Identification and treatment of infected total hip arthroplasty

Mycobacterium fortuitum Prosthetic Joint Infection After Total Hip Arthroplasty: A Case Report

CASE

A 57-year-old man presented with a Mycobacterium fortuitum prosthetic joint infection (PJI) after right total hip arthroplasty refractory to the initial revision surgery and cement spacer placement. The patient was subsequently treated with 2-stage total joint arthroplasty revision surgery using an antibiotic-laden spacer customized to include meropenem and delayed reimplantation to allow for prolonged, systemic antimicrobial treatment with multiple antimicrobials, including levofloxacin and linezolid.

CONCLUSIONS

There is little evidence to guide practitioners in the diagnosis and treatment of PJI caused by rare, rapidly growing mycobacteria (RGM) such as M. fortuitum. This case demonstrates a successful strategy for the treatment of RGM PJI.

Mid-term follow-up after all-size acetabular revision and proposal for a stability classification system

BACKGROUND

There is a trend for using jumbo cups/oblong devices for acetabular reconstruction as alternative to biological solutions. We report about a spectrum of reconstruction methods and their mid-term results.

METHODS

Inclusion of 214 consecutive patients undergoing total hip arthroplasty revision surgery. Patients were examined using the Harris Hip Score (HHS). Based on the intraoperative acetabular defect situation, cases were classified into 1 of 5 possible categories of a stability classification for acetabular replacement (SCAR).

RESULTS

Mean HHS improved from 42 preoperatively (range 12-62) to 77 (range 54-90; p < 0.05) 6 months after operation. There were significant differences of the pre-and postoperative HHS between SCAR subgroups (p < 0.05). Inter-observer reliability of the SCAR was high (kappa 0.94 (95% CI, 0.90-0.98)). Re-revision was performed in 15 cases (7%).

CONCLUSION

The SCAR classification is a practicable tool for intraoperative decision-making as it provides standardised treatment recommendations.

Managing persistent wound leakage after total knee and hip arthroplasty. Results of a nationwide survey among Dutch orthopaedic surgeons

Background: Persistent wound leakage after joint arthroplasty is a scantily investigated topic, despite the claimed relation with a higher risk of periprosthetic joint infection. This results in a lack of evidence-based clinical guidelines for the diagnosis and treatment of persistent wound leakage after joint arthroplasty. Without such guideline, clinical practice in orthopaedic hospitals varies widely. In preparation of a nationwide multicenter randomized controlled trial on the optimal treatment of persistent wound leakage, we evaluated current Dutch orthopaedic care for persistent wound leakage after joint arthroplasty. Methods: We conducted a questionnaire-based online survey among all 700 members of the Netherlands Orthopaedic Association, consisting of 23 questions on the definition, classification, diagnosis and treatment of persistent wound leakage after joint arthroplasty. Results: The questionnaire was completed by 127 respondents, representing 68% of the Dutch hospitals that perform orthopaedic surgery. The results showed wide variation in the classification, definition, diagnosis and treatment of persistent wound leakage among Dutch orthopaedic surgeons. 56.7% of the respondents used a protocol for diagnosis and treatment of persistent wound leakage, but only 26.8% utilized the protocol in every patient. Most respondents (59.1%) reported a maximum period of persistent wound leakage before starting non-surgical treatment of 3 to 7 days after index surgery and 44.1% of respondents reported a maximum period of wound leakage of 10 days before converting to surgical treatment. Conclusions: The wide variety in clinical practice underscores the importance of developing an evidence-based clinical guideline for the diagnosis and treatment of persistent wound leakage after joint arthroplasty. To this end, a nationwide multicenter randomized controlled trial will be conducted in the Netherlands, which may provide evidence on this important and poorly understood topic.

Evaluation of bone viability in patients after girdlestone arthroplasty: comparison of bone SPECT/CT and MRI

PURPOSE

To test the diagnostic performance of bone SPECT/CT and MRI for the evaluation of bone viability in patients after girdlestone-arthroplasty with histopathology used as gold standard.

MATERIALS AND METHODS

In this cross-sectional study, patients after girdlestone-arthroplasty were imaged with single-photon-emission-computed-tomography/computed-tomography (SPECT/CT) bone-scans using 99mTc-DPD. Additionally, 1.5 T MRI was performed with turbo-inversion-recovery-magnitude (TIRM), contrast-enhanced T1-fat sat (FS) and T1-mapping. All imaging was performed within 24 h prior to revision total-hip-arthroplasty in patients with a girdlestone-arthroplasty. In each patient, four standardized bone-tissue-biopsies (14 patients) were taken intraoperatively at the remaining acetabulum superior/inferior and trochanter major/minor. Histopathological evaluation of bone samples regarding bone viability was used as gold standard.

RESULTS

A total of 56 bone-segments were analysed and classified as vital (n = 39) or nonvital (n = 17) by histopathology. Mineral/late-phase SPECT/CT showed a high sensitivity (90%) and specificity (94%) to distinguish viable and nonviable bone tissue. TIRM (sensitivity 87%, specificity 88%) and contrast-enhanced T1-FS (sensitivity 90%, specificity 88%) also achieved a high sensitivity and specificity. T1-mapping achieved the lowest values (sensitivity 82%, specificity 82%). False positive results in SPECT/CT and MRI resulted from small bone fragments close to metal artefacts.

CONCLUSIONS

Both bone SPECT/CT and MRI allow a reliable differentiation between viable and nonviable bone tissue in patients after girdlestone arthroplasty. The findings of this study could also be relevant for the evaluation of bone viability in the context of avascular bone necrosis.

Sonication of explanted prosthesis combined with incubation in BD bactec bottles for pathogen-based diagnosis of prosthetic joint infection

Prosthetic joint infection (PJI) is a rare but refractory complication of arthroplasty. Accurate identification of pathogens is a key step for successful treatment of PJI, which remains a challenge for clinicians and laboratory workers. We designed a combined culture method with sonication of implants and incubation in a BD Bactec system to improve the effectiveness of pathogen diagnosis in PJI. The aims of this study were to investigate the diagnostic accuracy of sonicate fluid cultures in the BD Bactec system and to compare the results with those of synovial fluid cultures in the BD Bactec system. The prosthetic components removed were sonicated in Ringer's solution, and then sonicate fluid was incubated in Bactec bottles for 5 days. Synovial fluid was incubated in Bactec bottles for 5 days as a control. Synovial fluid cultures with Bactec bottles and sonicate fluid cultures with Bactec bottles showed sensitivities of 64% and 88%, respectively (P = 0.009), with specificities of 98% and 87% (P = 0.032), respectively. Sonicate fluid cultures with Bactec bottles were more sensitive than synovial fluid cultures with Bactec bottles regardless of whether antimicrobial agents were used within 14 days before surgery (81% versus 52%; P = 0.031) or not (93% versus 72%; P = 0.031). Sonication of explanted prostheses followed by incubation of the resulting sonicate fluid in Bactec bottles detected many more pathogens than did synovial fluid cultures with Bactec bottles. This method is also effective in cases with antibiotic treatment before surgery.

Identification of periprosthetic joint infection after total hip arthroplasty

Although total hip arthroplasty (THA) is accepted as one of the most successful surgical procedures in orthopaedic surgery, periprosthetic joint infection after THA continues to be one of the most devastating complications. However, accurate preoperative identification of periprosthetic joint infection in patients presenting with joint pain or radiographic periprosthetic lucencies is often difficult, even after a comprehensive work-up. The purpose of this article is to review the diagnostic options available to improve the management and results of this potentially catastrophic complication.

Readmissions after diagnosis of surgical site infection following knee and hip arthroplasty

CONTEXT

Surgical site infection (SSI) after total hip and knee arthroplasty is a common postoperative complication. We sought to determine readmission rates and costs for total hip and knee arthroplasty complicated by SSI.

DESIGN

The Thomson Reuters MarketScan database was searched for patients who underwent knee or hip arthroplasty in 2007. From these data, patients who received a diagnosis of SSI and were readmitted after diagnosis were identified.

SETTING

A population of 31 to 45 million individuals receiving insurance coverage. Patients who underwent knee or hip arthroplasty who experienced a hospitalization for SSI in the year after surgery were analyzed.

OUTCOME MEASURES

Total readmission rates and costs per readmission at 30, 60, and 90 days and 1 year after diagnosis of SSI.

RESULTS

Of the 76,289 case patients with hip or knee replacement in 2007, 1,026 (1.3%) had a hospitalization for SSI within the year after surgery. Among these patients, 310 (30.2%) were subsequently rehospitalized in the year after initial hospitalization specifically due to SSI-related issues. These rehospitalizations were associated with a mean hospital stay of [Formula: see text] days and a median cost of $20,001 (interquartile range [IQR], $14,057-$30,551). A total of 517 subjects had a subsequent "all-cause" hospitalization during the year after SSI. These rehospitalizations were associated with a mean hospital stay of [Formula: see text] days and a median cost of $19,870 (IQR, $13,913-$29,728).

CONCLUSIONS

Readmissions during the year after SSI diagnosis accounted for 1,072 hospital admissions and cost over $25.5 million. These readmissions are costly and might be a future target for decreased reimbursement.

[Etiology and classification of septic coxitis]

Septic coxitis is a rare disesase which can be caused by a variety of pathogens. Primary and secondary coxitis can be differentiated depending on the etiology. In the initial stages the diagnosis is difficult but a delay in making the correct diagnosis or delayed therapy can result in fatal consequences for the patient, therefore, therapy should be started even in cases of suspected septic coxitis. Septic coxitis is classified into four stages depending on the arthroscopic findings. The best results are usually achieved by a combination of arthroscopic lavage and antibiotic therapy.