Medial Malleolar Stress Fracture Treatment and Return to Activity: A Systematic Review

Abstract

Background:

Medial malleolar stress fractures (MMSFs) naturally appear to occur primarily in athletes participating in sports requiring prolonged running or repetitive jumping. Nonoperative and operative modalities have been described, yielding a wide range of outcomes and return to activity (RTA) rates.

Hypothesis/purpose:

To systematically review the current literature to identify reports of MMSFs to better understand the current state of treatment, outcomes, and RTA rate.

Methods:

Studies published in PubMed, Embase, and the Cochrane Library reporting on patients sustaining MMSF from inception to October 2024 were identified. Human subjects, articles published in English, and studies reporting treatment (operative vs nonoperative), outcomes, RTA rates, and the incidence of any complications, were included.

Results:

Seventeen studies were identified, consisting of 68 patients, with 74% (n = 50/68) of patients being male. Weighted mean patient age was 26.1 (range, 9-73) years. Overuse injury mechanisms during sporting activities accounted for 94% (n = 64/68) of injuries, with soccer being the most commonly reported athletic activity (n = 18). Initial operative management was reported in 44% (n = 30/68) of patients at a weighted mean of 10.1 weeks from symptom onset, with an additional 14 patients undergoing operative treatment following a weighted mean 16.8-week trial of nonoperative management. Complications following treatment were reported in 4 (n = 4/30) patients treated initially with surgery and 2 (n = 2/38) patients initially treated nonoperatively. A total of 98% (n = 57/58) of patients reported successful return to preinjury activity levels at a weighted mean of 3.4 months.

Conclusion:

Medial malleolar stress fractures are reported to occur primarily in younger, adult patients, commonly as a result of overuse, especially in individuals participating in soccer. Operative management was performed in 65% (n = 44/68) of overall cases with a low rate of complication and a high rate of successful RTA following nonoperative and operative management.

Visual Abstract.

This is a visual representation of the abstract.

Introduction

Lower extremity stress fractures occur in patients engaged in high load-bearing and repetitive activities such as running, military drills, jumping, and aerobic exercise.^{4,7,16,17,22,31} Stress fractures generally result from overuse when osseous microfractures occur at a rate that exceeds the inherent ability of the bone to repair.^7,9,10 The distal one-third of the tibial diaphysis is the most common site for stress fractures to develop in the lower extremity.^10,15,16

Stress fractures of the medial malleolus are reported to typically occur in athletes participating in running and jumping activities, ⁸ accounting for 0.6% to 4.1% of all stress fractures and 10% of stress fractures involving the foot and ankle.^15,16,29 MMSFs often occur secondary to the rapid increase of compressive sheer stresses placed across the distal tibia, as well as abnormal weight transmission and torsional forces placed across the ankle joint.^16,27,29 Symptoms may be insidious and vague, with the primary complaint being localized pain and swelling over the medial ankle and distal tibia.^7,16,29 Both nonoperative and operative management techniques have been reported for the treatment of symptomatic MMSFs. Although studies have reported operative intervention to increase the likelihood of early healing and return to activity (RTA) among athletes,^7,8 other studies have shown that activity modification and rest result in successful healing and symptom resolution. ²²

Optimal treatment for symptomatic MMSFs, as well as indications for operative intervention, and RTA based on management technique, remain largely unknown. The purpose of this investigation was to systematically review the current literature to identify patients with MMSF, evaluating injury etiology and characteristics, as well as any potential differences in outcomes and RTA based on nonoperative vs operative treatment. The authors hypothesized that the majority of MMSFs would be reported in younger patients, participating in sports involving continuous running, with no differences in outcomes or RTA based on definitive management.

Methods

Search Strategy and Eligibility Criteria

A systematic review was conducted according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. ²³ A literature search identifying studies reporting on clinical outcomes and RTA in patients with MMSF was conducted on October 5, 2024. Three authors (N.D.B., S.T., D.C.T.) independently conducted a systematic review of the current literature using PubMed, Cochrane Database for Systematic Review, Cochrane Central Register for Controlled Trials, and Embase databases from inception to October 2024. The search was performed using the following search terms with Boolean operators: “medial malleolus stress fracture,” “medial malleolus,” “medial malleolar,” “outcomes,” “fatigue fracture,” and “stress fracture.”

Inclusion criteria consisted of studies written in English or with English-language translation reporting isolated MMSFs with reported injury etiology (acute traumatic vs chronic overuse), symptom characteristics (eg, medial malleolar pain, tenderness, and swelling), diagnostic findings, management (nonoperative vs operative), surgical techniques, postoperative complications, and any patient-reported outcomes, including duration of rehabilitation and RTA. Exclusion criteria consisted of cadaveric, biomechanical, and animal studies, previous meta-analyses and systematic reviews, review articles, editorial commentaries, patients with medial malleolar injuries not characterized as “stress-fractures,” and any patient with MMSFs with any associated injury to the leg, ankle, or foot).

Title and abstract screening were independently performed by 3 of the authors (N.D.B., S.T., D.C.T.), followed by a full-text review performed by 2 authors (N.D.B., D.C.T.) to determine if studies met inclusion or exclusion criteria (Figure 1). A fourth, independent author (D.M.K.) was assigned to consult if any disagreements were encountered among the 3 authors, of which none were encountered. References from the included studies were reviewed to ensure no additional studies meeting inclusion criteria had been overlooked, of which no additional studies were identified.

Figure 1.

Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) diagram.

Data Extraction

For studies undergoing full-text review, the following study characteristics from each article were extracted and entered into a Microsoft Excel, version 16.84 (Microsoft Corp, Redmond, WA) spreadsheet: study title, year published, first author, level of evidence, patient demographics (mean age at the time of presentation, sex), mechanism or etiology of injury, onset of symptoms, symptom characteristics, diagnosis (imaging type), management type (nonoperative vs operative) and technique, incidence of any postoperative complications (eg, reoperation, refracture, and postoperative stiffness), postoperative imaging and the incidence of bony union vs nonunion, patient-reported outcomes, duration of rehabilitation, RTA rate, and final follow-up time.

Study Quality Assessment

To minimize bias, a methodologic quality assessment was performed by 3 independent authors (N.D.B., S.T., D.C.T.) using the Joanna Briggs Institute (JBI) critical appraisal tool for case series (Appendix A) and JBI critical appraisal tool for case reports (Appendix B). A fourth author (D.M.K.) was consulted if any disagreements were encountered, of which no disagreements were reported. The JBI critical appraisal tools consist of 10 questions for case series and 8 questions for case reports, with each question scored as follows: Y, yes; N, no; U, unclear; and NA, not applicable. The total percentage of “yes” responses was recorded for each study and each question, with the highest achievable score being 100% (range, 0%-100%).^2,19

Data Analysis

Patient demographics and study characteristics were compiled and analyzed using Microsoft Excel, version 16.84 (Microsoft Corp). Variables such as patient age and mean follow-up were calculated and displayed as a weighted mean while assessing management characteristics, complication rates, and RTA.

Results

The initial literature search identified 226 articles (Figure 1). Following the removal of 9 duplicates, 217 articles underwent title and abstract screening. A total of 47 articles were then selected to undergo full-text review to assess for inclusion eligibility. After a full-text review, 17 studies published from 1988 to 2023 met the inclusion and exclusion criteria. Six studies were of Level IV^{8,12,16,20,22,25} evidence and 11 were of Level V^{1,3,6,11,13,14,17,21,24,26,27} evidence. Methodologic quality assessments of the 17 included studies using the JBI critical appraisal tools are shown in Appendixes A and B. The mean “yes” score for case series was 62% (range, 50%-90%), whereas the mean “yes” score for case reports was 88% (range, 50%-100%).

Study and Patient Characteristics

A total of 68 patients with reported MMSFs were identified from the 17 studies included for analysis (Table 1). The weighted mean patient age was 26.1 (range, 9-73) years, whereas 74% of patients (n = 50/68) were male. Weighted mean final follow-up time was 26.3 (range, 0.7-132) months, whereas the final follow-up time was not reported for 2 patients in a single study. ²⁵

Table 1.

Overview of Included Studies.

Study	No. of Patients	Mean Age	% of Male Patients	Injury Etiology (Sport)	Nonsurgical Treatment	Surgical Treatment
Ariyoshi et al. (1997) 1	1	14	100	Overuse (volleyball)	NWB + crutches, 8 wk + 12 additional wk	−
Barati et al. (2023) 3	1	60	0	Overuse (walking)	NWB + short leg cast, 6 wk	ORIF a
Hitchen and Lyons (1996) 6	1	9	0	Overuse (roller skating)	Activity modification	-
Jowett (2008) 8	4	23.8	75	Overuse (sprinting, n = 1; Australian rules football n = 2; cricket n = 1)	Corticosteroid injection (n = 1)	Arthroscopy + percutaneous fixation (n = 4) a
Kanto et al. (2014) 11	1	18	100	Overuse (basketball)	-	Percutaneous cannulated screw fixation
Kimura et al. (2023) 12	5	57.2	0	Overuse (n = 2); no clear cause (n = 3)	NWB + short leg cast, 4 wk (n = 2); activity modification, 8-12 wk (n = 3)	-
Kor et al. (2003) 13	3	19.5	100	Overuse (basketball, n = 2; football, n = 1); overuse followed by trauma (basketball, n = 1)	NWB + short leg cast, 3 wk + removable boot, 3 wk (n = 1); removable boot + activity modification (n = 1)	Percutaneous cannulated screw fixation (n = 1)
Kumar et al. (2002) 14	1	18	100	-	Conservative treatment, 8 wk	-
Lempainen et al. (2012) 16	10	23	60	Overuse (track and field, n = 6; long-distance running, n = 2; soccer, n = 1; biathlon, n = 1)	Limited WB with crutches, 6 wk + activity modification, 3-4 months (n = 5); unspecified (n = 2)	Compression osteosynthesis (n = 10) a
Menge and Looney (2015) 17	1	14	100	Overuse (basketball)	NWB + short leg cast, 6 wk; walking boot, 2 wk	Percutaneous fixation a
Nguyen et al. (2019) 20	16	23.6	100	Overuse (soccer, n = 16)	-	ORIF, ankle arthroscopy for ankle debridement (n = 16)
Okada et al. (1995) 21	2	35	50	Overuse (walking, n = 1; kendo fencing, n = 1)	Tape fixation, 4 wk (n = 1); short leg cast, 2 wk + tape fixation, 6 wk (n = 1)	-
Orava et al. (1995) 22	8	28	88	Overuse (track and field, n = 2; sprinting, n = 3; middistance running, n = 1; recreational, n = 1); overuse followed by trauma (track and field, n = 1)	Activity modification, 2-3 mo (n = 5); unspecified (n = 2)	Compression osteosynthesis (n = 1); oblique drilling (n = 2) a
Reider et al. (1993) 24	1	21	100	Overuse prior to and following trauma (football)	Aspiration of ankle, corticosteroid injection	ORIF with debridement a
Schils et al. (1992) 25	7	23.6	71	Overuse (running, n = 3; football, n = 1; soccer, n = 1; multisport, n = 1; nonathlete, n = 1)	Walking boot, 6-8 wk (n = 4)	ORIF (n = 3)
Shabat et al. (2002) 26	1	15	0	Overuse followed by trauma (gymnastics)	Elastic bandage + activity modification, 6 wk	ORIF a
Shelbourne et al. (1988) 27	5	19.2	80	Overuse (basketball, n = 1; cross-country running, n = 1); overuse followed by trauma (basketball, n = 3)	Walking boot ± activity modification, 6 wk (n = 2); activity modification, 3 wk (n = 1)	ORIF (n = 2)

Abbreviations: NR, not reported; NWB, nonweightbearing; ORIF, open reduction internal fixation; WB, weightbearing.

^aIncludes patient(s) who were treated operatively following the initial round of nonoperative treatment.

Injury Etiology

Overuse injuries during sporting activities accounted for 94% (n = 64/68) of MMSFs, whereas an acute, traumatic mechanism comprised 7 (n = 7/68) reported injuries (Table 1). No definitive etiology was reported in 4 patients (n = 4/68).^12,14 The most commonly reported sporting activities were soccer^16,20,25 (n = 18), followed by running and sprinting^{8,16,22,24,27} (n = 11), and track and field (ie, jumps and hurdles)^16,22 (n = 9). Additional athletic activities included basketball,^11,13,17,27 American football,^25-27 and prolonged periods of walking and hiking.^3,21,22

Injury Presentation

The timing from symptom onset to presentation was reported in 68% (n = 46/68) of patients in 15 studies,^{1,3,6,8,11-14,17,20-22,24,26,27} with a weighted mean of 3.5 (range, 0-24) months. Pain localized to the medial malleolus was the presenting complaint in 100% of patients (n = 68/68), with tenderness to palpation^{1,3,6,11,13,14,16,17,22,24-27} reported in 57% (n = 39/68) and swelling reported in 18 patients (n = 18/68).^{1,11,13,16,22,24,27} Additional symptoms included pain and tenderness over the tibial plafond,^13,16,22,25 pain and decreased range of motion with ankle dorsiflexion,^1,11,24,26 ankle effusion, ²⁷ and a painful mass over the medial malleolus. ²⁴ In studies reporting associated conditions, 13 patients (n = 13/60) were diagnosed with ankle varus malalignment^12,20 during their initial presentation.

Diagnosis and Treatment

Plain radiography was performed in 100% (n = 68/68) of cases, with computed tomography (CT)^{8,11,20-22,25,26} used in 46% (n = 31/68), magnetic resonance imaging (MRI)^{1,3,8,11-13,16,17,21,22} in 31% (n = 21/68), and radionuclide bone scan^{1,13,21,22,25-27} in 28% (n = 19/68). When reported, plain radiography revealed 46% (n = 24/52) of fractures on initial evaluation,^{1,6,8,12-14,21,22,25-27} whereas 54% (n = 28/52) required secondary imaging to confirm a diagnosis.^{3,8,11-13,16,17,21,22,24,25,27} Fracture orientation was reported in 13 studies (59% of patients, n = 40/68). A vertically oriented fracture from the tibial plafond and medial malleolar junction was reported in 93% (n = 37/40) of patients,^{1,3,11,12,17,20,21,24-27} whereas 3 (n = 3/40) patients sustained an obliquely oriented fracture from the junction through the medial malleolus.^14,16,25 Osteolytic bone lesions were reported on plain radiographs ²⁵ in 3 patients and CT^21,25 in 3 patients.

Nonoperative management was initially attempted in 56% (n = 38/68) of cases, consisting of a combination of activity modification or avoidance (n = 19),^{1,6,12,13,22,26,27} bracing/walking boot (n = 9),^13,17,25,27 crutches (n = 6),^1,16 or nonweightbearing (NWB) in a short leg cast (n = 5)^3,12,13,17 (Table 1). When recommended, NWB was undertaken from between 6 weeks ¹⁶ and 8 weeks (with an additional 12 weeks due to unresolved MRI findings). ¹ The duration of ankle brace or walking boot use was provided in 4 studies and ranged from 2 to 8 weeks.^13,17,25,27 Activity modification/avoidance, consisting of sport cessation or avoidance of rigorous training, ranged from 5 weeks to 4 months as a primary treatment method^12,22,27 or following an initial period of bracing.^13,16,26,27 Meanwhile, corticosteroid injections^8,24 were reported in 2 patients, whereas 1 patient underwent aspiration ²⁴ of the ankle.

Operative management was performed in a total of 65% (n = 44/68) of patients at a weighted mean of 18.5 weeks from symptom onset. Surgery was the initial treatment^{8,11,13,16,20,22,25,27} in 44% (n = 30/68) of patients at a weighted mean of 10.1 weeks from symptom onset. Operative management following a weighted mean 16.8-week trial of failed nonoperative treatment^{3,8,16,17,22,24,26} was reported in 14 (n = 14/68) patients at 43.8 weeks from symptom onset. Operative treatment included open reduction and internal fixation (ORIF)^{3,16,20,22,24-27} (n = 35) consisting of compression screws ± plating; percutaneous screw fixation^8,11,13,17 (n = 7); or drilling ²² to promote fracture healing of the medial malleolus (n = 2). Concomitant arthroscopic debridement of the ankle was performed in 70% (n = 21/30) of patients treated initially with surgery.^8,20,24 Surgical treatment with corresponding fracture orientation was reported in 13 studies (52% of patients, n = 35/68).^{1,3,11,12,14,16,17,20,21,24-27} Vertically directed fractures were treated with ORIF^3,20,24-27 or percutaneous fixation^11,17 in 73% (n = 24/33) of cases, whereas 1 (n = 1/2) oblique fracture underwent surgical management with ORIF. ¹⁶

Posttreatment Complications

Complications following treatment were reported in 6 patients (n = 6/68), including 4 undergoing surgical management^8,20,25 and 2 treated definitively with nonoperative management (Table 2).^12,25 Complications following nonoperative treatment included persistent pain beyond 1 year postinjury requiring ankle arthrodesis, ¹² as well as a complete vertical fracture of the medial malleolus in the setting of a previously overlooked lytic lesion while running 2 weeks after initial evaluation. ²⁵ This patient was treated with a cast for 8 weeks and returned to full activity 5 months later. ²⁵

Table 2.

Outcomes Following Medial Malleolus Stress Fracture Management.

	Study	No. of Patients	Complications/ Adverse Events	% RTA	% Bony Union/ Confirmed Healing	Mean Follow-up (mo)
Nonoperative treatment	Ariyoshi et al. (1997) 1	1	NR	100	100	12
	Barati et al. (2023) 3	1	Treatment failure (n = 1) a	–	–	–
	Hitchen and Lyons (1996) 6	1	None	100	100	4
	Jowett et al. (2008) 8	1	Treatment failure (n = 1) a	–	–	–
	Kimura et al. (2023) 12	5	Persistence of pain requiring arthroscopic ankle arthrodesis (n = 1)	NR	100	41.4
	Kor et al. (2003) 13	2	None	100	100	5.1
	Kumar et al. (2002) 14	1	None	NR	100	1.9
	Lempainen et al. (2012) 16	7	Treatment failure (n = 7) a	–	–	–
	Menge and Looney (2015) 17	1	Treatment failure (n = 1) a	–	–	–
	Okada et al. (1995) 21	2	NR	100	100	6
	Orava et al. (1995) 22	7	Treatment failure (n = 2) a	100	100	7.6
	Reider et al. (1993) 24	1	Vertical fracture nonunion (n = 1) a	–	–	–
	Schils et al. (1992) 25	4	Complete vertical fracture (n = 1)	100	100	2.3
	Shabat et al. (2002) 26	1	Nondisplaced MM fracture (n = 1) a	–	–	–
	Shelbourne et al. (1988) 27	3	NR	100	100	1.2
Operative Treatment	Barati et al. (2023) 3	1	None	100	100	6
	Jowett et al. (2008) 8	4	Postoperative stiffness (n = 2)	100	100	13.5
	Kanto et al. (2014) 11	1	None	100	100	6
	Kor et al. (2003) 13	1	None	100	100	60
	Lempainen et al. (2012) 16	10	None	90	100	62
	Menge and Looney (2015) 17	1	None	100	100	3
	Nguyen et al. (2019) 20	16	Fifth metatarsal base fracture (n = 1)	100	100	38.2
	Orava et al. (1995) 22	3	NR	100	100	11.3
	Reider et al. (1993) 24	1	None	NR	100	7
	Schils et al. (1992) 25	3	Complete MM vertical fracture (n = 1)	NR	NR	8
	Shabat et al. (2002) 26	1	None	100	100	24
	Shelbourne et al. (1988) 27	2	None	100	100	1.2

Abbreviations: MM, medial malleolus; NR, not reported; RTA, return to activity.

^aPatient(s) were treated operatively following an initial round of nonoperative treatment.

Postoperative complications included ankle stiffness (n = 2), both reported to resolve with hydrodilatation and physiotherapy. ⁸ One patient with reported varus malalignment discontinued orthotic use at 3 months following surgery and sustained a subsequent fifth metatarsal base fracture at 26 months postoperatively. ²⁰ Another patient sustained a vertical fracture of the medial malleolus after running at 7 months following ORIF, necessitating revision ORIF. ²⁵

Posttreatment Outcomes

Return to activity rate was reported in 85% (n = 58/68) of patients from 14 studies. Successful RTA was reported in 98% (n = 39/40) of patients undergoing operative management at a weighted mean of 3.5 (range, 0.5-16.0) months, with 100% (n = 39/39) reporting a return to their prior level of activity. One patient was unable to continue athletics due to a fracture-dislocation sustained before presentation, which resulted in cartilage damage, synovitis, and long-term ankle stiffness precluding successful RTA. ¹⁶ In patients treated definitively with nonoperative management, 18 patients (n = 18/18) reported successful RTA at a weighted mean of 2.8 (range, 3.0-6.0) months, with all 18 patients (n = 18/18) reporting a return to their prior level of competition.

Fracture healing after treatment was evaluated in 97% of patients (n = 66/68) in 17 studies. Complete healing following nonoperative management was confirmed radiographically in 16 patients (n = 16/16). Bony union following operative management was confirmed radiographically in 25 patients (100%, n = 25/25). Clinical evidence of bony union at the time of final follow-up was determined by the lack of tenderness over the medial malleolus and the ability to resume activities without discomfort ⁸ in 24 patients treated nonoperatively and in 42 patients treated operatively.

Discussion

The principal findings from this investigation were of the 68 patients identified from 17 studies, MMSF was reported to occur at a mean age of 26.1 years, with 74% of patients (n = 50/68) being male. Overuse injury secondary to athletic activities was reported in 94% of injuries (n = 64/68), occurring primarily during soccer. Injuries were initially managed surgically in 44% of patients (n = 30/68), primarily consisting of ORIF and percutaneous fixation. A total of 37% of patients (n = 14/38) required operative intervention after a failed trial of nonoperative management. Successful RTA was reported in 98% of patients (n = 39/40) undergoing surgery and all patients treated nonoperatively. Bony healing was reported in 100% of patients (n = 41/41) evaluated radiographically following treatment.

MMSF is distinct from medial malleolar fracture in several key aspects. Although isolated medial malleolar fractures may occur, complex injuries involving bimalleolar or trimalleolar fracture patterns are more common. ⁵ These injuries generally develop from an acute twisting mechanism resulting in immediate pain and inability to bear weight, leading to a characteristically evident fracture line on plain radiography. Isolated medial malleolar fractures are managed nonoperatively with high levels of success, whereas displaced and unstable fractures are typically managed with surgery. ⁵ Conversely, MMSF is a rare injury that generally results from overuse and repetitive microtrauma in running and jumping athletes, leading to a gradual onset of pain that worsens with activity. Although a fracture line may be visible in some cases, initial radiographs are often normal, necessitating advanced imaging to confirm the diagnosis. Similarly, high healing rates are achieved with conservative management, whereas surgery is typically indicated in cases of nonoperative treatment failure, radiographically evident and displaced fractures, and competitive athletes.

Overuse mechanisms involving repetitive loading to the ankle joint in patients participating in activities requiring running were reported in 94% of patients (n = 64/68). Acute traumatic injuries, including planting or landing firmly with the ankle in a dorsiflexed, abducted, or inverted position during running or jumping activities, accounted for only 7 injuries.^13,24,26,27 It is theorized that MMSFs arise from forefoot pronation during repetitive heel strike and dorsiflexion, resulting in navicular abduction, internal rotation of the talus, and force transmission to the anteromedial aspect of the tibial plafond and medial malleolus.^27,29,30 Microtrauma occurring at the junction of the medial malleolus and tibial plafond results from overuse and repetitive cyclic stress, with fracture propagation vertically through the tibial metaphysis, resulting in a stress fracture once a critical threshold is reached. ²⁷ Conceivably a 1-time maximal load through this same mechanism through an already fatigued ankle during athletic competition likely contributes to traumatic injury and the reports of an acute etiology. Although patients presenting with MMSFs may report an acute incident resulting in pain, MMSF is more likely related to overuse, especially in patients participating in soccer and sprinting-related activities. ³⁰

Radiographically, up to 70% of initial radiographs have been reported to appear normal during early symptom onset.^20,29 In as little as 2 to 4 weeks following symptom onset, fissuring at the junction of the medial malleolus and tibial plafond may be observed^21,27,29 (Figure 2A and 2B). When visible, fracture propagation is frequently vertical in orientation but may arch obliquely from the junction to the tibial metaphysis. ²⁷ Although initial radiographs may not reveal evidence of bony abnormalities, advanced imaging, primarily MRI and CT, is often necessary in patients with continued discomfort after a period of conservative management.^29,30 Studies have reported that CT yields greater sensitivity in the early clinical phase, with MRI providing nearly 100% specificity with precise anatomical resolution of the stress fracture and surrounding soft tissue structures.^8,20 Specifically, MMSF appears on MRI as a low-intensity vertical line projecting from the anteromedial tibial plafond on T1 imaging with a low-intensity band surrounded by areas of high-intensity hemorrhage or edema on T2 imaging.^15-17,29 Meanwhile, CT provides superior resolution of bony anatomy and is generally used for surgical planning purposes.^{8,15,20,22,25,26,32} CT may also detect well-circumscribed lytic lesions near the stress fracture, thought to be early osseous resorption resulting from bony microtrauma^21,25,29 (Figure 2C).

Figure 2.

(A) Initial anteroposterior ankle radiograph of a patient with no prior history of trauma and insidious onset of medial ankle pain following a period of increased walking activity. Taken approximately 3 days after the onset of symptoms, it reveals an indistinct vertical fracture line and 5 mm lucency at the junction of the tibial plafond and medial malleolus. (B) Initial lateral foot radiograph. (C) The initial coronal computed tomography (CT) image reveals a vertical medial malleolar stress fracture (MMSF) with an associated 5-mm subcortical lytic lesion. (D) Weightbearing anteroposterior radiograph taken approximately 14 months from initial presentation reveals healing MMSF.

Nonoperative management was performed in 56% (n = 38/68) of patients with MMSF, whereas 44% (n = 30/68) underwent initial operative management, with 14 patients eventually undergoing surgery after a trial of nonoperative management. Patients with radiographically occult MMSFs are generally treated with an initial trial of nonoperative management if clinical discomfort is the predominant complaint with no visible fracture line on radiographs.^28-30 Activity modification in combination with weightbearing restriction using a walking boot or cast represents the mainstay of nonoperative treatment. A gradual return to activity as determined by patient comfort is then initiated as tolerated. For athletes wishing to maintain physical conditioning during recovery, training activities should be with the expectation of strict pain avoidance. ²⁹ Initial surgical management is typically indicated for patients with a radiographically visible fracture line,^7,29,30 and patients undergo similar surgical treatment rates for vertical and oblique fractures. Surgery has been advocated for in-season athletes wishing to return to sports in a shortened time frame.^{7,26,27,29,30} However, RTA was quicker in athletes treated nonoperatively (mean, 2.8 months) vs those undergoing initial surgical management (mean, 3.5 months). Furthermore, displaced fractures or fractures with evidence of nonunion warrant operative intervention with the use of autologous bone graft to ensure successful healing.^22,28-30 Further studies are warranted to determine criteria for failure of nonoperative management, as well as both mid- and long-term outcomes and RTA rates in patients with MMSF based on treatment.

Return to activity was reported in 98% (n = 39/40) of patients treated operatively (mean, 3.5 months) compared to all (n = 18/18) patients undergoing nonoperative management (mean, 2.8 months). Early case series, limited because of patient sample size, have reported that operative management aids in returning athletes to competition quicker; however, no high-quality, randomized study evaluating comparison treatment groups has been performed.^26-28 Moreover, longer healing times and delayed RTA are not unexpected following fracture fixation because of the indications for surgery (ie, presence of prolonged symptom duration despite initial nonoperative management and presence of a visible fracture line on radiographs), as well as the inherent healing necessary following fixation with restoration of lower extremity muscle strength and endurance during rehabilitation. Additional studies examining predictors for successful RTA based on sport, age, sex, and symptom duration are needed to better understand treatment prognosis and RTA timing in patients with MMSF.

Our study aimed to provide insight into clinical and/or radiographic factors that may potentially serve as indicators for operative vs nonoperative treatment. Although limited by sample size, this review offers a few key takeaways worth noting. Patients treated with operative vs nonoperative management achieved equivalent rates of healing (100%), whereas patients treated nonoperatively reported a slightly higher RTA in less time. All patients reported pain over the medial malleolus, with fewer patients experiencing more severe symptoms (eg, swelling, limited dorsiflexion, and a painful bone mass) during or following activity. Furthermore, the majority of injuries resulted from overuse characterized by a gradual onset of pain, with a smaller subset of patients reporting an acute event (eg, a sudden “pop,” severe pain while planting). Cases involving the sudden symptom onset and/or more severe clinical symptoms were more often managed nonoperatively than those in which progressive pain with activity was the primary symptom. Radiographically, the majority of fractures were observed to have a vertical orientation and were managed surgically more often than nonoperatively. Finally, opportunities for future research include a closer look into the metabolic aspects of MMSFs. Although the majority of studies in this review did not discuss bone mineral density (BMD), vitamin D levels, or hormonal balance, these physiological factors are known to play important roles in bone metabolism, with suboptimal levels leading to stress fracture formation and propagation. ¹⁸ Particularly in the case of female athletes, a thorough analysis of BMD, menstrual function, and energy levels (the female athlete “triad”) may provide further insight into risk factors for MMSF and offer key strategies to enhance treatment and prevention.

Limitations

This study is not without limitations. Because of the small sample size, secondary to the strict inclusion and exclusion criteria used, no meaningful statistical analyses were performed analyzing differences in outcomes and RTA based on management technique, as the authors sought to avoid the pooling of data. Moreover, the included studies were limited primarily to case series and case reports with short follow-up, emphasizing the need for high-level evidence in evaluating outcomes at mid- and long-term follow-up in patients undergoing operative vs nonoperative management. Furthermore, the limited sample size further prohibited the authors from identifying any variables based on patient or injury characteristics that may predict the need for initial operative intervention.

Conclusion

Medial malleolar stress fractures are reported to occur primarily in younger, adult patients, commonly as a result of overuse, especially in individuals participating in soccer. Operative management was performed in 65% of overall cases (n = 44/68) with a low rate of complication and a high rate of successful RTA following nonoperative and operative management.

Appendix A.

Joanna Briggs Institute (JBI) Critical Appraisal Tool for Case Series.

Study	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9	Q10	Total Percentage
Jowett et al 2008 8	Y	Y	Y	Y	Y	Y	Y	Y	U	Y	90
Kimura et al 2023 12	Y	Y	Y	N	N	Y	U	Y	U	N	50
Lempainen et al 2012 16	Y	Y	Y	Y	Y	U	N	Y	N	N	60
Nguyen et al 2019 20	U	Y	Y	U	U	Y	Y	Y	N	Y	60
Orava et al 1995 22	N	Y	Y	Y	N	Y	Y	N	N	N	50
Schils et al 1992 25	Y	Y	Y	N	N	Y	Y	Y	N	N	60
Total percentage	67	100	100	50	33	83	67	83	0	33	62

Abbreviations: Q, question; Y, yes; N, no; U, unclear; NA, not applicable.

Q1: Were there clear criteria for inclusion in the case series?

Q2: Was the condition measured in a standard, reliable way for all participants included in the case series?

Q3: Were valid methods used for identification of the condition for all participants included in the case series?

Q4: Did the case series have consecutive inclusion of participants?

Q5: Did the case series have complete inclusion of participants?

Q6: Was there clear reporting of the demographics of the participants included in the study?

Q7: Was there clear reporting of clinical information of the participants?

Q8: Were the outcomes or follow-up results of cases clearly reported?

Q9: Was there clear reporting of the presenting sites’/clinics’ demographic information?

Q10: Was statistical analysis appropriate?

Appendix B.

Joanna Briggs Institute (JBI) Critical Appraisal Tool for Case Reports.

Study	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Total Percentage
Ariyoshi et al 1997 1	Y	Y	Y	Y	Y	y	Y	U	88
Barati et al 2023 3	Y	Y	Y	Y	Y	Y	N	Y	88
Hitchen and Lyons 1996 6	Y	Y	Y	Y	Y	Y	N	U	75
Kanto et al 2014 11	U	Y	Y	Y	Y	Y	Y	Y	88
Kor et al 2003 13	U	Y	Y	Y	Y	Y	Y	Y	88
Kumar 2002 14	Y	Y	Y	Y	N	U	N	U	50
Menge and Looney 2015 17	Y	Y	Y	Y	Y	Y	Y	Y	100
Okada et al 1995 21	Y	Y	Y	Y	Y	Y	N	Y	88
Reider et al 1993 24	Y	Y	Y	Y	Y	Y	Y	Y	100
Shabat 2002 26	Y	Y	Y	Y	Y	Y	Y	Y	100
Shelbourne et al 1988 27	Y	Y	Y	Y	Y	Y	Y	Y	100
Total percentage	90	100	100	100	90	90	60	70	88

Abbreviations: Q, question; Y, yes; N, no; U, unclear; NA, not applicable.

Q1: Were patient’s demographic characteristics clearly described?

Q2: Was the patient’s history clearly described and presented as a timeline?

Q3: Was the current clinical condition of the patient on presentation clearly described?

Q4: Were diagnostic tests or assessment methods and the results clearly described?

Q5: Was the intervention(s) or treatment procedure(s) clearly described?

Q6: Was the postintervention clinical condition clearly described?

Q7: Were adverse events (harms) or unanticipated events identified and described?

Q8: Does the case report provide takeaway lessons?