Aims

This study aimed to determine if macrophages can attach and directly affect the oxide layers of 316L stainless steel, titanium alloy (Ti6Al4V), and cobalt-chromium-molybdenum alloy (CoCrMo) by releasing components of these alloys.

Introduction

Porous surfaces developed over the past decades have been shown to promote tissue ingrowth. Hydroxyapatite (HA) coatings have been added to these porous coatings in an attempt to further augment bone ingrowth. The development of additive manufacturing techniques has allowed for precision in building these complex porous structures. The effect of supplemental HA coatings on these new surfaces is unclear. The purpose of this study is to evaluate the biological fixation of a novel 3D printed porous implant in a canine model. In addition, we evaluated the effect of different HA coatings on this 3D printed implant.

Aims

The purpose of this study was to evaluate the biological fixation of a 3D printed porous implant, with and without different hydroxyapatite (HA) coatings, in a canine model.

Aims. Large acetabular bone defects encountered in revision total hip arthroplasty (THA) are challenging to restore. Metal constructs for structural support are combined with bone graft materials for restoration. Autograft is restricted due to limited volume, and allogenic grafts have downsides including cost, availability, and operative processing. Bone graft substitutes (BGS) are an attractive alternative if they can demonstrate positive remodelling. One potential product is a biphasic injectable mixture (Cerament) that combines a fast-resorbing material (calcium sulphate) with the highly osteoconductive material hydroxyapatite. This study reviews the application of this biomaterial in large acetabular defects. Methods. We performed a retrospective review at a single institution of patients undergoing revision THA by a single surgeon. We identified 49 consecutive patients with large acetabular defects where the biphasic BGS was applied, with no other products added to the BGS. After placement of metallic acetabular implants, the BGS was injected into the remaining bone defects surrounding the new implants. Patients were followed and monitored for functional outcome scores, implant fixation, radiological graft site remodelling, and revision failures. Results. Mean follow-up was 39.5 months (36 to 71), with a significant improvement in post-revision function compared to preoperative function. Graft site remodelling was rated radiologically as moderate in 31 hips (63%) and strong in 12 hips (24%). There were no cases of complete graft site dissolution. No acetabular loosening was identified. None of the patients developed clinically significant heterotopic ossification. There were twelve reoperations: six patients developed post-revision infections, three experienced dislocations, two sustained periprosthetic femur fractures, and one subject had femoral component aseptic loosening. Conclusion. Our series reports bone defect restoration with the sole use of a biphasic injectable BGS in the periacetabular region. We did not observe significant graft dissolution. We emphasize that successful graft site remodelling requires meticulous recipient site preparation. Cite this article: Bone Jt Open 2022;3(12):991–997

Surgical treatment of Hip PJI by resection of the infected implants and tissue and placement of a “spacer” which elutes antibiotic via antibiotic loaded cement is an accepted treatment option. There is some controversy over whether this “spacer” should be articulating or static. Proponents of the articulating option argue that there is improved function and maintenance of the soft tissue envelop. Critics have suggested that additional biomaterials may compromise eradication of infection. This study compares our results of the 2 treatment options. A review of our institutional PJI database between 2016 and 2021 identified 87 patients who were treated with resection arthroplasty for unilateral total hip PJI. The cohort was analyzed for demographics and type for surgery, as well as medical comorbidities, survivorship, and treatment success. 44 patients were female, the mean age of all patients was 62. 44 patients were treated with Articulating apacers, and 43 patients treated with static spacers. There was no significant difference between ASA or Elixhauser score, and no significant difference between mortality or treatment failure. This study did not show any difference between the patients who receive static spacers, from those who received articulating spacers, and deomstrated similar treatment success rates. From this data there does not appear to be any difference in success rates between those patients that were treated with static spacers and those that were treated with articulating spacers

Although there is some clinical evidence of ceramic bearings being associated with a lower infection rate after total hip arthroplasty (THA), available data remains controversial since this surface is usually reserved for young, healthy patients. Therefore, we investigated the influence of five commonly-used biomaterials on the adhesion potential of four biofilm-producing bacteria usually detected in infected THAs. In this in-vitro research, we evaluated the ability of S. aureus, S. epidermidis ATCC 35984, E. coli ATCC 25922 and P. aeruginosa to adhere to the surface of solid biomaterials, including a 28mm cobalt-chromium metal head, a 28mm fourth-generation ceramic head, a 48mm fourth-generation ceramic insert, a 48mm highly-crossed linked polyethylene insert and a 52mm titanium porous-coated acetabular component. After an initial vortex step, a bacterial separation from the surface of each specimen was done until no remaining attached bacteria were observed by digital optical microscope. The colony-forming units were counted to determine the number of viable adherent bacteria and the bacterial density. We found no differences on global bacterial adhesion between the different surfaces. E. coli presented the least adherence potential among the analysed pathogens (p<0.001). The combination of E. coli and S. epidermidis generated an antagonist effect over the adherence potential of S. epidermidis individually (58±4% vs. 48±5%; p=0.007). The combination of P. aeruginosa and S. aureus presented a trend to an increased adherence of P. aeruginosa independently, suggesting an agonist effect (71% vs. 62%; p=0.07). In this study, ceramic bearings appeared not to be related to a lower bacterial adhesion than other biomaterials. However, different adhesive potentials among bacteria may play a major role on infection's inception

Aims

Total hip arthroplasty (THA) is considered the preferred treatment for displaced proximal femoral neck fractures. However, in many countries this option is economically unviable. To improve outcomes in financially disadvantaged populations, we studied the technique of concomitant valgus hip osteotomy and operative fixation (VOOF). This prospective serial study compares two treatment groups: VOOF versus operative fixation alone with cannulated compression screws (CCSs).

Porous tantalum is a highly osteoinductive biomaterial, initially introduced in orthopedics in 1997, with a subsequent rapid evolution of orthopedic applications. The use of porous tantalum for the acetabular component in primary total hip arthroplasty (THA) has demonstrated excellent short-term and mid-term results. However, long term data are scarce. The purpose of this prospective study is to report the long-term clinical and radiological outcome following use of an uncemented porous tantalum acetabular component in primary THA with a minimum follow-up of 17.5 years, in a previously studied cohort of patients. We prospectively followed 128 consecutive primary THAs in 140 patients, between November 1997 and June 1999. A press-fit porous tantalum monoblock acetabular component was used in all cases. The presence of initial gaps in the polar region, as sign of incomplete seating of the monoblock cup, was assessed on the immediate postoperative radiographs. All patients were followed clinically and radiographically at 6, 12, and 24 weeks and 12 months and then at 2, 5, 8, 10, and 19 years, for a mean of 18.1 years (range 17.5 – 19 years). Periacetabular dome gap filling, acetabular cup migration and polyethylene wear were assessed by the EBRA digital measurement system, until 2 years postoperatively. Mean age of patients at the time of operation was 60.4 years old (range 24 – 72). Harris hip score, Oxford Hip Score and range of motion (ROM) were dramatically improved in all cases (p < 0.001). In the initial postoperative radiographs, periacetabular dome gaps were observed in the 15% of cases, and were progressively filled within 6 months. In 2 years postoperatively, the mean component migration, as shown in EBRA study, was 0.67 mm. At last follow-up, all cups were radiographically stable with no evidence of migration, gross polyethylene wear, progressive radiolucencies, osteolytic lesions or acetabular fractures. The survivorship with re-operation for any reason as end point was 92.8%, whereas the survivorship for aseptic loosening as an end point was 100%. Upon visual inspection, two removed acetabular components due to recurrent dislocation and infection, respectively, showed extensive bone osseointegration. In our primary THA series, the porous tantalum monoblock cup demonstrated excellent clinical and radiographic outcomes with no failures because of aseptic loosening at a mean follow-up of 18.1 years. Porous tantalum acetabular components showed excellent initial stability, produced less wear debris and revealed a great potential for bone ingrowth. Due to its unique osteoinductive properties and elliptical shape, porous tantalum monoblock cups have demonstrated superior short and long-term survivorship compared to other press fit prostheses in the market

Aims

The aim of this study was to report the medium-term outcomes of impaction bone allograft and fibular grafting for osteonecrosis of the femoral head (ONFH) and to define the optimal indications.

Aims

In the 1990s, a bioactive bone cement (BABC) containing apatite-wollastonite glass-ceramic (AW-GC) powder and bisphenol-a-glycidyl methacrylate resin was developed at our hospital. In 1996, we used BABC to fix the acetabular component in primary total hip arthroplasty (THA) in 20 patients as part of a clinical trial. The purpose of this study was to investigate the long-term results of primary THA using BABC.

Aims

A variety of surgical approaches are used for total hip arthroplasty (THA), all with reported advantages and disadvantages. A number of common complications can occur following THA regardless of the approach used. The purpose of this study was to compare five commonly used surgical approaches with respect to the incidence of surgery-related complications.

A retrospective review was performed of patients undergoing primary cementless total knee replacement (TKR) using porous tantalum performed by a group of surgical trainees. Clinical and radiological follow-up involved 79 females and 26 males encompassing 115 knees. The mean age was 66.9 years (36 to 85). Mean follow-up was 7 years (2 to 11). Tibial and patellar components were porous tantalum monoblock implants, and femoral components were posterior stabilised (PS) in design with cobalt–chromium fibre mesh. Radiological assessments were made for implant positioning, alignment, radiolucencies, lysis, and loosening. There was 95.7% survival of implants. There was no radiological evidence of loosening and no osteolysis found. No revisions were performed for aseptic loosening. Average tibial component alignment was 1.4° of varus (4°of valgus to 9° varus), and 6.2° (3° anterior to 15° posterior) of posterior slope. Mean femoral component alignment was 6.6° (1° to 11°) of valgus. Mean tibiofemoral alignment was 5.6° of valgus (7° varus to 16° valgus). Patellar tilt was a mean of 2.4° lateral (5° medial to 28° lateral). Patient satisfaction with improvement in pain was 91%. Cementless TKR incorporating porous tantalum yielded good clinical and radiological outcomes at a mean of follow-up of seven-years.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):87–92.

Large ceramic femoral heads offer several advantages that are potentially advantageous to patients undergoing both primary and revision total hip replacement. Many high-quality studies have demonstrated the benefit of large femoral heads in reducing post-operative instability. Ceramic femoral heads may also offer an advantage in reducing polyethylene wear that has been reported in vitro and is starting to become clinically apparent in mid-term clinical outcome studies. Additionally, the risk of taper corrosion at a ceramic femoral head–neck junction is clearly lower than when using a metal femoral head. With improvements in the material properties of both modern ceramic femoral heads and polyethylene acetabular liners that have reduced the risk of mechanical complications, large ceramic heads have gained popularity in recent years.

Cite this article: Bone Joint J 2013;95-B, Supple A:63–6.

Following the recall of modular neck hip stems in July 2012, research into femoral modularity will intensify over the next few years. This review aims to provide surgeons with an up-to-date summary of the clinically relevant evidence. The development of femoral modularity, and a classification system, is described. The theoretical rationale for modularity is summarised and the clinical outcomes are explored. The review also examines the clinically relevant problems reported following the use of femoral stems with a modular neck.

Joint replacement registries in the United Kingdom and Australia have provided data on the failure rates of modular devices but cannot identify the mechanism of failure. This information is needed to determine whether modular neck femoral stems will be used in the future, and how we should monitor patients who already have them implanted.

Cite this article: Bone Joint J 2013;95-B:1011–21.

We investigated the early results of modular porous metal components used in 23 acetabular reconstructions associated with major bone loss. The series included seven men and 15 women with a mean age of 67 years (38 to 81), who had undergone a mean of two previous revisions (1 to 7).

Based on Paprosky’s classification, there were 17 type 3A and six type 3B defects. Pelvic discontinuity was noted in one case. Augments were used in 21 hips to support the shell and an acetabular component-cage construct was implanted in one case. At a mean follow-up of 41 months (24 to 62), 22 components remained well fixed. Two patients required rerevision of the liners for prosthetic joint instability. Clinically, the mean Harris Hip Score improved from 43.0 pre-operatively (14 to 86) to 75.7 post-operatively (53 to 100). The mean pre-operative Merle d’Aubigné score was 8.2 (3 to 15) and improved to a mean of 13.7 (11 to 18) post-operatively.

These short-term results suggest that modular porous metal components are a viable option in the reconstruction of Paprosky type 3 acetabular defects. More data are needed to determine whether the system yields greater long-term success than more traditional methods, such as reconstruction cages and structural allografts.

Ultra-high-molecular-weight polyethylene sterilised in the absence of air and highly cross-linked polyethylene have been used to avoid osteolysis and loosening in total hip replacement. Our prospective randomised study has assessed the results using two different polyethylenes associated with the same prosthetic design. We assessed 45 Allofit acetabular components with a Sulene-polyethylene liner of conventional polyethylene gamma sterilised with nitrogen and 45 Allofit acetabular components with a Durasul-polyethylene liner sterilised in ethylene oxide, both matched with an Alloclassic stem with a 28 mm modular femoral head. The prostheses were implanted between May 1999 and December 2001. The mean follow-up was for 66.3 months (60 to 92). The linear penetration of the femoral head was estimated at 6 weeks, at 6 and 12 months and annually thereafter from standardised digitised radiographs using image-analysis software.

There was no loosening of any prosthetic component. There were no radiolucent lines or osteolysis. The mean rate of penetration calculated from regression analysis during the first five years was 38 μm/year (sd 2) for the Sulene group and 6 μm/year (sd 1) for the Durasul group (p = 0.00002). The rate of penetration of the Durasul group was 15.7% of that of the Sulene group.

Between January 1998 and December 1998, 82 consecutive patients (86 hips) underwent total hip arthroplasty using a trabecular metal monoblock acetabular component. All patients had a clinical and radiological follow-up evaluation at six, 12 and 24 weeks, 12 months, and then annually thereafter. On the initial post-operative radiograph 25 hips had a gap between the outer surface of the component and the acetabular host bed which ranged from 1 to 5 mm. All patients were followed up clinically and radiologically for a mean of 7.3 years (7 to 7.5). The 25 hips with the 1 to 5 mm gaps were studied for component migration at two years using the Einzel-Bild-Roentgen-Analyse (EBRA) digital measurement method. At 24 weeks all the post-operative gaps were filled with bone and no acetabular component had migrated. The radiographic outcome of all 86 components showed no radiolucent lines and no evidence of lysis. No acetabular implant was revised. There were no dislocations or other complications. The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal.