Iliac crest bone graft harvesting complications: A case of liver herniation

SummaryThe iliac crest is an easily accessible donor site offering a relatively large and safe supply of bone. There are however possible complications; residual pain frequently, and more rarely herniation. This latter's true incidence is unknown in a literature review, which found 15 articles. We report a case of liver herniation in a 64-year-old overweight lady after harvesting bone from her iliac crest. The clinical diagnosis was confirmed by CT scan. Despite an appropriate surgical repair, the hernia recurred. This serious complication of bone harvesting from the iliac crest, and possible other undesirable events described, prompted reconsideration of our harvesting techniques, and the use in our unit of bone substitutes or cell therapy to fill bone defects

Ceramic on ceramic bearing fractures in total hip arthroplasty : an analysis of data from the national joint registry

Aims: Ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry (NJR). Patients and Methods: We analysed data on 111,681 primary CoC THA’s and 182 linked revisions for bearing fracture recorded in NJR. We used implant codes to identify ceramic bearing composition and generated Kaplan-Meier estimates for implant survivorship. Logistic regression analyses were performed for implant size and patient specific variables to determine any associated risks for revision. Results: 99.8% of bearings were CeramTec Biolox® products. Revisions for fracture were linked to 7 of 79,442 (0.009%) Biolox® Delta heads, 38 of 31,982 (0.119%) Biolox® Forte heads, 101 of 80,170 (0.126%) Biolox® Delta liners and 35 of 31,258 (0.112%) Biolox® Forte liners. Regression analysis of implant size revealed smaller heads had significantly higher odds of fracture (χ2=68.0, p<0.0001). The highest fracture risk were observed in the 28mm Biolox® Forte subgroup (0.382%). There were no fractures in the 40mm head group for either ceramic type. Liner thickness was not predictive of fracture (p=0.67). BMI was independently associated with revision for both head fractures (OR 1.09 per unit increase, p=0.031) and liner fractures (OR 1.06 per unit increase, p=0.006). Conclusions: We report the largest study of CoC bearing fractures to date. The risk of revision for CoC bearing fracture is very low, however previous studies have underestimated this risk. There is good evidence that the latest generation of ceramic has greatly reduced the odds of head fracture but not of liner fracture. Small head size and high patient BMI are associated with an increased risk of ceramic bearing fracture

Basic Science Considerations in Primary Total Hip Replacement Arthroplasty

Total Hip Replacement is one of the most common operations performed in the developed world today. An increasingly ageing population means that the numbers of people undergoing this operation is set to rise. There are a numerous number of prosthesis on the market and it is often difficult to choose between them. It is therefore necessary to have a good understanding of the basic scientific principles in Total Hip Replacement and the evidence base underpinning them. This paper reviews the relevant anatomical and biomechanical principles in THA. It goes on to elaborate on the structural properties of materials used in modern implants and looks at the evidence base for different types of fixation including cemented and uncemented components. Modern bearing surfaces are discussed in addition to the scientific basis of various surface engineering modifications in THA prostheses. The basic science considerations in component alignment and abductor tension are also discussed. A brief discussion on modular and custom designs of THR is also included. This article reviews basic science concepts and the rationale underpinning the use of the femoral and acetabular component in total hip replacement

Total hip replacement: increasing femoral offset improves functional outcome

INTRODUCTION: The aim of this study was to assess the independent effect of radiographic measures of implant position, relative to pre-operative anatomical assessment, on the functional outcome of total hip arthroplasty according to change in the Oxford hip score (OHS) 1 year post surgery. METHODS: A prospective cohort study was preformed to assess whether improvement in functional outcome (change in OHS at 1 year) and the relationship with femoral offset and length, and acetabular offset and height. After a power calculation 359 patients were recruited to the study and radiographic measures were performed by blinded observers. Regression analysis was used to assess the independent effect of the four radiographic measurements after adjusting for confounding variables. RESULTS: There was a significant (p < 0.001) decrease in acetabular offset [5.3 mm, 95 % confidence interval (CI) 4.4–6.2] and increase in femoral offset (6.1 mm, 95 % CI 5.4–6.8). Hence there was no significant change in overall offset. Femoral offset was the only radiographic measure to be achieved statistical significance (r = 0.198, 95 % CI 0.063–0.333, p = 0.004) in relation to clinical outcome, with increasing offset being associated with a greater improvement in the OHS. On combining femoral and acetabular offset increasing offset was associated with a greater improvement in the OHS (r = 0.10, 95 % CI 0.01–0.19, p = 0.04). CONCLUSION: This study supports the long-held biomechanical theory of medialisation of the acetabular component with compensatory increased femoral offset results in improved functional outcome

Reproducing Proximal Femur Anatomy with Custom Stems.

International audienceAn accurate 3D reconstruction of the hip is mandatory to enhance clinical outcomes and to help increasing the implants life expectancy. These goals may be difficult to achieve in some patients with outlier anatomy. Custom stem technology is a reliable solution to treat degenerated hip patients having such an atypical hip anatomy. In our practice 12% of patients require a custom stem to achieve an accurate reconstruction of their proximal femur anatomy. Performing 3D planning for all osteoarthritic hip patients and checking intraoperative anatomical parameters are key steps to anticipate the surgical difficulties, select the appropriate implants, and restore normal hip biomechanics