Aims. This study aimed to describe the use of revision knee arthroplasty in Australia and examine changes in lifetime risk over a decade. Methods. De-identified individual-level data on all revision knee arthroplasties performed in Australia from 2007 to 2017 were obtained from the Australian Orthopaedic Association National Joint Replacement Registry. Population data and life tables were obtained from the Australian Bureau of Statistics. The lifetime risk of revision surgery was calculated for each year using a standardized formula. Separate calculations were undertaken for males and females. Results. In total, 43,188 revision knee arthroplasty procedures were performed in Australia during the study period, with a median age at surgery of 69 years (interquartile range (IQR) 62 to 76). In 2017, revision knee arthroplasty rates were highest for males aged 70 to 79 years (102.9 procedures per 100,000 population). Lifetime risk of revision knee arthroplasty for females increased slightly from 1.61% (95% confidence interval (CI) 1.53% to 1.69%) in 2007 to 2.22% (95% CI 2.13% to 2.31%) in 2017. A similar pattern was evident for males, with a lifetime risk of 1.43% (95% CI 1.36% to 1.51%) in 2007 and 2.02% (95% CI 1.93% to 2.11%) in 2017. A decline in procedures performed for loosening/lysis (from 41% in 2007 to 24% in 2017) and pain (from 14% to 9%) was evident, while infection became an increasingly common indication (from 19% in 2007 to 29% in 2017). Conclusion. Well-validated national registry data can help us understand the epidemiology of revision knee arthroplasty, including changing clinical indications. Despite a small increase over a decade, the lifetime risk of revision knee arthroplasty in Australia is low at one in 45 females and one in 50 males. These methods offer a population-level approach to quantifying revision burden that can be used for ongoing national surveillance and between-country comparisons. Cite this article: Bone Joint J 2022;104-B(5):613–619

Aims. To estimate the measurement properties for the Oxford Knee Score (OKS) in patients undergoing revision knee arthroplasty (responsiveness, minimal detectable change (MDC-90), minimal important change (MIC), minimal important difference (MID), internal consistency, construct validity, and interpretability). Methods. Secondary data analysis was performed for 10,727 patients undergoing revision knee arthroplasty between 2013 to 2019 using a UK national patient-reported outcome measure (PROM) dataset. Outcome data were collected before revision and at six months postoperatively, using the OKS and EuroQol five-dimension score (EQ-5D). Measurement properties were assessed according to COnsensus-based Standards for the selection of health status Measurement Instruments (COSMIN) guidelines. Results. A total of 9,219 patients had complete outcome data. Mean preoperative OKS was 16.7 points (SD 8.1), mean postoperative OKS 29.1 (SD 11.4), and mean change in OKS + 12.5 (SD 10.7). Median preoperative EQ-5D index was 0.260 (interquartile range (IQR) 0.055 to 0.691), median postoperative EQ-5D index 0.691 (IQR 0.516 to 0.796), and median change in EQ-5D index + 0.240 (IQR 0.000 to 0.567). Internal consistency was good with Cronbach’s α 0.88 (baseline) and 0.94 (post-revision). Construct validity found a high correlation of OKS total score with EQ-5D index (r = 0.76 (baseline), r = 0.83 (post-revision), p < 0.001). The OKS was responsive with standardized effect size (SES) 1.54 (95% confidence interval (CI) 1.51 to 1.57), compared to SES 0.83 (0.81 to 0.86) for the EQ-5D index. The MIC for the OKS was 7.5 points (95% CI 5.5 to 8.5) based on the optimal cut-off with specificity 0.72, sensitivity 0.60, and area under the curve 0.66. The MID for the OKS was 5.2 points. The MDC-90 was 3.9 points. The OKS did not demonstrate significant floor or ceiling effects. Conclusion. This study found that the OKS was a useful and valid instrument for assessment of outcome following revision knee arthroplasty. The OKS was responsive to change and demonstrated good measurement properties. Cite this article: Bone Joint J 2021;103-B(4):627–634

Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty. Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort. 939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements

Abstract. Introduction. In revision knee arthroplasty, rotating hinge implants (RHK) have been considered to result in higher complication rates and lower survivorship when compared to constrained condylar implants (CCK). The aims of this study were to compare patient reported outcome measures (PROMs), complication rates and survivorship of RHK and CCK used in revision arthroplasty at a single, high volume elective orthopaedic centre with previously validated bespoke database. Methodology. One hundred and eight patients who underwent revision knee arthroplasty with either CCK or RHK and matched our inclusion criteria were identified. EQ5D, Health State and Oxford Knee Scores were collected pre-operatively and at 1 year post-operatively. Complication data was collected at 6 weeks, 6 months, 1 year and 2 years post-operatively. NJR data was interrogated, in addition to our own database, to investigate implant survival. Results. There was no statistically significant difference between RHK and CCK in implant survival at two to twelve years of follow up. In addition, we observed no statistically significant difference in the PROMs scores and complication rates of the two implants. Conclusion. This study shows that both the RHK and CCK remain viable options in revision arthroplasty, the implant survival and complication rate were comparable. We recommend prospective randomised control trials with long-term follow up to further investigate the use of CCK and RHK implants in revision knee arthroplasty

Aims. The aim of this study was to determine the long-term mortality rate, and to identify factors associated with this, following primary and revision knee arthroplasty (KA). Methods. Data from the Scottish Arthroplasty Project (1998 to 2019) were retrospectively analyzed. Patient mortality data were linked from the National Records of Scotland. Analyses were performed separately for the primary and revised KA cohorts. The standardized mortality ratio (SMR) with 95% confidence intervals (CIs) was calculated for the population at risk. Multivariable Cox proportional hazards were used to identify predictors and estimate relative mortality risks. Results. At a median 7.4 years (interquartile range (IQR) 4.0 to 11.6) follow-up, 27.8% of primary (n = 27,474/98,778) and 31.3% of revision (n = 2,611/8,343) KA patients had died. Both primary and revision cohorts had lower mortality rates than the general population (SMR 0.74 (95% CI 0.73 to 0.74); p < 0.001; SMR 0.83 (95% CI 0.80 to 0.86); p < 0.001, respectively), which persisted for 12 and eighteight years after surgery, respectively. Factors associated with increased risk of mortality after primary KA included male sex (hazard ratio (HR) 1.40 (95% CI 1.36 to 1.45)), increasing socioeconomic deprivation (HR 1.43 (95% CI 1.36 to 1.50)), inflammatory polyarthropathy (HR 1.79 (95% CI 1.68 to 1.90)), greater number of comorbidities (HR 1.59 (95% CI 1.51 to 1.68)), and periprosthetic joint infection (PJI) requiring revision (HR 1.92 (95% CI 1.57 to 2.36)) when adjusting for age. Similarly, male sex (HR 1.36 (95% CI 1.24 to 1.49)), increasing socioeconomic deprivation (HR 1.31 (95% CI 1.12 to 1.52)), inflammatory polyarthropathy (HR 1.24 (95% CI 1.12 to 1.37)), greater number of comorbidities (HR 1.64 (95% CI 1.33 to 2.01)), and revision for PJI (HR 1.35 (95% 1.18 to 1.55)) were independently associated with an increased risk of mortality following revision KA when adjusting for age. Conclusion. The SMR of patients undergoing primary and revision KA was lower than that of the general population and remained so for several years post-surgery. However, approximately one in four patients undergoing primary and one in three patients undergoing revision KA died within tenten years of surgery. Several patient and surgical factors, including PJI, were associated with the risk of mortality within ten years of primary and revision surgery. Cite this article: Bone Joint J 2022;104-B(1):45–52

Abstract. Multidisciplinary team (MDT) meetings in orthopaedic surgery are evolving. The goals include patient optimisation, surgical planning and discharge arrangements, individually on a patient specific basis. In line with British Association Surgery of the Knee and GIRFT guidelines, we report our regional experience on the implementation and evolution of our regional Revision Knee Arthroplasty MDT. We undertook a retrospective review of the process, cases discussed and quality assurance conducted in the weekly MDT. Since implementation of the MDT meeting in January 2019, 550 patients with painful joint replacements have been discussed. In May 2021, we formalised our ‘terms of reference’ and ‘standard operating procedures’ which are adhered to by the consultants operating within the network, all of whom attend the meeting. A proforma has been developed and is completed for all cases capturing all pertinent information. All cases are graded according to R1, R2, or R3 complexity scale. Since its inception, the MDT has looked at all post-operative imaging, we now describe a new classification system for grading the appearances. Confirmation of the pre-operative plan and actual surgical intervention is reviewed and audited. In addition, confirmation of indication of revision at the time of operation is reviewed and validated for accuracy with benefits to the unit, individual surgeon and the NJR. In conclusion, the implementation of the revision MDT facilitating pre-operative revision arthroplasty discussion and post-operative quality assurance processes enable surgeons to educate, reflect on their practice and ensure that the highest standards of care are being provided

Aims. To compare rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications), and compare these with primary arthroplasty and re-revision arthroplasty. Methods. Patients undergoing primary knee arthroplasty were identified in the national Hospital Episode Statistics (HES) between 1 April 1997 to 31 March 2017. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes, including infection (undergoing surgery), pulmonary embolism, myocardial infarction, and stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications (e.g. loosening, instability, wear) were included in the elective indications cohort. Results. A total of 939,021 primary knee arthroplasty procedures were included (939,021 patients), of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% confidence interval (CI) 0.37 to 0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44 to 0.47). Revision arthroplasty for infection was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75 to 2.35; odds ratio (OR) 3.54; 95% CI 2.81 to 4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94 to 6.82; OR 6.23; 95% CI 4.39 to 8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. Conclusion. Patients undergoing revision arthroplasty for urgent indications (infection or fracture) are at higher risk of mortality and serious adverse events in comparison to primary knee arthroplasty and revision arthroplasty for elective indications. These findings will be important for patient consent and shared decision-making and should inform service design for this patient cohort. Cite this article: Bone Joint J 2021;103-B(10):1578–1585

Abstract. Introduction. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision and compare these with primary knee arthroplasty. Methodology. Primary and revision arthroplasty procedures were identified in the national Hospital Episode Statistics and were linked by patient and side. A logistic regression model was used to investigate factors associated with 90-day mortality (primary outcome) and secondary serious adverse outcomes. Urgent indications for revision arthroplasty were defined as infection or fracture; other indications (e.g. loosening, instability, wear) were included in the elective cohort. Results. 939,021 primary knee arthroplasty and 40,584 revision cases were included. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of PE, MI, and stroke were observed in the infection and fracture cohort. Conclusion. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency with an anticipation for increased care requirements

Abstract. Introduction. Anxiety and depression are risk factors for poor outcome following knee replacement surgery. The aim of this study was to investigate the prevalence of anxiety and depression before and after primary (pKR) and revision knee replacement (rKR). Methodology. Retrospective cohort study. 315,720 pKR and 12,727 rKR recruited from the NHS Patient Reported Outcome Measures (PROMs) programme from 2013–2021. Anxiety and depression were defined using: (i) Survey question: “Have you been told by a doctor that you have depression? Yes/No”; (ii) EQ-5D anxiety/depression domain. Rates of EQ-5D anxiety/depression were investigated at baseline and at 6-months following surgery. The prevalence of depression was investigated by patient age and gender. Results. Overall, 28,434/315,720 (9.0%) pKR and 1,536/12,727 (12.0%) rKR reported pre-operative depression. For all age groups, depression was more common in female than male patients. Prevalence of depression reduced with age (<60 years: 16.8% pKR, 22.7% rKR; 80+ years: 5.3% pKR, 5.2% rKR). Depression was most prevalent in female patients, under 60 years undergoing rKR (25.6%). Pre-operation, 109,000/303,998 (35.9%) pKR and 5,433/12,216 rKR (44.5%) reported moderate or extreme EQ-5D anxiety/depression. Post-operation, 65,351/308,914 (21.2%) pKR and 4,176/12,409 rKR (33.7%) reported moderate or extreme EQ-5D anxiety/depression. Conclusion. Anxiety and depression were prevalent in patients undergoing knee replacement surgery. Patients undergoing revision procedures, female patients and younger patients had the highest rates of depression. Large improvements in anxiety/depression were observed at early follow-up after pKR and rKR

We identified 26 tibial tubercle osteotomies (TTOs) performed in 23 revision knee arthroplasties between 2009 and 2013. Average age at last operation was 66 (33–92). Mean follow-up period was 14 months (3–33). Eleven TTOs were performed in 10 knees for single stage revisions and 15 TTOs were performed in 13 knees for 2 stage revisions in the setting of deep infection. In this infected subset 11 patients had a TTO performed at the first stage. This osteotomy was left unfixed to avoid leaving metalwork in a potentially contaminated wound, reopened, and then definitively secured with screws at the second stage. Our technique involves fashioning a long 7×1cm tibial tuberosity osteotomy without a proximal step-cut. All osteotomies united with no fractures. Minor proximal migration was noted in one case associated with screw loosening. There was no proximal migration noted in the 2 stage cases where the osteotomy had been left initially unfixed. There were no extensor lags. We conclude that TTO is a safe and reproducible procedure when adequate exposure cannot be obtained in revision knee arthroplasty. In 2 stage revisions sequential osteotomies does not decrease union rates and leaving the osteotomy unfixed after the first stage does not cause any issues

Purpose of the study. To determine the effectiveness, complications and side effects of Rivaroxaban when used for extended thromboprophylaxis in patients undergoing primary and revision knee arthroplasty. Methods. Venous Thromboembolism (VTE) prophylaxis following knee arthroplasty remains controversial. As an Orthopaedic Unit, in July 2009 we developed guidelines to help ensure that our patient management was fully compliant with National Institute for Health and Clinical Excellence (NICE) guidelines regarding risk assessment and extended oral prophylaxis following primary and revision knee arthroplasty. We opted to trial the oral anticoagulant drug Rivaroxaban for an initial period of 12 months. All patients undergoing primary or revision knee arthroplasty between 1. st. July 2009 and 30. th. June 2010 and who had no contraindications to the prescription of Rivaroxaban were included in a prospective audit aimed at determining compliance with the newly developed unit guidelines as well as the effectiveness and possible side effects/complications associated with the drug therapy. All patients were monitored for a period of 90 days post operatively. Results. A total of 415 patients were included in the audit (336 primary knee arthroplasty, 27 revision knee arthroplasty, 6 patello-femoral resurfacing, 46 medial unicompartmental knee arthroplasty). Of this group eight had a confirmed VTE (six deep vein thrombosis, two pulmonary embolism). A further 29 patients had post-operative complications which may be attributed in part to the action of Rivaroxaban. The drug was discontinued prematurely for 22 patients. Conclusions. Our results indicate that Rivaroxaban is effective in providing extended VTE prophylaxis to patients undergoing knee arthroplasty surgery. However, as anticipated, anticoagulation therapy does cause associated wound problems

Purpose: To examine the outcome of primary and revision knee arthroplasty in very elderly patients. Methods and Results: Patients in their 90th year of life who underwent primary or revision knee arthroplasty between January 2000 and September 2007 were identified. Data was collected regarding demographics, ASA grade, co-morbid factors, complications, length of inpatient stay, the need for transfusion and discharge destination. Thirty day, 1 year and current mortality figures were calculated. Twenty one procedures were performed on 18 patients with a mean follow up of 18.8 months (3–57.9). There were 14 primary total knee replacements and 7 revision procedures. The mean age at the time of surgery was 90 years and 10 months (89 years 1 month to 94 years 4 months). The majority of patients were female (15). All patients were ASA grade 2 or 3. The average orthopaedic inpatient stay was 17 days. Thirty percent of patients required a period of further inpatient rehabilitation or convalescence after discharge from our institution. Nine patients experienced a post-operative complication. Mortality at 30 days was 0%, at 1 year 6% (1/16), and is currently 17% (3/18). Conclusion: Very elderly patients are able to tolerate primary and revision knee arthroplasty although there is a high rate of peri-operative complications. We propose that there should be a different tariff for arthroplasty procedures in extremely elderly patients to reflect the increased rate of complications and prolonged postoperative hospital stay

We present detailed information about early morbidity after aseptic revision knee replacement from a nationwide study. All aseptic revision knee replacements undertaken between 1st October 2009 and 30th September 2011 were analysed using the Danish National Patient Registry with additional information from the Danish Knee Arthroplasty Registry. The 1218 revisions involving 1165 patients were subdivided into total revisions, large partial revisions, partial revisions and revisions of unicondylar replacements (UKR revisions). The mean age was 65.0 years (27 to 94) and the median length of hospital stay was four days (interquartile range: 3 to 5), with a 90 days re-admission rate of 9.9%, re-operation rate of 3.5% and mortality rate of 0.2%. The age ranges of 51 to 55 years (p = 0.018), 76 to 80 years (p < 0.001) and ≥ 81 years (p < 0.001) were related to an increased risk of re-admission. The age ranges of 76 to 80 years (p = 0.018) and the large partial revision subgroup (p = 0.073) were related to an increased risk of re-operation. The ages from 76 to 80 years (p < 0.001), age ≥ 81 years (p < 0.001) and surgical time > 120 min (p <  0.001) were related to increased length of hospital stay, whereas the use of a tourniquet (p = 0.008) and surgery in a low volume centre (p = 0.013) were related to shorter length of stay. . In conclusion, we found a similar incidence of early post-operative morbidity after aseptic knee revisions as has been reported after primary procedures. This suggests that a length of hospital stay ≤ four days and discharge home at that time is safe following aseptic knee revision surgery in Denmark. Cite this article: Bone Joint J 2014;96-B:1649–56

Purpose. Although classic teaching holds that the least amount of constraint should be implanted, there is very little in the literature to substantiate this. This study attempts to quantify the influence of constraint and various indications upon functional outcome following aseptic first time revision knee arthroplasty. The null hypothesis was that the level of constraint and indication for surgery would not influence the functional outcome following revision knee replacement. Methods. A single centre prospective study was performed to examine the outcome for 175 consecutive total revision knee replacements performed between 2003 and 2008 with a minimum follow-up of two years. Patient reported outcome data was used to determine the influence of final level of component constraint and its relationship with primary indication for surgery. Results. All patients were found to have a significant improvement for WOMAC pain, function and stiffness score (p< 0.001) and physical functioning, role physical, bodily pain and social functioning components of SF-36 score (p< 0.05). 69% were satisfied with the overall procedure. WOMAC function, pain and stiffness score was significantly worse for patients revised for instability (27%) compared to that for aseptic loosening (46%). A significantly higher proportion of patients were satisfied with the procedure (p< 0.001), had a better quality of life (p=0.004) and would have the surgery (p=0.005) again in the aseptic loosening group as compared to the instability group. Revision to a higher level of constraint did not improve knee function irrespective of the primary indication for surgery. Conclusion. Revision for an instability pattern irrespective of choice of new device was met with significantly poorer functional outcome

Aims

The aim of this study was to identify variables associated with time to revision, demographic details associated with revision indication, and type of prosthesis employed, and to describe the survival of hinge knee arthroplasty (HKA) when used for first-time knee revision surgery and factors that were associated with re-revision.

Abstract. Introduction. Our aim was to investigate trends in the incidence rate and main indication for revision knee replacement (rKR) over the past 15 years in the UK. Methodology. Cross-sectional study from 2006 - 2020 using data from the National Joint Registry (NJR). Crude incidence rates were calculated using population statistics from the Office for National Statistics. Results. Annual total counts of rKR increased from 2743 procedures in 2006 to 6819 procedures in 2019 (149% increase). The incidence rate of rKR increased from 6.3 per 100,000 adults in 2006 (95% CI 6.1 to 6.5) to 14 per 100,000 adults in 2019 (95% CI 14 to 14). Annual increases in the incidence rate of rKR became smaller over the study period. The incidence of rKR was highest in patients aged 70–79 years (50 per 100,000 adults [95% CI 48 to 52]). Aseptic loosening was the most frequent indication for rKR overall (20.5% procedures). However, rKR for aseptic loosening peaked in 2012 and subsequently decreased. rKR for infection increased incrementally over the study period to become the most frequent indication for rKR in 2019 (2.7 per 100,000 adults [95% CI 2.6 to 2.9]). Infection accounted for 17.2% first linked rKR, 36.7% second linked rKR and 50.7% third or more linked rKR. Conclusion. Recent trends suggest slowing of the rate of increase in the incidence of rKR. Infection is now the most common indication for rKR, following recent decreases in rKR for aseptic loosening. Infection was prevalent in re-revision KR procedures

Purpose: Total knee arthroplasty is one of the most successful modern surgical interventions with excellent clinical outcomes and implant survivorship. Nevertheless, with the increasing numbers of primary knee replacements being performed and increasing life expectancy, the need for revision arthroplasty continues to grow and is expected to grow considerably in to the future. Stemmed implants are commonly used in revision knee arthroplasty to provide adequate support for the joint interfaces. Controversy exists amongst surgeons as to the relative merits of cemented versus uncemented stems in revision knee arthroplasty. Cementing stemmed components in revision knee arthroplasty surgery is well established, and has well documented success rates. Though in widespread use, there is little data published regarding the technique of cementing short stubby tibial stems in revision TKA. We describe modes of failure in knee arthroplasty, our technique for revision, and early outcomes for this patient cohort. Method: This was a retrospective analysis of a cohort of patients who have undergone revision knee arthroplasty. We evaluated the early clinical results looking for early failure in patients who have undergone revision knee arthroplasty using a short cemented tibial stem. All patients were operated on by a single surgeon in a single hospital. Baseline data was collected on all patients (age, gender, BMI, reason for revision, preoperative knee scores, details of surgery). Latest follow up clinical data, knee scores, and x-rays were evaluated to determine early patient outcomes and identify any implant or technical failure. Results: Between 2003 and 2009, 77 of 241(32%) revision knee arthroplasty surgeries were performed using a short cemented tibial stem. This cohort of 77 patients included 49 females and 27 males. Eight knees (10%) were operated in two stages in the setting of deep infection. Average follow up for this group was 17 months (range 4 to 60 months). One patient developed a deep prosthetic infection requiring further revision surgery. No other patients to our knowledge have undergone further surgery and none have further surgery planned for mechanical failure or significant malalignment of the tibial prosthesis. No failure or early mechanical complication of using a short cemented tibial stem was identified clinically or radiographically. Conclusion: We surmise the use of short cemented tibial stems in revision knee arthroplasty surgery is a safe and effective technique with potential advantages over longer cemented or uncemented stems. We have recorded satisfactory early outcomes, and continue to use this technique

Objectives. The purpose of this study was to develop an accurate, reliable and easily applicable method for determining the anatomical location of the joint line during revision knee arthroplasty. Methods. The transepicondylar width (TEW), the perpendicular distance between the medial and lateral epicondyles and the distal articular surfaces (DMAD, DLAD) and the distance between the medial and lateral epicondyles and the posterior articular surfaces (PMAD, DLAD) were measured in 40 knees from 20 formalin-fixed adult cadavers (11 male and nine female; mean age at death 56.9 years, . sd. 9.4; 34 to 69). The ratios of the DMAD, PMAD, DLAD and PLAD to TEW were calculated. Results. The mean TEW, DMAD, PMAD, DLAD and PLAD were 82.76 mm (standard deviation (. sd. ) 7.74), 28.95 mm (. sd. 3.3), 28.57 mm (. sd. 3), 23.97 mm (. sd. 3.27) and 24.42 mm (. sd. 3.14), respectively. The ratios between the TEW and the articular distances (DMAD/TEW, DLAD/TEW, PMAD/TEW and PLAD/TEW) were calculated and their means were 0.35 (. sd. 0.02), 0.34 (. sd. 0.02), 0.28 (. sd. 0.03) and 0.29 (. sd. 0.03), respectively. Conclusion. This method provides a simple, reproducible and reliable technique enabling accurate anatomical joint line restoration during revision total knee arthroplasty. Cite this article: B. Ozkurt, T. Sen, D. Cankaya, S. Kendir, K. Basarır, Y. Tabak. The medial and lateral epicondyle as a reliable landmark for intra-operative joint line determination in revision knee arthroplasty. Bone Joint Res 2016;5:280–286. DOI: 10.1302/2046-3758.57.BJR-2016-0002.R1

Aim: The purpose of this study was to report our experience mid to long-term results of hybrid cement fixation in revision total knee arthroplasty. Methods: Patients who underwent revision total knee arthroplasty using a hybrid cement technique (press-fit diaphyseal fixation and cemented metaphyseal fixation) with a titanium fluted revision knee implant were reviewed. There were 127 patients. Mean age at surgery was 71 years (range 41–94 years). There were 56 males and 71 females. Mean follow-up was 5 years (range, 2–12 years). A Kaplan-Meier survivorship analysis using an end-point of revision surgery or radiographic loosening was employed to determine probability of survival at 5 and 10 years. Results: 127 patients (135 knees), 31 patients (36 knees) died and 2 patients (2 knees) were lost to follow-up. Six patients (six knees) were revised at a mean of 3.5 years (range 1–8 yrs). Of the 6 revisions, two were for re-infection, two were for (MCL) instability, and two were for aseptic loosening. Mean Knee Society clinical and functional scores were 86 and 55 points, respectively. The mean range of motion was 108 degrees. End of stem pain was not reported in this group of patients. Kaplan-Meier survivorship analysis revealed a probability of survival free of revision for aseptic loosening of 98% at 12 years. Discussion: The results of this study suggest that the use of a hybrid cement technique in revision knee arthroplasty can provide good mid to long-term results. Radiographic analysis has shown continued satisfactory appearances regardless of constraint, stem size and augments. Our experience has shown that the survivorship of a hybrid fixation technique for revision knee arthroplasty is comparable to reported long-term survivorship of cemented revision knee arthroplasty

Introduction. Bone loss in the distal femur and proximal tibia is frequently encountered with both complex primary and revision knee replacement surgery. Metaphyseal sleeves provide a good option for enhanced fixation in managing such defects on both the tibia and femur. We present our results in 48 patients (50 knees) with a minimum 12 month follow up (range 12 to 45). Methods. 48 patients (50 knees) who had revision knee arthroplasty for either septic or aseptic loosening. All were graded Type II or III using the Anderson Orthopaedic Research Institute (AORI) grading system of both femoral and tibial defects. A large portion of aseptic loosening revisions were for extreme osteolysis of a bicondylar knee prosthesis. Results. 52% had tibial sleeves only, 38% had both tibial and femoral sleeves and the remainder had only femoral sleeves inserted. All knee radiographs at final follow-up showed well-fixed osteointegrated components without component migration or clinically significant osteolysis. Two knees were treated with multiple arthroscopic washouts for infection. Two knees subsequently underwent manipulation under anaesthesia with good improvement in range of movement. One subsequently developed Complex Regional Pain Syndrome. No femoral or tibial components were revised. The average pre-operative Oxford Knee Score was 22 (12 to 38) and subsequently improved to 38 (12 to 45) post-operatively. Discussion and conclusions. Our early results show encouraging signs that porous titanium sleeves are a good option when managing large metaphyseal bone loss in both femur and tibia especially in revision arthroplasty. Post operative complications were low and functional outcome scores were comparable with more traditional knee revision arthroplasty techniques in the presence of bone loss

Authors have been using kinematic computer navigation for a total knee replacement surgery since 2003. A contribution and advantage of computer navigation is well recognized. Exact guidance of both tibial and femoral osteotomy along with precise soft tissue balance respecting individual anatomic constitution is achieved by exact collection and computer evaluation of data by a use of special sensors and probes. Use of kinematic navigation in experienced hands minimizes deviation from physiological mechanical Mikulicz axis. This is considered the most important step to achieve a good long term outcome after total knee arthroplasty. We have been recently using Brain Lab kinematic navigation system in both primary and revision knee arthroplasties. 200 primary and 20 revision knee arthroplasties are included in the retrospective 3 year follow up study. A navigated revision surgery is recently performed only in cases where the axial deformity does not exceed 10 degrees and where no significant bone loss is presented (bone defects less that ½ cm). Standard cemented components are used in both primary and revision cases. A primary navigated knee arthroplasty had no exclusion criteria in the above study. Technique: Medial patellar approach technique is used, navigation probes are placed in standard distal femoral and proximal tibial position. Data are collected using navigation probes and sensors. Loosen components and cement are removed next. Navigated proximal tibial osteotomy, distal femoral osteotomy and soft tissue balance are performed. Gentamycin cementing of standard components (tibia first) is performed at the end. A final verification of component balance and data storage terminates the procedure. No need for conversion to a revision knee system using stem and wedges was noticed in the above series. Following the above inclusion criteria standard cemented implants were used only. We conclude that the use of navigation in cases of relatively uncomplicated knee revision arthroplasty guaranties good mid term outcome, good soft tissue balance, saves money on expensive knee revision systems and guaranties an alternative of second stage revision surgery with a use of extensive revision systems. Standard implant selection does not apply for those with deep bone defects and axial deformation higher than 10 degrees

The aim of this study was to ascertain if a correlation exists between the indication for revision and the clinical outcome in revision total knee replacement. Methods: We analysed the data of 81 revision knee arthroplasty patients performed at Wrightington Hospital with an average follow-up of 31 months (1yr – 6yrs). All patients had semi-constrained prosthesis implanted (PS-PFC or TC3, Depuy). The indications for revising the total knee arthroplasty in each patient were noted and the clinical outcome was determined using a patient satisfaction questionnaire. Results: Of the 81 patients, 18 were enthusiastic with the clinical outcome, 38 were satisfied, eight were non-committal and 17 were disappointed. Indications for revision in our series were aseptic loosening (31 patients), implant failure (21 patients), instability (14 patients), pain (eight patients) and infection (seven patients). Correlation between the indication for revision and the clinical outcome are detailed in the table below. Sixteen per cent of patients revised for aseptic loosening were non-committal or disappointed with the outcome in comparison with 33.3% revised for implant failure, 21.4% revised for instability, 62.5% revised for pain and 71.4% revised for infection. Conclusion: The indication for revision does affect the clinical outcome in revision knee arthroplasty. Patients undergoing revision knee arthroplasty for infection and pain are less likely to be satisfied with the clinical outcome of revision surgery

It is usually assumed that there is a correlation between the number of previous operations and the clinical outcome of revision knee arthroplasty though it has not been studied and published. We reviewed our series of 81 revision knee arthroplasty patients to ascertain if a correlation exists. All patients had a semi-constrained prosthesis implanted. Methods: We analysed the data of 81 revision knee arthroplasty patients performed at Wrightington Hospital with an average follow-up of 31 months (1yr – 6yrs). The number of previous operations on each knee were noted and the clinical outcome was determined using a patient satisfaction questionnaire. Results: Of the 81 patients; 18 were enthusiastic with the clinical outcome; 38 were satisfied; eight were non-committal; 17 were disappointed. Seventy four per cent of patients with one previous operation were enthusiastic or satisfied with the revision surgery outcome in comparison to 55.5% and 0% of patients with two and three previous surgery respectively. Conclusion: The trend from the above figures suggests that as the number of previous operations increases the likelihood of satisfactory clinical outcome decreases, in revision total knee replacement using semi-constrained prosthesis

The prospective evaluation of two hundred and seven symptomatic total knee arthroplasties presenting for revision total knee arthroplasty is reported. On univariate analysis patients who had infection differed significantly (p< .001) from those without infection with regards to: elevated ESR, CRP, positive aspiration, and history of; revision procedure less than two years since last surgery, early wound problems, ongoing pain since index procedure, and discharging wound. On multivariate analysis elevated ESR or CRP, positive aspiration, pain since index procedure and early wound complications were significant predictors of infection (p< .05). These variables were then used to formulate an evidence-based multivariate predictive algorithm to assist the clinician in decision making prior to surgery. Differentiating septic from aseptic failure of total knee arthroplasty on the basis of clinical features and diagnostic tests can be troublesome for the clinician. The purpose of this paper is to describe significant differences between cases of septic and aseptic failure of total knee arthroplasty. The incorporation of these variables into a practical multivariate clinical prediction algorithm can provide assistance in establishing the diagnosis of infection prior to revision knee arthroplasty. A simple clinical prediction algorithm can assist in the diagnosis of infection in patients with painful total knee arthroplasty. Patients with five of five criteria have a 99% probability of infection whereas patients with zero of five criteria have a 1% probability of infection. This is the first multivariate evidence-based clinical prediction algorithm presented for use in decision making prior to revision total knee arthroplasty. The surgeon can use the information derived from clinical and laboratory assessment to compute an approximate pre-operative probability of infection prior to surgery (see table). On multivariate analysis elevated ESR or CRP, positive aspiration, pain since index procedure and early wound complications were significant predictors of infection (p< .05). These variables were then used to formulate an evidence-based multivariate predictive algorithm to assist in clinical decision making. Prospective data was collected on two hundred and seven symptomatic knee arthroplasties presenting for revision arthroplasty. A multivariate logistic regression model was used to determine the probability of infection using five significant variables. Combinations of these five variables can provide the clinician with an estimate of the probability of infection prior to revision knee arthroplasty. Please contact author for tables and/or charts

Aims: To determine the kneeling ability in 3 groups of patients who have undergone either Unicondylar, Primary, or Revision knee arthroplasty. Methods: A questionnaire was designed to determine the kneeling ability of patients who have undergone knee arthroplasty surgery. The ‘Kneeling’ questionnaire along with a Western Ontario and MacMaster Osteoarthritis Index (WOMAC) questionnaire was sent to 191 patients of whom, 27 have had Unicondylar, 105 had Primary and 59 Revision knee arthroplasty. Results: The mean follow-up time for assessment for each of the 3 groups of patients were; Unicondylar = 3.32 years, Primary = 5.30 years and Revision = 5.06 years. The mean total WOMAC scores for the 3 groups were; Unicondylar = 13.96, Primary = 22.10, and Revision = 38.67. The percentage of patients who underwent knee arthroplasty that found it impossible to kneel were; Unicondylar = 18%, Primary = 36% and Revision = 66%. The commonest reasons why patients found kneeling difficult were; pain and stiffness around the knee prosthesis, fear of harming the prosthesis and sensory deficit around the knee. Visual Analogue Pain scores for kneeling in the 3 patient groups were, Unicondylar = 5.6, Primary = 7.12, Revision = 9.18. A minimum of 30% of patients in each of the 3 groups reported their daily lives were moderately-severely affected due to their difficulty in kneeling following knee arthroplasty. At least 60% of the patients in each group reported they would like to have better kneeling ability. Conclusion: Unicondylar knee arthroplasty patients have better WOMAC scores and find kneeling easier than patients who have undergone Primary knee arthroplasty (p< 0.01). The Primary group have better WOMAC scores and find kneeling easier than the Revision group (p< 0.001). Kneeling is considered important in patients who have undergone knee arthroplasty. Poor kneeling ability in patients may restrict their daily activities

Aim: To report our experience of revision knee arthroplasty with respect to surgical technique, joint line restoration and clinical outcome. Methods: A clinical and radiological review was made of 45 knee revisions performed between 1996 to1998 using the Kinemax system. The reasons for revisions were infection (19), wear (11), loosening (seven), base-plate fracture (four) and instability (five). A primary prosthesis was used in 10 (22%), a posterior stabiliser in 24 (53%) and a superstabiliser in 11 (24%). WOMAC pain and function scores, arc of motion and measurements of joint line and patellar height were made. Results: Three patients had died. Three knees had been revised a second time for instability and one had been arthrodesed for infection. The mean joint line elevation was 1.3mm compared with the primary and depressed 1.6mm when compared with the natural knee. Twenty-seven percent had patella infera and 13% had patella alta. A significant correlation was found between the change in patellar tendon length and the change in the joint line. The flexion arc was significantly improved from 83 degrees to 95 degrees. No relationship was found between the clinical outcomes and the changes in the joint-line. There were two deep infections (4.4%) and five knees were unstable. The three cases of flexion instability were due to failure to reconstruct adequately the antero-posterior (AP) diameter of the femur. Conclusions: By restoring the level of the joint-line, a less constrained prostheses can be used in revision surgery with good functional results. The AP diameter of the femur must also be reconstructed to avoid flexion instability

Stem dissociation in modular revision knee replacement due to failure of the frictional lock of the Morse taper has been reported in the literature. However, the medium and long-term implications of stem dissociation are unknown, as clinical outcomes have not been reported. We report a series of 10 cases in which there was intra-operative dissociation of the tibial stem. Between 1994 and 1999, 98 patients underwent revision total knee replacement for aseptic loosening at our institution. Ten of these patients were noted to have tibial stem dissociation, apparent on the immediate post-operative radiographs. The senior author (RWP) performed all procedures and used a standardized operative technique. The Co-ordinate modular knee revision system was used in all cases. The quality of the bone was noted in all the cases intra-operatively; and was graded as 1) sound bone, 2) soft but intact, 3) soft and fractured cortex. Our study demonstrates that the tibial stem dissociation did not cause any significant detriment to the clinical outcome on minimum follow-up of six years in nine cases where the tibial metaphyseal cortical rim was intact. In one case, where the medial tibial plateau had a cortical defect, the prosthesis drifted into varus mal-alignment and the patient required a further revision for aseptic loosening. We therefore question whether long canal filling tibial stems are necessary in all revision total knee replacements particularly when the cortical rim is intact and a non-constrained poly-ethylene insert is used

We report on five-ten year results of AORI type two bone defects treated with modular augments in revision knee surgery. 102 revision knee arthroplasties with type two defects were treated with augments & stems and minimum five-year follow-up were prospectively studied. 15 patients (16 knees) died with retention of their prosthesis, 7 knees had incomplete follow-up. There were 79 remaining knees with complete follow-up of 7+−2 years (range: 5 – 11). The presence of non-progressive radiolucent lines around the augment in 20% of knees was not associated with poorer knee scores, range of motion, component survival or type of insert used (p> 0.05). Kaplan-Meier survival of the components was 92+− 0.03% at 11 years (95%CI:10.3–11.2). We support the use of modular augmentation devices to treat type 2 defects in revision knee surgery and conclude that theoretical concerns of fretting and loosening based on 5 – 10 year clinical data are unfounded

Introduction. We wished to quantify the influence of constraint and various principal indications upon functional outcome following aseptic first time revision knee arthroplasty. Methods. In this single centre, prospective study we have looked into the outcome of 175 total revision knee replacement performed between 2003 and 2008 at a minimum follow-up of 1 year. Data was refined to allow for examination exclusively of those cases where the level of constraint was increased from cruciate retaining or cruciate sacrificing knee replacement to either non linked constrained implant (condylar constrained) or linked constrained (rotating hinge) prosthesis. Results. At one year significant improvement (p<0.001) of WOMAC pain, function and pain score was seen. Significant improvement (p<0.05) was noted in physical functioning, role physical, bodily pain and social functioning components of SF-36 score. 69% were satisfied with the overall procedure. WOMAC function, pain and stiffness score was significantly worse for patients revised for instability (27%) as compared to that for aseptic loosening (46%). A significantly higher proportion of patients were satisfied with the procedure (p<0.001); had a better quality of life (p=0.004) and would have the surgery (p=0.005) again in the aseptic loosening group as compared to the instability group. Level of constraint did not make any statistically significant difference in the outcome within either group. The postoperative outcome scores for patients receiving two different levels of constraint was statistically not different. We found that increasing the level of constraint to linked constrained implant significantly (p<0.001) deteriorated the ability to descend from stairs (Figure 4). Conversely it had a positive influence (p=0.01) on ability to walk on flat. Conclusion. Patients undergoing revision surgery for instability exhibited poorer functional knee scores at 1 year. The degree of constraint within the revision construct did not significantly alter this change irrespective of aetiology

Patient reported outcome measures (PROMs) after total knee arthroplasty (TKA) are typically used to assess longitudinal change in pain and function after total knee arthroplasty (TKA). The Patient's Knee Implant Performance (PKIP) score was developed to evaluate outcomes more broadly including function, stability, confidence, and satisfaction. Although validated in patients having a primary TKA, the PKIP has not been evaluated as an outcome measure for patients having revision TKA. This study examined patient outcomes at one year following primary and revision TKA measured using the PKIP, compared to Oxford Knee Scores.

A retrospective analysis of pre-operative and one-year post-operative outcomes was completed for 39 patients (21 female) who had primary (n=27) or revision (n=12) TKA with a single surgeon between 2017 and 2020. The mean age was 69.2±7.4 years, and mean weight 87.4± 5.1kg. The change over time and correlation between the self-reported outcome measures was evaluated.

There was a significant improvement in the PKIP overall score at the 12-month follow-up (32± 13 v 69± 15, p= <0.001), with no significant difference between groups (3.3 points, p=0.50). Among the PKIP sub-scores, there was a significant improvement in knee confidence (3.5±2 vs 7.7±2; p<0.001), stability (3.4±2 vs 7.4±3; p<0.001) and satisfaction (2.5±1.7 vs 6.6±3, p<0.001). Between group differences in PKIP sub-scores one year after surgery were small and non-significant. For all patients, the OKS and PKIP scores were moderately correlated before surgery (r=0.64, p=<0.05), and at 1 year after surgery (r=0.61, p= <0.001).

Significant improvements in knee confidence, stability, and satisfaction one year after TKA were identified from the PKIP responses, with no significant difference between primary and revision surgery. The moderate correlation with the OKS suggests these questionnaires measure difference constructs and may provide complementary outcome information in this patient cohort.

Background. Both surgeon and hospital volume influence patient outcomes following revision knee arthroplasty. Purpose. To audit all centres performing revision knee procedures in England and Wales over a 2-year period. All centres were audited against two pre-defined standards linked to hospital volume. Operative volume should be greater than 10 revisions per year;. More than 2.5 revisions should be performed for every 100 primary arthroplasties implanted. Methods. Data for 9659 knee revisions performed in 359 different centres between 01/07/08 and 30/06/10 was accessed from the National Joint Registry for England and Wales. For each centre information on the volume of primary and revision knee procedures undertaken during this period was available and was used as the basis for audit. Results. During the 2-year study period 396 different centres performed 153133 primary knee arthroplasties. Of these 359 (91%) performed 9659 knee revisions, equivalent to 6.2 revisions for every 100 primary arthroplasties performed. Revision centres included 208 (58%) NHS hospitals performing 8148 revisions, 141 (39%) independent hospitals performing 1258 revisions and 10 (3%) Independent Sector Treatment Centres (ISTC) performing 253 revisions. The median number of revisions performed per hospital was 7 per year (Range 1 to 144). Volume differed dependent upon hospital type (NHS=14/year vs. Independent=3/year, p< 0.001). Two hundred and twelve (59%) centres performed < 10 revisions per year and thus fell below the audit standard. Eighty of these centres also performed < 2.5 revisions per 100 primaries. Of the 141 independent hospitals 128 (91%) fell below the suggested standards for revision volume. Conclusions. A significant number of institutions are performing only a small volume of knee revision procedures. To ensure safe and sustainable practice with better outcomes, consideration should be given to rationalising the revision service in fewer centres

Infection after knee arthroplasty is a devastating complication. Our aim is to present our outcomes of treating infected knee replacements at a tertiary referral centre. We performed a consecutive, retrospective case series of all revision knee arthroplasty for infection between January 2006 and December 2008. Case notes were reviewed and data collated on the date and institution of primary arthroplasty, procedures undertaken at our institution, microbiology and bone loss post first stage, serological markers (C-reactive protein, ESR) prior to second stage and outcome. During this three year period we performed 430 knee revision operations. 51 were in the presence of deep chronic infection. 90% were referred from other hospitals. Overall infection was successfully eradicated in 69%. Nineteen patients underwent repeat two-stage and overall eleven (58%) patients had successful eradication of infection with multiple two-stages. Of these 47% had F3/T3, the highest grading of Anderson Orthopaedic Research Institute bone loss indicating no metaphyseal bone. A further 12% had bicondylar deficiency on the tibia and no femoral metaphyseal bone (F3/T2b). Multidrug resistance present in 69% and 47% were infected with multiple organisms. All members of the unsuccessful outcome group had at least one multidrug resistant organism compared to 43% in the successful cohort (P=0.0002). Multiple organisms are associated with an unsuccessful outcome (P=0.056). Serological markers were not significantly different between the successful and unsuccessful outcome groups. Where the referring hospital had attempted revision and failed, the chance of eradicating infection dropped from 75% to 58% and the rate of above knee amputation was twelve times higher (3% vs. 36%). Custom constrained, rotating hinge prostheses enable aggressive soft tissue debridement including ligaments. Successful two-stage requires a multidisciplinary approach including tissue viability nurses, microbiologists and plastic surgeons. Where units lack revision expertise this series suggests early referral increases the chance of limb salvage

Aims

In the last decade, perioperative advancements have expanded the use of outpatient primary total knee arthroplasty (TKA). Despite this, there remains limited data on expedited discharge after revision TKA. This study compared 30-day readmissions and reoperations in patients undergoing revision TKA with a hospital stay greater or less than 24 hours. The authors hypothesized that expedited discharge in select patients would not be associated with increased 30-day readmissions and reoperations.

Abstract

Deep surgical infections are a serious complication of total knee arthroplasty (TKA). Various protocols exist for treating these infections, each with its own advocates. In this series we report the one to five year follow-up of infected TKA that were treated with a two-stage revision knee replacement at the Glasgow Royal Infirmary between December 2003 and March 2009. 48 patients were identified from the hospital database. 6 of these were excluded as they did not meet the stipulated infection criteria. Another patient was excluded as no notes were available thereby the infection status could not be determined. Another 8 patients were excluded as these only had a first stage. 33 patients (16 male) average age 67y (49–88) met the inclusion criteria. Mean BMI was of 31.62 (19–47) and 8 patients suffered from rheumatoid arthritis. At presentation, the median for the ESR, CRP and WCC were 70.5, 133 and 8.5 respectively. The infective organism was identified in 22 patients. Following the first stage, the patients were treated with antibiotics (initially intravenous followed by oral) for an average of 11.8 weeks (4–52 weeks). This procedure failed to eliminate the infection in 6 patients (18.18%) who had further re-admissions for infection of the affected prosthesis. The resultant success rate is of over 80% which is comparable to literature data (success rates of 41% to 96% quoted). For these patients, the average time to review was 25.13 months (12–67months). At review these patients had a mean extension of 2.17° (0–10°) and a mean flexion of 98.26 (70–120°). These patients were all satisfied with their outcome. Our results show a high successful rate of elimination of infection when a two-stage revision is used for infected knee prosthesis with over 80% of patients free of infection

Aims:We sought to develop and validate a classiþcation system for assessing PFJ status prior to revision surgery. Methods: The classiþcation system grades the condition of the PFJ by describing both the patella bone stock and the patello-femoral tracking. The system was analysed for its reliability by assessing both intra- and inter-observer variability. From our database of 110 patients who underwent revision knee arthroplasty, 66 cases were selected at random. Each patient had both pre and post-operative radiographs to classify. 145 sets of radiographs, each set consisting of an AP, lateral and skyline patella view, were studied. Three clinicians graded all radiographs according to the classiþcation system on 2 separate occasions. These assessments were performed at least 6 weeks apart. The results were analysed by an independent observer who was blinded. Both intra- and inter-observer agreement was quantiþed using kappa values. Results: Inter-observer kappa values between observers A& B, B& C and C& A were 0.89, 0.96 and 0.82 respectively. Intra-observer kappa values were 0.94, 0.87 and 0.97 for the 3 clinicians. This indicates excellent levels of agreement. Conclusions: The proposed classiþcation system provides a convenient, spe-ciþc, descriptive and reproducible method of denoting PFJ status. Our system may be used to accurately communicate and compare PFJ characteristics. This will aid planning of surgical intervention and allow comparison of results and techniques in revision knee arthroplasty

BACKGROUND. High-dose antibiotic cement spacers are commonly used to treat prosthetic joint infections following knee arthroplasties. Several clinical studies have shown a high success rate with antibiotic cement spacers, however there is little data on the systemic complications of high-dose antibiotic spacers, particularly acute kidney injury (AKI). This study aims to determine the incidence of AKI and identify risk factors predisposing patients undergoing staged revision arthroplasty with antibiotic cement spacers. METHODS. A single-institution, retrospective review was used to collect and analyze clinical and demographic data for patients who underwent staged revision total knee arthroplasty with placement of an antibiotic-impregnated cement spacer from 2006 to 2016. A search was made through specific procedure (DRG) and diagnostic (CD) codes. Baseline descriptive data were collected for all patients including age, sex, medical comorbidities, type and quantity of antibiotics used in the cement spacer, pre- and postoperative hemoglobin (Hg), BMI, smoking status, peak creatinine levels, and random vancomycin levels. Acute kidney injury was defined as a more than 50% rise in serum creatinine from a preoperative baseline within 90 days postoperatively. RESULTS. A total of 54 staged revision TKA surgeries performed by 5 different surgeons between 2006 and 2016. The total incidence of AKI was 31% (n=17). There was a significant positive association between change in creatinine level and use of oral/intravenous antibiotics (p=0.03, Spearman's rho=0.33) and a significant positive association between AKI and the use of tobramycin cement (p=0.01, Spearman's rho=0.38). Factors that were not significantly associated with AKI include presence of preexisting hypertension (p = 0.26), hyperlipidemia (p = 0.83), coronary artery disease (p = 0.86), chronic kidney disease (p=0.56), and smoking status (p=.35). There was a trend towards increased risk of AKI in patients with diabetes mellitus (p= 0.12), however this was not significant. CONCLUSION. In single staged revision knee arthroplasty there is a significant association between acute kidney injury and type of oral/intravenous antibiotic used in the treatment. Both the use of intravenous vancomycin and tobramycin cement are independently associated with higher rates of AKI. Preexisting medical comorbidities are not independent risk factors for development of AKI. Serum creatinine and measurement of serum aminoglycoside and vancomycin levels should be performed after placement of an aminoglycoside-containing antibiotic cement spacer in a staged revision arthroplasty

We report the five- to-ten year results of Anderson Orthopaedic Research Institute type-2 bone defects treated with modular metal augments in revision knee surgery. A total of 102 revision knee arthroplasties in patients with type-2 defects treated with augments and stems were prospectively studied. Seven patients (seven knees) had incomplete follow-up and 15 patients (16 knees) died with the arthroplasty in situ. The mean follow-up of the 79 remaining knees was 7 ± 2 years (5 to 11). The presence of non-progressive radiolucent lines around the augment in 14% of knees was not associated with poorer knee scores, the range of movement, survival of the component or the type of insert which was used (p > 0.05). The survival of the components was 92 ± 0.03% at 11 years (95% CI, 10.3 to 11.2). We recommend the use of modular augmentation devices to treat type-2 defects in revision knee surgery

Purpose of the study: We report an unusual complication of patella tendon rupture that occurred secondary to the use of static cement spacer blocks in a series of three patients undergoing staged revision total knee arthroplasty (TKA) for infection. Methods and results: 3 male patients developed patella tendon injury secondary to anterior subluxation of static cement spacer blocks used at the first of a two-stage revision procedure for infected TKA. Average patient age was 70 years. The interval between the 1st and the 2nd stages varied between 3.5 to 24 months. At the second stage, it was observed that the patella tendon was completely severed and irreparable in one case, whereas it was partially injured and repairable in the other two cases. In the case with irreparable tendon injury, stable joint reconstruction could not be achieved at the second stage and ultimately resulted in knee arthrodesis. In the other two cases, 2nd stage revision was performed using hinged revision knee components and the tendon injury was repaired and protected with a circlage wire. None of the patients were satisfied with their outcome at the final review. Conclusion: This is the first report in the literature reporting the complication of patella tendon rupture secondary to the use of static cement spacer blocks in staged revision knee arthroplasty. The injury can either be repairable or irreparable. The functional outcome and satisfaction is not good after the salvage procedures. Therefore, we recommend that these spacer blocks should not be used in revision knee arthroplasty

We reviewed the clinical and radiological outcome of 72 Co-ordinate prostheses (DePuy, Warsaw, Ind) used for revision knee arthroplasty performed by a single surgeon from May 1994 to December 1997. Twenty-three patients (25 knees) since died. Two were lost to follow-up. At a mean follow-up of 10 years (range 9–12years), 45 knees in 43 patients were available for review. There were 12 men and 31 women with a mean age of 71.34 years (range 43 to 87 years). The reason for revision was instability in 38 knees, infection in 5 knees and stiffness in 2 knees. There was a significant improvement in the SF-12 PCS and WOMAC pain and stiffness scores at the latest follow-up. Five of these knees had to have re-revision surgery. One patient had a re-revision for aseptic loosening, one patient for recurrent dislocation of patella. Three patients underwent repeat procedures for infection. Radiological evaluation using the Knee Society system revealed well-fixed components in 35 knees (77.78%). The radiolucencies of varying degrees were present in 10 knees (22.22%). Eight had non-progressive radiolu-cencies and did not show any evidence of loosening. 25 (55.5%) knees had halo sign (radiopaque line) present around the prosthesis (7 were femoral side, 4 were tibial side and 14 around both the prosthesis). Using Kaplan Meier method the cumulative survival rate was 88.87% at 12 years, removal of the prosthesis or re-revision were used as end points. An analysis of clinical and standard radiographic outcomes has revealed that the Co-ordinate revision knee system continues to function satisfactorily at a mean of 10 years

Introduction: Tibial augments are required to replace bone loss in the proximal tibia during revision total knee replacement and can be either a rectangular ‘block’ shape or an angled ‘wedge’ shape. Purpose of study: We have identified a high failure rate with the ‘wedge’ shape currently used in the Co-ordinate (DePuy) revision knee system. Methods: We report a series of revision total knee replacement procedures performed using the Co-ordinate system. All revision ‘angled’ tibial wedge implants were selected from our prospective database containing follow up records for knee replacements. Patients underwent clinical and radiological review at three months following the procedure, on the anniversary of surgery and then on a yearly basis. Those with fewer than 12 months follow-up were excluded. Results: Between December 1993 and February 2006, a total of 34 patients (19 female, 15 male) required revision knee arthroplasty with an ‘angled’ wedged tibial augment. Mean age at surgery was 59.3 years (range 46–93). Five cases were excluded due to absence of follow-up (four requiring further surgery for infection and one due to unrelated medical complications). Of the remaining 29 cases, 16 (55.2%) had no problems with the tibial implant, while 13 (44.8%) exhibited radiological changes on review. Tibial implant migration was seen in 5 cases (17.2%), all within three years of surgery. One of these has needed further revision surgery and the other four are expected to need revision in the future. Seven (24.1%) were found to have a tibial radiolucent zone, which was progressive in four cases. There was one case of stem dissociation. Conclusion: ‘Angled’ tibial wedge implants are associated with a high rate of implant migration and loosening, presumably due to the effect of shear forces. Use of these implants should be reserved for low demand patients

Introduction and Aims: To compare the results of patients treated with articulating versus static antibiotic-impregnated spacers for infected knee arthroplasty. Method: All patients undergoing two-stage revision knee arthroplasty for sepsis in the last five years were reviewed. Twenty-six patients had been treated with articulating spacers. This group was compared to 36 patients treated with static spacers. The articulating spacer technique had been adopted more recently than the static technique. Minimum follow-up was 12 months from second stage re-implantation (average 22 months articulating, 40 months static). Patients were compared in terms of the need for extensile exposures required for re-implantation, range of motion at most recent review, eradication of infection and augmentation required on revision implants. Results: In the articulating group, fewer extensile exposure methods were required at second-stage prosthesis re-implantation (19% vs 36%). No tibial tuberosity osteotomies have been required since using the articulating spacer. The articulating group demonstrated a significantly improved range of flexion compared to the static group (106 vs 97 degrees – p=0.045) and had fewer patients with significant loss of extension or quadriceps lag. Eradication of infection was improved in the articulating group (92% vs 82%) but at shorter average follow-up. The need for augments and stabilised prostheses at revision surgery as a measure of bone loss was no different between the groups but was related to the number of prior surgical procedures. Conclusion: Articulating cement spacers facilitate reimplantation surgery by maintaining tissue planes and joint mobility without compromising joint stability or eradication rate of infection. Patients demonstrate better range of motion and less complications related to the extensor mechanism with the articulated spacer

The battle of revision TKA is won or lost with safe, effective, and minimally bony-destructive implant removal, protecting all ligamentous stabilisers of the knee and, most importantly, the extensor mechanism. For exposure, incisions should be long and generous to allow adequate access. A standard medial parapatellar capsular arthrotomy is preferred. A synovectomy is performed followed by debridement of all scar tissue, especially in the medial and lateral gutters. All peripatellar scar tissue is excised followed by release of scar tissue within the patellar tendon, allowing for displacement or everting of the patella. As patellar tendon avulsion at any time of knee surgery yields disastrous results, the surgeon should be continuously evaluating the patellar tendon integrity, especially while displacing/everting the patella and bringing the knee into flexion. If displacement/eversion is difficult, consider rectis-snip, V-Y quadricepsplasty, or tibial tubercle osteotomy. The long-held requisite for patellar eversion prior to component removal is inaccurate. In most cases simple lateral patellar subluxation will provide adequate exposure.

If a modular tibial system is involved, removal of the tibial polyethylene will decompress the knee, allowing for easier access to patellar, femoral, and tibial components. For patellar component removal, first identify the border of the patella, then carefully clean and debride the interface, preferably with electrocautery. If the tibial component is cemented all-polyethylene, remove using an oscillating saw at the prosthetic-bone interface. Debride the remaining cement with hand tools, ultrasonic tools, or burrs. Remove the remaining peg using a low-speed burr. If the tibial component is metal-backed, then utilise a thin saw blade or reciprocating saw to negotiate the undersurface of the component between the pegs. If pegs are peripherally located, cut with a diamond disc circular cutting tool. Use a trephine to remove the pegs.

For femoral component removal, identify the prosthetic-bone/prosthetic-cement interface then remove soft tissue from the interface, preferably with electrocautery. Disrupt the interface around all aspects of the component, using any of following: Gigli saw for cementless components only, micro saw, standard oscillating saw, reciprocating saw, a series of thin osteotomes, or ultrasonic equipment. If the femoral component is stemmed, remove the component in two segments using an appropriate screwdriver to remove the screw locking the stem to the component. Remove the femoral component with a retrodriver or femoral component extractor. Debride cement with hand tools or burr, using care to avoid bone fracture. If a stem is present, then remove with the appropriate extraction device. If “mismatch” exists, where femoral (or likewise, tibial) boss is smaller in diameter than the stem, creating a cement block prohibiting stem removal, remove the cement with hand tools or burr. If the stem is cemented, use hand tools, ultrasonic tools, or a burr to debride the cement. Curette and clean the canals.

For tibial component removal, disrupt the prosthetic-cement/prosthetic-bone interface using an oscillating or reciprocating saw. Gently remove the tibial component with a retrodriver or tibial extractor. If stem extensions are utilised, disengage and debride all proximal cement prior to removing the stem. If stem is present, then remove stem with appropriate extraction device. If stem is grit-blasted and well-fixed, create 8mm burr holes 1.5 to 2.5cm distal to tibial tray on medial aspect and a small divot using burr, then drive implant proximally with Anspach punch. Alternatively, a tibial tubercle osteotomy may be performed. If the stem is cemented, use hand tools, ultrasonic tools or burr to debride cement.

INTRODUCTION. Conventional surgical exposures are usually inadequate for 2-stage revision knee replacement ofinfected implants. Reduced range of motion, extensor mechanism stiffness, peripatellar contracture and soft tissue scarring make patellar eversion difficult and forced eversion places the integrity of the extensor mechanism at risk. On the contrary, a wide exposure is fundamental to allow complete cement spacer removal, soft tissue balancing, management of bone loss and reimplantation without damaging periarticular soft tissues. OBJECTIVES. To compare the long-term clinical, functional and radiographic results and the reinfection rate of the quadriceps snip approach and the tibial tubercle osteotomy in 2-stage revision knee replacement performed for septic loosening of the primary implant. METHODS. In our department, 87 patients had a 2 stage revision knee replacement for septic loosening of the primary implant between 1996 and 2008. In all patients, first stage consisted of primary implant removal, extensive soft tissue debridement and positioning of a static antibiotic loaded cement spacer. The timing for reimplantation was decided basing on negative clinical and laboratory (ESR, CRP) signs and negative Leukoscan results. For reimplantation, a quadriceps snip was used in patients with an intraoperative flexion >90° (Group A) while a tibial tubercle osteotomy (Group B) was used in patients with an intraoperative flexion <90°. RESULTS. At observation point, 4 patients died for reasons unrelated to surgery, leaving 42 patients in Group A and 41 in Group B. We had a total amount of 10 recurrent infections (11%) after reimplantation, 7 patients in Group A and 3 patients in Group B (p<0.005). Patients with a reinfection in Group A were treated with a knee fusion in 4 cases, a rerevision in 2 cases and an amputation above the knee in 1 case, while all those with a reinfection in Group B had a knee fusion. According to HSS score, 11 patients were rated as Excelent/Good in Group A and 9 patients in Group B (p=n.s.). Three patients had a major complication in Group A and 0 patients in Group B (p=0.005). No differences were found between the two groups regarding range of motion and subjective satisfaction. CONCLUSION. Tibial tubercle osteotomy is a safe procedure to obtain a wide exposure in 2-stage revision knee replacement performed for septic loosening of the primary implant and it is effective in reducing reinfection rate without compromising clinical results and range of motion

Abstract

We report the results of revision total knee replacement (TKR) in 26 patients with major metaphyseal osteolytic defects using 29 trabecular metal cones in conjunction with a rotating hinged total knee prosthesis. The osteolytic defects were types II and III (A or B) according to the Anderson Orthopaedic Research Institute (AORI) classification. The mean age of the patients was 72 years (62 to 84) and there were 15 men and 11 women. In this series patients had undergone a mean of 2.34 previous total knee arthroplasties. The main objective was to restore anatomy along with stability and function of the knee joint to allow immediate full weight-bearing and active knee movement. Outcomes were measured using Knee Society scores, Oxford knee scores, range of movement of the knee and serial radiographs. Patients were followed for a mean of 36 months (24 to 49). The mean Oxford knee clinical scores improved from 12.83 (10 to 15) to 35.20 (32 to 38) (p < 0.001) and mean American Knee Society scores improved from 33.24 (13 to 36) to 81.12 (78 to 86) (p < 0.001). No radiolucent lines suggestive of loosening were seen around the trabecular metal cones, and by one year all the radiographs showed good osteo-integration. There was no evidence of any collapse or implant migration. Our early results confirm the findings of others that trabecular metal cones offer a useful way of managing severe bone loss in revision TKR.

Cite this article: Bone Joint J 2013;95-B:1069–74.

Aims

Revision total knee arthroplasty (rTKA) is a technically challenging and costly procedure. It is well-documented that primary TKA (pTKA) have better survivorship than rTKA; however, we were unable to identify any studies explicitly investigating previous rTKA as a risk factor for failure following rTKA. The purpose of this study is to compare the outcomes following rTKA between patients undergoing index rTKA and those who had been previously revised.

Introduction: Seven patients underwent successful revision total knee replacement for aseptic loosening. Bovine bone graft was used to reconstruct bony defects in all.

Materials and methods: This is a retrospective review. Between April 2000 and March 2003, bovine bone (Tutobone™, Wescott-Medical, UK) was used in 7 revision arthroplasty cases (4 right knees & 3 left). There were 5 males and 2 females. The average age was 70.4 years. All revisions were carried out for aseptic loosening of the prostheses associated with massive osteolysis and bone loss.

The bone defects on the tibia and femur were as follows: (Obtained from operative records. Classified according to Anderson Orthopaedic Research Institute classification)

The tibial defects were corrected by impaction grafting and femoral condyle defects were corrected by using bovine bone as bulk grafts. Semi-constrained constrained stemmed cemented modular knee prostheses (TC3, Depuy) were used in all. Clinical outcomes were recorded by the Oxford Knee Score. Serial radiographs were evaluated for graft density, integration, implant loosening, alignment and subsidence.

Results: At recent follow-up, radiographs showed good graft integration, no loosening, and no subsidence of the implant and good prostheses alignment. The average Oxford Knee Score was 20.4.

Conclusion & discussion: Bovine bone substitute is an alternative. The bone defects in these patients were successfully reconstructed with bovine bone. It is an osteo-conductive matrix with intact type-I collagen that provides mechanical stability. It is also cost effective.

Early results are encouraging but long-tem follow-up is needed.

Near 70% of failures of knee arthroplastys due to septic or aseptic mobilization are complicated because of massive loss of bone stock. In these cases surgeon have to perform a salvage procedure to restore legamentous balance, articular plane direction and axes of lower limb, finally to fill bone defects. Today intrinsic biomechanical stability of revision implant is entrust to sophisticated design and materials of custom made and modular implants. Endomedullary stem has to assolve specific functions: mechanical stability contrasting stress due to the boneloss, offering support for omoplastic or spongious bone innests in femoralor tibial defects. There are paucity of study in literature about dimension and morphology of endomedullary canal, probably because of variability between periostal andendostal anatomy in each patients, specially age related. This date has conditioned production of several number of revision stem size for all population. This anthropometric study verify presence of a particular regionin femoral and tibial endomidullar canal not dependent from sex, height, morphotype, important for a good press-fit of revision stem.

Morphological date of midfemoral and tibial geometry was assessed in 50 subjects using Axial Computerized Tomography. Eleven (22%) were in men, thirty nine (78%) were in woman, with avarage of 73 years old (from 57 to 85). Exclusion criteria were previous operation at the same limb, deformity, pathology of bone metabolism. The level of sections were at 20, 18, 16 and 12 centimiters from articular plane for femur and at 8, 10, 13, 16 cm for tibia. Preliminar Ct scan with hight resolution program with bone alghoritm was performed. Axial view of any section was visualized at real dimension and maximal and minimal diameter of sections e were measured in millimiters.

Areas of any section is different in each patient; this variability is greater near articular plane. Infact in our sample SD (Standard Deviation) of diameters of proximal femoral and distal tibialsections was lesser than SD of the other measurements. No difference of results about sex was noted. On base of these measuremts more proximal two femoral sections and two more distal tibial sections were considered to elaborate an ideal area for anchorage zone of anatomical revision stem. We subdivided all sample in five groups with homogeneous value of diameter in selected sections. For any groups tangent & #945; of an ideal trunk of cone including maximum and minimum value of diameter considered was computed, and the relative inclination angle. In our sample the greatest diameter in proximal femoral section was 20 mm and the lowest 10 mm; for tibial measuremnts the greatest value in distal tibial level was 18 mm and the lowest was 10 mm. Inclination angle was ever around 2° in all groups. Moreover we have calculated the presumable length of an ideal trunk of cone that includes the minimum and maximum value of femural and tibial diameter measured.

About 5% of knee arthroplastys is destinated to an unsuccessfull. In many cases loosing of bone stock is huge and localized near articular plane. Afterward it’s important to restore biomechanical stability through endomedullary stem of revision implant. There are not many reports about morphology and anatomical study of femoral and tibial endomedullary canal. Many authors focus the attention on bone density or functional axes of the lower limb. Some authors studied remodelling process age-related about periostal ad endostal bone; cortical area undergoing thinning specially over fourthy years old. Our sample had mean of 73 years old: remodelling process is almost complete and then it is a good referenceto extrapolate real data about endomedullary morphology and width. Variability of data in all population about diameter of endomedullarycanal is lesser near femoral and tibial istmo, in particular around 18–20 cm from articular plane for femur and at 13–16 cm for tibia In our opinion short stem can’t guarantee good press-fit because of extreme variability of diameters in the population near knee. This anthropometric study confirm presence of anatomical area of the midfemural and tibial canal with common geometric characteristic in allpatient; it can be used to realize an anatomical stem that guarantees a good contact bone/prosthesis and then an optimal bone integration. On base of our results it is possibile realize few revision stem because in all groups of patients studied at 18–20 cm from knee for femur and at 13–16 cm for tibia, angle of inclination was ever 2°.