Mid-term results of acetabular reconstruction using a Kerboull-type acetabular reinforcement device

Purpose  

The purpose of this study was to investigate the mid-term results of 32 acetabular reconstructions performed using a Kerboull-type acetabular reinforcement device and bone graft between June 1997 and January 2009.     

Use of cementless acetabular component with a hook and iliac flanges in revision arthroplasty for massive acetabular defect

Background  

Revision hip arthroplasty of massive acetabular defect, severe combined defect, or pelvic discontinuity is challenging. The purpose of this study was to determine the midterm outcome and survivorship of a new revision technique using cementless acetabular cup supplemented with a hook and three iliac flanges in massive acetabular defects.     

Measuring acetabular dysplasia in plain radiographs

Background  

Several radiologic parameters have been used to qualify an acetabular coverage in studies determining whether an association exists between acetabular dysplasia and osteoarthritis of hip. However, it is not known which parameter is optimum for these epidemiologic studies. We evaluate the reliability, validity, and robustness of the radiologic parameters of acetabular coverage used in these studies.     

Acetabular tilt correlates with acetabular version and coverage in hip dysplasia

Background  

The rotational position of the acetabulum to the pelvis (acetabular tilt) may influence acetabular version and coverage of the femoral head. To date, the pathologic significance of acetabular tilt in hip dysplasia is unknown.     

Comparison of cement pressurisation in flanged and unflanged acetabular cups

Background  

This biomechanical study examined difference in cement pressures generated by flanged and unflanged acetabular cups in hip arthroplasty.     

Cementless acetabular revision: past, present, and future

Background  

Acetabular revision is probably the most difficult aspect of hip reconstructive surgery. Although the majority of acetabular revisions can be performed using an uncemented hemispherical acetabular device with ancillary fixation, patients with severe acetabular deficiencies and poor bone quality require more complex alternatives for revision. The limitations of traditional cementless acetabular implants has promoted the development of improved methods of fixation and revision techniques. Highly porous metals have been introduced for clinical use in arthroplasty surgery over the last decade. Their higher porosity and surface friction are ideal for acetabular revision, optimising biological fixation. The use of trabecular metal cups in acetabular revision has yielded excellent clinical results.     

Ultrasound-based computer navigation of the acetabular component: a feasibility study

Introduction  

This feasibility study investigated the accuracy of anterior pelvic reference plane (APP) registration and acetabular cup orientation in two cadavers with different BMIs.     

A comparative study of the posterolateral and anterolateral approaches for isolated acetabular revision

Purpose  

Although isolated revision of the acetabular component has become an increasingly common option for revision hip surgery, opinions differ regarding the ideal surgical approach for reducing postoperative instability. The purpose of this study was to compare the clinical and radiographic results of isolated acetabular revision performed using a posterolateral and an anterolateral approach.     

Crossover sign after rotational acetabular osteotomy for dysplasia of the hip

Background  

This study was performed to evaluate whether the radiographic crossover sign influences the painful femoroacetabular impingement or the radiographic progression of osteoarthritis after rotational acetabular osteotomy (RAO).     

Impaction bone grafting for acetabular reconstruction: mean 5.5-year results in Japanese patients

Introduction  

We performed a retrospective outcome study on 23 consecutive acetabular reconstructions involving impaction bone grafting in Japanese patients.     

Effect of periacetabular osteotomy for acetabular dysplasia clarified by three-dimensional finite element analysis

Background  

Finite element analysis (FEA) has been applied for the biomechanical analysis of acetabular dysplasia, but not for biomechanical studies of periacetabular osteotomy (PAO) or those performing analysis taking into consideration the severity of acetabular dysplasia. This study aimed to perform biomechanical evaluation of changes in stress distribution following PAO and to determine the effect of the severity of developmental dysplasia of the hip (DDH) using three-dimensional FEA.     

Complete acetabular cup revision versus isolated liner exchange for polyethylene wear and osteolysis without loosening in cementless total hip arthroplasty

Introduction  

Revision surgery in patients showing polyethylene wear and acetabular osteolysis without visible acetabular cup loosening involves the difficult decision of whether to revise only the liner or both the cup and the liner. The purpose of this study is to compare the outcomes of complete acetabular revision and isolated liner exchange in patients showing wear and osteolysis without loosening.     

Press-fit cementless acetabular fixation with and without screws

Purpose

Cementless acetabular fixation for total hip arthroplasty (THA) is widely used. The question of using screws for a better primary and secondary acetabular fixation has been discussed in the literature in recent years. The aim of this meta-analysis was to compare fixation of acetabular cups with and without screws in total hip arthroplasty.

Methods

Electronic databases Embase, PubMed and Cochrane Library were used to search for randomised controlled trials reported through May 2013 of cementless acetabular fixation for THA with and without screws. Two independent reviewers assessed the trials for eligibility and quality. All related data matching our standards were abstracted for meta-analysis by RevMan 5.0. Evaluation criteria included revisions, migration and osteolysis.

Results

A total of 1,130 THAs enrolled into five trials were included in this meta-analysis. All studies compared fixation of acetabular cups with and without screws, and our pooled data showed no statistical significance between the two surgical methods in revision, migration and osteolysis.

Conclusion

There is no significant difference between cementless acetabular fixation for THA with and without screws in revisions, migration or osteolysis.     

Single column locking plate fixation is inadequate in two column acetabular fractures. A biomechanical analysis

Background  

The objective of this study was to determine whether one can achieve stable fixation of a two column (transverse) acetabular fracture by only fixing a single column with a locking plate and unicortical locking screws. We hypothesized that a locking plate applied to the anterior column of a transverse acetabular fracture would create a construct that is more rigid than a non-locking plate, and that this construct would be biomechanically comparable to two column fixation.     

Pubic/ischial stress fractures after eccentric rotational acetabular osteotomy

Background  

Although there have been several reports on the complications of periacetabular osteotomy, stress fractures occurring in the pubic and ischial bones are less well recognised. The purpose of this study was to analyse the incidence of stress fracture, factors and treatment outcomes of stress fractures in the pubic/ischial bone after eccentric rotational acetabular osteotomy (ERAO).     

Computed tomographic measurement of acetabular and femoral component version in total hip arthroplasty

Purpose

The purposes of the present study were (1) to investigate the variation and accuracy of both acetabular and femoral component version on the axial computed tomographic (CT) images, and (2) to better define the associations between the components version and clinical factors.

Methods

We investigated acetabular and femoral component orientation in 1,411 primary total hip arthroplasties that had been performed without computer-assisted navigation. Version of the acetabular and femoral components was measured on the axial CT images.

Results

The component version was significantly greater than the native version in both acetabular and femoral version. There was a significant correlation between the stem and native femoral versions, but not between the acetabular component and native acetabular versions.

Conclusion

This study identifies several features that might help analyse the effect of pre-operative native acetabular and femoral version on the variation of component alignment.     

Modular acetabular reconstructive cup in acetabular revision total hip arthroplasty at a minimum ten year follow-up

Purpose

Modular acetabular reconstructive cups have been introduced in an attempt to offer initial rigid fixation by iliac lag screws and ischial pegs, to support bone grafts with a flanged metal socket, and to restore original hip center in acetabular revision. The purpose of this study was to clarify minimum ten year follow-up results of this cup system with morsellised allografts in revision cases.

Methods

We retrospectively investigated 54 acetabular revisions at a mean of 11 years (range, ten to 14 years). The indications were Paprosky’s type 2B (eight hip), 2C (eight hips), 3A (23 hips), 3B (nine hips), and 4 (six hips).

Results

Using aseptic loosening as the endpoints, the survival rate was 89.3 % (95 % CI 81–98). Radiographically, one type 3A hip, three type 3B hips and one type 4 hip showed aseptic loosening while no type 2 hips or no cemented cups showed loosening.

Conclusions

The modular reconstructive cups for acetabular revision showed bone stock restoration and stable implantation.     

Excessive polyethylene wear and acetabular bone defects from standard use of a hooded acetabular insert in total hip arthroplasty

Purpose

In total hip arthroplasty (THA) the use of a polyethylene (PE) insert with a hooded rim can be considered to reduce dislocation risks. This benefit has to be balanced against the potential introduction of impingement of the femoral component on this rim. We present a case series of early acetabular revisions for excessive PE wear and acetabular bone defects from overuse of such a hooded rim insert.

Material and methods

Twenty-eight patients with 34 consecutive early acetabular revisions were evaluated on failure mechanism. One type of implant was used in all cases. Standard pelvic radiographs and pre-operative CT scans were used to quantify PE wear, implant positioning and acetabular bone defects.

Results

An acetabular revision with impaction grafting was performed in all cases with a mean cup survival of ten years (range 1.3–19.3). No concurrent stem revisions were necessary. Overall implant positioning was adequate with a mean cup inclination of 45° (range 39–57) and anteversion of 25° (range eight to 45). The mean PE wear was 0.24 mm/year (range 0.00–1.17). The mean acetabular bone defect on pelvic CT scans was calculated as 352 mm² (range zero to 1107) and 369 mm² (range zero to 1300) in the coronal and transversal planes, respectively. A hooded acetabular insert was retrieved in all cases and profound PE wear, typically from the posterior hooded rim, was encountered.

Conclusion

The use of hooded acetabular inserts may be considered to improve implant stability intra-operatively. This case series clearly presents that together with these devices, component impingement with concordant complications such as accelerated PE wear may be introduced. Standard use of these stabilizing inserts should thus be avoided.     

Three-dimensional in vivo difference between native acetabular version and acetabular component version influences iliopsoas impingement after total hip arthroplasty

Purpose

The potential influence of acetabular component orientation on iliopsoas impingement in total hip arthroplasty (THA) has not been previously quantified. The aim of the present study was to utilize pre- and post-operative CT-based 3D models to quantify iliopsoas impingement on acetabular components, and to identify any potential factors associated with iliopsoas impingement.

Methods

Iliopsoas muscle was modelled from pre-operative CT scans and transferred to the post-operative 3D models in 19 THAs. The volume and the area of the overlap between iliopsoas muscle and acetabular cup (iliopsoas volume & area) was measured on axial and sagittal images. Most protruded lengths of cup uncovered by acetabular bone were measured on axial sagittal scan of CT scans. Version of acetabulum, acetabular cup, and the difference between the two (version difference) were also measured with cup inclination and size. Linear regression analysis was performed to identify any factor influencing iliopsoas impingement.

Results

Iliopsoas impingement volume and area were 100.6?±?226.1 (range, 0.0–663.9) mm³ and 52.6?±?102.0 (0.0–342.3) mm³, respectively. The protruded lengths on axial and sagittal view were 6.9?±?5.3 (0.0–16.0) and 2.1?±?2.7 (0.0–8.0). Linear regression model showed that version difference was significantly related to the iliopsoas impingement volume and area (beta?=??0.709, p?=?0.041 for volume, and beta?=??0.684, p?=?0.047 for area).

Conclusions

The results of this study demonstrate that iliopsoas impingement on acetabular components was influenced by the version difference between pre-operative acetabular bone and acetabular component rather than the magnitude of post-operative cup version alone.

     

Direct comparison of polyethylene wear in cemented and uncemented acetabular cups

Background  

It has been indicated that, in the long term, the rate of wear and the degree of osteolysis observed with uncemented acetabular components are greater than those associated with cemented cups, but most studies which compare the wear characteristics of cementless with cemented cups have used historical controls. We report a direct comparison of wear of a cemented and an uncemented cup with similar design, polyethylene, and sterilization method.