5mm-screws were used for NC fusion. In addition an anatomically contoured plate was used as a medio-plantar tension bending support of the NC joint. In 15 patients, an additional medial sliding-osteotomy was done to fully correct valgus misalignment of the hindfoot. The following measures were taken on standard weight-bearing radiographs including hindfoot alignment view preoperatively and at 2 years: the talus-first metatarsal angle, the talocalcaneal angle, the calcaneal pitch, the talonavicular coverage angle, the talus-first metatarsal angle, and calcaneal offset. Bony fusion was confirmed on plain radiographs. If no trabeculation was visible, a CT scan was performed. Results: All radiographic parameters, except the calcaneal pitch, showed a statistically significant improvement (Table 1). Solid fusion at the arthrodesis site was observed between 8 and 12 weeks in all but 2 cases (94.1%). One nonunion occurred at the ST joint and one at the NC joint. No interventions were necessary as both cases were asymptomatic. One patient developed an avascular necrosis of the lateral talus with need for a total ankle replacement after one year. All patients were satisfied with the results of this procedure and stated that they would undergo the surgery again. All patients were able to wear normal shoes without insoles. Conclusion: Our results show that a combined fusion of the subtalar and NC joint is an effective and safe technique in treating the adult acquired flatfoot with collapse of the medial arch at the level of the NC joint. The deformity was corrected in all three planes. Even though the TN joint was not fused, its subluxation was significantly reduced. Although our radiographic results are promising, a clinical follow-up study is necessary to quantify the clinical benefit of this procedure

Subtalar Joint Arthritis After Total Ankle Replacement

Category: Ankle Arthritis Introduction/Purpose: It has been shown that total ankle replacement (TAR) is effective in reducing pain and maintaining function in posttraumatic ankle osteoarthritis (OA). Compared to ankle fusion, TAR restores hindfoot kinematics more physiological. However, the assumption that the maintenance of ankle motion has a protective effect on the subtalar joint is still a matter of debate. Only a scarce number of long-term studies exist to support this statement.The purpose of this study was (1) to evaluate to which extent the integrity of the subtalar joint can be preserved by treating patients with a TAR, (2) to determine the rate of subtalar fusion following TAR, and (3) to determine whether the need of subsequent subtalar fusion was predictable at time of TAR. Methods: A consecutive series of 1140 primary TAR (508 female, 632 male, median age 63.5 years), performed between May 2000 and December 2015, were prospectively documented. The indication for TAR was posttraumatic OA in 78%, primary and systemic OA in 10% each, and other secondary OA in 3% of the cases. 199 subtalar joints were either fused before (n=73) or during TAR surgery (n=126), leaving 941 subtalar joints available for analysis. Radiographs before implantation and at latest follow-up were classified using the Kellgren and Lawrence Grading Score (KLS). In case of a subtalar fusion, the radiograph prior to the fusion was classified. Results: After a median radiographic follow-up of 6.1 years, the KLS remained unchanged in 66% of all cases. While it was increased by one stage in 30%, it was increased by two stages in 3%; whereas, signs of OA decreased by one stage in 1%. Cases with an increase of two stages on the KLS had a longer follow-up compared to cases without increase (p=0.047).37 cases (3.9%) underwent a subtalar joint fusion, of which the indication was progressive OA in 19 cases (51%), instability in 10 cases (27%) and others in 8 cases (22%). Subtalar joints that required a fusion after TAR did not show higher preoperative KLS than the group which did not need a subtalar joint fusion. Conclusion: Apparently, TAR protects the subtalar joint from secondary degeneration, as found in 67% with no increase in KLS. Although 33% showed an increase in the KLS, only 2% required a subtalar fusion due to progressive OA. Overall, the rate of subtalar joint fusion after TAR was low and comparable to the rates reported in the literature. Subtalar joints requiring fusion after TAR did not show higher preoperative rates of OA. Therefore, the KLS classification of subtalar OA on conventional radiographs provides only limited information about the need for postoperative subtalar fusion, and thus need to be interpreted with caution

Ligament Balancing During TAR in Varus Deformity by Open Wedge Osteotomy of the Medial Malleolus

Category: Ankle Arthritis Introduction/Purpose: After reducing the tilted talus during total ankle replacement (TAR) in severe varus deformities, the surgeon is faced to a contract medial joint and an abducted medial malleolus leaving a wide gutter. A sliding osteotomy will release the deltoid ligament but the “horizontal” position of the medial malleolus remains and bony containment of the ankle joint is not restored. We propose an open wedge osteotomy, which will both lengthen and adduct the medial malleolus and restore ligament balancing. Fixation is done by either screw or plate fixation. We present our primary results with this new technique. Methods: From 2008-2015 Total Ankle Replacement combined with open wedge medial malleolar osteotomy was done in 50 ankles (48 patients). Inclusion criteria: Takakura stages 3 and 4 ankle arthritis. Minimum follow-up was defined as one year. Results: Neutral alignment was achieved in all ankles at last follow-up. AOFAS score increased from 36 preoperative to 82 at last follow-up. In 15 Ankles an additional bony procedure was done during the TAR surgery (Calcaneus Osteotomy: 5, Dorsiflexion Osteotomy of first ray: 6, Fibula Osteotomy: 4, peritalar fusion: 4) Complications included one non-union of the medial malleolus, which resolved after revision. One deep infection that was treated in a staged procedure with reimplantation of a TAR and no recurrence of infection. Two luxations of the polyethylene due to insufficient lateral ligaments and syndesmotic dehiscence, both were stable at final follow-up after revision (ligament reconstruction and tight-rope Fixation). Conclusion: Open wedge osteotomy of the medial malleolus restores the bony containment of the ankle joint and decreases the tension of the deltoid ligament. It is a valuable tool for ligament balancing during TAR