Analysis of the effects of MIPPO under the anterolateral approach on stress indicators and ankle joint function in patients with open fracture of tibia and fibula

Abstract

Background

To compare clinical application value of minimally invasive percutaneous plate osteosynthesis (MIPPO) through anterolateral approach and conventional posterolateral approach, and conduct retrospective analysis of MIPPO surgical methods through different approaches in patients with open tibial and fibular fractures (OTFF), to supply reference for clinical operations.

Methods

A retrospective analysis was implemented on 84 patients with distal OTFF divided into groups according to different approaches for MIPPO surgery. Patients who received MIPPO treatment through anterolateral approach were in observation group (n = 42), and patients who received MIPPO treatment through conventional posterolateral approach were in the control group (n = 42). The surgical effects, surgical indicators, American Orthopedic Foot and Ankle Society Scoring System (AOFAS) ankle-foot scale scores, stress indicators [substance P (SP), interleukin-6 (IL-6), prostaglandin E2 (PGE2), procalcitonin (PCT) levels, incidence of complications.

Results

The excellent and good rate of surgery in observation group was 95.24% (40/42); AOFAS score of observation group was higher than that of control group 1 month and 3 months after surgery (P < 0.05); surgical indicators of observation group were better than those of control group (P < 0.05); serum SP, IL-6, PGE2, and PCT levels of observation group were lower than those of control group on 1 and 3 days after surgery (P < 0.05); incidence rate of complications in observation group was 4.76% (2/42).

Conclusion

Compared with conventional posterolateral approach MIPPO for treatment of patients with distal OTFF, application of anterolateral approach MIPPO has more advantages in optimizing surgical indicators, reducing complications, improving surgical results, and improving ankle joint function, and less stress on body, it has advantages of less trauma and high safety and is worthy of clinical promotion and application.

Background

In modern societies, high-energy transportation and industrial accidents have led to an increase in trauma incidence, which accounts for one-third of global physical disabilities [1, 2]. Transportation accidents and workplace injuries are the leading causes of unintentional traumatic events and rank fifth among global risk factors for disability [3]. Falls represent another major cause and are a leading factor in mortality among older adults, with a prevalence of falls exceeding 30% for individuals over 65 years of age and 50% for those over 80 years of age [4–6]. Additionally, falls pose a significant risk for hospitalization, accounting for 40% of emergency department visits in the United States. However, the findings of some studies that selectively report the incidence of falls may obscure the true rate [7, 8].

Traumatic fractures are often caused by accidents, and more than 1 million people die each year from road traffic injuries, especially in low- and middle-income countries [9]. These fractures impose significant socioeconomic burdens and necessitate prompt treatment to avert complications such as infections, nonunion, and even mortality [10]. Among extremity fractures, tibiofibular fractures are the most prevalent, comprising 9–14% of all fractures. They are generally caused by high-energy trauma (e.g., traffic accidents, workplace injuries) or indirect violent injuries (e.g., falls, drops) [11]. Tibiofibular fractures predominantly occur in children and adolescents, with the highest incidence in the middle and lower 1/3 of the tibia. Fractures in unstable regions, such as the distal tibia and fibula, often result in complications like delayed healing [12, 13]. Open fractures are more likely to occur due to the daily physiological functions of the lower extremity and the specific anatomical characteristics, including limited soft tissue coverage [14]. Statistically, open tibial and fibular fractures (OTFF) account for approximately 75% of all tibiofibular fractures, with Gustilo II and III injuries representing about 60% [15, 16].

With the advancement of minimally invasive concepts and techniques, as well as the evolution of fracture fixation principles from the AO principle to the BO principle, minimally invasive surgery is increasingly employed in the treatment of limb fractures. The minimally invasive percutaneous plate osteosynthesis (MIPPO) technique has been developed, and its clinical efficacy is widely recognized. For patients with distal OTFF, surgical intervention is typically required, with MIPPO being the most common approach due to its convenient operation and rapid postoperative recovery [17, 18]. Studies indicate that MIPPO is associated with a shorter operation time and aesthetically pleasing results when treating fractures [19]. For elderly patients with fractures, early functional exercise significantly impacts the recovery of ankle joint function. MIPPO technology can notably reduce postoperative pain, facilitate early passive joint movement, and help prevent joint adhesion and stiffness [20]. Precautions for the MIPPO technique include: limited exposure at the distal end of the incision; a risk of difficulty in medial support reconstruction for patients lacking medial column support; the necessity for a comprehensive preoperative assessment to develop a personalized surgical plan; and the use of closed reduction during the procedure, which places higher demands on the surgeon and should be performed by an experienced physician.

Common approaches for MIPPO surgery include the anterolateral approach, the posterolateral approach, etc. However, different surgical approaches can have different effects on the surgical results. At the same time, some scholars have suggested that adopting a reasonable surgical approach to perform surgery will not only help provide a clear surgical field but also maximize the protection of peripheral nerves and soft tissues [21]. Therefore, it is particularly important to choose a reasonable surgical approach to perform MIPPO. Other studies have pointed out that fractures are persistent stress events that can cause the body to secrete a large number of stress factors, and surgery, as a stress source, can also aggravate the body’s stress state [22]. However, which of the above approaches is used to carry out MIPPO treatment for patients with distal OTFF has less impact on the body’s stress state, and there are few clinical reports. Therefore, this study aims to compare the clinical application value of MIPPO through the anterolateral approach and the conventional posterolateral approach. A retrospective analysis and comparative study of different approaches to MIPPO surgery performed on patients with distal OTFF was conducted to provide a reference for selecting optimal surgical approaches in distal OTFF.

Methods and materials

Basic information

A retrospective analysis was conducted on 84 patients with distal OTFF who were treated in our hospital from January 2022 to January 2024 and were divided into groups according to the different approaches of MIPPO surgery performed by the patients. Patients who received MIPPO treatment through the anterolateral approach were in the observation group (n = 42), and patients who received MIPPO treatment through the conventional posterolateral approach were in the control group (n = 42). There were 25 males and 17 females in the observation group; their ages ranged from 36 to 64 years old, with an average age of (48.93 ± 6.11) years. Injury factors: 10 cases were injured by smashing, 12 cases were injured by falling from a height, and 20 cases were injured by traffic accidents. Ruedi-Allgower classification: 15 cases were type I, 18 cases were type II, and 9 cases were type III; the time from fracture to admission was 1 to 8 h, with an average of (4.47 ± 1.42) hours. There were 26 males and 16 females in the control group; their ages ranged from 35 to 64 years old, with an average age of (48.64 ± 6.25) years. Injury factors: 8 cases were injured by smashing, 15 cases were injured by falling from a height, and 19 cases were injured by traffic accidents. Ruedi-Allgower classification: 13 cases were type I, 20 cases were type II, and 10 cases were type III; the time from fracture to admission was 1 to 8 h, with an average of (4.41 ± 1.17) hours. The basic information of the two groups of patients was comparable (P > 0.05). The study was approved by the Fuzhou First People’s Hospital. Written informed consent was obtained from all individuals included in this study.

Inclusion and exclusion criteria

Inclusion criteria

Distal OTFF confirmed by X-ray, MRI, and other examinations; fresh unilateral fracture; signed informed consent.

Exclusion criteria

Combined blood, endocrine, and immune system diseases; other types of fractures; poor compliance; previous OTFF surgery history; allergic constitution; malignant tumors; history of mental illness; not accepting follow-up and lost to follow-up.

Methods

Observation group

Received anterolateral approach MIPPO treatment, epidural anesthesia, supine position, and an arc-shaped longitudinal surgical incision from top to bottom from 1 cm from the front edge of the fibula to the medial malleolus. Use a sharp round knife to separate the fracture site from the superficial fascia of the skin as much as possible. The superficial peroneal nerve is protected with a skin graft. The extensor digitorum longus and intermuscular approach (anterolateral) are taken to expose the fibular window. The fracture end is then fixed with a locking plate. Cut off the upper retinaculum of the extensor muscles, pull the vascular nerve bundle, tibialis anterior muscle, and extensor digitorum longus muscle medially, and separate them to expose the joint surface (distal end); pry the reduction (with Kirschner wires) and fix it. If there is a metaphyseal defect, bone grafting will be performed. After satisfactory fluoroscopy (assisted by a C-arm machine), an L-shaped steel plate will be removed to fix it, the deep fascia and upper extensor retinaculum will be repaired, and the wound will be rinsed and sutured.

Control group

Received conventional posterolateral approach MIPPO treatment, epidural anesthesia, supine position, a surgical incision (longitudinal) is made between the Achilles tendon and the lateral side of the fibular spine, the longus and brevis muscles are bluntly separated, the joint capsule and tibiotalar joint surface are exposed, and temporary reduction is performed (with Kirschner wires). If there is a metaphyseal defect, bone grafting is performed, a soft tissue tunnel is established, a locking plate is taken, inserted from the distal end to the medial side of the distal tibia, and advanced toward the proximal end. According to the specific situation, take 3 or more screws and drive them into the distal and proximal ends, respectively, and fix them. The wound will be rinsed, sutured, and bandaged with pressure.

Observation indicators

Surgical effects

All were evaluated 3 months after surgery. Evaluation criteria: Excellent: Clinical symptoms disappear, American Orthopedic Foot and Ankle Society Scoring System (AOFAS) Ankle-Foot Rating Scale score > 90 points; Good: Clinical symptoms improved, AOFAS score 80 to 90 points; Poor: Inconsistent with the above standards; excellent and good are included in the excellent and good rate of surgery.

Ankle joint function

The AOFAS score was used to appraise the ankle joint function of the two groups before surgery, 1 month, and 3 months after surgery, with a total of 100 points. The score is directly proportional to the ankle joint function.

Surgical indicators

Include fracture healing time, operation time, and intraoperative blood loss.

Stress indicators

2 ml of venous blood was collected from both groups before surgery, 1 day, and 3 days after surgery, and centrifuged at 3,000 r/min for 10 min (r = 10 cm). Serum was collected and enzyme-linked immunoassay was used to decide serum substance P (SP), interleukin-6 (IL-6), prostaglandin E2 (PGE2), and procalcitonin (PCT) levels.

Complication rate

Including delayed fracture healing, skin edge necrosis, wound infection, internal fixation exposure, etc.

Statistical method

SPSS 26.0 software was used to process data. Count data were described by the number of cases (n), and the χ² test was used; the measurement data were subjected to Bartlett’s homogeneity of variance test and Kolmogorov-Smirnov normality test, both of which were confirmed to have homogeneity of variances and approximately obey a normal distribution, and were described as mean ± SD (). Comparisons between two groups were implemented using independent sample t-tests, and comparisons within groups were implemented using paired t-tests. P < 0.05 indicated statistically significant differences.

Results

Comparison of excellent and good rates between two surgical techniques

In the observation group, 17 cases had excellent treatment results, 23 cases had good results, and 2 cases had poor results. The overall excellent and good rate was 95.24%; in the control group, 11 cases had excellent treatment results, 22 cases had good results, and 9 cases had poor results. The overall excellent and good rate was 78.57%. Comparing the two groups, the treatment effect of the observation group was more obvious (P < 0.05) (Table 1; Fig. 1).

Table 1.

Comparison of surgical effects (n,%)

Group	Excellent	Good	Poor	Excellent and good rate
observation group (n = 42)	17 (40.48)	23 (54.76)	2 (4.76)	40 (95.24)
control group (n = 42)	11 (26.19)	22 (52.38)	9 (21.43)	33 (78.57)
χ2				5.126
P				0.024

Fig. 1.

Bar plot comparing surgical results

Comparison of AOFAS scores between the two groups of patients

There was no difference in AOFAS scores between the two groups of patients before surgery (P > 0.05). One month after surgery, the AOFAS scores of both groups were higher than before surgery, and the observation group was higher than the control group (P < 0.05); AOFAS scores were higher 3 months after surgery than 1 month after surgery, and the observation group was higher than the control group (P < 0.05) (Table 2; Fig. 2).

Table 2.

AOFAS score comparison (, points)

Group	Before surgery	1 month after surgery	3 months after surgery
Observation group (n = 42)	46.71 ± 5.08	62.48 ± 6.90	90.95 ± 6.87
Control group (n = 42)	46.85 ± 5.34	54.79 ± 5.71	81.86 ± 6.19
t	-0.123	5.564	6.370
P	0.902	0.000	0.000

Fig. 2.

AOFAS score comparison

Comparison of surgical indicators between the two groups of patients

There was no difference in operation time between the two groups of patients (P > 0.05). The fracture healing time in the observation group was shorter than that in the control group, and the intraoperative blood loss was lower than that in the control group (P < 0.05) (Table 3; Fig. 3).

Table 3.

Comparison of surgical indicators ()

Group	Fracture healing time (weeks)	Surgery time (min)	Intraoperative blood loss (ml)
Observation group (n = 42)	12.55 ± 1.17	75.36 ± 10.08	86.48 ± 5.66
Control group (n = 42)	15.52 ± 1.23	72.21 ± 10.54	105.90 ± 7.05
t	-11.338	1.400	-13.921
P	0.000	0.165	0.000

Fig. 3.

Comparison of surgical indicators

Comparison of stress indicators between the two groups of patients

There was no difference in serum SP, IL-6, PGE2, and PCT levels between the two groups of patients before surgery (P > 0.05). One day after the operation, the serum SP, IL-6, PGE2, and PCT levels of the two groups of patients were all higher than those before the operation, and the observation group was lower than the control group (all P < 0.05) (Table 4; Fig. 4); the serum SP, IL-6, PGE2, and PCT levels of the two groups of patients 3 days after surgery were all lower than those 1 day after surgery, and the observation group was lower than the control group (all P < 0.05) (Table 4; Fig. 5).

Table 4.

Comparison of stress indicators ()

Time	Group	SP (ug/l)	IL-6 (pg/ml)	PGE2 (pg/ml)	PCT (ng/ml)
Before surgery	observation group (n = 42)	13.56 ± 1.84	11.90 ± 2.05	165.35 ± 18.20	12.58 ± 2.30
	control group (n = 42)	13.60 ± 1.68	12.20 ± 2.20	163.58 ± 16.55	11.98 ± 2.05
	t	-0.104	-0.647	0.466	1.262
	P	0.917	0.520	0.642	0.210
1 day after surgery	observation group (n = 42)	20.05 ± 2.35*	22.05 ± 3.05*	245.50 ± 20.05*	18.35 ± 2.33*
	control group (n = 42)	24.55 ± 3.50*	26.13 ± 4.02*	284.26 ± 21.26*	24.06 ± 3.59*
	t	-6.918	-5.240	-8.596	-8.646
	P	0.000	0.000	0.000	0.000
3 days after surgery	observation group (n = 42)	16.14 ± 1.98*	17.08 ± 2.06*	187.16 ± 15.10*	14.68 ± 2.55*
	control group (n = 42)	20.06 ± 3.05*	20.65 ± 2.62*	235.56 ± 26.50*	19.05 ± 3.25*
	t	-6.986	-6.942	-10.284	-6.856
	P	0.000	0.000	0.000	0.000

Compared with the same group before surgery, ^*P < 0.05

Fig. 4.

Comparison of stress indicators 1 day after surgery

Fig. 5.

Comparison of stress indicators 3 days after surgery

Comparison of the incidence of complications between the two groups of patients

Only one patient in the observation group suffered from wound infection complications, and the overall complication rate was 4.76%; in the control group, 4 patients had delayed healing, 2 had skin edge necrosis, 3 had wound infection, and 1 had internal fixation exposure. The overall complication rate was 23.81%. By comparing the two groups of patients, the results showed that the observation group had a lower incidence of complications (P < 0.05) (Table 5).

Table 5.

Complication rate comparison (n, %)

Group	Delayed healing	Skin edge necrosis	Wound infection	Exposed internal fixation	Complication rate
Observation group (n = 42)	0	0	2 (4.76)	0	2 (4.76)
Control group (n = 42)	4 (9.52)	2 (4.76)	3 (7.14)	1 (2.38)	10 (23.81)
χ2					6.222
P					0.013

Discussion

OTFF accounts for about 8-10% of all fractures in the human body. The tibia and fibula, located in the lower leg, are particularly susceptible to direct violent injuries [23]. Most OTFFs are associated with damage to the local skin and subcutaneous tissue. The posterior tibia is primarily covered by muscles and other soft tissues, while the anterior 1/3 of the tibia is only protected by skin and a minimal amount of soft tissue. Due to this limited soft tissue coverage, along with poor local blood supply, post-traumatic inflammatory reactions, and compromised blood flow following swelling, the risk of skin necrosis and poor wound healing at the fracture site increases [24]. OTFF is mostly caused by high-energy damage to the body. In recent years, with the increase in the development of transportation and industry, the incidence of OTFF has also been increasing year by year, causing great pain to patients and affecting their quality of life [25]. In recent years, MIPPO has been used as a minimally invasive surgical technique when distal tibia fractures occur. A longitudinal incision of approximately 3 cm is made along the medial malleolus of the tibia of the affected limb to separate the subcutaneous tissue. After closed reduction, a locking plate is introduced along the periosteum surface, and 3–5 locking screws are placed off the fracture to complete the reconstruction of the stability of the fracture end. Because of its small incision and less trauma, it does not interfere with the blood supply of the fracture end and is more in line with biological principles. When treating OTFF, MIPPO has the advantages of being minimally invasive, more in line with biological fixation requirements, improving fracture healing rate, reducing soft tissue damage, and reducing postoperative complications [26], making it an effective method for treating OTFF.

MIPPO is a commonly used surgical procedure for the clinical treatment of distal OTFF. There are many surgical approaches for this procedure, including the anterolateral approach, the posterolateral approach, etc. However, there are certain differences in the surgical effects of different approaches [27]. Therefore, how to choose a reasonable surgical method to carry out MIPPO to treat patients with distal OTFF has become a hot topic in clinical research. The results of this study show that the excellent and good rate of surgery in the observation group was 95.24%, which was higher than that in the control group (78.57%). The surgical indicators of the observation group were better than those of the control group, and the postoperative AOFAS score was higher than that in the control group (P < 0.05). It shows that the application of MIPPO under the anterolateral approach to treating patients with distal OTFF is more helpful in improving the surgical effect, reducing intraoperative blood loss, and promoting ankle joint function recovery and fracture healing. Conventional posterolateral approach surgery has long incisions and requires extensive dissection of the body’s soft tissues, which in turn affects the surrounding blood supply. At the same time, it is easy to aggravate the degree of soft tissue damage, resulting in greater intraoperative blood loss; it also damages the fracture healing microenvironment and causes complications such as delayed fracture healing, which is not conducive to the patient’s postoperative recovery. The anterolateral side has rich muscle tissue, which can better cover the fractured end of the fibula. MIPPO is performed through the anterolateral approach, which is performed in the intermuscular space, and it is not easy to deprive the muscle, soft tissue, and skin flap. Therefore, it can better protect the blood supply around the anterior tibial artery and the distal tibia, avoid damage to the blood supply at the fracture end, effectively reduce intraoperative bleeding, and provide an excellent microenvironment for postoperative fracture healing. At the same time, the internal fixation is placed through the anterolateral incision and can also be covered by the anterolateral extensor muscles, thereby effectively preventing the internal fixation from being exposed and being more in line with human biology. In addition, the data of this study also showed that the incidence of complications in the observation group was 4.76%, which was lower than 23.81% in the control group (P < 0.05). It is suggested that MIPPO treatment for patients with distal OTFF through the anterolateral approach has more advantages in reducing complications and improving surgical safety. This may be because this approach can minimize soft tissue damage and better protect the blood supply around the distal tibia.

Studies have found that fractures and postoperative local swelling and pain are mainly caused by traumatic inflammation. After the human body is stimulated by factors such as trauma, the body will undergo an inflammatory response. Among the basic pathological changes of inflammation, deterioration, and exudation are related to local swelling. During the inflammatory reaction, the tendency, activation, and vascular response of leukocytes and other immune cells are achieved through the action of a series of inflammatory factors, among which tumor necrosis factor, interleukin, etc., play an important role. OTFF can choose surgical treatment. On the one hand, surgical treatment can stabilize the fracture end and provide an environment for tissue repair. On the other hand, the surgery itself will cause a “second blow” to the local tissue. For example, intraoperative peeling of soft tissue, use of electrosurgery, and implantation of implants can cause tissue damage and promote the secretion and trend of inflammatory factors, thereby further aggravating the inflammatory response [28]. Other literature reports that excessive stress is one of the important changes after fracture patients suffer energy trauma and surgical trauma. It can cause the body’s serum SP, IL-6, PGE2, and PCT to be overexpressed, thus affecting the patient’s postoperative recovery [29]. Serum IL-6 and PCT are common clinical inflammatory stress factors. When overexpressed, it indicates an aggravation of the body’s inflammatory stress state. Serum SP and PGE2 are common clinical pain stress factors. Fracture itself and surgical trauma can cause excessive secretion of serum SP and PGE2 in the body, which can aggravate the local pain stress state [30]. To validate the influence of the chosen surgical approach on operative stress, we analyzed postoperative CRP, PCT, SP, IL-6, and PGE2 concentrations in blood serum. The results of this study showed that the postoperative serum SP, IL-6, PGE2, and PCT levels of the observation group were lower than those of the control group (P < 0.05). This objectively confirms that compared with conventional posterolateral approaches to treating patients with distal OTFF, MIPPO treatment through the anterolateral approach has less stress on the body. This is mainly because this approach is carried out through the muscle gap, which can avoid excessive stripping of peripheral nerves and soft tissues, is less destructive, and has less impact on the body’s stress state. In addition, it is important to note that some of these markers, such as PCT, are strongly associated with infection rather than surgical injury itself. Given that our study includes open fractures, the potential for wound infection and its impact on postoperative stress levels should be considered. Future studies should include a detailed analysis of the body’s response to pathogens inhabiting the fracture site to better understand the overall postoperative stress response.

In summary, the application of the anterolateral approach for MIPPO in treating patients with distal OTFF is beneficial in optimizing surgical indicators, enhancing surgical outcomes, reducing complications, and promoting the recovery of ankle joint function. This approach offers advantages such as reduced trauma and high safety, making it worthy of clinical promotion. However, there are some limitations to this study. First, the retrospective nature of this study limits the level of evidence due to the lack of randomization. Future studies should consider a prospective randomized controlled trial design to better control confounding variables and provide stronger evidence. Second, the relatively short follow-up period of 3 months limited our ability to assess long-term complications and functional outcomes. Longer-term follow-up (12–24 months) is necessary to fully assess the durability of surgical outcomes and potential late complications. Third, due to the retrospective nature of this study, detailed radiologic analyses of the patients, such as X-ray imaging, were not available. This limited our ability to fully assess fracture healing and alignment. Future studies should include detailed radiologic analyses, such as preoperative and postoperative radiographic imaging, to better assess fracture reduction, alignment, and healing. This would provide a more comprehensive assessment of surgical outcomes.

Abbreviations

MIPPO

Minimally invasive percutaneous plate osteosynthesis

OTFF

Open tibial and fibular fractures

AOFAS

American Orthopedic Foot and Ankle Society Scoring System

SP

Substance P

IL-6

Interleukin-6

PGE2

Prostaglandin E2

PCT

Procalcitonin

AI

Accidental trauma

Authors’ contributions

ZHW is responsible for the guarantor of integrity of the entire study, study concepts & design, definition of intellectual content, literature research, clinical studies, experimental studies, data acquisition & analysis, statistical analysis, manuscript editing & review; PPX is responsible for the guarantor of integrity of the entire study, study concepts, study design, literature research, clinical studies, experimental studies, data acquisition & analysis, statistical analysis, manuscript preparation & editing & review; JJL is responsible for the guarantor of integrity of the entire study, study concepts, definition of intellectual content, literature research, clinical studies, experimental studies, literature research, clinical studies, experimental studies, data acquisition & analysis, statistical analysis, manuscript preparation & editing & review. All authors read and approved the final manuscript.

Funding

The authors have not received any funding support.

Data availability

All data generated or analysed during this study are included in this. Further enquiries can be directed to the corresponding author.

Declarations

Ethics approval and consent to participate

The study was approved by the Fuzhou First People’s Hospital. Written informed consent was obtained from all individuals included in this study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.