Short-term Outcomes and Quality of Life Following Surgical Treatment of Bimalleolar Ankle Fractures

Abstract

Background:

Bimalleolar ankle fractures, particularly those resulting from supination–external rotation (SER) mechanisms, are common injuries. This study evaluates the short-term clinical outcomes and quality of life following surgical treatment of these fractures.

Matеrials and Methods:

This prospective cohort study was conducted at two trauma centers in Isfahan, Iran. A total of 34 adults, with SER-type bimalleolar ankle fractures, underwent open reduction and internal fixation. Additionally, a matched control group comprising 34 healthy individuals was included in the study. Functional outcomes were evaluated using the Foot and Ankle Outcome Score (FAOS) and the Short Form-36 (SF-36) in the control group, as well as at three and six months post-surgery for the patient group.

Results:

The study included 24 males (70.6%) and 10 females (29.4%) in the case group, with a mean age of 32.8 years (SD ± 9.7) and a mean BMI of 26.01 kg/m² (SD ± 1.91). Significant improvements were observed in the patient group from three to six months post-surgery across multiple FAOS and SF-36 domains. FAOS pain scores increased from 67.8 ± 7.5 to 83.9 ± 8.3 (P < 0.001), and activities of daily living improved from 75.3 ± 8.0 to 88.7 ± 8.5 (P < 0.001), approaching control levels. SF-36 physical functioning scores rose from 63.5 ± 8.2 to 81.3 ± 7.9 (P < 0.001). However, domains, like symptoms, sports/recreation, social functioning, and role-emotional, remained lower than controls at six months (P > 0.05).

Conclusions:

Surgical treatment of bimalleolar ankle fractures leads to significant short-term functional improvements, with a low complication rate. While promising, continued rehabilitation beyond six months may be necessary for complete functional restoration.

INTRODUCTION

Ankle fractures are among the most prevalent injuries treated in orthopedic practice, constituting approximately 9% of all fractures in adults.[1,2,3] Bimalleolar fractures, which involve both the lateral and medial malleoli, are particularly significant due to their impact on ankle stability and function.[4] The supination–external rotation (SER) mechanism, as classified by the Lauge-Hansen system, is the most common cause of these fractures.[5] Such injuries often result from low-energy trauma, such as twisting accidents, but can lead to substantial morbidity if not appropriately managed.[6,7]

Open reduction and internal fixation (ORIF) is the standard surgical treatment for displaced bimalleolar ankle fractures to restore anatomical alignment and joint congruity.[7,8] While ORIF has generally shown favorable outcomes, the recovery of full function can vary widely among patients.[9,10] Factors influencing this variability include the specific fracture pattern, the surgical technique employed, rehabilitation protocols, and patient-related factors, such as age and comorbidities.[11]

Despite the frequency of SER-type bimalleolar fractures, there is limited research focusing specifically on their short-term functional outcomes following ORIF.[12] Most existing studies assessed heterogeneous groups of ankle fractures or did not use comprehensive patient-reported outcome measures.[1] The Foot and Ankle Outcome Score (FAOS) and the Short Form-36 (SF-36) are validated instruments that provide detailed insights into patients’ functional status and quality of life, but are underutilized in this context.[13,14]

Understanding the short-term recovery trajectory of patients with SER-type bimalleolar fractures is essential for optimizing the surgical and rehabilitation strategies. It also aids in setting realistic expectations for patients regarding their recovery process. Therefore, this multicenter prospective cohort study aimed to evaluate the short-term clinical outcomes of patients who underwent ORIF for SER-type bimalleolar ankle fractures. By employing standardized surgical techniques, rehabilitation protocols, and validated outcome measures, we seek to provide robust data that can inform clinical practice and enhance patient care.

MATERIALS AND METHODS

Study design and setting

This multicenter prospective cohort study aimed to evaluate the short-term clinical outcomes following surgical treatment of supination–external rotation-type bimalleolar ankle fractures, classified according to the Lauge-Hansen system. This research was conducted from April 2020 to February 2022 at Kashani and Al-Zahra Hospitals, the primary trauma referral centers in Isfahan Province, Iran.

Participants

The study population comprised adults, aged 18–55 years, who sustained supination–external rotation type bimalleolar ankle fractures and subsequently underwent open reduction and internal fixation (ORIF). Patients with other types of ankle fractures were excluded from the study. Additional exclusion criteria included polytrauma, open fractures, preexisting ankle pathology, inflammatory arthritis, peripheral neuropathy, and cognitive impairment that could hinder informed consent or the completion of questionnaires. A control group of healthy volunteers, matched to the patient group by age, sex, and body mass index (BMI), was also included. The control participants had no history of ankle injuries or surgery.

Surgical Technique

All surgical interventions were performed by two experienced orthopedic surgeons (M.T. and H.R.) at each center to ensure consistency in the surgical technique. The patients received either general or spinal anesthesia, as determined by the anesthesiologist, based on clinical status and patient preference. Prophylactic antibiotics were administered 30 min prior to incision to minimize the risk of infection. The patients were positioned supine with a bump under the ipsilateral hip to facilitate surgical access. A tourniquet was applied to the thigh and inflated after limb exsanguination.

A direct lateral approach was used for the malleolus. The fibular fracture was anatomically reduced and stabilized by using a one-third tubular plate.[15] The medial malleolus was approached through a medial incision, and after achieving appropriate reduction, it was fixed using either two 4.0 mm partially threaded cancellous screws. Intraoperative fluoroscopy was used to confirm the anatomical reduction and proper implant placement. The integrity of the syndesmosis was assessed intraoperatively using the hook and external rotation stress tests. If syndesmotic instability was detected, fixation was performed using one or two 3.5 mm cortical screws traversing three cortices [Figure 1].[16,17]

Figure 1.

Postoperative anteroposterior (a) and lateral (b) radiographs following open reduction and internal fixation (ORIF) of a bimalleolar ankle fracture with syndesmotic fixation. The lateral malleolus was stabilized using a one-third tubular plate, with syndesmotic stability achieved through two trans-syndesmotic screws placed through the plate. The medial malleolus was fixed using two screws

Rehabilitation protocol

A standardized postoperative rehabilitation protocol was implemented to ensure uniformity and optimize patient recovery.[11,18] Initially, the patients were immobilized in a short leg splint for the first two weeks and were instructed to maintain a non-weight-bearing status. At the two-week follow-up, sutures were removed, and the patients transitioned to a removable walking boot, continuing non-weight-bearing for six weeks post-surgery. Thereafter, the patients commenced partial weight-bearing as tolerated and initiated a physical therapy regimen emphasizing ankle range of motion, strengthening, and proprioceptive exercises. Full weight-bearing was generally permitted between 8 and 10 weeks, contingent upon clinical and radiographic evidence of fracture healing.[19,20,21] The rehabilitation program was meticulously structured to progress based on individual milestones, such as wound healing, radiographic signs of fracture union, and functional recovery.

Data collection and outcome measures

Baseline demographic data, including age, sex, and BMI index, were collected. Functional outcomes were assessed using the Foot and Ankle Outcome Score (FAOS) and the Short Form-36 (SF-36) at baseline (control group) and at three and six months post-surgery. The SF-36 is a comprehensive 36-item survey that assesses overall health and quality of life across eight subscales: physical functioning, role limitations due to physical health, bodily pain, general health, vitality, social functioning, role limitations due to emotional problems, and mental health. The FAOS is specifically designed to evaluate foot and ankle health across five subscales: pain, symptoms (encompassing swelling and range of motion), activities of daily living, sports and recreation function, and quality of life related to foot and ankle function. For both the SF-36 and FAOS, each subscale yielded a score ranging from 0 to 100, with higher scores reflecting better health outcomes and fewer symptoms.[14,22,23]

Postsurgical complications were systematically recorded and monitored throughout the study period, including any adverse events related to the surgical procedure or recovery process. To minimize potential bias in outcome assessment, the evaluators responsible for collecting postoperative data, including FAOS and SF-36 scores, were independent of the surgical team and unaware of specific surgical details or patient group allocations. While this study was not a randomized controlled trial, the assessment process was effectively blinded owing to the independence of the evaluators, which helped reduce bias in reporting functional outcomes.

Sample size calculation

The sample size determination was based on specific statistical parameters. A 95% confidence level was utilized, represented by Z₁= 1.96, and an 80% statistical power was set, represented by Z₂= 0.84. The variable S represents an estimate of the variability in the standard deviation of the FAOS and SF-36 questionnaire scores across groups. The parameter d represents the minimum detectable difference in mean scores between the groups, set as 0.7S, which was considered a clinically meaningful difference. Based on these parameters, a minimum of 32 participants per group was required, using the following formula:

The study employed a consecutive sampling method, recruiting all eligible patients who met the inclusion criteria during the study period. This approach aimed to minimize selection bias and ensure that the sample was representative of the target population, thus enhancing the reliability and generalizability of the study findings.

Statistical analysis

Data analysis was performed using SPSS version 25.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were used to summarize the demographic and baseline characteristics. Independent t-tests were used to compare continuous variables (age and BMI) between the case and control groups, while Chi-square tests were used to compare categorical variables (gender). The normality of FAOS and SF-36 scores was assessed using the Shapiro–Wilk test, confirming that the data followed a normal distribution. Independent t-tests were used to compare the patient and control groups at each time point, while paired t-tests were used to analyze within-group changes from three to six months. A P value less than 0.05 was considered statistically significant for all analyses.

RESULTS

Demographic characteristics

A total of 68 participants were included in the study, with 34 participants in each group. The case group included 24 males (70.6%) and 10 females (29.4%), while the control group included 23 males (67.6%) and 11 females (32.4%). The average age of the case group was 32.8 ± 9.7 years, compared to 31.6 ± 7.8 years in the control group. The average BMI was 26.01 ± 1.91 kg/m² for the case group and 25.9 ± 2.2 kg/m² for the control group. An independent t-test for continuous variables (age and BMI) and Chi-square test for categorical variables (sex) showed no statistically significant differences between the groups (P > 0.05), confirming their comparability at baseline [Table 1].

Table 1.

Baseline characteristics of the study population

Variables		Case group (n=34)		Control group (n=34)		P
Age (years) (mean±SD)		32.8±9.7		31.6±7.8		0.56
BMI (kg/m²) (mean±SD)		26.01±1.91		25.9±2.2		0.82
Gender (female/male) (%)		29.4%/70.6%		32.4%/67.6%		0.54

Independent t-tests were used to compare age and BMI between groups, and a Chi-square test was used for gender distribution

Functional outcomes

SF-36 and FAOS scores were evaluated at three and six months post-intervention in the case group and compared with those in the control group. Significant improvements were observed in several SF-36 domains in the case group from three to six months [Table 2]. Physical functioning increased from 63.5 ± 8.2 to 81.3 ± 7.9 (P < 0.001), and role physical improved from 70.2 ± 9.4 to 82.5 ± 8.5 (P < 0.001). Bodily pain scores rose from 67.4 ± 8.0 to 84.7 ± 7.2 (P < 0.001). These enhancements indicate substantial functional recovery, with six-month scores approaching the control group levels (physical functioning: P =0.046; role physical: P =0.039; bodily pain: P =0.042).

Table 2.

SF-36 scores for patients and controls

SF-36 Domain		Control group (mean±SD)		Three months (mean±SD)		Six months (mean±SD)		P (three to six months)		P (six months vs. control)
Physical functioning		88.7±6.4		63.5±8.2		81.3±7.9		< 0.001		0.046
Role physical		87.2±7.1		70.2±9.4		82.5±8.5		< 0.001		0.039
Bodily pain		89.6±6.2		67.4±8.0		84.7±7.2		< 0.001		0.042
General health		88.9±5.8		69.1±6.7		84.3±5.9		0.002		0.063
Vitality		90.3±5.5		68.7±6.9		86.1±6.4		< 0.001		0.023
Social functioning		89.5±5.6		72.9±7.3		85.0±6.0		< 0.001		0.056
Mental health		88.3±5.4		74.8±6.6		85.0±6.0		0.001		0.060
Role emotional		87.3±5.4		65.7±6.9		82.0±6.0		< 0.001		0.080

Paired t-tests were used for within-group comparisons (three to six months post-surgery), and independent t-tests were used for between-group comparisons at six months. P<0.05 indicate statistical significance

Significant gains were also observed in vitality (68.7 ± 6.9 to 86.1 ± 6.4; P < 0.001), social functioning (72.9 ± 7.3 to 85.0 ± 6.0; P < 0.001), and role emotional (65.7 ± 6.9 to 82.0 ± 6.0; P < 0.001), reflecting enhanced energy levels, social interactions, and emotional well-being. However, when compared to the control group, social functioning (P = 0.056), role-emotional (P = 0.080), general health (P = 0.063), and mental health (P = 0.060) did not reach statistical significance, despite positive trends.

The FAOS scores showed significant improvements in multiple subscales within the case group from three to six months [Table 3]. Pain scores increased from 67.8 ± 7.5 to 83.9 ± 8.3 (P < 0.001), approaching the control group’s mean of 89.2 ± 7.1 (P = 0.044). Activities of daily living improved from 75.3 ± 8.0 to 88.7 ± 8.5 (P < 0.001), closely matching the control mean (P = 0.029). Quality of life scores increased from 73.1 ± 8.1 to 85.2 ± 9.2 (P < 0.001), nearing control levels (P = 0.055).

Table 3.

FAOS scores for patients and controls

FAOS Subscale		Control group (mean±SD)		Three months (mean±SD)		Six months (mean±SD)		P (three to six months)		P (six months vs. control)
Pain		89.2±7.1		67.8±7.5		83.9±8.3		< 0.001		0.044
Symptoms		87.0±8.2		66.7±6.9		77.4±7.7		< 0.001		0.077
Activities of daily living		93.5±8.1		75.3±8.0		88.7±8.5		< 0.001		0.029
Sports/recreation		85.8±9.5		62.4±8.5		70.5±9.0		0.002		0.073
Quality of life		90.1±9.4		73.1±8.1		85.2±9.2		0.002		0.055

Paired t-tests were used for within-group comparisons (three to six months post-surgery), and independent t-tests were used for between-group comparisons at six months. P<0.05 indicate statistical significance

Although the symptoms subscale improved from 66.7 ± 6.9 to 77.4 ± 7.7 (P < 0.001) and sports/recreation increased from 62.4 ± 8.5 to 75.0 ± 9.0 (P = 0.002), these did not achieve statistical significance compared to the control group at six months (symptoms: P =0.077; sports/recreation: P =0.073).

Complications

Postsurgical complications were documented within the case group, with three participants experiencing complications. These complications included two superficial surgical site infections and one case of restricted ankle range of motion; however, these findings did not reach statistical significance (P > 0.05), indicating a minimal impact on overall outcomes. Complications were effectively managed using conservative treatment. Notably, no major complications or revisions were necessitated, and all patients achieved.

DISCUSSION

This study aimed to evaluate the short-term clinical outcomes of open reduction and internal fixation (ORIF) in patients with supination–external rotation (SER) type bimalleolar ankle fractures. Functional recovery was assessed using the Foot and Ankle Outcome Score (FAOS) and the Short Form-36 (SF-36) at three and six months post-surgery. The results demonstrated significant improvements across multiple domains of both FAOS and SF-36 from three to six months, with several subscales approaching the scores of the healthy control group. Additionally, the incidence of postsurgical complications was minimal, underscoring the efficacy and safety of the ORIF procedure in this patient population.

The substantial enhancements observed in the FAOS and SF-36 scores are consistent with prior studies that emphasize the effectiveness of ORIF in managing bimalleolar ankle fractures. For example, Dwivedi et al.[9] reported that 86.2% of patients achieved excellent-to-good functional outcomes following ORIF, which aligns with the high FAOS and SF-36 scores observed in our study. Similarly, Segal’s cross-sectional observational study highlighted that the severity of ankle fractures correlates with functional limitations, which is consistent with our findings where significant recovery was noted within six months post-surgery.[22]

However, certain SF-36 domains, such as social functioning, role-emotional, general health, and mental health, did not achieve statistical significance compared to the control group at six months. This may be attributable to the residual psychosocial factors associated with recovery from significant musculoskeletal injuries.[24,25] Emotional and social well-being often requires extended periods to fully recover, as patients may experience anxiety, depression, or alterations in social dynamics that are not immediately mitigated by physical healing.[26,27,28] Future studies with longer follow-up periods could provide more comprehensive insights into the long-term psychosocial outcomes of patients undergoing surgical treatment for bimalleolar ankle fractures.

The FAOS scores further underscored the functional improvements achieved post-surgery, particularly in pain management and activities of daily living, which nearly matched the control group levels by the six-month follow-up. This suggests that surgical intervention effectively addresses immediate anatomical and biomechanical deficits, enabling a substantial return to routine daily activities.[18] However, while the symptoms and sports/recreation subscales showed improvement, they did not reach statistical significance compared to the controls, underscoring the challenges in achieving full functional restoration, particularly in activities requiring higher physical performance.

The persistent difference at the six-month mark suggests that complete recovery might extend beyond this timeframe. This is consistent with findings from long-term follow-up studies, such as those by Beckenkamp et al.,[29] who observed ongoing functional improvements up to two years post-injury. As noted by Del Buono et al.,[30] returning to sports following ankle fracture surgery can require up to 51 weeks of structured rehabilitation, and outcomes are significantly influenced by the quality and consistency of the postoperative protocols. These findings emphasize that high-demand activities may necessitate an extended, rigorous rehabilitation to overcome subtle residual deficits in ankle stability and strength, ultimately supporting optimal recovery.

The surgical technique employed in this study, involving ORIF with careful attention to syndesmotic stability, likely contributed to the favorable outcomes observed. This approach aligns with the current best practices in ankle fracture management, as evidenced in recent studies.[4,7] The use of intraoperative fluoroscopy to confirm anatomical reduction and appropriate implant placement, along with standardized postoperative protocols, was integral in minimizing complications and facilitating early rehabilitation.[5,10] The minimal incidence of postsurgical complications, including two cases of superficial surgical site infections and one instance of restricted ankle range of motion, was effectively managed with conservative treatment. The absence of major complications or the need for revision surgery reinforces the procedural safety of ORIF when performed by experienced surgeons under standardized protocols. These findings are consistent with Ahn et al.’s comparison of locking and non-locking plates for distal fibular fractures, which reported low complication rates.[15] The postoperative management protocol utilized in this study included an initial period of four weeks of immobilization, followed by gradual progression to weight-bearing.[19,20,21] This strategy balances the need to protect the surgical repair with the benefits of early mobilization, an approach supported by recent evidence indicating that early mobilization and weight-bearing can enhance functional outcomes without increasing the risk of complications.[19,21]

Clinically, the substantial functional recovery observed suggests that patients with SER-type bimalleolar ankle fractures can anticipate considerable improvements within six months post-surgery when managed with ORIF and a well-structured rehabilitation protocol.

This information is invaluable for clinicians in setting realistic expectations for patients and in planning postoperative care. Moreover, the study underscores the necessity for comprehensive rehabilitation strategies that address not only physical recovery, but also psychological and social aspects to facilitate a holistic return to pre-injury status.

Despite its strengths, including its prospective design and use of validated outcome measures, this study has several limitations. The six-month follow-up period, although informative for short-term outcomes, may not capture the full extent of recovery. Future studies with longer follow-up periods are necessary to assess long-term functional outcomes and potential complications, such as post-traumatic arthritis. Additionally, although the sample size was adequate based on power calculations, a larger cohort would allow for more robust subgroup analyses, potentially identifying the factors that influence recovery trajectories. Future research should consider variables, such as age, comorbidities, and fracture severity, to predict the outcomes.

Furthermore, this study focused exclusively on SER-type bimalleolar fractures, limiting the generalizability of our findings to other ankle fracture patterns. While independent evaluators assessed postoperative outcomes, full blinding was not possible because of the study design. This may introduce some degree of bias, although the use of nonsurgical team members as evaluators helps mitigate this risk. Future studies may benefit from employing double-blind designs to minimize potential biases. Comparative studies examining outcomes across different fracture types and surgical techniques would also provide valuable insights for optimizing treatment strategies. Finally, while this study utilized well-validated patient-reported outcome measures, incorporating objective functional assessments in future research could offer a more comprehensive evaluation of recovery.

CONCLUSION

This study demonstrated that ORIF for SER-type bimalleolar ankle fractures leads to significant short-term functional improvements with a low complication rate. These findings highlight the critical importance of a standardized rehabilitation protocol in facilitating recovery and confirming the utility of the FAOS and SF-36 as reliable outcome measures. However, persistent limitations in symptoms, sports and recreational activities, social functioning, and role-emotional domains suggest that recovery may extend beyond the short term and may require ongoing rehabilitation and potentially more refined surgical techniques to achieve optimal outcomes. This research contributes to the growing evidence supporting ORIF as an effective treatment while identifying areas for further investigation to enhance patient outcomes.

Ethics approval and consent to participate

The study protocol was approved by the Institutional Review Board and Ethics Committee of the Isfahan University of Medical Sciences (IR.MUI.MED. REC.1400.794). Informed consent was obtained from all the participants prior to their inclusion in the study.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.