Posterior Arthroscopic Reduction and Internal Fixation for Treatment of Posterior Malleolus Fractures

A systematic review of posterior pilon variant fractures

Posterior pilon variant ankle fractures (PPVF) are a unique subtype of posterior malleolar fractures which have been a source of controversy and confusion in recent years. There has not been a thorough literature review previously written on the topic. Database searches of PubMed and Embase were conducted from inception until June 2023. The key words included "pilon variant," "posterior pilon variant," and "posterior pilon" fractures. Outcomes were evaluated by union time, rates of delayed union, nonunion, malunion, and complication. A total of 15 articles relevant to surgical repair of pilon variant fractures were included in the literature review. The unique mechanism of injury has been reported to involve both rotational and axial forces, leading to involvement of the posterior and medial aspects of the distal tibia. Pilon variant fractures can be suspected by several characteristics on radiographs and have a high confirmation rate via CT images. Multiple systems have been proposed to classify this fracture pattern, but there is no consensus on the ideal classification system. Surgically, direct fixation has shown better short-term clinical outcomes versus indirect fixation or no fixation. PPVF have a distinct fracture pattern involving the posterior and medial columns of the distal tibial plafond, and results from a mechanism intermediate to rotational and axial forces. These fractures are more severe than tri-malleolar fractures due to increased rates of articular impaction and incongruity. Future classification systems should focus on joint surface area and the tibial pilon column involved to avoid confusion with less severe posterior malleolar fractures.

Serum caspase‑1 levels serve as a predictive biomarker for the prognosis of patients undergoing arthroscopic‑assisted locking plate internal fixation in the treatment of high‑energy pilon fractures

The present study aimed to investigate the serum levels of caspase-1 in patients with high-energy pilon fractures, and its correlation with prognosis and clinical results. In this prospective study, 136 patients with high-energy pilon fractures who were treated with a locking plate combined with ankle arthroscopy from July 2015 to July 2020 were included. The treatment efficacy was evaluated according to the Mazur ankle function score. Serum caspase-1, interleukin (IL)-6, IL-1β and C-reactive protein (CRP) levels were measured using enzyme-linked immunosorbent assay. Reverse transcription-quantitative PCR was used to measure the mRNA expression of caspase-1. Additionally, demographic data and clinical characteristics, such as sex, age, intraoperative blood loss, fracture healing time, fracture classification and complications were collected and analyzed. The study revealed that the intraoperative blood loss, proportion of Ruedi-Allgower III and the serum levels of caspase-1 in the poor prognosis group were significantly higher compared with those in the good prognosis group. Additionally, patients with high-energy pilon fractures in the poor prognosis group exhibited significantly higher levels of caspase-1 and IL-1β serum levels at all time points in contrast to those in the good prognosis group. Spearman's analysis revealed a significant association between caspase-1, IL-1β levels and Mazur scores. Furthermore, caspase-1 could serve as a potential diagnostic biomarker for poor prognosis of patients with high-energy pilon fractures. Caspase-1, IL-1β, intraoperative blood loss and Ruedi-Allgower grade were the risk factors for poor prognosis in patients with high-energy pilon fractures. In summary, this study demonstrated that serum caspase-1 levels were progressively reduced during the treatment of high-energy pilon fractures patients and prominently lowered in those with a favorable prognosis. These findings could provide novel targets and a comprehensive approach to protecting patients with high-energy pilon fractures.

Risks Associated With Posterior Ankle Hindfoot Arthroscopy Complications

BACKGROUND

The use of posterior ankle and hindfoot arthroscopy (PAHA) has been expanding over time. Many new indications have been reported in the literature. The primary objective of this study was to report the rate of PAHA complication in a large cohort of patients and describe their potential associations with demographical and surgical variables.

METHODS

In this IRB-approved retrospective comparative study, patients who underwent posterior ankle and/or hindfoot arthroscopy in a single institution from December 2009 to July 2016 were studied. Three fellowship-trained orthopaedic foot and ankle surgeon performed all surgeries. Demographic data, diagnosis, tourniquet use, associated procedures, and complications were recorded. To investigate a priori factors predictive of neurologic complication after PAHA, univariate and multivariable logistic regression was utilized. Where appropriate, sparse events sensitivity analysis was tested by fitting models with Firth log-likelihood approach.

RESULTS

A total of 232 subjects with 251 surgeries were selected. Indications were posterior ankle impingement (37%), flexor hallux longus disorders (14%), subtalar arthritis (8%), and osteochondral lesions (6%). Complications were observed in 6.8% (17/251) of procedures. Neural sensory lesions were noted in 10 patients (3.98%), and wound complications in 4 ankles (1.59%). Seven neurologic lesions resolved spontaneously and 3 required further intervention. In a multivariable regression model controlled for confounders, the use of accessory posterolateral portal was the significant driver for neurologic complications (odds ratio [OR] 32.19, 95% CI 3.53-293.50).

CONCLUSION

The complication rate in this cohort that was treated with posterior ankle and/or hindfoot arthroscopy was 6.8%. Most complications were due to neural sensorial injuries (sural 5, medial plantar nerve 4, medial calcaneal nerve 1 ) and 3 required additional operative treatment. The use of an accessory posterolateral portal was significantly associated with neurologic complications. The provided information may assist surgeons in establishing diagnoses, making therapeutic decisions, and instituting surgical strategies for patients that might benefit from a posterior arthroscopic approach.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Biomechanical guidance can improve accuracy of reduction for intra-articular tibia plafond fractures and reduce joint contact stress

Articular fracture malreduction increases posttraumatic osteoarthritis (PTOA) risk by elevating joint contact stress. A new biomechanical guidance system (BGS) that provides intraoperative assessment of articular fracture reduction and joint contact stress based solely on a preoperative computed tomography (CT) and intraoperative fluoroscopy may facilitate better fracture reduction. The objective of this proof-of-concept cadaveric study was to test this premise while characterizing BGS performance. Articular tibia plafond fractures were created in five cadaveric ankles. CT scans were obtained to provide digital models. Indirect reduction was performed in a simulated operating room once with and once without BGS guidance. CT scans after fixation provided models of the reduced ankles for assessing reduction accuracy, joint contact stresses, and BGS accuracy. BGS was utilized 4.8 ± 1.3 (mean ± SD) times per procedure, increasing operative time by 10 min (39%), and the number of fluoroscopy images by 31 (17%). Errors in BGS reduction assessment compared to CT-derived models were 0.45 ± 0.57 mm in translation and 2.0 ± 2.5° in rotation. For the four ankles that were successfully reduced and fixed, associated absolute errors in computed mean and maximum contact stress were 0.40 ± 0.40 and 0.96 ± 1.12 MPa, respectively. BGS reduced mean and maximum contact stress by 1.1 and 2.6 MPa, respectively. BGS thus improved the accuracy of articular fracture reduction and significantly reduced contact stress. Statement of Clinical Significance: Malreduction of articular fractures is known to lead to PTOA. The BGS described in this work has potential to improve quality of articular fracture reduction and clinical outcomes for patients with a tibia plafond fracture.

Use of an aiming drill guide and ankle arthroscopy for reduction of depressed articular surface in posterior malleolar fractures

PURPOSE

We describe a novel technique that uses an aiming drill guide and ankle arthroscopy for direct visualization and reduction of the depressed articular surface located between the posterior tibia and the fractured posterior malleolus. This technique requires less soft tissue dissection to visualize and reduce the depressed articular surface.

METHODS

Between June 2014 and May 2019, 126 patients were surgically treated for trimalleolar fractures. Among them, 11 had depressed articular fragment between the posterior tibia and the fractured posterior malleolus reduced using our novel technique. The study included six men and five women, with a mean age of 46.5 (range: 23-62) years.

RESULTS

In eight (73%) cases, the articular surface was reduced, with the articular surface step-off being less than 2 mm, as noted on postoperative computed tomography (CT). Syndesmosis congruity within an anterior-to-posterior difference of less than 2 mm was confirmed in nine (82%) cases via postoperative CT. The mean 100-mm visual analog scale (VAS) and the mean Olerud-Molander ankle score at the final follow-up were 16.6 ± 14.5 and 87.7 ± 7.5, respectively.

CONCLUSIONS

The depressed articular fragment located between the posterior tibia and the fractured posterior malleolus can be treated using an aiming drill guide and ankle arthroscopy. Ankle arthroscopy is used for direct visualization of the depressed articular surface, and the aiming drill guide can guide the bone plunger precisely to the depressed articular surface for reduction. This technique requires less soft tissue dissection than conventional techniques to visualize and reduce the depressed articular surface.