Outcomes of Debridement, Antibiotics and Implant Retention (DAIR) for Periprosthetic Joint Infection in a High-Volume Arthroplasty Centre.

Purpose: Prosthetic joint infection (PJI) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) can be a devastating diagnosis. Debridement, antibiotics and implant retention (DAIR) is a preferred treatment modality for acute PJI. A retrospective analysis of infected primary arthroplasties to evaluate the success of DAIR and factors influencing its outcomes. Methods: We retrospectively reviewed all patients who underwent DAIR for PJI at our unit between 2010 and 2018. Patients who underwent revision surgery as an index procedure, arthroscopic washout and those with less than two years of follow-up were excluded. Treatment failure was defined as revision arthroplasty for recurrence of infection within 2 years of the index procedure. Chi-square and Fischer's exact test were used to compare between patient factors and DAIR outcomes. Kaplan-Meier survival curve and log-rank test were used to analyse implant survivorship following DAIR. Results: Of the sixty patients (40 knees, 20 hips) who underwent DAIR, eighteen (13 knees, 5 hips) required revision arthroplasty within 2 years accounting for a success rate of 70%. Predictive factors for revision were American Society of Anaesthesiologist (ASA) score of greater than 2 (p = 0.021), BMI > 35 (p = 0.046), C Reactive protein (CRP) > 200 mg/L (p = 0.007) and Staphylococcus aureus growth (p = 0.012). The five-year survival rate for DAIR was 70%, which remained constant after two years from DAIR. Conclusion: Success rate of DAIR in PJI was 70% which was comparable to similar studies in the literature. ASA > 2, BMI > 35, CRP > 200 and staphylococcus aureus growth were predictors for DAIR failure. Implant survival rate and duration were better following DAIR in early-onset PJI.

Diagnosis and management of the infected total knee replacement: a practical surgical guide.

PURPOSE: Prosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a significant burden in health care. Diagnosis and proper management are challenging. A standardised procedure for the diagnostic workup and surgical management provides clear benefits in outcome. METHODS: Several diagnostic protocols and definitions for PJI were established in recent years. Proper PJI diagnosis remains critical for success and for choosing the optimal treatment option. A distinct workup of diagnostic steps, the evaluation of the results in a multidisciplinary setup and the meticulous surgical management of the infection are the key factors of successful treatment. RESULTS: The management of PJI after TKA consists of early revision with debridement and implant retention (DAIR) in early cases or staged revision in late infections beyond 30 days postoperative or after onset of acute symptoms. The revision is performed as a two-stage procedure with the use of a fixed or mobile antibiotic spacer, or in selected cases as a single-stage operation with the use of local and systemic antibiotic treatment. CONCLUSIONS: This paper reflects the opinion of two revision surgeons who follow the same protocol for diagnosis and treatment of PJI after TKA, highlighting the key steps in diagnosis and management. LEVEL OF EVIDENCE: Expert's opinion.

Fulfilment of preoperative expectations and postoperative patient satisfaction after total knee replacement. A prospective analysis of 200 patients.

BACKGROUND: In total knee arthroplasty (TKA), the association between preoperative patient expectations, their postoperative fulfilment, and satisfaction is not well understood. The aim of this study was to quantify these relationships in a cohort of TKA patients with differing socio-economic backgrounds from across Scotland. METHODS: Expectations of 200 patients undergoing TKA were assessed using the Hospital for Special Surgery Knee Replacement Expectation Score. Postoperatively, expectation fulfilment was assessed at six weeks and one year. Satisfaction was measured using a five-point Likert scale. Preoperative and postoperative scores were compared across satisfaction groups. Relationships between individual and overall expectation fulfilment, satisfaction, and demographics were analysed. RESULTS: At six weeks, 30% of expectations were fulfilled, increasing to 48% at one year. Corresponding satisfaction rates were 84% and 89%. Higher fulfilment scores were associated with greater satisfaction. Fulfilment of pain and mobility expectations were most predictive of satisfaction. Expectations of kneeling, squatting, paid work and sexual function went unfulfilled. Preoperative expectations were not related to postoperative satisfaction. Males had higher postoperative fulfilment scores. CONCLUSIONS: This study showed a clear association between fulfilment of preoperative expectations and patient satisfaction following TKA. However, less than 50% of patient expectations were completely fulfilled. While higher fulfilment scores were predictive of greater satisfaction, low overall fulfilment score did not preclude satisfaction. The high correlation of pain and function expectation fulfilment with satisfaction emphasises the need to relate these as appropriate preoperative expectations, while awareness of unfulfilled expectations may allow engagement with and resolution of ongoing concerns and disappointments.

Clostridium septicum arthroplasty infection: beware of occult aortitis and malignancy.

INTRODUCTION: The Clostridia species are responsible for life-threatening conditions such as tetanus, botulism and gas gangrene. Clostridium septicum is a rare cause of clinical infection, accounting for less than 1% of blood culture samples that test positive for Clostridia. However, C. septicum bacteraemia is associated with greater than 60% mortality and in over 80% of cases is associated with an underlying malignancy. CASE PRESENTATION: We present a review of the literature and the first case of an acute arthroplasty infection and concurrent infective aortitis caused by this organism in the absence of an identified underlying malignancy. Early diagnosis and multi-disciplinary input resulted in the patient surviving a rare and potentially fatal infective aortitis and septic arthritis. CONCLUSION: This case demonstrates the importance of early systemic investigation to exclude occult infective aortitis in C. septicum infection. The key role of multi-disciplinary input into the management of this often fatal infection is also discussed along with the requirement to exclude occult gastrointestinal and haematological malignancy.

What Do Scottish Patients Expect of Their Total Knee Arthroplasty?

BACKGROUND: The aim of this study was to carry out an in-depth assessment of patient expectations before surgery in a representative sample of the Scottish population undergoing primary total knee arthroplasty and also assess the influence of demographic factors and preoperative functions on expectations. METHODS: This was a prospective cohort study of 200 patients treated in our institution from November 2011 to July 2013. Patients received standard preoperative preparation including consultation with a surgeon, an information booklet and a DVD. Patients completed the Hospital for Special Surgery Knee Replacement Expectation Survey along with the EuroQol EQ-5D-3L health questionnaire on the day of admission. RESULTS: Fifty-nine percent of the cohort were women, mean age 67.7 years (45-84 years), mean body mass index 32.5 (21-50), mean preoperative Oxford Knee Score 17 (1-44). Relief of pain and improved ability to walk were the most important expectations, followed by the ability to use public transport and/or drive, ability to change position, ability to walk down stairs, and the ability to carry out routine daily activities and/or chores. Some expectations were unrealistic. No relationships between expectations and demographics, including preoperative function, were found. CONCLUSION: This study suggests that patients have very high and sometimes unrealistic expectations regarding their improvements after total knee arthroplasty even after detailed preoperative consultation and education. In addition, these expectations cover a wide range of dimensions. We suggest that to effectively manage patients' expectations, it is important to assess each patient individually and reinforce what expectations can realistically be achieved.

Spontaneous resolution of superior medial geniculate artery pseudoaneurysm following total knee arthroplasty.

Vascular injury after total knee arthroplasty is a rare event with significant morbidity. To date there are a handful of cases of pseudoaneurysms affecting the popliteal artery and cases involving one of the geniculate arteries are even rarer. Most case reports involving injuries to the geniculate vessels have reported surgical intervention to treat the condition. We report a case where injury to the superior medial geniculate artery with formation of pseudoaneurysm resolved without any surgical intervention.

A comparison of variable angle versus fixed angle distal femoral resection in primary total knee arthroplasty.

This study assessed whether using a variable distal valgus resection angle improved post-operative coronal lower limb alignment in total knee arthroplasty (TKA). Two groups were compared: Fixed (n = 124), where a fixed distal valgus resection angle of 7° was used; Variable (n = 87), where the resection angle was adjusted to the measured femoral mechanical anatomical (FMA) angle of the patient. FMA and mechanical femoro-tibial (MFT) angles were measured on pre-operative and post-operative hip-knee-ankle radiographs. 85% of patients in the Variable group had a post-operative MFT angle within 0° ± 3°compared to 69% in the Fixed group (P = 0.006). The use of a fixed distal femoral resection angle for all patients is not appropriate. Setting the resection to an individual patient's FMA angle can significantly improve the post-operative MFT angle.

Two-year radiologic assessment of the Trident Peripheral Self-Locking cup using EBRA.

UNLABELLED: We performed a radiologic assessment of the Trident Peripheral Self-Locking cup 2 years after implantation to assess early migration behaviour and to establish if incomplete postoperative seating correlated with early instability. A retrospective analysis of 30 cases was performed using EBRA. No cups had acetabular screws. Average total migration was 1.5 mm (range 0.1 to 5.9 mm). Seventeen showed total migration >1 mm and 7 of these showed further migration >2 mm (range 2.3 to 5.9 mm). Twenty cups demonstrated incomplete seating on initial post-operative radiographs (mean 1.4 mm, range 0.3 to 3.0). No relationship between incomplete seating and migration was identified (p = 0.86). The majority of gaps consolidated at differing times within the 2 year period. Oxford Hip scores showed significant improvement after surgery (p = 0.001) and this was independent of migration (p = 0.76). At 5 years there were no revisions for aseptic loosening. CONCLUSION: The majority of the cups demonstrated early radiographic instability, and this was not related to incomplete seating. Five year functional outcome appears good and independent of migration and initial seating.

Blood loss following total knee replacement is reduced when using computer-assisted versus standard methods.

Perioperative blood loss was compared in 136 patients (2 groups of 68 patients) who underwent total knee arthroplasty (TKA). Blood loss was significantly lower when using a computer-navigated technique in comparison to a method employing intramedullary femoral rods. Total blood loss was calculated from body weight, height and haematocrit change, using a model that has been shown to reliably estimate true blood loss. Average total blood loss was 1362 ml in the standard TKA group, and 1137 ml in the computer navigated TKA group. This difference was statistically significant (p = 0.016). This study, as compared to previous papers assessing the effects of navigation, used a larger sample size and a more reliable method of assessing blood loss, which takes account of "hidden" losses, and confirms their findings.

Natural distribution of the femoral mechanical-anatomical angle in an osteoarthritic population and its relevance to total knee arthroplasty.

A common surgical goal in TKA is to restore neutral alignment of the lower limb by making bone cuts perpendicular to the mechanical axes of the femur and tibia. Standard practice for many surgeons is to use the same distal femoral valgus resection angle for all patients, assuming little or no variation in the femoral mechanical-anatomical (FMA) angle between different patients' knees. This study analysed 174 pre-operative hip-knee-ankle radiographs of osteoarthritic knees (157 patients, 87 female and 70 male, mean age 70years and mean BMI 31.8). Measurements of mechanical femorotibial (MFT) and FMA angles were made. The mean FMA angle was 5.7° (SD 1.2°, range 2° to 9°). There was a statistically significant difference between the FMA angle for males and females with males tending to have larger FMA angles (p<0.001). There was a statistically significant correlation between MFT and FMA angle (r=-0.499) with varus knees tending to have larger FMA angles (p<0.001). These results indicate a wide distribution of FMA angle in an osteoarthritic population. In terms of achieving appropriate coronal alignment in TKA the use of a fixed valgus resection angle is not suitable for all patients and it may be preferable to adjust the distal femoral cut according to individual FMA angles. However if this angle is not available the cut may be adjusted according to pre-operative coronal alignment, using 6° for neutral/mild varus, >6° for more severe varus and <6° for valgus knees.

Femoral nerve block for total knee replacement - a word of caution.

Femoral nerve block (FNB) is a well documented option for post-operative analgesia following major knee surgery. However, motor blockade may be prolonged preventing early mobilisation thereby increasing the length of stay. In addition, as a consequence of persistent quadriceps weakness, patients have an increased risk of falling. We present a series of five patients who underwent total knee replacement with spinal anaesthesia and FNB who fell, sustaining complete wound disruption - including a patient with peri-prosthetic fracture requiring further surgery and prolonged hospital stay. The literature, which is largely in anaesthetic journals, reflects the high quality of analgesia of FNB but makes little or no mention of the delays or dangers in early mobilization. We believe that the potential risks to orthopaedic patients are underestimated.