Ultrasonic cement removal in cement-in-cement revision total hip arthroplasty: What is the effect on the final cement-in-cement bond?

[Tips and tricks of cement removal in the case of revision surgery]

BACKGROUND

In Germany, current revision rates after arthroplasty range between 28-37%. In particular, remaining cement residues are causative for additional revision surgery after periprosthetic joint infection, which is why complete cement removal is of high importance. However, the removal of remaining cement residues often confronts the surgeon with technical challenges. Complication-free and complete cement removal requires extensive preoperative preparation in order to develop the best possible surgical strategy.

TREATMENT

Special instrument sets to facilitate cement removal in revision cases are available from various manufacturers. In addition to endoluminal approaches, access enhancements such as extended osteotomies exist to facilitate complete cement removal. Finally, the surgeon should be able to give the indication for an intraoperative procedural change after a defined time interval.

Implications of ageing effects on thermal and mechanical properties of PMMA-based bone cement for THA revision surgery

Loosening and infection are the main reasons for revision surgery in total hip arthroplasty (THA). Removing partially detached cemented implant components during revision surgery remains challenging and poses the risk of periprosthetic bone damage. A promising approach for a gentler removal of partially detached prostheses involves softening the PMMA-based bone cement by heating it above its glass transition temperature (TG), thus loosening the implant-cement bond. It is assumed that the TG of PMMA-based bone cement decreases in-vivo due to the gradual absorption of body fluid. Reliable data on TG are essential to develop a heat-based method for removing cemented implant components during revision surgery. The effect of water absorption was investigated in-vitro by ageing PMMA-based bone cement samples for different periods up to 56 days in both Ringer's solution (37 °C) and air (37 °C and 30% humidity). Subsequently, the TG and Vicat softening temperatures of the samples were determined by differential scanning calorimetry and Vicat tests, respectively, according to prescribed methods. Over the entire ageing period, i.e. comparing one day of ageing in air and 56 days in Ringer's solution, the Vicat softening temperature dropped by 16 °C, while the TG dropped by 10 °C for Palacos® R PMMA-based bone cement. Water absorption over time correlated significantly with the Vicat softening temperature until saturation of the PMMA-based bone cement was reached. Based on the TG and Vicat softening temperature measurements, it can be assumed that in body-aged bone cement, an optimal softening can be achieved within a temperature range of 85 °C-93 °C to loosen the bond between the PMMA-based bone cement mantle and the prosthesis stem. These findings may pave the way for a gentler removal of the implant in revision THA.

Frameworks of wavelength selection in diffuse reflectance spectroscopy for tissue differentiation in orthopedic surgery

Significance

Wavelength selection from a large diffuse reflectance spectroscopy (DRS) dataset enables removal of spectral multicollinearity and thus leads to improved understanding of the feature domain. Feature selection (FS) frameworks are essential to discover the optimal wavelengths for tissue differentiation in DRS-based measurements, which can facilitate the development of compact multispectral optical systems with suitable illumination wavelengths for clinical translation.

Aim

The aim was to develop an FS methodology to determine wavelengths with optimal discriminative power for orthopedic applications, while providing the frameworks for adaptation to other clinical scenarios.

Approach

An ensemble framework for FS was developed, validated, and compared with frameworks incorporating conventional algorithms, including principal component analysis (PCA), linear discriminant analysis (LDA), and backward interval partial least squares (biPLS).

Results

Via the one-versus-rest binary classification approach, a feature subset of 10 wavelengths was selected from each framework yielding comparable balanced accuracy scores (PCA: 94.8 ± 3.47 % , LDA: 98.2 ± 2.02 % , biPLS: 95.8 ± 3.04 % , and ensemble: 95.8 ± 3.16 % ) to those of using all features (100%) for cortical bone versus the rest class labels. One hundred percent balanced accuracy scores were generated for bone cement versus the rest. Different feature subsets achieving similar outcomes could be identified due to spectral multicollinearity.

Conclusions

Wavelength selection frameworks provide a means to explore domain knowledge and discover important contributors to classification in spectroscopy. The ensemble framework generated a model with improved interpretability and preserved physical interpretation, which serves as the basis to determine illumination wavelengths in optical instrumentation design.

Cement-in-cement revision of the femur in infected hip arthroplasty in 89 patients across two centres

AIMS

Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision of hip arthroplasty necessitate removal of all bone cement from the femur. In our two centres, we have been using a cement-in-cement technique, leaving the distal femoral bone cement in selected patients for septic hip revision surgery, both for single and the first of two-stage revision procedures. A prerequisite for adoption of this technique is that the surgeon considers the cement mantle to be intimately fixed to bone without an intervening membrane between cement and host bone. We aim to report our experience for this technique.

METHODS

We have analyzed patients undergoing this cement-in-cement technique for femoral revision in infection, and present a consecutive series of 89 patients. Follow-up was undertaken at a mean of 56.5 months (24.0 to 134.7) for the surviving cases.

RESULTS

Seven patients (7.9%) required further revision for infection. Ten patients died of causes unrelated to their infection before their two-year review (mean 5.9 months; 0.9 to 18.6). One patient was lost to follow-up at five months after surgery, and two patients died of causes unrelated to their hip shortly after their two-year review was due without attending. Of the remaining patients, 69 remained infection-free at final review. Radiological review confirms the mechanical success of the procedure as previously described in aseptic revision, and postoperative Oxford Hip Scores suggest satisfactory functional outcomes.

CONCLUSION

In conclusion, we found that retaining a well-fixed femoral cement mantle in the presence of infection and undertaking a cement-in-cement revision was successful in 82 of the patients (92.1%) in our series of 89, both in terms of eradication of infection and component fixation. These results are comparable to other more invasive techniques and offer significant potential benefits to the patient. Cite this article: Bone Joint J 2022;104-B(2):212-220.

Cement-in-cement technique of the femoral component in aseptic total hip arthroplasty revision: A systematic review of the contemporary literature

Background

Clinical outcomes of cemented femoral stems revisions using the cement-in-cement technique in aseptic conditions after total hip arthroplasty have been widely described.

Methods

The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried.

Results

Twelve articles were included (620 revision THA). Revision rate for complications related to the femoral side was 1.4% at mid-term follow-up (5.4 years). Periprosthetic femoral fracture rate was 1.1%, aseptic loosening of the femoral component 0.3%.

Conclusions

Cement-in-cement revision technique of the femoral component is associated with a high mid-term success rates (98.6%) and is potentially less challenging than other revision techniques.

Systematic Biomechanical Analysis of Prerequisites for Reliable Intraoperative Bonding of Polymethylmethacrylate Bone Cement in Preexisting Cement in Revision Arthroplasty

Removal of a stable cement mantle may be invasive and time consuming and may result in unnecessary damage to bone and surrounding soft tissue. The goal of this study was to investigate the feasibility of the use of polymethylmethacrylate cement on preexisting cement as well as to explore the prerequisites for practical clinical use under standardized laboratory conditions. The strength of the cement-cement interface was evaluated with a 4-point bending to failure test, according to International Organization for Standardization 5833, as well as standardized shear strength, according to American Society for Testing and Materials D732. Various intraoperative cleaning agents were tested to remove simulated contamination with bone marrow. Contamination of the cement-cement interface with bone marrow decreases bending strength, modulus, and shear strength. Removal of the bone marrow with a degreasing agent significantly increases bending strength as well as bending modulus and can increase shear strength up to 9% compared with use of a nondegreasing agent. The cement-cement interface may reach up to 85% of bending strength, 92% of bending modulus, and comparable shear strength compared with a uniform cement block. Meticulous removal of fatty contaminant is important. Use of a degreasing agent further increases the stability of the cement-cement interface. With these precautions, it is safe to assume that the combined molecular and mechanical interlock is sufficient for most clinical applications and will not represent the weakest link in prosthetic revision. [Orthopedics. 2021;44(1):e55-e60.].

The cement-in-cement technique is a reliable option in hip arthroplasty revision surgery: a systematic review

INTRODUCTION

The cement-in-cement technique for revision hip arthroplasty has many potential advantages and has recently gained widespread interest but still lacks evidence to support it. Our aim was to examine the surgical and patient-reported outcomes after cement-in-cement revision hip arthroplasty.

MATERIALS AND METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and EMBASE databases were searched up to February 2019 for original studies reporting the outcomes of revision hip arthroplasty surgeries using the cement-in-cement technique. The methodological quality was assessed using the methodological index for non-randomized studies scale.

RESULTS

Sixteen non-comparative studies met the eligibility criteria, comprising 1899 hips in 1856 patients (72.2 mean age, 37% male), with a mean follow-up of 7.2 years. Most studies reported only primary revisions and focused on the stem component. Intraoperative complications such as femoral or acetabular fractures (5.3%) were low and easily manageable with no relevant sequelae, as were dislocation rates (2.8% of uncomplicated events and 1.6% of cases requiring re-revision). Failure (considered if there was aseptic loosening of the cement-in-cement revised component, 2%), re-revision (9.3%), implant survival and late complication rates were favourable. Functional patient-reported outcomes showed an overall improvement above the minimal clinically important difference at final follow-up.

CONCLUSION

The cement-in-cement technique is a viable option for hip arthroplasty revision surgery with low intraoperative and late complication rates, dislocations and immediate post-operative morbidity, resulting in good functional patient-reported outcomes and favourable medium-term implant survival.