Femoral Neck Stress Fracture: Can MRI Grade Help Predict Return-to-Running Time?

Osseous Stress Injuries: Treatment Algorithms and Return to Play

Osseous stress injuries are common in athletes. Specifically, lower extremity injuries are prevalent in running athletes and upper extremity injuries are prevalent in throwing athletes. Such injuries are suspected when there is focal bone tenderness and increased pain with the inciting activity. In elite athletes, osseous stress injuries are a relatively common culprit in lost play time. Thus rapid diagnosis and treatment is imperative to expedite return to play (RTP). The radiologist's role in these cases is not only for diagnosis, but also to grade the injury, which has implications in determining a treatment regimen. The high sensitivity and specificity of magnetic resonance imaging is thus the preferred imaging modality. This article discusses common osseous stress injuries, the imaging findings, and how different treatment regimens affect RTP.

Return to sport following low-risk and high-risk bone stress injuries: a systematic review and meta-analysis

OBJECTIVE

Bone stress injuries (BSIs) are classified in clinical practice as being at low- or high-risk for complication based on the injury location. However, this dichotomous approach has not been sufficiently validated. The purpose of this systematic review was to examine the prognostic role of injury location on return-to-sport (RTS) and treatment complications after BSI of the lower extremity and pelvis.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Web of Science, Cochrane CENTRAL and Google Scholar databases were searched from database inception to December 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Peer-reviewed studies that reported site-specific RTS of BSIs in athletes.

RESULTS

Seventy-six studies reporting on 2974 BSIs were included. Sixteen studies compared multiple injury sites, and most of these studies (n=11) described the anatomical site of injury as being prognostic for RTS or the rate of treatment complication. Pooled data revealed the longest time to RTS for BSIs of the tarsal navicular (127 days; 95% CI 102 to 151 days) and femoral neck (107 days; 95% CI 79 to 135 days) and shortest duration of time for BSIs of the posteromedial tibial shaft (44 days, 95% CI 27 to 61 days) and fibula (56 days; 95% CI 13 to 100 days). Overall, more than 90% of athletes successfully returned to sport. Treatment complication rate was highest in BSIs of the femoral neck, tarsal navicular, anterior tibial shaft and fifth metatarsal; and lowest in the fibula, pubic bone and posteromedial tibial shaft.

CONCLUSION

This systematic review supports that the anatomical site of BSIs influences RTS timelines and the risk of complication. BSIs of the femoral neck, anterior tibial shaft and tarsal navicular are associated with increased rates of complications and more challenging RTS.

PROSPERO REGISTRATION NUMBER

CRD42021232351.

Femoral Neck Stress Fracture of a Male, Healthy Marathon Runner - Case Report and Literature Review

In the present report, a case of a healthy, 38-year-old male recreational marathon runner who presented in the emergency department is discussed. He was diagnosed with a stress fracture of the femoral neck and treated surgically using a dynamic hip screw (DHS). One year after surgery, the patient was able to return to most of his previous sports activities. In the present report, the existing literature on the subject is exhibited and the points of interest in terms of incidence, risk factors, diagnosis, classification, treatment, and long-term outcome are analyzed. We suggest operative treatment of stress fractures of the femoral neck even in cases of complete undisplaced ones. This way, the risk of a displacement is counteracted, and patients can quickly return to daily activities without having to withstand long-term immobilization.

Femoral Neck Stress Fractures: An Updated Review

Femoral neck stress fractures represent a relatively rare spectrum of injuries that most commonly affect military recruits and endurance athletes. If unrecognized and if proper treatment is not initiated, this condition carries potentially devastating consequences. Patients will typically present with an insidious onset, atraumatic hip, and groin pain that is relieved with rest. The condition may be initially misdiagnosed because radiographs are often normal. Magnetic resonance imaging has demonstrated superior specificity, sensitivity, and accuracy compared with other diagnostic modalities in identifying and classifying stress fractures of the femoral neck. Treatment algorithms are based on the MRI fracture morphology and presence of an intra-articular effusion. Nonsurgical management consists of a period of non-weight-bearing followed by gradual return to activity. Surgical management consists of prophylactic fracture fixation with cannulated screws to prevent fracture progression. If left untreated, patients may progress to a complete displaced femoral neck fracture, which can be associated with complications that include nonunion, osteonecrosis of the femoral head, and long-term disability. These poor outcomes emphasize the importance of early diagnosis and treatment of incomplete femoral neck stress fractures.

Femoral Neck Stress Fractures in Athletes and the Military

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Femoral neck stress fractures (FNSFs) are an infrequent condition in athletic and military populations.

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A high index of suspicion with liberal use of magnetic resonance imaging (MRI) is vital for early recognition and treatment initiation.

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An associated hip effusion on MRI is a risk factor for an evolving stress injury and requires close assessment and consideration for repeat MRI.

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Stress reactions and stable, incomplete FNSFs (<50% of femoral neck width) can be treated nonsurgically.

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Surgical intervention is accepted for high-risk, incomplete (≥50% of femoral neck width), and complete FNSFs.

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Overall, there is a paucity of high-quality literature on the rates of return to activity following FNSF.

Does Magnetic Resonance Imaging Grading Correlate With Return to Sports After Bone Stress Injuries? A Systematic Review and Meta-analysis

BACKGROUND

While some studies have failed to reveal any significant relationship between magnetic resonance imaging (MRI) grading and return to sports after bone stress injuries, others have reported either a linear or nonlinear relationship.

PURPOSE

To evaluate the prognostic value of MRI grading for time to return to sports and rate of return to sports after bone stress injuries.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was performed in PubMed, Web of Science, SPORTDiscus, and Google Scholar. Studies reporting return to sports data after bone stress injuries using MRI grading systems were included in this review. The risk of bias was evaluated using the Quality in Prognosis Studies tool. Meta-analyses were performed to summarize the mean time to return to sports. The Pearson correlation was used to determine the relationship between time to return to sports and MRI grade. A meta-analysis of proportions was conducted to determine the percentage of athletes who successfully returned to sports.

RESULTS

A total of 16 studies with 560 bone stress injuries met inclusion criteria. Higher MRI-based grading was associated with an increased time to return to sports (P < .00001). Pooled data revealed that higher MRI-based grading correlated with a longer time to return to sports (r = 0.554; P = .001). Combining all anatomic locations, the mean time to return to sports was 41.7 days (95% CI, 30.6-52.9), 70.1 days (95% CI, 46.9-93.3), 84.3 days (95% CI, 59.6-109.1), and 98.5 days (95% CI, 85.5-112.6) for grade 1, 2, 3, and 4 injuries, respectively. Trabecular-rich sites of injury (eg, pelvis, femoral neck, and calcaneus) took longer to heal than cortical-rich sites of injury (eg, tibia, metatarsal, and other long-bone sites of injury). Overall, more than 90% of all athletes successfully returned to sports.

CONCLUSION

The findings from this systematic review indicate that MRI grading may offer a prognostic value for time to return to sports after the nonsurgical treatment of bone stress injuries. Both MRI grade and location of injury suggest that individually adapted rehabilitation regimens and therapeutic decisions are required to optimize healing and a safe return to sports.

[Femoral neck stress fracture in a young runner - a rare but severe injury]

A 29-year-old athlete suffered from vague hip pain during the preparation for a marathon competition. During the competition, severe pain forced him to drop out after 29 kilometres. He underwent conventional x-rays immediately, which showed a displaced lateral fracture of the femoral neck. The fracture was immediately treated with a dynamic hip screw. A few days later, the patient was discharged. He returned to sport upon completion of treatment. Vague hip pain after exercise may be an indicator for a rare stress fracture of the femoral neck and should be taken into consideration in athletes. Delayed diagnostic investigation and treatment reduce return-to-sport rates and outcomes.

Stress Fractures of the Hip and Pelvis

Stress fractures refer to overuse injuries of bone resulting from repetitive mechanical stress. Stress fractures of the hip and pelvic region, while relatively uncommon, have become increasingly recognized in certain populations, particularly long-distance runners and military recruits. The diagnosis of such injuries can be challenging, often hampered by a nonspecific physical examination and limited sensitivity of plain radiography. Early recognition is important to direct appropriate management, lessen time lost from sport, and avoid potential complications. The present article reviews the epidemiology, diagnosis, and management of bone stress injuries of the hip and pelvis, specifically the sacrum, pubic ramus, and femoral neck.

A Primer on Running for the Orthopaedic Surgeon

Long-distance running has become increasingly popular during the past decades. Many running patients pose questions to their orthopaedic surgeons regarding risks, benefits, and running techniques. This article identifies 11 running-related questions that patients may ask and provides information to help answer those questions. This review discusses data on the health benefits of running, common running injuries, the relationship between running and osteoarthritis, recommendations regarding running after orthopaedic surgery, running shoes, and other questions that may arise when treating the running athlete.

Statistical Analysis of Dependent Observations in the Orthopaedic Sports Literature

Background:

Orthopaedic research may involve multiple observations from the same patient because of bilateral joint involvement, multiple disease sites, or recurrent disease episodes. These situations violate statistical independence and need to be accounted for via appropriate statistical techniques. Failing to account for nonindependence may lead to biased and overly precise effect estimates.

Purpose:

To determine the degree to which orthopaedic sports medicine studies analyze dependent observations and the proportion of these failing to account for nonindependence.

Study Design:

Cross-sectional study.

Methods:

Clinical studies published in The American Journal of Sports Medicine from 2012 to 2017 were reviewed. Studies reporting nonindependent observations because of multiple extremity involvement or multiple disease episodes were identified. Methods to account for nonindependence were recorded. Studies violating the assumption of independence were identified and stratified by study design, level of evidence, body part involved, and inclusion of a statistician coauthor. Univariate logistic regression was used to determine whether these factors were associated with violations of statistical independence.

Results:

After screening 1016 articles, 886 clinical studies were reviewed. A total of 135 (15%) studies analyzed dependent observations, and 111 (82%) of these failed to account for nonindependence. Relative to the knee, studies of the hip (odds ratio [OR], 0.21; P = .02) and the thigh or leg (OR, 0.03; P = .004) were less likely to violate statistical independence. Study design (P = .03) was also associated with violations of statistical independence. Among studies that analyzed dependent observations, the median proportion of dependent observations relative to the total number of observations in each study was 0.07 (interquartile range, 0.04-0.12).

Conclusion:

The analysis of dependent observations is common in the orthopaedic sports literature, but most studies do not adjust for nonindependence in these situations. Investigators should be aware of incorrect inferences arising from nonindependence and how to statistically adjust for dependent data.

A Review and Proposed Rationale for the use of Ultrasonography as a Diagnostic Modality in the Identification of Bone Stress Injuries

Bone stress injuries are common in military personnel and athletes. The delayed diagnosis of a bone stress injury can lead to a more severe injury that requires a longer period of treatment. The early detection of bone stress injuries is a central part of management. Currently, the reference standard for detecting bone stress injuries is magnetic resonance imaging. However, the expanding use of point-of-care ultrasonography (US) may enable the early detection of bone stress injuries in the clinical setting. In this article, we review the US detection of bone stress injuries, as well as discuss the rationale for the use of US in the diagnosis of these injuries.

Femoral Neck Stress Fractures: MRI Risk Factors for Progression

BACKGROUND

Femoral neck stress fractures are overuse injuries with devastating consequences if not diagnosed and treated appropriately. The aim of this study was to retrospectively review femoral neck stress fractures using a magnetic resonance imaging (MRI)-based protocol and to identify imaging risk factors that could predict fracture progression requiring surgical intervention.

METHODS

We identified all femoral neck stress fractures treated at our institution from 2002 to 2015. Inclusion criteria for the study were unilateral pathology involving either an incomplete femoral neck stress fracture with a visualized fracture line or edema without a distinct fracture line. MRI data were evaluated for edema, fracture line percentage, and hip effusion. A surgical procedure was offered to patients with fractures with interval progression on serial MRI after 6 weeks of nonoperative treatment.

RESULTS

We identified 305 patients who met inclusion criteria. Initial MRI showed edema with a fracture line in 54.4% of patients and isolated edema in 45.6% of patients. Interval MRI was performed in 194 patients at a mean time of 6 weeks, and it revealed fracture progression in 13.9% of patients. There were no significant differences in the size of the fracture line on initial MRI between the group who progressed to a surgical procedure and those who resolved with nonoperative treatment (mean [and standard deviation], 24.6% ± 8.1% [95% confidence interval (CI), 21.4% to 27.8%] and 25.5% ± 11.1% [95% CI, 22.9% to 28.1%]; p = 0.287). Of the patients who required a surgical procedure, 85.2% had an effusion on the initial MRI compared with only 26.3% of those who showed interval resolution with nonoperative treatment. Those who had a hip effusion on the initial MRI had 8 times (relative risk, 8.02 [95% CI, 2.99 to 21.5]; p < 0.0001) the risk of fracture progression to surgical fixation compared with those without a hip effusion.

CONCLUSIONS

In patients with a femoral neck stress fracture and fracture line, the presence of a hip effusion on the initial MRI screening is an independent risk factor for fracture progression and early prophylactic surgical intervention should be considered. All patients with isolated edema in the femoral neck without a fracture line on the initial MRI had resolution with nonoperative treatment and did not have fracture progression toward surgical fixation.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Management and treatment of femoral neck stress fractures in recreational runners: a report of four cases and review of the literature

Femoral neck stress fractures (FNSFs) in healthy young subjects are uncommon and most prevalent among long-distance runners and military recruits. Women seem to be at higher risk of developing stress fractures because of possible eating disorders followed by amenorrhea and osteoporosis. This case report describes four young and middle-aged, active female recreational runners who developed stress fractures of the femoral neck. In three of them, with a clinical history of persistent pain in the groin region, which worsened during training, early diagnosis by MRI was considered essential in detecting the fractures. The patients were clinically, metabolically and radiographically evaluated; they were then treated and followed-up at our institution. Only one case was treated conservatively, while the others underwent surgical internal fixation using a screw-plate (DHS®). All of them returned to sport physical activity after a recovery period. Regarding the challenging management of FNSFs, our report highlights the importance of groin pain, especially in athletic females, an early diagnosis by MRI, and a proper classification of these injuries for a correct choice of treatment in order to prevent further dislocation and avoid avascular necrosis of the femoral head. (www.actabiomedica.it)

Management and treatment of femoral neck stress fractures in recreational runners: a report of four cases and review of the literature

Femoral neck stress fractures (FNSFs) in healthy young subjects are uncommon and most prevalent among long-distance runners and military recruits. Women seem to be at higher risk of developing stress fractures because of possible eating disorders followed by amenorrhea and osteoporosis. This case report describes four young and middle-aged, active female recreational runners who developed stress fractures of the femoral neck. In three of them, with a clinical history of persistent pain in the groin region, which worsened during training, early diagnosis by MRI was considered essential in detecting the fractures. The patients were clinically, metabolically and radiographically evaluated; they were then treated and followed-up at our institution. Only one case was treated conservatively, while the others underwent surgical internal fixation using a screw-plate (DHS®). All of them returned to sport physical activity after a recovery period. Regarding the challenging management of FNSFs, our report highlights the importance of groin pain, especially in athletic females, an early diagnosis by MRI, and a proper classification of these injuries for a correct choice of treatment in order to prevent further dislocation and avoid avascular necrosis of the femoral head.

Management and treatment of femoral neck stress fractures in recreational runners: a report of four cases and review of the literature

Femoral neck stress fractures (FNSFs) in healthy young subjects are uncommon and most prevalent among long-distance runners and military recruits. Women seem to be at higher risk of developing stress fractures because of possible eating disorders followed by amenorrhea and osteoporosis. This case report describes four young and middle-aged, active female recreational runners who developed stress fractures of the femoral neck. In three of them, with a clinical history of persistent pain in the groin region, which worsened during training, early diagnosis by MRI was considered essential in detecting the fractures. The patients were clinically, metabolically and radiographically evaluated; they were then treated and followed-up at our institution. Only one case was treated conservatively, while the others underwent surgical internal fixation using a screw-plate (DHS®). All of them returned to sport physical activity after a recovery period. Regarding the challenging management of FNSFs, our report highlights the importance of groin pain, especially in athletic females, an early diagnosis by MRI, and a proper classification of these injuries for a correct choice of treatment in order to prevent further dislocation and avoid avascular necrosis of the femoral head.

Return to sport following stress fractures of the great toe sesamoids: a systematic review

INTRODUCTION

This review aims to provide information on return rates and times to sport following stress fractures of the great toe sesamoids (SFGTSs).

SOURCES OF DATA

A systematic search of CINAHAL, Cochrane, EMBASE, Google Scholar, Medline, PEDro, Scopus, SPORTDiscus and Web of Science was performed using the keywords 'stress', 'fractures', 'great', 'toe', 'sesamoid', 'athletes', 'sports', 'non-operative', 'conservative', 'operative' and 'return to sport'.

AREAS OF AGREEMENT

Fourteen studies were included: three studies reported on the outcome of conservatively-managed SFGTSs; thirteen studies reported on the outcome of surgically-managed SFGTSs. The management principles were to attempt conservative management for 2-6 months using activity modification, analgesia, orthotics and physiotherapy; if symptoms persisted following this, surgical management was to be recommended, either with internal fixation or sesamoidectomy.

AREAS OF CONTROVERSY

The optimal treatment modalities for SFGTSs remain to be defined.

GROWING POINTS

Internal fixation shows the best return to full-level sport rates with low rates of complications.

AREAS TIMELY FOR DEVELOPING RESEARCH

Future prospective studies should aim to establish the optimal treatment modalities for SFGTSs.

Lower limb stress fractures in sport: Optimising their management and outcome

Stress fractures in sport are becoming increasing more common, comprising up to 10% of all of sporting injuries. Around 90% of such injuries are located in the lower limb. This articles aims to define the optimal management of lower limb stress fractures in the athlete, with a view to maximise return rates and minimise return times to sport. Treatment planning of this condition is specific to the location of the injury. However, there remains a clear division of stress fractures by “high” and “low” risk. “Low risk” stress fractures are those with a low probability of fracture propagation, delayed union, or non-union, and so can be managed reliably with rest and exercise limitation. These include stress fractures of the Postero-Medial Tibial Diaphysis, Metatarsal Shafts, Distal Fibula, Medial Femoral Neck, Femoral Shaft and Calcaneus. “High risk” stress fractures, in contrast, have increased rates of fracture propagation, displacement, delayed and non-union, and so require immediate cessation of activity, with orthopaedic referral, to assess the need for surgical intervention. These include stress fractures of the Anterior Tibial Diaphysis, Fifth Metatarsal Base, Medial Malleolus, Lateral Femoral Neck, Tarsal Navicular and Great Toe Sesamoids. In order to establish the optimal methods for managing these injuries, we present and review the current evidence which guides the treatment of stress fractures in athletes. From this, we note an increased role for surgical management of certain high risk stress fractures to improve return times and rates to sport. Following this, key recommendations are provided for the management of the common stress fracture types seen in the athlete. Five case reports are also presented to illustrate the application of sport-focussed lower limb stress fracture treatment in the clinical setting.

Femoral Neck Stress Fractures in Sport: A Current Concepts Review

Femoral neck stress fractures (FNSFs) account for 3% of all sport-related stress fractures. The commonest causative sports are marathon and long-distance running.

The main types of FNSF are compression-sided, tension-sided and displaced. The most common reported symptom is exercise-related groin pain. Radiographs form the first line of investigation, with MRI the second-line investigation.

The management of FNSFs is guided by the location and displacement of the fracture. Delay in diagnosis is common and increases the likelihood of fracture displacement. Sporting outcomes are considerably worse for displaced fractures. Education programmes and treatment protocols can reduce the rates of displaced FNSFs.

This article aims to provide a current concepts review on the topic of FNSFs in sport, assess the current evidence on the epidemiology and pathophysiology of these injuries, detail the current recommendations for their imaging and management, and review the recorded sporting outcomes for FNSFs in the existing literature.

From this study, we conclude that although FNSFs are a rare injury, they should be considered in all athletes presenting with exercise-related hip pain, because delay in diagnosis and subsequent fracture displacement can significantly impair future return to sport. However, when detected early, FNSFs show promising results in terms of return-to-sport rates and times.