Clinical and radiological outcomes of acetabular revision with the Delta Revision TT cup

Early hip fracture surgery and rehabilitation. How to improve functional quality outcomes. A retrospective study

INTRODUCTION

Hip fractures are one of the major disability causes associated with a high morbidity and mortality rate. Early surgery and stable fixation could be associated with better pain control, possibly lower mortality rates, and early recovery of autonomy.

Forged to heal: The role of metallic cellular solids in bone tissue engineering

Metallic cellular solids, made of biocompatible alloys like titanium, stainless steel, or cobalt-chromium, have gained attention for their mechanical strength, reliability, and biocompatibility. These three-dimensional structures provide support and aid tissue regeneration in orthopedic implants, cardiovascular stents, and other tissue engineering cellular solids. The design and material chemistry of metallic cellular solids play crucial roles in their performance: factors such as porosity, pore size, and surface roughness influence nutrient transport, cell attachment, and mechanical stability, while their microstructure imparts strength, durability and flexibility. Various techniques, including additive manufacturing and conventional fabrication methods, are utilized for producing metallic biomedical cellular solids, each offering distinct advantages and drawbacks that must be considered for optimal design and manufacturing. The combination of mechanical properties and biocompatibility makes metallic cellular solids superior to their ceramic and polymeric counterparts in most load bearing applications, in particular under cyclic fatigue conditions, and more in general in application that require long term reliability. Although challenges remain, such as reducing the production times and the associated costs or increasing the array of available materials, metallic cellular solids showed excellent long-term reliability, with high survival rates even in long term follow-ups.

A prospective radiostereometric analysis of the stability of a metal-backed glenoid component/autograft composite in reverse shoulder arthroplasty

Aims

Reverse total shoulder arthroplasty (rTSA) can be used in complex cases when the glenoid requires reconstruction. In this study, a baseplate with composite bone autograft and a central trabecular titanium peg was implanted, and its migration was assessed for two years postoperatively using radiostereometric analysis (RSA).

Methods

A total of 14 patients who underwent a rTSA with an autograft consented to participate. Of these, 11 had a primary rTSA using humeral head autograft and three had a revision rTSA with autograft harvested from the iliac crest. The mean age of the patients was 66 years (39 to 81). Tantalum beads were implanted in the scapula around the glenoid. RSA imaging (stereographic radiographs) was undertaken immediately postoperatively and at three, six, 12, and 24 months. Analysis was completed using model-based RSA software. Outcomes were collected preoperatively and at two years postoperatively, including the Oxford Shoulder Score, the American Shoulder and Elbow Score, and a visual analogue score for pain. A Constant score was also obtained for the assessment of strength and range of motion.

Results

RSA analysis showed a small increase in all translation and rotational values up to six months postoperatively, consistent with settling of the implant. The mean values plateaued by 12 months, with no evidence of further migration. In four patients, there was significant variation outside the mean, which corresponded to postoperative complications. There was a significant improvement in the clinical and patient-reported outcomes from the preoperative values to those at two years postoperatively (p < 0.001).

Conclusion

These findings show, using RSA, that a glenoid baseplate composite of a trabecular titanium peg with autograft stabilizes within the glenoid about 12 months after surgery, and reinforce findings from a previous study of this implant/graft with CT scans at two years postoperatively, indicating that this type of structural composite results in sound early fixation.

Survivorship of Allologous Structural Bone Graft at a Minimum of 2 Years When Used to Address Significant Glenoid Bone Loss in Revision Shoulder Arthroplasty: A Computed Tomographic and Clinical Review

Background

This study assesses outcomes in revision shoulder replacements where the glenoid bone loss was managed using a structural allograft (donated femoral head) in combination with a trabecular titanium (TT) implant.

Methods

We contacted patients who had undergone revision shoulder arthroplasty using the Lima Axioma TT metal-backed glenoid with an allologous bone graft as a composite who were over 2 years since surgery. Patients underwent computerd tomography evaluation, clinical review, and scoring preoperatively, at 6 months and the latest follow-up.

Results

Fifteen patients were included with a mean age of 59 (33-76). The average follow-up period was 40.5 months (24-51). 80% showed satisfactory bone graft incorporation and peg integration at the latest follow-up. Three had signs of significant bone graft resorption, although in 2 patients the pegs were still soundly fixed in the host bone. Clinically all patients showed a statistically significant improvement in pain relief, movement, and function. No unusual complications were reported.

Conclusion

Results show femoral head structural allograft in combination with TT metal-backed glenoid baseplate is a viable option for revision total shoulder replacement in the context of massive glenoid bone loss. We do, however, acknowledge that this resorption rate is higher than in other reported series where autograft is used.

Trabecular titanium cups in acetabular revision arthroplasty: analysis of 10-year survivorship, restoration of center of rotation and osteointegration

AIMS

In case of severe bone loss, acetabular revision can be challenged using extra porous pure trabecular titanium (TT) revision cups designed to ensure enhanced iliac and ischiatic purchase. Aim of the study is to report on the clinical and radiological results of a TT acetabular component, evaluating functional outcome, restoration of the hip center of rotation and osteointegration.

METHODS

85 patients, who underwent acetabular revision with a TT revision cup system between October 2009 and December 2018, were included in a retrospective study. Clinical outcome were assessed with Harris Hip Score (HHS). The hip rotation center was measured using the Pierchon method on the AP pelvis film. Loosening of the cup was determined according to the Kosashvili modification of Gill's criteria. Kaplan- Meier survivorship curve was performed. Results The mean follow-up was 6.12 years. The average HHS improved from 54.7 points to 89.7 points (p < 0.05). Two acetabular components (2.3%) were re-revised after a mean of 5.6 years, for aseptic loosening and for infection, with a progressive radiolucency and a > 5 mm vertical migration, respectively. The radiographic evaluation of the position of the hip rotation center revealed a statistically significant difference (p < 0.05) between the pre- and post-operative values. The hip rotation center was correctly restored within 5% of the reference Pierchon values in a percentage of 85.4% relative to horizontal parameters and within 8% in a percentage of 66.7% relative to vertical parameters. 5-year and 10-year survivorships were, respectively, 100% and 88%.

CONCLUSIONS

In case of severe bone loss, TT revision cup system allows for good restoration of center of rotation and osteointegration showing good 10-year survival rate.

Primary or revision arthroplasty with an integrated acetabular cup-MUTARS® RS cup system

INTRODUCTION

The aim of this article is to show a new concept of indication and application of the MUTARS^® RS Cup System in primary and revision hip arthroplasty. This integrated system is applicable for different acetabular cup replacements in patients with acetabular fractures or instable defects, as well as periprosthetic acetabular fractures. The MUTARS^® RS Cup System is a cementless revision cup for insertion into the acetabulum with an integrated polyethylene cup, which fits to a regular or bipolar head. This system replaces the conventional approach for acetabular revision with a Burch-Schneider ring, in which a normal polyethylene cup is cemented. This interface with its complications is avoided with this system of a titanium revision cup with integrated polyethylene cup. Steps of preoperative planning and the intraoperative implementation will be highlighted in this article.

MATERIAL AND METHODS

This system was applied in 49 patients with 52 MUTARS^® RS Cup Implantations in 30 males, 22 females, with an average age of 76,1 years (36,9-94,4 years).

RESULTS AND DISCUSSION

The system shows a good operative feasibility, as well as a reliable handling and safe method for stable treatment of non-reconstructable acetabular fractures or acetabular incongruencies and instabilities.

Survivorship of autologous structural bone graft at a minimum of 2 years when used to address significant glenoid bone loss in primary and revision shoulder arthroplasty: a computed tomographic and clinical review

BACKGROUND

Severe glenoid bone loss remains a challenge in patients requiring shoulder arthroplasty and often requires autogenous bone grafting. The purpose of this study was to assess the integrity of the bone graft at 2 years in a series of primary and revision shoulder replacements where glenoid bone loss was managed using a structural autograft (humeral head or iliac crest bone graft) in combination with a trabecular titanium (TT) implant.

METHODS

Ethical approval was sought, and the study has a portfolio study status by the NIHR (17/YH/0318). We contacted patients who had primary and revision shoulder arthroplasty with Lima Axioma TT metal-back glenoid with autologous bone graft and were more than 2 years since their operation. All eligible patients underwent computed tomographic evaluation, clinical review, and scoring. Early failures of composite fixation and patients who had revision procedures were excluded (2 patients).

RESULTS

Forty-one patients (43 shoulders) with a mean age of 65 years (range 33-85 years) were reviewed. There were 24 women and 17 men. The average follow-up period was 40 months (range 24-59 months). Primary arthroplasty was performed in 24 shoulders, whereas 19 shoulders had revision arthroplasty. Twenty-five shoulders had reverse shoulder replacement and 18 had anatomic shoulder replacement. Twenty-four shoulders had graft taken from the humeral head, and 19 had iliac crest bone graft, reflecting the number of revisions. We used Wrightington classification for porous metal implant and bone graft incorporation. Satisfactory bone graft incorporation (>50%) was seen in 40 shoulders, and only 3 patients had <50% graft incorporation. The scans at 2 years or later showed no significant deterioration in the bone graft from the early postoperative scans. Average forward elevation improved from 50° (preoperative) to 98° (range 35°-150°). The mean improvement in mean Oxford Shoulder Score was 16 (preoperative, 15; postoperative, 31) and the mean improvement in Constant score improvement was 36 (preoperative, 12; postoperative, 48). The mean postoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score was 64 (range 30-85).

CONCLUSION

The use of TT in conjunction with autologous bone graft provides a reliable method of addressing glenoid bone defects in primary and revision shoulder arthroplasty. This graft-trabecular metal composite has been shown to integrate well and remain largely unchanged over a 2-year period. A stable baseplate is essential in difficult primary and revision arthroplasty situations. The stability of this construct in our series is reflected in the satisfactory outcomes.

Highly Porous Titanium Acetabular Components in Primary and Revision Total Hip Arthroplasty: A Systematic Review

BACKGROUND

A number of papers have been published reporting on the clinical performance of highly porous coated titanium acetabular cups in primary and revision total hip arthroplasty (THA). However, no systematic review of the literature has been published to date.

METHODS

The US National Library of Medicine (PubMed/MEDLINE), Embase, and the Cochrane Database of Systematic Reviews were queried for publications utilizing the following keywords: "tritanium" OR "highly-porous" AND "titanium" OR "acetabular" AND "trabecular" AND "titanium".

RESULTS

Overall, 16 studies were included in this review (11,366 cases; 60% females, 2-7 years mean follow-up). The overall survival rate of highly porous titanium acetabular components in primary cases was 99.3% (10,811 of 10,886 cases), whereas the rate of aseptic loosening was 0.1%. The overall survival rate of the highly porous titanium acetabular components in revision THA cases was 93.5% (449 of 480 cases), whereas the rate of aseptic loosening was 2.1%.

CONCLUSION

There was moderate quality evidence to show that the use of highly porous titanium acetabular components in primary and revision THA cases is associated with satisfactory clinical outcomes in the short- and medium-term, without showing any evidence of cup migration or radiolucency. Taking into consideration that there is no evidence yet regarding the long-term survivorship of these components, we feel that further research of higher quality is required to generate more evidence-based conclusions regarding the longevity of highly porous titanium acetabular implants compared with conventional titanium counterparts.

Characterization of dimensional, morphological and morphometric features of retrieved 3D-printed acetabular cups for hip arthroplasty

Background

Three-dimensional (3D) printing of porous titanium implants is increasing in orthopaedics, promising enhanced bony fixation whilst maintaining design similarities with conventionally manufactured components. Our study is one of the first to non-destructively characterize 3D-printed implants, using conventionally manufactured components as a reference.

Methods

We analysed 16 acetabular cups retrieved from patients, divided into two groups: ‘3D-printed’ (n = 6) and ‘conventional’ (n = 10). Coordinate-measuring machine (CMM), electron microscopy (SEM) and microcomputed tomography (micro-CT) were used to investigate the roundness of the internal cup surface, the morphology of the backside surface and the morphometric features of the porous structures of the cups, respectively. The amount of bony attachment was also evaluated.

Results

CMM analysis showed a median roundness of 19.45 and 14.52 μm for 3D-printed and conventional cups, respectively (p = 0.1114). SEM images revealed partially molten particles on the struts of 3D-printed implants; these are a by-product of the manufacturing technique, unlike the beads shown by conventional cups. As expected, porosity, pore size, strut thickness and thickness of the porous structure were significantly higher for 3D-printed components (p = 0.0002), with median values of 72.3%, 915 μm, 498 μm and 1.287 mm (p = 0.0002). The median values of bony attachment were 84.9% and 69.3% for 3D-printed and conventional cups, respectively (p = 0.2635).

Conclusion

3D-printed implants are designed to be significantly more porous than some conventional components, as shown in this study, whilst still exhibiting the same shape and size. We found differences in the surface morphologies of the groups, related to the different manufacturing methods; a key finding was the presence of partially molten particles on the 3D-printed cups.