Diagnostic performances and therapeutic impact of the Unyvero Implant and Tissue Infection multiplex PCR in periprosthetic joint infections.

Aim: We evaluated the diagnostic performances of Unyvero Implant and Tissue Infection multiplex PCR (mPCR) (Curetis) and the clinical impact of this PCR on therapeutic decisions. Materials & methods: A mPCR was performed on 33 joint fluids in addition to standard culture. A group of experts analyzed a posteriori the impact of the mPCR in the patient management. Results: The rate of concordance with culture was 74% (20/27). The sensitivity of the PCR was 59% and the specificity 90%. Clinicians would have started an appropriate treatment sooner for six patients (from 2 to 22 days earlier). Conclusion: The PCR would improve the management of 22% of the patients. For other patients, mPCR results have to be completed with the culture.

Clinical and radiological outcomes of antegrade posterior column screw fixation of the acetabulum.

INTRODUCTION: Antegrade posterior column screw fixation (APCS) provides stable fixation while reducing the complications related to dual acetabular approaches. The objective of this study was to present the radiological and clinical outcomes of fixation of the posterior column of the acetabulum through a single anterior approach. HYPOTHESIS: APCS will produce better clinical and radiological outcomes relative to not placing any screws in the posterior column. PATIENTS AND METHODS: This was a retrospective single-center study of 69 patients operated through a single anterior approach for a both-column fracture of the acetabulum between 2014 and 2018. Patients were divided into two groups (APCS+, n=24 and APCS-, n=45) depending on whether the posterior column was fixed with an antegrade lag screw or not. The radiological outcomes were defined by the quality of the reduction according to Matta. The clinical outcomes were evaluated using the Harris Hip score and Merle Postel D'Aubigné (MDP) score at the final assessment. A sequential hierarchical analysis was done with a Chi2 test for the radiological criterion and Student's t test for the clinical outcomes. RESULTS: In the APCS+ group, the reduction was anatomical in 71% (17/24) of patients, imperfect in 12% (3/24) and poor in 17% (4/24). In the APCS- group, the reduction was anatomical in 33% (15/45) of patients, imperfect in 31% (14/45) and poor in 35% (16/45). This difference between groups was statistically significant (p=.012). The differences between groups in the Harris (p=.201) and MDP (p>.05) scores were not significant. Mean irradiation in the APCS+ group was significantly higher (114.8 cGy.cm-2) relative to the APCS- group (39.8 cGy.cm-2) (p<.001). None of the patients in the APCS+ group underwent a subsequent total hip arthroplasty, while 8 patients from the APCS- group did (p=.031). The differences in the postoperative complications were not statistically significant. DISCUSSION: APCS yields satisfactory radiological and clinical outcomes without increasing the complication rate; this must be balanced out against the additional irradiation. LEVEL OF EVIDENCE: III.

Complications and outcomes in 69 consecutive patients with floating hip.

BACKGROUND: Floating hip is a rare and potentially serious injury. The objective of this study was to evaluate our management strategy for patients with floating hip. HYPOTHESIS: A standardized strategy with specialised multidisciplinary management is associated with a low mortality rate. METHODS: Consecutive patients who had surgery to treat floating hip between January 2010 and December 2019 were included in this single-centre retrospective study. Epidemiological, clinical, and radiological data were collected and analysed. Patients were managed according to a standardised strategy adapted to the haemodynamic status and type of floating hip (type A, femoral and pelvic ring fractures; type B, femoral and acetabular fractures; and type C, femoral, acetabular, and pelvic ring fractures). The clinical outcome at last follow-up was determined by a telephone interview, based on the Majeed and Oxford scores, sports resumption, and work resumption. To assess the radiological outcomes, we applied Matta's criteria for the acetabulum and Tornetta's criteria for the pelvic ring. RESULTS: We included 69 patients with a mean age of 38.5 years. Among them, 39 (57%) had haemodynamic instability requiring embolisation (n=15, 22%) or multiple blood transfusions (n=24, 35%). Type A injuries predominated (n=57, 83%). The need for multiple blood transfusions was significantly associated with type C floating hip, underlining the risk of heavy bleeding with this injury. Two (3%) patients died. When management was complete, the reduction was anatomical or satisfactory for 76% (13/17) of the acetabula according to Matta's criteria (maximum residual displacement <3mm) and for 85% (56/66) of the pelvic rings according to Tornetta's criteria (maximum residual displacement <10mm). One or more complications occurred in 45 (65%) patients. After a mean follow-up of 5 years, the mean Oxford Hip Score in patients with acetabular fractures was 35.5 and the mean Majeed score in patients with pelvic ring fractures was 71.5. Only 30% of patients were able to resume physical activities at the former level and to return to their former professional activities. CONCLUSION: Type C floating hip, which combines fractures of the pelvic ring and acetabulum, carries a high risk of bleeding. Special attention should be directed to the reduction of pelvic ring fractures, to avoid malunion. Acetabular fractures that are complex in the Letournel classification carry a risk of imperfect reduction. The results of this study confirm the severity of these rare injuries and the need for specialised multidisciplinary management according to a standardised strategy that is appropriate for the haemodynamic status and type of floating hip (A, B, or C). LEVEL OF EVIDENCE: IV; retrospective study.

Role of 3D intraoperative imaging in orthopedic and trauma surgery.

Intraoperative three-dimensional (3D) imaging is now feasible because of recent technological advances such as 3D cone-beam CT (CBCT) and flat-panel X-ray detectors (FPDs). These technologies reduce the radiation dose to the patient and surgical team. The aim of this study is to review the advantages of 3D intraoperative imaging in orthopedic and trauma surgery by answering the following 5 questions: What are its technical principles? CBCT with a FPD produces non-distorted digital images and frees up the surgical field. The high quality of these 3D intraoperative images allows them to be integrated into surgical navigation systems. Human-robot comanipulation will likely follow soon after. Conventional multislice CT technology has also improved to the point where it can be used in the operating room. What can we expect from 3D intraoperative imaging and which applications have been validated clinically? We reviewed the literature on this topic for the past 10 years. The expected benefits were determined during the implantation of pedicular screws: more accurate implantation, fewer surgical revisions and time savings. There are few studies in trauma or arthroplasty cases, as robotic comanipulation is a more recent development. What is the tolerance for irradiation to the patient and surgical team? The health drawbacks are the harmful radiation-induced effects. The deterministic effects that we will develop are correlated to the absorbed dose in Gray units (Gy). The stochastic and carcinogenic effects are related to the effective dose in milliSievert (mSv) of linear evolution without threshold. The International Commission on Radiological Protection (ICRP) states that irradiation for medical purposes with risk of detriment is acceptable if it is justified by an optimization attempt. The radioprotection limits must be known but do not constitute opposable restrictions. The superiority of intraoperative 3D imaging over fluoroscopy has been demonstrated for spine surgery and sacroiliac screw fixation. How does the environment need to be adapted? The volume, access, wall protection and floor strength of the operating room must take into account the features of each machine. The instrumentation implants and need for specialized staff result in additional costs. Not every system can track movements during the CBCT acquisition thus transient suspension of assisted ventilation may be required. Is it financially viable? This needs to be calculated based on the expected clinical benefits, which mainly correspond to the elimination of expenses tied to surgical revisions. Our society's search for safety has driven the investments in this technology. LEVEL OF EVIDENCE: V, Expert opinion.