The Unusual Cause of Prosthetic Joint Infection: Outcomes of Nontuberculous Mycobacteria Treatment Following Primary Total Knee Arthroplasty.

Background: Nontuberculous mycobacterium (NTM) is a rare cause of prosthetic joint infection (PJI) following primary total knee arthroplasty (TKA). NTM causes a variety of infections, mainly divided into pulmonary and extrapulmonary infections. In Pakistan, there was a 7.7-fold increase in NTM infections from 21 cases in 2012 to 163 cases in 2018. An earlier study evaluating the distribution of NTM species across Pakistan suggested geographical variation across different regions, every area having its own distribution spectrum. There are no data available especially in developing countries such as Pakistan regarding PJI due to NTM following primary TKA. The purpose of our study was to determine treatment outcomes of two-stage revision surgery following NTM infection. Methods: This is a retrospective study. Patients who underwent TKA between June 2008 and December 2018 were included in the study. NTM was defined as the presence of traditional criteria for diagnosing PJI plus growth of NTM cultured from a joint aspirate or deep periprosthetic tissue specimen using Löwenstein-Jensen medium and Mycobacteria Growth Indicator Tube medium. All patients were female with a mean age of 62.8 ± 7.9 years. The mean body mass index was 25.6 ± 2.8 kg/m2. Treatment outcomes were categorized into favorable and unfavorable. Results: We found rapid-growing mycobacterium in 6 patients whereas slow-growing mycobacterium was found in 2 patients only. Generally, clarithromycin was the standard antibiotic used in all cases of NTM infections. All patients underwent revision surgery. Conclusions: Meticulous surgical debridement and prolonged antibiotic treatment course were the only hope of cure to combat the unusual cause of PJI following primary TKA.

Mid-term results and survival rates following a single-design rotating hinge knee arthroplasty in non-tumor conditions in a Pakistani population.

BACKGROUND: Information regarding the use of hinged implants in non-oncological conditions is limited in our region due to a lack of adequate data collection and follow-up. The purpose of this study is to evaluate mid-term results and risk factors affecting the survivorship of third-generation rotating hinge knee (RHK) patients in non-oncological conditions. METHODS: We retrospectively reviewed 41 single, third-generation, rotating hinge prostheses in three complex primary knee procedures and 38 revision knee surgeries in between 2007 to 2014. Implant survival was assessed using the Kaplan-Meier method. Factors influencing implant survival were identified using the log-rank test. During the study period, clinical results along with complications were assessed. Clinical outcomes were assessed by using the Knee Society Score (KSS). RESULTS: RHK arthroplasty was used in 41 patients. Out of 41 patients, a RHK was used in three patients with a complex primary deformed knee whereas in 38 patients, a RHK was used in revision arthroplasty surgery. The cumulative implant survival rate with re-revision due to any cause was found to be 87.8% (95% CI 69.2-90.1) at 5-7 years. Prosthetic joint infection, peri-prosthetic fracture and extensor mechanism complications were the commonest mode of failure. The P value was found to be significant when comparing KSS pre-operatively and post-operatively. CONCLUSION: The cumulative implant survival rate was found to be 87.8%. Prosthetic joint infection was the commonest mode of failure in patients who underwent third-generation RHK surgery for variable indications. Being a patient with a high Charlson comorbidity index is the main risk factor associated with failure of the rotating hinge implant.

Impact of Tibial Tubercle Osteotomy on Final Outcome in Revision Total Knee Arthroplasty: Our Experience and Technique in Pakistan.

BACKGROUD: Due to extensive fibrosis during revision surgery, adequate exposure is essential and it can be achieved with several extensile approach options, such as tibial tubercle osteotomy. Information regarding surgical exposure during revision arthroplasty is limited in developing countries, such as Pakistan, due to the lack of adequate data collection and follow-up. Therefore, the purpose of this study was to evaluate the impact of tibial tubercle osteotomy on final outcome of revision total knee arthroplasty (TKA). METHODS: A total of 231 revision TKAs were performed between January 2008 and December 2017. Twenty-nine patients underwent tibial tubercle osteotomy for adequate exposure during revision surgery. Of these, 27 patients with complete follow-up were included in our study. Factors examined include age at the time of revision surgery, gender, comorbidities, arthroplasty site (right or left), body mass index (BMI), and primary indications for the tibial tubercle osteotomy during revision TKA. Functional outcome was measured by using Knee Society score (KSS) at 3 months and the final follow-up. All statistical analysis was done using SPSS version 20.0 with a p-value < 0.05 considered significant. RESULTS: Out of 27 patients, 6 patients (22.2%) were men and 21 patients (77.7%) were women. Right knee revision arthroplasty was performed in 15 patients (55.5%), left knee revision arthroplasty was performed in 12 patients (44.4%), and bilateral revision surgery was performed in only 1 patient (3.7%). The mean BMI was 29.2 kg/m2. We used a constrained condylar knee in 20 patients (74%), a rotating hinge knee in 5 patients (18.5%), and mobile bearing tray plus metaphyseal sleeves in 2 patients (7.4%). The KSS was 52.21 ± 4.05 preoperatively, and 79.42 ± 2.2 and 80.12 ± 1.33 at 3 months and 12 months, respectively. Radiological union was achieved in all patients at 3 months. Of 27 patients, only 1 patient (3.7%) had proximal migration of the osteotomy site at 6 months: the patient was asymptomatic and union was also achieved and, therefore, no surgical intervention was performed. CONCLUSIONS: Tibial tubercle osteotomy during revision TKA can be a safe and reliable technique with superior outcomes and minimal complication rates.

Ball tipped guide wire for broken nail removal: a case report.

A broken intramedullary nail is a well-known complication of non-union of femur shaft fractures. Numerous surgical techniques have been presented before in patients with non-union of long bone fractures. We report the surgical technique used to perform removal of the broken distal segment of a nail in a patient who achieved uneventful union after intramedullary nailing of closed femur shaft fracture. A ball-tipped guidewire was inserted through the broken segment of the femur nail. A pre-bend plain wire was then inserted. With the help of a vise-grip, both wires were twisted in order to make a secure handle between guidewires and a broken implant. With the help of a mallet upward-directed blows were applied to extract a broken segment of the nail. We found ball-tipped guidewire technique a useful and effective technique in removing the broken distal portion of the nail.

Bilateral severe heterotopic ossification following primary total knee arthroplasty: a case report in Pakistan.

The incidence of unilateral minor heterotopic ossification after primary total knee arthroplasty is still unknown, but bilateral severe heterotopic ossification is rare and has not been reported before. Presented in this report is a 60-year-old female patient who developed bilateral knee pain and stiffness 2 weeks after primary total knee arthroplasty. Her weight was 70 kg and body mass index was 32.2. Preoperatively, she had bilateral varus deformity of both knees. X-rays taken 3 months after surgery revealed bilateral severe heterotopic ossification. The patient had been on non-operative treatment (including anti-inflammatory drugs and physiotherapy). There was a marked improvement 6 months after surgery. This case report showed the non-operative treatment may produce acceptable results for patients with severe bilateral heterotopic ossification after primary total knee arthroplasty, and exerted no influence on the final clinical outcome.

Economic Burden of Periprosthetic Joint Infection Following Primary Total Knee Replacement in a Developing Country.

BACKGROUND: Periprosthetic joint infection is one of the devastating complications after primary total knee arthroplasty, which increases the financial burden on patients and affects their quality of life as well. The financial burden of periprosthetic joint infection after joint replacement in developed countries is well known. There is a need to evaluate the economic burden in developing countries such as Pakistan. METHODS: This is a single-center, retrospective, case-control study conducted at the Department of Orthopedic Surgery, Liaquat National Hospital Karachi. Cases of primary total knee arthroplasty performed during this study were divided into 2 groups: uneventful primary total knee arthroplasty and periprosthetic joint infection treated with 2-stage revision. To calculate the final cost, we divided the total hospital cost into the hospital stay cost and operating room cost. RESULTS: During study period, 32 patients were diagnosed with periprosthetic joint infection. The total cost of revision surgery for periprosthetic joint infection considering 2 hospitalizations was 1,780,222 ± 313,686 Pakistani rupee (PKR). The total cost of uneventful arthroplasty was 390,172 ± 51,460 PKR. We observed significant difference with respect to economic details between the 2 groups. CONCLUSIONS: Management of periprosthetic joint infection was 4.5 times more expensive than uneventful primary total knee arthroplasty. Measures should be undertaken to reduce the prevalence of periprosthetic joint infection, thereby reducing patients' economic burden.