Total Knee Arthroplasty in Patients Who Have Skeletal Dysplasia: A Center's Experience With a Mean 9-Year Follow-Up.

BACKGROUND: Total knee arthroplasty (TKA) in patients who have skeletal dysplasia (SD) is a technically challenging surgery due to deformity, joint contracture, and associated comorbidities. Patients presenting with this condition have traditionally been treated with conservative measures, leading to poor outcomes. The aim of this study was to follow-up on patients who had SD following TKA, specifically with regards to clinical outcomes. METHODS: A total of 31 knees (22 patients) with SD that had undergone TKA in our institution were included in our study. The mean follow-up from index surgery was 110.3 months (range: 20 to 291). The type of dysplasia, implant used, and clinical outcomes with patient-reported outcome measures are presented. RESULTS: There were 8 patients (36.3%) who had a diagnosis of achondroplasia, followed by multiple epiphyseal dysplasia (31.8%) and spondyloepiphyseal dysplasia (22.7%). There were 14 men and 8 women who had a mean age of 51 years (range: 28 to 73). Custom implants were required in 12 cases (38.7%), custom jigs were used in 6 cases (19.4%), and robotic-assisted surgery was used in 2 (6.5%) TKAs. Hinged prostheses were used in 17 cases (54.8%), posterior-stabilized in 9 (29.0%), and cruciate-retaining implants in 5 (16.1%). There was 1 patient who sustained an intraoperative medial tibial plateau fracture treated with concomitant open reduction and internal fixation. There was 1 revision that occurred during the follow-up period with a patella resurfacing for continued anterior knee pain. Postoperatively, Oxford Knee Scores improved on average by 12.2 points. The 10-year and 20-year all-cause revision-free survival was 96.8, respectively. CONCLUSIONS: Despite the technical challenges and complexity associated with this unique patient cohort, we demonstrated excellent implant survivorship and clinical outcomes post-TKA with mid-term to long-term follow-up of more than 20 years. We recommend preoperative cross-sectional imaging for precise planning and implant templating with multidisciplinary team decision-making. Despite our results, functional outcomes remain inferior to primary arthroplasty within the general population, although we still recommend this treatment modality to appropriately counseled patients. LEVEL OF EVIDENCE: III.

Antimicrobial prophylaxis with teicoplanin plus gentamicin in primary total joint arthroplasty.

Objectives: To compare prosthetic joint infection (PJI) and acute kidney injury (AKI) rates among cohorts before and after changing our hospital's antimicrobial prophylactic regimen from cefuroxime to teicoplanin plus gentamicin. Methods: We retrospectively studied all patients undergoing primary total joint arthroplasty at our hospital 18 months pre- and post-implementation of the change in practice. All deep infections identified during follow-up were assessed against the European Bone and Joint Infection Society (EBJIS) definitions for PJI. Survival analysis using Cox regression was employed to adjust for differences in baseline characteristics and compare the risk of PJI between the groups. AKIs were identified using pathology records and categorized according to the KDIGO (Kidney Disease - Improving Global Outcomes) criteria. AKI rates were calculated for the pre- and post-intervention periods. Results: Of 1994 evaluable patients, 1114 (55.9 %) received cefuroxime only (pre-intervention group) and 880 (44.1 %) patients received teicoplanin plus gentamicin (post-intervention group). The overall rate of PJI in our study was 1.50 % (30 of 1994), with a lower PJI rate in the post-intervention group (0.57 %; 5 of 880) compared with the pre-intervention group (2.24 %; 25 of 1114). A corresponding risk reduction for PJI of 75.2 % (95 % CI of 35.2-90.5; p=0.004) was seen in the post-intervention group, which was most pronounced for early-onset and delayed infections due to coagulase-negative staphylococci (CoNS) and cefuroxime-resistant Enterobacteriaceae. Significantly higher AKI rates were seen in the post-intervention group; however, 84 % of cases (32 of 38) were stage 1, and there were no differences in the rate of stage-2 or -3 AKI. Conclusions: Teicoplanin plus gentamicin was associated with a significant reduction in PJI rates compared with cefuroxime. Increases in stage-1 AKI were seen with teicoplanin plus gentamicin.

Frequent microbiological profile changes are seen in subsequent-revision hip and knee arthroplasty for prosthetic joint infection.

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery. Patients and methods: Consecutive patients were retrospectively identified from databases at two specialist orthopaedic centres in the United Kingdom between 2011 and 2019. Patient were included who had undergone repeat-revision total knee replacement (TKR) or total hip replacement (THR) for infection, following an initial failed revision for infection. Results: A total of 106 patients were identified. Of these patients, 74 underwent revision TKR and 32 underwent revision THR. The mean age at first revision was 67 years (SD 10). The Charlson comorbidity index was ≤ 2 for 31 patients, 3-4 for 57 patients, and ≥ 5 for 18 patients. All patients underwent at least two revisions, 73 patients received three, 47 patients received four, 31 patients received five, and 21 patients received at least six. After six revisions, 90 % of patients had different organisms cultured compared with the initial revision, and 53 % of organisms were multidrug resistant. The most frequent organisms at each revision were coagulase-negative Staphylococcus (36 %) and Staphylococcus aureus (19 %). Fungus was cultured from 3 % of revisions, and 21 % of infections were polymicrobial. Conclusion: Patients undergoing multiple revisions for PJI are highly likely to experience a change in organism, with 90 % of patients having a different organism cultured by their sixth revision. It is therefore important to administer empirical antibiotics at each subsequent revision, taking into account known drug resistance from previous cultures. Our results do not support the routine use of empirical antifungals.

The Outcomes of Hip and Knee Fungal Periprosthetic Joint Infections: A Retrospective Cohort Study.

BACKGROUND: Fungal infections are a rare cause of periprosthetic joint infection (PJI), identified in 1% of all of these cases. Outcomes are not well-established due to small cohort sizes in the published literature. The aims of this study were to establish the patient demographics and infection-free survival of patients presenting to 2 high-volume revision arthroplasty centers who had fungal infection of either a hip or knee arthroplasty. We sought to identify risk factors for poor outcomes. METHODS: A retrospective analysis was performed of patients at 2 high-volume revision arthroplasty centers who had confirmed fungal PJI of the total hip arthroplasty (THA) and total knee arthroplasty (TKA). Consecutive patients treated between 2010 and 2019 were included. Patient outcomes were classified as infection eradication or persistence. A total of 67 patients who had 69 fungal PJI cases were identified. There were 47 cases involving the knee and 22 of the hip. Mean age at presentation was 68 years (THA mean 67, range 46 to 86) (TKA mean 69, range, 45 to 88). A history of sinus or open wound was present in 60 cases (89%) (THA 21 cases, TKA 39 cases). The median number of operations prior to the procedure at which fungal PJI was identified was 4 (range, 0 to 9), THA 5 (range, 3 to 9), and TKA 3 (range, 0 to 9). RESULTS: At a mean follow-up 34 months (range, 2 to 121), remission rates were 11 of 24 (45%) and 22 of 45 (49%) for hip and knee, respectively. There were 7 TKA (16%) and 1 THA cases (4%) that failed treatment resulting in amputations. During the study period, 7 THA and 6 TKA patients had died. Two deaths were directly attributable to PJI. Patient outcome was not associated with the number of prior procedures, patient comorbidities, or organisms. CONCLUSION: Eradication of fungal PJI is achieved in less than half of patients, and outcomes are comparable for TKA and THA. The majority of patients who have fungal PJI present with an open wound or sinus. No factors were identified that increase the risk of persistent infection. Patients who have fungal PJI should be informed of the poor outcomes.

A comparison of the microbiology profile for periprosthetic joint infection of knee arthroplasty and lower-limb endoprostheses in tumour surgery.

Aims: this study compared the patient and microbiological profile of prosthetic joint infection (PJI) for patients treated with two-stage revision for knee arthroplasty with that of lower-limb endoprostheses for oncological resection. Patient and methods: a total of 118 patients were treated with two-stage revision surgery for infected knee arthroplasty and lower-limb endoprostheses between 1999 and 2019. A total of 74 patients had two-stage revision for PJI of knee arthroplasty, and 44 had two-stage revision of oncology knee endoprostheses. There were 68 men and 50 women. The mean ages of the arthroplasty and oncology cohorts were 70.2 years (range of 50-89) and 36.1 years (range of 12-78) respectively ( p < 0 .01). Patient host and extremity criteria were categorized according to the Musculoskeletal Infection Society (MSIS) host and extremity staging system. The patient microbiological culture, the incidence of polymicrobial infection, and multidrug resistance (MDR) were analysed and recorded. Results: polymicrobial infection was reported in 16 % (12 patients) of knee arthroplasty PJI cases and in 14.5 % (8 patients) of endoprostheses PJI cases ( p = 0 .783). There was a significantly higher incidence of MDR in endoprostheses PJI, isolated in 36.4 % of cultures, compared with knee arthroplasty PJI (17.2 %, p = 0 .01). Gram-positive organisms were isolated in more than 80 % of cultures from both cohorts. Coagulase-negative Staphylococcus (CoNS) was the most common Gram-positive organism, and Escherichia coli was the most common Gram-negative organism in both groups. According to the MSIS staging system, the host and extremity grades of the oncology PJI cohort were significantly worse than those for the arthroplasty PJI cohort ( p < 0 .05). Conclusion: empirical antibiotic prophylaxis against PJI in orthopaedic oncology is based upon PJI in arthroplasty, despite oncology patients presenting with worse host and extremity staging. CoNS was the most common infective organism in both groups; however, pathogens showing MDR were significantly more prevalent in oncological PJI of the knee. Therefore, empirical broad-spectrum treatment is recommended in oncological patients following revision surgery.

Modifiable risk factors for mortality in revision total hip arthroplasty for periprosthetic fracture.

AIMS: The aim of this study was to identify modifiable risk factors associated with mortality in patients requiring revision total hip arthroplasty (THA) for periprosthetic hip fracture. METHODS: The electronic records of consecutive patients undergoing revision THA for periprosthetic hip fracture between December 2011 and October 2018 were reviewed. The data which were collected included age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, the preoperative serum level of haemoglobin, time to surgery, operating time, blood transfusion, length of hospital stay, and postoperative surgical and medical complications. Univariate and multivariate logistic regression analyses were used to determine independent modifiable factors associated with mortality at 90 days and one year postoperatively. RESULTS: A total of 203 patients were identified. Their mean age was 78 years (44 to 100), and 108 (53%) were female. The median time to surgery was three days (interquartile range (IQR) 2 to 5). The mortality rate at one year was 13.8% (n = 28). The commonest surgical complication was dislocation (n = 22, 10.8%) and the commonest medical complication within 90 days of surgery was hospital-acquired pneumonia (n = 25, 12%). Multivariate analysis showed that the rate of mortality one year postoperatively was five-fold higher in patients who sustained a dislocation (odds ratio (OR) 5.03 (95% confidence interval (CI) 1.60 to 15.83); p = 0.006). The rate of mortality was also four-fold higher in patients who developed hospital-acquired pneumonia within 90 days postoperatively (OR 4.43 (95% CI 1.55 to 12.67); p = 0.005). There was no evidence that the time to surgery was a risk factor for death at one year. CONCLUSION: Dislocation and hospital-acquired pneumonia following revision THA for a periprosthetic fracture are potentially modifiable risk factors for mortality. This study suggests that surgeons should consider increasing constraint to reduce the risk of dislocation, and the early involvement of a multidisciplinary team to reduce the risk of hospital-acquired pneumonia. We found no evidence that the time to surgery affected mortality, which may allow time for medical optimization, surgical planning, and resource allocation. Cite this article: Bone Joint J 2020;102-B(5):580-585.

Compression feedback devices over estimate chest compression depth when performed on a bed.

INTRODUCTION: CPR feedback/prompt devices are being used increasingly to guide CPR performance in clinical practice. A potential limitation of these devices is that they may fail to measure the amount of mattress compression when CPR is performed on a bed. The aim of this study is to quantify the amount of mattress compression compared to chest compression using a commercially available compression sensor (Q-CPR, Laerdal, UK). A secondary aim was to evaluate if placing a backboard beneath the victim would alter the degree of mattress compression. METHODS: CPR was performed on a manikin on the floor and on a bed with a foam or inflatable mattress with and without a backboard. Chest and mattress compression depths were measured by an accelerometer placed on the manikin's chest (total compression depth) and sternal-spinal (chest) compression by manikin sensors. RESULTS: Feedback provided by the accelerometer device led to significant under compression of the chest when CPR was performed on a bed with a foam 26.2 (2.2)mm or inflatable mattress 32.2 (1.16)mm. The use of a narrow backboard increased chest compression depth by 1.9mm (95% CI 0.1-3.7mm; P=0.03) and wide backboard by 2.6mm (95% CI 0.9-4.5mm; P=0.013). Under compression occurred as the device failed to compensate for compression of the underlying mattress, which represented 35-40% of total compression depth. CONCLUSION: The use of CPR feedback devices that do not correct for compression of an underlying mattress may lead to significant under compression of the chest during CPR.