Unicompartmental knee replacement: controversies and technical considerations

BACKGROUND

Unicompartmental knee replacement (UKR) is one of the effective interventions for the treatment of symptomatic knee osteoarthritis. Moreover, it has multiple advantages over total knee arthroplasty (TKA), including reduced intraoperative blood loss, decreased risk of transfusion, and faster recovery. This study aimed to discuss critical technical considerations regarding UKR and some of the controversies and updates.

METHODS

We conducted a review to provide an overview of the controversies and technical considerations about UKR in several aspects. Only peer-reviewed articles were included, up to December 2023 using PubMed, Google Scholar, ERIC, and Cochrane database for systematic reviews databases.

RESULT

UKR is associated with superior patient-reported clinical and functional outcomes, as well as shorter hospital stays, fewer postoperative complications, and revealed favorable outcomes in patients' return to sport. The choice between mobile- and fixed-bearing prostheses depends, in part, on the surgeon's preference. The mobile-bearing UKR is a less constrained prosthesis and can potentially result in less wear, but it is more technically demanding. While no significant difference between mobile-bearing versus fixed-bearing prostheses, cementless is superior to cemented design. Furthermore, UKR can be a good alternative for high tibial osteotomy (HTO) and still can be considered after a failed HTO. Lastly, recent reviews have shown a revision rate comparable to that of TKA. This is probably influenced by Improved comprehension of the best indications, patient selection criteria, as well as of the design, materials, and technological advances.

CONCLUSION

UKR treatment for unicompartmental knee osteoarthritis is secure and effective. Based on clinical and functional outcomes, decreased morbidity and mortality, and cost-effectiveness, long-term studies suggest that UKR is superior to TKA. Further investigation in this area is warranted.

A two surgeon series of 1335 patients

BACKGROUND

Routine total hip arthroplasty (THA) using a short cemented stem as compared with a standard length cemented stem may have benefits in terms of stress distribution, bone preservation, stem subsidence and ease of revision surgery. Two senior arthroplasty surgeons transitioned their routine femoral implant from a standard 150 mm Exeter V40 cemented stem to a short 125 mm Exeter V40 cemented stem for all patients over the course of several years. We analysed revision rates, adjusted survival, and PROMS scores for patients who received a standard stem and a short stem in routine THA.

METHODS

All THAs performed by the two surgeons between January 2011 and December 2021 were included. All procedures were performed using either a 150 mm or 125 mm Exeter V40 stem. Demographic data, acetabular implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the New Zealand Joint Registry (NZJR), and detailed survival analyses were performed. Primary outcome was revision for any reason. Reason for revision, including femoral or acetabular failure, and time to revision were also recorded.

RESULTS

1335 THAs were included. 516 using the 150 mm stem and 819 using the 125 mm stem. There were 4055.5 and 3227.8 component years analysed in the standard stem and short stem groups respectively due to a longer mean follow up in the 150 mm group. Patient reported outcomes were comparable across all groups. Revision rates were comparable between the standard 150 mm stem (0.44 revisions/100 component years) and the short 125 mm stem (0.56 revisions/100 component years) with no statistically significant difference found (p = 0.240).

CONCLUSION

Routine use of a short 125 mm stem had no statistically significant impact on revision rate or PROMS scores when compared to a standard 150 mm stem. There may be benefits to routine use of a short cemented femoral implant.

Cemented is not superior to cementless total knee arthroplasty for complications: a propensity score matched analysis

INTRODUCTION

There is continued debate regarding the survivorship and revision rate of cementless versus cemented total knee arthroplasty (TKA) prostheses. This includes the assessment of early revision surgery due to aseptic loosenings and periprosthetic joint infections (PJIs). Studies have not always taken into account the impact of comorbidities, such as diabetes, obesity, and tobacco. Therefore, we compared revisions in a large population of patients undergoing cemented or cementless TKAs at 90 days, 1 year, and 2 years.

METHODS

A review of an administrative claims database was used to identify patients undergoing primary TKA, either cementless (n = 8,890) or cemented (n = 215,460), from October 1, 2015 to October 31, 2020. Revision surgery for PJI and aseptic loosening were identified with diagnosis and associated procedural codes at 90 days, 1 year, and 2 years and then compared between groups. A propensity matched-analysis was performed for age, sex, Charles Comorbidity Index (CCI) > 3, alcohol abuse, tobacco use, obesity, and diabetes. Chi square tests assessed statistical significance of differences in the matched cohorts using odds ratios (ORs) with 95% confidence intervals (CIs). A P < 0.05 was defined as statistically significant.

RESULTS

Cementless TKA was associated with similar revisions rates due to PJIs at 90 days (OR, 1.04, 95% CI 0.79-1.38, p = 0.83), 1 year (OR, 0.93, 95% CI 0.75-1.14, p = 0.53, and 2 years (OR, 0.87, 95% CI 0.73-1.05, p = 0.17) in comparison to the cemented TKA cohort. The odds ratio of revision due to aseptic loosening was similar as well at 90 days (OR, 0.67, 95% CI 0.34-1.31, 0.31), 1 year (OR, 1.09, 95% CI 0.73-1.61, p = 0.76), and 2 years (OR, 1.00, 95% CI 0.73-1.61, p = 0.99).

CONCLUSIONS

This study found a comparable risk of PJI and aseptic loosening in cementless and cemented TKA when controlling for several comorbidities, such as tobacco, diabetes, and alcohol. Therefore, with proper patient selection, cementless TKAs can be performed with expectation of low risks of infections and aseptic loosenings.

Intracapsular hip fractures: A comparative study of cemented and uncemented hemiarthroplasties in the Irish hip fracture database

BACKGROUND

The aim of this study was to analyse the association between use of cement for stem fixation in hip hemiarthroplasty and the outcomes of mobility, mortality, and discharge destination.

METHODS

The Irish Hip Fracture Database was examined from 2016 to 2020 to assess for any difference in post op mobility, 7-day, 14-day and inpatient mortality, and discharge destination.

RESULTS

A total of 7109 hemi-arthroplasties were identified from 2016 to 2020. 71.6 % were cemented (n = 5,172), with 28.4 % uncemented (1,937). There was no difference in day 1 post op mobilisation (79.7 % vs 80.9 %) or cumulative ambulatory score on discharge (2.5 vs 2.4). The mortality rate was equivocal at all time points between the cemented and uncemented groups (7 day (.9 % vs 1.2 %), 14 day (1.9 % vs 2.3 %), inpatient (4 % vs 5.1 %)). There was no difference in length of stay (11 vs 12 days) or discharge to home directly (21 % vs 27 %).

CONCLUSION

The use of cement did not have any significant difference on post op mortality, mobility or discharge destination.

Radiolucent line assessment in cemented stemmed total knee (RISK) arthroplasty: validation of a modernized classification system

BACKGROUND

This study aims to implement and assess the inter- and intra-reliability of a modernized radiolucency assessment system; the Radiolucency In cemented Stemmed Knee (RISK) arthroplasty classification. Furthermore, we assessed the distribution of regions affected by radiolucency in patients undergoing stemmed cemented total knee arthroplasty.

METHODS

Stemmed total knee arthroplasty cases over 7-year period at a single institution were retrospectively identified and reviewed. The RISK classification system identifies five zones in the femur and five zones in the tibia in both the anteroposterior (AP) and lateral planes. Post-operative and follow-up radiographs were scored for radiolucency by four blinded reviewers at two distinct time points four weeks apart. Reliability was assessed using the kappa statistic. A heat map was generated to demonstrate the reported regions of radiolucency.

RESULTS

29 cases (63 radiographs) of stemmed total knee arthroplasty were examined radiographically using the RISK classification system. Intra-reliability (0.83) and Inter-reliability (0.80) scores were both consistent with a strong level of agreement using the kappa scoring system. Radiolucency was more commonly associated with the tibial component (76.6%) compared to the femoral component (23.3%), and the tibial anterior-posterior (AP) region 1 (medial plateau) was the most affected (14.9%).

CONCLUSION

The RISK classification system is a reliable assessment tool for evaluating radiolucency around stemmed total knee arthroplasty using defined zones on both AP and lateral radiographs. Zones of radiolucency identified in this study may be relevant to implant survival and corresponded well with zones of fixation, which may help inform future research.

Comparison of cementless twin-peg, cemented twin-peg and cemented single-peg femoral component migration after medial unicompartmental knee replacement: a 5-year randomized RSA study

BACKGROUND

The component design and fixation method of joint arthroplasty may affect component migration and survival. The aim of this study was to compare fixation of cementless twin-peg (CLTP), cemented twin-peg (CTP) and cemented single-peg (CSP) femoral components of medial unicompartmental knee replacement (UKR).

METHODS

Eighty patients (mean age = 63 years, 48 males) with medial knee osteoarthritis were randomized in three ways to CLTP (n = 25), CTP (n = 26) or CSP (n = 29) femoral UKR components. The patients were followed 5 years postoperatively with RSA, bone mineral density (BMD), PROMs and radiological evaluation of radiolucent lines (RLL), femoral component flexion angle and complications.

RESULTS

At the 5-year follow-up, femoral component total translation was comparable between the three groups (p = 0.60). Femoral component internal rotation was 0.50° (95% CI 0.3; 0.69) for the CLTP group, 0.58° (95% CI 0.38; 0.77) for the CTP group and 0.25° (95% CI 0.07; 0.43) for the CSP group (p = 0.01). BMD decreased peri-prosthetically (range - 11.5%; - 14.0%) until 6-month follow-up and increased toward the 5-year follow-up (range - 3.6%; - 5.8%). BMD change did not correlate with component migration. Lower flexion angle was correlated with higher 5-year subsidence, total translation, varus rotation and maximum total point motion (p = 0.01). Two patients (1 CLTP, 1 CTP) had RLL in the posterior zone. There were two revisions.

CONCLUSION

At 5-year follow-up, fixation of UKA femoral components with twin-peg was not superior to the single-peg design. Cementless and cemented twin-peg femoral components had similar fixation. A lower flexion angle was correlated with higher component migration.

Less pain reported 5 years after cementless compared to cemented unicompartmental knee replacement: an analysis of pain, neuropathy, and co-morbidity scores

PURPOSE

To compare patient-reported pain scores and assess the influence of neuropathy and co-morbidity, on knee pain following cemented and cementless medial unicompartmental knee replacement (UKR) 5 years after surgery.

METHOD

In this longitudinal study, 262 cemented and 262 cementless Oxford UKR performed for the same indications and with the same techniques were recruited. Patients were reviewed at five years, evaluating patient-reported pain and association with clinical outcomes. Intermittent and Constant Osteoarthritis Pain (ICOAP), PainDETECT (PD), Charnley score, Oxford Knee Score (OKS) and American Knee Society Score (AKSS) were compared.

RESULTS

In both cohorts, intermittent pain was more common than constant pain (47% vs 21%). Cementless knees reported significantly less pain than cemented (ICOAP-Total 5/100 vs 11/100, p < 0.0001). A greater proportion of cementless knees experienced no pain at all (ICOAP = 0/100, 61% vs 43%, p < 0.0001) and 75% fewer experienced severe or extreme pain. Pain sub-scores in PD, OKS and AKSS follow this trend. Pain was unlikely to be neuropathic (PD positive: 5.26%), but patients reporting high levels of 'strongest' pain were three times more likely to be neuropathic. Patients with co-morbidities (Charnley C) experienced greater pain than those without (Charnley A+B) across all knee-specific scores, despite scores being knee specific.

CONCLUSION

Both cemented and cementless UKR in this study had substantially less pain than that reported in literature following TKR. Cementless UKR had significantly less pain than cemented UKR in all scores. Two-thirds of patients with a cementless UKR had no pain at all at 5 years, and pain experienced was most likely to be mild and intermittent with no patients in severe or extreme pain. Patients with cementless UKR that had higher levels of pain were more likely to have co-morbidity or evidence or neuropathic pain. It is unclear why cementless UKR have less pain than cemented; further study is necessary.

Removing Cemented Dual Mobility Liners From Acetabular Components: A Technical Tip for a Challenging Surgical Problem

Dislocation remains the leading cause of failure following revision total hip arthroplasty. Dual mobility (DM) constructs, including monoblock cups designed for cementation, reduce but do not eliminate this risk. Cemented DM constructs offer several unique advantages in revision total hip arthroplasty, and as such, they have gained popularity. Despite their advantages, a portion of these implants will require revision for infection or recurrent dislocation. Removal of a cemented DM cup presents numerous challenges, and there is no effective published technique. Here, we present an effective technique for the safe removal of one design of cemented DM cup.

Cemented and hybrid total hip arthroplasty lead to lower blood loss in primary total hip arthroplasty: a retrospective study

BACKGROUND

Little scientific evidence exists on blood loss and transfusion rates depending on the fixation technique. The hypothesis of this study was that the blood loss and transfusion rate are lower in cemented and hybrid total hip arthroplasty (THA) compared to cementless THA.

METHODS

We retrospectively compared a total of 1500 patients who received either cementless, cemented, hybrid or reverse hybrid THA. All patients underwent THA in 2021 at a single orthopedic center in Germany.

RESULTS

The lowest blood loss was found in patients who received a fully cemented THA (695 ± 74 ml). Hybrid THA with a cemented stem showed a blood loss of 845 ± 30 ml and reverse hybrid THA showed the highest blood loss with an average of 994 ± 74 ml. Cementless THA caused an average blood loss of 957 ± 16 ml. There was a significant difference between cementless THA, hybrid THA (cemented stem), and fully cemented THA (p < 0.05). Transfusion rates ranged from 1.3% (cementless THA) to 7.9% (cemented THA) between the groups with a transfusion rate of 2.5% overall.

CONCLUSION

We found significantly lower blood loss in cemented THA and hybrid THA compared to cementless THA. Although blood loss was lower in cemented and hybrid THA, this did not result in lower transfusion rates. This could be due to other confounders such as age, comorbidities, and preoperative anemia.

Standard versus short stem cemented Exeter® when used for primary total hip arthroplasty: a survivorship analysis

AIMS

The aims were to compare the survival of the cemented standard (150 mm) with the short (DDH [35.5 mm offset or less], number 1 short stem [125 mm options of 37.5 mm, 44 mm, 50 mm offset] and revision [44/00/125]) Exeter® V40 femoral stems when used for primary total hip arthroplasty (THA).

METHODS

Patients were retrospectively identified from an arthroplasty database. A total of 664 short stem Exeter® variants were identified, of which 229 were DDH stems, 208 number 1 stems and 227 revision stems were implanted between 2011 and 2020. A control group of 698 standard Exeter® stems used for THA was set up, and were followed up for a minimum of 10 years follow-up (implanted 2011). All-cause survival was assessed for THA and for the stem only. Adjusted analysis was undertaken for age, sex and ASA grade.

RESULTS

The median survival time for the short stems varied according to design: DDH had a survival time of 6.7 years, number 1 stems 4.1 years, and revision stems 7.2 years. Subjects in the short stem group (n = 664) were significantly younger (mean difference 5.1, P < 0.001) and were more likely to be female (odds ratio 1.89, 95% CI 1.50 to 2.39, P < 0.001), compared to the standard group. There were no differences in THA (P = 0.26) or stem (P = 0.35) survival at 5 years (adjusted THA: 98.3% vs. 97.2%; stem 98.7% vs. 97.8%) or 10 years (adjusted THA 97.0% vs. 96.0 %; stem 96.7% vs. 96.2%) between standard and short stem groups, respectively. At 5 years no differences were found in THA (DDH: 96.7%, number 1 97.5%, revision 97.3%, standard 98.6%) or stem (DDH: 97.6%, number 1 99.0%, revision 97.3%, standard 98.2%) survival between/among the different short stems or when compared to the standard group.

CONCLUSION

The Exeter® short stems offer equivocal survival when compared to the standard stem at 5- to 10-year follow-up, which does not seem to be influenced by the short stem design.

Medium-term outcome of the Libra® cemented versus cementless stems in primary dual mobility total hip arthroplasty

INTRODUCTION

Despite the increasing use of cementless stems in total hip arthroplasty, the cemented stem has played a valuable role in the armamentarium of orthopedic surgeons. This study aims to compare two types of Libra® stems SERF, one cemented (Libra® C) and the other cementless hydroxyapatite coated (Libra® HA) that were conducted to analyze the medium-term outcome regarding their behavior and longevity.

METHODS

This is a retrospective study for patients who received primary total hip arthroplasty with Dual Mobility (DM) articulation in the period between January 2014 to January 2020 with a minimum of two years follow-up. Two-hundred hips have been identified in 196 patients. One hundred forty-three Libra® cementless versus fifty-seven Libra cemented stems were implanted and the outcome of these stems is reported. All procedures were performed through the posterior approach and cemented stems were selected for elderly patients with wide medullary canals Dorr Type C. The indications for the index procedure were fractures, avascular necrosis, rheumatoid, and osteoarthritis. One hundred thirty-nine cementless DM cups were used while sixty-one hips had cemented Novae stick cups. Radiological evaluation for cup and stem positions, cement mantle, and radiolucent lines was performed, besides clinical function using the Harris Hip Score.

RESULTS

The average age of patients was 60 ± 14.8. At the latest review, none of the cemented stems was revised or awaiting revision. One cementless stem was revised because of cortical perforation. Five intraoperative fractures were observed in the cementless group, but none of them needed revision or affected the stem stability. Readmission to theatre occurred in four patients to evacuate hematoma in two, a reduction of dislocation in one, and grafting bone lysis in one.

CONCLUSION

Cemented stems have an important role in osteoporotic patients with wide medullary canals with excellent outcomes and minimal risk of fracture.

LEVEL OF EVIDENCE

Level IV.

Cemented versus uncemented stems for revision total hip replacement: A systematic review and meta-analysis

BACKGROUND

The popularity of uncemented stems in revision total hip arthroplasty (THA) has increased in the last decade.

AIM

To assess the outcomes of both cemented and uncemented stems after mid-term follow up.

METHODS

This study was performed following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for systematic reviews and meta-analysis guidelines. Articles were chosen irrespective of country of origin or language utilized for the article full texts. This paper included studies that reviewed revision THA for both cemented or uncemented long stems.

RESULTS

Three eligible studies were included in the meta-analysis. Analysis was conducted by using Review Manager version 5.3. We computed the risk ratio as a measure of the treatment effect, taking into account heterogeneity. We used random-effect models. There were no significant differences found for intraoperative periprosthetic fractures [risk ratio (RR) = 1.25; 95% confidence interval (CI): 0.29-5.32; P = 0.76], aseptic loosening (RR = 2.15, 95%CI: 0.81-5.70; P = 0.13), dislocation rate (RR = 0.50; 95%CI: 0.10-2.47; P = 0.39), or infection rate (RR = 0.99, 95%CI: 0.82-1.19; P = 0.89), between the uncemented and the cemented long stems for revision THA after mid-term follow-up.

CONCLUSION

This study has evaluated the mid-term outcomes of both cemented and uncemented stems at first-time revision THA. In summary, there were no significant differences in the dislocation rate, aseptic loosening, intraoperative periprosthetic fracture and infection rate between the two cohorts.

Two-stage revision for periprosthetic joint infection in cemented total hip arthroplasty: an increased risk for failure?

BACKGROUND

The impact of the prior fixation mode on the treatment outcome of chronic periprosthetic joint infection (PJI) of the hip is unclear. Removal of cemented total hip arthroplasty (THA) is particularly challenging and residual cement might be associated with reinfection. This study seeks to compare the results of two-stage revision for PJI in cemented and cementless THA.

METHODS

We reviewed 143 consecutive patients undergoing two-stage revision THA for PJI between 2013 and 2018. Thirty-six patients with a fully cemented (n = 6), hybrid femur (n = 26) or hybrid acetabulum (n = 4) THA (cemented group) were matched 1:2 with a cohort of 72 patients who underwent removal of a cementless THA (cementless group). Groups were matched by sex, age, number of prior surgeries and history of infection treatment. Outcomes included microbiological results, interim re-debridement, reinfection, all-cause revision, and modified Harris hip scores (mHHS). Minimum follow-up was 2 years.

RESULTS

Compared with PJI in cementless THA, patients undergoing removal of cemented THA had increasingly severe femoral bone loss (p = 0.004). Patients in the cemented group had an increased risk for positive cultures during second-stage reimplantation (22% compared to 8%, p = 0.043), higher rates of reinfection (22% compared to 7%, p = 0.021) and all-cause revision (31% compared to 14%, p = 0.039) compared to patients undergoing two-stage revision of cementless THA. Periprosthetic femoral fractures were more frequent in the group of patients with prior cementation (p = .004). Mean mHHS had been 37.5 in the cemented group and 39.1 in the cementless group, and these scores improved significantly in both groups (p < 0.01).

CONCLUSION

This study shows that chronic infection in cemented THA might be associated with increased bone loss, higher rates of reinfection and all-cause revision following two-stage revision. This should be useful to clinicians counselling patients with hip PJI and can guide treatment and estimated outcomes.

Cementless Compared to Cemented Total Knee Arthroplasty is Associated With More Revisions Within 1 Year of Index Surgery

Background

Cementless total knee arthroplasties (TKAs) have gained renewed interest due to improved implant designs and lower rates of revision than its cemented counterparts. The purpose of this study was to compare revision rates between cemented vs cementless TKAs within 1 year of primary arthroplasty.

Methods

This was a retrospective review from the PearlDiver Patient Record Database. International Classification of Diseases and Current Procedural Terminology codes were used to identify patients who had undergone cemented and cementless TKAs and subsequent surgical revisions. An unadjusted univariate analysis of patient demographics, Charlson Comorbidity Index score, and surgical revisions at 90 days and 1 year after TKA was performed using chi-squared testing. Multivariate logistic regression analyses were subsequently performed for 1-year surgical complications requiring revision.

Results

Of 324,508 patients, 312,988 (96.45%) underwent cemented TKAs, and 11,520 (3.55%) underwent cementless TKAs. Patients undergoing cementless TKA tended to be younger than patients undergoing cemented TKA (63.67 ± 9.15 cementless vs 66.22 ± 8.85 cemented, P < .001). Univariate chi-squared testing showed that cementless patients were more likely to require 1-component femoral or tibial revision at 90 days and 1 year, irrigation and debridement at 90 days and 1 year, and arthroscopy with lysis of adhesions at 1 year only. Similar findings were observed for these 3 revision procedures at 1 year after correcting for age, gender, and Charlson Comorbidity Index score using multivariate logistic regression analysis as cementless TKA patients had higher odds ratios for each of the revisions.

Conclusions

Small but significant differences were found in surgical revisions among cementless TKAs when compared to cemented TKAs within 1 year of the index procedure.

Uncemented Hemiarthroplasty in Displaced Femoral Neck Fractures is associated with Higher Perioperative Surgical Complications but Lower Medical Complications: Analysis from the National Inpatient Database

Objectives

This study aimed to analyze and compare the perioperative outcomes of cemented and uncemented hemiarthroplasty in elderly patients with displaced femoral neck fractures by utilizing the data from the National Inpatient Sample database.

Methods

Data from the National Inpatient Sample Database was analyzed to identify patients who underwent hemiarthroplasty following a displaced femoral neck fracture (cemented and uncemented. Demographic data, comorbidities, length of stay, total charges, and perioperative complications were analyzed.

Results

27390 patients were identified in the cemented group and 29406 in the uncemented group. The patients who underwent uncemented hemiarthroplasty demonstrated a higher incidence of prosthetic dislocation (Odds Ratio (OR) 3.348, p < 0.001), periprosthetic mechanical complications (OR 2.597, p < 0.001), wound dehiscence (OR 2.883, p < 0.001), superficial surgical site infection (OR 2.396, p = 0.043), deep surgical site infection (OR 1.686, p < 0.001), and periprosthetic fractures (OR 2.292, p < 0.001) as compared with patients who underwent cemented hemiarthroplasty. However, patients with uncemented fixation demonstrated a lower incidence of death (OR 0.567, p < 0.001), pulmonary embolism (OR 0.565, p < 0.001), deep vein thrombosis (DVT) (OR 0.746, p < 0.001), myocardial infarction (OR 0.772, p = 0.025) and blood loss anemia (OR 0.869, p < 0.001) as compared with cemented fixation.

Conclusion

Our study on displaced femoral neck fractures utilizing the National Inpatient database found that uncemented hemiarthroplasty was associated with a higher incidence of perioperative surgical complications. Cemented hemiarthroplasty, however, was associated with a statistically significant higher rate of death, pulmonary embolism, deep vein thrombosis, and myocardial infarction.

The natural history of radiolucencies following cemented unicompartmental knee arthroplasty at 7 years

INTRODUCTION

Radiolucent lines (RLLs) following unicompartmental knee arthroplasty (UKA) can be concerning as aseptic loosening remains a cause of failure in UKA. The aim of our study was to report on the history of RLLs surrounding the components in a cemented medial compartment fixed-bearing UKA as well as the long-term functional outcomes in this group of patients.

MATERIAL AND METHODS

In this retrospective consecutive case-series, twenty-eight patients (37 knees) were treated with medial, fixed-bearing cemented unicompartmental knee arthroplasty. At average final follow-up of 7.1 years, 36 knees were available for review. Radiographs were taken at six weeks, one year, and final follow up. RLLs were measured using a novel modification to the Knee Society scoring (KSS) system.

RESULTS

At six-weeks, we identified RLLs in 26 tibias and two femurs out of 37 total knees. At one-year, four additional tibias and both femurs showed some progression of their radiolucencies but were < 2 mm total. At final follow-up, 31 of the 36 tibias (86.1%) and five of the 36 femurs (13.9%) had any RLLs. On the tibial side, RLLs were most common in medial/lateral and anterior/posterior aspects of the tibial tray with few found centrally. On the femoral side, the posterior femoral cut accounted for the most RLLs of any zone at all time points. KSS averaged 93.8 at final follow-up and none of the patients required revision surgery.

CONCLUSION

RLLs are common following cemented, fixed-bearing UKA. Many seem to progress slowly up to one year but not thereafter. There does not appear to be any association between the presence of these radiolucencies and long-term follow-up function in this group of patients.

Periprosthetic femoral fractures around the original cemented polished triple-tapered C-stem femoral implant: a consecutive series of 500 primary total hip arthroplasties with an average follow-up of 15 years

INTRODUCTION

The true incidence of periprosthetic femoral fracture (PFF) around cemented polished taper-slip implants remains largely unknown. Registries usually only capture PFFs that result in revision, missing those managed non-operatively or treated by open reduction and internal fixation (ORIF). This study reports the long-term rate of PFF with the original triple-tapered C-stem femoral implant.

MATERIALS AND METHODS

A prospective review of a consecutive series of 500 primary total hip arthroplasties (THAs) performed at a single centre between March 2000 and December 2005, with average follow-up of 15 years (12-19 years).

RESULTS

There were 500 consecutive THAs in 455 patients. Seven PFFs (1.4%) occurred in seven patients at an average of 7.9 years (range 2-11.5) from the primary arthroplasty. Five PFFs were managed by ORIF, one Vancouver B3 fracture was revised for a loose implant and one patient was treated non-operatively. Average age at primary operation was 74 years (67-87) and BMI averaged 27.3 (22-31). There was no typical fracture pattern and no statistically significant associations with patient demographics (age, gender, BMI, diagnosis) or prosthetic details (size, offset, alignment, cement mantle, subsidence). Survivorship to the occurrence of PFF was 99% (97.3-99.6%) at 10 years and 97.8% (95.5-99.0%) at 15.

CONCLUSION

A PFF rate of 1.4% at an average follow-up of 15 years represents the true incidence of PFF with the use of the original triple-tapered C-Stem femoral implant, similar to that of published Exeter series (1.85%) but lower than the CPT (3.3%).

Favorable revision-free survivorship of cemented arthroplasty following failed proximal femoral nail antirotation: a case series with a median follow-up of 10 years

BACKGROUND

Given the ever-increasing rate of failure related to proximal femoral nail antirotation (PFNA), it is expected that an increasing number of PFNA individuals will undergo conversion to total hip arthroplasty (THA). The long-term survivorship of conversion of the initial PFNA to cemented THA is still debated. The aim of this retrospective study was to assess the long-term revision-free survivorship of cemented THAs after initial failures of PFNA in geriatric individuals.

METHODS

Consecutive geriatric individuals who underwent secondary cemented THA after initial PFNA fixation from July 2005 to July 2018, were retrospectively identified from three medical centres. The primary outcome was revision-free survivorship estimated using the Kaplan-Meier method and Cox proportional hazards regression with revision for any reason as the endpoint; secondary outcomes were functional outcomes and key THA-related complications. Follow-ups occurred at 3 months, 6 months, 12 months and then every 12 months after conversion.

RESULTS

In total, 186 consecutive patients (186 hips) were available for study inclusion. The median follow-up was 120.7 months (60-180 months) in the cohort. Kaplan-Meier survivorship with revision for any reason as the end point showed that the 10-year revision-free survival rate was 0.852 (95% confidence interval [CI], 0.771-0.890). Good functional outcomes were seen, and the HHS decreased markedly over the 24th month to the final follow-up interval from 92.2 to 75.1 (each p < 0.05). The overall rate of key THA-related complications was 16.1% (30/186).

CONCLUSION

Cemented THA executed following initial PFNA failure may yield satisfactory revision-free survival and, at least for the initial 10 years after conversion, good functional outcomes and a 16.1% complication rate of key THA-related complications, which supports the trend towards increased use of cemented THA.

uncemented reverse total shoulder arthroplasty for proximal humerus fractures: a systematic review

BACKGROUND

Reverse total shoulder arthroplasty is an established treatment method for comminuted proximal humerus fractures. Both cemented and uncemented techniques exist, with uncemented reverse total shoulder offering many theoretical advantages, including improved biologic fixation, absence of cement related complications, and ease of revision if necessary. There are few studies comparing the outcomes of the two techniques.

METHODS

The study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A search for studies assessing clinical outcomes of reverse total shoulder arthroplasty for proximal humerus fractures was performed of PubMed, Embase, Web of Science, and Cochrane Library. Main outcomes included Constant Score (CS), American Shoulder and Elbow Surgeons (ASES) score, and complication rate. Inclusion criteria were as follows: indication for arthroplasty was fracture; minimum one year follow up; article in English. Exclusion criteria were as follows: review articles; biomechanical or cadaver studies. Quality analysis was performed using the Cochrane Risk of Bias tool (RoB 2) and the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) tool.

RESULTS

A total of 682 studies were identified through the initial search, with 36 studies meeting all inclusion criteria. There were 24 studies investigating cemented technique, 10 studies examining uncemented technique, and two studies involving both techniques. There was no difference in mean follow up between patients receiving a cemented vs. uncemented rTSA (32.3 months vs. 30.6 months, p = 0.06). Patients who received a cemented rTSA had a significantly higher Constant-Murley score than those who received an uncemented rTSA (59.4 vs 55.9, p < .001). There was no difference between the two groups when comparing ASES Scores (77.5 vs 78.6, p = 0.54) and overall complication rates (11.1% vs 11.8%, p = 0.23).

CONCLUSION

Both cemented and uncemented rTSA are both valid options for treating acute proximal humerus fractures. Cemented rTSA may portend slightly improved clinical outcomes with similar overall complication rates compared to uncemented rTSA for proximal humerus fractures.

Comparing modern uncemented, hybrid and cemented implant combinations in older patients undergoing primary total hip arthroplasty, a New Zealand Joint Registry study

BACKGROUND

Multiple joint registries have reported better implant survival for patients aged > 75 years undergoing total hip arthroplasty (THA) with cemented implant combinations when compared to hybrid or uncemented implant combinations. However, there is considerable variation within these broad implant categories, and it has therefore been suggested that specific implant combinations should be compared. We analysed the most common contemporary uncemented (Corail/Pinnacle), hybrid (Exeter V40/Trident) and cemented (Exeter V40/Exeter X3) implant combinations in the New Zealand Joint Registry (NZJR) for patients aged > 75 years.

METHODS

All THAs performed using the selected implants in the NZJR for patients aged > 75 years between 1999 and 2018 were included. Demographic data, implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the NZJR, and detailed survival analyses were performed. Primary outcome was revision for any reason. Reason for revision, including femoral or acetabular failure, and time to revision were recorded.

RESULTS

5427 THAs were included. There were 1105 implantations in the uncemented implant combination group, 3040 in the hybrid implant combination group and 1282 in the cemented implant combination group. Patient reported outcomes were comparable across all groups. Revision rates were comparable between the cemented implant combination (0.31 revisions/100 component years) and the hybrid implant combination (0.40 revisions/100 component years) but were statistically significantly higher in the uncemented implant combination (0.80/100 component years). Femoral-sided revisions were significantly greater in the uncemented implant combination group.

CONCLUSION

The cemented implant and hybrid implant combinations provide equivalent survival and functional outcomes in patients aged over 75 years. Caution is advised if considering use of the uncemented implant combination in this age group, predominantly due to a higher risk of femoral-sided revisions. The authors recommend comparison of individual implants rather than broad categories of implants.

Comparing uncemented, hybrid and cemented primary total hip arthroplasty in young patients, a New Zealand Joint Registry study

BACKGROUND

Despite increasing use of uncemented implants in young patients undergoing total hip arthroplasty (THA), there is minimal evidence for specific implant combinations in this group. We analysed the most commonly used uncemented (Corail-Pinnacle), hybrid (Exeter-Trident/Tritanium), and fully cemented (Exeter) implant combinations in the New Zealand Joint Registry (NZJR) in patients aged under 40 and between 40 and 55 years.

METHODS

All THAs recorded in the NZJR between 1999 and 2018 were included. The 40-55 and < 40 age groups were analysed separately. Demographic data, implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the NZJR, and detailed survival analyses were performed. The primary outcome was revision for any reason.

RESULTS

We identified 4152 THAs in the 40-55 group and 422 in the < 40 group. In the 40-55 group, revision rates and patient-reported outcome measure scores were comparable between the uncemented implant combination (0.70/100 component years) and the hybrid implant combination (0.62/100 component years), whereas the cemented implant combination exhibited a statistically significant higher revision rate (1.75/100 component years) (p < 0.001). In the < 40 group, revision rate for the hybrid implant combination (0.46/100 component years) was significantly lower than the uncemented implant combination (1.54/100 component years).

CONCLUSION

The most commonly used hybrid and uncemented implant combinations provided equivalent survival and functional outcomes in patients aged 40-55 years. More research is required to guide implant selection in patients aged < 40 years. The authors suggest a transition away from comparing classes of implants (cemented, uncemented, hybrid) given the diverse product range within these categories.

Lower revision rates for cemented fixation in a long-term survival analysis of three different LCS designs

BACKGROUND

In primary Total Knee Arthroplasty (TKA), it is still not clear if cemented or uncemented fixation has the best long-term survival. The Low Contact Stress (LCS) mobile-bearing (MB) knee system was introduced in 1977. The aim of this study is to investigate the long-term survival of this design with a minimum of 15-year follow-up.

METHODS

A retrospective analysis was performed, with the primary endpoint for survival defined as revision. Cox regression analysis was performed to assess the association between type of fixation and the risk of revision, while correcting for potential confounders (diagnosis, design, age and sex).

RESULTS

1271 cases were included with inflammatory joint disease (IJD) (657 cases) and non-IJD (614 cases). TKAs were performed cemented in 522 cases and uncemented in 749 cases. A bicruciate retaining design was used in 180 cases, a rotating platform design in 174 cases and an anterior posterior glide posterior cruciate-retaining (PCR) design in 916 cases. Cumulative incidence of component revision at 15 years was 2.7% (95% CI 1.6; 4.5) for cemented and 10% (95% CI 8.1; 12.4) for uncemented TKA, respectively. The 20-year cumulative incidence was 2.9% (95% CI 1.7; 4.7) for cemented and 10.9% (95% CI 8.8; 13.4) for uncemented TKA, respectively. Age, non-IJD and PCR design were associated with a significantly higher risk of revision, regardless of the type of fixation.

CONCLUSION

Long-term survival for patients undergoing cemented or uncemented TKA using the LCS MB system revealed lower revision rates for cemented fixation. Revision risk was higher in younger, non-IJD patients who had the PCR design, regardless of the type of fixation. For the LCS MB TKA design, it is recommended to use cemented fixation.

Mortality associated with cemented and uncemented fixation of hemiarthroplasty and total hip replacement in the surgical management of intracapsular hip fractures: A systematic review and meta-analysis

BACKGROUND

The use of bone cement for implant fixation in the surgical management of intracapsular hip fractures (IHFs) remains controversial. Although UK national guidance supports cementation, many surgeons remain cautious of its use. In this systematic review and meta-analysis, we aimed to evaluate evidence surrounding post-operative mortality associated with cemented and uncemented total hip replacement and hemiarthroplasty implants.

METHODS

We conducted a search of MEDLINE and Embase databases for randomised controlled trials (RCTs) from commencement until 17 June 2020. Articles reporting mortality or patient survival as an outcome following total hip replacement (THR) or hemiarthroplasty (HA) to manage IHFs were included. Articles not comparing cemented and uncemented fixation were excluded. A meta-analysis on mortality stratified by post-operative follow-up period was conducted using a fixed-effects model. The Revised Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias.

RESULTS

Our initial search found 77 references, 13 of which were eligible for full-text review. Mortality data from 12 studies were pooled and included in the meta-analysis. 1 599 operations were reported: 882 involved cemented fixation; 717, uncemented. Mortality outcome reporting ranged from less than 7 days to 5 years post-operation. No significant difference was observed between the two groups in mortality at any follow-up period. Study quality assessment revealed low certainty in mortality estimates.

CONCLUSION

Existing evidence indicates that cementation has no effect on mortality at any reported follow-up time period. Even with the use of evidence synthesis, the sample size remains relatively low for mortality outcomes and insufficiently powered to reliably determine differences between groups.

Comparison of functional outcomes and complications of cemented vs uncemented total hip arthroplasty in the elderly neck of femur fracture patients: A systematic review and meta-analysis

PURPOSE

The neck of femur fractures in the elderly is a global concern. These fractures impair the quality of living and add to morbidity and mortality. A Multitude of treatment options for the same. This systematic review focuses on evaluating outcomes between cemented and uncemented total hip replacement in the elderly population with neck of femur fractures.

MATERIAL AND METHODS

The search was conducted in databases PubMed, Embase, Scopus, open grey, and Cochrane following PRISMA guidelines. The studies fulfilling the inclusion criteria were included, scrutinized for data analysis, and also quality appraisal of all the included studies was conducted to be included in this article.

RESULTS

A total of 7 studies were included (2 RCT, 5 retrospective studies) comprising 1171 THRs. Data analysis showed a higher HHS in cemented compared to uncemented(p < 0.001). The uncemented group had a significantly higher rate of revision, dislocation, and periprosthetic fracture compared to cemented group(p < 0.001). However, VAS score, loosening rates, and heterotopic ossification were similar in both statistically insignificant groups.

CONCLUSION

Choosing between cemented and uncemented techniques had been a controversy with lesser data due to higher morbidity and mortality. This systematic review provides information regarding functional outcomes and complications in both groups. The cemented group had better outcomes and lesser complications which should be preferred in elderly patients as the conclusion of this study. However, a larger RCT with better follow-up is still required.

LEVEL OF EVIDENCE

Level I, systematic review and meta-analysis.

Patella Strength Characteristics in Cemented vs Press-fit Implants: A Biomechanical Analysis of Initial Stability

Background

Patellar resurfacing is routinely performed during total knee arthroplasty to reduce pain associated with patellofemoral osteoarthritis. With 3-dimensional ingrowth materials readily available, the present study aimed to evaluate if cemented polyethylene (CP) patellar buttons conferred higher ultimate load to failure than press-fit metal-backed (PF) buttons in axial compression.

Material and methods

Ten matched cadaveric and 20 composite patellae were resurfaced and implanted with either a PF or CP button. Biomechanical testing using an MTS machine was performed to measure the force required to generate a periprosthetic patella fracture. Mean load to failure and load to failure per 1-mm patellar thickness were compared with a paired and independent samples Students’ t-test for the cadaveric and composite patellae, respectively.

Results

The average load to failure for the matched cadaveric patellae with PF implants was significantly lower than that for patellae with CP buttons (4082.05 N vs 5898.37 N, P = .045). The average load to failure for composite patella with PF implants was significantly higher than that for composite patellae with CP implants (6004.09 N vs 4551.40 N, P = .001). The mean load to failure per 1-mm patellar thickness was also significantly higher for composite patellae with PF implants (263.80 N/mm vs 200.37 N/mm, P = .001).

Conclusion

Cadaveric patellae with cemented implants had a significantly higher ultimate load to failure in axial compression than press-fit patella. However, this result was reversed in the composite model. Exploration of biological and composite model properties could provide further insight into patellar implant selection during total knee arthroplasty.

Long-term outcomes were similar between hybrid and cemented TKAs performed on paired knees at a minimum 15 years of follow-up

PURPOSE

To compare long-term clinical and radiographic results and survival rates between hybrid and cemented total knee arthroplasties (TKAs) performed on paired knees.

METHODS

Seventy-two patients with hybrid and cemented TKAs performed on paired knees with NexGen® cruciate-retaining prostheses were retrospectively reviewed after a minimum 15 years of follow-up. Mean follow-up period was 17.5 years. Preoperative alignment deformity and range of motion (ROM) were not different between groups. The Knee Society score, Western Ontario and McMaster Universities Osteoarthritis Index, and ROM were evaluated. Radiographically, change in joint space width, component loosening, and osteolysis were evaluated. Implant survival rate was analyzed.

RESULTS

There were no significant differences in clinical results between hybrid and cemented TKAs performed on paired knees of 72 patients at the last follow-up. No significant difference was observed in the change in joint space width between the two groups at the last follow-up (medial = 0.3 mm vs. 0.4 mm; lateral = 0.1 mm vs. 0.2 mm). One hybrid TKA showed tibial component loosening, for which revision was performed. There was femoral osteolysis in one hybrid and one cemented TKA, and tibial osteolysis in eight hybrid TKAs and seven cemented TKAs (n.s., respectively). The 20-year survival rate was 97.7% for hybrid TKAs and 100% for cemented TKAs (n.s.).

CONCLUSION

The long-term outcomes were similar between hybrid and cemented TKAs performed on paired knees at a minimum 15 years of follow-up. The method of femoral component fixation did not have a significant effect on long-term TKA success.

LEVEL OF EVIDENCE

III.

Should patient age thresholds dictate fixation strategy in total hip arthroplasty?

AIMS

Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost.

METHODS

In a high-volume, tertiary referral centre, we identified 10,112 THAs from a prospectively collected database, including 1,699 cemented THAs, 5,782 hybrid THAs, and 2,631 cementless THAs. The endpoint was revision for any reason. Secondary analysis included examination of implant survivorship in patients aged over 70 years, over 75 years, and over 80 years at primary THA.

RESULTS

Cemented fixation had the lowest implant survival in all age groups, with a total ten-year survivorship of 97.0% (95% confidence interval (CI) 95.8 to 97.8) in the cemented group, 97.6% (95% CI 96.9 to 98.1) in the hybrid group, and 97.9% (95% CI 96.9 to 98.6) in the cementless group. This was not statistically significant (p = 0.092). There was no age group where cemented fixation outperformed hybrid or cementless fixation.

CONCLUSION

While all fixation techniques performed well at long-term follow-up, cemented fixation was associated with the lowest implant survival in all age groups, including in more elderly patients. We recommend that surgeons should carefully monitor their own outcomes and use fixation techniques that they are familiar with, and deliver the best outcomes in their own hands. Cite this article: Bone Joint J 2022;104-B(2):206-211.

Cemented or uncemented stem?

OBJECTIVE

The purposes of this study were to compare functional outcomes, radiographic stem changes and complication rate in patients with proximal humeral fractures operated with cemented or uncemented RSA.

METHODS

Retrospective review of 68 primary RSAs in PHF, 45 cemented/23 uncemented. Functional outcomes were evaluated according to constant, ASES scales and the range of motion (ROM). Radiographic assessment was performed at a minimum of two years post-operatively.

RESULTS

The mean follow-up cemented/uncemented was 37.8/26.5 months (p = .04) and the mean age 78/80 years old (p = .09). The functional outcome and range of movement were equivalent in the two groups except for the forward flexion that was significantly higher in the cemented group (p = .03). Stress shielding was seen in 30.4% of uncemented group and none in the cemented. Anatomic tuberosity healing was significantly higher with uncemented components compared with cemented components (64% vs 91%, p = .02). Cemented stems had radiolucent lines with a width of 2 mm or more in three or more Gruen zones in 9% vs 0% in the uncemented group and an evident change in the stem position was present in 4% vs 0% in the non-cemented group.

CONCLUSION

At mid-term follow-up, no differences in functional outcomes were detected depending on the stem fixation technique. Cemented stems, however, have a complication rate (including stem loosening) significantly higher than press-fit stems.

The impact of stem fixation method on Vancouver Type B1 periprosthetic femoral fracture management

INTRODUCTION

Our understanding of the impact of the stem fixation method in total hip arthroplasty (THA) on the subsequent management of periprosthetic femoral fractures (PFF) is still limited. This study aimed to investigate and quantify the effect of the stem fixation method, i.e., cemented vs. uncemented THA, on the management of Vancouver Type B1 periprosthetic femoral fractures with the same plate.

METHODS

Eight laboratory models of synthetic femora were divided into two groups and implanted with either a cemented or uncemented hip prosthesis. The overall stiffness and strain distribution were measured under an anatomical one-legged stance. All eight specimens underwent an osteotomy to simulate Vancouver type B1 PFF's. Fractures were then fixed using the same extramedullary plate and screws. The same measurements and fracture movement were taken under the same loading conditions.

RESULTS

Highlighted that the uncemented THA and PFF fixation constructs had a lower overall stiffness. Subsequently, the mechanical strain on the fracture plate for the uncemented construct was higher compared to the cemented constructs.

CONCLUSION

PFF fixation of a Vancouver type B1 fracture using a plate may have a higher risk of failure in uncemented THAs.

Incidence of Radiolucent Lines after Cemented Total Knee Arthroplasty

BACKGROUND

Cemented Total Knee Arthroplasty (TKA) provides excellent long-term survival rates and functional results, however, radiolucent lines (RLLs) often appear during early post-operative follow-up and their incidence and clinical significance are unknown. The primary aim was to establish the incidence, location, frequency, and time taken for RLLs to appear within the first year after a primary cemented TKA with an anatomic tibial baseplate (Smith and Nephew, LEGION Total Knee System).

METHODS

This was a retrospective analysis of 135 primary cemented TKA in 131 patients over three years. We compared demographics, serial radiographs, and early clinical and functional outcomes.

RESULTS

There were 65 TKAs (48%) in 62 patients who had RLLs within the first year post-operatively. Most were females (58.8%). Mean age was 68.3 ± 7.9 years. There were 88 RLLs, with the most and second commonest location at the medial tibial baseplate (38%) and anterior femoral flange (23%). 89% were in the bone-cement interface. The largest average length of RLLs were at the anterior flange of the femoral component (1.98 ± 1.33 mm). The average time to development was 6.5 ± 4.1 months. None of these patients had infections nor required revision. Patients with RLLs did not do worse in functional and clinical scoring at 1-year.

CONCLUSION

There was a 48% incidence of physiological RLLs after cemented TKA, with the highest occurrence at the medial tibial baseplate at 38%. These radiolucent lines did not affect early post-operative clinical and functional outcomes of patients.

The use of mobile bearing TKA in valgus deformities - A clinical study

BACKGROUND

The number of patients presenting valgus deformities undergoing total knee arthroplasty (TKA) represents approximately 10% of the total number of TKAs performed: the presence of valgus deformity requires the implant to have proper alignment, stability and balance to achieve successful clinical outcomes, especially for knees with high coronal deformities, but these have proven to be difficult goals to achieve and therefore the use of constrained prostheses is often recommended for these cases. However, even though the use of unconstrained mobile bearing for severe knee deformities is rare, it has been shown to give successful outcomes and therefore the aim of this study is to evaluate whether this surgical technique can achieve satisfactory clinical results and correct alignment, as well as good patient satisfaction.

METHODS

This study presents the results of 69 TKA performed with cemented mobile bearing implants by a single surgeon on knee affected by valgus deformities. Asymmetric inserts were adopted for all the implants and an alignment surgical tool, dedicated for valgus patients, was used during the operation. Angles of valgus, WOMAC surveys and Numeric Rating Scale for pain were recorded to evaluate the results of the operations.

RESULTS

A total of 67 pre-op WOMAC questionnaire surveys were collected, with the mean result of this evaluation being 15.9 points. The Numeric Rating Scale for pain had an average of 2.2 for 68 tests. The deformities were corrected from a mean total preoperative valgus angle of 12.5° to a postoperative valgus deformity average of 0.6°. During follow-up, only one patient had serious complications due to the rupture of the extensor apparatus following a domestic accident involving falling. Further 10 patients have mild complications related to injuries such as pain of varying intensity, burning, or swelling of the knee. The level of satisfaction from 0 to 10 (0 not at all satisfied and 10 perfectly satisfied) had an average score of 7.7.

CONCLUSIONS

The surgical approach presented, involving a less constrained model if compared to the ones usually chosen, allowed to achieve correct alignment and high patient satisfaction using mobile bearing implants on valgus knee deformities; further patient follow-up will be performed to evaluate long-term outcomes, but the results achieved already represent a significative finding.

Biomechanical analysis of femoral stems in hinged total knee arthroplasty in physiological and osteoporotic bone

BACKGROUND AND OBJECTIVE

Adequate fixation is a requisite for hinged Total Knee Arthroplasty (TKA): consequently, several stem solutions are currently available. However, there are no evidence-based biomechanical guidelines for surgeons to determine the appropriate stem length and whether to use cemented or press-fit fixation. The objective of this study is therefore to compare, using a validated finite-element model, bone stresses and implant micromotions in different configurations.

METHODS

The 3D bone geometries were obtained from CT-scans reconstruction and the 3D model components of an Endo-Model Rotating Hinge (WALDEMAR LINK GmbH & Co. KG, Hamburg, Germany) were generated from industrial designs provided by the manufacturer. Sixteen configurations were investigated considering four stem lengths (50, 95, 120, 160 mm), cemented and press-fit fixation and physiological and osteoporotic bone properties. A further configuration without stem was analyzed as control. Average Von-Mises stresses, risk of fracture and micromotions were extracted in several regions of interest at 0° and 90° of flexion, under physiological load conditions.

RESULTS

Generally, longer stems guarantee better fixation compared to short ones; however, they induce higher stress-shielding effect in the distal region of the femur (even greater for press-fit stems, with values up to 38.5% greater than cemented ones). The cemented configurations, especially in case of 50 mm and 95 mm lengths, induce lower micromotions (down to 16% lower) compared to their respective press-fit configurations. The osteoporotic RF values were greater than the physiological ones (up to 20.5%), but always below the bone limit of fracture.

CONCLUSIONS

According to this study, when surgeons need to select a femoral stem in a hinged TKA aiming to proper stability and bone stress, the preferable option would be short cemented stems.

Cementless unicompartmental knee arthroplasty results in higher pain levels compared to the cemented technique: a prospective register study

PURPOSE

In recent years, the preferred fixation method for unicompartmental knee arthroplasty (UKA) has changed from cemented to cementless. The aim of this study was to compare patient-reported outcome measures (PROMs) from the cemented versus cementless techniques two- and twelve-months post-operation.

METHODS

From 2015 to 2019, 187 cemented and 261 cementless UKAs were included based on an institutional registry. The Oxford Unicompartmental Knee System™ (Zimmer Biomet, Bridgend, United Kingdom) was used for all patients. Three experienced surgeons performed all procedures. Data were collected pre- and peroperatively, and at two- and twelve-months postoperatively. PROMs included pain (evaluated on a numeric rating scale [NRS] during activity and at rest), and knee function (evaluated with the disease-specific short form of the Knee injury and Osteoarthritis Outcome Score [KOOS-PS]). Patients also rated postoperative joint function (better, unchanged, uncertain or worse) and were asked, "based on your experience to date, would you go through the surgery again?". Duration of surgery was noted and revisions during the first post-operative year were evaluated.

RESULTS

The cemented group reported significantly lower activity-related pain at both two- and twelve-month follow-up. This was also the case for pain at rest at twelve-month follow-up, and KOOS-PS at two-month follow-up. Duration of surgery (adjusted for surgeon differences) was eight minutes less on average with the cementless technique. Eleven prosthetic joint infections (PJIs) were found following the cementless fixation technique compared to three using the cemented implant.

CONCLUSION

UKA cases with cemented implants had lower pain scores during activity two and twelve months after surgery compared with those who had cementless implants. Differences in favor of the cemented group were also found for pain at rest one year after surgery and for KOOS-PS two months after. Surgery was significantly shorter in duration in the cementless group, but a relatively high number of PJIs were found in that same group.

LEVEL OF EVIDENCE

Level II.

Comparison of five-year clinical outcomes of 524 cemented and cementless medial unicompartmental knee replacements

AIM

To compare the outcomes of cemented and cementless Unicompartmental Knee Replacements (UKR) at 5 years after surgery.

METHODS

262 cemented and 262 cementless medial mobile-bearing UKR, implanted by four high-volume surgeons using identical indications and surgical techniques, were reviewed by independent physiotherapists at 5 years. Survival, Oxford Knee Score (OKS), American Knee Society Score (AKSS), and EQ-5D-5L were assessed. The cementless cohort was mainly implanted after the cemented. Each cohort was divided into early and late sub-groups and compared, to assess if any differences were due to progressive improvement in surgical practice over time.

RESULTS

There were no significant differences between the cohorts for demographics, pre-operative scores, and 5-year revision (0.8%), re-operation (1.5%), and complication rates (5%). The cementless cohort had significantly better 5-year OKS (43v41, p = 0.008), AKSS-Objective (94v90, p = 0.049) and EQ-5D-5L (0.81v0.87, p = 0.0001). Pain sub-scores within OKS, AKSS, and EQ-5D-5L were also significantly better in the cementless cohort, and the differences were proportionally much greater and more significant than differences in their respective overall scores. There was no significant improvement in scores between the early and late subgroups of the cohorts, whereas the 'early-cementless' cohort had significantly better scores than the contemporaneously implanted 'late-cemented' cohort. This suggests that differences found were due to implant type, instead of improved surgical practice over time.

CONCLUSION

Cementless UKR is associated with better clinical outcomes than cemented UKR, which is primarily due to improved pain relief. Both cemented and cementless UKR are safe with low reoperation and complication rates, and a 5-year survival of 99%.

The effect of cemented acetabular component geometry on the risk of revision for instability or loosening : a study of 224,874 primary hip arthroplasties from the National Joint Registry

AIMS

To determine if primary cemented acetabular component geometry (long posterior wall (LPW), hooded, or offset reorientating) influences the risk of revision total hip arthroplasty (THA) for instability or loosening.

METHODS

The National Joint Registry (NJR) dataset was analyzed for primary THAs performed between 2003 and 2017. A cohort of 224,874 cemented acetabular components were included. The effect of acetabular component geometry on the risk of revision for instability or for loosening was investigated using log-binomial regression adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, operating surgeon grade, surgical approach, polyethylene crosslinking, and prosthetic head size. A competing risk survival analysis was performed with the competing risks being revision for other indications or death.

RESULTS

The distribution of acetabular component geometries was: LPW 81.2%; hooded 18.7%; and offset reorientating 0.1%. There were 3,313 (1.5%) revision THAs performed, of which 815 (0.4%) were for instability and 838 (0.4%) were for loosening. Compared to the LPW group, the adjusted subhazard ratio of revision for instability in the hooded group was 2.31 (p < 0.001) and 4.12 (p = 0.047) in the offset reorientating group. Likewise, the subhazard ratio of revision for loosening was 2.65 (p < 0.001) in the hooded group and 13.61 (p < 0.001) in the offset reorientating group. A time-varying subhazard ratio of revision for instability (hooded vs LPW) was found, being greatest within the first three months.

CONCLUSION

This registry-based study confirms a significantly higher risk of revision after cemented THA for instability and for loosening when a hooded or offset reorientating acetabular component is used, compared to a LPW component. Further research is required to clarify if certain patients benefit from the use of hooded or offset reorientating components, but we recommend caution when using such components in routine clinical practice. Cite this article: Bone Joint J 2021;103-B(11):1669-1677.

Reduction of Periprosthetic Proximal Femur Fracture in Direct Anterior Total Hip According to Stem Design

The direct anterior approach (DAA) is gaining popularity in primary total hip arthroplasty (THA). Although DAA has demonstrated many advantages over other surgical approaches, periprosthetic femur fractures (PPFF) rates continue to be higher. Femoral stem designs that allow for easier insertion via a DAA may contribute to the higher rates of fracture seen in this approach. Certain stem designs and fixation methods may reduce the risk of PPFF via a DAA in primary THA.

Outcomes of revision total hip arthroplasty using a vascularised anterior femoral window

PURPOSE

Extraction of the distal femoral cement mantle and restrictor during revision total hip arthroplasty (rTHA) is challenging and can compromise host bone stock. The aim of this study is to report outcomes of our femoral windowing technique for cement removal.

METHODS

We report on a cohort of 36 patients with an average age of 68.7 years who underwent 40 cemented rTHA between 2011 and 2017 using a vascularised anterior femoral window. Clinical and radiological outcomes were retrospectively reviewed with a mean follow-up of 6.6 years (range, 3.8-10).

RESULTS

Latest mean WOMAC score was 25.4 and all windows achieved radiographic union by a mean of 7.9 weeks. Femoral component survivorship was 100% and 38 out of 40 rTHAs showed no evidence of radiological loosening.

CONCLUSION

The vascularised anterior window to remove the distal femoral cement mantle under direct vision is safe and reproducible with excellent clinical and radiographic results.

Risk of revision for medial unicompartmental knee arthroplasty according to fixation and bearing type : short- to mid-term results from the Dutch Arthroplasty Register

AIMS

Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs.

METHODS

A total of 21,610 medial UKAs from 2007 to 2018 were selected from the Dutch Arthroplasty Register. Multivariate Cox regression analyses were used to compare uncemented mobile bearings with cemented mobile and fixed bearings. Adjustments were made for patient and surgical factors, with their interactions being considered. Reasons and type of revision in the first two years after surgery were assessed.

RESULTS

In hospitals performing less than 100 cases per year, cemented mobile bearings reported comparable adjusted risks of revision as uncemented mobile bearings. However, in hospitals performing more than 100 cases per year, the adjusted risk of revision was higher for cemented mobile bearings compared to uncemented mobile bearings (hazard ratio 1.78 (95% confidence interval 1.34 to 2.35)). The adjusted risk of revision between cemented fixed bearing and uncemented mobile bearing was comparable, independent of annual hospital volume. In addition, 12.3% of uncemented mobile bearing, 20.3% of cemented mobile bearing, and 41.5% of uncemented fixed bearing revisions were for tibial component loosening. The figures for instability were 23.6%, 14.5% and 11.7%, respectively, and for periprosthetic fractures were 10.0%, 2.8%, and 3.5%. Bearing exchange was the type of revision in 40% of uncemented mobile bearing, 24.3% of cemented mobile bearing, and 5.3% cemented fixed bearing revisions.

CONCLUSION

The findings of this study demonstrated improved survival with use of uncemented compared to cemented mobile bearings in medial UKA, only in those hospitals performing more than 100 cases per year. Cemented fixed bearings reported comparable survival results as uncemented mobile bearings, regardless of the annual hospital volume. The high rates of instability, periprosthetic fractures, and bearing exchange in uncemented mobile bearings emphasize the need for further research. Cite this article: Bone Joint J 2021;103-B(7):1261-1269.

Pain associated with cemented and uncemented long-stemmed tibial components in revision total knee arthroplasty

AIMS

Stemmed tibial components are frequently used in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate patient satisfaction, overall pain, and diaphyseal tibial pain in patients who underwent revision TKA with cemented or uncemented stemmed tibial components.

METHODS

This is a retrospective cohort study involving 110 patients with revision TKA with cemented versus uncemented stemmed tibial components. Patients who underwent revision TKA with stemmed tibial components over a 15-year period at a single institution with at least two-year follow-up were assessed. Pain was evaluated through postal surveys. There were 63 patients with cemented tibial stems and 47 with uncemented stems. Radiographs and Knee Society Scores were used to evaluate for objective findings associated with pain or patient dissatisfaction. Postal surveys were analyzed using Fisher's exact test and the independent-samples t-test. Logistic regression was used to adjust for age, sex, and preoperative bone loss.

RESULTS

No statistically significant differences in stem length, operative side, or indications for revision were found between the two cohorts. Tibial pain at the end of the stem was present in 25.3% (16/63) of cemented stems and 25.5% (12/47) of uncemented stems (p = 1.000); 74.6% (47/63) of cemented patients and 78.7% (37/47) of uncemented patients were satisfied following revision TKA (p = 0.657).

CONCLUSION

There were no differences in patient satisfaction, overall pain, and diaphyseal tibial pain in cemented and uncemented stemmed tibial components in revision TKA. Patient factors, rather than implant selection and surgical technique, likely play a large role in the presence of postoperative pain. Stemmed tibial components have been shown to be a possible source of pain in revision TKA. There is no difference in patient satisfaction or postoperative pain with cemented or uncemented stemmed tibial components in revision TKA. Cite this article: Bone Joint J 2021;103-B(6 Supple A):165-170.

Cemented versus uncemented hemiarthroplasty for the management of femoral neck fractures in the elderly: a meta-analysis and systematic review

INTRODUCTION

Hemiarthroplasty is commonly used to treat unstable femoral neck fractures in older patients. However, there is no consensus on the use of cement during hemiarthroplasty. Therefore, we performed a systematic review to focus on the outcomes of cemented and uncemented hemiarthroplasty for the treatment of femoral neck fractures in older patients.

MATERIALS AND METHODS

Pubmed, Cochrane Central Register of Controlled Trials, and Ovid were searched for studies related comparison of cemented versus uncemented hemiarthroplasty for unstable femoral neck fractures from inception to Jan 20, 2020. The quality of the included randomized controlled trials (RCTs) was assessed using the Cochrane Collaboration tool. The meta-analysis was performed using the RevMan 5.2 software.

RESULTS

Eleven RCTs were included in the meta-analysis. Cemented hemiarthroplasty was found to be superior to uncemented arthroplasty with respect to reoperation rate (RR 0.6, 95% CI 0.38-0.96, p = 0.03), complications related to prosthesis (RR 0.39, 95% CI 0.23-0.68, p = 0.0008), residual pain (RR 0.66, 95% CI 0.52-0.83, p = 0.0004), and operation time (MD 8.22, 95% CI 6.30-10.14, p < 0.00001). There were no significant between-group differences with respect to local and general complications, duration of hospital stay, hip function, and mortality.

CONCLUSIONS

This meta-analysis showed cemented hemiarthroplasty might be an optimum choice for treating unstable femoral neck fractures in older patients. However, the results of this meta-analysis should be interpreted cautiously owing to some limitations. Further studies are required to provide more robust evidence.

Lower early revision rates after uncemented Oxford Unicompartmental Knee Arthroplasty (UKA) than cemented Oxford UKA: A meta-analysis

BACKGROUND

UKA has been proved to offer good results in treating patients with unicompartmental knee osteoarthritis (OA). However, there is still a controversy about the better fixation mode in UKA procedure between cemented and uncemented prosthesis. Therefore, this meta-analysis was conducted to compare clinical and radiological outcomes of cemented versus uncemented Oxford UKA.

HYPOTHESIS

The study surmised that uncemented Oxford UKA was associated with shorter operation time, higher function scores, lower revision rate and less radiolucency than cemented Oxford UKA.

METHODS

A meta-analysis to compare postoperative outcomes between cemented and uncemented Oxford UKA wsa conducted. The primary outcomes included Oxford knee score (OKS), revision rate, and incidence of radiolucency. The secondary outcomes included operation time, knee society score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), range of motion (ROM). PubMed, Embase, Web of Science, the Cochrane Library and China national knowledge infrastructure were searched until April, 2020 to identify studies for including. Relevant data were analyzed using RevMan v5.3.

RESULTS

We identified nine studies involving 901 patients meeting our inclusion criteria. No significant difference of OKS was found in both groups. Compared with cemented group, uncemented Oxford UKA group was associated with lower revision rate (95% CI: 0.90 to 3.73; OR=1.83) and less radiolucent lines (95% CI: 0.79 to 9.52; OR=2.75) after following up for at least 2years. The operation time was significantly shorter by 10.12minutes (95% CI: p<0.00001) in the uncemented group when compared against the cemented group. The KSS, WOMAC, ROM were not significantly different between two groups.

CONCLUSIONS

Uncemented Oxford UKA had lower revision rate, shorter operation time and less radiolucent lines than cemented Oxford UKA did. There is still need for more long follow-up clinical trials with high evidence level to determine which method of fixation is of preferable for Oxford UKA in the future.

LEVEL OF EVIDENCE

I.

Risk factors for a radiolucent line around the acetabular component with an interface bioactive bone cement technique after primary cemented total hip arthroplasty

Aims

The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA.

Methods

A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis.

Results

RLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7).

Conclusion

This study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL.

Cite this article: Bone Joint Open 2021;2(5):278–292.

Uncemented total hip arthroplasty can be used safely in the elderly population

Aims

“Get It Right First Time” (GIRFT) and NHS England’s Best Practice Tariff (BPT) have published directives advising that patients over the ages of 65 (GIRFT) and 69 years (BPT) receiving total hip arthroplasty (THA) should receive cemented implants and have brought in financial penalties if this policy is not observed. Despite this, worldwide, uncemented component use has increased, a situation described as a ‘paradox’. GIRFT and BPT do, however, acknowledge more data are required to support this edict with current policies based on the National Joint Registry survivorship and implant costs.

Methods

This study compares THA outcomes for over 1,000 uncemented Corail/Pinnacle constructs used in all age groups/patient frailty, under one surgeon, with identical pre- and postoperative pathways over a nine-year period with mean follow-up of five years and two months (range: nine months to nine years and nine months). Implant information, survivorship, and regular postoperative Oxford Hip Scores (OHS) were collected and two comparisons undertaken: a comparison of those aged over 65 years with those 65 and under and a second comparison of those aged 70 years and over with those aged under 70.

Results

Overall revision rate was 1.3% (13/1,004). A greater number of revisions were undertaken in those aged over 65 years, but numbers were small and did not reach significance. The majority of revisions were implant-independent. Single component analysis revealed a 99.9% and 99.6% survival for the uncemented cup and femoral component, respectively. Mean patient-reported outcome measures (PROMs) improvement for all ages outperformed the national PROMs and a significantly greater proportion of those aged over 65/69 years reached and maintained a meaningful improvement in their OHS earlier than their younger counterparts (p < 0.05/0.01 respectively).

Conclusion

This study confirms that this uncemented THA system can be used safely and effectively in patient groups aged over 65 years and those over 69 years, with low complication and revision rates.

Cite this article: Bone Jt Open 2021;2(5):293–300.

Uncemented total hip arthroplasty; increased risk of early periprosthetic fracture requiring revision surgery in elderly females

Purpose

The preferred method of stem fixation in total hip arthroplasty (THA) remains debatable. Uncemented THA favors a lower rate of aseptic loosening but has an increased risk of early periprosthetic fractures (EPF). We hypothesize that routine placement of uncemented THA by experienced surgeons diminishes this EPF-risk. The purpose of this study is to investigate the effect of age, gender, ASA classification and BMI of THA performed by experienced surgeons on the risk of EPF.

Methods

A retrospective cohort study including all primary THAs and revision surgeries performed between 2012 and 2018. Possible predictive factors included are age, gender, BMI, ASA classification, presence of osteoporosis, Dorr classification, revision surgery type and clinical outcome. A number needed to treat (NNT) analysis was conducted assuming that cementing THA prevents EPF.

Results

2635 primary THAs were performed. Indications for 70 revisions included 18 EPF in uncemented THA female patients. Periprosthetic fractures without a relevant trauma occurred within six weeks in 16 patients. There was a statistically significant correlation between EPF-risk and age (P = 0.032), female gender (P = 0.001) and ASA classification (P = 0.015). For age ≥75, there was an increase in EPF (P = 0.047). With the assumption that cementing would prevent EPF, the NNT is 48. No statistically significant correlation was found between EPF and BMI, osteoporosis or Dorr classification.

Conclusion

Female patients aged ≥75 have an increased EPF-risk after uncemented THA and would therefore benefit from treatment with a cemented stem. An ASA score of III-IV is an independent risk factor for EPF after uncemented THA.

Impact of surgical alignment, tray material, PCL condition, and patient anatomy on tibial strains after TKA

Bone remodeling after total knee arthroplasty is regulated by the changes in strain energy density (SED), however, the critical parameters influencing post-operative SED distributions are not fully understood. This study aimed to investigate the impact of surgical alignment, tray material properties, posterior cruciate ligament (PCL) balance, tray posterior slope, and patient anatomy on SED distributions in the proximal tibia. Finite element models of two tibiae (different anatomy) with configurations of two implant materials, two surgical alignments, two posterior slopes, and two PCL conditions were developed. The models were tested under the peak loading conditions during gait, deep knee bending, and stair descent. For each configuration, the contact forces and locations and soft-tissue loads of interest were taken into consideration. SED in the proximal tibia was predicted and the changes in strain distributions were compared for each of the factors studied. Tibial anatomy had the most impact on the proximal bone SED distributions, followed by PCL balancing, surgical alignment, and posterior slope. In addition, the thickness of the remaining cortical wall after implantation was also a significant consideration when evaluating tibial anatomy. The resulting SED changes for alignment, posterior slope, and PCL factors were mainly due to the differences in joint and soft-tissue loading conditions. A lower modulus tray material did result in changes in the post-operative strain state, however, these were almost negligible compared to that seen for the other factors.

Minimum 5 year follow-up of clinical and radiographic results of cemented acetabular components with an interface bioactive bone cement technique in primary cemented total hip arthroplasty

INTRODUCTION

A well-fixed cement-bone interface is a crucial factor for acetabular and femoral components in cemented total hip arthroplasty (THA). The aim of the present study was to evaluate the middle-term clinical and radiological results of fixing the acetabular component with an interface bioactive bone cement (IBBC) technique in primary cemented THA.

MATERIALS AND METHODS

We undertook a retrospective review was undertaken of 193 primary cemented THAs in 174 patients using acetabular components cemented with an IBBC technique and followed for a minimum of 5 years (mean 8.3 years; range 5-17 years). Baseline data, clinical and radiological outcomes were evaluated.

RESULTS

Japanese Orthopedic Association hip score and modified Harris hip scores demonstrated significant clinical improvement in all patients (p < 0.001). Radiolucent lines were detected in 15 hips (7.8%) at the first year and 24 hips (12.4%) at the final post-operative follow-up. The Kaplan-Meier survivorship with radiographic loosening as the end point was 97.8% [95% confidence interval (CI) 95.2-100]. With revision of the acetabular component for aseptic loosening as the end point, component survival was 99.0% (95% CI 97.5-100). With revision of the acetabular component for any reason as the end point, component survival was 97.0% (95% CI 93.9-100).

CONCLUSIONS

Clinical and radiological results of the acetabular component with the IBBC technique in primary cemented THA were excellent.

Favourable clinical outcomes following cemented arthroplasty after metal-on-metal total hip replacement: a retrospective study with a mean follow-up of 10 years

BACKGROUND

Given the unexpected high rate of failure following metal-on-metal total hip replacement (MoM-THR), it is expected that more MoM-THR patients will experience revision. The long-term outcomes regarding the primary MoM-THR revised to cemented THR (CTHR) remain controversial. The purpose of this retrospective review was to evaluate the long-term outcomes of patients who underwent conversion from MoM-THR to CTHR.

METHODS

A total of 220 patients (220 hips) who underwent a conversion of primary MoM-THR to CTHR from March 2006 to October 2016 were retrospectively reviewed. The primary outcomes were the functional outcomes assessed using the Harris hip scores (HHS) and major radiographic outcomes. Follow-ups occurred at 3 months, 6 months, 1 year, 2 years, and then every two years after revision.

RESULTS

Mean follow-up was 10.1 years (5-13 years). Distinct improvements were detected in the mean HHS between the preoperative and last follow-up analysis (62.35[±8.49] vs. 84.70[±14.68], respectively, p < 0.001). The key orthopaedic complication rate was 18.2% (27/148). Seven (4.7%) cases experienced a CTHR failure at a mean of 3.4 (±1.2) years after revision MoM-THR, mostly attributed to recurrent dislocation.

CONCLUSION

CTHR might yield an acceptable functional score and a low rate of the key orthopaedic complications.

Mortality as a competition risk factor in the survival analysis of the results of the type of fixation of the total hip prosthesis in octogenarian patients

INTRODUCTION

Total hip replacement (THR) is challenging in octogenarians due to associated comorbidities and controversy regarding fixation type. We ask whether cemented THR is superior to uncemented THR in patients above the age of 80 years.

MATERIAL AND METHODS

A total of 382 patients (441 hips) aged 80 years or older who underwent THR between 2004 and 2015 were analysed. A cemented THR was implanted in 196 hips (group 1), an uncemented THR with a grit-blasted stem in 121 (group 2), or with a porous-coated stem in 124 (group 3). Patients in group 1 had a higher mean age, more comorbidities and osteoporotic bone. Survival analysis was calculated using cumulative incidence function to account for the competing risk of death.

RESULTS

Medical complications rate was similar. There were 3post-operative fractures: one in group 2 and 2in group 3. Competing risk analysis showed that the cumulative incidence of revision for any cause was 2.3 in group 1, 6.0 in group 2 and 4.1 in group 3 at 10years, and the cumulative incidence of revision for aseptic loosening was 1.2 in group 1, 3.7 in group 2 and 0 in group 3 at the same period.

CONCLUSIONS

THR presents an acceptable number of adverse events for octogenarian patients. Despite uncemented fixation was satisfactory, the higher peri-prosthetic fracture rate worsens results in this group.

Higher rate of complications with uncemented compared to cemented total hip arthroplasty for displaced intracapsular hip fractures: A randomised controlled trial of 50 patients

Background

The primary aim of this study was to compare the functional outcome of uncemented with cemented total hip arthroplasty (THA) for displaced intracapsular hip fractures. The secondary aims were to assess length of surgery, blood loss, complications and revision rate between the two groups.

Methods

A prospective double-blind randomised control trial was conducted. Fifty patients with an intracapsular hip fracture meeting the inclusion criteria were randomised to either an uncemented (n = 25) or cemented (n = 25) THA. There were no differences (p > 0.45) in age, gender, health status or preinjury hip function between the groups. The Oxford hip score (OHS), Harris Hip score (HHS), EuroQol 5-dimensional (EQ5D), timed get up-and-go (TUG), pain and patient satisfaction were used to assess outcome. These were assessed at 4, 12 and 72 months after surgery, apart from the TUG which as only assessed as 6 months.

Results

The study was terminated early due to the significantly (n = 8, p = 0.004) higher rate of intraoperative complications in the uncemented group: three fractures of the proximal femur and five conversions to a cemented acetabular component. There were no significant (p ≥ 0.09) differences in the functional measures (OHS, HSS, EQ5D, TUG and pain) or patient satisfaction between the groups. There was no difference in operative time (p = 0.75) or blood loss (p = 0.66) between the groups. There were two early revisions prior to 3 months post-operatively in the uncemented group and none in the cemented group, but this was not significant (log rank p = 0.16).

Conclusion

There was a high rate of intraoperative complications, which may be due to poor bone quality in this patient group. There were no ergonomic or functional advantages demonstrated between uncemented and cemented THA. Cemented THA should remain as the preferred choice for the treatment of intracapsular hip fractures for patients that meet the criteria for this procedure.

The Effect of Type of Femoral Component Fixation on Mortality and Morbidity after Hip Hemiarthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Hip hemiarthroplasty is a well-established treatment of displaced femoral neck fracture, although debate exists over whether cemented or uncemented fixation is superior. Uncemented prostheses have typically been used in younger, healthier patients and cemented prostheses in older patients with less-stable bone. Also, earlier research has suggested that bone cement has cytotoxic effects and may trigger cardiovascular and respiratory adverse events.

QUESTIONS/PURPOSES

The aim of this systematic review and meta-analysis was to compare morbidity and mortality rates after cemented and uncemented hemiarthroplasty for the treatment of displaced femoral neck fractures in elderly patients.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched seven medical databases for randomized clinical trials and observational studies. We compared cemented and uncemented hemiarthroplasty using the Harris Hip Score (HHS), as well as measures of postoperative pain, mortality, and complications. Data were extracted and pooled as risk ratios or standardized mean difference with their corresponding 95% confidence intervals in a meta-analysis model.

RESULTS

The meta-analysis included 34 studies (12 randomized trials and 22 observational studies), with a total of 42,411 patients. In the pooled estimate, cemented hemiarthroplasty was associated with less risk of postoperative pain than uncemented hemiarthroplasty. There were no significant differences between groups regarding HHS or rates of postoperative mortality, pulmonary embolism, cardiac arrest, myocardial infarction, acute cardiac arrhythmia, or deep venous thrombosis.

CONCLUSIONS

While we found that cemented hemiarthroplasty results in less postoperative pain than uncemented hemiarthroplasty in older patients with femoral neck fracture, the lack of significant differences in functional hip scores, mortality, and complications was surprising. Further high-level research is needed.