Calcium sulphate mixed with antibiotics does not decrease efficacy against Cutibacterium acnes (formerly Propionibacterium acnes), in vitro study.

BACKGROUND: This study explored the in vitro efficacy of antibiotics mixed with calcium sulfate (ACS) against Cutibacterium acnes (C. acnes). METHODS: C. acnes isolates from orthopaedic infection sites were tested for antimicrobial susceptibility with ACS. Minimal inhibitory concentrations (MIC) were determined with a gradient diffusion method (Etest® strips). RESULTS: When tested with Etest®, all 22 isolates were susceptible to penicillin, ceftriaxone, vancomycin, and two were resistant to clindamycin (MICs of 4 and 8 mg/L). Penicillin and rifampin had the largest inhibition zone diameters. CONCLUSIONS: Antibiotics retained activity against C. acnes when mixed with calcium sulfate.

Factors affecting outcome of partial radial head fractures: A Retrospective Cohort Study.

BACKGROUND: The purpose of this study is to evaluate which factors will affect range of motion (ROM) and function in partial radial head fractures. The hypothesis is that conservative treatment yields better outcomes. MATERIALS AND METHODS: This retrospective comparative cohort study included 43 adult volunteers with partial radial head fracture, a minimum 1-year follow up, separated into a surgical and non-surgical group. Risk factors were: associated injury, heterotopic ossification, worker's compensation, and proximal radio ulnar joint (PRUJ) implication. Outcomes included radiographic ROM measurement, demographic data, and quality of life questionnaires (PREE, Q-DASH, MEPS). RESULTS: Mean follow up was 3.5 years (1-7 years). Thirty patients (70%) had associated injuries with decreased elbow extension (-11°, p=0.004) and total ROM (-14°, p=0.002) compared to the other group. Heterotopic ossification was associated with decreased elbow flexion (-9.00°, p=0.001) and fractures involved the PRUJ in 88% of patients. Only worker's compensation was associated with worse scores. There was no difference in terms of function and outcome between patients treated non-surgically or surgically. DISCUSSION: We found that associated injuries, worker's compensation and the presence of heterotopic ossification were the only factors correlated with a worse prognosis in this cohort of patients. Given these results, the authors reiterate the importance of being vigilant to associated injuries. LEVEL OF EVIDENCE: IV, Retrospective study.

Involvement of the proximal radial ulnar joint in partial radial head fractures: a novel three-dimensional computed tomography scan evaluation method.

BACKGROUND: Partial radial head fractures (PRHF) can involve the proximal radioulnar joint (PRUJ) or be restricted to the 'safe zone' (SZ) during forearm rotation. The objective of the present study was to develop an assessment method for PRUJ involvement in radial head fractures using axial computed tomography (CT) scans. METHODS: The area of the radial head in contact with the PRUJ zone was identified, and defined on 18 cadaveric elbows CT scans; the quantitative relationship between PRUJ zone and radial tuberosity was established. Then, four evaluators validated it on PRHF CT scan axial views, classifying the fractures as involving the PRUJ or not. RESULTS: Using the radial tuberosity as the 0° of a 360° circle, the SZ was within 108° to 212° clockwise for a right elbow and counter clockwise for the left elbow. Fifty-five consecutive (30 men, 25 women, mean age of 49 years) partial radial head fracture CT scans were classified: four in the SZ only, three in the PRUJ zone and 48 in both the PRUJ and SZ. The kappa for the inter- and intra-observer agreement was 0.517 and 0.881, respectively. CONCLUSIONS: Ninety-three percent of partial radial head fractures will involve the PRUJ and the geometric model developed allows their classification, potentially helping surgeons decide on optimal treatment. LEVEL OF EVIDENCE: Retrospective basic science study. Level III: anatomic study, imaging.