Epidemiology of hip & knee replacement across Pakistan: Multicenter cross-sectional study.

Objective: To know about the predictive prevalence of hip and knee arthroplasty across Pakistan. Methods: It is retrospective cross-sectional study with data collection from Pakistan National Joint Registry (PNJR) of number of hip and knee arthroplasty cases in seven years (2014-2021). Fourteen high volume centers across Pakistan who consented for data publication were included. Stata version 16 was used for data analysis. Mean & standard deviation was reported for quantitative variable & frequency and proportion were reported for qualitative variables. Results: Our results showed a total of 9572 people had total knee replacement in last seven years from 2014-2021 with the rate of 9.57/100,000 population. Mean age of the patient was 61.7±8.95 with 69.5% patients being female and 30.5% being male. Our results showed a total of 2265 people had total hip replacement in last seven years from 2014-2021with the rate of 2.26/100,000 population. Mean age of the patient was 50.7±15.4 with 62% patients being male and 38% being female. Conclusion: This is the first epidemiological study in Pakistan on the rates of hip and knee arthroplasty cases in Pakistan based on registry data, showing that more knee arthroplasty cases are being performed as compared to hip arthroplasty.

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.