Septic Arthritis After Anterior Cruciate Ligament Reconstruction: How Important Is Graft Salvage?

Independent Risk Factors Associated With Venous Thromboembolism After Knee Arthroscopy: A Retrospective Study of 222 Patients

Background

A serious complication after knee arthroscopy is venous thromboembolism (VTE), which includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). However, asymptomatic VTE is frequently undetected.

Purpose

To (1) report the incidence of VTE after knee arthroscopy using ultrasound examination and computed tomography pulmonary angiography (CTPA) and (2) discover the independent risk factors of VTE after knee arthroscopy and determine the corresponding cutoff values of these indicators.

Study Design

Case-control study; Level of evidence, 3.

Methods

Included were 222 patients (115 male) who underwent arthroscopic knee procedures between October 2022 and January 2023. Baseline characteristics, blood test results, and VTE assessments were collected. During the 2-week follow-up, routine lower extremity vascular ultrasound was applied for DVT measurement, with CTPA evaluation for suspected PE. Patients were allocated into VTE and no-VTE groups, and descriptive statistics were used to analyze baseline data. Logistic regression analysis was used to determine the correlation between binary variables and the presence of postoperative VTE. Multivariate logistic regression analysis was further performed to determine the independent risk factors of VTE.

Results

Of the 222 patients, 37 (16.7%) had DVT and 1 (0.5%) had both DVT and PE. Compared to the no-VTE group, the VTE group was significantly older, with more female patients; higher body mass index (BMI) and postoperative D-dimer level; and higher rates of hypertension, hyperlipidemia, varicose veins of the lower extremity, and abnormal postoperative fibrin degradation product level (P≤ .043 for all). Notably, operative time >20 minutes was not significantly associated with postoperative VTE (P = .513). The independent risk factors for VTE included age >32 years (odds ratio [OR], 20.71 [95% CI, 4.40-97.47]; P < .001), BMI >23 kg/m2 (OR, 3.52 [95% CI, 1.11-11.14]; P = .032), hyperlipidemia (OR, 6.81 [95% CI, 1.86-24.88]; P = .004), and postoperative D-dimer level >0.63 mg/L (OR, 34.01 [95% CI, 7.36-157.07]; P < .001).

Conclusion

The incidence of VTE after knee arthroscopy was 16.7% at the 2-week follow-up. Age >32 years, BMI >23 kg/m2, hyperlipidemia, and postoperative D-dimer >0.63 mg/L were independent risk factors of postoperative VTE within 2 weeks after knee arthroscopy. For patients with knee arthroscopy, the cutoff value of postoperative D-dimer for VTE was found to be 0.63 mg/L for timely intervention.

Poorer patient-reported outcome and increased risk of revision at a 5-year follow-up among patients with septic arthritis following anterior cruciate ligament reconstruction: a register-based cohort study of 23,075 primary anterior cruciate ligament reconstructions

PURPOSE

The primary aim of this study is to analyse the patient-reported outcomes after ACLR complicated by septic arthritis. The secondary aim is to examine the 5-year risk of revision surgery after primary ACLR complicated by septic arthritis. The hypothesis was that patients with septic arthritis after ACLR are more likely to have lower PROMs scores and an increased risk of revision, compared with patients without septic arthritis.

MATERIALS AND METHODS

All primary ACLRs, with a hamstring or patellar tendon autograft (n = 23,075), in the Swedish Knee Ligament Register (SKLR) between 2006 and 2013 were linked with data from the Swedish National Board of Health and Welfare to identify patients with postoperative septic arthritis. These patients were verified in a nationwide medical records analysis and compared with patients without infection in the SKLR. The patient-reported outcome was measured using the Knee injury and Osteoarthritis Index Score (KOOS) and the European Quality of Life Five Dimensions Index (EQ-5D) at 1, 2 and 5 years postoperatively and the 5-year risk of revision surgery was calculated.

RESULTS

There were 268 events of septic arthritis (1.2%). The mean scores on the KOOS and EQ-5D index were significantly lower for patients with septic arthritis on all subscales on all follow-up occasions compared with patients without septic arthritis. Patients with septic arthritis had a revision rate of 8.2% compared with 4.2% in patients without septic arthritis (adjusted hazard ratio 2.04; confidence interval 1.34-3.12).

CONCLUSION

Patients suffering from septic arthritis following ACLR are associated with poorer patient-reported outcomes at 1-, 2- and 5-year follow-ups compared with patients without septic arthritis. The risk of revision ACL reconstruction within 5 years of the primary operation for patients with septic arthritis following ACLR is almost twice as high, compared with patients without septic arthritis.

LEVEL OF EVIDENCE

III.

ESSKA and EBJIS recommendations for the management of infections after anterior cruciate ligament reconstruction (ACL-R): prevention, surgical treatment and rehabilitation

PURPOSE

Infection after anterior cruciate ligament reconstruction (ACL-R) is a rare but severe complication. Despite an increase in articles published on this topic over the last decade, solid data to optimized diagnostic and therapeutic measures are scarce. For this reason, the European Bone and Joint Infection Society (EBJIS) and the European Society for Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) collaborated in order to develop recommendations for the diagnosis and management of infections after ACL-R. The aim of the workgroup was to perform a review of the literature and provide practical guidance to healthcare professionals involved in the management of infections after ACL-R.

METHODS

An international workgroup was recruited to provide recommendations for predefined clinical dilemmas regarding the management of infections after ACL-R. MEDLINE, EMBASE, Cochrane Library and Scopus databases were searched for evidence to support the recommended answers to each dilemma.

RESULTS

The recommendations were divided into two articles. The first covers etiology, prevention, diagnosis and antimicrobial treatment of septic arthritis following ACL-R and is primarily aimed at infectious disease specialists. This article includes the second part of the recommendations and covers prevention of infections after ACL-R, surgical treatment of septic arthritis following ACL-R and subsequent postoperative rehabilitation. It is aimed not only at orthopedic surgeons, but at all healthcare professionals dealing with patients suffering from infections after ACL-R.

CONCLUSION

These recommendations guide clinicians in achieving timely and accurate diagnosis as well as providing optimal management, both of which are paramount to prevent loss of function and other devastating sequelae of infection in the knee joint.

LEVEL OF EVIDENCE

V.

Deep Infection After Anterior Cruciate Ligament Reconstruction Diagnosed by Intratunnel Suspensory Fixation Device Migration: A Case Report

CASE

A 43-year-old woman sustained an anterior cruciate ligament injury while kickboxing and underwent anterior cruciate ligament reconstruction with hamstring autograft with suspensory fixation. Lateral thigh wound was superficially infected at 2 weeks postoperatively with resolution of signs and symptoms after debridement. Three months later, posterolateral knee pain developed and radiographs revealed intratunnel migration of the device. That observation with abnormal magnetic resonance imaging and serology results led to the diagnosis of deep infection. Immediate device removal and debridement were performed. Consequently, the grafts were preserved, and the patient could perform kickboxing 2 years thereafter.

CONCLUSIONS

Intratunnel migration of suspensory fixation devices can support a diagnosis of infection.

Management of ACL Reconstruction Complicated by MRSA Osteomyelitis Requiring a Gastrocnemius Perforator Flap: A Case Report

CASE

A 21-year-old woman presented with sepsis from methicillin-resistant Staphylococcus aureus, patellar osteomyelitis, and 6 × 4 × 2-cm proximal anteromedial soft-tissue defect 1 week after bone-tendon-bone autograft anterior cruciate ligament reconstruction (ACL-R). She underwent multiple irrigation and debridement (I&Ds), hardware removal, bone grafting with antibiotic-loaded tricalcium phosphate beads, and medial gastrocnemius perforator flap with plastic surgery. At 18 months after her initial ACL-R, single-stage revision ACL-R with quadriceps autograft was performed.

CONCLUSION

When acute ACL-R infection does not respond to initial I&D and Intravenous (IV) antibiotics, retained hardware and graft tissue must be removed expeditiously to prevent sepsis, osteomyelitis, and soft-tissue defects.

Vancomycin presoak reduces infection in anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

To compare the effect of vancomycin presoak treatment of grafts during anterior cruciate ligament reconstruction on the incidence of postoperative infection or septic arthritis.

METHODS

Studies published before May 3, 2022 investigating vancomycin presoak of grafts during anterior cruciate ligament reconstruction were searched in the PubMed and Cochrane Central Register of Controlled Trials. Studies were screened, and data on the incidence of postoperative infection or septic arthritis were extracted and included in the analysis.

RESULTS

Thirteen studies were included for analysis after search screening, yielding a total of 31,150 participants for analysis, of whom 11,437 received graft vancomycin presoak treatment, and 19,713 did not receive treatment. Participants who received vancomycin treatment had significantly lower infection rates (0.09% versus 0.74%; OR 0.17; 95% CI 0.10, 0.30; P < 0.00001).

CONCLUSION

Pre-soaking of the graft with vancomycin during ACL reconstruction reduced the incidence of postoperative infection and septic arthritis.

Septic Arthritis Complicating Arthroscopic Anterior Cruciate Ligament Reconstruction: An Experience from a Tertiary-Care Hospital

Background

Septic arthritis (SA) of the knee following anterior cruciate ligament reconstruction (ACLR) is considered a catastrophic complication in terms of reduced or loss function of the involved joint. The aims of this study were to gauge the incidence, risk factors, and causative organisms of SA after ACLR.

Methods

We conducted a retrospective review of 836 patients who underwent primary ACLR at our institution from October 2018 to September 2021. Patients’ demographics, onset of presentation, clinical symptoms, laboratory findings, and management details were obtained from patients’ electronic medical records.

Results

Out of the 836 primary ACLRs, 12 were complicated with SA (1.43%). Independent risk factors associated with SA included age (OR; 11.12, 95% CI; 1.3–94.97), obesity (OR; 8.51, 95% CI; 1.02–71.13), and diabetes mellitus (OR; 12.58, 95% CI; 2.39–66.3). Staphylococcus aureus was the most frequent culprit organism (66.7%), followed by Streptococcus species (25%), and Pseudomonas aeruginosa (8.3%). No fungal, mycobacterial, or polymicrobial growth were recovered from synovial fluid cultures. All of the infected cases underwent arthroscopic joint lavage and debridement in the operating room followed by intravenous antibiotics. Graft removal was not done in any of the involved patients, with eradication of infection in all cases.

Conclusion

SA after ACLR is uncommon, with S. aureus identified in about two-thirds of the patients. Prompt diagnosis and treatment are crucial to avoid graft loss and arthritis-associated joint damage. Orthopedic surgeons should consider rigorous implementation of infection control strategies to minimize the incidence of this devastating morbidity.

Allograft contamination during suture preparation for anterior cruciate ligament reconstruction: an ex vivo study

PURPOSE

Effects of suture preparation on graft contamination remain unknown in anterior cruciate ligament reconstruction (ACLR). This study aimed to evaluate the incidence of allograft contamination at different time points of graft preparation and investigate differences in contamination between different sites of the allografts.

METHODS

Fourteen hamstring tendon (HT), 9 quadriceps tendon (QT), and 9 bone-patellar tendon-bone (BTB) allografts were harvested, sterilised, and stored following routine procedures. Graft suture preparation was performed with baseball stitching for soft tissue and bone drilling for bone plug. The time was recorded simultaneously. The graft was kept moist in a standard operating room environment for 30 min after the initiation of preparation. The specimens were obtained from the middle and both ends of each graft for culture at three different time points: pre-suturing, post-suturing, and 30 min after the initiation of preparation. A total of 192 specimens were transferred to the microbiology laboratory for culture, identification, and semi-quantitative assessment. Culture results were classified as negative, poor, and abundant based on the extent of growth. Contamination level was recorded as low or high corresponding to culture results of poor or abundant.

RESULTS

The duration of suture preparation was 348, 301, and 246 s for HT, QT, and BTB (P = 0.090). The specimens had a positive culture rate of 41/192 (21.4%), of which 21 were from the ends and 20 from the middle. More positive samples with abundant bacterial growth were detected from the ends than from the middles post-suturing (7/8 vs. 1/7, P = 0.010) and at 30 min (6/11 vs. 0/11, P = 0.012). The total graft contamination rate was significantly higher at 30 min (19/32, 59.4%) than pre-suturing (4/32, 15.6%) and post-suturing (9/32, 28.1%) (P < 0.001). The contamination rate with abundant bacterial growth was higher post-suturing (7/32, 21.9%) than pre-suturing (0%). No statistically significant differences were found among the three types of allografts.

CONCLUSION

The contamination rate increases significantly at 30 min compared with pre-suturing and post-suturing. Suture preparation may have introduced the high-level contamination, to which the ends of the graft were more prone than the middle. Therefore, routine prophylactic decontamination after suture preparation should be considered, especially for the ends of the grafts.

Evaluation of Experimental and Clinical Efficacy on Surgical Debridement and Systemic Antibiotics Treatment for Early Knee Infection after Anterior Cruciate Ligament Reconstruction

Deep knee infection (DKI) after anterior cruciate ligament reconstruction (ACLR) is rare and challenging. The optimal treatment strategy for infection after ACLR remains controversial. This study aimed to investigate the optimal treatment for early infection after ACLR surgery. Rats with unilateral ACLR were injected with 3.0 × 10⁵ colony forming units (CFU) of Staphylococcus aureus in the knee joint for 7 days. Next, with surgical debridement (SD) and/or 21 days of antimicrobial (systemic vancomycin and oral rifampicin [SVR]) therapy, rats were euthanatized and samples harvested. We evaluated signs of infection by general postoperative conditions, serum inflammatory markers, microbiological counting, knee radiographs, micro-computed tomography (micro-CT), histologic staining, and scanning electron microscopy (SEM). Clinically, the data from 12 patients who suffered from DKI after ACLR were analyzed retrospectively. The DKI rats treated with SVR showed better outcomes in general postoperative conditions, serum inflammatory markers, microbiological counting, biofilm on the interference screw and graft, radiographic signs of periarticular osseous destruction, and inflammatory reaction in the joint tissues than those with SD treatment, while the DKI rats with SD and SVR administration showed the best outcomes. Rats which received SD and SVR administration had their S. aureus contamination completely eradicated. All patients treated with SD & SVR or SVR alone had effectively controlled knee infections and achieved good knee function outcomes in the 6 months after treatment, but one patient developed more serious knee infections. Therefore, surgical debridement combined with systemic antibiotics treatment could effectively eliminate S. aureus contamination in the DKI rat model and in patients after ACLR without affecting knee function. Treatment with systemic antibiotics could also control early DKI, which would be especially applicable in patients who could not tolerate surgery.

Postoperative Infection: Prevention, Diagnosis, and Treatment Guidelines for the Sports Surgeon

Postoperative infection remains a potentially devastating complication facing the sports medicine surgeon. Infection prevention begins with a thorough history and physical examination to identify patient specific risk factors and aid in risk stratification. Perioperative steroid injections should be used cautiously, with increased time prior to or following surgery being associated with lower infection risk. Sterile preparation with an alcohol containing solution is typically preferred, though there is limited evidence to identify which product is superior. Diagnosis can be challenging with a high index of suspicion needed to identify and appropriately manage patients. Treatment involves prompt irrigation and debridement with deep cultures. Antibiotic coverage should begin with empiric broad treatment and be tailored based on culture results. Early consultation with an infectious disease specialist is recommended to ensure appropriate antibiotic coverage and duration of treatment.

Patients return to sports and to work after successful treatment of septic arthritis following anterior cruciate ligament reconstruction

PURPOSE

To determine specific return to sports (RTS) and return to work (RTW) rates of patients with septic arthritis following anterior cruciate ligament reconstruction (ACLR), and to assess for factors associated with a diminished postoperative return to physical activity after successful eradication of the infection.

METHODS

In this study, patients who were treated for postoperative septic arthritis of the knee following anterior cruciate ligament reconstruction between 2006 and 2018 were evaluated at a minimum follow-up (FU) of 2 years. Patients' outcomes were retrospectively analyzed using standardized patient-reported outcome scores including the Lysholm score and the subjective IKDC score, as well as return to sports and return to work questionnaires to assess for the types, number, and frequency of sports performed pre- and postoperatively and to evaluate for potential occupational changes due to septic arthritis following ACLR. To assess for the signifiance of the graft at follow-up, outcomes were compared between patients with a functioning graft at FU and those without, as well as between patients with initial graft retention and those with graft removal and consecutive revision ACLR.

RESULTS

Out of 44 patients eligible for inclusion, 38 (86%) patients at a mean age of 36.2 ± 10.3 years were enrolled in this study. At a mean follow-up of 60.3 ± 39.9 months, the Lysholm score and the subjective IKDC score reached 80.0 ± 15.1 and 78.2 ± 16.6 points, respectively. The presence of a graft at FU yielded statistically superior results only on the IKDC score (p = 0.014). There were no statistically significant differences on the Lysholm score (n.s.) or on the IKDC score (n.s.) between patients with initial graft retention and those with initial removal who had undergone revision ACLR. All of the included 38 patients were able to return to sports at a median time of 8 (6-16) months after their last surgical intervention. Among patients who performed pivoting sports prior to their injury, 23 (62.2%) returned to at least one pivoting sport postoperatively. Overall, ten patients (26.3%) returned to all their previous sports at their previous frequency. The presence of a graft at FU resulted in a significantly higher RTS rate (p = 0.010). Comparing patients with initial graft retention and those with graft removal and consecutive revision ACLR, there was no statistically significant difference concerning the RTS rate (n.s.). Thirty-one patients (83.8%) were able to return to their previous work.

CONCLUSION

Successful eradication of septic arthritis following anterior cruciate ligament reconstruction allows for a postoperative return to sports and a return to work particularly among patients with ACL-sufficient knees. However, the patients' expectations should be managed carefully, as overall return rates at the pre-injury frequency are relatively low.

LEVEL OF EVIDENCE

IV.

[Options and limits of arthroscopic treatment of joint empyema]

Due to its low invasive nature, arthroscopy nowadays represents the gold standard in the treatment of native joint empyema. This article gives a summary of the literature with expert recommendations, reviews and case reports on arthroscopic treatment of native joint empyema and the limitations. Most cases of native joint empyema can be successfully cleansed with arthroscopic treatment alone including lavage and débridement. In advanced stages of infection open arthrotomy is often needed for final infection cleansing. In postoperative infections with enclosed foreign material, such as after cruciate ligament reconstruction, the foreign material can in most cases be left in and successful infection eradication can be carried out with several arthroscopic lavages and débridement. In cases of higher grade infections with destruction of the joint, arthroscopic treatment alone is normally insufficient.

Anterior Cruciate Ligament Injury: Conservative Versus Surgical Treatment

The most frequent type of ligament injury is an anterior cruciate ligament (ACL). The mechanisms of an ACL injury are classified as direct contact, indirect contact, and non-contact. Physical examination for the assessment of the ACL is commonly used in routine care in the evaluation of the knee and is part of the diagnostic process. Due to the high degree of variability in their presentation and outcomes, treatment must be tailored according to factors such as patient demographics, the severity of the damage, and long-term improvement profile. When it comes to ACL injuries, low-quality data have been produced that reveals no difference in patient-reported knee function results between surgical ACL restoration and conservative therapy. However, these results must be evaluated in the perspective of the fact that many individuals with an ACL rupture remained symptomatic after rehabilitation and eventually underwent ACL reconstruction surgery. This article has reviewed the risk factors and the mechanisms that commonly lead to ACL injuries. This article has also discussed the clinical significance of conservative and surgical management and has highlighted the implications of both approaches.

MRI Findings of Early Osteoarthritis in Patients Who Sustained Septic Arthritis of the Knee After ACL Reconstruction

Background:

Although a rare complication, septic arthritis (SA) after anterior cruciate ligament (ACL) reconstruction has potentially devastating consequences for the knee joint.

Purpose:

To prospectively analyze, at a mean 4-year follow-up, subjective, clinical, radiographic, and magnetic resonance imaging (MRI) findings between patients with SA and those with no septic complication after ACL reconstruction.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Of 2006 ACL reconstructions performed between 2004 and 2014, a total of 20 patients experienced SA. All patients were treated with arthroscopic irrigation and graft-retaining debridement immediately after diagnosis and at least 6 weeks of antibiotic treatment. After the exclusion process, 18 patients were included in the SA group and 20 in the control group. At final follow-up at a mean 48 months, a physical examination, KT-1000 arthrometer laxity test, Lysholm knee score, Tegner activity score, and International Knee Documentation Committee radiographic score were completed and then compared with preoperative data. The Boston-Leeds Osteoarthritis Knee Score was used for MRI evaluation at final follow-up to note chondral changes.

Results:

No significant differences between the SA and control groups were observed in pre- and perioperative variables that could indicate a higher incidence of early osteoarthritis (OA). Although range of motion and knee stability were not significantly different between the groups at final follow-up, the Lysholm score (mean ± SD, 79.8 ± 13.1 vs 90.9 ± 8.6; P < .01) and Tegner score (6.0 ± 1.1 vs 7.0 ± 1.4; P = .03) were significantly lower in the SA group as compared with the control group. MRI evaluation at final follow-up demonstrated a significantly higher degree of early knee OA in the SA group versus the control group. However, no differences in the degree of OA were seen on plain radiographs at final follow-up between the groups.

Conclusion:

MRI evaluation provided signs of worsened chondral state in the SA group, which could be associated with reduced functional outcome and return to sports. In contrast to radiograph analyses, MRI was excellent at distinguishing damage to the cartilage and can be useful in early follow-up evaluation of patients with SA after ACL reconstruction.

Comparison of the Sterilization Efficiency of 3 Disinfectants for Dropped Anterior Cruciate Ligament Grafts: A Systematic Review and Meta-analysis

Background:

The inadvertent contamination of anterior cruciate ligament (ACL) grafts can occur if they are accidentally dropped on the floor during ACL reconstruction. There has been no meta-analysis conducted to compare the sterilization efficiency of the different disinfectants used on dropped ACL grafts.

Purpose:

To compare the sterilization efficiency of 3 disinfectants to decontaminate ACL grafts as necessary.

Study Design:

Systematic review.

Methods:

A systematic literature review was performed using the MEDLINE, Embase, and Cochrane Library databases. All studies reporting the management of dropped or contaminated grafts were considered for this meta-analysis.

Results:

A total of 7 studies meeting inclusion criteria were identified from a literature search. The pooled results of this meta-analysis indicated that the rate of positive cultures of ACL grafts dropped on the operating room floor was 44.9% and that the commonly contaminated microbes were staphylococci and bacilli. The meta-analysis results indicated that the sterilization efficiency of a 4% chlorhexidine solution was superior to an antibiotic solution (odds ratio [OR], 0.17 [95% CI, 0.05-0.57]; P = .004) and a 10% povidone-iodine solution (OR, 0.04 [95% CI, 0.01-0.20]; P < .0001). Further, the antibiotic solution was superior to the 10% povidone-iodine solution (OR, 0.20 [95% CI, 0.07-0.55]; P = .002).

Conclusion:

The results of our meta-analysis demonstrated that staphylococci and bacilli were the most common contaminants on dropped ACL grafts and that decontamination using a 4% chlorhexidine solution more reliably disinfected ACL grafts. This information can help to guide surgeons as regards appropriate remedial measures.

White Blood Cell Count Is the Most Reliable Test for the Diagnosis of Septic Arthritis After Anterior Cruciate Ligament Reconstruction: An Observational Study of 38 Patients

PURPOSE

(1) To evaluate the diagnostic testing performance of the synovial white blood cell (WBC) count, polymorphonuclear cell percentage, and synovial glucose, synovial protein, synovial lactate dehydrogenase, and synovial C-reactive protein levels as diagnostic markers for the diagnosis of septic arthritis after anterior cruciate ligament (ACL) reconstruction; (2) to define the ideal thresholds of the aforementioned tests, leading to the optimal sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy; and (3) to define the sensitivity of synovial fluid culture and synovial tissue sample culture, as well as determine whether previous antibiotic treatment may affect the accuracy of these tests.

METHODS

We performed a retrospective analysis of all patients readmitted from January 2009 to September 2019 with signs suggestive of septic arthritis and undergoing a knee aspiration for synovial fluid analysis and culture. The receiver operating characteristic curve and the associated area under the curve were constructed for the aforementioned synovial markers. Sensitivity, specificity, PPV, NPV, and accuracy were calculated for the obtained optimal values. Sensitivity was also calculated for synovial fluid culture and synovial tissue sample culture, and the influence of previous antibiotic treatments on culture sensitivity was evaluated.

RESULTS

Among 3,408 cases of ACL reconstruction, after the exclusion of 13 patients not meeting the inclusion criteria, 24 infected and 14 uninfected patients were reviewed and included in the analysis. The diagnosis was confirmed by the presence of 2 positive culture findings with the same isolated microorganism or at least 3 of the 4 following criteria: elevated serum C-reactive protein level and erythrocyte sedimentation rate, positive results of histologic analysis of synovial tissue, macroscopic evidence of purulence, and 1 positive culture finding. The receiver operating characteristic curve analysis showed that the most reliable marker for the diagnosis of septic arthritis after ACL reconstruction was the synovial WBC count (area under the curve, 0.89). A cutoff value of 28,100 cells/mL presented the highest accuracy (0.85), highest PPV (0.94), and highest NPV (0.76); moreover, with the threshold set at 40,000 cells/mL, postoperative infection could be diagnosed with 100% specificity. The sensitivity of synovial fluid culture was significantly lower than the sensitivity of synovial tissue sample culture (0.63 vs 0.96, P = .0045); moreover, the sensitivity further decreased if patients took antibiotics before aspiration (0.44 vs 0.73), although this decrease was not statistically significant.

CONCLUSIONS

The synovial WBC count is the most reliable test for the diagnosis of septic arthritis after ACL reconstruction. Although the sensitivity of synovial fluid culture is affected by previous antibiotic treatment, the synovial WBC count is not influenced and proves to be useful in the diagnosis of this uncommon complication.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Editorial Commentary: Synovial Fluid White Blood Cell Is the Gold Standard to Detect Infection After Anterior Cruciate Ligament Reconstruction: Don't Hesitate to Aspirate

Infection after anterior cruciate ligament reconstruction can have devastating consequences, including potential graft loss, arthrofibrosis, chondral destruction or chondrolysis, and secondary osteoarthritis. Early detection and aggressive management are imperative to improve the chances of infection eradication, graft retention, and to decrease the risk of chondral loss. One must have a high index of suspicion and not shy away from working up a possible infection. Synovial fluid aspiration and cell count, specifically white blood cell count, is the gold standard to diagnose postoperative infection.

Management Guidelines for Infection After ACL Reconstruction: Expert Opinion Statement Based on the Modified Delphi Survey of Indian Arthroscopy Surgeons

AIM

Infection after anterior cruciate ligament (ACL) reconstruction, though rare, is a potentially devastating complication and the evidence-based recommendation on the various topics in its management is limited. The purpose of this study was to develop recommendations for the prevention and management of infections in ACL reconstruction surgery by performing a structured expert consensus survey using Delphi methodology.

MATERIALS AND METHODS

22 topics of relevance in the prevention and management of infection following ACL reconstruction were chosen from an extensive literature review. 30 panelists were requested to respond to a three-round survey, with feedback, to develop a consensus statement on the topics.

RESULTS

Consensus statements could be prepared in eleven out of twenty-two topics including: the graft is retained at the first arthroscopic debridement, the graft is removed when repeated debridement are needed, and revision ACL reconstruction is needed only if the patient develops instability. Concurrence could be obtained in the topics including: longer duration of antibiotics is needed in immunocompromised patients, soaking graft in antibiotic solution reduces infection risk, and knee swelling without warmth does not suggest infection.

CONCLUSIONS

A proper skin preparation, a longer course of antibiotics in immunocompromised patients, and soaking the graft in antibiotics reduces the risk of infection. In case of infection, a healthy-looking graft must be retained at the first debridement and if the graft must be removed, revision ACL reconstruction is advised only if the patient develops instability.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00363-z.

Lower incidence of post-operative septic arthritis following revision anterior cruciate ligament reconstruction with quadriceps tendon compared to hamstring tendons

PURPOSE

To determine and compare the incidence of post-operative septic arthritis following revision anterior cruciate ligament reconstruction (R-ACLR) with autologous quadriceps tendon (with patellar bone block) compared to autologous hamstring tendons (semitendinosus and gracilis).

METHODS

A total of 1638 isolated R-ACLR with either autologous hamstring tendons (n = 1004, 61.3%) or quadriceps tendon (n = 634; 38.7%) were performed between 2004 and 2017 and were retrospectively analysed with regard to the occurrence of post-operative septic arthritis. The technique of R-ACLR did not significantly change during the years of the study. All patients received pre-op i.v.antibiotics, but no presoaking of the grafts in vancomycin was performed in the years of the study. The individual decision of graft choice was based on graft availability, tunnel position and the presence of tunnel widening. Generally, hamstring tendons were preferred. There were no clinically relevant differences between the groups regarding gender or age. Routine follow-up examination was performed 6 weeks after the index operation (follow-up rate 96.5%), and patients unsuspicious for septic arthritis at that time were classified as non-infected.

RESULTS

Fourteen patients with septic arthritis were identified, resulting in an overall incidence of 0.85%. There was one patient with septic arthritis in the quadriceps tendon group (incidence: 0.16%) and 13 patients in the hamstring tendons group (incidence: 1.29%), respectively. The difference was significant (p = 0.013).

CONCLUSION

In this series, the incidence of post-operative septic arthritis after R-ACLR was lower when quadriceps tendon graft was used compared to hamstring tendon grafts.

LEVEL OF EVIDENCE

III.

Soaking of the graft in vancomycin dramatically reduces the incidence of postoperative septic arthritis after anterior cruciate ligament reconstruction

PURPOSE

To determine and compare the incidence of postoperative septic arthritis following anterior cruciate ligament reconstruction (ACLR) with and without soaking of the graft in vancomycin solution prior to implantation in a large single-centre case series.

METHODS

From 2004 to 2019, a total of 10,516 primary ACLR were performed and reviewed with regard to the occurrence of postoperative septic arthritis. From February 2017 onwards, all grafts were wrapped in a vancomycin-soaked (5 mg/ml) gauze swab between harvest and implantation (2294 patients, treatment group (2), prospectively followed). These were compared to 8222 patients before that date (control group (1), retrospectively evaluated). The technique of ACLR did not significantly change during the years of the study. There was no difference between the groups with regard to graft choice: Hamstring tendons were used in 99% and quadriceps tendons were used in 1% in both groups, respectively (n.s.). Routine follow-up examination was performed at 6 weeks (follow-up rate 97.1%) postoperatively. Patients with no treatment for septic arthritis at that time were classified as non-infected.

RESULTS

There were 35 cases of postoperative septic arthritis in group 1 (incidence: 0.4%), and none in group 2 (incidence 0.0%), respectively. The difference was significant (p < 0.001).

CONCLUSIONS

Soaking of the graft in vancomycin solution prior to implantation dramatically reduces the incidence of postoperative septic arthritis in primary ACLR and should, therefore, be used in prevention of this major complication.

LEVEL OF EVIDENCE

III.

Graft-Preserving Arthroscopic Debridement With Hardware Removal Is Effective for Septic Arthritis After Anterior Cruciate Ligament Reconstruction: A Clinical, Arthrometric, and Magnetic Resonance Imaging Evaluation

BACKGROUND

Arthroscopic debridement with graft preservation has been advocated as the treatment of choice for septic arthritis after anterior cruciate ligament (ACL) reconstruction, but no previous studies have investigated if hardware removal, while retaining the graft in situ, improves the success rate. Moreover, it is unclear whether the premature removal of fixation devices may affect graft integration and knee stability.

PURPOSE/HYPOTHESIS

The purpose was to assess the clinical and functional outcomes of patients with septic arthritis after ACL reconstruction who underwent arthroscopic debridement, while retaining the graft in situ but removing fixation devices, and to determine if premature hardware removal affects graft integrity and function. The hypothesis was that arthroscopic debridement with hardware removal would be effective in eradicating infections while not compromising graft integration and function.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From a cohort of 2384 cases of arthroscopic ACL reconstruction, 24 patients with postoperative septic arthritis were included for the analysis; 18 patients were available for a clinical evaluation using the International Knee Documentation Committee (IKDC) form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, and Tegner score at a minimum 12-month follow-up. Knee laxity was assessed clinically with standardized manual laxity tests and instrumentally using an arthrometer and a triaxial accelerometer. Additionally, 3-T magnetic resonance imaging (MRI) at final follow-up was performed, focusing on the graft signal, the cartilage status, and the occurrence of arthrofibrosis.

RESULTS

Eradication of the infection was achieved in all cases, and only 1 graft removal was performed because of insufficient tension. Among the remaining 23 patients, a single arthroscopic debridement procedure with hardware removal while preserving the graft was effective in 21 cases (91%) at a mean of 30 ± 37 days from ACL reconstruction to debridement. At last follow-up, 2 patients required a further ACL revision procedure. The mean IKDC, WOMAC, Lysholm, and Tegner scores of the patients available for the clinical evaluation were 75 ± 19, 90 ± 8, 79 ± 21, and 6 ± 2, respectively. No abnormal laxity was reported on manual testing, and arthrometric and accelerometer tests also demonstrated good knee stability (mean KT-1000 arthrometer side-to-side difference was 1.6 ± 1.2 mm at manual maximum force). On MRI, a good graft signal was found in 50% of cases, while concomitant signs of arthrofibrosis were detected in 81% of patients. Severe cartilage defects (International Cartilage Repair Society grade ≥3) were reported in 63% of cases.

CONCLUSION

Arthroscopic debridement with hardware removal was effective in the eradication of infections after ACL reconstruction with extra-articular fixation while preserving graft integrity without compromising knee stability. Patients and surgeons should be aware of complications that might affect the outcome, particularly arthrofibrosis and chondrolysis.

Nocardia nova Infection of Tibia Tenodesis Implant After Anterior Cruciate Ligament Reconstruction in an Immunocompetent Patient

Infection after anterior cruciate ligament reconstruction and Nocardia infection in immunocompetent hosts are rare events in isolation. This case report highlights the rare combination of these events in a 46-year-old healthy man who acquired a Nocardia nova infection of the tibia tunnel site after an anterior cruciate ligament reconstruction with peroneus allograft. He was successfully treated with tibial tenodesis screw removal, two surgical debridements, and 4 weeks of trimethoprim-sulfamethoxazole and meropenem, followed by 6 months of clarithromycin and original graft retention. This report will review the current antibiotic recommendations and surgical management of this challenging situation. Our case is unique in that the infection was isolated to the distal aspect of the tibial tunnel and did not spread into the entire knee joint, highlighting the importance of early debridement and irrigation in the operative suite when graft site infection is suspected.

Soaking of autografts in vancomycin is highly effective in preventing postoperative septic arthritis after revision anterior cruciate ligament reconstruction

PURPOSE

To determine and compare the incidence of postoperative septic arthritis following revision anterior cruciate ligament reconstruction (R-ACLR) with and without soaking of the graft in vancomycin solution prior to implantation in a large single-centre series.

METHODS

A total of 2155 isolated R-ACLR with autologous tendons were performed from 2004 to 2019 and were reviewed with regard to the occurrence of postoperative septic arthritis. From February 2017 onwards, all grafts were wrapped in a vancomycin-soaked (5 mg/ml) gauze swab between harvest and implantation (517 patients, treatment group (2), prospectively followed). These were compared to 1638 patients before that date (control group (1), retrospectively evaluated). The technique of R-ACLR did not significantly change during the years of the study. Hamstring tendons were used in 1310 patients (60.8%) and quadriceps tendons with patellar bone block were used in 845 patients (39.2%), respectively, with no difference between the groups (n.s.). Routine follow-up examination was performed 6 weeks postoperatively (follow-up rate 96.5%), and patients with no treatment for septic arthritis until that time were classified as non-infected.

RESULTS

There were 14 cases of postoperative septic arthritis in group 1 (incidence 0.9%), and none in group 2 (incidence 0.0%), respectively. The difference was significant (p = 0.029).

CONCLUSION

Soaking of the graft in vancomycin solution prior to implantation dramatically reduces the incidence of postoperative septic arthritis in R-ACLR.

LEVEL OF EVIDENCE

III.