Bone impaction grafting with trabecular metal augments in large defects in young patients: unravelling a new perspective in surgical technique

Early unrestricted vs. partial weight bearing after uncemented total hip arthroplasty: a systematic review and meta-analysis

Background

The choice of postoperative weight bearing protocol after uncemented total hip arthroplasty (THA) remains controversial. The aim of this study was to assess the efficacy and safety of immediate unrestricted weight bearing (UWB) compared with partial weight bearing (PWB) in patients undergoing uncemented THA.

Methods

Relevant articles were retrieved from electronic databases. Both randomized controlled trials (RCTs) and non-RCTs were included but analyzed separately. All functional and clinical outcomes with at least 2 independent study outcomes were meta-analyzed.

Results

A total of 17 studies were investigated. No adverse effect was found regarding micromotion of the femoral stem with immediate UWB following uncemented THA. There was also no correlation between immediate UWB and failure of ingrowth fixation and higher risks of femoral stem subsidence and surgical revision in RCTs. Harris hip score was better in patients with immediate UWB than those with PWB at 1 year post surgery, but the difference was not statistically significant.

Conclusions

Immediate UWB did not have extra harm compared with PWB in patients undergoing uncemented THA. UWB was not superior to PWB. Considering the improvement of Harris score and the compliance of patients, UWB can be encouraged in THA rehabilitation.

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.

Impaction bone grafting for contained acetabular defects in total hip arthroplasty

BACKGROUND

Acetabular bone loss is a technical challenge in total hip arthroplasty (THA). This study sought to report the functional and radiological results of acetabular reconstruction using impaction bone grafting (IBG) in patients with acetabular bone deficiency undergoing primary or revision THA.

METHODS

In this prospective study, full history taking, preoperative clinical and radiological evaluation, and preoperative planning and templating were performed. The Paprosky classification and the American Academy of Orthopaedic Surgeons classification were used to assess the acetabular deficiencies. Clinical outcomes were assessed utilizing the Harris hip score (HHS) and a 4-question satisfaction questionnaire. Graft incorporation was evaluated in the last follow-up X-rays.

RESULTS

This study included 50 patients with a mean age of 46.7 ± 15.3 years. The THA was primary in 14 (28%) patients and revision in 36 (72%) patients. The mean HHS improved significantly from 28.8 ± 24.1 preoperatively to 76.6 ± 6.1, with a mean follow-up period of 23 months. Overall, 88% of patients were very satisfied. Complete radiological graft incorporation to host bone was achieved in 35 (70%) patients, and the remaining patients had partial incorporation. Complete graft incorporation was associated more frequently with primary THA, autografts, cementless cups, decreased defect size, and decreased graft layer thickness.

CONCLUSIONS

IBG for acetabular reconstruction in THA can achieve excellent clinical and radiological outcomes with a low complication rate.

LEVEL OF EVIDENCE

Level IV.

Partial Two-Stage Exchange for Infected Total Hip Arthroplasty: A Treatment to Take into Account

INTRODUCTION

Two-stage revision is the gold standard for chronic periprosthetic joint infection (PJI). The removal of well-fixed implants, especially the femoral component, can be extremely difficult and additional osteotomies may be needed, which is time-consuming and results in bone stock loss. When the femoral stem is osseointegrated, there is no clear indication for the use of partial two-stage revision. The primary objective was to assess infection eradication after surgery.

METHODS

Retrospective study of specific case series. A total of eight patients with a chronic uncemented PJI, in the setting of complex revision surgeries, were treated with partial two-stage revision, which included selective retention of the well-fixed femoral component and complete acetabular removal. Stem retention was carried out regardless of the bacteria or associated comorbidities.

RESULTS

All patients were re-revision cases with at least two previous surgeries (range, 2-4). Complex revisions were performed in five cases (non-articulated spacer) and simple revisions in three cases (articulated spacer). The minimum follow-up time was 24 months (range, 24-132 months). The infection eradication rate at final follow-up was 100%.

CONCLUSION

Partial two-stage reconstruction is a promising technique for the treatment of chronic PJI in patients with a well-fixed stem and complex re-revision acetabular procedures. Further prospective studies and prolonged follow-ups are required to confirm our results.

Mid-term results in revision hip arthroplasty with impaction bone grafted cup reconstruction for acetabular defects

Acetabular defects are a challenging condition for surgeons in revision THA. A crucial aim is an anatomical restoration of the centre of rotation (COR) through grafts. The aim of this study was to determine the cup survival after biological restoration of acetabular defects in THA and the effect of Paprosky classification, age, BMI, and number of previous operations on cup survival. Retrospectively patients with a cup exchange and an impaction of cortico-cancellous or bulk grafts between 2009 and 2012 were included with a follow up with a minimum of 5 year. Implant failure was defined as radiographic loosening or explantation of the cup. The acetabular defect situation was classified to Paprosky. 82 patients (58 female 70.7%) were included. 26 patients were not available to contact. 56 patients (40 female 71.4%) remained for survival analysis with mean age of 75.6 ± 8 years. Survival of the cup after 5 years was 90% and after 7.8 years 88%. There was no difference in survival concerning defect classification, type of implant or graft, age, BMI, and number of previous operations. Patients on the follow up reached an HHS of 67.4 ± 19, a WOMAC Score of 33.4 ± 25.4 points and an unsatisfactory result in the SF-36. Impaction bone grafting of acetabular defects is a good option with satisfactory biomechanical results and survival for small defects. Predictive factors for cup survival could not be clarified in our study. So, the correct indication, knowing the limits of the methods and the correct choice of implant allow a defect-oriented approach and are decisive for the success of the operation.

Uncemented Cups and Impaction Bone Grafting for Acetabular Bone Loss in Revision Hip Arthroplasty: A Review of Rationale, Indications, and Outcomes

Total hip arthroplasty (THA) is increasingly performed in young patients and the number of revisions is estimated to rise over time. Acetabular osteolysis and bone loss are frequently encountered during revision and may be classified and treated in different ways. Impaction bone grafting (IBG) with morselized allograft offers a viable option. IBG was introduced over 40 years ago in combination with cemented cups, and is also used with uncemented cups. The impacted bone chips act as a void filler to restore bone stock; once incorporated they are substituted by host bone. Surgery entails assessment of the defect, acetabular preparation, preparation of the morselized graft, impaction of the graft, and cup implantation. Satisfactory medium- and long-term results have now been reported in most studies. With the advent of high-porosity cups, indications have been extended, enhancing the potential of IBG, in which primary stability of the cup to the host bone is essential for a successful procedure. Synthetic bone substitutes have also been used in combination with allogenic grafts and may extend the original technique for which long-term studies are warranted.