Mid-term Results of Revision Total Hip Arthroplasty Using Modular Cementless Femoral Stems

Implant breakage and revision factors for modular fluted tapered stems in revision total hip arthroplasty

PURPOSE

Modular stems in revision total hip arthroplasties allow diaphyseal fixation and optimal restoration of the architecture of the proximal femur. Several studies report metaphyseal implant breakage having a negative impact on survivorship. The aim of the study was to evaluate the outcome of an uncemented modular fluted tapered stem (MFT) in revision surgery.

METHODS

In a retrospective study, 316 patients who had revision surgery using the same design of MFT implant (Modular Revision Stem [MRS], Lima Corporate, Italy) between 2012 and 2017 were identified. Patients were male in 51% of cases and mean age was 74 years. Indications were 110 periprosthetic fractures, 98 periprosthetic joint infection, 97 aseptic loosening, 10 instability and 1 other cause. Survivorship, complications, clinical and radiographic outcomes, were assessed. Mean follow-up was 5 years.

RESULTS

There was no implant breakage. At 5-year follow-up, the survivorship, free from revision for aseptic loosening and free of revision for any reason were 96% and 87%, respectively. At last follow-up (8 years), these figures were 92% and 71%, respectively. 31 implants were revised. The risk of revision for any cause was higher for extreme length metaphyseal implants, hazard ratio was 3.7 (95% CI, 1.82-7.52). A mean stem subsidence of 9 mm was noted in 37 cases; 4 were revised for aseptic loosening. The Harris Hip Score at final follow-up was 82.

CONCLUSIONS

At 5-year follow-up, the MFT implant showed a good survivorship and outcomes with no specific complications. Unlike literature reports, no specific complications occurred with this design. Stem junction positioning and therefore metaphyseal length may be key to optimise long-term survivorship. However, a longer follow-up is needed as implant breakage is more often seen after long implantation times.

The Early- to Mid-term Outcome of Novel Cementless Modular Femoral Stem in East Asian Patients

Background

Early firm fixation of the femoral implant is crucial in total hip arthroplasty (THA) with unstable metaphysis or a large degree of femoral bone loss. This study aimed to evaluate the outcomes of THA using a novel cementless modular, fluted, tapered stem in such cases.

Methods

From 2015 to 2020, 105 hips (101 patients) had surgery performed by two surgeons at two tertiary hospitals using a cementless modular, fluted, tapered stem for periprosthetic fractures, massive bone loss, prosthetic joint infection sequelae, or tumorous condition. Clinical outcomes, radiographic results, and survivorship of the implant were evaluated.

Results

The average follow-up period was 2.8 years (range, 1-6.2 years). The Koval grade was 2.7 ± 1.7 preoperatively and maintained at 1.2 ± 0.8 at the latest follow-up. The plain radiograph showed bone ingrowth fixation in 89 hips (84.8%). The average stem subsidence at postoperative 1 year was 1.6 ± 3.2 mm (range, 0-11.0 mm). Five reoperations (4.8%) were needed, including 1 for acute periprosthetic fracture, 1 for recurrent dislocation, and 3 for chronic periprosthetic joint infection. Kaplan-Meier survivorship with reoperation for any reason as the endpoint was 94.1%.

Conclusions

The early- to mid-term results of THA with the novel cementless modular, fluted, tapered THA stem system were satisfactory clinically and radiologically. The shortcomings inherent to its modularity were not identified. This modular femoral system may provide adequate fixation and be a practical option in the setting of complicated THA.

Clinical, functional and radiographic outcomes after revision total hip arthroplasty with tapered fluted modular or non-modular stems: a systematic review

PURPOSE

The aim of the study was to systematically evaluate clinical outcomes of tapered fluted stems, either monoblock or modular, in revision total hip arthroplasty.

METHODS

PubMed, EMBASE and Web of Science and Cochrane databases were systematically searched by 2 researchers. Clinical studies reporting primarily on survival and re-revision rates, and secondarily on subsidence, dislocation, intraoperative fractures, periprosthetic fractures and infection were included. 2 investigators assessed the quality of the studies.

RESULTS

46 studies were included in this review, reporting on 4601 stem revisions. The pooled re-revision rate was 5.1% and long-term survival ranged from 75% to 98.5%. No differences were observed between monoblock and modular stems regarding re-revision rate, dislocation rate, periprosthetic fracture rate or infection rates. Monoblock stems exhibited more subsidence and modular stems displayed more intraoperative fractures.

CONCLUSIONS

Satisfactory results can be obtained with the use of tapered fluted end-bearing stems. Monoblock stems offer the same clinical results as modular stems.

Mid- to Long-Term Outcomes of Cementless Modular, Fluted, Tapered Stem for Massive Femoral Bone Loss in Revision Total Hip Arthroplasty

OBJECTIVE

To evaluate mid- to long-term results of revision total hip arthroplasty for massive femoral bone loss using a cementless modular, fluted, tapered stem.

METHODS

This is a retrospective study performed at a single hospital. During the period of January 2007 to January 2015, 33 patients (34 hips) underwent primary revision surgery with cementless modular, fluted, tapered stems due to femoral bone loss. Sixteen men and 17 women were included in the study, with an average age of 63.9 ± 11.7 years (range, 27 to 88 years). Operative data including operative duration, length of incision, drainage volume and duration, blood loss and transfusion, cases of bone graft and extended trochanteric osteotomy were recorded. Clinical evaluation was performed using Harris hip score (HHS), visual analogue scale (VAS), and patients' satisfaction. Radiographic data including femoral stem fixation, subsidence, integrin of allograft bone, and leg length discrepancy were assessed. Complications and survivorship were evaluated using Kaplan-Meier survival rate.

RESULTS

The mean follow-up was 9.1 ± 2.5 years (range, 5-13 years). The Harris hip score was 43.6 ± 11.5 preoperatively and maintained at 86.5 ± 6.6 at the time of latest follow-up (P < 0. 05). The X-ray showed bone ingrowth fixation in 30 hips (88%), fibrous stable fixation in three hips (9%), and instability in one hip (3%). The average stem subsidence was 3.9 ± 2.2 mm (range, 1 to 10 mm). The mean difference in leg length in our study was 3.3 ± 2.7 mm (range, 0 to 10 mm), and the leg length discrepancy in 28 (82%) patients was within 5 mm. No case of junction fracture was observed. Seven (21%) intraoperative fractures occurred in our study. Three (9%) cases with infection were observed after revision. Six (18%) patients had lower limb vein thrombosis. The survivorship of prostheses with re-revision for any reason was 95% (95% CI, 12.0 to 13.0) at the 10-year follow-up. Three (9%) re-revisions were needed, including one for aseptic loosening, one for dislocation, and one for infection.

CONCLUSION

The mid- to long-term results of revision total hip arthroplasty with the cementless modular, fluted, tapered stems are encouraging for massive femoral bone loss.

Distal fixation stems for revision of total hip replacement

The purpose of this study was to retrospectively assess patients treated with modular, non-cemented, tapered, fluted, distal fixation stems. We included patients with 24 months mínimum follow-up. Diagnosis that led to revisions were described. The radiographic analysis was made with preoperative, immediate postoperative and last control postoperative X-rays. Sixty-seven patients met inclusion criteria. We observed 59,7% (n=40) Osteointegration, 34,3% of Stable Fibrosis and 5,97% Unstable fibrosis. Stress Shielding was registered with 10,44% and Subsidence was observed in 34,3% of the patients. Modular, fluted, tapered, distal fixation stems have an excellent survival rates.

Femoral stem modularity

Femoral stem modularity in hip replacement was first developed to connect a ceramic head to the stem, then extended to metal heads using the Morse taper principle. Is it a good thing, or a necessary evil? It contributes to improving lower limb length and lateralization setting, at the cost of fairly rare complications such as dissociation and fretting corrosion, which can exceptionally lead to ARMD (Adverse Reaction to Metal Debris). Modular necks were later recommended, with a double Morse taper: cylindrical for the head junction, and more or less flattened for the stem. Is this one modularity too far? Dual modularity in theory perfectly reproduces the biomechanical parameters of the hip, but is unfortunately associated with fractures and severe corrosion, leading to ARMD and pseudotumor, especially in Cr-Co necks. Moreover, it provides no functional advantage, and no longer has a role outside dysplasia and other femoral deformities. Metaphyseal-diaphyseal modularity is not widespread in primary implants, and is it really necessary? Only one model has been widely studied: S-Rom™ (Depuy®). It features a metaphyseal sleeve adapting to the anatomy of the proximal femur, with a stem fitted via an inverse Morse taper. Its only interest is in case of congenital dislocation; like all metal connections, it incurs a risk of fracture and corrosion. On the other hand, modularity is widely employed in revision implants. Does it really help these procedures? The connection between a proximal femoral component of variable geometry and a diaphyseal stem with press-fit distal fixation provides a real solution to problems of length, lateralization and anteversion. Early models encountered high rates of fracture, but current implants and rigorous surgical technique have reduced this risk. Corrosion is a less serious problem, as the Morse taper undergoes only axial stress, without the friction undergone by other models subject to varus stress.

Clinical and radiographic outcomes of total hip replacement with a 3-part metaphyseal osseointegrated titanium alloy stem enhanced with low plasticity burnishing: a mean 5-year follow-up study

Background

This study evaluates midterm results of a 3-part titanium alloy stem with metaphyseal fixation and a neck-metaphyseal taper junction strengthened with low plasticity burnishing (LPB). Our hypothesis is that this multimodular implant with LPB succeeds in offering the advantages of three-part modularity without junctional failure.

Methods

Twenty-eight of 32 complex primary (n = 9) and revision (n = 9) total hip arthroplasties were accounted for with minimum 2-year follow-up. Clinical and radiographic data were reviewed at a mean follow-up period of 60 months. One stem, removed for failure to osseointegrate, was submitted for sectioning and taper examination.

Results

There were no modular junction failures despite body mass indices of 20 to 40 and offsets of 34 to 47 mms. Implant survival was 96.3%, with one removal due to aseptic loosening in a patient with chronic renal failure. Taper analyses of the removed implant showed minimal damage. Preoperative and postoperative Harris Hip Scores and Oxford Hip Scores were 20 to 86 and 16 to 41, respectively. Patient satisfaction was 9.7/10. Radiographs showed stem subsidence >2 mm and radiolucencies around the metaphyseal cone only in the hip requiring implant removal.

Conclusions

This 3-part titanium alloy modular stem with LPB of the neck-metaphyseal taper junction showed good functional and radiographic results at a mean 5 years without junctional failures. Although this follow-up exceeds previously published reports, longer follow-up will be important to confirm our confidence in the additional strengthening provided by LPB.

A systematic review of the causes of failure of Revision Total Hip Arthroplasty

This study reviewed literature published in the last 10 years to investigate the reasons for revision failure. A total of 9952 revisions were identified and it was determined that the number one cause of failure was aseptic loosening (23.19%), followed by instability (22.43%) and infection (22.13%). Further analysis of applicable revisions investigated BMI and age at the failure rates. The rate of rerevision in obese patients was markedly higher (p < 0.01) compared to non-obese patients and individuals receiving a revision THA under the age of 55 are at a higher risk of rerevision (p < 0.01).

Mid-term outcomes of titanium modular neck femoral stems in revision total hip arthroplasty

Background

Modular stems have been widely studied as they allow intraoperative adjustments (offset, anteversion, limb length) to better restore hip biomechanics. Many authors reported outcomes of revision total hip arthroplasty (THA) using modular stems with metaphyseal-diaphyseal junctions, however, little is known about modular neck femoral stems (MNFS) with metaphyseal-epiphyseal junctions. We therefore aimed to report outcomes and implant survival of a MNFS in a consecutive series of revision THA at a minimum follow-up of 5 years.

Methods

We reviewed a consecutive series of 28 revision THAs performed between February 2010 and March 2012 using an uncemented MNFS. The final study cohort included 25 patients living with their original components, at a mean follow-up of 68.4±7.4 months and aged 67.7±11.6 years at index operation.

Results

The Harris Hip Score (HHS) improved from 39.1±19.2 pre-operatively to 78.1±18.3 post-operatively, and the Postel Merle d'Aubigné score (PMA) improved from 9.8±3.0 pre-operatively to 14.8±2.8 post-operatively. The postoperative limb length discrepancy (LLD) was >10 mm in 18% of the hips. There were no significant differences of femoral offset and neck shaft angle (NSA) between operated and contralateral hips. Two hips (8.0%) showed new periprosthetic radiolucent lines. Periprosthetic fractures (PPF) occurred in 3 hips (12%). No subluxations, dislocations or implant breakages were reported. One revision (3.6%) was performed with retrieval of the revision stem for infection. The Kaplan-Meier (KM) survival at 5 years, using stem revision as endpoint, was 96.0%.

Conclusions

The Optimal^® MNFS provided a satisfactory survival and clinical outcomes at 5 years, with no noticeable adverse effects resulting from the additional modular junction.

Long-term results of acetabular reconstruction using irradiated allograft bone

AIMS

The management of acetabular defects at the time of revision hip arthroplasty surgery is a challenge. This study presents the results of a long-term follow-up study of the use of irradiated allograft bone in acetabular reconstruction.

PATIENTS AND METHODS

Between 1990 and 2000, 123 hips in 110 patients underwent acetabular reconstruction for aseptic loosening, using impaction bone grafting with frozen, irradiated, and morsellized femoral heads and a cemented acetabular component. A total of 55 men and 55 women with a mean age of 64.3 years (26 to 97) at the time of revision surgery are included in this study.

RESULTS

At a mean follow-up of 16.9 years, there had been 23 revisions (18.7%), including ten for infection, eight for aseptic loosening, and three for dislocation. Of the 66 surviving hips (58 patients) that could be reassessed, 50 hips (42 patients; 75.6%) were still functioning satisfactorily. Union of the graft had occurred in all hips with a surviving implant. Survival analysis for all indications was 80.6% at 15 years (55 patients at risk, 95% confidence interval (CI) 71.1 to 87.2) and 73.7% at 20 years (eight patients at risk, 95% CI 61.6 to 82.5).

CONCLUSION

Acetabular reconstruction using frozen, irradiated, and morsellized allograft bone and a cemented acetabular component is an effective method of treatment. It gives satisfactory long-term results and is comparable to other types of reconstruction. Cite this article: Bone Joint J 2018;100-B:1449-54.

Double-tapered conical taper in primary and revision surgery: rationale and short-term follow-up

BACKGROUND:

The new double-conical tapered stem is a novel cementless modular system, which is indicated for both primary and revision surgeries. It has been designed with different angles at the proximal (5°) and distal sections (1° 36') in order to obtain optimal fixation by proximal and distal fit and fill of the femoral canal.

AIM:

The aim of this prospective study was to evaluate the short-term clinical and radiographic outcomes of primary and revision hip surgery with the new double-conical stem.

METHODS:

61 stems were implanted (December 2013 to September 2016) in 42 cases of primary and in 19 cases of revision surgery. The mean age of patients was 64.7 (17-94; standard deviation [SD] 21.9) years.

RESULTS:

The mean body mass index of the patients was 24.6 (17-34.6). In 3 cases of developmental dysplasia of the hip we performed femoral shortening osteotomy. The mean follow-up was 26 (8-40) months. 3 patients died due to causes unrelated to surgery. Postoperative complications included 3 hip dislocations, 2 infections and 1 case of stem explant for metastatic tumour. For all other cases, at the last follow-up radiographs showed no loosening, no radiolucent lines nor subsidence. The mean Harris Hip Score significantly improved from 45 (range 35-58) preoperatively to 87 (range 75-94). Leg length discrepancy was found in 10% of cases but never >1 cm.

CONCLUSIONS:

Radiographic analysis showed the bone-stem contact full at 2 levels of taper. The double-tapered prosthetic stem can therefore be usefully employed both in primary and in revision surgeries.

Mid-term results of revision total hip arthroplasty with an uncemented modular femoral component

INTRODUCTION

During revision total hip arthroplasty (THA), the surgeon commonly faces deficient proximal femoral bone. In this situation, distal fixation of the prosthesis is required. The aim of the current retrospective study is to assess the clinical and radiographic mid-term outcome of revision total hip arthroplasty using a modular uncemented, tapered, grit-blasted, distal straight stem system.

METHODS

This retrospective study included 70 femoral revisions that were performed in 67 patients using the device of interest. All patients were operated on via an extended trochanteric osteotomy. 60 revisions were performed as 1-stage (12 infected) and 10 as 2-stage (all infected) revisions. At 3 months postoperatively and at final follow-up, patients were assessed radiographically for the presence of osteolysis and for distal integration.

RESULTS

The mean follow-up time was 4.3 (2.0-7.6) years. 4 patients had a removal of at least 1 prosthetic component. Stem survival for any reason was 92% after 5 years (95% confidence interval [CI], 83%-100%). With aseptic loosening of the stem as the endpoint of interest, survival after 5 years was 96% (95% CI, 88%-100%). A postoperative subsidence rate of 14.7% was found. No perioperative femoral fractures were found in the current patient series.

CONCLUSIONS

This study showed excellent mid-term survival and good clinical and radiographic outcomes in patients who had undergone revision THA with a modular uncemented, tapered, straight design.