Ethical statement
The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The trial was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was reviewed approved by the ethics committee of the Second Affiliated Hospital of Soochow University, and informed consent was taken from all individual participants.
Baseline clinical data
Sixty patients with supination-external rotation type IV ankle fractures treated in our hospital from February 2018 to August 2020 were enrolled. According to the different surgical approaches, they were divided into anterolateral approach group and posterolateral approach group. The baseline clinical characteristics of the two groups are shown in Table 1.
Inclusion and exclusion criteria
Inclusion criteria were as follows:
- Unilateral fresh closed fracture
- Supination-external rotation type IV ankle fracture
- All procedures performed by the same surgeon (Bo Jiang)
- Complete follow-up data
- Approval by the medical ethics committee of our hospital
- Patient’s understanding of the purpose and significance of the study and voluntary participation
Exclusion criteria were as follows:
- Soft tissue/skin damage or open fracture
- Inability to tolerate surgery
- Other fresh fractures or neuromuscular injuries on the affected side of foot
- Metabolic or pathological fractures
Surgical technique in the anterolateral approach group
Continuous epidural or general anesthesia was administered. Patients were placed in the supine position, and routine disinfection of the surgical area was performed. In air bag tourniquet was used for all procedures. A longitudinal incision was made at the anterior edge of the distal fibula, with the distal end of the incision pointing to the base of the fourth metatarsal (Fig. 1). The length of the incision was determined based on the fracture site and degree of comminution. The fractured end of the lateral malleolus was exposed layer by layer and cleaned thoroughly, following which it was reduced and fixed with plates and screws. The posterior malleolus fracture was then reduced and fixed, and the posterior malleolus fragment was pressed in a posterior-to-anterior direction using a periosteal stripper through the posterior edge of the lateral malleolus (between the lateral malleolus and the long and short tendons of the fibula) in the same incision. Posterior malleolar fracture was fixed with Kirschner wires in an anterior-to-posterior direction. After satisfactory C-arm fluoroscopy, a cannulated screw was used to fix the posterior malleolus fracture. The fractured end of the medial malleolus was exposed via a curved incision of the medial malleolus and fixed with a hollow lag screw following reduction. After fracture reduction and fixation, the anterior inferior tibiofibular ligament (AITLF) and anterior talofibular ligament (ATFL) were repaired via routine exploration using the anterolateral approach.
Surgical technique in the posterolateral approach group
Continuous epidural or general anesthesia was administered. Patients were placed in a prone or contralateral position, and routine disinfection and preparation of the surgical area was performed. Balloon tourniquets were used for all procedures. A longitudinal incision was made between the long and short tendons of the fibula and the Achilles tendon to protect the sural nerve. The muscle of the peroneus longus brevis was pulled posteriorly and medially, and the lateral skin flap was pulled anteriorly and laterally to expose the fractured end of the lateral malleolus, which was then fixed with plates and screws. The flexor pollicis longus muscle was gently pulled inwards to expose the fractured of the posterior malleolus, which was then reduced with the help of ligaments and temporarily fixed with Kirschner wire. After satisfactory C-arm fluoroscopy, the fractured end was fixed with steel plates or screws. A supine position was then adopted in favor of the prone position, and the lower extremities in the contralateral position were rotated externally. A curved incision was used to expose the fractured end of the medial malleolus while taking care to protect the great saphenous vein when exposed, following which the fractured end was fixed with a hollow lag screw after reduction.
Assessment indices
Operation time, intraoperative blood loss, fracture healing time, number of complications, preoperative and postoperative VAS scores, postoperative SF-36 scores, and American Orthopedic Foot and Ankle Society (AOFAS) scores for at least 1 year of follow-up were compared between the two groups. The AOFAS score includes 40 points for pain, 50 points for function, and 10 points for alignment, with a maximum score of 100. Total scores of 90–100, 75–89, 50–75, and <50 indicate excellent, good, fair, and poor outcomes, respectively.
Table 1. Baseline clinical data of the two groups
|
Anterolateral approach
|
Posterolateral approach
|
t/X2
|
P
|
Age (year)
|
52.0±13.8
|
54.2±11.7
|
0.7
|
0.7
|
Sex
|
|
|
0.35
|
0.72
|
Male
|
17
|
19
|
|
|
Female
|
13
|
11
|
|
|
Side
|
|
|
0.33
|
0.74
|
Right
|
17
|
14
|
|
|
Left
|
13
|
16
|
|
|
Etiology
|
|
|
0.039
|
0.998
|
Car accident-related injury
|
17
|
16
|
|
|
Sprain
|
8
|
7
|
|
|
Fall-related injury
|
3
|
4
|
|
|
Others
|
2
|
3
|
|
|
Statistical analysis
Statistical analyses were performed using SPSS Statistics software (version 23.0; SPSS Inc., Chicago, IL, USA). Quantitative variables are expressed as the mean ± standard deviation (SD) and were compared using t-tests. Qualitative variables are expressed as numbers (N) and percentages (%) and were compared using the chi-square test P values <0.05 were considered statistically significant.
Table 2. Comparison of clinical outcomes between two groups
Outcomes
|
Anterolateral approach
|
Posterolateral approach
|
P
|
Operation time (min)
|
86.73±17.44
|
111.23±10.05
|
<0.001
|
Intraoperative blood loss (ml)
|
112.60±25.05
|
149.47±44.30
|
<0.001
|
Fracture healing time (weeks)
|
10.90±0.66
|
11.27±0.94
|
0.087
|
VAS score
|
|
|
|
Preoperative
|
6.33±0.61
|
6.27±0.64
|
0.680
|
Postoperative
|
1.43±0.51
|
1.83±0.75
|
0.020
|
SF-36 score
|
73.63±4.07
|
72.70±4.04
|
0.458
|
AOFAS score
|
80.43±4.32
|
75.43±11.32
|
0.030
|
VAS: visual analog scale; SF-36: Short Form-36 Health Survey; AOFAS: American Orthopedic Foot and Ankle Society