Tubercular infection after arthroscopic anterior cruciate ligament reconstruction

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.

A Systematic Review of Nontuberculous Mycobacterium Infection Following Anterior Cruciate Ligament Reconstruction

Although infection following anterior cruciate ligament (ACL) reconstruction is rare, these cases have potentially catastrophic ramifications. Nontuberculous mycobacteria (NTM) are ubiquitous, located in the water supply and soil. Our objective was to review the literature to characterize NTM infection following ACL reconstruction.

Methods

A database search was performed for arthroscopic ACL reconstructions that resulted in a postoperative diagnosis of NTM infection.

Results

The literature search returned 6 case reports that met the inclusion criteria. The initial postoperative presentation occurred after 3 to 52 weeks, which is consistent with reports of postoperative NTM infection.

Conclusions

The common indolent course of NTM infection hinders prompt diagnosis and treatment. Organism susceptibility testing is crucial for effective treatment and limiting unnecessary antibiotic exposure.

Clinical Relevance

The duration of medical treatment for NTM infection is 4 to 6 months, depending on the severity of disease and species. Based on the aggregate literature, we recommend removal of local implants if the infection is localized and without articular involvement. However, in cases of articular involvement, all fixation and graft material should be removed.

[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.

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.

Tuberculous osteomyelitis of tibial diaphysis following saphenous vein graft harvest for coronary artery bypass: a case report

Tuberculosis in the tibial diaphysis following saphenous vein graft harvest for coronary artery bypass grafting has not been reported, to the best of authors' knowledge. We report the first such clinical case in view of its clinical rarity and as a complication of the simple procedure like saphenous vein graft harvest.

Knee and Leg Injuries

Knee and leg injuries are extremely common presentations to the emergency department. Understanding the anatomy of the knee, particularly the vasculature and ligamentous structures, can help emergency physicians (EPs) diagnose and manage these injuries. Use of musculoskeletal ultrasonography can further aid EPs through the diagnostic process. Proper use of knee immobilizers can also improve long-term patient outcomes.

Uncommon Complications after Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACL-R) is a common surgical procedure, with good outcome in 75 to 97% of the cases. However, different complications have been described including infection, hemarthrosis, deep vein thrombosis (DVT), and pulmonary embolism (PE) with a rate ranging from 1 to 15%. There are few case reports in the literature describing rare complications after ACL-R and they can be divided into: (1) complications related to the fixation device (rupture, migration); (2) fractures (tibial or femoral side); (3) infections due to uncommon bacteria, mycobacterium, and mycosis; (4) rare vascular injuries; (5) nerve injuries; and (6) other rare complications. In case of fixation device rupture or migration, device removal can be easy but the diagnosis may be challenging. Patellar fracture after ACL-R may be related to harvesting and it is not uncommon. Conversely, femoral or tibial fractures are most frequently due to bone weakness related to bone tunnels. Some rare infections related to uncommon bacteria or mycosis are also described with potentially devastating joint damage. Popliteal artery injuries are uncommon in ACL-R but minor vessels damages are described with possible severe consequences for patients. Injuries to the infrapatellar branch of the saphenous nerve are not uncommon in ACL-R. However, there are few case reports also describing injuries to the saphenous nerve, the common peroneal nerve and the sciatic nerve. The aim of this paper is to review the literature describing uncommon complications after ACL-R, giving some more information about diagnosis and treatment.

Incidence, Risk Factors, and Management of Infection Following Anterior Cruciate Ligament Reconstruction Surgery

BACKGROUND

Infection after anterior cruciate ligament reconstruction surgery (ACLRS) is a rare complication. Although there are number of studies from various Caucasian population but only few studies are available from Asian population. The aim of the study is to assess the incidence, risk factors and, clinical outcome using our treatment protocol.

MATERIALS AND METHODS

Out of 1468 arthroscopic ACLRS, 26 patients with clinical suspicion of infection were critically analysed in terms of laboratory reports of arthrocentesis, erythrocyte sedimentation rate, C-reactive protein and risk factors such as the type of graft, gender, diabetes mellitus, smoking, intraarticular steroid injection, and obesity. At final followup, all these patients were evaluated using visual analog scale (VAS), Lysholm knee score, and Tegner activity level.

RESULTS

In nine patients, culture did not show any growth and they showed improvement with arthrocentesis and oral antibiotics. These patients were labeled as suffering from aseptic effusion. In the remaining 17 patients, there was no clinical improvement or instead worsening of symptoms after arthrocentesis and oral antibiotics. These patients were labeled as suffering from an infection and underwent surgical debridement along with administration of injectable antibiotics. The history of intraarticular steroid injection before ACLRS was a significant risk factor for developing infection (P = 0.001). At mean followup of 2.8 years, mean VAS improved to 1.18 ± 0.99 from 6.2 ± 2.3. The mean Lysholm knee score and Tegner's activity level at the final followup were 79.2 ± 10.52 and 4.8 ± 2.30, respectively.

CONCLUSION

The incidence of infection was 1.2% (17/1468). The step-ladder approach of differentiating between aseptic effusion and infection and accordingly, following a treatment protocol, i.e., oral antibiotics alone or surgical debridement along with injectable antibiotics or additional debridement of graft in refractory patients, yielded satisfactory results.

Tubercular infection after arthroscopic rotator cuff repair

Tubercular septic arthritis after shoulder arthroscopy has not been reported in the English literature to our knowledge. A case of Tubercular septic arthritis of the shoulder following arthroscopic rotator cuff repair is presented. The sinus and the wound healed well, and laboratory parameters returned to normal, which suggests that the infection was well controlled with the treatment follow-up of 1 year. But the functional score was poor due to repeated surgeries; long-standing infection and the arthritic changes developed. Tubercular infection can occur after arthroscopic shoulder surgery especially in healthcare workers in zones endemic for Tuberculosis. Level of evidence V.

Implant-associated mycobacterium tuberculosis infection following surgical management of fractures: a retrospective observational study

In this retrospective observational cohort study, we describe 17 patients out of 1775 treated for various fractures who developed mycobacterium tuberculosis (MTB) infection after surgery. The cohort comprised 15 men and two women with a mean age of 40 years (24 to 70). A total of ten fractures were open and seven were closed. Of these, seven patients underwent intramedullary nailing of a fracture of the long bone, seven had fractures fixed with plates, two with Kirschner-wires and screws, and one had a hemiarthroplasty of the hip with an Austin Moore prosthesis. All patients were followed-up for two years. In all patients, the infection resolved, and in 14 the fractures united. Nonunion was seen in two patients one of whom underwent two-stage total hip arthroplasty (THA) and the other patient was treated using excision arthoplasty. Another patient was treated using two-stage THA. With only sporadic case reports in the literature, MTB infection is rarely clinically suspected, even in underdeveloped and developing countries, where pulmonary and other forms of TB are endemic. In developed countries there is also an increased incidence among immunocompromised patients. In this paper we discuss the pathogenesis and incidence of MTB infection after surgical management of fractures and suggest protocols for early diagnosis and management.

Lessons learnt from an atypical mycobacterium infection post-anterior cruciate ligament reconstruction

Infections following anterior cruciate ligament reconstruction are rare, with no previous reports citing Mycobacterium abscessus as the culprit pathogen. A 22-year-old man presented twice over three years with a painful discharging sinus over his right tibia tunnel site necessitating repeated arthroscopy and washout, months of antibiotic therapy, and ultimately culminating in the removal of the implants. In both instances, M. abscessus was present in the wound cultures, along with a coinfection of Staphyloccocus aureus during the second presentation. Though rare, M. abscessus is an important pathogen to consider in postoperative wounds presenting with chronic discharging sinuses, even in healthy non-immunocompromised patients. This case illustrates how the organism can cause an indolent infection, and how the removal of implants can be necessary to prevent the persistence of infection. Coinfection with a second organism is not uncommon and necessitates a timely change in treatment regime as well.

Recommendations for the management of septic arthritis after ACL reconstruction

PURPOSE

To evaluate the current evidence for the management of septic arthritis after anterior cruciate ligament (ACL) reconstruction, the factors that affect the outcome after treatment and the retention of graft and implants.

METHODS

A systematic literature search of the PubMed database was performed on septic arthritis after ACL reconstruction. A total of 301 publications were initially identified, and 17 papers were found to fulfil the criteria to be included in the review.

RESULTS

There were 196 cases of septic arthritis after ACL reconstruction in over 30,000 ACL reconstructions, making the proportion of infection 0.6%. Most patients (114/123, 92.6%) had an acute or subacute infection at an average of 16.8 ± 10.5 days after ACL reconstruction. Coagulase-negative Staphylococci (CNS) was the most common organism (67/147, 45.6%) followed by Staphylococcus aureus (SA) (35/147, 23.8%); 86.9% underwent surgical treatment of which 92.8% had an average of 1.54 (up to 4) arthroscopic debridements. The group with SA infection had a higher graft removal rate (33.3%, p = 0.019), a longer antibiotic duration (35.4 days, p = 0.047) and a worse range of flexion (111.5°, p = 0.036) than the CNS group.

CONCLUSIONS

CNS was the most common organism in septic arthritis after ACL reconstruction followed by SA. For most authors, arthroscopic debridement combined with intravenous antibiotic therapy was the initial treatment of choice. Antibiotic therapy with or without multiple irrigations of the joint is not recommended based on the high failure rates. Delayed diagnosis of more than 7 days or SA infection required a longer duration of antibiotic therapy and increased the likelihood for graft removal and restricted range of motion. Fungal infection and tubercular infection had a high prevalence of late diagnosis and open debridement.

LEVEL OF EVIDENCE

Systematic review, Level IV.

C-reactive protein and erythrocyte sedimentation rate changes after arthroscopic anterior cruciate ligament reconstruction: guideline to diagnose and monitor postoperative infection

PURPOSE

The purposes of our study were to determine normative C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values from a retrospective review of patients with and without infection after anterior cruciate ligament (ACL) reconstruction and to determine CRP and ESR threshold levels that can serve as diagnostic indicators of infection. We also tried to draw a curve of CRP and ESR value changes after treatment of ACL infection to evaluate the response to treatment of the infection.

METHODS

A retrospective chart review was performed of arthroscopic ACL reconstruction patients from 2007 to 2008 (noninfection group) and all patients with postoperative intra-articular infection from 1997 to 2010 (infection group). We collected the CRP and ESR values on the third and fifth postoperative days in the noninfection group and before infection treatment and on the first, third, fifth, seventh, 10th, 14th, 21st, 28th, and 35th days after infection treatment in the infection group. Sensitivity, specificity, and Youden's index were calculated for different threshold values of CRP and ESR as predictors of infection. Receiver operator curves were obtained for CRP and ESR on the fifth postoperative day.

RESULTS

Of 122 patients, 83 had normal joints and 39 had septic joints. The mean CRP and ESR values in patients with septic joints were 101.9 mg/L and 57.1 mm/h, respectively, which were significantly higher than those in the noninfection group (P < .01). A CRP value of 41 mg/L and ESR value of 32 mm/h were the optimal thresholds to predict an infection, which had the highest Youden's index of all calculated values and had sensitivity values of 94.1% and 91.2%, respectively, and specificity values of 97.6% and 80.5%, respectively. The peak CRP level after infection treatment occurred earlier than the peak ESR level (first day v third day) and returned to normal more quickly (21st day v 28th day).

CONCLUSIONS

Both CRP and ESR were helpful in determining the presence of a normal or septic joint. The threshold values of 41 mg/L for CRP and 32 mm/h for ESR had the most optimal sensitivity and specificity. The peak CRP level occurred earlier than the peak ESR level after treatment of postoperative infection and returned to normal more quickly. In this study CRP was more useful than ESR to evaluate the response of infection to treatment.

LEVEL OF EVIDENCE

Level IV, diagnostic study.

Infection after arthroscopic anterior cruciate ligament reconstruction

Septic arthritis is a rare but potentially devastating complication of anterior cruciate ligament (ACL) reconstruction surgery. The purpose of this study was to provide an evidence-based summarization of the treatment and outcome of infection after ACL reconstruction with a pooled analysis of the reported cases. The authors conducted a systematic review of published studies that evaluated the outcome of septic arthritis after arthroscopic ACL reconstruction. A structured literature review of multiple databases referenced articles from 1950 to 2012. A total of 22,836 knees from 14 published studies were assessed. Postoperative septic arthritis occurred in 121 knees, with a pooled percentage of 0.5%. Mean duration of follow-up after ACL reconstruction was 53.6 months (range, 4-218 months). An average of 1.92 procedures (range, 1-5 procedures) were performed to eradicate the infection. The grafts were retained in 77% of cases. Postoperative intravenous antibiotics were used for at least 5 days (range, 5-90 days) after debridement. At final follow-up, mean postoperative Lysholm score was 80.2 (range, 23-100). No reinfection was observed in 121 patients. This study has helped to further elucidate the outcomes of infection after ACL reconstruction. Once an infection is encountered, culture-specific antibiotics and surgical joint irrigation with graft retention are recommended as initial treatment. Graft removal can be considered only for those infections resistant to initial treatment.

Arthroscopic irrigation and debridement in the treatment of septic arthritis after anterior cruciate ligament reconstruction

PURPOSE

To systematically review the literature and characterize the success and failure rates of arthroscopic irrigation and debridement (I & D) in the treatment of septic arthritis after anterior cruciate ligament (ACL) reconstructions. We also aimed to identify which variables affected the failure rate.

METHODS

Five databases (MEDLINE, Ovid, Medscape, Web of Science, and Google Scholar) were screened for clinical studies involving the treatment of septic arthritis after ACL reconstruction with arthroscopic I & D. A full-text review of eligible studies was conducted. Inclusion and exclusion criteria were applied to the searched studies. Failure of I & D was defined as the need for graft removal or revision ACL reconstructive surgery because of infection. Data from the selected studies were combined for statistical analyses to elucidate factors associated with the success or failure.

RESULTS

We identified 11 eligible studies involving 90 patients. These studies described the results of 90 arthroscopic I & D procedures with an overall success rate of 85.6%. Repeated I & D was necessary in 34.5% of patients. Removal of the graft with or without subsequent revision ACL reconstruction was reported in 13 (14.4%) cases. Statistical analysis showed that cases involving Staphylococcus aureus (P = .053), 2 or more I & D procedures (P = .029), and allografts (P < .0001) were at greater risk of failure.

CONCLUSIONS

Arthroscopic I & D with graft retention is an effective treatment for patients with septic arthritis after ACL reconstruction. Factors affecting the failure rate may include graft choice and organism virulence.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Infections in anterior cruciate ligament reconstruction

Context:

Anterior cruciate ligament (ACL) reconstruction is a safe, common, and effective method of restoring stability to the knee after injury, but evolving techniques of reconstruction carry inherent risk. Infection after ACL reconstruction, while rare, carries a high morbidity, potentially resulting in a poor clinical outcome.

Evidence Acquisition:

Data were obtained from previously published peer-reviewed literature through a search of the entire PubMed database (up to December 2012) as well as from textbook chapters.

Results:

Treatment with culture-specific antibiotics and debridement with graft retention is recommended as initial treatment, but with persistent infection, consideration should be given to graft removal. Graft type likely has no effect on infection rates.

Conclusion:

The early diagnosis of infection and appropriate treatment are necessary to avoid the complications of articular cartilage damage and arthrofibrosis.

Management of septic arthritis following anterior cruciate ligament reconstruction: a review of current practices and recommendations

Septic arthritis following anterior cruciate ligament reconstruction is a rare and potentially devastating complication that often leads to articular destruction and adverse clinical outcomes. Because of its rare occurrence, best practices for diagnosis and management have yet to be established. However, graft retention and favorable outcomes are possible with early diagnosis, surgical intervention, and appropriate antibiotic management. Clinicians must be familiar with the diagnostic criteria and management options for septic arthritis. Most patients require multiple procedures to effectively eradicate infection. When the original reconstructed graft cannot be salvaged, a staged anterior cruciate ligament reconstruction revision is required.

Skeletal muscle tuberculosis simultaneously involving multiple sites

Tuberculosis (TB) continues to be a public health problem in both developing and industrialized countries. TB of the skeletal muscle is very rare. We present a case of the simultaneous involvement of skeletal muscles in multiple sites in an 11-year-old immune-competent female patient. All physicians should have adequate knowledge of TB and awareness of its atypical presentations to ensure the proper management of such patients.

Elevated local TGF-β1 level predisposes a closed bone fracture to tuberculosis infection

Tuberculosis (TB) occurring after a closed bone fracture in the patient with no history of TB and no evidence of TB infection at the time of initial fracture is a rare entity. Transforming growth factor-beta 1 (TGF-β1) is a ubiquitous growth factor that is implicated in the regulation of the proliferation, differentiation, migration, and survival of many different cell types. Recent studies have demonstrated that the local level of TGF-β1 in bone is significantly elevated during fracture healing and TGF-β1 plays an important role in TB progression. Given the above background, we hypothesize that elevated local TGF-β1 level predisposes a closed bone fracture to TB infection. This was supported by conclusions drawn from literature reviews: (1) the local level of TGF-β1 in bone is significantly elevated during fracture healing; (2) TGF-β1 inhibits T lymphocyte activation; (3) TGF-β1 is a potent macrophage-deactivating molecule; (4) TGF-β1 suppresses the production and activity of some proinflammatory cytokines.

Clinical value of polymerase chain reaction in the diagnosis of joint tuberculosis by detecting the DNA of Mycobacterium tuberculosis

OBJECTIVE

To assess the clinical value of polymerase chain reaction (PCR) in the diagnosis and differential diagnosis of joint tuberculosis (TB).

METHODS

PCR was used blindly to detect the DNA of Mycobacterium tuberculosis (M.TB) in five specimens of M.TB, 5 of BCG, and 10 of other bacteria. Then, M. TB in 98 samples from patients with joint TB and 100 samples from patients with non-tubercular joint disorders were detected by PCR, acid-fast staining and culture,. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PCR were calculated. The χ2 test was used for statistical analysis of the frequency of various factors. At the same time, some problems with PCR were also systematically analyzed.

RESULTS

(1) In the "standard samples", both M. TB and BCG showed positive while other bacteria were negative. (2) In 98 cases from patients with joint TB, 81 were positive by PCR, 6 by acid-fast staining, and 17 by culture. In 100 cases from patients with non-tuberculous joint disorders, 9 were positive by PCR, and none by either acid-fast staining or culture. Sensitivity, specificity, accuracy, positive and negative predictive value of PCR were 82.65% (81/98), 91.00% (91/100), 86.87% (172/198), 90.00% (81/90) and 84.26% (91/108), respectively. (3) The positive rates for PCR, acid-fast staining and culture in detection of M. TB were 82.65% (81/98), 6.12% (6/98), and 17.34% (17/98), respectively. There were statistically significant differences between the three methods (P < 0.001). (4) The process of PCR is automatic, and can be completed within 3 to 6 hours, whereas 4 to 8 weeks are required for the conventional culture of M. TB.

CONCLUSION

PCR is a sensitive, specific, rapid, simple and minimally invasive method for detection of M. TB in samples from joint TB, and can play an important role in early and rapid diagnosis and differential diagnosis of joint TB. But it also has some limitations, such as false positivity and false negativity.

Knee and leg injuries

The knee plays a significant role in ambulation and the activities of daily living. During the course of these activities and its role in weight bearing, the knee is susceptible to a variety of different forces and the emergency physician should be familiar with the diagnosis and treatment of the injuries that result. In addition to following basic trauma protocols, thorough neurovascular and musculoskeletal examinations should be performed and supplemented with appropriate imaging. Emergency physicians should also consider recent developments in knee anatomy and function when evaluating the patient with an acutely injured knee.

Anterior cruciate ligament graft reconstruction: clinical, technical, and imaging overview

The anterior cruciate ligament (ACL) is one of the most frequently torn ligaments of the knee. With more than 100,000 ACL reconstructions performed yearly in the United States, evaluation of ACL grafts with magnetic resonance imaging is a common occurrence in daily clinical practice. Anterior cruciate ligament reconstructions vary from single bundle, double bundle, selective bundle, and physeal-sparing techniques. Complications of ACL graft reconstructions include graft tears, graft laxity, arthrofibrosis, and hardware failure or migration. This article offers a comprehensive review of ACL reconstruction for the consulting radiologist.