Correlation of intra-articular ankle pathology with cytokine biomarkers and matrix degradation products.

BACKGROUND: Articular cartilage degeneration is mediated by inflammatory cytokines and fragments of structural matrix proteins. Few studies have examined the role of these biomarkers in intra-articular pathology of the ankle. METHODS: Four groups of patients with increasing ankle pathology were enrolled. Group 1 included controls with no pain who underwent unrelated forefoot surgery. Group 2 included patients undergoing arthroscopy with intraoperative mild chondrosis. Group 3 included patients undergoing arthroscopy with moderate/severe chondrosis, osteochondral lesions, impingement, or loose bodies. Group 4 included positive controls with severe arthrosis undergoing ankle arthrodesis/arthroplasty. Ankle fluid was obtained by intra-articular aspiration and was assayed for IL-6, IFN-γ, MCP, MIP-1ß, and fibronectin-aggrecan complex (FAC), a matrix-degradation marker. There were 36 patients total, 21 males and 15 females with a mean age 45 (±16; range 18 to 76) years and a mean VAS for pain of 4.7 (±3.5; range 0 to 9). In groups 1 through 4, there were 11, 6, 15 and 4 patients respectively. RESULTS: The mean values of MCP-1 were 49.8 (±8.0) for minimal pathology and 133.9 (±33.0) for substantial pathology (pg/ml). The mean values of the FAC were 2.83 (±1.16) for minimal pathology and 9.62 (±2.23) for substantial pathology (optical density at 450 nm). The groups differed significantly in age, preoperative VAS, FAC, IL-6, and MCP-1 (p<0.05). CONCLUSION: There are differences in FAC and MCP-1 with increasing grades of severity of intra-articular pathology. CLINICAL RELEVANCE: These tests may play a role in determining the necessity for arthroscopy or intra-articular procedures in equivocal candidates.

Eight-year results of a minimally constrained total ankle arthroplasty.

BACKGROUND: Few studies have reported the intermediate to long-term results of minimally constrained total ankle replacements. The purpose of this study was to investigate the efficacy and safety of a minimally constrained total ankle prosthesis in a select low-demand patient population. METHODS: We reviewed a consecutive series of patients with rheumatoid arthritis who underwent a Buechel-Pappas total ankle replacement (BP TAR) between 1990 to 1997. Thirty-one ankle arthroplasties were performed in 23 patients with rheumatoid arthritis. One patient was lost to followup (deceased) and two ankles that failed resulted in fusion (overall survivorship - 93%). This left 28 ankles (21 patients) that were re-evaluated clinically and radiographically with an average followup of 8.3 (range 5.0 to 12.2) years. Preoperative and postoperative ranges of motion were measured and AOFAS hindfoot scores were calculated. Recent weightbearing radiographs were reviewed for evidence of component subsidence, radiolucent lines, and osteolysis. RESULTS: In 25 of 28 ankles (89%), patients were completely satisfied with the result of their ankle replacement and rated their pain as only mild to none; three (11%) patients were dissatisfied. Radiographic analysis revealed stable, well-positioned implants with evidence of biologic ingrowth in 23 ankles (82%), while five implants were interpreted as being at risk for impending failure because of marked tibial or talar component subsidence (18%). Component subsidence did not correlate with the presence or absence of radiolucent lines. Only one ankle demonstrated clear evidence of osteolysis. Ten intraoperative medial malleolar fractures occurred (32% of ankles) during implantation of the prosthesis, though in only one did this adversely affect patient outcome. Nine postoperative complications (29%) occurred; four wound dehiscences, four stress fractures, and one medial malleolar nonunion. CONCLUSIONS: Improvements in prosthetic design such as cementless fixation and decreased constraint appear to make total ankle arthroplasty a more predictable procedure over this period of followup. Despite a variety of complications, we are encouraged by the intermediate-term results in a select low-demand arthritic population.