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

Survival analysis of 3D printed acetabular implants in revision total hip arthroplasty associated with severe pelvic discontinuities

BACKGROUND

Surgeons still face difficulties when performing aseptic acetabular revision on patients with extensive defects. Advances in three-dimensional printing technology (3DP) have afforded to the surgeons to create a patient-specific implant matching the morphology and topography of the defect.

OBJECTIVE

The aim of the current research was to determine the survivorship in the treatment of acetabular bone defects with pelvic discontinuity (PD).

METHODS

In order to reconstruct Paprosky type III defects with PD, twenty-three patients underwent revision total hip arthroplasty (THA) utilizing 3D-printed implants (Mobelife). The primary outcomes were the implant-associated failure rate correlated with survivorship. As secondary variables, complications and the effect of age, sex, comorbidities, history of infections and the presence of other lower limb arthroplasties on a new revision were analyzed.

RESULTS

Patients were followed out to a mean of 67.22 ± 39.44 months (range, 0.9-127 months). Mobelife implant mean survival was 102.57 ± 9.90 months (95% CI 83.17-121.96). The cohort's implant one-year survival rate was 87%; at ten years, it dropped to 78.3%. There were four revisions: three due to periprosthetic joint infection (PJI) and one case due to aseptic loosening. Cox regression analysis did not identify any variable as predictor of failure.

CONCLUSION

The use of 3DP patient-specific acetabular components has shown encouraging results and it is a viable treatment option for addressing acetabular defects with combined PD in aseptic THA revision.

A novel and secure technique of stemmed acetabular cup implantation in complex hip reconstructions: a comparative study and technical note

PURPOSE

The stemmed acetabular cup (SAC) can be considered in several complicated situations. This type of prosthesis uses the iliac isthmus, which is most often preserved, thus allowing solid anchorage. Its implantation is prone to mechanical complications intraoperatively, such as extra-isthmic effraction, fracture, and early aseptic loosening. The aim of our study was to compare a new technique using a flexible motorized reamer combined with isthmus catheterization (Group A) versus the standard technique deploying a rigid reamer alone (Group B).

MATERIALS AND METHODS

A retrospective analysis was carried out of the SACs implanted at our hospital. The main evaluation criterion was visualization of extra-isthmic effraction (EIE) of the stem.

RESULTS

Fifty-six SACs (Integra Lepine®, Genay, France) were implanted, 31 in group A and 25 in group B. The mean follow-up was 21.6 months ± 22.3. This study found fewer EIEs using a flexible motorized reamer (0 versus 5, p = 0.014), less perioperative bleeding (p = 0.054), and less aseptic loosening in group A (p = 0.034). There was no difference in terms of infection or other mechanical complications post-operatively between the two groups.

CONCLUSION

Using iliac catheterization combined with a flexible motorized reamer when implanting a SAC helps to avoid EIE and it also appears to reduce complications such as peri-operative bleeding and early aseptic loosening. We recommend use of this surgical technique rather than a rigid reamer alone, and this new technique should allow widespread and more accessible use of this specific type of implant.

Primary Stability in Hip Revision Arthroplasty: Comparison of the Stability of Cementless Fixed Augments on a Modular Acetabular Cage System with and without Cranial Straps

The goal of this study is to evaluate the primary stability of a cementless augment-and-modular-cage system with and without the addition of cranial straps in a standardized in vitro setting. As the surrogate parameter for the evaluation of primary stability, the measurement of relative motion between the implant components themselves and the bone will be used. Acetabular revision components with a trabecular titanium augment in combination with a large fourth-generation composite left hemipelvis were assembled. These constructs were divided into two groups with (S) and without cranial straps (nS). A total of 1000 cycles was applied at each of three load levels. Relative movements (RM) between the components were measured. Load levels display a significant effect on the amount of RM at all interfaces except between shell/augment. The group assignment appears to have an effect on RM due to significantly differing means at all interfaces. Between bone/shell RM increased as load increased. NS displayed significantly more RM than S. Between shell/augment RM remained constant as load increased. Between shell/cup S showed more RM than nS while both groups' RM increased with load. We conclude a significant increase of primary stability between the shell and the bone through the addition of cranial straps. Relative motion between components (shell/cup) increases through the addition of cranial straps. A clinical impact of this finding is uncertain and requires further investigation. Finally, the cementless fixation of the augment against the rim-portion of the shell appears stable and compares favorably to prior investigation of different fixation techniques.

Pelvic discontinuity: a challenge to overcome

Pelvic discontinuity (PD) has been a considerable challenge for the hip revision arthroplasty surgeon. However, not all PDs are the same. Some occur during primary cup insertion, resembling a fresh periprosthetic fracture that separates the superior and inferior portions of the pelvis, while others are chronic as a result of gradual acetabular bone loss due to osteolysis and/or acetabular implant loosening.In the past, ORIF, various types of cages, bone grafts and bone cement were utilized with little success. Today, the biomechanics and biology of PD as well as new diagnostic tools and especially a variety of new implants and techniques are available to hip revision surgeons. Ultraporous cups and augments, cup-cage constructs and custom triflange components have revolutionized the treatment of PD when used in various combinations with ORIF and bone grafts. For chronic PD the cup-cage construct is the most popular method of reconstruction with good medium-term results.Dislocation continues to be the leading cause of failure in all situations, followed by infection. Ultimately, surgeons today have a big enough armamentarium to select the best treatment approach. Case individualization, personal experience and improvisation are the best assets to drive treatment decisions and strategies. Cite this article: EFORT Open Rev 2021;6:459-471. DOI: 10.1302/2058-5241.6.210022.

Survivorship and Clinical Outcomes of Custom Triflange Acetabular Components in Revision Total Hip Arthroplasty: A Systematic Review

BACKGROUND

Several studies have evaluated the survivorship and clinical outcomes of custom triflange acetabular component (CTAC) usage in complex acetabular revision; however, there remains no consensus on the overall performance of this custom implant design. We therefore performed a systematic review of the literature in order to examine survivorship and complication rate of CTAC usage.

METHODS

A systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A comprehensive search of PubMed, MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews was conducted for English articles using various combinations of the keywords "custom triflange," "custom-made triflange," "acetabular triflange," "THA," "THR," "revision," "bone loss," "bone defect," and "pelvic discontinuity."

RESULTS

In all, 17 articles met our inclusion criteria. A total of 579 CTACs were implanted. The all-cause revision-free survivorship was 82.7%. The overall complication rate was 29%. Dislocation and infection were the most common complications observed with an incidence of 11% and 6.2%, respectively. Nerve injuries following CTAC placement had an incidence of 3.8%. The incidence of CTAC aseptic loosening was 1.7%. Overall, patients had improved outcomes as documented by postoperative hip scores.

CONCLUSION

Based on the current data, CTACs have a high complication rate but remain an efficacious treatment option in complex acetabular reconstructions. When dealing with patients with significant acetabular bone loss for revision total hip arthroplasty, surgeons should continue to consider CTACs as a viable option but educate patients as to the increased risk of postoperative complications and reoperations.

Preliminary results of a 3D-printed acetabular component in the management of extensive defects

INTRODUCTION

The treatment of extensive bone loss and massive acetabular defects can be compounded by several challenges and pitfalls. The survivorship following acetabular revision with extensive bone loss is still unsatisfactory. The goal of the present study was to analyse the outcomes of 3D-printed patient-specific acetabular components in the management of extensive acetabular defects and combined pelvic discontinuity (PD).

METHODS

9 patients underwent revision THA using 3D-printed custom acetabular components to reconstruct extensive acetabular defects. The Paprosky classifications were determined in all patients. The primary outcome measure was the implant-associated failure rate.

RESULTS

1 out of 9 patients suffered an implant-associated complication (11%). The overall implant-associated survival rate was 89%. The overall complication rate was 56%.

CONCLUSIONS

The patient-specific acetabular component technique shows promise for the treatment of patients with severe acetabular defects in revision THA. Further research aimed at reducing costs and improving the complication rate are warranted.

A 2- to 7-Year Follow-Up of a Modular Iliac Screw Cup in Major Acetabular Defects: Clinical, Radiographic and Survivorship Analysis With Comparison to the Literature

BACKGROUND

Inadequate acetabular bone stock is a major issue in total hip arthroplasty, and several treatment options are available. Stemmed cups have been used in this scenario with variable results. A novel modular polyaxial uncemented iliac screw cup (HERM-BS-Sansone cup-Citieffe s.r.l., Calderara di Reno, Bologna, Italy) has been recently introduced to overcome the drawbacks of stemmed cups. In this retrospective study, we report the results of this cup in patients with large acetabular bone defects at 2- to 7-year follow-up.

METHODS

We evaluated a consecutive series of 121 hips (118 revisions and 3 complex primary arthroplasties) treated with this novel cup at a mean follow-up of 46 months. Kaplan-Meier survival analysis was performed with implant revision for any reason as a primary end point. Further survival analysis was performed excluding septic failures. Clinical outcome was assessed with the Harris Hip Score.

RESULTS

There had been 7 reoperations: 1 for aseptic loosening, 5 for deep infection, and 1 for recurrent dislocation. In 5 cases, the cup was removed; estimated survival rate at 5-year follow-up with implant removal for any reason was 95.6% (95% confidence interval = 91-99), and 98.3% (95% CI = 96-100) excluding those failed for infection. Mean Harris Hip Score at latest follow-up was 77 points (range, 44-95; standard deviation = 11.9).

CONCLUSION

The present findings show the short-term efficacy of the iliac screw cup with respect to implant survival. A longer follow-up and a larger number of patients are necessary to confirm the encouraging preliminary results.

Serum Metal Ions with a Titanium Modular Neck Total Hip Replacement System

The goal of this study is to evaluate serum levels of chromium (Cr), cobalt (Co), and titanium (Ti) within the first two years following total hip arthroplasty using a Ti modular neck system. Twenty-five patients were randomized to a metal-on-metal (MoM) bearing with an all CoCr shell, and the remaining 25 received a metal-on-polyethylene (MoP) with a Ti shell. Serum levels demonstrated increases for Cr, Co, and Ti at 1 year (P < .001). MoM had similar Ti levels to MoP hips at 1 year (P=0.11) but lower at 2 years (P=0.03). Results suggest that the passive corrosion (i.e., chemical, pitting, and crevice corrosion) of exposed non-articular metal surfaces may be a greater source of ions than the neck-stem or head-neck interfaces.

Acetabular defect reconstruction in revision hip arthroplasty with a modular revision system and biological defect augmentation

PURPOSE

Revision of failed total hip arthroplasty with severe acetabular bone loss represents a rare but challenging problem. Anatomic reconstruction with biological defect augmentation as solid bone transplants or cancellous bone restores bone stock while providing good component stability. The objective of this study was to present short- to mid-term results of revision total hip arthroplasty with a modular ring system in a consecutive series of patients with severe acetabular bone loss.

METHODS

We retrospectively reviewed 39 consecutive patients (39 hips) with severe acetabular bone loss (Paprosky type 3 A and 3 B) reconstructed with revision total hip arthroplasty using the cementless modular ring system MRS-Titan®. The MRS-Titan® consists of independent ring systems that are adapted modularly to the defect situation. Combined with acetabular defect reconstruction by using cancellous bone in impaction grafting technique, the MRS-Titan® system offers a cement-free revision system that enables defect-adapted customization to individual anatomic matters, bridging of the acetabular bone defect and reconstruction of the centre of rotation. Initial stability of the implant was obtained by screw fixation. Harris hip score and sequential radiographs were used to evaluate clinical and radiographic results.

RESULTS

At an average follow up of 31 months (range 12-69 months) 33 of 39 (84.6 %) of the implants were considered radiographically stable without signs of acetabular migration of more than 2 mm in the horizontal or vertical direction, implant rotation or screw breakage. Complications included six implant failures (15 %). We recorded one aseptic loosening of the MRS prosthesis after 20 months. Five patients (12.8 %) had to undergo revision surgery because of periprosthetic joint infection. Two patients had a dislocation postoperatively. The mean Harris hip score improved from 27 ± 14 points preoperatively to 76 ± 15 points at the time of last follow up.

CONCLUSION

By achieving stable implant fixation and providing potential for biological fixation, treatment of severe acetabular bone loss in revision total hip arthroplasty with the modular ring system MRS-Titan provides a durable solution with good clinical and radiographic results and allows us to accomplish major goals of reconstruction.

Acetabular revision arthroplasty using trabecular titanium implants

PURPOSE

The aim of this study was to evaluate early results of acetabular revisions of total hip replacement using fully cementless trabecular titanium (TT) acetabular modular implants (Delta Trabecular Titanium, Limacorporate, Udine, Italy).

METHODS

Between March 2009 and May 2012 TT was used in 81 revisions. The mean age at the time of revision was 68 years (32-84 years). There were nine patients revised for type 1, 11 for type 2A, 27 for type 2B, six for type 2C, 15 for type 3A and 13 for type 3B acetabular defects according to the Paprosky classification. Frozen morselised bone allografts were used in 53 cases and bulk structural allografts in three cases. Clinical evaluations were made using a modified functional Merle d'Aubigné-Postel score. The mean follow-up period was 38.14 months (24-62 months).

RESULTS

The mean pre-operative Merle d'Aubigné-Postel functional score was 4.7 and 9.8 at the time of last follow-up. There was one revision due to instability of the acetabular component. A cage system-Delta Revision TT-was successfully used in this case. Three cases with Paprosky type 3B defect showed cranial migration of the acetabular component by 6 mm, but stabilised after six months. No dislocations associated with acetabular surgery have occurred in the cohort. There have been no dissociations of the modular component. A fatigue fracture of the hemispherical module occurred in the revised case. No other hardware mechanical failures have been recorded.

CONCLUSIONS

TT cups, hemispherical modules and augments facilitate reliable and reproducible biological fixation in acetabular revision surgery with excellent results. Extended follow-up is necessary to evaluate the long-term performance of TT modular implants.

Cementless dual-mobility cup in total hip arthroplasty revision

PURPOSE

Dislocation is a frequent complication in total hip arthroplasty (THA) revision. Cup fixation is the second concern. In order to know outcomes at two years, we prospectively followed a continuous series of 78 patients to demonstrate that cementless dual-mobility cup (DMC) used in revision THA is safe as regards dislocation risk and bone fixation.

METHOD

We enrolled 78 consecutive patients (79 cases) in a prospective study. Mean interval between index surgery and revision was 12.9 years. Mean age at revision was 75.5 years. Two types of cementless DMC were used: a standard DMC in 68 cases with low-grade bone defect (Paprosky grade 1 and 2), and a specific design reconstruction DMC in 11 cases with severe bone loss (Paprosky grade 3).

RESULTS

At two years of follow-up, 68 patients were reviewed; four were lost to follow-up., and six patients were deceased. We identified three types of situations at risk:standard risk (33 cases), Paprosky grade 1 or 2; medium risk (37 cases), revision for recurrent instability (21), periprosthetic fractures (14) or severe loosening Paprosky grade 3 without femorotomy (2); high risk (nine cases), revision for severe loosening with a femorotomy. One (1.3%) patient dislocated her hip at one month without recurrence. Revision rate for dislocation was 0%; two (2.7%) early mechanical failures occurred.

CONCLUSION

Considering outcomes of this series, cementless DMC can be suggested in THA revision surgery.

Systematic review on outcomes of acetabular revisions with highly-porous metals

PURPOSE

The purpose of this study was to systematically review the literature and report the clinical and radiographic outcomes of highly-porous acetabular cups in revision settings.

METHOD

A literature search of four electronic databases of EMBASE, CINAHL-plus, PubMed, and SCOPUS yielded 25 studies reporting the outcomes of 2,083 revision procedures with highly-porous acetabular components. There was lack of high quality evidence (level I and level II studies) and only two studies with level III evidence, while the remainder were all level IV studies. In addition, a majority of the studies had small sample sizes and had short to mid-term follow-up. The mean age of the patients was 65 years (range, 58-72 years) and the mean follow-up was 3.6 years (range, two to six years). Outcomes evaluated were aseptic survivorship, Harris hip scores, migration rates, incidence of peri-acetabular radiolucencies and radiographic restoration of the hip centre.

RESULTS

The mean aseptic survivorship was 97.2% (range, 80-100%). The Harris hip scores improved from a mean pre-operative score of 42 points, (range, 29-75 points), to a mean postoperative score of 79 points (range, 69-94 points). The mean incidence of cup migration and prevalence of peri-acetabular radiolucencies was 2.4% (range, 0-8.8%) and 4.6% (range, 0-19%), respectively, at final follow-up. The vertical hip centre-of-rotation was restored significantly from a mean of 39.2 mm (range, 27.6-50 mm) pre-operatively, to a mean of 24.1 mm (range, 7.4-47 mm), postoperatively.

CONCLUSION

The short-term clinical and radiographic results of highly-porous metals in revision hip arthroplasty are excellent with a low rate of loosening in the presence of both major and minor bone loss.