[The Postero-Lateral Approach--An Alternative to Closed Anterior-Posterior Screw Fixation of a Dislocated Postero-Lateral Fragment of the Distal Tibia in Complex Ankle Fractures]

Open Reduction and Internal Fixation of the Posterior Malleolus Fragment in Ankle Fractures Improves the Patient-Rated Outcome: A Systematic Review

BACKGROUND

The best treatment strategy for fractures to the posterior malleolus (PM) is still intensively debated. The aim of this systematic review was to compare the patient-rated outcome following open reduction and internal fixation (ORIF) for fractures of the PM to either closed reduction using AP screws (CRIF) or no treatment in bi- or trimalleolar ankle fractures.

METHODS

Systematic literature research (MEDLINE (PubMed), CINAHL, Scopus, Central and EMBASE) according to the PICOS and PRISMA guidelines. Eligible were studies comparing the outcome following ORIF to any other treatment strategy for fractures to the posterior malleolus in isolated bi- or trimalleolar ankle fractures.

RESULTS

Twelve studies were eligible for a qualitative analysis and 6 for a quantitative analysis. Overall, a considerable heterogeneity among the studies was observed. The most commonly used outcome score was the American Orthopaedic Foot & Ankle Society ankle-hindfoot score (AOFAS). The final follow-up ranged from 12 to 160 months. Four studies compared ORIF to CRIF of the PM. The quantitative analysis revealed significantly better AOFAS scores for ORIF (90.9 vs 83.4 points; P < .001; I2 = 0%). Three studies compared ORIF to untreated PM fragment. The quantitative analysis again revealed superior AOFAS scores for ORIF (92.0 vs 82.5 points; P < .001; I2 = 99%). A similar trend was observed for the Ankle Fracture Scoring System and American Academy of Orthopaedic Surgeons Foot and Ankle Questionnaire scores as well as the quality of reduction.

CONCLUSION

Despite a considerable heterogeneity, the data available point to a superior outcome following ORIF for fractures to the PM when compared to CRIF or no treatment.

How the Direction of Screws Affects the Primary Stability of a Posterior Malleolus Osteosynthesis under Torsional Loading: A Biomechanical Study

Insufficient fixation of a posterior malleolus fracture (PM) can lead to posttraumatic complications such as osteoarthritis and chronic pain. The purpose of this biomechanical study was to test the hypothesis of whether the direction of PM screw fixation has an impact on the primary stability of osteosynthesis of a PM under torsional loading. PM fractures of 7 pairs human cadaveric lower leg specimens were stabilized with posterior to anterior (p.a.) or anterior to posterior (a.p.) screw fixation. Stability of the osteosynthesis was biomechanically tested using cyclic external torsional loading levels, in 2 Nm steps from 2 Nm up to 12 Nm, under constant monitoring with 3D ultrasonic marker (Zebris). The primary stability does not differ between both stabilizations (p = 0.378) with a medium effect size (η2p = 0.065). The movement of the PM tends to be marginally greater for the osteosynthesis with a.p. screws than with p.a. screws. Whether a.p. screws or the alternative p.a. screw fixation is performed does not seem to have an influence on the primary stability of the osteosynthesis of the PM fixation under torsional loading. Although osteosynthesis from posterior seems to be more stable, the biomechanical results in the torsional test show quite equivalent stabilities. If there is no significant dislocation of the PM, a.p. screw fixation could be a minimally invasive but stable surgical strategy.

Evidence-Based Surgical Treatment Algorithm for Unstable Syndesmotic Injuries

Background: Surgical treatment of unstable syndesmotic injuries is not trivial, and there are no generally accepted treatment guidelines. The most common controversies regarding surgical treatment are related to screw fixation versus dynamic fixation, the use of reduction clamps, open versus closed reduction, and the role of the posterior malleolus and of the anterior inferior tibiofibular ligament (AITFL). Our aim was to draw important conclusions from the pertinent literature concerning surgical treatment of unstable syndesmotic injuries, to transform these conclusions into surgical principles supported by the literature, and finally to fuse these principles into an evidence-based surgical treatment algorithm. Methods: PubMed, Embase, Google Scholar, The Cochrane Database of Systematic Reviews, and the reference lists of systematic reviews of relevant studies dealing with the surgical treatment of unstable syndesmotic injuries were searched independently by two reviewers using specific terms and limits. Surgical principles supported by the literature were fused into an evidence-based surgical treatment algorithm. Results: A total of 171 articles were included for further considerations. Among them, 47 articles concerned syndesmotic screw fixation and 41 flexible dynamic fixations of the syndesmosis. Twenty-five studies compared screw fixation with dynamic fixations, and seven out of these comparisons were randomized controlled trials. Nineteen articles addressed the posterior malleolus, 14 the role of the AITFL, and eight the use of reduction clamps. Anatomic reduction is crucial to prevent posttraumatic osteoarthritis. Therefore, flexible dynamic stabilization techniques should be preferred whenever possible. An unstable AITFL should be repaired and augmented, as it represents an important stabilizer of external rotation of the distal fibula. Conclusions: The current literature provides sufficient arguments for the development of an evidence-based surgical treatment algorithm for unstable syndesmotic injuries.

[Comparison of effectiveness between plate and screw internal fixation in treatment of posterior malleolus fractures through posterolateral approach]

Objective

To compare the effectiveness of posterior malleolus fractures treated by plate and screw internal fixation through posterolateral approach.

Methods

The clinical data of 95 patients with posterior malleolus fractures who were admitted between January 2016 and December 2019 and met the selection criteria were retrospectively analysed. They were divided into plate group (44 cases, treated with posterolateral plate internal fixation) and screw group (51 cases, treated with posterolateral screw internal fixation) according to different treatment methods. There was no significant difference in general data between the two groups of patients such as age, gender, cause of injury, side of injury, ankle fracture or injury classification, time from injury to operation, and percentage of posterior ankle fracture area to the distal tibia articular surface ( P>0.05). The operation time, hospital stay, fracture healing time, and surgical complications were compared between the two groups. Imaging examinations (X-ray film, CT scan and reconstruction) were used to assess the reduction quality of ankle fracture, articular congruity, and re-displacement in ankle fracture. At last follow-up, the pain visual analogue scale (VAS) score was used to evaluate the patients' pain, and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was used to evaluate ankle joint function.

Results

Patients in both groups were followed up 6-30 months, with an average of 18.2 months. The operation time of the plate group was significantly longer than that of the screw group ( U=-2.040, P=0.041); there was no significant difference in hospital stay between the two groups ( U=-1.068, P=0.285). Incision swelling occurred in 2 cases in the plate group, sural nerve injury in 3 cases, and traumatic arthritis in 2 cases during follow-up. In the screw group, there were 1, 2, and 2 cases, respectively. The incidence of complications in the two groups (15.9% vs. 9.8%) was not significantly different ( P=0.372). All patients who underwent tibiofibular screw fixation underwent the removal of the tibiofibular screw before taking full weight bearing at 12 weeks after operation, and there was no screw fracture and retention. During the follow-up, there was no infection, re-displacement of fracture, delayed bone union or nonunion, and there was no significant difference in fracture healing time between the two groups ( t=0.345, P=0.731). There was no significant difference between the two groups of reduction quality of ankle fracture and articular congruity evaluation results ( P>0.05). At last follow-up, there was no significant difference in VAS score, AOFAS ankle-hindfoot score and evaluation grade between the two groups ( P>0.05).

Conclusion

Both the plate and screw internal fixation through posterolateral approach can achieve satisfied effectiveness in the treatment of posterior ankle fractures with maintenance of fracture reduction, and recovery of ankle joint function. The screw internal fixation has the advantages of minimal invasion and shorter operation time.

[Ankle fractures in older patients : What should we do differently?]

As a result of the demographic developments ankle fractures in older patients are part of routine trauma surgery. Due to comorbidities, such as diabetes mellitus, reduced bone quality and limited compliance in follow-up treatment, these fractures are prone to complications. The primary goal in the treatment of older patients with ankle fractures is to maintain mobility. In contrast to young patients most fractures are unstable pronation-abduction injuries. In the diagnostics the recognition and optimization of factors influencing the outcome, such as the blood perfusion and the generous use of computed tomography (CT) are recommended. As in the case of younger patients, conservative treatment is reserved for stable fracture forms and, if there are contraindications, should also be initiated in the case of unstable injuries. The choice of approaches is different for surgical treatment, which is adapted to the soft tissues, if necessary minimally invasive and increasingly carried out by a posterolateral approach. The initial transfixation can reduce soft tissue problems. Special surgical techniques and implants that provide a high level of stability, such as dorsal plate positioning, hook plates, angular stable plate systems and intramedullary systems as well as additional options, such as tibia pro fibula constructs are used. Primary retrograde nail arthrodesis is reserved as a salvage procedure only for exceptional cases. As part of the follow-up treatment, an interdisciplinary approach with respect for and optimization of concomitant diseases seems to make sense.

Biomechanical Analysis of Stability of Posterior Antiglide Plating in Osteoporotic Pronation Abduction Ankle Fracture Model With Posterior Tibial Fragment

BACKGROUND

We performed a biomechanical comparison of 2 methods for operative stabilization of pronation-abduction stage III ankle fractures; group 1: Anterior-posterior lag screws fixing the posterior tibial fragment and lateral fibula plating (LSLFP) versus group 2: locked plate fixation of the posterior tibial fragment and posterior antiglide plate fixation of the fibula (LPFP).

METHODS

Seven pairs of fresh-frozen osteoligamentous lower leg specimens (2 male, and 5 female donors) were used for the biomechanical testing. Bone mineral density (BMD) of each specimen was assessed by means of dual-energy x-ray absorptiometry. After open transection of the deltoid ligament, an osteotomy model of pronation abduction stage III ankle fracture was created. Specimens were systematically assigned to LSLFP (group 1, left ankles) or LPPFP (group 2, right ankles). After surgery, all specimens were evaluated via CT to verify reduction and fixation. Axial load was then applied onto each specimen using a servohydraulic testing machine starting from 0 N (Zwick/Roell, Ulm, Germany) at a speed of 10 N/s with the foot fixed in a 10 degrees pronation and 15 degrees dorsiflexion position. Construct stiffness, yield, and ultimate strength were measured and dislocation patterns were documented with a high-speed camera. The normal distribution of all data was analyzed using Shapiro-Wilk test. The group comparison was performed using paired Student t test. Statistical significance was assumed at a P value of .05.

RESULTS

All specimens had BMD values consistent with osteoporosis. BMD values did not differ between the left and right ankles of the same pair ( P = .762). The mean BMD values between feet of men (0.603 g/cm²) and women (0.329 g/cm²) were statistically different ( P = .005). The ultimate strength for LSLFP (group 1) with 1139 ± 669 N and LPPFP (group 2) with 2008 ± 943 N was statistically different ( P = .036) as well as the yield in LSLFP (group 1) 812 ± 452 N and LPPFD (group 2) 1292 ± 625 N ( P = .016). Construct stiffness trended to be higher in group 2 (179 ± 100 kNn) compared to group 1 (127 ± 73 kN/m) but this difference was not statistically significant ( P = .120). BMD correlated with bone-construct failure.

CONCLUSION

Fixation of the posterior tibial edge with a posterolateral locking plate resulted in higher biomechanical stability than anterior-posterior lag screw fixation in an osteoporotic pronation-abduction fracture model.

CLINICAL RELEVANCE

The clinical implication of this biomechanical study is that the posterior antiglide plating might be advantageous in patients with osteoporotic pronation abduction stage III ankle fracture.