Recommendations for the management of septic arthritis after ACL reconstruction

Presoaking hamstring autograft with vancomycin does not jeopardize its biomechanical properties, including graft elongation, after cyclic loading

PURPOSE

Presoaking the graft with vancomycin before implantation has been shown to reduce the risk of postoperative infection after anterior cruciate ligament reconstruction (ACLR). However, the effects of presoaking on the graft biomechanical properties remain unclear. This study aimed to determine whether presoaking the graft with vancomycin affects the graft biomechanical properties and length after cyclic loading.

METHODS

Ten paired (20 specimens) gracilis and semitendinous tendons were harvested from fresh-frozen human cadaveric specimens. Two tendons were folded in half to make four strands, and the grafts were randomized into the vancomycin and control groups. The graft was exposed to the antibiotic solution for 15 min (5 mg/mL) and prepared by mixing 1 g of vancomycin with 200 mL of normal saline (NaCl 0.9%). The control group was soaked in normal saline for 15 min. The prepared grafts were attached to the actuator of a dynamic tensile-testing machine. All grafts were tested with 3000 cycles of cyclic loading followed by a pull-to-failure. The cyclic loading protocol consisted of position and load control blocks to simulate the graft in vivo in the postoperative phase after ACLR.

RESULTS

Presoaking in vancomycin did not jeopardize the biomechanical properties of the graft. In addition, presoaking with vancomycin did not elongate the grafts. No significant differences were found in the mean Young's modulus and the mean total elongation of the graft of the specimen between the vancomycin group and the control group.

CONCLUSION

Presoaking the graft with vancomycin jeopardized neither its biomechanical properties nor elongation even after cyclic loading in this in vitro study. It is suggested that vancomycin presoaking could be considered a safe and effective preventive measure for postoperative infections after ACLR.

LEVEL OF EVIDENCE

Not applicable.

Infection after Anterior Cruciate Ligament Reconstruction: A Narrative Review of the Literature

Infection is an uncommon side effect of arthroscopic surgery, and this percentage is higher in anterior cruciate ligament reconstruction (ACLR) surgery, where graft and fixation devices are used. Infections can not only lead to high re-admission rates and poor functional recovery of the knee but can also have a significant negative impact on the patient's psychological and economic health, especially in athletes, as it can affect their sports career. It is important to be aware of the many risk factors, especially the manifestation of symptoms. These may sometimes be non-specific to the infectious pathology and common to other situations, such as the presence of a significant intra-articular hematoma. Septic arthritis after ACLR can occur at any time after surgery but typically presents acutely, while late manifestation is relatively rare. Diagnosis of infection is based on patient history, physical examination, laboratory parameters, and analysis of synovial fluid after joint aspiration, which is the gold standard for diagnosing post-operative infection. Once symptoms appear and the diagnosis seems certain, it is necessary to intervene quickly with arthroscopic debridement and long-term antibiotic treatment to try to save the graft and resolve the infectious situation to avoid graft failure and arthrofibrotic sequelae. The aim of this paper is to provide an overview of the epidemiology, pathogenesis, risk factors, clinical presentation, diagnostic evaluation, and current treatment guidelines of septic arthritis after ACLR surgery by analyzing recent literature, in particular meta-analyses and systematic reviews.

Atypical mycobacterium infection following anterior cruciate ligament reconstruction

A man in his 20s presented with instability of the right knee following an incident of fall from a height. He was clinicoradiologically diagnosed to have an anterior cruciate ligament (ACL) tear for which he underwent ACL reconstruction. Postoperatively, he was started on an accelerated ACL rehabilitation protocol. Six weeks postoperatively, he developed features of subclinical septic arthritis for which he underwent arthroscopic debridement. Intraoperative samples cultured Mycobacterium abscessus complex on MGIT 960 system. The patient subsequently had to undergo another debridement after 1 month as there were clinical signs of persisting infection. The graft was intact even on the second debridement and after removing the implants. This case reports a rare complication of ACL reconstruction with infection by atypical mycobacterium and the clinical outcome. It also emphasises that prompt surgical intervention can save the graft.

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.

A Systematic Review and Meta-analysis of Risk Factors for an Infection After Anterior Cruciate Ligament Reconstruction

Background

Identifying risk factors for an infection after anterior cruciate ligament reconstruction (ACLR) and following targeted preventive strategies can effectively reduce this potentially serious complication.

Purpose

To perform a systematic review and meta-analysis to identify the risk factors for an infection after ACLR.

Study Design

Systematic review; Level of evidence, 4.

Methods

The PubMed, Embase, and Web of Science databases were searched from inception to September 1, 2022, for prospective and retrospective studies investigating risk factors for any type of infection after ACLR. Odds ratios (ORs) or mean differences were calculated for potential risk factors if ≥2 studies assessed the same risk factor. A qualitative analysis of variables was performed if a meta-analysis could not be conducted.

Results

A total of 17 studies with 141,991 patients were included in this review. The overall pooled infection rate was 0.86% (range, 0.24%-5.50%). There were 20 risk factors identified for analysis. Of these, 7 variables independently increased the odds of an infection after ACLR: (1) male sex (OR, 1.90 [95% CI, 1.33-2.73]), (2) diabetes (OR, 2.69 [95% CI, 1.66-4.35]), (3) hamstring tendon autograft (OR, 2.51 [95% CI, 2.03-3.10]), (4) revision ACLR (OR, 2.31 [95% CI, 1.22-4.37]), (5) professional athlete status (OR, 6.21 [95% CI, 1.03-37.38]), (6) lateral tenodesis (OR, 3.45 [95% CI, 1.63-7.28]), and (7) corticosteroid use (OR, 7.83 [95% CI, 3.68-16.63]). No significant associations were found between postoperative infections and age, body mass index, smoking, meniscal repair, or outpatient surgery.

Conclusion

This review revealed that an increased risk of infections after ACLR was associated with male sex, diabetes, hamstring tendon autograft, revision surgery, professional athlete status, lateral tenodesis, and steroid use. Knowledge of the risk factors associated with an infection after ACLR may facilitate the identification of high-risk cases and the implementation of preventive measures to mitigate the serious consequences of this complication.

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.

The early infection characterization of septic arthritis by Staphylococcus aureus after anterior cruciate ligament reconstruction in a novel rat model

BACKGROUND

The present study aimed to explore the time of maximum bacterial load and main colonization knee site in bacterial infection process based on a novel rat model of septic arthritis (SA) after anterior cruciate ligament reconstruction (ACLR).

METHODS

Ninety-five Wistar rats with unilateral ACLR, random enrolled into control surgery (CS) group; joint inject (JI) group; presoaking (PS) group, were injected with 30 μl sterile saline or 30 μl × 10⁷ colony forming units/ml Staphylococcus aureus via the knee joint or graft with presoaked Staphylococcus aureus during ACLR, respectively. At 1, 4, 7, 11, and 14 days postoperatively, samples were harvested to evaluate progress of knee joint infection by postoperative body weight, body temperature, knee temperature, knee width, scales of tissue damage, serum inflammatory markers, microbiological counting, microcomputed tomography (Micro-CT), digital radiography, magnetic resonance imaging (MRI) examination, and scanning electron microscopy (SEM).

RESULTS

No systemic infection was observed in all rats. Comparing with serum inflammatory markers, tissue scores of inflammatory reactions, bacterial counts in the CS group, these data were significantly elevated in the JI group and PS group. The bone mass around the bone tunnel was lower and the soft tissue of knee showed more obvious swelling on MRI in the infection groups than that in the CS group at 7 and 14 days postoperatively. Staphylococcus aureus clusters on the surface of screw and graft were observed in the infection group. The whole colony forming units of Staphylococcus aureus maintained a continuous upward trend peaking 7 and 11 days followed by a balanced curve in the infection groups. Bone and soft tissue were found to have more bacterial counts than graft and screws.

CONCLUSION

This animal model effectively mimics the acute knee infection after ACLR. We found that the bacterial colonization exhibited the peak of acute infection between 7 and 11 days postoperatively, with the major bacteria loads found in the bone, soft tissue.

In Vitro Study of Gentamicin Elution from Tendon Grafts

Background

Though vancomycin-soaked graft reduces the infection rate after ACL reconstruction, concerns exist regarding this usage. Gentamicin has been used for graft soakage with satisfactory clinical results but gentamicin's elution characteristics are unknown.

Methods

Thirty Bovine tendon grafts were harvested from ten limbs under sterile conditions. Three tendons from each of the limbs were allotted into three groups and soaked in either saline, gentamicin or vancomycin. Pre-soakage and post-soakage swabs were cultured. Soaked grafts were immersed in a 10 ml saline solution for 5 min (initial washout) and then in another 10 ml saline solution (sustained release) for 10 min. No 1 Whatman filter paper was immersed in the solutions and placed on culture plates streaked with coagulase-negative Staphylococcus aureus (CONS) and methicillin-resistant Staphylococcus aureus (MRSA), and inhibition was noted. The difference between the two proportions was assessed by two proportion t-test for p < 0.05.

Results

No organism was cultured in the pre-soakage or post-soakage swab in any specimen. Specimens from one limb were excluded since saline-soakage showed inhibition. Elution from gentamicin-soaked graft inhibited CONS in eight out of nine samples in initial washout and all samples in sustained release solution but inhibited MRSA only in one sample in sustained release solution and the initial washout solution. Vancomycin elution inhibited both organisms in all samples.

Conclusions

Gentamicin elution from tendon graft achieves minimal inhibitory concentration against susceptible organisms. Though its clinical utility is restricted by limited antimicrobial spectrum, and it could be used where the risk of contamination by MRSA is low.

Recommendations on diagnosis and antimicrobial treatment of infections after anterior cruciate ligament reconstruction (ACL-R) endorsed by ESSKA and EBJIS

Infection after anterior-cruciate ligament reconstruction (ACL-R) is a rare but devastating complication affecting predominantly young and sportive individuals. A timely and correct diagnosis as well as an optimized management are paramount to circumvent serious sequelae and compromise in life quality. These recommendations are primarily intended for use by infectious disease specialists and microbiologists, but also orthopedic surgeons and other healthcare professionals who care for patients with infections after ACL-R. They are based on evidence mainly originating from observational studies and opinions of experts in the field and cover the management of infections after ACL-R with a special focus on etiology, diagnosis, antimicrobial treatment and prevention. Comprehensive recommendations on prevention, surgical treatment and rehabilitation are presented separately in a document primarily addressing orthopedics professionals.

SPILF update on bacterial arthritis in adults and children

In 2020 the French Society of Rhumatology (SFR) published an update of the 1990 recommendations for management of bacterial arthritis in adults. While we (French ID Society, SPILF) totally endorse this update, we wished to provide further information about specific antibiotic treatments. The present update focuses on antibiotics with good distribution in bone and joint. It is important to monitor their dosage, which should be maximized according to PK/PD parameters. Dosages proposed in this update are high, with the optimized mode of administration for intravenous betalactams (continuous or intermittent infusion). We give tools for the best dosage adaptation to conditions such as obesity or renal insufficiency. In case of enterobacter infection, with an antibiogram result "susceptible for high dosage", we recommend the requesting of specialized advice from an ID physician. More often than not, it is possible to prescribe antibiotics via the oral route as soon as blood cultures are sterile and clinical have symptoms shown improvement. Duration of antibiotic treatment is 6 weeks for Staphylococcus aureus, and 4 weeks for the other bacteria (except for Neisseria: 7 days).

Risk factors for postoperative surgical site infections after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

OBJECTIVES

The primary aim was to evaluate risk factors for surgical site infections after anterior cruciate ligament reconstruction (ACLR). The secondary aim was to investigate the surgical site infection incidence rate and the mean time to postoperative surgical site infection symptoms.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase and Web of Science were searched from database inception to September 2021 and updated in April 2022.

ELIGIBILITY CRITERIA

Quantitative, original studies reporting potential risk factors for surgical site infections after ACLR were included.

RESULTS

Twenty-three studies with 3871 infection events from 469 441 ACLRs met the inclusion criteria. Male sex (OR 1.78, p< 0.00001), obesity (OR 1.82, p=0.0005), tobacco use (OR 1.37, p=0.01), diabetes mellitus (OR 3.40, p=0.002), steroid use history (OR 4.80, p<0.00001), previous knee surgery history (OR 3.63, p=0.02), professional athlete (OR 4.56, p=0.02), revision surgery (OR 2.05, p=0.04), hamstring autografts (OR 2.83, p<0.00001), concomitant lateral extra-articular tenodesis (OR 3.92, p=0.0001) and a long operating time (weighted mean difference 8.12, p=0.005) were identified as factors that increased the risk of surgical site infections (superficial and deep) after ACLR. Age, outpatient or inpatient surgery, bone-patellar tendon-bone autografts or allografts and a concomitant meniscus suture did not increase the risk of surgical site infections. The incidence of surgical site infections after ACLR was approximately 1% (95% CI 0.7% to 1.2%). The mean time from surgery to the onset of surgical site infection symptoms was approximately 17.1 days (95% CI 13.2 to 21.0 days).

CONCLUSION

Male sex, obesity, tobacco use, diabetes mellitus, steroid use history, previous knee surgery history, professional athletes, revision surgery, hamstring autografts, concomitant lateral extra-articular tenodesis and a long operation time may increase the risk of surgical site infections after ACLR. Although the risk of surgical site infections after ACLR is low, raising awareness and implementing effective preventions for risk factors are priorities for clinicians to reduce the incidence of surgical site infections due to its seriousness.

A Review of Evidence for Infection Reduction With Vancomycin-treated Anterior Cruciate Ligament Grafts

Septic arthritis after anterior cruciate ligament (ACL) reconstruction is a rare but devastating complication. Several risk factors and known sources of infection have been identified in the literature. There is growing interest and supportive evidence for a targeted invention aimed at graft decontamination, which has led some surgeons to adopt the use of antibiotic solution soaks and/or wraps applied to ACL grafts before graft implantation in an attempt to reduce the risk of postoperative infection. Despite this, adoption of this technique remains relatively low among surgeons because of a variety of factors: (1) lack of awareness, (2) confusion over optimal protocols, (3) concern for graft viability and clinical outcomes, and (4) efforts to minimize the cost of surgery. However, recently published literature demonstrates notable risk reduction for infection, acceptable safety, no detrimental effect on clinical outcomes, and overall cost-effectiveness with the use of vancomycin graft soaks and wraps. Currently, there is a lack of consensus for clinical protocols, and the protocol that is most efficacious remains unclear. The purpose of this review article was to present the current evidence for ACL graft treatment with vancomycin for the prevention of postoperative infection.

Effect of Joint Infection After Arthroscopic Single-Bundle ACL Reconstruction With Autologous Hamstring Tendon: A Retrospective Matched MRI Study

Background:

Joint infection after anterior cruciate ligament (ACL) reconstruction is a rare but serious complication.

Purpose:

To assess the effect of joint infection on the graft, cartilage, and bone tunnel using magnetic resonance imaging (MRI) after arthroscopic single-bundle ACL reconstruction with autologous hamstring tendons.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This retrospective matched cohort study included 26 patients who underwent arthroscopic single-bundle ACL reconstruction with hamstring tendon graft at the authors’ institute between January 2002 and December 2017 and developed postoperative joint infection. These patients were matched 1:3 to patients who did not sustain joint infection after ACL reconstruction (control group). MRI scans were collected at the time of follow-up. The following parameters were evaluated: graft signal-to-noise quotient (SNQ); graft signal intensity at the bone-graft interface and within the knee joint; bone tunnel enlargement at the tunnel aperture, midsection, and exit of the tibial and femoral tunnels; and cartilage integrity.

Results:

The average follow-up time was 47.8 months in the infection group and 48.5 months in the control group. Compared with the control group, the infection group had a significantly higher SNQ (20.01 ± 12.08 vs 7.61 ± 6.70; P = .014) as well as a higher signal intensity at the bone-graft interface (P = .037) and higher Howell grade (P = .031). The mean enlargement at the femoral tunnel aperture was 31.20% ± 26.76% in the infection group and 19.22% ± 20.10% in the control group (P = .037). The articular cartilage of the patellofemoral and lateral femorotibial joints showed more degenerative change in the infection group.

Conclusion:

Study findings indicated that graft ligamentization and incorporation graft maturity were inferior in patients who experienced a joint infection after ACL reconstruction compared with patients who did not.

Factors Associated With an Intra-articular Infection After Anterior Cruciate Ligament Reconstruction: A Large Single-Institution Cohort Study

BACKGROUND

An intra-articular infection after anterior cruciate ligament (ACL) reconstruction (ACLR) is a rare complication but one with potentially devastating consequences. The rare nature of this complication raises difficulties in detecting risk factors associated with it and with worse outcomes after one has occurred.

PURPOSE

To (1) evaluate the association between an infection after ACLR and potential risk factors in a large single-center cohort of patients who had undergone ACLR and (2) assess the factors associated with ACL graft retention versus removal.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

All ACLR procedures performed at our institution between January 2010 and December 2018 were reviewed; a total of 11,451 procedures were identified. A retrospective medical record review was performed to determine the incidence of infections, patient and procedure characteristics associated with an infection, infection characteristics, incidence of ACL graft retention, and factors associated with the retention versus removal of an ACL graft. Multivariable logistic regression analysis was used to identify potential risk factors for an infection after ACLR.

RESULTS

Of the 11,451 ACLR procedures, 48 infections were identified (0.42%). Multivariable logistic regression analysis revealed revision ACLR (odds ratio [OR], 3.13 [95% CI, 1.55-6.32]; P = .001) and younger age (OR, 1.06 [95% CI, 1.02-1.10]; P = .001) as risk factors for an infection. Compared with bone-patellar tendon-bone autografts, both hamstring tendon autografts (OR, 4.39 [95% CI, 2.15-8.96]; P < .001) and allografts (OR, 5.27 [95% CI, 1.81-15.35]; P = .002) were independently associated with an increased risk of infections. Overall, 15 ACL grafts were removed (31.3%). No statistically significant differences besides the number of irrigation and debridement procedures were found for retained versus removed grafts, although some trends were identified (P = .054).

CONCLUSION

In a large single-center cohort of patients who had undergone ACLR and those with an infection after ACLR, patients with revision cases and younger patients were found to have a higher incidence of infection. The use of bone-patellar tendon-bone autografts was found to be associated with the lowest risk of infection after ACLR compared with both hamstring tendon autografts and allografts. Larger cohorts with a larger number of infection cases are needed to determine the factors associated with graft retention versus removal.

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.

Vancomycin Soaking Is Highly Cost-Effective in Primary ACLR Infection Prevention: A Cost-Effectiveness Study

BACKGROUND

Although presoaking grafts in vancomycin has been demonstrated to be effective in observational studies for anterior cruciate ligament reconstruction (ACLR) infection prevention, the economic benefit of the technique is uncertain.

PURPOSE

To 1) determine the cost-effectiveness of vancomycin presoaking during primary ACLR to prevent postoperative joint infections and 2) to establish the break-even cost-effectiveness threshold of the technique and determine its cost-effectiveness across various international health care settings.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

A Markov model was used to determine cost-effectiveness and the incremental cost-effectiveness ratio of additional vancomycin presoaking compared with intravenous antibiotic prophylaxis alone. A repeated search of the PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials databases, using the same criteria as a recent meta-analysis, was completed. A repeated meta-analysis of 9 cohort studies (level 3 evidence) was completed to determine the odds ratio of infection with vancomycin presoaking compared with intravenous antibiotics alone. Estimated costs of the vancomycin technique, treatment of infection, and further surgery were sourced from local hospitals and literature. Transitional probabilities for further surgery, including revision reconstruction and primary arthroplasty, were obtained from the literature. Probabilistic sensitivity analyses and a 1-way sensitivity analysis were performed to evaluate the ACLR infection rate break-even threshold for which the vancomycin technique would be no longer cost-effective.

RESULTS

The vancomycin soaking technique provides expected cost savings of $660 (USA), A$581 (Australia), and €226 (Spain) per patient. There was an improvement in the quality-adjusted life-years of 0.007 compared with intravenous antibiotic prophylaxis alone (4.297 vs 4.290). If the infection rate is below 0.014% with intravenous antibiotics alone, the vancomycin wrap would no longer be cost-effective.

CONCLUSION

The vancomycin presoaking technique is a highly cost-effective method to prevent postoperative septic arthritis after primary ACLR.

Presoaking ACL Grafts in Vancomycin Decreases the Frequency of Postoperative Septic Arthritis: A Cohort Study of 29,659 Patients, Systematic Review, and Meta-analysis From the SANTI Study Group

Background:

Presoaking anterior cruciate ligament (ACL) grafts in vancomycin has been reported to reduce the occurrence of septic arthritis (SA). However, strong recommendations for its universal use have been precluded by concerns regarding the fragility of previous meta-analyses.

Purpose:

The primary objective was to investigate whether presoaking ACL grafts in vancomycin was associated with a reduction in the rate of SA in a large series of patients. The secondary objective was to perform an updated systematic review and meta-analysis to determine the efficacy of vancomycin in reducing the rate of SA.

Study Design:

Cohort study and systematic review; Level of evidence, 3.

Methods:

A retrospective analysis of patients who underwent primary ACL reconstruction (ACLR) at our institution was undertaken. Rates of postoperative SA were determined and analyzed according to whether patients had received grafts presoaked in vancomycin. A systematic review of the literature and meta-analysis was performed. Odds ratios (ORs) for the risk of SA were calculated according to the inverse variance approach. Results were presented using forest plots, funnel plots, and the fragility index.

Results:

A total of 5300 patients underwent primary ACLR during the study period. The rate of SA was 0.34% (11/3228) in the control group and 0.05% (1/2072) in the presoaked group. There was a 5-fold greater risk of SA in patients who did not receive grafts presoaked in vancomycin (OR, 5.13 [95% CI, 1.16-48.30]; P = .04). Overall, 11 studies were included in the systematic review (29,659 ACLR procedures). The meta-analysis demonstrated a significantly greater risk of SA in those patients who did not receive grafts presoaked in vancomycin (OR, 14.39 [95% CI, 5.90-35.10]; fragility index = 23). This finding held true for the subpopulation receiving hamstring tendon grafts (fragility index = 16), but only a trend was demonstrated for bone–patellar tendon–bone grafts.

Conclusion:

The meta-analysis demonstrated that presoaking ACL grafts in vancomycin was associated with significant reductions in the rates of SA when all graft types were analyzed together. This finding held true specifically for hamstring tendon autografts. The fragility index of these findings allows for a strong recommendation for the universal use of vancomycin presoaking. However, it should be noted that only a trend toward reduced SA rates was demonstrated with presoaking bone–patellar tendon–bone autografts in vancomycin.

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.

Difficult Diagnosis of Fungal Arthritis After Arthroscopic Anterior Cruciate Ligament Reconstruction: A Case Report

CASE

An 18-year-old woman underwent arthroscopic anterior cruciate ligament reconstruction (ACLR) but developed recurrent knee effusion. At age 25 years, her right knee pain worsened, and radiographs revealed extensive bone loss. She was diagnosed with fungal (Candida parapsilosis) osteomyelitis by synovial fluid cultures. She underwent 2-stage surgery involving an amphotericin B-loaded cement spacer implantation and bone defect grafting. No recurrence of infection has been noted for 3 years postoperatively.

CONCLUSIONS

Fungal osteomyelitis may have few signs of local infection and often remains undiagnosed until bone loss occurs. Differential diagnosis should include this disease when there is recurrent knee effusion after ACLR.

Fungal Septic Knee Arthritis Caused by Aspergillus fumigatus following Anterior Cruciate Ligament Reconstruction

Postoperative infections after arthroscopic anterior cruciate ligament (ACL) reconstruction (ACLR) represent a rare but severe complication. An extremely rare case of Aspergillus septic arthritis in a 27-year-old patient following arthroscopic ACLR is reported. The patient presented with signs of knee infection 14 days after ACLR. Two consecutive arthroscopic debridements were performed, while eventually histopathology, cultures and multiplex PCR test revealed Aspergillus identified as A. fumigatus by mass spectrometry. The patient commenced long-term treatment with voriconazole. Fungal arthritis or osteomyelitis following ACLR has a mild local and general inflammatory reaction when compared to the bacterial ones. Nevertheless, such infections may lead to aggressive osseous destruction and necrosis. A high index of suspicion is of utmost importance for early detection, while microscopic, histological examination and multiplex PCR may be more helpful for the diagnosis than cultures since cultures are more time-consuming and may vary depending on different factors.

[Management algorithm for septic arthritis after anterior cruciate ligament reconstruction]

OBJECTIVE

To summarize the experience in the diagnosis and management of septic arthritis after anterior cruciate ligament reconstruction.

METHODS

A retrospective review was conducted of all the arthroscopic anterior cruciate ligament reconstructions performed at Department of Sports Medicine, Peking University Third Hospital between January 2001 and December 2020. In the study, 65 of 27 867 patients experienced postoperative septic arthritis. The incidence, presentation, laboratory results, treatment, and outcome of all the infected patients were analyzed. The experiences of diagnosis and management of septic arthritis after anterior cruciate ligament reconstruction were summarized.

RESULTS

A total of 27 867 anterior cruciate ligament reconstructions were performed at our department between January 2001 and December 2020. In the study, 65 (0.23%) patients were identified with postoperative septic arthritis. The most common symptoms of the infected patients were fever (38.7±0.5) ℃, knee swelling, pain, and restricted motion. The mean peripheral white blood cell count (WBC) was (9.2±2.6)×10⁹/L (range 4.2×10⁹/L-19.4×10⁹/L), with (72.5±6.3) % (range 54.9%-85.1%) polymorphonuclear neutrophils (N). The mean erythrocyte sedimentation rate (ESR) was (59.9±24.1) mm/h (range 9-108 mm/h), C-reactive protein (CRP) was (10.9±5.7) mg/dL (range 1.2-30.8 mg/dL), and fibrinogen (FIB) level was (7.0±1.6) g/L (range 3.7-10.8 g/L). All of the laboratory results were statistically higher in the infection group compared with the normal postoperative group (P＜0.001). The synovial white blood cell count (SWBC) of aspirated knee joint fluid was (45.0±29.8)×10⁹/L (range 7.1×10⁹-76.5×10⁹/L). Polymorphonuclear cell percentage (PMNC) was (90.27±7.86) % (range 60%-97%). In the study, 45 patients (69.2%) had positive aspirate cultures. Microbiology showed coagulase-negative Staphylococcus (CNS) and Staphylococcus aureus (SA) were the most common bacterium (34 cases and 7 cases, individually). There were 26 methicillin-resistant Staphylococcus. Both conservative (16 patients) and operative (49 patients) treatments were effective, but conservative group had a longer recovery time (5.6 d vs. 1.6 d, P=0.042).

CONCLUSION

Septic arthritis after arthroscopic anterior cruciate ligament reconstruction is a rare but potentially devastating complication. The correct diagnosis relies on synovial fluid analysis and bacterial culture. Our proposed treatment protocol is arthroscopic debridement and antibiotic therapy as quickly as possible.

Does Vancomycin Wrapping in Anterior Cruciate Ligament Reconstruction Affect Tenocyte Activity In Vitro?

Knee septic arthritis is a devastating complication following anterior cruciate ligament (ACL) reconstruction. To prevent this issue, intraoperative soaking of ACL grafts with vancomycin is often performed before implantation. Although vancomycin cytotoxicity has been reported several times, little is known about its biological effect on tenocytes. The aim of this study was to evaluate the in vitro effects of vancomycin on human primary tenocytes (hTCs). hTCs were isolated from hamstring grafts of four patients undergoing ACL reconstruction. After expansion, hTCs were treated with different concentrations of vancomycin (0, 2.5, 5, 10, 25, 50 and 100 mg/mL) for 10, 15, 30 and 60 min. In vitro cytotoxicity was evaluated measuring metabolic activity, cell toxicity, and apoptosis. hTC metabolic activity was affected starting from 10 mg/mL vancomycin and decreased markedly at 100 mg/mL. Cell viability remained unaffected only at a concentration of 2.5 mg/mL vancomycin. Vancomycin cytotoxicity was detected from 10 mg/mL after 15 min and at all higher concentrations. Cells died when treated with concentrations higher than 5 mg/mL. The use of this antibiotic on tendons to prevent infections could be useful and safe for resident cells if used at a concentration of 2.5 mg/mL for up to 1 h of treatment.

A More Positive Culture by Resin-containing Media Usage after Suspicious Arthroscopic Infections in Patients Receiving Antimicrobial Therapy

BACKGROUND

Although infections following arthroscopic surgery of cruciate ligament and meniscus are uncommon, they have potentially serious consequences for the graft and articular cartilage. This study aimed to investigate the efficacy of correct sampling and appropriate media, especially resin-containing media, for the detection of infections in patients receiving antibiotics under suspicion of joint infection after arthroscopic anterior cruciate ligament (ACL) and meniscal surgery. In such cases, proper sampling and the use of suitable culture media that cause the neutralization of antibiotics are very effective in isolating microorganisms from the patient samples and positive cultures.

METHODS

In total, 10 patients who had received antibiotics with suspected knee infection after arthroscopic ACL and meniscal surgery were identified after referral to surgeons during a period of 10 months and investigated in this study. The sample collection, culture on various media (i.e., resin-containing culture media), microbiological tests, and antibiotic susceptibility tests were performed in this study. The amplification of the mecA gene using PCR assay was accomplished for methicillin-resistant staphylococcus strains.

RESULTS

This study was conducted on 10 patients who underwent arthroscopic procedures and had received antibiotics. Overall, joint fluid and tissue culture were positive in 60% of the patients. The resin-containing media revealed a trend toward increased detection of bacteria. Coagulase-negative staphylococcus strains were the most frequently isolated bacteria in arthroscopic ACL surgery infections. Out of five methicillin-resistant staphylococcus strains, four strains were found that were resistant to cefoxitin and positive-mecA designated as methicillin-resistant strains. Except for one case, the rest of the staphylococcal strains were resistant to methicillin but susceptible to vancomycin.

CONCLUSION

Despite uncommon and low percentage of infections after arthroscopic ACL and meniscal surgery, the results of our study showed that correct sampling, appropriate cultures, especially aerobic and anaerobic resin-containing media, and microbiological testing remained useful and valuable for diagnosing bacterial infections.

Surgeon practice patterns for pre-soaking ACL tendon grafts in vancomycin: a survey of the ACL study group

PURPOSE

To survey members of The ACL study group to determine the current practice patterns surrounding the technique of pre-soaking ACL grafts in vancomycin.

METHODS

A web-based questionnaire was distributed to members of the ACL Study Group. Questions included the use of vancomycin solution for graft soaking during ACL reconstruction, their protocol for soaking the graft, vancomycin concentration utilized, graft choices, and concerns with the technique.

RESULTS

Sixty-six (57%) ACL surgeons completed the survey. Approximately one-third (37.9%) of respondents currently pre-soak their ACL grafts in vancomycin prior to implantation, with 60% of these surgeons being from Europe. Seventy-six percent have adopted this practice within the past 5 years. The majority of surgeons wrap the graft in a vancomycin-soaked gauze prior to implantation (56%), soak for a variable amount of time before implantation (56%), use a concentration of 5 mg/mL (68%), and soak hamstring grafts (92%). Concerns included the mechanical properties of the graft (35%), cost of vancomycin (23%), availability (12%), and antibiotic resistance (9%).

CONCLUSION

This survey demonstrates that 37.9% of ACL study group members currently utilize vancomycin to pre-soak ACL tendon grafts as a means to decrease post-operative infection risk, with the majority of surgeons having implemented this practice within the past 5 years. The biggest concern towards using vancomycin was the mechanical properties of the graft after soaking.

LEVEL OF EVIDENCE

IV.

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.

Significantly Lower Infection Risk for Anterior Cruciate Ligament Grafts Presoaked in Vancomycin Compared With Unsoaked Grafts: A Systematic Review and Meta-analysis

PURPOSE

To compare postoperative infection rates following ACL reconstruction performed with grafts presoaked in vancomycin versus those without vancomycin.

METHODS

A systematic review was performed using PRISMA guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for therapeutic level I to III studies that compared outcomes of presoaking ACL grafts with vancomycin versus without vancomycin in human patients. Included graft types were tendon autografts or allografts, and included studies documented infection with a minimum follow-up of 30 days. Postoperative infection rates and knee-specific patient-reported outcome scores were extracted from each study and compared between groups. Study methodological quality was analyzed using the Methodological Index for Non-Randomized Studies (MINORS) and Modified Coleman Methodology Score (MCMS). Infection rates and retear rates were pooled and weighted for meta-analysis using a random-effects model. All P values were reported with an α level of 0.05 set as significant.

RESULTS

The initial search yielded 144 articles (44 duplicates, 100 screened, 29 full-text review). Ten articles (21,368 subjects [7,507 vancomycin and 13,861 no vancomycin], 67% males, mean ± standard deviation age 29.5 ± 1.5 years) were included and analyzed. Eight of the 10 studies included only autografts, with 94.5% of grafts being hamstring autografts. Soaking grafts in vancomycin resulted in significantly fewer infections (0.013% versus 0.77%; odds ratio 0.07; 95% confidence interval 0.03, 0.18; P < .001). Only 2 studies included patient-reported outcomes, and both demonstrated no difference in International Knee Documentation Committee scores 1 year after surgery for patients with grafts presoaked in vancomycin versus without vancomycin.

CONCLUSIONS

Soaking ACL tendon grafts with vancomycin before implantation is associated with a nearly 15 times decrease in odds of infection compared with grafts not soaked in vancomycin. Few studies investigated patient-reported outcomes and retear rates after soaking ACL grafts in vancomycin.

LEVEL OF EVIDENCE

III, systematic review of level III studies.

Salmonella infection after anterior cruciate ligament reconstruction: A case report

BACKGROUND

Infections after anterior cruciate ligament reconstruction (ACLR) are rare. No cases of Salmonella infection have been described to our knowledge.

CASE SUMMARY

We describe a rare case of Salmonella infection in a 23-year-old patient following an ACLR. The patient presented with subacute septic arthritis, 26 d after a hamstring autograft ACLR. The pathogen, Salmonella enterica typhimurium was isolated by bacteriological sampling of the first arthroscopic lavage. Two arthroscopic lavages were required, with intravenous antibiotic therapy for two weeks with cefotaxime and ciprofloxacin, followed by oral antibiotics with amoxicillin and ciprofloxacin for a total duration of three months. This approach treated the infection but two years after the septic arthritis, faced with ongoing knee instability due to graft damage, a revision ACLR with a bone-tendon-bone graft was performed. At the last follow-up, full range of knee motion had been achieved and sports activities resumed.

CONCLUSION

Infection after ACLR is rare and requires an early diagnosis and management in order to treat the infection and prevent arthritis-related joint cartilage destruction and damage to the graft.

Inadvertent Debridement of the Medial Patellofemoral Ligament Following Arthroscopic Knee Surgery for Infection: A Case Report

Introduction

Arthroscopic debridement of the knee is usually considered a safe procedure. There are no case reports of medial patellofemoral ligament (MPFL) injury leading to habitual dislocation of the patella following this procedure in the literature.

Case Presentation

A 35-year-old male presented with complaints of habitual dislocation of the left patella, which he noticed after multiple arthroscopic surgeries of the left knee performed elsewhere. He had a history of septic arthritis of the knee following anterior cruciate ligament reconstruction, for which he underwent arthroscopic debridement of the knee twice. After a detailed evaluation, we noticed MPFL medial patellofemoral ligament injury.

Conclusion

The MPFL medial patellofemoral ligament injury occurred as a result of extensive resection of the medial joint capsule while operating for septic arthritis. This rare grave surgical complication emphasizes the care one should take during arthroscopic debridement of the knee.

Mucormycosis osteomyelitis after anterior cruciate ligament reconstruction: treatment and outcomes of 21 reported cases

Aims

Our purpose was to describe an unusual series of 21 patients with fungal osteomyelitis after an anterior cruciate ligament reconstruction (ACL-R).

Methods

We present a case-series of consecutive patients treated at our institution due to a severe fungal osteomyelitis after an arthroscopic ACL-R from November 2005 to March 2015. Patients were referred to our institution from different areas of our country. We evaluated the amount of bone resection required, type of final reconstructive procedure performed, and Musculoskeletal Tumor Society (MSTS) functional score.

Results

A total of 21 consecutive patients were included in the study; 19 were male with median age of 28 years (IQR 25 to 32). All ACL-R were performed with hamstrings autografts with different fixation techniques. An oncological-type debridement was needed to control persistent infection symptoms. There were no recurrences of fungal infection after median of four surgical debridements (IQR 3 to 6). Five patients underwent an extensive curettage due to the presence of large cavitary lesions and were reconstructed with hemicylindrical intercalary allografts (HIAs), preserving the epiphysis. An open surgical debridement was performed resecting the affected epiphysis in 15 patients, with a median bone loss of 11 cm (IQR 11.5 to 15.6). From these 15 cases, eight patients were reconstructed with allograft prosthesis composites (APC); six with tumour-type prosthesis (TTP) and one required a femoral TTP in combination with a tibial APC. One underwent an above-the-knee amputation. The median MSTS functional score was 20 points at a median of seven years (IQR 5 to 9) of follow-up.

Conclusion

This study suggests that mucormycosis infection after an ACL-R is a serious complication. Diagnosis is usually delayed until major bone destructive lesions are present. This may originate additional massive reconstructive surgeries with severe functional limitations for the patients.

Level of evidence: IV

Cite this article: Bone Joint Open 2020;2(1):3–8.

Post-operative septic arthritis after arthroscopy: modern diagnostic and therapeutic concepts

PURPOSE

Septic arthritis is a significant complication following arthroscopic surgery, with an estimated overall incidence of less than 1%. Despite the low incidence, an appropriate diagnostic and therapeutic pathway is required to avoid serious long-term consequences, eradicate the infection, and ensure good treatment outcomes. The aim of this current review article is to summarize evidence-based literature regarding diagnostic and therapeutic options of post-operative septic arthritis after arthroscopy.

METHODS

Through a literature review, up-to-date treatment algorithms and therapies have been identified. Additionally, a supportive new algorithm is proposed for diagnosis and treatment of suspected septic arthritis following arthroscopic intervention.

RESULTS

A major challenge in diagnostics is the differentiation of the post-operative status between a non-infected hyperinflammatory joint versus septic arthritis, due to clinical symptoms, (e.g., rubor, calor, or tumor) can appear identical. Therefore, joint puncture for microbiological evaluation, especially for fast leukocyte cell-count diagnostics, is advocated. A cell count of more than 20.000 leukocyte/µl with more than 70% of polymorphonuclear cells is the generally accepted threshold for septic arthritis.

CONCLUSION

The therapy is based on arthroscopic or open surgical debridement for synovectomy and irrigation of the joint, in combination with an adequate antibiotic therapy for 6-12 weeks. Removal of indwelling hardware, such as interference screws for ACL repair or anchors for rotator cuff repair, is recommended in chronic cases.

LEVEL OF EVIDENCE

IV.

Trauma and femoral tunnel position are the most common failure modes of anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To improve outcomes of anterior cruciate ligament reconstruction (ACLR), it is important to understand the reasons for failure of this procedure. This systematic review was performed to identify current failure modes of ACLR.

METHODS

A systematic search was performed using PubMed, EMBASE, Cochrane, and annual registries for ACLR failures. Studies were included when failure modes were reported (I) of ≥ 10 patients and (II) at a minimum of two-year follow-up. Modes of failure were also compared between different graft types and in femoral tunnel positions.

RESULTS

This review included 24 cohort studies and 4 registry-based studies (1 level I, 1 level II, 10 level III, and 16 level IV studies). Overall, a total of 3657 failures were identified. The most common single failure mode of ACLR was new trauma (38%), followed by technical errors (22%), combined causes (i.e. multiple failure mechanisms; 19%), and biological failures (i.e. failure due to infection or laxity without traumatic or technical considerations; 8%). Technical causes also played a contributing role in 17% of all failures. Femoral tunnel malposition was the most common cause of technical failure (63%). When specifically looking at the bone-patellar tendon-bone (BPTB) or hamstring (HT) autografts, trauma was the most common failure mode in both, whereas biological failure was more pronounced in the HT group (4% vs. 22%, respectively). Technical errors were more common following transtibial as compared to anteromedial portal techniques (49% vs. 26%).

CONCLUSION

Trauma is the single leading cause of ACLR failure, followed by technical errors, and combined causes. Technical errors seemed to play a major or contributing role in large part of reported failures, with femoral tunnel malposition being the leading cause of failure. Trauma was also the most common failure mode in both BPTB and HT grafts. Technical errors were a more common failure mode following transtibial than anteromedial portal technique.

LEVEL OF EVIDENCE

IV.

The use of vancomycin-soaked wrapping of hamstring grafts to reduce the risk of infection after anterior cruciate ligament reconstruction: An early experience in a district general hospital

Introduction

The purpose of the study was to investigate whether pre-soaked hamstring graft with a solution of vancomycin followed by the ‘vancomycin wrap’ provides an effective way to reduce the risk of post-operative infection. We hypothesized that with the addition of the ‘vancomycin wrap’ there would be a significant reduction in the risk of post-operative infection.

Methods

A retrospective review of data collected on 305 consecutive patients who underwent anterior cruciate ligament reconstruction (ACLR) with hamstring autograft from April 2012 to March 2019. In the initial 4-year period, 185 patients (group 1) underwent ACLR with pre-operative intravenous antibiotic. In the subsequent 3-year period, 120 patients underwent ACLR with vancomycin pre-soaked graft together with pre-operative intravenous antibiotic before tourniquet inflation. After graft harvest, the grafts were soaked into a 5 mg/ml vancomycin solution for 1 min. The graft was then fastened within the graft sizing tube and wrapped by a sterile gauze saturated with the vancomycin solution beforehand.

Results

A total of 3 culture-positive joint infection were documented (1.6%) in group I, requiring arthroscopic debridement. In group 2 no infection (0%) was recorded.

Conclusions

We proposed a safe, simple and easy-to-do method to reduce the risk of such complication.

Prophylactic vancomycin soaking of hamstring autograft is effective to reduce the infection rate in this series compared with pre-operative antibiotic alone.

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.

Presoaking of Semitendinosus Graft With Vancomycin Does Not Alter Its Biomechanical Properties: A Biomechanical In Vitro-Controlled Study Using Graft From Living Donors

PURPOSE

To compare the biomechanical properties of human semitendinosus graft presoaked with or without vancomycin under a load to failure tensile test.

METHODS

Thirty semitendinosus grafts harvested during anterior cruciate ligament reconstruction were included. These were dissected equally into 2 halves and subsequently randomly allocated to a vancomycin group and to a control group. A digital caliper was used to precisely measure each samples thickness, length, and width. For the vancomycin group, samples were presoaked in a solution of 5 mg/mL vancomycin for a duration of 10 minutes and the control group samples were presoaked in a physiological serum equally for 10 minutes. Mechanical testing was performed on a universal testing machine (Instron 5566-A) after a preconditioning of 10 cycles of 1 mm extension and a progression of 10 mm/min to failure for each sample. The stress-strain curve was obtained to determine the elastic modulus (Young's modulus), the ultimate tensile stress, the ultimate tensile elongation (UTE) before failure and the elasticity limit.

RESULTS

For the control group, the average Young's modulus value was 4.8 ± 0.8, the average UTS was 25.2 ± 5.2 MPa, the average percentage of UTE was 78 ± 17%, and the average elasticity limit value was 17.3 ± 5.3 MPa. For the vancomycin group, the average Young's modulus value was 4.7 ± 0.9, the average ultimate tensile stress was 24.1 ± 6.1 MPa, the average percentage of UTE was 82 ± 14%, and the average elasticity limit value was 18.5 ± 5.9 MPa. No significant difference was observed between the 2 groups for all investigated parameters.

CONCLUSIONS

Presoaking of human semitendinosus graft with vancomycin does not alter its biomechanical properties.

CLINICAL RELEVANCE

This study demonstrates that vancomycin presoaking used to prevent post-anterior cruciate ligament reconstruction septic arthritis does not affect immediate biomechanical properties of semitendinosus tendons.

Clinical Outcomes After Anterior Cruciate Ligament Injury: Panther Symposium ACL Injury Clinical Outcomes Consensus Group

A stringent outcome assessment is a key aspect of establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. To establish a standardized assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, Pennsylvania, USA, in June 2019. The aim was to establish a consensus on what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used, and at what follow-up time those outcomes should be assessed. The group reached consensus on 9 statements by using a modified Delphi method. In general, outcomes after ACL treatment can be divided into 4 robust categories: early adverse events, patient-reported outcomes (PROs), ACL graft failure/recurrent ligament disruption, and clinical measures of knee function and structure. A comprehensive assessment after ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained reinjuries, validated knee-specific PROs, and health-related quality of life questionnaires. In the midterm to long-term follow-up, the presence of osteoarthritis should be evaluated. This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

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.

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.

Clinical outcomes after anterior cruciate ligament injury: panther symposium ACL injury clinical outcomes consensus group

PURPOSE

A stringent outcome assessment is a key aspect for establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. The aim of this consensus statement was to establish what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used and at what follow-up time those outcomes should be assessed.

METHODS

To establish a standardized approach to assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, PA; USA, in June 2019. The group reached consensus on nine statements by using a modified Delphi method.

RESULTS

In general, outcomes after ACL treatment can be divided into four robust categories-early adverse events, patient-reported outcomes, ACL graft failure/recurrent ligament disruption and clinical measures of knee function and structure. A comprehensive assessment following ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained re-injuries, validated knee-specific PROs and Health-Related Quality of Life questionnaires. In the mid- to long-term follow-up, the presence of osteoarthritis should be evaluated.

CONCLUSION

This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

LEVEL OF EVIDENCE

V.

Professional Athletes Are at Higher Risk of Septic Arthritis After Anterior Cruciate Ligament Reconstruction: An Analysis of 4421 Consecutive Patients Including 265 Elite Athletes From the SANTI Study Group

BACKGROUND

Professional athletes are reported to be at greater risk of septic arthritis (SA) after anterior cruciate ligament reconstruction (ACLR) than the nonprofessional population. However, this finding has been controversial, and confusion has arisen in the literature owing to the underpowering of previous studies.

PURPOSE/HYPOTHESIS

The purpose was to report the differences in the rate of SA after ACLR in a large series of patients and to perform pooled data analysis including previously published studies. The hypothesis was that professional athletes have a significantly higher risk of SA than nonprofessional athletes.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective analysis of prospectively collected data was performed. Patients who underwent ACLR between January 2009 and July 2017 (with a minimum follow-up of 12 months) were considered for study eligibility. The rate of SA was determined, and multivariate analysis was used to evaluate potentially important risk factors, including participation in professional sport. Furthermore, a literature search was performed, and data were extracted from all identified relevant studies. A pooled data analysis was performed to determine differences in the risk of SA between professional and nonprofessional populations.

RESULTS

The current series comprised 4421 anterior cruciate ligament surgical procedures with 265 professional athletes. There were 15 cases of SA diagnosed over the study period (0.34%; 95% CI, 0.19%-0.56%). Ten cases occurred in professional athletes (3.8%; 95% CI, 1.82%-6.83%). The percentage of SA was 0.12% (95% CI, 0.04%-0.28%) in the nonprofessional population. Being a professional athlete was associated with a significantly increased risk of SA after ACLR (odds ratio, 21.038; 95% CI, 6.585-75.789; P < .0001). This finding was confirmed in the pooled data analysis comprising 11,416 patients including 1118 professional athletes (odds ratio, 5.03; 95% CI, 1.17-21.61).

CONCLUSION

Professional athletes are at greater risk of SA after ACLR than nonprofessional athletes. The results of previous studies may have been conflicting owing to underpowering. The current study confirms the elevated risk by using a large clinical series and pooled data analysis to avoid the limitations of previous studies.

Arthroscopic irrigation and debridement is associated with favourable short-term outcomes vs. open management: an ACS-NSQIP database analysis

PURPOSE

Septic arthritis of the knee is an orthopaedic emergency that is associated with marked morbidity and can potentially be life threatening. Surgical debridement can be performed either arthroscopically or via an arthrotomy. The aim of this study was to compare the 30-day complications and adverse outcomes between the two procedures.

METHODS

Patients with a diagnosis of septic arthritis of the knee between 2011 and 2015 were identified using the ACS-NSQIP database. The study population included 695 patients, who had knee septic arthritis and underwent either an arthroscopic irrigation or debridement (I&D) (n = 464) or open irrigation and debridement (n = 231). Preoperative data included demographics, independent functional status, and comorbidities. Outcomes of interest included wound complications, infectious complications, cardiovascular events, hospital readmissions, and reoperations, or any of the previous adverse events.

RESULTS

Both cohorts were similar in most baseline characteristics. Bleeding requiring transfusion was significantly lower in the arthroscopic (n = 13; 3.6%) compared to the open procedure (n = 31; 13.4%; p = 0.0001). Home discharge was significantly higher in the arthroscopic irrigation and debridement group (n = 310; 67.5%) compared to the open group (n = 126; 55%; p = 0.0013). The overall incidence of adverse events was lower in the arthroscopic group (n = 158; 34%) compared to the open group (n = 112; 49%; p = 0.0002). There was no difference in rates of infectious complications, thromboembolic events, hospital readmission, reoperation, or mortality between the groups. Open irrigation and debridement was associated with higher risk of bleeding requiring transfusion (OR = 3.79; 95% CI: 2.02-7.13; p = 0.0001), higher risk of incidence of adverse events (OR = 1.46; 95% CI: 1.02-2.08; p = 0.039), and lower home discharge (OR = 3.79; 95% CI: 2.02-7.13; p = 0.0001) within 30 days after the procedure.

CONCLUSION

Arthroscopic irrigation and debridement demonstrated favourable short-term outcomes. Patients who underwent arthroscopic irrigation and debridement had lower rates of blood transfusions, lower rates of adverse events, and higher home discharge rates compared to open irrigation and debridement. This study is the largest analysis comparing arthroscopic vs. open irrigation and debridement in a national database sample. These findings conclude that arthroscopic debridement can be an alternative first-line option in managing septic arthritis.

LEVEL OF EVIDENCE

III.

Vancomycin-soaked wrapping of harvested hamstring tendons during anterior cruciate ligament reconstruction. A review of the 'vancomycin wrap'

The practice of 'vancomycin wrapping' of harvested hamstring autografts during Anterior Cruciate Ligament Reconstruction (ACLR) surgery has gathered recent interest. This practice involves the wrapping of harvested grafts in a vancomycin-soaked swab during the preparatory phase. Different techniques are observed, and a small number of studies have shown that pre-soaking hamstring ACLR grafts in this manner dramatically reduces the post-surgical infection rate compared with standard intravenous antibiotic prophylaxis alone. However, the literature surrounding this practice is surprisingly limited and thus the basis and rationale of the 'vancomycin wrap' has established itself largely without question. The exact popularity of this practice is difficult to establish but there has been increasing disclosure of its efficacy in reducing post-operative infection in ACLR since 2012. We provide a synopsis of the current literature surrounding vancomycin and its use in 'wraps' in ACLR to help apprise the surgeon of the nature of infection in ACLR, the rationale for vancomycin, whilst considering evidence to support alternatives and discussing potential ramifications for future practice.

Professional Athletes Are Not at a Higher Risk of Infections After Anterior Cruciate Ligament Reconstruction: Incidence of Septic Arthritis, Additional Costs, and Clinical Outcomes From the French Prospective Anterior Cruciate Ligament Study (FAST) Cohort

BACKGROUND

The rate of septic arthritis in the knee after anterior cruciate ligament (ACL) reconstruction varies in the literature but is generally less than 1%. It has been reported to be higher in professional athletes (5.7%).

PURPOSE

The primary goal was to evaluate the rate of septic arthritis after ACL reconstruction in professional athletes compared with other patients. The secondary goals were to analyze the risk factors; increased cost of infections; return to sport, satisfaction, and functional results at 1-year follow-up; and resolution rate of infections at final follow-up.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This retrospective analysis of prospective data included a continuous series of patients who underwent isolated ACL reconstruction between 2012 and 2016. The main outcome criterion was the development of intra-articular infections in the operated knee. An infection was suggested clinically (knee pain with fever and/or chills) and confirmed bacteriologically in deep tissue samples obtained during revision surgery. All infected patients underwent an emergency reoperation with lavage and debridement along with dual antibiotic therapy first by an intravenous route and then orally for 6 weeks.

RESULTS

A total of 1809 of 1859 patients included in the cohort during this period fulfilled inclusion criteria; there were 1632 (90.2%) who underwent primary reconstruction and 177 (9.8%) who underwent revision. The series included 1249 (69%) men and 560 (31%) women, with a mean age of 29.1 ± 9.8 years. Ninety-eight percent of the patients participated in a sport, including 90 (5.0%) at a professional level and 712 (39.4%) competitively. Septic arthritis of the knee developed after a mean 15.7 ± 5.5 days in 7 (0.38%) patients: 5 of 1632 (0.31%) who underwent primary reconstruction and 2 of 177 (1.13%) who underwent revision. Septic arthritis did not develop in any professional or competitive athletes; all affected patients were recreational athletes ( P = .02). The risk factors identified for the development of septic arthritis on multivariate analysis were prior knee surgery (odds ratio [OR], 15; P = .002) and hemarthrosis during the immediate postoperative period (OR, 127.2; P = .002). There were no recurrent infections after a mean follow-up of 2.8 ± 1.2 years.

CONCLUSION

None of the professional athletes in this cohort had septic arthritis after ACL reconstruction. There are no particular precautions to be taken in this population. The risk factors identified for the development of septic arthritis on multivariate analysis were prior knee surgery and hemarthrosis during the immediate postoperative period. Similar to all studies published on the subject, there were very few infected patients, which limits the identification of risk factors.

REGISTRATION

NCT02511158 (ClinicalTrials.gov identifier).

Septic arthritis after arthroscopic posterior cruciate ligament and multi-ligament reconstructions is rare and can be successfully treated with arthroscopic irrigation and debridement: analysis of 866 reconstructions

PURPOSE

The purpose of this study was to determine the incidence of septic arthritis following arthroscopic posterior cruciate ligament (PCL) and multi-ligament reconstructions, and to evaluate a treatment regime with sequential arthroscopic irrigation and debridement procedures combined with antibiotic therapy that is focused on retention of the graft.

METHODS

Between 2004 and 2016 a total of 866 PCL reconstructions and multi-ligament reconstructions were performed at our institution (408 isolated PCL reconstructions, 458 combined reconstructions). Medical charts of all cases were retrospectively reviewed with regard to the occurrence of septic complications. These cases were analysed with special focus on clinical management, number of reoperations and if the grafts were retained. Further, microbiological findings, postoperative clinical course and available clinical outcome data were evaluated.

RESULTS

Four cases of septic arthritis (0.5%) were identified (follow-up rate 96.5%): two following isolated PCL reconstruction (0.5%), and two following multi-ligament reconstruction (0.4%), respectively. Septic arthritis was successfully treated in all cases with a mean of 2.5 ± 2.4 irrigation and debridement procedures (1-6). In one case of isolated PCL reconstruction, the graft was resected within the fifth irrigation and debridement due to septic loosing of the femoral fixation. All other grafts were retained. With regard to the outcome, all patients were subjectively satisfied with good stability (stress radiographs) in cases of retained grafts.

CONCLUSION

Postoperative septic arthritis after arthroscopic PCL and complex knee ligament reconstructions is a rare but serious complication. Arthroscopic graft-retaining treatment is recommended, as it is established in ACL surgery. Graft retention can be expected in the majority of the cases.

LEVEL OF EVIDENCE

Case series, Level 4.

Anterior cruciate ligament reconstruction complicated by Propionibacterium acnes infection: case series

Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed orthopaedic procedures. While generally successful, failure resulting in revision surgery is reported to be between 1.9 - 4.9%. However, when not related to traumatic re-injury, failure mechanism is poorly understood. One potential but understudied mechanism of ACL reconstruction failure is infection. We describe three patients with previous ACL reconstructions who later developed infection with Propionibacterium acnes. Two cases presented with knee pain and swelling, and one presented with instability. While only two of the three cases received antibiotic treatment, all three cases were free of knee and infectious symptomatology at most recent follow-up. P. acnes infection may represent one potential mechanism for biologic failure of ACL reconstruction and anaerobic operative cultures may be used to identify its presence.