The problem total knee replacement: systematic, comprehensive and efficient evaluation

Development of a bespoke finite element wear algorithm to investigate the effect of femoral centre of rotation on the wear evolution in total knee replacements

Total Knee Replacements (TKRs) are a commonly used treatment to help patients suffering from severely damaged knee joints, which is normally brought on by osteoarthritis. The aim of the surgery is to reduce pain and regain function of the joint, however, some of these implants fail prematurely with implant wear being one of the main factors of failure. Computational analysis is an efficient tool that can provide an in-depth insight on the evolution of wear, before utilising experimental techniques which are time-consuming and costly. In this study, a bespoke finite element (FE) based wear algorithm has been further developed for TKRs and was used to investigate how location of femoral centre of rotation (CoR) affects the evolution of wear at the bearing surfaces. Three locations of femoral CoR have been investigated: international standards (ISO) CoR, being the location defined in ISO 14243-3, distal CoR being the centre of the femoral component's distal radius, and reference CoR being the middle ground between the two. All investigations were setup in accordance with ISO 14243-3 for displacement-controlled wear testing conditions for knee simulators. The wear algorithm extracts contact pressure and sliding distance from the FE analysis to determine wear depth, wear pattern, volumetric wear, and wear rates on the polymeric insert and femoral component's bearing surfaces using Archard's wear law. The polymeric insert volumetric wear rate after 5 million cycles (Mc) for ISO, reference, and distal CoR are 4.37mm3/Mc, 5.40mm3/Mc, and 6.83mm3/Mc respectively. Furthermore, the wear pattern's location on the bearing surfaces is dependent on the femoral CoR, with ISO CoR wear pattern being positioned more posteriorly, distal CoR being more anteriorly, and reference CoR in between ISO and distal. The ISO CoR investigation showed a region of minimal wear between two wear regions at the middle of the femoral component's wear pattern, on both medial and lateral condyles. This region of minimal wear reduces for the reference CoR and further reduces for the distal CoR. After 5 Mc, the average polymeric insert-femoral component contact area changes with femoral CoR, with the average contact area being 66.53mm2, 68.35mm2, and 71.21mm2 for ISO, reference, and distal CoRs respectively, with distal having around 7% more contact area than ISO. The results from this study show that there is a wide range of wear values for different locations of femoral CoR. As such the choice of femoral CoR should be carefully considered when performing any wear investigation to ensure that the CoR location is consistent for all studies being compared.

Perioperative Analgesic Interventions for Reduction of Persistent Postsurgical Pain After Total Hip and Knee Arthroplasty: A Systematic Review and Meta-analysis

BACKGROUND

High pain levels immediately after surgery have been associated with persistent postsurgical pain. Still, it is uncertain if analgesic treatment of immediate postsurgical pain prevents the development of persistent postsurgical pain.

METHODS

We searched MEDLINE, CENTRAL, and Embase up to September 12, 2023, for randomized controlled trials investigating perioperative analgesic interventions and with reported pain levels 3 to 24 months after total hip or knee arthroplasty in patients with osteoarthritis. The primary outcome was pain score 3 to 24 months after surgery, assessed at rest and during movement separately. Two authors independently screened, extracted data, and assessed risk of bias using the Cochrane Risk of Bias 2 tool. We conducted meta-analyses and tested their robustness with trial sequential analyses and worst-best and best-worst case analyses.

RESULTS

We included 49 trials with 68 intervention arms. All but 4 trials were at high risk of bias for the primary outcome. Moreover, the included trials were heterogeneous in terms of exclusion criteria, baseline pain severity, and which cointerventions the participants were offered. For pain at rest, no interventions demonstrated a statistically significant difference between intervention and control. For pain during movement, perioperative treatment with duloxetine (7 trials with 641 participants) reduced pain scores at 3 to 24 months after surgery (mean difference -4.9 mm [95% confidence interval {CI}, -6.5 to -3.4] on the 0-100 visual analog scale) compared to placebo. This difference was lower than our predefined threshold for clinical importance of 10 mm.

CONCLUSIONS

We found no perioperative analgesic interventions that reduced pain 3 to 24 months after total hip or knee arthroplasty for osteoarthritis. The literature on perioperative analgesia focused little on potential long-term effects. We encourage the assessment of long-term pain outcomes.

The ROSA robotic-arm system reliably restores joint line height, patella height and posterior condylar offset in total knee arthroplasty

INTRODUCTION

There is growing interest in the use of robotic TKA to improve accuracy of component positioning in Total Knee Arthroplasty (TKA). The aim of this study was to investigate the accuracy of implant component position using the ROSA® knee system with specific reference to Joint Line Height, Patella Height and Posterior Condylar Offset (PCO).

METHODS

This was a retrospective review of a prospectively-maintained database of the initial 100 consecutive TKAs performed by a high volume surgeon using the ROSA® knee system. Both the image-based and imageless workflow were used and two prosthesis types were implanted. To determine the accuracy of component positioning, the immediate post-operative radiograph was reviewed and compared with the immediate pre-operative radiograph with regards to Joint Line Height, Patella Height and Posterior Condylar Offset.

RESULTS

100 consecutive patients undergoing TKA using the ROSA system were included; mean age 70 years (range 49-95 years). Mean change in joint line height was 0.2 mm, patella height (Insall-Salvati ratio) 0.01 and posterior condylar offset 0.02 mm; there was no statistically significant difference between the pre and post-operative values. No difference was demonstrated between image-based or imageless workflows, or between implant design (Persona versus Vanguard) regarding joint line height, patella height and PCO.

CONCLUSION

This study validates the use of the ROSA® knee system in accurately restoring Joint Line Height, Patella Height and Posterior Condylar Offset in TKA surgery. No significant differences were found between imageless and image-based groups, or between implant designs (Persona versus Vanguard).

Alignment and Fixation in Revision Total Knee Arthroplasty With Press-Fit, Offset, Diaphyseal-Engaging Stem Extensions, and Eccentric Reaming Technique

BACKGROUND

A revision total knee arthroplasty must control limb alignment, often to address the cause of failure. Press-fit stems that engage the diaphysis with cement restricted to the metaphysis constitute one fixation technique. These long stems restrict coronal alignment of the prosthesis and as a result reduce the likelihood of extreme malposition. For the same reasons, long stems can make it difficult to manipulate alignment and achieve a specific coronal alignment angle. Nevertheless, femoral stems with a tight diaphyseal fit may still occupy a small range of varus-valgus positions due to the conical distal femoral metaphysis. Pulling the reamer toward the lateral endosteum increases femoral component coronal alignment toward a valgus direction and pushing the reamer medially increases alignment in a more varus direction. A straight stem, in combination with a medially directed reaming, would result in a femoral component that overhangs medially, but an offset stem can recenter the femoral component and maintain the desired alignment. We hypothesized that diaphyseal fit plus this reaming technique can control limb coronal alignment and provide fixation.

METHODS

This was a retrospective clinical and long-leg radiographic study of consecutive revision total knee arthroplasties with minimum 2-year follow-up. Outcomes were correlated with New Zealand Joint Registry data to identify rerevisions of 111 consecutive revision knee arthroplasties, 92 after exclusions, at a minimum 2-year (range, 2 to 10) follow-up.

RESULTS

Mean femoral and tibial canal fill exceeded 91% on antero-posterior and lateral radiographs. The mean hip-knee-ankle angle was 179.6o (174.9-184.0) with 80% within ± 3o of neutral. The hip-ankle axis crossed the central Kennedy zone in 76.5% of cases and the other 24.6% crossed the inner medial and inner lateral zones. Tibial components: 99.0% ± 3o. Femoral components: 89.5% within ± 3o. There were 5 knees that failed due to infection, 3 from femoral loosening, and 1 due to recurvatum instability from polio.

CONCLUSIONS

This study describes a surgical plan and technique for achieving target coronal alignment with press-fit diaphyseal fixation. It is the only series of revision knee arthroplasties with diaphyseal press-fit stems to report canal fill in 2 planes and coronal alignment on full-length radiographs.

Patient-Reported Outcomes and Satisfaction 1 to 3 Years After Revisions of Total Knee Arthroplasties for Unexplained Pain Versus Aseptic Loosening

BACKGROUND

It is unknown if patients are relieved of pain after knee arthroplasty revision for unexplained pain. The aim of this cross-sectional case-control study was to compare patient-reported outcome measures (PROMs) and satisfaction 1 to 3 years after revision of total knee arthroplasties (TKAs) for the indications of unexplained pain versus aseptic loosening.

METHODS

We included 384 patients undergoing TKA revision for the indications of unexplained pain and aseptic loosening from January 1, 2018 to December 31, 2020 from the Danish Knee Arthroplasty Register. A total of 81 patients were revised for unexplained pain and 303 for aseptic loosening. Questionnaires including PROMs (Oxford Knee Score, EQ-5D-5L, and Forgotten Joint Score) and satisfaction with the surgery on a 0-100 scale (100 = not satisfied; 0 = very satisfied) were sent to digitally secured mailboxes. Time from revision to data collection was a median 3.1 years (range, 1.4-4.4 years).

RESULTS

Median Oxford Knee Score was 25 (interquartile range [IQR] 15) versus 31 (IQR 18) 1-3 years after revisions for unexplained pain versus aseptic loosening, P = .009. Median EQ-5D-5L was 0.6 (IQR 0.4) versus 0.8 (IQR 0.3) for unexplained pain versus aseptic loosening, P = .009. Median Forgotten Joint Score was 50 (IQR 7) versus 50 (IQR 16) for unexplained pain versus aseptic loosening, P = .905. Satisfaction was 75 (IQR 38) for unexplained pain and 50 (IQR 73) for aseptic loosening, P < .001.

CONCLUSION

Patients undergoing TKA revision for the indication of unexplained pain had worse results on PROMs than those revised for aseptic loosening. Likewise, patients revised for unexplained pain were less satisfied compared to patients revised for aseptic loosening. This information is valuable to both surgeons and patients when candidates for revision surgery are selected, to obtain the best possible outcomes.

Clinical Outcomes of Revision Total Knee Arthroplasty among Different Etiologies and Treated with a Condylar Constrained Knee Implant Supported with Cones

The first objective of this paper is to report the clinical and functional results of a cohort of patients who underwent total knee arthroplasty revision at mid–long-term follow-up. The second objective is to investigate possible differences in postoperative functional and clinical outcomes between preoperative-cause-of-revision groups. Methods: we collected data from 105 surgeries performed between January 2008 and December 2014. Eighty-five of these patients were divided into subpopulations according to the causes of revision in order to study differences regarding their outcome. All the patients underwent a standard follow-up protocol with clinical and radiological exams at 1, 3, 6, 12, 24, and 36 months and at last follow-up. During the last follow-up, patient-reported outcome measures (PROMs) were used. We implemented the functional outcomes obtained with clinical data determined by the Oxford knee score (OKS), EQ-VAS, EQ-5D-5L, Knee Society Score (KKS), and range of motion (ROM). Statistically significant differences among the medians of the groups of OKS, EQ-VAS, EQ-5D-5L, KKS, and ROM (p < 0.05) were noticed. The Dunn’s test was used to perform post hoc comparisons, and it determined where the differences lie. Results: the median follow-up was 99 months (interquartile range (IQR) 80–115). The median age was 71.5 IQR 65.1–74.8)) with no relevant differences between the groups. More patients presented a preoperative diagnosis of aseptic loosening (29%), malpositioning (28%), and infection (24%), while a preoperative diagnosis of instability (11%) and periprosthetic fracture was observed in fewer cases. For OKS, the highest median value was in the periprosthetic fracture group (43.25, IQR 32.7–45.3) and the lowest median value was in the infection group (24.8, IQR 17.4–34.8). For EQ-VAS, the highest median value was in the periprosthetic fracture group (73.0, IQR 67.0–78.0) and the lowest median value was in the instability group (39.0, IQR 36.0–48.0). For EQ-5D-5L, the highest median value was in the aseptic loosening group (0.81, IQR 0.74-0.85) and the lowest median value was in the infection group (0.44, IQR 0.32–0.60). For KKS, the highest median value was in the aseptic loosening group (84.0, IQR 81.0–88.0) and the lowest median value was in the malpositioning group (56.5, IQR 49.4–66.0). For ROM, the highest median value was in the periprosthetic fracture group (105.0°, IQR 96.0–111.0°) and the lowest median value was in the infection group (88.5°, IQR 77.5–98.0°). Conclusion: Constrained condylar knee (CCK) prostheses can also be considered a good option to manage difficult cases of total knee arthroplasty revision, with satisfactory results being maintained over time; a preoperative diagnosis of infection is associated with a worse clinical and functional outcome.

Opioid and Analgesic Use Before and After Revision Knee Arthroplasty for the Indications "Pain Without Loosening" Versus "Aseptic Loosening" - A Danish Nationwide Study

BACKGROUND

It is uncertain if patients undergoing revision knee arthroplasty for "pain without loosening" are relieved of pain. This study aimed to compare pre- and postoperative analgesic consumption by patients undergoing revision for "pain without loosening" versus "aseptic loosening" and to determine predictors for postoperative long-term opioid use.

METHODS

A retrospective nationwide study of 1,037 revisions for "pain without loosening" and 2,317 revisions for "aseptic loosening" during 1997-2018 from the Danish Knee Arthroplasty Register was carried out. Analgesic use was defined by prescription reimbursement, and long-term opioid use by prescription reimbursement in 4 consecutive quarters.

RESULTS

In the preoperative year, 37% and 29% of patients revised for "pain without loosening" and "aseptic loosening" were opioid users compared to 32% and 30% in the postoperative year. Non-steroidal anti-inflammatory drug (NSAID) use was significantly lower postoperatively for both indications (35% versus 28% for "pain without loosening" and 33% versus 25% for "aseptic loosening"). Use of other analgesics was unchanged. Long-term opioid use increased postoperatively by 4% for patients with "pain without loosening" (P = .029) and by 3% for "aseptic loosening" (P = .003). New long-term opioid users (without preoperative long-term use) were 9% for "pain without loosening" and 8% for "aseptic loosening". Predictors of new long-term opioid use were other opioid-requiring diagnoses or procedures within the first postoperative year, Charlson Comorbidity Index (CCI) ≥3, and preoperative long-term NSAID use.

CONCLUSION

The consumption of opioids decreased slightly after knee arthroplasty revision for the indication "pain without loosening", but not for "aseptic loosening". The amount of new long-term opioid users increased for both indications.

Prosthesis survival after revision knee arthroplasty for "pain without loosening" versus "aseptic loosening": a Danish nationwide study

Background and purpose - Patients having a knee arthroplasty revision for the indication "pain without loosening" may have a higher risk of re-revisions than patients revised for other indications. The primary aim of this study was to compare the survival of knee arthroplasties revised for "pain without loosening" compared with "aseptic loosening." The second was to investigate the prosthesis survival rates in 3 surgical subgroups (total knee arthroplasty (TKA)-TKA; partial revision (revision of tibial or femoral component); unicompartmental knee arthroplasty-TKA) and to compare the prosthesis survival rates for 1997-2009 and 2010-2018. Patients and methods - 4,299 revisions were identified in the period 1997-2018 from the Danish Knee Arthroplasty Register. Of these, 1,111 (26%) were performed due to "pain without loosening" without any other indications, 674 (16%) due to "pain without loosening" combined with other indications, and 2,514 (59%) due to "aseptic loosening". Survival analysis was performed by a Cox multivariate analysis and Kaplan-Meier curves were presented. Results - The cumulated proportions of re-revision after 2, 5, and 20 years were 12% (95% CI 10-14), 18% (CI 16-20), and 23% (CI 20-25) for "pain without loosening" versus 11% (CI 9.3-12), 16% (CI 14-17), and 19% (CI 18-21) for "aseptic loosening." There were no statistically significant differences between the 2 indications in repeated analyses for each of the surgical subgroups. The hazard ratio for re-revision comparing "pain without loosening" with "aseptic loosening" was 1.03 (CI 0.87-1.2). The 8-year risk of re-revision for "pain without loosening" was 22% (CI 19-26) versus 22% (CI 20-25) for "aseptic loosening" in the period from 1997-2009, and 18% (CI 15-22) versus 14% (CI 13-16) in the period from 2010-2018. Interpretation - The risk of re-revision was similar for patients having a knee arthroplasty revision for the indication "pain without loosening" compared with "aseptic loosening." However, we observed a slight improvement of prosthesis survival rates after revisions for both indications from 1997-2009 to 2010-2018. We cannot recommend for or against revision in cases with "pain without loosening" based on these data alone.

Metal allergy in primary and revision total knee arthroplasty : a scoping review and evidence-based practical approach

Aims

Metal allergy in knee arthroplasty patients is a controversial topic. We aimed to conduct a scoping review to clarify the management of metal allergy in primary and revision total knee arthroplasty (TKA).

Methods

Studies were identified by searching electronic databases: Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Embase, from their inception to November 2020, for studies evaluating TKA patients with metal hypersensitivity/allergy. All studies reporting on diagnosing or managing metal hypersensitivity in TKA were included. Data were extracted and summarized based on study design, study population, interventions and outcomes. A practical guide is then formulated based on the available evidence.

Results

We included 38 heterogeneous studies (two randomized controlled trials, six comparative studies, 19 case series, and 11 case reports). The evidence indicates that metal hypersensitivity is a rare complication with some histopathological features leading to pain and dissatisfaction with no reliable screening tests preoperatively. Hypoallergenic implants are viable alternatives for patients with self-reported/confirmed metal hypersensitivity if declared preoperatively; however, concerns remain over their long-term outcomes with ceramic implants outperforming titanium nitride-coated implants and informed consent is paramount. For patients presenting with painful TKA, metal hypersensitivity is a diagnosis of exclusion where patch skin testing, lymphocyte transformation test, and synovial biopsies are useful adjuncts before revision surgery is undertaken to hypoallergenic implants with shared decision-making and informed consent.

Conclusion

Using the limited available evidence in the literature, we provide a practical approach to metal hypersensitivity in TKA patients. Future national/registry-based studies are needed to identify the scale of metal hypersensitivity, agreed diagnostic criteria, and management strategies.

Cite this article: Bone Jt Open 2021;2(10):785–795.

Infection and periprosthetic fracture are the leading causes of failure after aseptic revision total knee arthroplasty

AIM

The purpose of this study was to clarify the medium to long term survival of aseptic revision total knee arthroplasty (RTKAs) and identify the common modes of failure following RTKAs.

MATERIALS AND METHODS

A multi-center, retrospective study included all aseptic RTKAs performed at three tertiary referral hospitals between 2003 and 2016. Patients were excluded if the revision was for prosthetic joint infection (PJI) or they had previously undergone revision surgery. Minor revisions not involving the tibial or femoral components were also excluded. Demographics, surgical data and post-operative outcomes were recorded and analyzed. Survival analysis was performed and the reasons for revision failure identified.

RESULTS

Of 235 aseptic RTKAs identified, 14.8% underwent re-revision at mean follow-up of 8.3 years. Survivorship of RTKA was 93% at 2 years and 83% at 8 years. Average age at revision was 72.9 years (range 53-91.5). The most common reasons for failure following RTKA were periprosthetic joint infection (PJI) (40%), periprosthetic fracture (25.7%) and aseptic loosening (14.3%). Of those whose RTKA failed, the average survival was 3.33 years (8 days-11.4 years). No demographic or surgical factors were found to influence RTKA survival on univariate or multivariate analysis.

CONCLUSION

PJI and periprosthetic fracture are the leading causes of re-revision surgery following aseptic revision TKA. Efforts to improve outcomes of aseptic revision TKA should focus on these areas, particularly prevention of PJI.

Association of Lumbar Degenerative Disease and Revision Rate following Total Knee Arthroplasty

Recently, a variety of studies have analyzed the potential correlation between lumbar degenerative disease (LDD) and inferior clinical outcomes after total hip arthroplasty. However, there has been limited data concerning the role of LDD as a risk factor for failure after total knee arthroplasty (TKA). The aim of our study was to determine: (1) what is the association of LDDs with TKA failure (all-cause revision) within 2 years of index arthroplasty and (2) if patients with LDD and lumbar fusion are at increased risk of TKA revision within 2 years compared with LDD patients without fusion. Data were collected from the Humana insurance database using the PearlDiver database from 2007 to 2017. To assess aim 1, patients were stratified into two groups based on a prior history of LDD (International Classification of Diseases [ICD]-9 or -10 diagnostic codes). To analyze aim 2, patients within the LDD cohort were stratified based on the presence of lumbar fusion (lumbar fusion Current Procedural Terminology code). All-cause revision rate was 3.4% among LDD patients versus 2.4% of patients with non-LDD (p < 0.001) at 2 years. Following multivariate analysis, LDD patients were at increased risk of all-cause revision surgery at 2 years (odds ratio [OR]: 1.361; 95% confidence interval [CI]: 1.238-1.498; p < 0.001) as well as aseptic loosening (OR: 1.533; 95% CI: 1.328-1.768; p < 0.001), periprosthetic joint infection (OR: 1.245; 95% CI: 1.129-1.373; p < 0.001), and periprosthetic fracture (OR: 1.521; 95% CI: 1.229-1.884; p < 0.001). Among LDD patients, patients who have a lumbar fusion had an all-cause revision rate of 5.0%, compared with 3.2% among LDD with no lumbar fusion patients at 2 years (p = 0.021). Following multivariate analysis, lumbar fusion patients were at increased risk of all-cause revision surgery (OR: 1.402; 95% CI: 1.362-1.445; p = 0.028), aseptic loosening (OR: 1.432; 95% CI: 1.376-1.489; p = 0.042), and periprosthetic fracture (OR: 1.302; 95% CI: 1.218-1.392; p = 0.037). Based on these findings, TKA candidates with preoperative LDD should be counseled that TKA outcome may be impaired by the coexistence of lumbar spine degenerative disease. This is Level III therapeutic study.

Association Between Acupuncture and Knee Surgery for Osteoarthritis: A Korean, Nationwide, Matched, Retrospective Cohort Study

Objectives: The present study was undertaken to investigate the relationship between acupuncture therapy and surgery rate. Design: Matched, retrospective cohort study. Materials and Methods: From nationwide health insurance data (2002-2013 cohort data published by the National Health Insurance Service of Korea), patients with new cases of knee osteoarthritis that occurred between January 1, 2004 and December 31, 2010 were analyzed. Patients were divided into an acupuncture group (AG) and a control group (CG), based on records of acupuncture therapy. Propensity scores were calculated by using gender, age, income level, and Charlson comorbidity index (CCI), with the groups matched at a ratio of 1:3 (AG:CG). The final analysis period was 2 years after the first acupuncture therapy for AG and 2 years after initial diagnosis for CG; surgery rates were compared between the two groups. Stratified analyses were performed based on age, gender, and income level; sensitivity analyses were performed based on the frequency and duration of acupuncture therapy. Results: Propensity score-matched AG and CG included 8,605 and 25,815 subjects, respectively. Post-matching surgery rates were 0.26 and 0.93% in AG and CG, respectively. For all age groups, AG showed a lower surgery rate than CG. In the analysis based on gender, the female group showed a significantly lower hazard ratio of 0.225. In analysis based on income level, the results of the entire group were significant, with the lower income group showing the lowest hazard ratio. In sensitivity analyses, AG tended to show a lower surgery rate than CG. Conclusions: The present study demonstrated that acupuncture therapy is associated with a low rate of surgery for knee osteoarthritis. Additional studies are needed to support this conclusion.

Cervical spine degenerative disease is an independent risk factor for increased revision rate following total knee arthroplasty

INTRODUCTION

The relationship between cervical degenerative pathology and total knee arthroplasty (TKA) revision rates is not well understood. The aim of the study was to determine whether cervical spine degenerative diseases have a role in complications following TKA within 2 years.

METHODS

Data were collected from the Humana insurance database using the PearlDiver Patient Records Database from 2007-2017. Patients who had a primary TKA were identified using Current Procedural Terminology (CPT) code 27,447, and patients with degenerative cervical disease were identified using CPT and International Classification of Diseases (ICD) codes. Data on patients' demographics, comorbidities and postoperative complications were recorded and analyzed with univariate and multivariate analysis with significance set at p < 0.05. A Kaplan-Meier analysis was conducted to estimate the 1- and 2-year rates of survival free from revision.

RESULTS

A total of 81,873 patients were included in this study. Following multivariate analysis, cervical spine degenerative disease patients were at increased risk of all-cause revision surgery following 1 year (OR: 1.342 95% CI: 1.149-1.569; p < 0.001) and 2 year (OR: 1.338; 95% CI: 1.184-1.512; p < 0.001). At 2 years, patients with cervical spine degenerative disease had a survival rate of 97.7%, while the survival rate was 99.2% among the non-cervical degenerative cohort.

CONCLUSIONS

Based on these results, patients with cervical spine degenerative pathology should be counseled that their spinal pathology may impair outcomes following TKA.

Top ten research priorities for problematic knee arthroplasty

AIMS

The James Lind Alliance aims to bring patients, carers, and clinicians together to identify uncertainties regarding care. A Priority Setting Partnership was established by the British Association for Surgery of the Knee in conjunction with the James Lind Alliance to identify research priorities related to the assessment, management, and rehabilitation of patients with persistent symptoms after knee arthroplasty.

METHODS

The project was conducted using the James Lind Alliance protocol. A steering group was convened including patients, surgeons, anaesthetists, nurses, physiotherapists, and researchers. Partner organizations were recruited. A survey was conducted on a national scale through which patients, carers, and healthcare professionals submitted key unanswered questions relating to problematic knee arthroplasties. These were analyzed, aggregated, and synthesized into summary questions and the relevant evidence was checked. After confirming that these were not answered in the current literature, 32 questions were taken forward to an interim prioritization survey. Data from this survey informed a shortlist taken to a final consensus meeting.

RESULTS

A total of 769 questions were received during the initial survey with national reach across the UK. These were refined into 32 unique questions by an independent information specialist. The interim prioritization survey was completed by 201 respondents and 25 questions were taken to a final consensus group meeting between patients, carers, and healthcare professionals. Consensus was reached for ranking the top ten questions for publication and dissemination.

CONCLUSIONS

The top ten research priorities focused on pain, infection, stiffness, health service configuration, surgical and non-surgical management strategies, and outcome measures. This list will guide funders and help focus research efforts within the knee arthroplasty community. Cite this article: Bone Joint J 2020;102-B(9):1176-1182.

Advanced Age Is Not a Barrier to Total Knee Arthroplasty: A Detailed Analysis of Outcomes and Complications in an Elderly Cohort Compared With Average Age Total Knee Arthroplasty Patients

BACKGROUND

Life expectancy and higher complication rates have made the routine use of total knee arthroplasty (TKA) in elderly patients disputed by some authors. The purpose of this study was to assess patient and implant survivorship, complication and revision rates, and patient-reported outcomes (PROMS) in a cohort of patients aged above 80 years undergoing TKA. A comparison with a propensity matched cohort of patients of average age within our database for TKA was performed.

METHODS

A retrospective review of prospectively collected data identified 644 patients over the age of 80 years undergoing a TKA within a 14-year period. After calculating the average age of all TKA patients within the reviewed database, a cohort deemed average age was created within 1 standard deviation of the average age and matched using the following criteria: gender, surgeon, diagnosis, procedure type, and year. The primary outcomes were survivorship of the implant and the patient. The secondary outcomes were complications, transfusion rates, discharge destination, and PROMS.

RESULTS

The revision rate was low for both groups (P = .051). Implant survivorship at 10 years was similar (P = .07). Mortality rate was higher in the elderly (P < .001). General complication rate was higher in the elderly (P = .031). Surgical complications rates were similar (P = .702). The PROMS at final follow-up were 4% lower in the elderly (P < .001).

CONCLUSION

TKA in the elderly is a safe procedure. With measures minimizing the perioperative complications and blood loss, the outcome can be expected to be similar to patients of average age. The projected implant and patient survivorship in the elderly cohort is long enough to suggest that TKA in the elderly could have a high impact on remaining quality of life. Level III retrospective study.

Genesis 1 posterior cruciate-retaining total knee arthroplasty with asymmetric tibial tray: An 18-to-26-year long-term clinical outcome study

BACKGROUND

To present the long-term clinical and radiological outcomes of the Genesis I posterior cruciate-retaining total knee arthroplasty (TKA) (Smith & Nephew Orthopaedics, Memphis, TN, USA) (one of the first designed with an asymmetric tibial tray).

METHODS

Prospectively collected data from 117 cemented TKAs performed on 95 patients were evaluated using this design, with a mean follow-up of 21.5 years (range, 18-26). Failures, complication rates, and clinical (both subjective and objective) and radiological outcomes were assessed for all patients.

RESULTS

Seven failures occurred (wear and structural failure of the polyethylene insert) and six revision surgeries were performed at a mean of 10 years (range, three to 14) from the index operation. No revision of either the femoral or tibial components for aseptic loosening was performed. Survivorship analysis showed a cumulative success rate of 93.53% (95% CI, 92.75-94.32%) at 20 and 25 years, with revision for any reason as an end point. All patients showed a statistically significant improvement (P = 0.001) in the Knee Society and Oxford knee rating scores.

CONCLUSIONS

This study demonstrated satisfactory long-term clinical outcomes for this TKA design, with revisions being related to polyethylene wear structural failure.

Persistent knee pain after uncomplicated total knee arthroplasty secondary to undiagnosed spondylotic myelopathy: a case report

Introduction

Knee osteoarthritis and cervical spondylotic myelopathy are both frequent disorders in the aging patient. Total knee arthroplasty is an increasingly common surgical procedure, with approximately 20% of patients describing persistent knee pain after the procedure, for which it is often difficult to find a cause. We review known reasons for pain after total knee arthroplasty and present a new clinically challenging case of persistent knee pain due to previously undiagnosed cervical spondylotic myelopathy.

Case presentation

Our patient presented with painful knee spasms after an uncomplicated total knee arthroplasty. Her workup revealed cervical spondylotic myelopathy with isolated changes in tone in the affected extremity as well as weakness and atrophy in non-painful limbs. Her clinical status improved after cervical decompression and fusion. We perform a literature review for prior reports of isolated knee pain due to cervical spondylotic myelopathy and find no previous reported association with total knee arthroplasty.

Discussion

Cervical spondylotic myelopathy is the most common spinal cord disorder in older adults. Incidence increases with age and the clinical manifestations may present with a variety of neurological findings. Careful musculoskeletal and neurologic examination is critical to an accurate and timely diagnosis.

Periprosthetic Joint Infection Is the Main Cause of Failure for Modern Knee Arthroplasty: An Analysis of 11,134 Knees

BACKGROUND

Although large series from national joint registries may accurately reflect indications for revision TKAs, they may lack the granularity to detect the true incidence and relative importance of such indications, especially periprosthetic joint infections (PJI).

QUESTIONS/PURPOSES

Using a combination of individual chart review supplemented with New Zealand Joint Registry data, we asked: (1) What is the cumulative incidence of revision TKA? (2) What are the common indications for revising a contemporary primary TKA? (3) Do revision TKA indications differ at various followup times after primary TKA?

METHODS

We identified 11,134 primary TKAs performed between 2000 and 2015 in three tertiary referral hospitals. The New Zealand Joint Registry and individual patient chart review were used to identify 357 patients undergoing subsequent revision surgery or any reoperation for PJI. All clinical records, radiographs, and laboratory results were reviewed to identify the primary revision reason. The cumulative incidence of each revision reason was calculated using a competing risk estimator.

RESULTS

The cumulative incidence for revision TKA at 15 years followup was 6.1% (95% CI, 5.1%-7.1%). The two most-common revision reasons at 15 years followup were PJI followed by aseptic loosening. The risk of revision or reoperation for PJI was 2.0% (95% CI, 1.7%-2.3%) and aseptic loosening was 1.2% (95% CI, 0.7%-1.6%). Approximately half of the revision TKAs secondary to PJI occurred within 2 years of the index TKA (95% CI, 0.8%-1.2%), whereas half of the revision TKAs secondary to aseptic loosening occurred 8 years after the index TKA (95% CI, 0.4%-0.7%).

CONCLUSIONS

In this large cohort of patients with comprehensive followup of revision procedures, PJI was the dominant reason for failure during the first 15 years after primary TKA. Aseptic loosening became more important with longer followup. Efforts to improve outcome after primary TKA should focus on these areas, particularly prevention of PJI.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Does Maximal External Tibial Component Rotation Influence Tibiofemoral Load Distribution in the Primary Knee Arthroplasty Setting: A Comparison of Neutral vs Maximal Anatomical External Rotatory States

BACKGROUND

Tibial component rotation at time of knee arthroplasty can influence conformity, load transmission across the polyethylene surface, and perhaps ultimately determined survivorship. Optimal tibial component rotation on the cut surface is reliant on standard per operative manual stressing. This subjective assessment aims to balance constraint and stability of the articulation through a full arc of movement.

METHODS

Using a cadaveric model, computer navigation and under defined, previously validated loaded conditions mimicking the in vivo setting, the influence of maximal tibial component external rotation compared with the neutral state was examined for changes in laxity and tibiofemoral continuous load using 3D displacement measurement and an orthosensor continuous load sensor implanted within the polyethylene spacer in a simulated single radius total knee arthroplasty.

RESULTS

No significant difference was found throughout arc of motion (0-115 degrees of flexion) for maximal varus and/or valgus or rotatory laxity between the 2 states. The neutral state achieved equivalence for mediolateral load distribution at each point of flexion. We have found that external rotation of the tibial component increased medial compartment load in comparison with the neutral position. Compared with the neutral state, external rotation consistently effected a marginal, but not significant reduction in lateral load under similar loading conditions. The effects were most pronounced in midflexion.

CONCLUSION

On the basis of these findings, we would advocate for the midtibial tubercle point to determine tibial component rotation and caution against component external rotation.

Revision surgery for the stiff total knee arthroplasty

AIMS

The aim of this study was to examine the results of revision total knee arthroplasty (TKA) undertaken for stiffness in the absence of sepsis or loosening.

PATIENTS AND METHODS

We present the results of revision surgery for stiff TKA in 48 cases (35 (72.9%) women and 13 (27.1%) men). The mean age at revision surgery was 65.5 years (42 to 83). All surgeries were performed by a single surgeon. Stiffness was defined as an arc of flexion of < 70° or a flexion contracture of > 15°. The changes in the range of movement (ROM) and the Western Ontario and McMasters Osteoarthritis index scores (WOMAC) were recorded.

RESULTS

At a mean follow up of 59.9 months (12 to 272) there was a mean improvement in arc of movement of 45.0°. Mean flexion improved from 54.4° (5° to 100°) to 90° (10° to 125°) (p < 0.05) and the mean flexion contracture decreased from 12.0° (0° to 45°) to 3.5° (0° to 25°) (p < 0.05). The mean WOMAC scores improved for pain, stiffness and function. In patients with extreme stiffness we describe a novel technique, which we have called the 'sloppy' revision. This entails downsizing the polyethylene insert by 4 mm and using a more constrained liner to retain stability.

CONCLUSION

To our knowledge, this is the largest series of revision surgeries for stiffness reported in the literature where infection and loosening have been excluded.

TAKE HOME MESSAGE

Whilst revision surgery is technically demanding, improvements in ROM and outcome can be achieved, particularly when the revision is within two years of the primary surgery. Cite this article: Bone Joint J 2016;98-B:622-7.

Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

BACKGROUND

The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available.

QUESTIONS/PURPOSES

A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department's perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations.

METHODS

A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department's perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes.

RESULTS

Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p <.001). On the level of the separate hospitalizations the mean direct costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p <.001). Major cost drivers were the cost of the implant and general staff. The septic implantation part was on average $3,142.87 more expensive than septic explantations (p <.001).

CONCLUSIONS

Our study for the first time provides a detailed analysis of the major direct case costs of aseptic and septic revision TKA from the hospital-department's perspective which is the basis for long-term orientated decision making. In the future, our cost analysis has to be interpreted in relation to reimbursement estimates. This is important to check whether revision TKA lead to a financial loss for the operating department.