Functional assessment and influencing factors after staged functional training in patients with ankle fractures

Abstract

BACKGROUND

The recovery of limb function after ankle fracture surgery is a gradual process. The main purpose of implementing early functional exercise, joint mobility, muscle contraction function, passive ankle flexion and extension exercises, or physical factor therapy techniques is to achieve the rapid recovery of normal physiological limb function. However, currently the most effective rehabilitation training method is staged limb functional exercise, which promotes rapid recovery of limb function while preventing adverse consequences caused by overwork or insufficient training. Staged limb functional exercise divides the rehabilitation process into multiple stages, each of which has specific training objectives and contents. This method helps patients gradually restore limb function. Nevertheless, some patients still exhibit poor limb function after standardized exercise. Therefore, a functional evaluation should be performed to analyze the impact of staged functional training after ankle fracture surgery.

AIM

To perform a functional evaluation and determine the influencing factors of staged functional training in patients with ankle fracture.

METHODS

A retrospective study enrolled 150 patients who underwent surgical treatment for ankle fracture from May 2020 to May 2022 at our hospital. Univariate and multivariate linear regression analyses were performed on general data, functional exercise compliance scale for orthopedic patients, Social Support Rating Scale (SSRS), American Orthopedic Foot and Ankle Score (AOFAS) Ankle-Hindfoot Score, and pain factors [serum bradykinin (BK), prostaglandin E2 (PGE2), 5-hydroxytryptamine (5-HT)].

RESULTS

Based on the AOFAS Ankle-Hindfoot Scale, the cases were divided into the excellent function (n = 111) and ordinary function (n = 39) groups. Univariate analysis revealed that monthly family income, education level, diabetes mellitus, functional exercise compliance scale of orthopedic patients score, SSRS, BK, PGE2, and 5-HT significantly influenced limb function after ankle fracture (P < 0.05); Multiple linear regression analysis showed that the functional exercise compliance scale score, SSRS, BK, PGE2, and 5-HT were independent risk factors affecting functional performance after staged functional exercise (P < 0.05).

CONCLUSION

Exercise compliance, SSRS, and pain level are the independent risk factors affecting functional performance after staged functional training following ankle surgery. Clinical nursing care after ankle surgery should include analgesic and health education measures to ensure optimal recovery of limb function.

Key Words: Ankle fracture, Staged functional training, Ankle function, Serum pain factor

Core Tip: This article examined the functional recovery assessment and influencing factors after implementing staged training exercise for ankle fractures. Social support, exercise compliance, and pain were identified as independent risk factors affecting ankle function recovery. The study findings can provide clear guidance on postoperative care for ankle surgery.

INTRODUCTION

An ankle fracture usually involves the breakage of either or both the tibia (leg bone) and fibula (bone on the outer side of the lower leg). Ankle fractures can be caused by external impact or high-energy injuries, such as falls, sports injuries, vehicular accidents, or other unforeseen situations. Symptoms of ankle fracture include severe pain, swelling, congestion, impaired movement, and joint dislocation. An epidemiological investigation and analysis by Kang et al[1] found that fracture incidence is highest among people aged 40-50 years, accounting for 24.04% in all age groups, with sprains and vehicular accidents being the main causes of fracture.

The treatment of treating ankle fractures depends on the fracture type and location, severity of concomitant injury, and patient’s age and overall health. Surgical methods include external and internal fixation. The goal of treatment is to ensure proper fracture healing, restore joint function, and reduce sequelae. Therefore, postoperative rehabilitation training is essential to restoring the patient’s ankle strength, flexibility, and balance. At present, no unified standard procedure has been established in clinical practice for the rehabilitation training of patients with ankle fracture[2,3]. Routine rehabilitation training usually implements a universal and general treatment strategy without considering the patient’s individual characteristics and condition. This may lead to insufficient training efficacy and failure to meet the unique needs of patients, resulting in unsatisfactory recovery of ankle joint function, lingering pain, and impaired sleep quality[4,5].

Staged functional training refers to gradual adaptive rehabilitation training implemented according to the different stages of patient rehabilitation to restore, improve, or maintain the patient’s body function. This rehabilitation training approach usually involves an individualized plan developed by a professional rehabilitation team according to the patient’s specific condition and rehabilitation needs[6,7]. Staged functional training is progressive, which helps avoid overtraining and excessive fatigue. Furthermore, it helps improve patients’ endurance and adaptability by restoring motor function, strength, balance, and coordination; reducing pain; improving sleep quality; and maximizing the restoration of autonomy in daily life[8]. However, relatively few reports have explored the application of staged functional training in postoperative rehabilitation of patients with ankle fractures in China. In this study, 150 patients with ankle fracture admitted to our hospital from May 2020 to May 2022 were selected by convenience sampling to comprehensively explore the risk factors affecting the results of staged functional training after ankle surgery on ankle function.

MATERIALS AND METHODS

General data

Equation [N = (U²_1-a/2S²)/d², where statistics U_1-α/2 = 1.96, standard deviation S = 10.90, and allowable error d = 1.5] as used to calculate the sample size, and the confidence interval was set at 95%. The minimum sample size obtained was 182 cases, with consideration of a loss-to-follow-up rate of 15%-20%. Data on 150 patients who underwent ankle fracture surgery at The Fourth Hospital of Wuhan from May 2020 to May 2022 were selected.

Inclusion and exclusion criteria

Inclusion criteria: (1) An ankle joint fracture diagnosed by computed tomography (CT), nuclear magnetic resonance imaging; (2) patients undergoing surgical treatment, including fracture reduction, internal fixation, and external fixation; (3) patients with swelling, pain, and limited movement at admission; and (4) patients aged ≥ 18 years.

Exclusion criteria: (1) Patients with pathological fracture; (2) patients who refuse to cooperate with nursing or relevant examinations; (3) patients with secondary osteoporosis; and (4) patients with concurrent serious organic diseases of the heart, liver, kidney, and endocrine system.

Methods

All patients received staged limb function training after surgery, including hospitalization and discharge. The hospitalization period included postoperative 1-2 days, 3-4 days, and 5-7 days. The discharge period included the 2^nd-4^th week, 5^th-8^th week, and 9^th-12^th week postoperatively. The specific steps of the rehabilitation strategy were as follows: (1) 1-2 days postoperatively: The rehabilitation physician and nursing staff guided the patient and his/her family members in the proper way of massaging the ankle joint and toe of the patient to promote blood circulation in the lower extremities and prevent deep vein thrombosis; (2) 3-4 days postoperatively: Passive movement of the ankle joint and toes should be promoted, including ankle flexion, extension, toe flexion, extension, unfolding and retraction. Varus, valgus, and internal and external rotation are prohibited. The passive activity should be performed for 15 minutes twice/day; (3) 5-7 days postoperatively: Depending on the degree of recovery and tolerance of the patient’s ankle joint, the intensity of passive movement was gradually increased to 3 times/day, and the duration of a single activity was increased from 15 minutes to 20-25 minutes. In addition, the patient was instructed to actively perform lower limb-raising exercise and properly perform ankle varus, valgus, and internal and external rotation activities for 15 minutes twice/day. The intensity of activity depended on the patient’s tolerance; (4) 2-4 weeks postoperatively: After the patient was discharged, rehabilitation training was continuously followed up by telephone follow-up, door-to-door guidance, and online WeChat communication. Ankle joint activity was gradually increased to 30 minutes for 3 times/day. Depending on the degree of ankle function recovery and pain, the angle and strength of ankle varus, valgus, and internal and external rotation was appropriately increased to 30 minutes, 3 times/day; (5) 5-8 weeks postoperatively: When the patient could actively walk with crutches and the swelling of the affected area had subsided without apparent pain, the patient was instructed to walk on tiptoe for 20-30 minutes, 1-2 times/day; (6) 9-12 weeks postoperatively: The amount of walking activity, walking time and distance, and amount of landing activity were increased to 30-45 minutes, 2-3 times/day after the patient’s recovery was confirmed on X-ray and CT examination.

Observation indicators

General data: Patients’ sex, age, monthly family income, education level, diabetes mellitus status, body mass index (BMI), Lauge–Hansen classification, and affected side were extracted from medical records.

Functional exercise compliance scale for orthopedic patients: The functional exercise compliance scale for orthopedic patients[9] was used to evaluate patients’ exercise compliance at 12 weeks postoperatively. The scale consists of 15 items on the three dimensions of physical, psychological, and active learning-related exercise compliance. Each item is evaluated using a 4-point scale, with a possible total score of 15-60 points. The higher the score, the higher the patient’s functional exercise compliance.

Social support Rating Scale (SSRS): The SSRS[10] was used to evaluate the patient’s social support at 12 weeks postoperatively. The scale mainly included three dimensions of subjective support (the total score of items 1, 3, 4, and 5), objective support (the total score of items 2, 6, and 7), and support availability (the total score of items 8-10). Items 1-4 and 8-10 are evaluated on a 5-point scale. Items A, B, C, and D4 of item 5 are evaluated on a 4-point scale. If no source is selected for items 6-7, 0 points will be scored; if several sources are identified, what point will be scored? Higher total scores indicate higher social support.

Ankle function: Ankle function was assessed using the American Orthopedic Foot and Ankle Score (AOFAS) Ankle-Hindfoot scoring system[11] at 12 weeks postoperatively, including ankle and plantar flexion angles. Measurements were performed with a protractor, with the patient’s ankle joint in the neutral position designated as 0°. Measurements were performed three times, and the average value of the three measurements was the final measurement result. The scoring system evaluates pain (40 points), function (50 points), and alignment (10 points). Function assesses movement limitation, need for auxiliary support, maximum walking distance, walking surface, sagittal plane movement (flexion and dorsiflexion), hindfoot movement (varus and valgus), and ankle and hindfoot stability (anteroposterior and valgus). The total possible score of the scoring system is 0-100 points. The higher the score, the better the recovery of ankle joint function. The patients were divided based on total score: Those who scored ≥ 90 points were placed in the good function group, and those who scored < 90 points were placed in the general function group.

Serum pain factors: At 12 weeks postoperatively, 4 mL of blood was drawn from the elbow vein on an empty stomach in the morning. The blood sample was sent to the laboratory for centrifugation at 3600 r/min for 10 min. The supernatant was collected and refrigerated in a cryogenic refrigerator at -80°C. Serum bradykinin (BK), prostaglandin (PGE2), and 5-hydroxytryptamine (5-HT) were detected by enzyme-linked immunosorbent assay.

Data collection and quality control

Patients with ankle fracture were enrolled based on the inclusion and exclusion criteria. Before the study, medical staff were trained and assessed in a unified manner. After training, they could participate in the study only after passing the assessment. Consistency in implementing standard operating procedures during data collection, research ethics, and confidentiality requirements were ensured throughout the study. Data were regularly monitored and reviewed for quality and consistency, including double data entries, logicality checks, and outlier detection. Processes for quality control and quality assurance were strictly implemented, including the review of study procedures, standard operating procedures, and data security and integrity.

Statistical analysis

SPSS.26.0 was used to process the data. The Kolmogorov-Smirnov test was performed to validate the normal distribution of the measurement data. The t-test was performed, and data were expressed as mean ± SD. Count data were expressed as number and percentage and analyzed using the χ² test. Binary logistic regression analysis was performed to determine the independent risk factors affecting functional performance after staged functional training following ankle surgery. Statistical significance was indicated by P < 0.05.

RESULTS

Functional evaluation results

Before treatment, there was no statistical significance in the comparison of plantar flexion angle, dorsiflexion angle and AOFAS Ankle-Hindfoot scores of subjects with ankle fracture (P > 0.05); after 1 month and 2 months of intervention, the plantar flexion angle, dorsiflexion angle and AOFAS Ankle-Hindfoot scores of subjects with ankle fracture were significantly higher than those before and after 1 month of intervention (P < 0.05; Table 1).

Table 1 Functional evaluation results of subjects.

Group	Plantarflexion angle			Dorsal extension angle			AOFAS Ankle-Hindfoot Score (points)
	Before intervention	1 month after intervention	3 months after intervention	Before intervention	1 month after intervention	3 months after intervention	Before intervention	1 month after intervention	3 months after intervention
Subject	11.95 ± 2.07	24.41 ± 2.67a	33.91 ± 3.11b	6.53 ± 1.47	11.83 ± 1.92a	15.73 ± 3.26b	53.11 ± 6.01	64.74 ± 6.08a	81.84 ± 10.16b
t value	0.951	8.538	8.975	1.578	7.329	9.772	1.192	4.381	3.839
P value	0.343	< 0.001	< 0.001	0.117	< 0.001	< 0.001	0.235	< 0.001	< 0.001

^aP < 0.05 compared with the same group before intervention.

^bP < 0.05.

AOFAS: American Orthopedic Foot and Ankle Score.

Single factors affecting postoperative functional exercise of ankle fracture

The functional status after staged sexual training following ankle fracture surgery as a dependent variable, whereas sex, age, monthly family income, education level, and presence or absence of diabetes mellitus status, Lauge–Hansen classification, start time of postoperative exercise, BMI, presence of lower tibiofibular fixation, score, and SSRS score, BK, PGE2, and 5-HT were used as independent variables. Univariate analysis showed that monthly family income, education level, diabetes mellitus status, start time of postoperative exercise, lower tibiofibular fixation, functional exercise compliance scale score, SSRS score, BK, PGE2, and 5-HT were all associated with limb function after staged sexual training following ankle fracture surgery (Table 2).

Table 2 Factors influencing limb function after staged functional training.

Independent variables	Grouping	Excellent functional group (n = 111)	General functional group (n = 39)	χ2	P value
Sex	Male	69	19	2.151	0.142
	Female	42	20
Age (years)		46.58 ± 4.35	46.77 ± 4.28	0.236	0.814
Monthly household income (RMB)	≤ 5000	34	19	4.132	0.042
	> 5001	77	20
Educational level	High school and below	42	22	4.070	0.044
	Junior college or above	69	17
Comorbid diabetes	Yes	81	21	4.852	0.028
	No	30	18
Lauge–Hansen classification	Pronation-abduction	31	9	2.269	0.518
	Pronation-external rotation	26	13
	Supination-adduction	29	7
	Supination-external rotation type	25	10
Start time of postoperative exercise (hour)	48-72	69	17	4.070	0.044
	> 72	42	22
BMI (kg/m2)		24.65 ± 3.68	24.74 ± 3.72	0.131	0.896
Lower tibiofibular fixation	Yes	83	22	4.635	0.031
	No	28	17
Functional exercise compliance scale (points)	Male	49.65 ± 9.46	42.36 ± 8.79	4.214	< 0.01
SSRS (points)	Female	30.64 ± 3.45	24.36 ± 2.46	10.461	< 0.01
BK (μg/L)		6.41 ± 1.32	8.75 ± 1.47	9.243	< 0.01
PGE2 (ρg/mL)	≤ 5000	170.66 ± 19.62	214.14 ± 18.70	12.048	< 0.01
5-HT (ng/L)	> 5001	97.84 ± 18.75	121.44 ± 16.38	6.977	< 0.01

Data are expressed as mean ± SD or number. Lauge-Hansen classification: Ankle fracture classification; BMI: Body mass index; SSRS: Social Support Rating Scale; BK: Bradykinin; PGE2: Prostaglandin E2; 5-HT: 5-hydroxytryptamine.

Multiple factors influencing postoperative functional training after ankle fracture surgery

The independent risk factors affecting functionality after staged functional training following ankle surgery were further analyzed. Binary logistic regression analysis was performed using functional status as dependent variable. Monthly family income, education level, diabetes mellitus status, start time of postoperative exercise, tibiofibular fixation, functional exercise compliance scale, SSRS, BK, PGE2, and 5-HT were used as independent variables. The assignment table of variables is detailed in Table 3. The analysis revealed that the functional exercise compliance scale score, SSRS scale score, BK, PGE2, and 5-HT were the independent risk factors associated with postoperative functional training after ankle fracture surgery (Table 4 and Figure 1).

Figure 1 Receiving operator characteristic curves. A: Functional exercise compliance scale; B: Social Support Rating Scale; C: Bradykinin; D: Prostaglandin; E: 5-hydroxytryptamine, the factors affecting functional performance after staged functional training following ankle fracture surgery. The areas under the curve were 0.831, 0.810, 0.705, 0.780, and 0.880 respectively. The 95%CIs were 0.768-0.893, 0.719-0.901, 0.622-0.791, 0.706-0.854, and 0.815-0.945 respectively.

Table 3 Assignment of variables.

Variables		Assignment method
Dependent variable	Functional status	General function group = 1, excellent function group = 0
Independent variables	Monthly household income	≤ RMB 5000 = 1, > RMB 5001 = 0
	Educational level	High school and below = 1, junior college or above = 0
	Comorbid diabetes	Yes = 1, No = 0
	Start time of postoperative exercise	48-72 hours = 1, > 72 hours = 0
	Lower tibiofibular fixation	No = 1, yes = 0
	Functional exercise compliance scale	Input as original value
	SSRS	Input as original value
	BK	Input as original value
	PGE2	Input as original value
	5-HT	Input as original value

SSRS: Social Support Rating Scale; BK: Bradykinin; PGE2: Prostaglandin E2; 5-HT: 5-hydroxytryptamine.

Table 4 Multivariate analysis of factors influencing function after staged functional training following ankle fracture surgery.

Independent variables	β	SE	Wald χ2	P value	OR	95%CI
						Lower limit	Upper limit
Functional Exercise Compliance Scale for orthopedic patients	-4.941	-6.914	-2.967	1.001	-0.247	-4.937	< 0.001
SSRS	-9.664	-12.377	-6.951	1.375	-0.341	-7.026	< 0.001
BK	-9.664	-12.377	-6.951	1.375	-0.341	-7.026	< 0.001
PGE2	-2.995	-5.466	-0.525	1.252	-0.112	-2.392	0.018
5-HT	-11.507	-15.358	-7.655	1.953	-0.289	-5.892	< 0.001

SSRS: Social Support Rating Scale; BK: Bradykinin; PGE2: Prostaglandin E2; 5-HT: 5-hydroxytryptamine. The indicators in this table are only the relevant influencing factors with P < 0.05).

DISCUSSION

Ankle fractures usually involve the tibia and fibula and are commonly caused by falls, sports injuries, and vehicular accidents, among others. Surgical treatment is currently the first-line treatment in clinical practice. However, because of the long postoperative recovery time of ankle fractures, delayed and ineffective rehabilitation training will have adverse effects on ankle functional rehabilitation. Therefore, clinical attention should be focused on postoperative rehabilitation exercises. Although routine rehabilitation training is simple and easy, no nursing interventions have been established for the different stages of functional recovery. However, staged functional training enables targeted rehabilitation training according to the characteristics of different rehabilitation stages and the patient’s rehabilitation progress. This training method divides the rehabilitation process into different stages, and each stage has specific goals and training methods to gradually restore limb function and mobility[12].

In the rehabilitation of patients with ankle fractures, plantar flexion angle, dorsiflexion angle, and AOFAS Ankle-Hindfoot Score are commonly used measures to assess ankle function and rehabilitation progress. Plantar flexion angle is the extent of dorsal flexion of the ankle and reflects the range of motion and flexibility of the ankle joint. During rehabilitation, the progress of patients’ recovery and functional mobility (e.g., ankle stiffness or dysfunction) can be determined by measuring the plantar flexion angle. The dorsiflexion angle is the degree of ankle extension toward the sole of foot. Similarly, the dorsiflexion angle is an indicator of the range of motion and rehabilitation progress of the ankle joint. In patients with ankle fractures, measuring the dorsiflexion angle can help determine ankle flexibility and rehabilitation. The AOFAS Ankle-Hindfoot Score is a standard scoring system for assessing ankle and hindfoot function. The score is a functional assessment of different aspects, such as pain, gait, joint stability, ankle range of motion, balance, and daily living functions[13]. The AOFAS Ankle-Hindfoot Score is a comprehensive assessment of ankle joint and hindfoot function and a means of tracking rehabilitation progress. In this study, after 1 and 2 months of intervention, the plantar flexion angle, dorsiflexion angle, and AOFAS Ankle-Hindfoot scores of subjects after staged functional training following ankle fracture surgery were significantly higher than those before intervention (P < 0.05).

Functional exercise after ankle surgery helps promote blood flow around the ankle joint and accelerate the recovery process. Appropriate exercise can facilitate lymphatic and blood reflux, thereby reducing postoperative swelling and pain. Continuous functional training helps maintain muscle strength around the ankle joint and prevent muscle atrophy caused by postoperative braking. Exercise gradually restores the normal range of motion of the ankle joint and prevents joint dysfunction due to adhesion or stiffness[14]. Patient compliance with functional exercise is influenced by psychological factors. Positive attitude, confidence in rehabilitation, and good self-management can help improve exercise compliance, which in turn, maximizes the recovery of ankle function. Functional exercise compliance has many positive effects on functional recovery. To maximize rehabilitation, patients should faithfully adhere to the physician’s advice and insist on appropriate functional exercise after surgery. Furthermore, medical staff and rehabilitation therapists should also provide sufficient guidance and support to help patients increase their exercise compliance[15].

The mechanism of social support on postoperative ankle function is a complex research field. Social support encompasses the material or emotional support an individual receives from their social network, which can include family, friends, the wider community, or other social institutions. Social support plays an important role in rehabilitation after ankle surgery. First, social support can provide the necessary emotional support for patients. Surgery is a strong psychophysiological stressor, and patients often face emotional problems, such as pain, anxiety, and depression. At this time, the care, understanding, and encouragement provided by families, friends, and medical staff can help patients relieve tension, bolster rehabilitation confidence, and improve treatment compliance[16]. Second, social support can help patients obtain better postoperative and life care, such as assistance in functional exercises and provision of a nutritious diet. The care and help given by family members and friends can help patients recover better. In addition, social support can also include information and knowledge support for patients. Postoperative patients need to understand the different aspects of rehabilitation training and daily rehabilitation nursing to improve self-management and rehabilitation progress. Medical staff and rehabilitation physicians can also provide patients with relevant information to help them better understand and retain rehabilitation knowledge and skills. In conclusion, the impact of social support on postoperative function after ankle surgery is manifold in providing patients with the emotional support, postoperative nursing, and life care, as well as the information and knowledge they might need to achieve optimal recovery. Therefore, in rehabilitation after ankle surgery, the role of social support should be emphasized, and patients should be encouraged to actively seek and utilize social support resources for optimal recovery[17]. At the same time, medical staff and social workers should also evaluate the patient’s social support status and provide necessary support and help if needed.

BK, PGE 2, and 5-HT are bioactive substances with distinct roles in pain transmission and inflammatory response. BrBK is a peptide produced in vascular endothelial cells and has strong physiological activity[18]. The release of BK promotes vasodilation and increased permeability while enhancing pain perception at nerve endings. In tissue damage or inflammation, BK levels are often elevated, which indicates increased pain. PGE2 is a prostaglandin-like substance and an important mediator of inflammatory response. It can increase pain perception by stimulating inflammatory cells to release PGE2 receptors at nerve endings. PGE2 also participates in the inflammatory process, promotes congestion, edema, and the release of inflammatory mediators in local tissues, resulting in aggravated tissue injury and pain. 5-HT is a neurotransmitter that mainly functions in the central nervous system and peripheral tissues. It helps transmit pain signals in peripheral nerve terminals[19]. Furthermore, 5-HT can promote pain symptoms by stimulating 5-HT receptors and increasing neuronal excitability and pain perception. The interactions among BK, PGE2, and 5-HT in pain perception and inflammatory response form a complex regulatory network. However, the reduction of pain symptoms can be effectively mediated through periodic functional training[20].

CONCLUSION

In conclusion, the independent risk factors affecting functional performance after staged functional training following ankle surgery are exercise compliance, social support and pain level. Clinical nursing care after ankle surgery needs to integrate analgesic and health education measures to promote and optimize limb function recovery. To optimize rehabilitation, patients should follow the physician’s advice and insist on appropriate functional exercise after surgery. Furthermore, medical staff and rehabilitation therapists should also provide patients sufficient guidance and support to improve their exercise compliance. Relevant studies that analyzed independent risk factors affecting intervention nursing in ankle function recovery are lacking. Further nursing studies involving larger datasets and multiple centers need to be performed to provide robust data and reference for clinical practice.