PCL retained is safe in medial pivot TKA-a prospective randomized trial

PURPOSE

Medial pivot (MP) designs resemble native knee kinematics and restore the "natural" kinematics of a knee after total knee arthroplasty (TKA). However, whether to preserve or resect the posterior cruciate ligament (PCL) is still under debate. We inquired whether sacrificing the PCL would improve range of motion, functional outcomes, and limb alignment compared to preserving the PCL in TKA using medial pivot implants (MP-TKA).

METHODS

This prospective, double-blinded, randomized controlled trial consisted of 33 patients (66 knees) undergoing bilateral simultaneous MP-TKA. In one knee, a PCL preservation technique was performed, and in the contralateral knee, the PCL was resected. The primary outcome was postoperative range of motion (ROM). The secondary outcomes were visual analogue scale (VAS) score for knee pain at walking, Knee Injury and Osteoarthritis Outcome Score for symptoms (KOOS-S) and quality of life (KOOS-QoL), Oxford knee score (OKS), and Forgotten Joint Score (FJS), and measurement of the mechanical femoral-tibial axis (mFTA) on X-ray images. All patients were followed up for a minimum of 2 years after surgery.

RESULTS

Patients who underwent MP-TKA with PCL preservation had a similar ROM at 2 years (125.45 ± 7.00 vs. 126.21 ± 6.73, p = 0.65) as those who underwent MP-TKAs with PCL resection. There was also no difference in VAS score (1.94 ± 0.79 vs. 2.00 ± 0.71, respectively, p = 0.51), OKS (39.97 ± 2.01 vs. 39.67 ± 2.03, respectively, p = 0.52), KOOS-S (84.41 ± 3.77 vs. 84.19 ± 3.57, respectively, p = 0.92), KOOS-QoL (82.94 ± 4.76 vs. 82.75 ± 4.70, respectively, p = 0.84), or FJS (72.66 ± 8.99 vs. 72.35 ± 8.64, respectively, p = 0.76) at the 2-year follow-up. No difference in the measurement of the mFTA was found between the two groups (180.27 ± 2.25 vs. 181.30 ± 2.13, respectively, p = 0.59).

CONCLUSION

This study demonstrated that both medial pivot TKA with PCL preservation and PCL resection achieved excellent results. There was no difference at the 2-year follow-up in terms of postoperative ROM, patient-reported outcomes, or radiographic evaluation.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Extended trochanteric osteotomy is a safe procedure in two-stage hip revision: a systematic review of the literature

BACKGROUND

Extended trochanteric osteotomy (ETO) has proved to be an effective technique in complicated stem removal in femoral aseptic loosening or periprosthetic fracture. Debate remains about its safety in periprosthetic joint infection (PJI). The primary aim of this study is to analyze the ETO reinfection and union rate in two-stage hip revision.

MATERIAL AND METHODS

A systematic literature review was performed regarding all studies reporting ETO outcomes in the two-stage revision for hip PJI up to October 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. A literature search was conducted in the following databases: MEDLINE/EMBASE, Scopus, Web of Science, and Cochrane. Quality assessment of the articles was performed using the Methodological Index for Non-Randomized Studies. This systematic review was registered in the International Prospective Registry of Systematic Reviews. Patient demographic, clinical, and surgical data were collected.

RESULTS

This systematic review included and analyzed nine clinical studies with a total of 382 ETO PJI hips in two-stage revision. The overall ETO reinfection rate was 8.9% (34 hips), consistent with the reinfection rate after two-stage revision in patients without ETO. The overall ETO union rate was 94.8% (347 hips), comparable to the ETO union rate in non-septic patients. Compared between a group of patients with ETO PJI and a group of patients with non-PJI ETO, there were no significant differences in postoperative complications, both septic and aseptic, and for postoperative HHS.

CONCLUSION

ETO proved to be a safe and effective procedure in PJI revisions. It may be a viable option in challenging femoral stem removal during the two-stage hip revision in PJI.

LEVEL OF EVIDENCE

IV.

Trabecular titanium cups in hip revision surgery: a systematic review of the literature

Background

Hip revision surgery in extensive acetabular bone defects represents a complex challenge for hip surgeons. The primary goal is to obtain a stable acetabular component and restore the hip biomechanics. Through the years, different prosthetic implants have been developed to perform acetabular revision depending on bone loss location and extension. This systematic review aims to summarize the clinical outcomes and complications reported with trabecular titanium (TT) cups in hip revision surgery.

Methods

A literature search of four databases (PubMed, Embase, Scopus and the Cochrane Database of systematic reviews) was performed according to the PRISMA guideline from January 2008 to December 2022. All studies written in English and reporting the clinical outcome of patients undergoing revision total hip arthroplasty using Delta TT cups were included. The initial screening identified 378 studies. Each eligible clinical article was analyzed according to the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence (LoE), and the papers' methodological quality was evaluated using The Methodological Index for Non-Randomized Studies Criteria (MINORS) score.

Results

Eight clinical studies were included in the analysis. A total of 523 hip revisions were analyzed. Delta TT cups were used in 3.9%, Delta TT one cups in 46.8%, and Delta TT revisions in 49.3%. Paprosky IIIa was the most frequent acetabular bone defect reported in 26.4% of cases. The overall survival rate of TT cups was 93.4%. The dislocation was the most frequent complication in 4.1% of patients, while the prevalence of aseptic loosening was 1.5.

Conclusions

Managing severe acetabular bone defects remains a complex challenge for hip surgeons. Since their introduction, TT cups have exhibited good clinical results, with complication rates in line with or lower than those reported by similar implants.

Outcomes of modular stem for the treatment of periprosthetic femoral fracture: a systematic review of the literature

Background

Periprosthetic femoral fractures (PFFs) are a frequent complication after total hip arthroplasty (THA). Both modular and non-modular tapered fluted titanium (TFT) stems could be used in total hip revisions (THRs). Nevertheless, the most appropriate femoral stem type is still under debate. The current systematic review aims to analyze the survival rate and all causes of stem revision, the overall complication rate and reason for reoperation, and patient reported outcome measures (PROMs) in THR for PFF using the modular tapered titanium stems (MTTS).

Methods

A comprehensive search in four databases, PubMed, Scopus, Embase, and the Cochrane Database of Systematic Reviews databases, was performed, and following the PRISMA guidelines, a systematic review was conducted. Strict inclusion and exclusion criteria were applied, starting from 1,259 studies. The risk of bias was analyzed according to the MINORS tool system. Descriptive statistical analysis was performed for all data extracted.

Results

Eighteen clinical studies were included in the qualitative analysis for a total of 775 patients enrolled. A mean MINORS criteria score of 9.8 [8-12] was reported. The overall survival of MTTS for PFF treatment was 95.4%, with an overall reintervention rate of 10.3% at an average follow-up of 4.5 years. Despite the use of modular components, postoperative hip instability remains the most frequent complication and cause of reintervention in these patients. In addition, a mean postoperative Harris Hip Score (HHS) of 78.1 was reported, which was considered acceptable given the high mean age of 74.1 years at the time of the revision.

Conclusions

Several therapeutic approaches and a wide variety of implants have been described in the literature for PFF management; however, no one solution has proven superior to others in the PFF treatment. MTTS has become a commonly used treatment option for Vancouver B2 and B3 fractures because they provide good clinical and radiological results with a reasonable survival rate. However, the complication rate of MTTS is still high.

Two-stage revision in periprosthetic joint infection of the hip using a new intraoperatively molded articulating spacer design

Purpose

The treatment of periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is still under debate. Two-stage exchange arthroplasty is the most common surgical procedure performed. This study analyzed a new functional articulating hip spacer called "Spaceflex" regarding the mechanical-related complications, the recurrent/persistent infection during the interval period, the overall infection-free survivorship after reimplantation, the overall complication/reoperation after reimplantation and the evaluation of patient-reported outcome measures (PROMs) at three intervals of time: before the first stage, during the interval period, and at the final follow-up after reimplantation.

Methods

A consecutive series of 56 patients with chronic hip PJI undergoing two-stage prosthetic revision using a new intraoperatively molded articulating hip spacer design implanted by the same experienced surgeons was examined from January 2017 to December 2021. The demographic and clinical characteristics of the included patients were analyzed. Specifically, PROMs before the first stage, during the interval period, and at the final follow-up after reimplantation and complications reported during the interval period and after reimplantation were examined.

Results

The new functional articulating hip spacer was characterized by a low mechanical complication rate (5.8%) and an overall two-stage procedure success rate of 90.6% at the last follow-up. PROMs improved with the spacer during the interval period and at the final follow-up. Furthermore, the reinfection rate was in line with other case series with different spacer designs. Finally, low postoperative complication rates after reimplantation have been demonstrated.

Conclusions

Two-stage revision performed with a modular articulating spacer allows patients to preserve satisfactory functional and quality-of-life outcomes in the postoperative period, with a low risk of mechanical complications and without increasing the reinfection rate.

How to Manage Metallosis: A Retrospective Cohort Analysis after Revision Hip Surgery

BACKGROUND

Adverse local tissue reactions to metal debris are due to a metal-on-metal bearing complication caused by micromotions at modular interfaces that induce corrosion of the protective oxide layer. This process could lead to wear, fretting, and abrasion with the release of metal ions locally and systemically, which may cause adverse local reactions in nearby tissues. The aim of this study is to describe a series of patients with painful local adverse tissue reactions secondary to corrosion at the modular neck-body interface, to document the clinical presentation, diagnostic workup, and surgical findings of our research, and to search for a possible correlation between metallosis and infection.

METHODS

A retrospective study of patients with adverse local tissue reactions due to metal surface corrosion was performed. Blood samples were collected to identify erythrocyte sedimentation rate, C reactive protein, and procalcitonin, and a magnetic resonance imaging protocol was performed.

RESULTS

Serum cobalt and chromium levels of the 43 patients tested were significantly higher on average. However, both erythrocyte sedimentation rate and C-reactive protein were significantly elevated. Magnetic resonance imaging showed adverse reactions to metal debris with large soft tissue masses and surrounding tissue damage.

CONCLUSIONS

Corrosion in hip prosthesis can lead to the release of metal ions and debris locally and systemically, resulting in local soft tissue changes. A "tumor-like" debridement can reduce this complication.

Predictive Value of the C-Reactive Protein to Albumin Ratio in 30-Day Mortality after Hip Fracture in Elderly Population: A Retrospective Observational Cohort Study

BACKGROUND

C-reactive protein (CRP) to Albumin ratio (CAR) has been used in multiple clinical settings to predict early mortality. However, there is a lack of evidence on the predictive role of CAR in 30-day mortality after a hip fracture. The purpose of this study was to establish a potential association between CAR and 30-day mortality and to assess if the CAR Receiving Operating Characteristics curve (ROC) can be a reliable predictor of early mortality.

METHODS

We retrospectively reviewed the charts of 676 patients (>65 years) treated for hip fracture between 2006 and 2018. All hip fractures were included. Treatment strategies included closed reduction and internal fixation, open reduction and internal fixation, hemiarthroplasty, or total joint arthroplasty. Statistical analysis included T-test, Pearson correlation for CAR and other markers, ROC curves and area under the curve, Youden Model, and Odds Ratio.

RESULTS

The 30-day mortality rate analysis showed that higher preoperative levels of CAR were associated with higher early mortality. When analyzing the area under the ROC curve (AUROC) for 30-day mortality, the reported value was 0.816. The point of the ROC curve corresponding to 14.72 was considered a cut-off with a specificity of 87% and a sensibility of 40.8%. When analyzing values higher than 14.72, the 30-day mortality rate was 17.9%, whilst, for values lower than 14.72, the 30-day mortality rate was 1.8%.

CONCLUSIONS

Patients older than 65 years affected by a hip fracture with increased preoperative levels of CAR are associated with higher 30-day mortality. Despite a moderate sensibility, considering the low cost and the predictivity of CAR, it should be considered a standard predictive marker.

Current Reconstruction Options in Periprosthetic Fractures Around the Knee

Background:

Periprosthetic fractures are a rare complication after total knee arthroplasty (TKA). However, the incidence of these fractures is growing after the increasing number of TKAs performed every year and the progressive aging of the population. In addition, the surgical treatment and peri-operative management of these complications are demanding, representing a challenge for the orthopedic surgeon.

Significance:

A thorough understanding of these fractures and a correct classification are necessary in order to select the most suitable surgical treatment. The aim of this review was to analyze the epidemiology, classification, diagnosis, surgical treatment, and outcomes of periprosthetic knee fractures in order to give an exhaustive overview.

Results:

Reduction and internal fixation with locking plates or intramedullary nails represents the preferred option in case of a stable prosthetic implant. Conversely, in case of loose tibial and/or femoral component, implant revision is mandatory. Conservative treatment is rarely indicated.

Conclusion:

A deep understanding of the characteristics and patterns of periprosthetic knee fractures, and the determination of the stability of the prosthetic implant are necessary in order to establish the correct treatment.

Mid-term survivorship and clinical outcomes of the medial stabilized systems in primary total knee arthroplasty: A systematic review

Introduction

Medial Pivot Total Knee Arthroplasty was introduced in clinical practice in 1990s to reproduce the in vivo-natural knee kinematics. This design is characterized by an asymmetric constraint profile, with aa highly congruent medial compartment, and a less congruent lateral compartment. Short-term outcomes of the medial pivot systems in primary knee arthroplasty have been widely reported in the current literature, however, only few studies have described results beyond 5-year follow-up.

Objectives

The primary objectives of this systematic review of the literature is to analyze the mid-term studies on medial pivot total knee arthroplasty focusing on the reoperation rate, survivorship and clinical outcome scores.

Methods

The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried for publications from January 1980 to December 2019 utilizing the following keywords: "medial pivot", "medial stabilized", "medial rotating", "medial congruent", medial ball and socket", "arthroplasty", "TKA", "TKR", and "knee surgery".

Results

18 articles met the inclusion criteria for the present study. The average quality was 11.4 for non-comparative studies and 21.7 for comparative studies based on MINORS criteria. A total 2832 knee arthroplasties were included for the final analysis with an average age of 69 years, and an average follow-up of 8.1 years (minimum 5 years). The overall reoperation rate was 2.4%, with periprosthetic joint infection as the leading cause of revision in 0.9% of cases, followed by aseptic loosening in 0.4% of cases. The average Knee Society Score improved to a mean preoperative score of 40.1 to a mean postoperative score of 89.2. The functional knee society score improved from a mean preoperative score of 44.8 to an average postoperative score of 82.9. The global range of motion improved from 104.8° preoperatively to 115.6° postoperatively.

Conclusion

We found that medial pivot system in primary total knee arthroplasty provide overall mid-term survivorship comparable to other standard implasnts. In addition, medial pivot system is associated with better high-end function compared to standard implants.

A formal and automated approach to exploiting multi-stage attacks of web applications

We propose a formal and automated approach that allows one to (i) reason about vulnerabilities of web applications and (ii) combine multiple vulnerabilities for the identification of complex, multi-stage attacks. We have developed WAFEx, an automatic tool that implements our approach and we show its efficiency by applying it to real-world case studies. WAFEx was able to generate, and exploit, previously unknown attacks.

Does negative pressure intrusion cementing technique improve the cement penetration under the tibial component? A comparative retrospective study

Intramedullary suction cementing technique of the tibial component has the theoretical advantage to allow a deeper cement penetration trough the cancellous bone. The aim of this study is to compare the cement penetration under the tibial component between patients that underwent tibial component cementation with or without the use of intramedullary suction. Two-hundred-twenty-four patients underwent primary total knee arthroplasty (TKA) during the study period, One-hundred-twenty-two TKAs using intramedullary suction with negative pressure (55.4%), while one-hundred-two TKAs without intramedullary suction (44.6%). We found that the intra-operative suction during cement application increase the depth of cement penetration better than pulsed lavage alone.

Does the medial pivot knee improve the clinical and radiographic outcome of total knee arthroplasty? A single centre study on two hundred and ninety seven patients

PURPOSE

Total knee arthroplasty (TKA) is a cost-effective surgery with a survival rate higher than 90% after 15 years. Nevertheless, patients are unsatisfied in more than 15% of cases. Medial pivot (MP) prosthetic designs were introduced in late 90's with the aim to reproduce natural knee kinematics. The purpose of this study is to evaluate the survivorship and clinical outcomes of a novel design of MP knee with a minimum follow-up of five years.

METHODS

This is a retrospective review of all patients who underwent primary TKA using the K-Mod dynamic congruence implant (Gruppo Bioimpianti, Peschiera Borromeo, Milan, Italy) between 2012 and 2013 at a single institution. A total of 339 patients (351 knees) were included with a mean age of 74 years (range 41-89). The Knee Society score, the global range of movement, the Western Ontario and McMaster Universities Osteoarthritis score, Forgotten Joint score, and the short-term form 12 health survey were collected. FJS and SF-12 were collected only post-operatively. Radiographic outcomes were evaluated according to the Knee Society's roentgenographic evaluation system. Kaplan-Meyer (KM) curves were performed to evaluate implant survivorship. A two-tailed paired t test was performed to evaluate the differences between pre-operative and post-operative score.

RESULTS

A total 297 patients (315 knees) were available for clinical and radiographic analysis, and the mean follow-up was 66.4 months. A total of 17 patients (17 knees 5.4%) experienced a post-operative complication, and a reoperation was performed in five patients (5 knees 1.6%). Four patients had a periprosthetic joint infection, and two patients had a post-traumatic periprosthetic femoral fracture. The KM survivorship at five years was 98.2% (95% CI 0.96 to 0.99) for revision for any reason. There was a statistically significant improvement (p < 0.05) in all the objective and subjective outcomes measured.

CONCLUSION

The K-Mod dynamic congruence design has shown an excellent clinical, radiographic, and patient-reported outcome in primary TKAs.

Mechanical and elution properties of G3 Low Viscosity bone cement loaded up to three antibiotics

OBJECTIVE

Periprosthetic Joint Infection (PjI) is considered one of the most difficult complication to manage after total knee or hip arthroplasty, with a mean incidence of 1%. Antibiotic loaded bone cement is used as prophylaxis during primary arthroplasty and as local therapy during two-stage revision. The aim of this study is to evaluate the mechanical and elution properties of G3 Low Viscosity Bone Cement (G-21 San Possidonio, Modena, Italy) loaded with different doses of up to three antibiotics (12 specimens).

METHODS

Compressive Strength, Bending Strength and Bending Modulus were evaluated. Cumulative Vancomycin elution by adding different doses of antibiotics was evaluated.

RESULTS

The mean Compressive Strength was 81.55 MPa, the mean Bending Strength was 2161.7 MPa, and the mean Bending Modulus was 36.6 MPa. The highest cumulative Vancomycin elution was observed in specimen 12 (1906.9 mg at 2 weeks). This is the first study, at our knowledge, that analysed how cement mechanical properties, and antibiotic elution kinetics, are modified by adding up to three antibiotic.

CONCLUSION

The results obtained in this pilot study using G3 Low-Viscosity Bone Cement, demonstrated that mechanical properties not decrease significantly by adding large doses of antibiotics, while the Vancomycin elution increase until swelled to twice.

Trabecular Titanium acetabular cups in hip revision surgery: mid-term clinical and radiological outcomes

INTRODUCTION:

Severe acetabular bone loss during revision hip arthroplasty can be restored with different surgical techniques. Best results have been observed using porous tantalum cementless cups. Trabecular Titanium (TT) cups were designed to reproduce the structure, mechanical and biological characteristics of trabecular bone. Few clinical studies have been published with these cups. The aim of this study is to evaluate the clinical and radiological outcome of patients with large acetabular defects (Paprosky IIb or higher) revised using TT cups.

MATERIALS AND METHODS:

64 consecutive patients who underwent revision for total hip arthroplasty (THA) between 2011 and 2015 at our institution were enrolled. All were classified as Paprosky IIb, IIc, IIIa and IIIb. Periprosthetic joint infections and fractures were not included in this study. Radiographic and clinical (Harris Hip Score (HHS)) outcomes were evaluated. Kaplan-Meyer survivorship curve was performed.

RESULTS:

Complete data of 58 patients (mean follow-up 48.3 months) were analysed. 6 patients underwent a further revision (10.3%). Causes of re-revision were instability (5.2%), infection (3.4%) and aseptic loosening (1.7%). No radiolucent lines or signs of migration were observed. Survivorship was 94.8%. HHS Improved from a mean of 36.5-83.7.

DISCUSSION:

TT cups demonstrated encouraging results at mid-term follow-up. Cup modularity represented a helpful tool to restore hip rotation centre and to reduce the risk of dislocation. The capacity of trabecular titanium to induce bone growth and the versatility of modularity, make the Delta TT System a very useful aid for surgeons who are more frequently faced with complex revision.