The reliability of posterior malleolar ankle fracture assessment: a unique perspective.

AIM: This study aims to elucidate the pathology of PMFs in the South African population, establish correlations between fracture patterns and international classification guidelines and evaluate the interobserver reliability of current classifications. METHODS: A retrospective review was conducted in a multicentre analysis over a one-year period from January 2019 to December 2019 at our institution. Computer tomography scans for foot and ankle injuries were reviewed, and posterior malleolus fractures were included. Pathoanatomical data was collected and analysed according to known classification systems and subsequent treatment modalities evaluated. A panel of observers individually reviewed radiographic data to determine interobserver reliability. RESULTS: A total of 71 patients were included with a mean age of 41 ± 13.4 years (range 18-78) and a female predominant population (69%). A greater proportion of injuries were high energy (23.9%), with significant fragment comminution (53.5%), and half (52.1%) of all injuries were subluxated/dislocated at presentation. A total of 93% of injuries were managed operatively, despite theatre access limitations resulting in significant delays to fixation (19.1 days). Despite good pathoanatomical agreement with most international classifications, interobserver reliability was poor (Krippendorff α-coefficient < 0.667). Inconsistent treatment patterns in operative and non-operative strategies are reported. CONCLUSION: A unique patient population of younger, female individuals incurred posterior malleolar fractures due to higher energy mechanisms of injury. Whilst injury patterns were mostly comparable, significant interobserver variability was noted. Resource limitations, diagnostic challenges, poorly defined and inconsistent treatment strategies, inevitably impact outcomes within the South African population. LEVEL OF EVIDENCE: Level III.

Artificial fish nurseries can restore certain nursery characteristics in marine urban habitats.

Port areas are subjected to multiple anthropic pressures that directly impact residing marine communities and deprive them of most of their essential ecological functions. Several global projects aim to rehabilitate certain ecosystem functions in port areas, such as a fish nursery function, by installing artificial fish nurseries (AFN). In theory, AFNs increase fish biodiversity and juvenile fish abundance in port areas, but studies on this subject remain scarce. Thus, the present study aimed to examine whether the use of such AFNs could restore part of the nursery function of natural habitats by increasing fish and juvenile abundance, and by decreasing predation intensity compared to bare docks. Two years of monitoring on AFNs showed they hosted 2.1 times more fish than on control docks and up to 2.4 more fish juveniles. Fish community structures were influenced by both treatment (AFN and Control) and year of monitoring. In general, AFNs hosted a greater taxonomic diversity of fish than controls. The predation intensity around these structures was significantly lower in the AFNs than in controls. Part of the definition of a fish nursery was thus verified, indicating that AFNs might be an effective restoration tool. However, we also noted that total fish abundance and Young of the Year (YOY) abundance decreased in controls, possibly due to a concentration effect. Further detailed monitoring is necessary to distinguish between these effects.

The elephant in the room: Introduced species also profit from refuge creation by artificial fish habitats.

Increasingly, ecological rehabilitation is envisioned to mitigate and revert impacts of ocean sprawl on coastal marine biodiversity. While in the past studies have demonstrated the positive effects of artificial fish habitats in port areas on fish abundance and diversity, benthic colonization of these structures has not yet been taken into consideration. This could be problematic as they may provide suitable habitat for Non-Indigenous Species (NIS) and hence facilitate their spreading. The present study aimed to examine communities developing on artificial fish habitats and to observe if the number of NIS was higher than in surrounding equivalent habitats. The structures were colonized by communities that were significantly different compared to those surrounding the control habitat, and they were home to a greater number of NIS. As NIS can cause severe ecological and economical damages, our results imply that in conjunction with the ecosystem services provided by artificial fish habitats, an ecosystem disservice in the form of facilitated NIS colonization may be present. These effects have not been shown before and need to be considered to effectively decide in which situations artificial structures may be used for fish rehabilitation.

Temporary circular external fixation for spanning the traumatised ankle joint: A cohort comparison study.

BACKGROUND: Temporary spanning fixation aims to provide bony stability whilst allowing access and resuscitation of the traumatised soft-tissue envelope. Conventional monolateral fixators are prone to half-pin morbidity in feet, variation in construct stability and limited weight-bearing potential. This study compares traditional delta-frame monolateral external fixators to ankle spanning circular fixators. METHODS: Two cohorts were matched for demographics and fracture patterns. The quality of initial reduction and the maintenance of reduction until definitive surgery was assessed by two authors and categorised into four domains. Secondary measures included fixator costs, time to definitive surgery and complications. RESULTS: Fifty-five delta-frames and 51 circular fixators were statistically matched for demographics and fracture pattern. "Excellent" and "Good" initial reduction was achieved in 50 (91%) delta-frames and 51 (100%) circular fixators (p = 0.027). Deterioration of initial reduction quality was seen in 12 (22%) delta-frames and two (4%) circular fixators (p < 0.001). Post-fixator dislocation occurred in five (9%) delta-frames and one (2%) circular fixator (p = 0.147). Median duration in spanned fixation was 11 days in both groups (p = 0.114). Three (5%) delta-frames and 13 (25%) circular fixators were used as definitive fixation. The mean implant cost was 4,307 USD for delta-frames and 3747 USD for circular fixators. CONCLUSION: Temporary spanning circular fixation offers superior intra-operative reduction and maintenance of reduction and provides more opportunity to be used as definitive fixation. Circular fixation implants also proved to be less expensive and protected against further scheduled or unscheduled returns to theatre. LEVEL OF EVIDENCE: IV, retrospective cohort study.