Bernd Ishaque

Closing-wedge high tibial osteotomy: survival and risk factor analysis at long-term follow up

BackgroundClosing-wedge high tibial osteotomy (HTO) is successful for the treatment of medial osteoarthritis with varus malalignment. Preoperative risk factors for HTO failure are still controversial. The aim of this study was to elucidate the outcome and assess the influence of risk factors on long term HTO survival.Methods199 patients were retrospectively studied with a mean follow-up period of 9.6 years after HTO. HTO failure was defined as the need for conversion to TKA. Survival was analyzed with the Kaplan-Meier method. Knee function was evaluated by the Hospital for Special Surgery (HSS) score. HTO-associated complications were also assessed. Univariate, multivariate, and logistic regression analysis were performed to evaluate the influence of age, gender, BMI, preoperative Kellgren-Lawrence osteoarthritis grade, and varus angle on HTO failure.Results39 complications were recorded. Thus far, 36 HTOs were converted to TKA. The survival of HTO was 84% after 9.6 years. Knee function was considered excellent or good in 64% of patients. A significant preoperative risk factor for HTO failure was osteoarthritis, Kellgren-Lawrence grade >2.ConclusionHTO provides good clinical results in long-term follow-up. Preoperative osteoarthritis Kellgren-Lawrence grade >2 is a significant predictive risk factor for HTO failure. Results of HTO may be improved by careful patient selection. Complications associated with HTO should not be underestimated.

Articular Joint Lubricants during Osteoarthritis and Rheumatoid Arthritis Display Altered Levels and Molecular Species

Background Hyaluronic acid (HA), lubricin, and phospholipid species (PLs) contribute independently or together to the boundary lubrication of articular joints that is provided by synovial fluid (SF). Our study is the first reporting quantitative data about the molecular weight (MW) forms of HA, lubricin, and PLs in SF from cohorts of healthy donors, patients with early (eOA)- or late (lOA)-stage osteoarthritis (OA), and patients with active rheumatoid arthritis (RA). Methods We used human SF from unaffected controls, eOA, lOA, and RA. HA and lubricin levels were measured by enzyme-linked immunosorbent assay. PLs was quantified by electrospray ionization tandem mass spectrometry. Fatty acids (FAs) were analyzed by gas chromatography, coupled with mass spectrometry. The MW distribution of HA was determined by agarose gel electrophoresis. Results Compared with control SF, the concentrations of HA and lubricin were lower in OA and RA SF, whereas those of PLs were higher in OA and RA SF. Moreover, the MW distribution of HA shifted toward the lower ranges in OA and RA SF. We noted distinct alterations between cohorts in the relative distribution of PLs and the degree of FA saturation and chain lengths of FAs. Conclusions The levels, composition, and MW distribution of all currently known lubricants in SF—HA, lubricin, PLs—vary with joint disease and stage of OA. Our study is the first delivering a comprehensive view about all joint lubricants during health and widespread joint diseases. Thus, we provide the framework to develop new optimal compounded lubricants to reduce joint destruction.

Fatigue Fracture of a Short Stem Hip Replacement: A Failure Analysis With Electron Microscopy and Review of the Literature

Four years after primary implantation of an ESKA Cut short-stemmed prosthesis, a 61-year-old patient suffered fracture of the implant. The combination of missing proximal support of the prosthesis as well as enormous strain on the distal third of the stem can be considered as main reason for the fatigue failure. The special design of the modular implant with a small diameter and a spongy metal surface can be regarded as a contributing factor. This unique case demonstrates a possible failure mechanism of short- and ultra short-stemmed prostheses.

The Anterolateral Minimally Invasive Approach for Total Hip Arthroplasty: Technique, Pitfalls, and Way Out

Different approaches for the hip have been developed for minimally invasive surgery in total hip arthroplasty. The goal of minimally invasive surgery is to reduce invasiveness to skin, muscles, and bone and improve recovery time after total hip arthroplasty. This article describes the technique of a minimally invasive approach to the hip from the anterolateral direction step by step and includes preoperative settings and pitfalls.

Process optimized minimally invasive total hip replacement

The purpose of this study was to analyse a new concept of using the the minimally invasive direct anterior approach (DAA) in total hip replacement (THR) in combination with the leg positioner (Rotex- Table) and a modified retractor system (Condor). We evaluated retrospectively the first 100 primary THR operated with the new concept between 2009 and 2010, regarding operation data, radiological and clinical outcome (HOOS). All surgeries were perfomed in a standardized operation technique including navigation. The average age of the patients was 68 years (37 to 92 years), with a mean BMI of 26.5 (17 to 43). The mean time of surgery was 80 min. (55 to 130 min). The blood loss showed an average of 511.5 mL (200 to 1000 mL). No intra-operative complications occurred. The postoperative complication rate was 6%. The HOOS increased from 43 points pre-operatively to 90 (max 100 points) 3 months after surgery. The radiological analysis showed an average cup inclination of 43° and a leg length discrepancy in a range of +/− 5 mm in 99%. The presented technique led to excellent clinic results, showed low complication rates and allowed correct implant positions although manpower was saved.

Comparative lipidomic analysis of synovial fluid in human and canine osteoarthritis

OBJECTIVE The lipid profile of synovial fluid (SF) is related to the health status of joints. The early stages of human osteoarthritis (OA) are poorly understood, which larger animals are expected to be able to model closely. This study examined whether the canine groove model of OA represents early OA in humans based on the changes in the lipid species profile in SF. Furthermore, the SF lipidomes of humans and dogs were compared to determine how closely canine lipid species profiles reflect the human lipidome. METHODS Lipids were extracted from cell- and cellular debris-free knee SF from nine donors with healthy joints, 17 patients with early and 13 patients with late osteoarthritic changes, and nine dogs with knee OA and healthy contralateral joints. Lipid species were quantified by electrospray ionization tandem mass spectrometry (ESI-MS/MS). RESULTS Compared with control canine SF most lipid species were elevated in canine OA SF. Moreover, the lipid species profiles in the canine OA model resembled early OA profiles in humans. The SF lipidomes between dog and human were generally similar, with differences in certain lipid species in the phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and sphingomyelin (SM) classes. CONCLUSIONS Our lipidomic analysis demonstrates that SF in the canine OA model closely mimics the early osteoarthritic changes that occur in humans. Further, the canine SF lipidome often reflects normal human lipid metabolism.

Influence of cerclages on primary stability of tumor megaprostheses subjected to distal femur defects

BACKROUND Purpose of this experimental study was to investigate the influence of cerclages on the primary stability of the MUTARS system using distally fractured synthetic femora. METHODS 4 MUTARS prostheses were implanted in synthetic femora respectively. Groups consisted of 4 intact bones, 4 fractured with cerclages and 4 fractured bones without cerclages. Spatial micromovements were measured with a high-precision rotational setup. FINDINGS The order from the weakest to the strongest torque transmission of the intact bones was rm1-rm4-rm2-rm3 (p=0.011) and of the fractured bones with cerclages rm4-rm1-rm3-rm2 (p=0.013). The MUTARS stems broke out of the fractured femoral shaft by removing cerclages (p<0.001) and by the influence of bone defect A (p<0.001). Overall micromovements of the intact bones were lower than those of the fractured bones without cerclages (p<0.001) and overall micromovements of the fractured bones with cerclages were lower than those of bones without cerclages (p<0.001). INTERPRETATION Due to high press-fit at the proximal and distal isthmus region fissural fractures of the femur may occur. This should always be taken into account. It is advisable to secure them and provide a prophylaxis for these fissural fractures by means of cerclages.

Langfristige Analyse der Druckscheibenendoprothese

BACKGROUND Hip replacement in patients younger than 50 years old is no longer an exception in view of the increasing necessity for care. The aim of the present study was to analyze whether the results after implantation of thrust plate prosthesis (TPP) with metaphyseal anchorage are equal for patients below 50 years compared to older patients. PATIENTS AND METHODS The investigation comprised 465 TPP implantations. In 149 TPP the patient age was below 50 years (group A) und in 316 TPP cases above 50 years (group B). Clinical and radiological evaluation of the results for both groups was carried out as well as a differentiated survival analysis with defined endpoints. RESULTS Survival analysis of group A (96%/13.2 years) showed a significantly improved survival rate compared to group B (86%/12.5 years). Additionally, the risk of prosthesis and/or radiological signs loosening of was significantly lower in group A than in group B (p <0.05). CONCLUSION Comparison of long-term results of prostheses with intramedullary fixation shows that the anchorage principle of TPP with bone-saving implantation to the proximal femur is justified especially for patients below 50 years of age.

Interleukin-1β affects the phospholipid biosynthesis of fibroblast-like synoviocytes from human osteoarthritic knee joints

OBJECTIVE Phospholipids (PLs), together with hyaluronan and lubricin, are involved in boundary lubrication within human articular joints. Levels of lubricants in synovial fluid (SF) have been found to be associated with the health status of the joint. However, the biosynthesis and release of PLs within human joints remains poorly understood. This study contributes to our understanding of the effects of cytokines on the biosynthesis of PLs using cultured fibroblast-like synoviocytes (FLS) from human osteoarthritic knee joints. METHODS Cultured FLS were stimulated with IL-1β, TNFα, IL-6, or inhibitors of cell signaling pathways such as QNZ, SB203580 and SP600125 in the presence of stable isotope-labeled precursors of PLs. Lipids were extracted and quantified using electrospray ionization tandem mass spectrometry (ESI-MS/MS). RESULTS Our analyses provide for the first time a detailed overview of PL species being synthesized by FLS. IL-1β increased the biosynthesis of both phosphatidylethanolamine (PE) and PE-based plasmalogens. We show here that the NF-κB, p38 MAPK and JNK signaling pathways are all involved in IL-1β-induced PL biosynthesis. IL-6 had no impact on PLs, whereas TNFα increased the biosynthesis of all PL classes. CONCLUSION The biosynthesis of various PLs is controlled by IL-1β and TNFα. Our detailed PL species analysis revealed that FLS can partly contribute to the elevated PL levels found in human osteoarthritis (OA) SF. IL-1β in particular stimulates PE and PE-based plasmalogens which can act as cell-protective antioxidants. These results suggest that during OA progression, FLS undergo alterations in their PL composition to adapt to the new diseased environment.

[Long-term results of thrust plate prostheses: comparison of patients younger than and older than 50 years].

BACKGROUND Hip replacement in patients younger than 50 years old is no longer an exception in view of the increasing necessity for care. The aim of the present study was to analyze whether the results after implantation of thrust plate prosthesis (TPP) with metaphyseal anchorage are equal for patients below 50 years compared to older patients. PATIENTS AND METHODS The investigation comprised 465 TPP implantations. In 149 TPP the patient age was below 50 years (group A) und in 316 TPP cases above 50 years (group B). Clinical and radiological evaluation of the results for both groups was carried out as well as a differentiated survival analysis with defined endpoints. RESULTS Survival analysis of group A (96%/13.2 years) showed a significantly improved survival rate compared to group B (86%/12.5 years). Additionally, the risk of prosthesis and/or radiological signs loosening of was significantly lower in group A than in group B (p <0.05). CONCLUSION Comparison of long-term results of prostheses with intramedullary fixation shows that the anchorage principle of TPP with bone-saving implantation to the proximal femur is justified especially for patients below 50 years of age.