A New Digital Preoperative Planning Method for Total Hip Arthroplasties

Preoperative templating is an important part of a THA. The ability to accurately determine magnification of the hip on the radiograph and apply identical magnification to the radiograph and template will improve accuracy of preoperative templating of THA. We designed a templating method using a new way of determining the hip magnification with a linear relationship between magnification of the hip and the reference object on top of the pubis symphysis; the relationship was determined on 50 radiographs. We then compared our method with two other templating methods: an analog method assuming an average hip magnification of 15% and a digital method determining the hip magnification with a one-to-one relationship between the reference object and the hip. All methods were reproducible. Uniform undersizing occurred when templating with the digital method based on the one-to-one relationship; the analog method best predicted the implanted prosthesis size, closely followed by our new digital templating method; the new method will be particularly applicable for preoperative THA when analog methods are replaced by digital methods

Changes in immunolocalisation of ?-dystroglycan and specific degradative enzymes in the osteoarthritic synovium

OBJECTIVE: To investigate the immunolocalisation of ?-dystroglycan (?-DG) and specific matrix metalloproteinases (MMPs)-3, -9, -13 and a disintegrin like and metalloproteinase thrombospondin type 1 motif 4 (ADAMTS-4) within the joint tissues of patients with osteoarthritis (OA) and unaffected controls. DESIGN: Cartilage, synovium and synovial fluid were obtained from the hip joints of five osteoarthritic (patients undergoing total hip replacement) and five control hip joints (patients undergoing hemiarthroplasty for femoral neck fracture). The samples were analysed for ?-DG protein using Western blot technique and by immunohistochemistry for tissue distribution of ?-DG, MMP-3, -9, -13, and ADAMTS-4. RESULTS: ?-DG was detected in the smooth muscle of both normal and osteoarthritic synovial blood vessels. Importantly, ?-DG was detected in endothelium of blood vessels of OA synovium, but not in the control endothelium. In the endothelium of osteoarthritic synovial blood vessels, ?-DG co-localised with MMP-3 and -9. MMP-13 and ADAMTS-4 showed no endothelial staining, and only weak staining of the vascular smooth muscle was found. In contrast, we did not detect ?-DG protein in cartilage or synovial fluid. CONCLUSIONS: ?-DG has been shown to have a role in angiogenesis, and our results demonstrate for the first time that there are clear differences in ?-DG staining between OA and control synovial blood vessels. The specific immunolocalisation of ?-DG within endothelium of inflamed OA blood vessels and its co-localisation with MMP-3 and -9, reported to have pro-angiogenic roles and believed to be involved in ?-DG cleavage, may also suggest that ?-DG plays a role in angiogenesis accompanying OA

Long-term clinical results of the Oxford medial unicompartmental knee arthroplasty

The purposes of this study were to investigate the mode of failure and survivorship of an independently performed series of medial Oxford unicompartmental knee arthroplasties. The study included 43 knees in 40 patients with a mean follow-up of 14.88 years: 13 knees (11 patients) had revision surgery (30%), and ten patients required conversion to total knee prosthesis. The mean International Knee Society (IKS) scores at the time of the revision were 145.52 [standard deviation (SD): 39.90, range: 167–200]. The overall alignment of the knee was restored to neutral, with a hip-knee-ankle (HKA) angle average of 178° (SD: 3.21°, range: 170–186°). Survivorship, as defined by an endpoint of failure for any reason, showed that the survival rate at five years was 90%, at ten years 74.7% and at 15 years 70%. Excluding inappropriate patient selection and surgeon-associated failures, our survival analysis plot is much improved: survivorship at five years is 94.5%, at ten years 85.7% and at 15 years 80.4%. The Oxford meniscal bearing arthroplasty offers long-term pain relief with good knee function. Unfortunately, we demonstrated a high complication rate, with some of the failures encountered indicating that the surgical technique is very demanding