ACETABULAR RECONSTRUCTION IN PAPROSKY TYPE III DEFECTS

THE CEMENTED DOUBLE MOBILITY CUP IN HIP REVISION: DIFFERENT POSSIBILITIES OF USE

Introduction

The aim of our work is to review those patients who underwent prosthetic hip revision surgery in our hospital considered to be patients at high risk of dislocation or recurrent dislocation, and who underwent a double mobility cemented cup (CMD). Analyzing the different ways to place these cups and the clinical results and reluxations.

Material and methods

The 69 cases comprised 34 men and 35 women with a mean age of 77,39 years. The mean follow-up was 4.7536 years. The type of intervention performed varied according to the cause of the intervention, the acetabular bone stock and the state of the primary cup. In the cases in which there was a good fixation of the primary metalback, we opted to carry out a cementation of the cemented DMC into the existing well-fixed metal acetabular shell, this occurred in 23 cases. In the cases where there was loosening of the primary cup but there was a good bone stock, a CMD was cemented into the bone (21 cases). In the cases where there was a Paprosky type III we cemented a DMC to a Bursch-Schneider reinforcement ring together with the placement of a cancellous bone graft (25 cases).

Results

The clinical evaluation at the end of the follow-up, according to the MD Scale, showed the mean value was 16.454 (SD 0.79472), with a survival at the end of the follow-up of 100% of the placed DMC.

Conclusion

The use of cemented DMC is a good solution in the replacement of THA, especially in cases of reluxation or risk of dislocation due to personal or technical predisposing factors. The use of these DMC cemented can be directly to the bone, into the existing well-fixed metal Shell, or cemented to a reinforcing ring, depending on the acetabular defect. Evidence Level III; Comparative Case Series .

Total Hip Arthroplasty in Patients With Post-Traumatic Bone Defects and Acetabular Deformities

Backround. Total hip replacement in cases of traumatic changes of the acetabulum refers to cases of difficult primary arthroplasty and requires detailed preoperative planning and accurate restoration of anatomical relationships in the operated joint. The aim of the study was to evaluate the structure of pathological changes in the acetabulum in patients with posttraumatic hip arthrosis, to develop a method for their detailed description and to determine the tactics of choosing the type of acetabulum implant. Methods. The results of treatment of 194 patients with the consequences of acetabulum fractures who underwent total hip arthroplasty in the period from 2014 to 2022 were analyzed. The study was conducted in two stages, at the first stage, the structure of pathological changes, such as defect, deformation, changes in the center of rotation and offset (relatively healthy contralateral joint), was analyzed. A method was developed for choosing the tactics of implantation of the acetabulum component, based on a detailed description of the defect and deformation of the acetabulum. The second stage analyzed the results of treatment of patients for whom planning and surgical treatment was carried out in the period from 2020 to 2022 using the proposed method. Results. During the first stage of the study, it was revealed that the magnitude of the change in the indicators of the displacement of the rotation center and offset changes by more than 8 mm. statistically significantly increases the likelihood of complications by 17.9%. The restoration of the rotation and offset center reduces the number of complications by 22.3%. The proposed method makes it possible to statistically reliably restore anatomical relationships in the operated hip joint and reduce the number of complications by 10%. Conclusion. The proposed method allows us to qualitatively and quantitatively describe pathological changes in the bone tissue of the acetabulum. Depending on the degree of displacement of the center of rotation, the walls of the acetabulum and the nature of the defect of the supporting bone tissue, the surgeon can determine the tactics of surgical treatment.

Reconstruction of acetabular defects greater than Paprosky type 3B: the importance of functional imaging

BACKGROUND

3D Surgical planning has become a key tool in complex hip revision surgery. The restoration of centre of rotation (CoR) of the hips and leg length (LL) are key factors in achieving good clinical outcome. Pelvic imaging is the gold standard for planning and assessment of LL. We aimed to better understand if 3D planning is effective at equalising LL when large acetabular defects are present.

MATERIALS AND METHODS

This was a prospective case study of 25 patients. We report the analysis of pre-operative LL status and planned LL restoration measured on CT, in relation to the achieved LL measured post-operatively in functional, weight bearing position. Our primary objective was the assessment of restoration of CoR as well as the anatomical and functional LL using biplanar full-length standing low-dose radiographs; our secondary objective was to evaluate the clinical outcome.

RESULTS

Pre-operative intra-pelvic discrepancy between right and left leg was a mean of 28 mm (SD 17.99, min = 3, max = 60 mm). Post-operatively, the difference between right and left vertical femoral offset (VFO), or CoR discrepancy, was of 7.4 mm on average, significantly different from the functional LL discrepancy (median = 15 mm), p = 0.0024. Anatomical LLD was a median of 15 mm. In one case there was transient foot drop, one dislocation occurred 6 months post-operatively and was treated by closed reduction, none of the patients had had revision surgery at the time of writing. Mean oxford hip score at latest follow up was 32.1/48.

DISCUSSION

This is the first study to investigate limb length discrepancy in functional position after reconstruction of large acetabular defects. We observed that VFO is not an optimal surrogate for LL when there is significant bone loss leading to length inequality, fixed flexion of the knee and abduction deformity.

CONCLUSIONS

Although challenging, LLD and gait abnormalities can be greatly improved with the aid of an accurate surgical planning. Surgeons and engineers should consider the integration of EOS imaging in surgical planning of reconstruction of large acetabular defects.

Outcome and EBRA migration analysis of a reconstruction cage in acetabular revision arthroplasty: a clinical and radiological study

PURPOSE

Restoration cages and bone allografts have been proposed to manage severe acetabular bone defects. We aimed to investigate the migration behaviour of a restoration cup and impacted allograft bone in severe acetabular defects with Einzel-Bild-Röntgen-Analyse (EBRA).

METHODS

Applying a retrospective study design, 64 cases treated between 2009 and 2016 were reviewed. We determined the preoperative Charlson Comorbidity Index (CCI), pre- to postoperative WOMAC score, blood loss and functional outcome. From preoperative x rays, the acetabular deficiencies were classified according to Paprosky. Cup migration analyses were performed with EBRA.

RESULTS

Mean age at surgery was 73 (range: 38-93) years. According to the classification by Paprosky et al., 50% (n = 32) of our patients showed a type III B and 28.1% (n = 18) a type III A defect. Radiological follow-up for migration analysis was 35 (range: 4-95) months. Migration analysis showed a mean cup migration of 0.7 mm (range: 5.7-9.6) medial and 1.8 mm (range: 1.7-12.6) cranial.

CONCLUSION

In conclusion, acetabular restoration cages in combination with bone impaction grafting showed a low revision rate at a mean follow-up of 35 months. Mean cup migration revealed low rates after 2 years and suggested a stable postoperative implant position.

Posterior versus direct anterior approach in revision hip arthroplasty using Kerboull-type plate

Introduction: The purpose of this study was to investigate revision with a Kerboull-type plate through the posterior approach (PA) and direct anterior approach (DAA) and compare the clinical outcome.

Subjects and methods: Fifty-four patients (56 hip joints) underwent revision surgery in which acetabular reconstruction was performed concomitantly using the Kerboull-type plate and allogeneic bone. Revision surgery through DAA was performed in 21 hip joints and these were compared with 34 hip joints treated through PA. There was no significant difference in the patient demographics between the DAA and PA.

Results: There was no significant difference between the operative times in the DAA and PA groups (203.2 ± 43.5 and 211.7 ± 41.8 min). There was a significant difference between the intraoperative blood loss in the DAA and PA groups (503.9 ± 223.7 mL and 703.8 ± 329.6 mL, respectively, p < 0.05). There was no significant difference between the modified Harris Hip Score in the DAA and the PA groups. The loosening of the acetabular component was observed in four cases (11.8%) in the PA group. In the DAA and PA groups, the 5-year survival rates were 100 and 85.7%, respectively. Recurrent dislocation of the hip was observed in six cases (one case in the DAA group (4.8%) and five cases in the PA group (14.7%)).

Conclusions: It was verified that the difference in the surgical approach of acetabular reconstruction concomitantly using the Kerboull-type plate and allogeneic bone graft influenced the postoperative outcome.