The risks of pulmonary embolism and upper gastrointestinal bleeding beyond 35days after total hip replacement for coxarthrosis among middle-aged patients: A cross-over cohort

A finite element study on the interactive effect between the damage of the cup-bone interface and the bone strain of hip implants under various fixation conditions

Interfacial damage has a high impact on the loosening of the acetabular cup. However, monitoring this damage induced by the variations in loading conditions, such as the angle, amplitude, and frequency in vivo, is challenging. In this study, we evaluated the risk of loosening of the acetabular cup due to interfacial damages induced by the deviation in loading conditions and amplitudes. A three-dimensional model of the acetabular cup component was developed, and the interfacial crack growth between the cup and the bone was modeled using a fracture mechanics approach, which simulated the extent of interfacial damage and associated cup displacement. The interfacial delamination mechanism changed with the increasing inclination angle, wherein a fixation angle of 60° exhibited the largest area of contact loss. The compressive strain of embedding the simulated bone at the remaining bonding area accumulated as the lost contact area widened. Such interfacial damages, namely, the growth of the lost contact area and accumulated compressive strain in the simulated bone, promoted both embedding and rotational displacement of the acetabular cup. In the worst case of a fixation angle of 60°, the total displacement of the acetabular cup exceeded the limit of the modified safe zone, suggesting a quantitative risk of dislocation of the acetabular cup induced by the accumulated interfacial damage. Furthermore, nonlinear regression analyses between the degree of displacement of the acetabular cup and the extent of the two types of interfacial damage demonstrated that the interactive effect of the fixation angle with the loading amplitude showed a significant effect on increasing cup displacement. These findings suggest that proper control of the fixation angle during operation is useful in preventing the loosening of the hip joint.

Does hip or knee joint replacement decrease chances to complete an ultra-trail race? Study in participants at the Ultra-Trail du Mont Blanc®

INTRODUCTION

The number of patients with hip or knee joint replacements is increasing. Some of these patients want to practice sport, including in high-impact sports such as ultra-trails. Is the proportion of drop-out higher among runners after a hip or knee replacement? What are the symptoms of these patients?

HYPOTHESIS

Hip or knee joint replacements are associated with a higher drop-out rate during an ultra-trail.

MATERIAL AND METHODS

We conducted a monocentric retrospective epidemiological study. A questionnaire translated into French, English and Spanish were sent to all runners registered for one or more of the 5 races of the 2015 to 2017 Ultra-Trail du Mont-Blanc® (UTMB®) editions. There were no exclusion criteria. The drop-out rate of patients who responded to the questionnaire was calculated among patients with and without hip or knee joint replacement. Specific symptoms related to these joint replacements were identified before, during and after the race.

RESULTS

Out of the 24,855 participants having run at least one of the 3 editions, 2,469 responded. Some of them ran several races: these 2469 runners were on 3171 start lines and 2548 finish lines (drop-out rate of 19.6%). Among these 2469 runners, 18 had hip and/or knee replacement and were on 27 start lines and 17 finish lines (drop-out rate of 37%). The race was finished by 3 of the 6 runners with a total hip arthroplasty (THA), all of the 8 runners with a hip resurfacing arthroplasty (HRA) and 3 of the 4 runners with a total knee arthroplasty (TKA). Among runners with THA, pubalgia or groin pain was described by one of them before the race, 3 during the race and 2 after the race. Among runners with HRA, pygalgia or groin pain was described by 2 of them during the race. As for the TKA, there was no specific symptom. No answering runner had a unicompartmental knee prosthesis.

DISCUSSION

Running ultra-trail is possible after a hip or knee joint replacement. All of the 8 runners with HRA finished the race. We may remain cautious about the long-term survival of prostheses.

LEVEL OF PROOF

IV; monocentric retrospective epidemiological study.

Gastrointestinal Complications Warranting Invasive Interventions Following Total Joint Arthroplasty

BACKGROUND

Gastrointestinal (GI) complications following total joint arthroplasty (TJA) are uncommon but can be associated with substantial morbidity and mortality. The current literature on GI complications that warrant invasive procedures after TJA is lacking. This study reviews the incidence and outcomes of GI complications after TJA that went on to require invasive procedures.

METHODS

All TJA patients at our institution between January 2012 and May 2018 who had GI complications requiring an invasive procedure within 30 days of TJA were identified and retrospectively chart reviewed. Descriptive statistics were used to evaluate these patients.

RESULTS

Of 19,090 TJAs in a 6-year period, 34 patients (0.18%) required invasive procedures for GI complications within 30 days of the index surgery. Twenty-two (64%) of the required procedures were endoscopy for suspected GI bleeding. Within this cohort, aspirin was the most common thromboprophylaxis used (63.6% of patients) and smoking was more prevalent (9.1% current smokers) (P = .28). Of the remaining 12 GI procedures required, 75% were exploratory laparotomies, 44.4% of which were performed for obstruction. Three (33.3%) of the exploratory laparotomy patients died during the study period.

CONCLUSION

GI complications necessitating surgical intervention after TJA are rare. Suspected GI bleeding is the most common indication for intervention and is typically managed endoscopically. Other complications, such as GI obstruction, often require more extensive intervention and open procedures. Though rare, GI complications following TJA can lead to detrimental outcomes, significant patient morbidity, and occasionally mortality; therefore, a heightened awareness of these complications is warranted.