Radiological evaluation of allograft reconstruction in acetabulum with Ganz reinforcement ring in revision total hip replacement

The Ganz acetabular reinforcement ring shows excellent long-term results when used as a primary implant: a retrospective analysis of two hundred and forty primary total hip arthroplasties with a minimum follow-up of twenty years

PURPOSE

The acetabular reinforcement ring with a hook (ARRH) has been designed for acetabular total hip arthroplasty (THA) revision. Additionally, the ARRH offers several advantages when used as a primary implant especially in cases with altered acetabular morphology. The implant facilitates anatomic positioning by placing the hook around the teardrop and provides a homogenous base for cementing the polyethylene cup. Therefore, the implant has been widely used in primary total hip arthroplasty at our institution. The present study reports the long-term outcome of the ARRH after a minimum follow-up of 20 years.

METHODS

Two hundred and ten patients with 240 primary THAs performed between April 1987 and December 1991 using the ARRH were retrospectively reviewed after a minimum follow-up of 20 years. Twenty-three of 240 hips were lost to follow-up, 110 patients with 124 THAs had deceased without having a revision surgery performed. This left 93 hips for final evaluation. Of those, 75 hips were assessed clinically and radiographically after a mean follow-up of 23.1 years (range 21.1-26.1 years). In 18 cases, clinical and radiographic assessment was omitted because implant revision had been performed prior to the follow-up investigation. The primary endpoint was defined as revision for aseptic loosening.

RESULTS

Out of the 93 hips available for final evaluation, 14 hips were revised for aseptic loosening; another four were revised for other reasons (deep infection n = 2, recurrent dislocation n = 2). The survival probability of the cup was 0.96 (95% confidence interval 0.93-0.99) after 20 years with aseptic loosening as endpoint. Radiographic analysis of the surviving 75 hips showed at least one sign of radiographic loosening in 24 hips. The mean Merle d'Aubigne score increased from 8 points pre-operatively to 15 points at final follow-up (7.5 ± 1.8 vs 15.0 ± 2.3, p < 0.001). The mean HHS was 85 ± 14 at final follow-up. Radiographic loosening did not correlate with the clinical outcome.

CONCLUSIONS

The long-term results of the ARRH in primary THA are comparable to results with standard cemented cups and modern cementless cups. We believe that the ARRH is a versatile implant for primary THA, especially in cases with limited acetabular coverage and altered acetabular bone stock where the ARRH provides sufficient structural support for a cemented cup.

Outcome of cages in revision arthroplasty of the acetabulum: a systematic review

BACKGROUND AND AIM OF THE WORK

To investigate the clinical, radiological and functional outcomes of acetabular revisions with acetabular reinforcement rings and cages.

METHODS

A comprehensive literature study of international databases was performed. Inclusion criteria were cementless revisions, use of reinforcement rings, radiological and clinical follow-up, availability of full text in English, publication between January 1990 and July 2018. In a second further analysis, we selected only studies describing patients with more severe acetabular defects (AAOS 3, AAOS 4, Paprosky III). Data extracted included mean follow-up period, radiographic follow-up, functional scores, implant failures and survival rate.

RESULTS

We included in our review 1327 acetabular revisions described in 28 articles. The most commonly used reinforcement rings were Burch-Schneider ring, the Muller ring and the Ganz ring. Mean follow-up for all patients together was 8.8 years. Clinical or radiological signs of loosening were reported in 191 patients, 83 patients needed further acetabular revision for aseptic loosening and 41 patients received additional surgeries for septic loosening. The mean value of the Harris Hip Score reported at the last follow-up was 76.3. Nineteen articles fulfilled the criteria for further analysis about high-grade acetabular bone defects. We analyzed 649 revisions with mean follow-up period of 8.2 years. Clinical or radiological loosening was reported in 90 patients, additional acetabular revision was performed in 39 patients and 25 patients needed further surgeries for deep infection.

CONCLUSION

Acetabular revisions with cages are characterized by good survival rates and functional scores with a mean follow-up period of 8 years.

Long-Term Results of Acetabular Reconstruction Using Ganz Acetabular Rings

BACKGROUND

Our study examines the long-term results of acetabular reconstruction using the Ganz acetabular reinforcement ring (GRR) in total hip arthroplasty.

METHODS

Between 1998 and 2001, 135 hips (119 revision and 16 primary arthroplasties) were consecutively implanted with a GRR at our hospital. The average age was 65 years (range, 26-90). Clinical and radiographic evaluations were carried out. Long-term survivorship was estimated using a competing risks analysis, and multivariate survivorship using Cox regression model was used to identify risk factors for implant failure.

RESULTS

At a mean follow-up of 16 years (range, 15-18), 3 patients were lost to follow-up and 19 had implant failure: 4 aseptic loosenings without re-revision, 4 septic, and 11 aseptic re-revisions. Survival was estimated at 86% after 16 years (95% confidence interval [CI], 78.5%-90.9%) using radiographic loosening or revision for any reason as the end point. Using aseptic loosening as the end point, the survival was estimated at 91.2% after 16 years (95% CI, 84.5%-95.0%). Multivariate analysis revealed that age at surgery was a significant risk factor for failure of the GRR. With acetabular revision or loosening as the end point, patients ≤60 years had 71.6% (95% CI, 53%-82.8%) and older patients had 92.2% (95% CI, 84%-96.2%) probability of implant survival after a mean 16-year follow-up. The median Harris Hip Scores and Western Ontario and McMaster Universities Osteoarthritis Index scores were 77 and 64.5, respectively, and mean Numerical Pain Rating Scale score was 1.6 at final follow-up.

CONCLUSION

Our long-term study showed acceptable survival and functional results using the GRR in older patients, while young patients had less favorable survival.

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

INTRODUCTION:

This study evaluates mid-term results of acetabular revision using a hemispherical acetabular cup in Trabecular Titanium with a cage construct.

METHODS:

We reviewed 36 acetabular revisions performed with the Delta Revision TT cup in 34 patients (mean age = 75, range: 45-92 years). Acetabular defect types (Paprosky classification) included (1) 2B ( n = 5), (2) 2C ( n = 7), (3) 3A ( n = 15), and (4) 3B ( n = 9). Morcellised bone allografts were used in 24 cases, and synthetic bone used in 11. Outcomes were evaluated using the Harris Hip Score (HHS), and the Verbal Rating Scale (VRS) for pain measurement. X-ray visualisation of cup position was used to discern signs of mobilisation and bone graft incorporation. Survivorship at post-revision follow-up (mean = 39.8; range 12-91.5 months) was calculated.

RESULTS:

HHS increased from 40.5 to 87 ( p < 0.01). 68% of cases were pain free; by comparison, 32% had an average VRS score of 1.9 (range 1-3). The average cup inclination angle was 40.8° (30-52°) postoperatively, compared with 41.2° (30-52°) at follow-up; there were no signs of loosening or mobilisation. Centre of rotation was fully restored in 21 (58.3%) hips. According to Gie classification; bone graft incorporation grades were (1) 3 ( n = 21), (2) 2 ( n = 12) and (3) 1 ( n = 2). The survival rate was 100% for aseptic loosening and 91.7% for any cause of revision.

CONCLUSIONS:

The Delta Revision TT cup promises good clinical and radiographic results at short- to mid-term follow-up, with high rates of survival rate and bone integration.

Revision total hip arthroplasty using the Kerboull acetabular reinforcement device for Paprosky type III defects involving the inferior margin of the acetabulum: a minimum five-year follow-up study

Aims

The purpose of this retrospective study was to evaluate the minimum five-year outcome of revision total hip arthroplasty (THA) using the Kerboull acetabular reinforcement device (KARD) in patients with Paprosky type III acetabular defects and destruction of the inferior margin of the acetabulum.

Patients and Methods

We identified 36 patients (37 hips) who underwent revision THA under these circumstances using the KARD, fresh frozen allograft femoral heads, and reconstruction of the inferior margin of the acetabulum. The Merle d'Aubigné system was used for clinical assessment. Serial anteroposterior pelvic radiographs were used to assess migration of the acetabular component.

Results

At a mean follow-up of 8.2 years (5 to 19.3), the mean Merle d'Aubigné score increased from 12.5 (5 to 18) preoperatively to 16.5 (10 to 18) (p < 0.0001). The survival rate at ten years was 95.3% (sd 4.5; 95% confidence interval (CI) 86.4 to 100) and 76.5% (sd 9.9, 95% CI 57.0 to 95.9) using aseptic loosening and radiological loosening as the endpoints, respectively.

Conclusion

These results show that the use of the KARD with reconstruction of the inferior margin of the acetabulum in revision THA is associated with acceptable clinical results and survival at mid-term follow-up with, however, a high rate of migration of the acetabular component of 21.6%. Cite this article: Bone Joint J 2018;100-B:725-32.

Burch-Schneider ring associated with morselized bone allografts, survival and clinical outcomes after acetabular revision surgery

INTRODUCTION AND OBJECTIVES

Acetabular revision surgery is a challenge due to the appearance of bone defects that make primary fixation of implants difficult when extracting loosened components. Reinforcement rings, such as Burch-Schneider (BS), have been shown to be allies in moderate or severe bone defects. The objective of the study is to evaluate the results and survival of these types of implants in acetabular revision surgery in the medium follow-up.

MATERIAL AND METHODS

Retrospective study on a cohort of 64 patients (67 replacements) with BS rings associated with morselized bone allografts in a 2 years minimum follow-up. Data were collected regarding clinical outcomes, graft incorporation, implant mobilization, survival and complications.

RESULTS

The mean follow-up was 5.06 years (R=2.2-12). The Merle scale improved from 8 points to 15 points at the end of follow-up (P<.0001) with 76.11% of good or excellent results. Reproduction of the anatomical centre of rotation was associated with a better result (P<.05). There was total or subtotal incorporation of the bone allograft in 97% of the patients, although this did not prevent a significant migration of the ring according to Gill criteria in 6 cases. We observed an overall survival of the implant for any cause of 93.4% at 5 years, and 84.6% at 10 years.

CONCLUSIONS

The BS reinforcement ring shows good results in the medium and long term enabling anatomical reconstruction in revision surgery as well as replacement of the bone stock. These results are also comparable and are a vast improvement on other rings.

Revision total hip arthroplasty - Salvage procedures using bone allografts in Japan

Total hip arthroplasty (THA) and hemiarthroplasty have improved hip joint function of patients suffering from hip disease or trauma with excellent clinical results and long-term survivorship. Conversely, there has been an increase in the number of revision surgeries after THA and hemiarthroplasty due to bone deficiency. The reconstruction of deficient bone remains a challenging problem following THA. While performing revision surgery, we have previously classified the preoperative bone deficiency using X-ray, CT and three-dimensional CT imaging according to location and severity of the deficiencies. We then predicted the shape and amount of the required bone allograft and the type of implant. Due to the accepted reconstruction methods of bone deficiency following revision surgeries, it is important to pre-operatively assess the site and size of the bone deficiency to be repaired in the revision THA (re-THA). Bone allograft makes it possible to repair massive bone deficiency, recover bone stock, and improve long-term implant stability. Performing bone allograft will require a bone bank for harvesting, treating, and storing bone in Japan.

Bone Remodeling in Acetabular Reconstruction Using a Kerboull-Type Reinforcement Device and Structural Bone-Grafting in Total Hip Arthroplasty

BACKGROUND

The purpose of this study was to identify the long-term durability of the Kerboull-type reinforcement device (KT plate) in acetabular reconstruction for massive bone defects, assessing the remodeling of structural bone grafts.

METHODS

This study retrospectively evaluated 106 hips that underwent acetabular reconstruction using a KT plate between November 2000 and December 2010. Thirty-eight primary total hip arthoplasties (THAs) and 68 revised THAs were performed, and the mean duration of clinical follow-up was 8 years (5-14 years). Regarding reconstructing the acetabular bone defects, autografts were used in 37 hips, allografts in 68 hips, and A-W glass ceramics in 2 hips.

RESULTS

One hip exhibited radiological migration and no revision for aseptic loosening. The mean Merle d'Aubigné Clinical Score improved from 7.5 points (4-12 points) preoperatively to 10.9 points (9-18 points) at the last follow-up. The Kaplan-Meier survival rate for radiological migration of primary and revised THAs at 10 years was 100% and 97% (95% confidence interval: 96%-100%), respectively. Bone remodeling was evaluated using the radiological demarcation at the bone-to-bone interface, and an improvement of 100% in primary THAs and 94% in revised THAs was observed.

CONCLUSION

For massive bone defects, acetabular reconstruction using the KT plate with a structural bone grafting can yield successful results.

Revision Total Hip Arthroplasty Using an Acetabular Reinforcement Ring With a Hook: A Precise Follow-Up, at Average 11.4 Years, of a Previous Report

BACKGROUND

This study aims at determining the average long-term result of revision total hip arthroplasty (THA) using the acetabular reinforcement ring with a hook (ARRH) and bone grafting in severe acetabular bony defect. Expected 15-year survival of ARRH in revision THA is included in the study.

METHODS

Retrospective review of 48 patients (48 hips) with follow-up duration of average 11.4 years (range, 6.1-21.4 years) was conducted. At each follow-up, Harris hip score was used to assess functional outcome, and radiographic acetabular component osteolysis was measured by DeLee and Charnley classification. Bone defects were assessed preoperatively and intraoperatively using American academy of orthopedic surgeons and Paprosky classification. The common modes of ARRH failures were evaluated. Bone consolidation, presence of heterotopic ossification, and complications such as infection and dislocation were recorded.

RESULTS

The bone defects were varied and included cavitary, segmental, and combined defects without any pelvic discontinuity. Mean Harris hip score improved from 52.6 points preoperatively to 82.0 points postoperatively. Nine acetabular revisions and 3 stem revisions (2 concurrent with acetabular revisions and 1 isolated stem revision) were performed. There were 5 infected cases and 1 patient with recurrent dislocation. The 11.4-year survival of revision THA with ARRH was 71% as the end point for acetabular revision surgery for any reason. The expected 15-year survival of revision THA with ARRH was 60%. The most common failure mode of ARRH was superomedial migration followed by lateral migration.

CONCLUSION

ARRH combined with bone grafting produces relatively good average long-term clinical results.

Radiography versus multidetector computed tomography in assessing graft integration after acetabular reconstruction

PURPOSE

To compare radiography with multidetector computed tomography (MDCT) in the evaluation of graft integration following acetabular reconstruction for failed total hip arthroplasty (THA).

METHODS

Records of 5 men and 6 women aged 60 to 78 (mean, 71.8) years who underwent acetabular reconstruction using structural allografts for severe acetabular deficiency secondary to aseptic loosening (n=9) or septic loosening (n=2) were reviewed. The mean survival time of the THA was 136.4 (range, 12-360) months. Acetabular defects were classified as IIC (n=2), IIIA (n=3), or IIIB (n=6). Structural allografts were fixed with impaction followed by a reinforcement ring (n=10), an antiprotrusio cage (n=2), and/or an oblong cup (n=1) with gentamicineloaded cement. Cup loosening, graft integration, and graft resorption were evaluated using radiography. In addition, graft integration was evaluated using MDCT.

RESULTS

At a mean follow-up of 4.2 (range, 2-11) years, the survival of the acetabular reconstruction was 90.9%. No patient had any signs of infection. One patient underwent reoperation 22 months later for dislocation secondary to abductor deficiency caused by nonunion of the trochanteric fracture. According to radiography, all patients had graft integration. One patient had definitive and another had possible cup loosening. Four patients had minor graft resorption. According to MDCT, graft integration was complete in only one patient, partial >50% in 3, partial <50% in 4, and absent in 2.

CONCLUSION

MDCT is more accurate than radiography in evaluating graft integration following acetabular reconstruction.

Acetabular Reconstruction with Reinforcement Ring and Morsellised Graft: Technique and Medium-term Result

Background

Acetabular bone defects are commonly seen in both primary and secondary total hip arthroplasty, creating difficulties in restoring anatomical hip centres, which results in high mechanical failure rate.

Methods

Total hip arthroplasty with acetabular reinforcement rings were performed in 18 hips in 18 patients from 1996 to 2011 in United Christian Hospital. Both clinical and radiographical assessment were performed during follow-up.

Results

Eight patients died of unrelated diseases with average follow-up of 30.5 months. At the latest follow-up, none of them showed radiographic signs of loosening or migration of implants and none of them required revision surgery. The remaining 10 patients with mean age of 77.9 years (range, 65–88] at the time of operation were followed-up for an average of 67.4 months (range, 11–121). The average Harris hip score was 78.3 (range, 58.5–87). The average vertical and horizontal difference of hip centres was 1.5 mm superiorly ( p = 0.431) and 0.4 mm medially ( p = 0.619) respectively when postoperative hip centres were compared to their contralateral hips. The average inclination of the polyethylene cup was 47.8 degrees (range, 42–58). There was no evidence of radiographic loosening during our follow-up and none of them required revision surgery.

Conclusion

Acetabular reconstruction with the use of acetabular reinforcement rings and morsellised bone grafts showed satisfactory clinical and radiographic results at a medium-term follow-up.

10-Year Survival of Acetabular Reinforcement Rings/Cages for Complex Hip Arthroplasty

Introduction :

Acetabular reinforcement rings/ cages (AR) are commonly used for reconstruction of bone defects in complex hip arthroplasty. The aim of this study was to retrospectively investigate the 10-year survival rate of Ganz reinforcement rings and Burch-Schneider cages used in a single institution.

Material and Methods :

Between September 1999 and June 2002 all ARs, implanted in one institution, were identified. All patients had regular clinical and radiographic follow-up and were included in this study. Their prospectively collected clinical and radiographic data was retrospectively analyzed. In case of death before the 10-year follow-up examination, patient’s families or their general practitioner was contacted by telephone. The main outcome measures were survival of the ARs and kind of revision surgery.

Results :

The 10-year survival rate was 77.7%. At 10-year follow-up, 5/60 (8,3%) patients could not be located and had to be excluded therefore. 27/55 (49,1%) were dead, whereof 22 had no revision of the ARs before death (after a mean of 66 months; range: 0 - 123). Of the remaining 28/55 (50,9%) patients, 23 patients (24 ARs) had no revision of the ARs.

Conclusion :

Despite the high mortality rate of this study’s collective, ARs for complex primary or revision total hip arthroplasty provided predictable long term results.

Level of Evidence :

Clinical investigation.

Contact between the acetabulum and dome of a Kerboull-type plate influences the stress on the plate and screw

We used a three-dimensional finite element method to investigate the conditions behind the Kerboull-type (KT) dome. The KT plate dome was divided into five areas, and 14 models were created to examine different conditions of dome contact with the acetabulum. The maximum stress on the KT plate and screws was estimated for each model. Furthermore, to investigate the impact of the contact area with the acetabulum on the KT plate, a multiple regression analysis was conducted using the analysis results. The dome-acetabulum contact area affected the maximum equivalent stress on the KT plate; good contact with two specific areas of the vertical and horizontal beams (Areas 3 and 5) reduced the maximum equivalent stress. The maximum equivalent stress on the hook increased when the hardness of the bone representing the acetabulum varied. Thus, we confirmed the technical importance of providing a plate with a broad area of appropriate support from the bone and cement in the posterior portion of the dome and also proved the importance of supporting the area of the plate in the direction of the load at the center of the cross-plate and near the hook.

Options for managing severe acetabular bone loss in revision hip arthroplasty. A systematic review

Revision hip arthroplasty in the presence of severe acetabular bone loss is challenging and requires a solid understanding of current techniques. A literature search of multiple databases applying specific criteria revealed a total of 50 articles of level IV scientific evidence comprising 2415 patients (2480 hips) managed with reinforcement devices (roof-reinforcement rings and anti-protrusio cages), custom-made triflanged acetabular components (CTACs), jumbo cups and tantalum metal (TM) systems. Overall, patients had improved postoperative hip scores for each technique. The use of reinforcement devices resulted in a mean revision rate of 8.2% and a mean complication rate of 29.21%. CTACs were associated with a revision rate of 15.9% and had a complication rate of 24.5%. Jumbo cups were revised in 8.8% of patients and had a complication rate of 18.4%. TM systems had an overall revision rate of 8.5% with complications seen in 18.5% of patients. CTACs had considerably higher revision rates compared to the other techniques. Jumbo cups and TM systems had lower complication rates compared to the use of reinforcement devices and CTACs. The most frequently occurring complications seen throughout the series were aseptic loosening, dislocation and infection.

Loosening after acetabular revision: comparison of trabecular metal and reinforcement rings. A systematic review

The best method of revision acetabular arthroplasty remains unclear. Consequently, we reviewed the literature on the treatment of revision acetabular arthroplasty using revision rings (1541 cases; mean follow-up (FU) 5.7 years) and Trabecular Metal, or TM, implants (1959 cases; mean FU 3.7 years) to determine if a difference with regard to revision failure could be determined. Failure rates of the respective implants were compared statistically using a logistic regression model with adjustment for discrepancies in FU time. In our study, TM shows statistically significant decreased loosening rates relative to revision rings for all grades including severe acetabular defects and pelvic discontinuity. The severe defects appear to benefit the most from TM.

Two-stage revision total hip arthroplasty for periprosthetic infections using antibiotic-impregnated cement spacers of various types and materials

Antibiotic-impregnated hip cement spacers of various types and materials have been used in the treatment of periprosthetic hip infections. We developed a handmade spacer by using polymethylmethacrylate (PMMA) and/or α-tricalcium phosphate (α-TCP). In this study, we retrospectively reviewed the surgical outcomes in 36 consecutive patients treated with 2-stage revision total hip arthroplasty by using our antibiotic-impregnated hip cement spacers. We aimed to analyze the infection control and reinfection rates after revision surgery. Moreover, we analyzed the possible predictors of postoperative reinfection. After exclusion of 1 patient who died immediately after the first-stage surgery, infection was controlled in 33 of the 36 hips (success rate, 91.7%). Two of these 33 hips underwent resection arthroplasty. Of the 36 hips that had been treated with the antibiotic-cement spacer, 31 hips (86.1%) were eligible for the second-stage prosthesis re-implantation. The 31 protocol hip joints of patients followed up for >6 months (mean, 48.6 months). Ten of these 31 hips (32.3%) became reinfected. No possible predictor examined differed significantly between the reinfection-positive and reinfection-negative groups. However, spacers consisting of PMMA cement alone were associated with the highest risk of reinfection. Therefore, α-TCP-containing antibiotic-impregnated hip cement spacers might decrease the reinfection rate in patients undergoing re-implantation.