Die Arthrodese des Subtalargelenks

Objective

Realignment and stabilization of the hindfoot by subtalar joint arthrodesis.

Indications

Idiopathic/posttraumatic arthritis, inflammatory arthritis of the subtalar joint with/without hindfoot malalignment. Optional flatfoot/cavovarus foot reconstruction.

Contraindications

Inflammation, vascular disturbances, nicotine abuse.

Surgical technique

Approach dependent on assessment. Lateral approach: Supine position. Incision above the sinus tarsi. Exposure of subtalar joint. Removal of cartilage and breakage of the subchondral sclerosis. In valgus malalignment, interposition of corticocancellous bone segment; in varus malalignment resection of bone segment from the calcaneus. Reposition and temporarily stabilization with Kirschner wires. Imaging of hindfoot alignment. Stabilization with cannulated screws. Posterolateral approach: Prone position. Incision parallel to the lateral Achilles tendon border. Removal of cartilage and breakage of subchondral sclerosis. Medial approach: Supine position. Incision just above and parallel to the posterior tibial tendon. Removal of cartilage and breakage of subchondral sclerosis. Stabilization with screws.

Postoperative management

Lower leg walker with partial weightbearing. Active exercises of the ankle. After a 6?week X?ray, increase of weightbearing. Full weightbearing not before 8 weeks; with interpositioning bone grafts not before 10–12 weeks. Stable walking shoes. Active mobilization of the ankle.

Results

Of 43 isolated subtalar arthrodesis procedures, 5 wound healing disorders and no infections developed. Significantly improved AOFAS hindfood score. Well-aligned heel observed in 34 patients; 5 varus and 2 valgus malalignments. Sensory disturbances in 8 patients; minor ankle flexion limitations. Full bone healing in 36 subtalar joints, pseudarthrosis in 4 patients.

     

Incidence and Characteristics of Atypical Femoral Fractures: Clinical and Geometrical Data

Despite the multitude of studies published on atypical femoral fractures (AFFs), a profile for patients at risk does not exist. This study aimed first at estimating AFF incidence over a 19‐month‐period in Quebec City using the ASBMR Task force criteria to define AFF. The medical records of patients hospitalized for hip or femoral fracture between June 1, 2009, and December 31, 2010, were reviewed. Thirty‐six cases of atypical fractures were identified during the 19‐month period, representing an AFF incidence of 7.0 (range, 4.7 to 9.3) cases per 100,000 person‐years. In the second part of the study, data regarding the characteristics suspected of increasing the risks of AFF were collected from medical and pharmacological records, proximal femur radiographs, and patient interviews. The data regarding each patient with an AFF during years 2008‐2011 were compared to two controls with a hip or femoral fragility fracture or a traumatic fracture, paired for age and sex. Twenty patients with AFF were added to the 36 patients with AFF selected in the first part, thereby 56 patients with AFF were investigated. The association between the occurrence of AFF and bisphosphonates (BPs) use was proven statistically significant in multivariate analysis, odds ratio (OR) = 10.39 (95% CI, 2.22 to 48.58; p = 0.0029). Compared to controls, patients with AFF had excessive femoral offset (43.1 mm versus 38.3 mm, p = 0.0007), proximal femoral neck angle in varus (128.9 degrees versus 134.0 degrees, p < 0.0001), and had greater proximal cortical thickness. This retrospective study confirms the low incidence of AFF, confirms its significant association with exposure to BPs, and reveals the possible contribution of proximal femoral geometry in AFF occurrence. © 2016 American Society for Bone and Mineral Research.     

Invariant and noninvariant natural killer T cells exert opposite regulatory functions on the immune response during murine schistosomiasis

CD1d-restricted natural killer T (NKT) cells represent a heterogeneous population of innate memory immune cells expressing both NK and T-cell markers distributed into two major subsets, i.e., invariant NKT (iNKT) cells, which express exclusively an invariant T-cell receptor (TCR) alpha chain (Valpha14Jalpha18 in mice), and non-iNKT cells, which express more diverse TCRs. NKT cells quickly produce Th1- and/or Th2-type cytokines following stimulation with glycolipid antigen (Ag) and, through this property, play potent immunoregulatory roles in autoimmune diseases, cancer, and infection. No study has addressed the role of NKT cells in metazoan parasite infections so far. We show that during murine schistosomiasis, the apparent frequency of both iNKT cells and non-iNKT cells decreased in the spleen as early as 3 weeks postinfection (p.i.) and that both populations expressed a greater amount of the activation marker CD69 at 6 weeks p.i., suggesting an activated phenotype. Two different NKT-cell-deficient mouse models, namely, TCR Jalpha18-/- (exclusively deficient in iNKT cells) and CD1d-/- (deficient in both iNKT and non-iNKT cells) mice, were used to explore the implication of these subsets in infection. We show that whereas both iNKT and non-iNKT cells do not have a major impact on the immune response during the early phase (1 and 4 weeks) of infection, they exert important, although opposite, effects on the immune response during the acute phase of the disease (7 and 12 weeks), after schistosome egg production. Indeed, iNKT cells contribute to Th1 cell differentiation whereas non-iNKT cells might be mostly implicated in Th2 cell differentiation in response to parasite Ag. Our findings suggest, for the first time, that helminths activate both iNKT and non-iNKT cells in vivo, enabling them to differentially influence the Th1/Th2 balance of the immune response.     

Use of a case-mix approach to study the trends in the incidence of second primary cancers

Purpose

To analyze trends in second primary cancer (SPC) incidence by using a case-mix approach to standardize on first cancer site distribution.