Prediction of Charnley femoral stem aseptic loosening by early post-operative radiological features

Quality of cementing in hemiarthroplasty for elderly neck of femur fractures does not affect short term functional outcomes

INTRODUCTION

Cemented hip hemiarthroplasty is a routine surgical option for elderly neck of femur (NOF) fractures. It is uncertain if quality of cementing has any effect on functional outcomes. The aim of this study was to determine if the quality of cementing would affect short term functional outcomes in elderly neck of femur fractures.

MATERIALS AND METHODS

Retrospective analysis of 637 single-centre cemented hip hemiarthroplasties from 2014 to 2021 was performed. Each post-operative radiograph was double-read by 2 authors (1 resident and 1 fellowship trained surgeon) to determine quality of cementing via the Barrack grading. Disagreements were reviewed by a third reader. Cement grades were grouped as Optimal (Barrack grade A-B), or Suboptimal (Barrack grade C-D). Functional outcomes were compared using mobility (community- or home-ambulant), assistance required for mobility, and Modified Barthel Index (MBI). Surgical parameters were compared between the groups.

RESULTS

There were 429 Optimal and 208 Suboptimal cases of cementing performed. There was no difference in age, American Society of Anesthesiologists score, mobility, assistance required, and MBI score pre-operatively (p > 0.05). Patients in the "Suboptimal" cementing group had a higher Charlson Comorbidity Index (CCI) score (p < 0.001). At 1 year post-operation, there was no significant difference between "Optimal" and "Suboptimal" cementing with regards to the proportion of community ambulators (30.2% vs. 25.7%, p = 0.252), walking independence (independent walkers (19.8% vs.17.3%), independent walkers with aids (41.3%vs.42.1%), walker with caregiver assistance (29.2%vs.33.7%), wheelchair-bound (9.6%vs.6.9%), p = 0.478), and distribution of MBI score (81.1%vs.82.2% achieving MBI > 60, p = 0.767). There was no significant difference in the proportion of patients with postoperative delirium (7.9% vs. 5.8, p = 0.324) or 1-year mortality rates (3.5% vs. 2.9%, p = 0.685). Except for stem design (12.2% tapered vs 20.1% collared; p = 0.011), no other surgical parameters were significantly different. The kappa value for inter-reader agreement was "substantial" at 0.727 (95% CI 0.682-0.772) (p < 0.001).

CONCLUSION

Quality of cementing in cemented hip hemiarthroplasty for elderly NOF fractures does not affect the short-term functional outcomes. In low demand patients and patients at risk of BCIS, optimal cementing may not be necessary to achieve similar short-term functional outcomes. Further studies should be conducted to determine the effect of sub-optimal cementing on long-term functional outcomes.

The use of uncemented stems in femoral neck fractures in elderly patients: A comparative study of 671 cases

INTRODUCTION

The use of cemented stems in elderly patients is associated with the risk of intraoperative embolic complications. Uncemented stems eliminate this risk, but their use is controversial because of the risk of mechanical complications, with estimated subsidence between 3.6 and 30% and periprosthetic fractures between 2.1 and 11% at 6 weeks. A retrospective multicenter comparative study was conducted using a propensity score analysis to evaluate mechanical performances of uncemented stems in femoral neck fractures in elderly patients to (1) compare the risk of mechanical complications and (2) assess the use of metaphyseal-anchored stems for this indication.

HYPOTHESIS

There is no difference in the risk of mechanical complications, intraoperatively or postoperatively, between these stems.

MATERIALS AND METHODS

We conducted a multicenter retrospective comparative study including 358 uncemented and 313 cemented stems. The mean age was 84.5 years [83.9-85.1]. The inclusion criteria were patients 70 years and older and a follow-up of at least 6 weeks. The primary endpoint was a composite endpoint comprised of stem subsidence≥2mm or periprosthetic fracture (up to 3 months postoperatively). The secondary endpoints were infection, stem subsidence≥2mm, and operative time. These endpoints were analyzed using a propensity score to control confounding factors. A secondary analysis used the same endpoints to compare metaphyseal-anchored (short stems) versus Corail-like stems.

RESULTS

After adjusting for the propensity score, we found 11.17% mechanical complications in the uncemented group (n=40, 5.59% subsidence, and 5.59% fractures) versus 13.42% for the cemented group (n=42, 7.99% subsidence, and 5.43% fractures). There was no statistically significant difference between the 2 values (Odds Ratio [OR]=0.64 [95% Confidence Interval [CI]: 0.14-2.85] [p=0.7]). The mortality rate due to cement embolism was 1%. There was no difference in the rate of subsidence (OR=0.55 [95% CI: 0.02-12.5] [p=0.7]), periprosthetic fracture (OR=0.65 [95% CI: 0.13-3.12] [p=0.7]) or infection (OR=0.71 [95% CI: 0.32-1.55] [p=0.4]). However, the operative times were longer in the cemented group (p=0.03 for hemiarthroplasties [mean additional time 16minutes] and p=0.02 for total hip arthroplasties [mean additional time 22minutes]). No difference was observed between the metaphyseal-anchored (short stems) and Corail-like stems regarding operative time, rate of infection, and rate of stem subsidence or periprosthetic fractures.

DISCUSSION

This is one of the first studies to highlight cemented stem subsidence when used for femoral neck fractures in elderly patients. Using uncemented stems in this indication is still warranted, especially since they do not bring about more mechanical complications in the first few months. Metaphyseal-anchored short stems seem to give the same results as "standard" stems. However, these findings need to be assessed in the longer term.

LEVEL OF EVIDENCE

III; retrospective comparative study.

Cessation of Pulsed Lavage During the SARS-CoV-2 Pandemic: The Effect on Hip Hemiarthroplasty Cement Mantles

Background With the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, we were issued with guidance to minimize aerosol-generating procedures and discontinued the use of pulsed lavage for hip hemiarthroplasty. Instead, we used a bladder syringe to wash the femoral canal. The aim of this study was to assess whether this change in practice had a detrimental effect on the quality of the bone cement mantles in patients undergoing cemented hip hemiarthroplasty. Methodology We performed a retrospective review of all patients treated at a tertiary teaching hospital in the United Kingdom (Addenbrookes, Cambridge University Hospitals) presenting with a neck of femur fracture requiring a hemiarthroplasty between October 2019 and June 2020. We retrospectively assessed 100 post-operative radiographs for patients who had received hip hemiarthroplasty following neck of femur fragility fracture (50 before the service change and 50 after). The Barrack classification was used to assess the quality of the bone cement mantle. Results Pre-SARS-CoV-2, 30% of hemiarthroplasties were deemed as being "at risk" of aseptic loosening. During SARS-CoV-2, 64% of hips were deemed as being "at risk." This represents a statistically significant absolute increase of 34% (P < 0.05, the P value is 0.000645). Both clinicians agreed on the classification of hips "at risk" or "not at risk" (i.e., grades C/D and A/B, respectively) in 85% of the cases. Cohen's kappa coefficient was calculated as 0.68, indicating substantial agreement. Conclusions Following our experience of this forced service change, we would discourage abandoning the use of pulsed lavage in future pandemics. We have demonstrated an association between abandoning pulsed lavage and detrimental effects on the procedural quality for hip hemiarthroplasty. Patients treated over this time period will be closely monitored for operative complications. As this was the only equipment change made for this procedure, we have demonstrated its detrimental effect on the procedural quality. Should pulsed lavage be discontinued, patients may need to be counseled for higher risk of early failure and revision surgery and may require long-term radiographic follow-up. In SARS-CoV-2-positive patients, Surgeons should carefully consider the risks and benefits of using pulsed lavage in accordance with the personal protective equipment they have available and the consequential impact on the bone cement mantle quality.

[Predictive factors of aseptic loosening of cemented total hip prostheses]

Introduction

Le descellement aseptique constitue la principale complication à long terme et signe la faillite de la prothèse totale de hanche. Les causes de descellement aseptique sont multiples et souvent intriquées. Le mal positionnement des implants reste le facteur le plus incriminé. D’autres facteurs liés au patient et à la prothèse prédisposent également au descellement mais à des degrés divers.

Méthodes

A travers une étude rétrospective portant sur 64 descellements aseptiques de prothèse totale de hanche, nous avons tenté d’individualiser les facteurs de descellement lié au patient, au type d’implant et à la technique chirurgicale et d’en dégager les recommandations visant à minimiser ce risque. Il s’agissait d’une étude rétrospective analytique portant sur 64 descellements aseptiques. La classification utilisée est celle de la Société Française de Chirurgie Orthopédique et Traumatologique.

Résultats

La moyenne d’âge au moment de la première arthroplastie était de 40 ans. Elle était de 62 au moment du descellement. La tige type Charnley a été implantée dans 55 cas, celle de type Muller dans 9 cas. La pièce cotyloïdienne a été bien positionnée dans 69% des cas avec une inclinaison moyenne de 47,8°. Les tiges étaient remplissantes dans 86% des cas avec un cimentage Grade A dans 60% des cas. Le délai moyen de la survenue du descellement était de 12 ans. 72% des prothèses avaient une survie supérieure à 10 ans. L’analyse statistique des résultats a individualisé les facteurs de risque du descellement que sont: L’âge, l’indexe de masse corporelle, le niveau d’activité, l’inclinaison de la cupule, le déport fémoral et la qualité du cimentage.

Conclusion

Une réduction significative des descellements aseptiques des prothèses totales de hanche ne pourra être obtenue que par une plus grande rigueur dans la sélection des patients, une plus grande sûreté dans l’acte technique et un meilleur choix de l’implant à poser.

Surrogate markers of long-term outcome in primary total hip arthroplasty: A systematic review

Objectives

High failure rates of metal-on-metal hip arthroplasty implants have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices. The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage. We aimed to identify validated surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty (THA).

Methods

We conducted a systematic review of studies evaluating surrogate markers for predicting long-term outcome in primary THA. Long-term outcome was defined as revision rate of an implant at ten years according to National Institute of Health and Care Excellence guidelines. We conducted a search of Medline and Embase (OVID) databases. Separate search strategies were devised for the Cochrane database and Google Scholar. Each search was performed to include articles from the date of their inception to June 8, 2015.

Results

Our search strategy identified 1082 studies of which 115 studies were included for full article review. Following review, 17 articles were found that investigated surrogate markers of long-term outcome. These included one systematic review, one randomised control trial (RCT), one case control study and 13 case series. Validated surrogate markers included Radiostereometric Analysis (RSA) and Einzel-Bild-Röntgen-Analyse (EBRA), each measuring implant migration and wear. We identified five RSA studies (one systematic review and four case series) and four EBRA studies (one RCT and three case series). Patient Reported Outcome Measures (PROMs) at six months have been investigated but have not been validated against long-term outcomes.

Conclusions

This systematic review identified two validated surrogate markers of long-term primary THA outcome: RSA and EBRA, each measuring implant migration and wear. We recommend the consideration of RSA in the pre-market testing of new implants. EBRA can be used to investigate acetabular wear but not femoral migration. Further studies are needed to validate the use of PROMs for post-market surveillance.

Cite this article: T. T. Malak, J. A. J. Broomfield, A. J. R. Palmer, S. Hopewell, A. Carr, C. Brown, D. Prieto-Alhambra, S. Glyn-Jones. Surrogate markers of long-term outcome in primary total hip arthroplasty: A systematic review. Bone Joint Res 2016;5:206–214. DOI: 10.1302/2046-3758.56.2000568.

Radiographic grading of femoral stem cementation in hip arthroplasty

OBJECTIVE:

To determine intra and interobserver agreement of the grading system for femoral cementation in hip arthroplasty proposed by Barrack.

METHODS:

Immediate anteroposterior and lateral postoperative radiographs of 55 primary total hip arthroplasties were assessed by two observers familiar with the use of this grading system. The assessments were performed on two separate occasions by each observer and independently. The statistical analysis measured the Kappa coefficient, which determines the degree of agreement between tests with categorical variables.

RESULTS:

Intraobserver Kappa coefficient varied from 0.43 to 0.68, demonstrating moderate to substantial strength of agreement; interobserver Kappa coefficient varied from 0.19 to 0.44, demonstrating slight to moderate strength of agreement.

CONCLUSION:

Intra and particularly interobserver agreement are limited in this grading system, even when used by trained individuals. Level of Evidence III, Study of nonconsecutive patients; without consistently applied reference "gold" standard.

The migration pattern of the Charnley femoral stem: a five-year follow-up RSA study in a well-functioning patient group

BACKGROUND

Implant stability is considered vital to long-time implant survival in total hip arthroplasty (THA), since loose implants are reported to be a major cause of hip revision. There is an association between early implant micromotion and increased risk of revision. More implant-specific data are needed to establish acceptable levels of early implant movement.

MATERIALS AND METHODS

Thirty-five patients (36 hips) undergoing Charnley THA were followed with repeated clinical, radiographic, and radiostereometric analysis (RSA) over 5 years. Twenty-three patients attended 5 years postoperatively.

RESULTS

The patient group was well functioning based on the radiological and clinical evaluations. The stems constantly moved up to 5 years postoperatively, with subsidence, retroversion, and varus tilt, based on the RSA.

CONCLUSION

Continuous movement of the Charnley stem was observed up to 5 years postoperatively in a well-functioning patient group. The migration data presented herein could be useful when defining acceptable migration limits for certain types of cemented femoral stems.

The condition of the cement mantle in femoral hip prosthesis implantations--a post mortem retrieval study

Despite numerous studies demonstrating the characteristics of the optimal cement mantle in joint replacement, the clinical state of the cement mantle is rarely assessed. A random sample of 214 cemented implanted femoral hip components was retrieved post mortem from Hamburg, Germany, and sectioned to investigate the quality of the cement mantle. The most common observation made in at least one measured region per retrieval was debonding (82% of stems), followed by a thin cement mantle (74%), stem-bone contact (48%), soft tissue at the stem interface (44%), no cement-bone interdigitation (30%), a gap at the stem interface (28%), voids in the cement (22%) and cracks and blood in the cement mantle (<10%). 21% of stems demonstrated complete debonding of the interface. However, distributions of all other defects were local, with less than 10% of stems demonstrating any imperfection in more than 21% of the regions assessed. No progressive damage was observed with implantation duration. The results suggest that current implantation technique may be adequate for proper implant function over the service life in the older patient population. However, for younger and more active patients, perfection of the cementation technique is crucial, particularly in modern implant systems such as resurfacing. The frequency of almost all defects could be further reduced by careful implantation technique, providing the increased service life necessary for the ever younger, more physically demanding, patient population.

Monitoring surgical performance: an application to total hip replacement

RATIONALE, AIMS AND OBJECTIVES

Inadequate surgical implantation of a hip replacement may result in decreased patient satisfaction and reduced implant survival. The objective was to monitor surgical performance in hip replacement.

METHOD

The study took place at a teaching centre. All primary total hip replacements were prospectively included in the series. For each hip replacement, intraoperative technical errors, cup and stem fixation and position, and postoperative complications were recorded. If all items rated were correct, the procedure was considered as correct. The Cumulative Sums (CUSUM) test was used to monitor the performance of the centre. A 90% proportion of successful procedures was considered as adequate performance and a 75% proportion of successful procedures was deemed as inadequate performance. Meetings were conducted to discuss the results of monitoring.

RESULTS

Eighty-three total hip replacements were monitored. Overall, 28 procedures (34%) were considered inadequate. The most potent reasons for inadequate performance were cup positioning and stem fixation. The CUSUM test signalled after the second procedure that performance was inadequate. After the first meeting, despite an improvement was seen, the CUSUM test raised an alarm indicating inadequate performance. The study was stopped after the second meeting because of funding reasons before it could be demonstrated that performance had reached the desired level.

CONCLUSION

This study has demonstrated that implementing a dedicated system to monitor surgical performance in a teaching hospital improves the quality of implantation of total hip replacements. Nonetheless, the target of ninety percent of adequate primary total hip replacement could not be reached and efforts should be continued.

Thirty-year results of a prospective study of Charnley total hip arthroplasty by the posterior approach

We present the results of 228 consecutive Charnley low friction hip arthroplasties, performed in 193 patients, between July 1972 and December 1976. Unusually for this time, all hips were inserted by the posterior approach without a trochanteric osteotomy. All patients were enrolled into a prospective study; both preoperative and postoperative clinical and radiologic findings were recorded. This series was independently reviewed in 1985 (Atrah SGK. Long-term follow-up of Charnley total hip replacement through posterior approach. MSc thesis, University of London, 1987) and again in 2002. The preoperative and perioperative findings were similar to contemporary series. Implant positioning was also assessed. Because of our stable population, only 2 patients were lost to follow-up. Our survivorship results show a 10-year survival of 93% deteriorating to a 30-year survival of 73% (+/-6.1). The survivors were assessed radiologically and scored clinically using the Merle d'Aubigné-Postel score with a mean value of 12. The reason for revision was also recorded. These results are comparable to other studies and justify the use of the posterior approach.