Review of the outcomes of complex acetabular reconstructions using a stemmed acetabular pedestal component

Outcomes Following Pedestal Cup Reconstruction of (Impending) Pathological Fractures of the Acetabulum due to Metastatic Bone Disease

Management of periacetabular metastatic bone disease (MBD) is challenging, specifically if associated with bone loss or fracture. The aim of this study was to evaluate the complications and outcomes after undergoing peri-acetabular reconstruction using an 'ice-cream cone' pedestal cup endoprostheses for the most severe cases of (impending) pathological acetabular fractures. Fifty cases with severe periacetabular disease were identified. Acetabular defects were classified using the Metastatic Acetabular Classification (MAC). Pre- and post-operative mobility was assessed using the Eastern Cooperative Oncology Group (ECOG) Performance Status. Pain levels were assessed using a verbal rating scale. Surgical complications and patient survival were analysed; the Prognostic Immune Nutritional Index (PINI) was applied retrospectively to survival. There were 32 females and 18 males with a median age of 65 (41-88). Median post-operative follow-up was 16 months (IQR 5.5-28.5 months). Thirty-nine had complete, and 11, impending pathological fractures. The observed five-year survival was 19%, with a median survival of 16 months (IQR 5.8-42.5 months). Significantly worse survival was observed with PINI scores < 3.0 (p = 0.003). Excluding three perioperative deaths, 13 complications occurred in 12 patients: Implant failure in six patients (four aseptic loosening, one dislocation and one infection). At the final follow-up, mobility and pain levels were improved in 85% and 100%, respectively. Reconstruction of significant pelvic MBD with the 'ice-cream cone' reduces pain and improves mobility. Whilst the mortality rate is high, it remains a reasonable option for bed-bound, immobile patients. We advocate the use of an 'ice-cream cone' prosthesis for selected patients balancing the reported risks with the observed benefits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-024-01917-x.

Acetabular Revision with McMinn Cup: Development and Application of a Patient-Specific Targeting Device

BACKGROUND

Surgeries of severe periacetabular bone defects (Paprosky ≥ 2B) are a major challenge in current practice. Although solutions are available for this serious clinical problem, they all have their disadvantages as well as their advantages. An alternative method of reconstructing such extensive defects was the use of a cup with a stem to solve these revision situations. As the instrumentation offered is typically designed for scenarios where a significant bone defect is not present, our unique technique has been developed for implantation in cases where reference points are missing. Our hypothesis was that a targeting device designed based on the CT scan of a patient's pelvis could facilitate the safe insertion of the guiding wire.

METHODS

Briefly, our surgical solution consists of a two-step operation. If periacetabular bone loss was found to be more significant during revision surgery, all implants were removed, and two titanium marker screws in the anterior iliac crest were percutaneously inserted. Next, by applying the metal artifact removal (MAR) algorithm, a CT scan of the pelvis was performed. Based on that, the dimensions and positioning of the cup to be inserted were determined, and a patient-specific 3D printed targeting device made of biocompatible material was created to safely insert the guidewire, which is essential to the implantation process.

RESULTS

In this study, medical, engineering, and technical tasks related to the design, the surgical technique, and experiences from 17 surgical cases between February 2018 and July 2021 are reported. There were no surgical complications in any cases. The implant had to be removed due to septic reasons (independently from the technique) in a single case, consistent with the septic statistics for this type of surgery. There was not any perforation of the linea terminalis of the pelvis due to the guiding method. The wound healing of patients was uneventful, and the implant was fixed securely. Following rehabilitation, the joints were able to bear weight again. After one to four years of follow-up, the patient satisfaction level was high, and the gait function of the patients improved a lot in all cases.

CONCLUSIONS

Our results show that CT-based virtual surgical planning and, based on it, the use of a patient-specific 3D printed aiming device is a reliable method for major hip surgeries with significant bone loss. This technique has also made it possible to perform these operations with minimal X-ray exposure.

The iliac stemmed cup in reconstruction of the acetabular defects secondary to tumor resection: a systematic review of literature

INTRODUCTION

Stemmed acetabular cups are suitable for reconstruction in case of important bone loss. Nevertheless, their use is not so common, because generally judged very invasive and technically difficult to implant. The aim of the present review is to verify the results of their use and to evaluate indications and complications.

MATERIALS AND METHODS

Literature research was performed in the main healthcare databases; indications, surgical technique, related complications, functional results and implant survival were valued and analyzed for every selected paper.

RESULTS

13 studies were selected, for a population of 424 patients and 428 hips. The main indication was reconstruction after tumor removal; the primary non-oncologic indication was revision for aseptic loosening. The most frequent complications were aseptic loosening and implant failure (16.2%), followed by deep infection (11.3%) and dislocation (9.8%). The average MSTS score was 65.9%; while data regarding functional results for degenerative cases are quite fragmented. The 5-years implant survival was 73.6%.

CONCLUSIONS

Data regarding SAC prostheses are quite rare in the literature; no prospective studies with comparisons with other reconstruction techniques are available so their use is mainly based on the experience of single centers. While data for tumors are more consistent and supported by studies, information on revisions of hip prosthesis implanted for degenerative problems is quite scarce. Preliminary results on the SAC prosthesis as a valid alternative both for tumoral and degenerative revision cases are encouraging. Prospective randomized studies are advocated to value results compared to alternative techniques.

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.

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.

Satisfactory Outcome for a Challenging Case of Infected Native Pelvic Discontinuity with Significant Bone Loss: A Case Report

CASE

This is a challenging case of infected native pelvic discontinuity with massive acetabular bone loss. The infection was persistent despite repeated debridement. A new technique of articulated antibiotic spacer plus Mexican hat antibiotic spacer has been used. A triflanged custom-made implant was used in the second-stage surgery. The 2-year follow-up showed no recurrence of infection and no loosening.

CONCLUSION

Using a Mexican hat spacer is a good option when there is a massive bone loss medially. Custom-made triflanged cup showed to be a viable treatment modality for infected pelvic discontinuity despite the cost of the implant.

Surgical Treatment of Pelvic Discontinuity: A Systematic Review and Meta-Analysis

BACKGROUND

Pelvic discontinuity is a rare condition that is treated with a range of implant constructs. However, surgical failure rates are high, and outcome data are inconsistent. It is therefore difficult to gain a clear picture of whether recently developed constructs (antiprotrusio cage [APC], cup-cage, custom triflange, and porous metal) provide better outcomes in terms of mechanical failure and complications in the short to long terms. This study investigated the failure and complication rates associated with cage constructs and porous metal technologies.

METHODS

A systematic review and meta-analysis were performed according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines to evaluate the studies showing pelvic discontinuity in revision total hip arthroplasty. Data retrieved included the intervention performed, length of follow-up, mechanical failure, and other complication rates (dislocation, infection, neurological, loosening, migration). Study quality was assessed with the Methodological Index for Non-Randomized Studies (MINORS) instrument. Pooled mechanical failure and complication rates were calculated using MetaXL 5.3.

RESULTS

None of the included 30 articles (n = 585 hips) were of high quality. The meta-analyses revealed a mechanical failure rate of 14% for all constructs combined. Custom triflange (5%) and cup-cage (7%) had the lowest mechanical failure rates compared with the commonly used APC (25%) and porous metal (12%). The overall other complication rate was 28%, with cup-cage lower at 21% compared with APC (34%) and custom triflange (28%). Long-term evidence investigating both interventions and porous metal technology is limited.

CONCLUSIONS

Mechanical failure rates for cup-cage and custom triflange were lowest. The other complication rate for cup-cage was lower than the pooled average. The study quality was limited, indicating a need for better studies and/or a registry.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Stemmed acetabular cup as a salvage implant for revision total hip arthroplasty with Paprosky type IIIA and IIIB acetabular bone loss

INTRODUCTION

Certain cases of repeated acetabular loosening with severe bone loss are hardly amenable to reconstruction using a Kerboull-type plate with allograft. This limitation is more likely when the severe bone loss occurs in older adults with significant comorbidities that may require a faster procedure. In these indications, a stemmed acetabular cup may be an alternative, although the outcomes have not been well defined, especially for a version where the peg is coated with porous material and additional screws can be added. This led us to conduct a retrospective study to determine: (1) whether a stemmed cup anchored in the iliac isthmus is a viable alternative in these situations, (2) the complication rate and (3) the revision rate for any reason.

HYPOTHESIS

A stemmed cup anchored in the iliac isthmus is a viable alternative in cases of repeated revision with severe acetabular bone loss.

MATERIALS AND METHODS

We performed a retrospective single-center study. Sixteen Integra™ cups were implanted in 14 patients (mean age 72.8±10.4 years, minimum-maximum: 58-95) who had aseptic acetabular loosening combined with severe acetabular bone loss graded as Paprosky IIIA in 7 hips and IIIB in 9 hips. The patients had undergone a mean of 2.7±1.8 (minimum-maximum: 1-6) procedures (i.e. primary and/or revision arthroplasty) before this cup was implanted. The cup's survivorship at the time of review and the complication rate were determined.

RESULTS

At a mean follow-up of 48.8±23.4 months (minimum-maximum: 7-85), two patients had died and two were lost to follow-up. Six hips experienced one or more complications (37.5%): three infections (18.8%), two mechanical failures (12.5%) and one dislocation (6.7%). The cup had to be removed in three patients (18.8%). These complications required reoperation, thus the cumulative incidence of revision for any reason at 5 years was 31% (95% CI: 11-55%).

CONCLUSION

Despite the high complication and revision rates, we believe the stemmed acetabular cup is a viable alternative in salvage reconstruction procedures.

LEVEL OF EVIDENCE

IV, Retrospective case study.

Coned hemipelvis reconstruction for osteoporotic acetabular fractures in frail elderly patients

Aims

Complex displaced osteoporotic acetabular fractures in the elderly are associated with high levels of morbidity and mortality. Surgical options include either open reduction and internal fixation alone, or combined with total hip arthroplasty (THA). There remains a cohort of severely comorbid patients who are deemed unfit for extensive surgical reconstruction and are treated conservatively. We describe the results of a coned hemipelvis reconstruction and THA inserted via a posterior approach to the hip as the primary treatment for this severely high-risk cohort.

Methods

We have prospectively monitored a series of 22 cases (21 patients) with a mean follow-up of 32 months (13 to 59).

Results

The mean patient age was 79 years (67 to 87), and the mean ASA score was 3.3 (3 to 5). Three patients had high-energy injuries and 18 had low-energy injuries. All cases were associated fractures (Letournel classification: anterior column posterior hemitransverse, n = 13; associated both column, n = 6; transverse posterior wall, n = 3) with medialization of the femoral head. Mean operative time was 93 minutes (61 to 135). There have been no revisions to date. Of the 21 patients, 20 were full weight-bearing on day 1 postoperatively. Mean length of hospital stay was 12 days (5 to 27). Preoperative mobility status was maintained in 13 patients. At one year, mean Merle d’Aubigné score was 13.1 (10 to 18), mean Oxford Hip Score was 38.5 (24 to 44), mean EuroQol five-dimension five-level (EQ-5D-5L) health score was 68 (30 to 92), and mean EQ-5D-5L index score was 0.68 (0.335 to 0.837); data from 14 patients. Mortality was 9.5% (2/21) at one year. There have been no thromboembolic events, deep infections, or revisions.

Conclusion

The coned hemipelvis reconstruction bypasses the fracture, creating an immediately stable construct that allows immediate full weight-bearing. The posterior approach minimizes the operative time and physiological insult in this vulnerable patient population. Early results suggest this to be a safe addition to current surgical options, targeted at the most medically frail elderly patient with a complex displaced acetabular fracture. Cite this article: Bone Joint J 2020;102-B(2):155–161.

The biological acetabular reconstruction with bone allografts in hip revision arthroplasty

BACKGROUND

Reconstructions in case of acetabular bone loss in hip revision arthroplasty are challenging. A few techniques have been proposed, with inconstant outcomes. Biological reconstructions using bone allografts may address the acetabular bone loss and restore the hip anatomy. Aim of this work was the description of the surgical technique and the evaluation of the outcomes using a regional arthroplasty register.

MATERIALS AND METHODS

Minor or massive bone allografting was performed in hip revision arthroplasties in a tertiary center. Bulk allografts were used in severe acetabular bone losses. Fresh-frozen femoral heads were impacted in the bone cavity and porous cups were implanted; multihole sockets were used when necessary. In DeLee A zone, no grafts were used in order to reduce overstress graft resorption. The results were evaluated using a regional arthroplasty register, and a comparison with revisions without bone grafts was performed investigating re-revision rates and reasons for further revisions.

RESULTS

At 10 years, acetabular revisions with bone allografts achieved a similar survival rate than revisions without bone grafts. The re-revisions occurred more frequently in revisions without bone allografts (10.8 vs. 9.7%). In the allograft cohort, septic loosening was lower (0.3 vs. 2.6%), whereas a higher rate of aseptic cup loosening was experienced (2.7 vs. 1.4%).

CONCLUSIONS

Bone allografts may provide a good restoration of the acetabular bone stock and the hip biomechanics. Septic loosening does not seems a major concern, whereas a higher rate of aseptic cup loosening should be expected when bone grafts are used.

[Treatment of acetabular defects with the trabecular metal revision system]

BACKGROUND

The results after acetabular component revision are very heterogeneous, irrespective of the use of established or new components. This could be due to a lack of treatment standards for new revision components. The Trabecular Metal™ (TM) revision system, through its modularity, allows for an individual intraoperative reconstruction of the acetabular defect with a single implant system. It was the aim of this study to investigate the results of acetabular revision with the TMT system taking into consideration the utilized components and the acetabular defect.

METHODS

A total of 200 consecutive isolated revisions of the acetabular component from 2010 until 2012 were retrospectively analyzed from our institutional database. Of the 200 cases, 114 revisions were performed with a combination of different TMT components (wedge and cup, cup and cage). Aseptic cup failure and revision for any reason were the defined endpoints of this study. The acetabular defects were graded according to the Paprosky classification.

RESULTS

The average patient age was 63.6 ± 14.8 years (range 32-85 years) and the average follow-up was 5.3 ± 0.7 years. The overall revision rate, independent of the utilized components, was 4.4% and the revision rate for aseptic failure of the acetabular component was 2.6%. The revision rate for aseptic loosening for Paprosky type I and II defects was 0% and Paprosky type III and IV defects was 12%.

CONCLUSIONS

The modular TMT system shows low revision rates. The modularity of the system allows for a safe and intraoperative adaptation to the individual acetabular defect without the need for extensive preoperative imaging or custom-made implants.

L5 radiculopathy secondary to migration of a revision stemmed acetabular cup

INTRODUCTION

Stemmed acetabular components are used in patients undergoing revision total hip arthroplasty in cases with major acetabular defects or pelvic discontinuity. Conflicting results relating to the survival of the component, and complication rates are reported in the literature. We present a case of L5 radiculopathy secondary to proximal migration of this device.

CASE DESCRIPTION

A 79-year-old man was admitted to our department in 2012 with increasing pain and paresthesias, initially diagnosed as left L5 radiculopathy. In 2002, he had undergone revision surgery due to aseptic loosening of the acetabular component with a stemmed acetabular cup. Radiological findings were severe osteolysis around the acetabular cup with proximal migration. MRI showed osteolysis involving the left L5/S1 facet joint and evidence of soft tissue in the left foramina encasing the L5 radicular nerve. Nerve conduction and electromyography studies revealed chronic L5 radiculopathy.

DISCUSSIONS

This case report illustrates the importance of considering acetabular loosening in a patient presenting with radicular symptoms. If a stemmed acetabular cup is chosen for an acetabular reconstruction, careful surgical technique should be employed in order to achieve durable fixation. If the patient has pelvic discontinuity, other options of reconstruction have showed better outcomes in the literature.

Pelvic reconstruction following resection of malignant bone tumours using a stemmed acetabular pedestal cup

Aims

Pelvic reconstruction after the resection of a tumour around the acetabulum is a challenging procedure due to the complex anatomy and biomechanics. Several pelvic endoprostheses have been introduced, but the rates of complication remain high. Our aim was to review the use of a stemmed acetabular pedestal cup in the management of these patients.

Patients and Methods

The study involved 48 patients who underwent periacetabular reconstruction using a stemmed pedestal cup (Schoellner cup; Zimmer Biomet Inc., Warsaw, Indiana) between 2000 and 2013. The indications for treatment included a primary bone tumour in 27 patients and metastatic disease in 21 patients. The mean age of the patients at the time of surgery was 52 years (16 to 83).

Results

At a median follow-up of 6.6 years (95% confidence interval 4.6 to 8.2), local control was achieved in all patients; 19 patients had died (16 of disease). Complications occurred in 19 patients (40%), of which deep infection was the most common, affecting eight patients (17%). Seven patients (15%) had a dislocation of the hip. Aseptic loosening was found in three patients (6%). Two (4%) underwent hindquarter amputation for non-oncological reasons. The risk of revision, with death being treated as a competing event, was 28% at one year, 39% at five years and 48% at ten years post-operatively. The mean Musculoskeletal Tumour Society Score at final follow-up was 71% (27% to 93%).

Conclusion

This type of reconstruction is a satisfactory option for the treatment of patients with a periacetabular tumour. There remains, however, a high rate of complication, which may be reduced by future modifications of the device such as silver coating and tripolar articulation. Cite this article: Bone Joint J 2017;99-B:841–8.