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Femoral Neck Stress Fracture
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Contents
Other Names
- Femoral neck stress fractures (FNSF)
Background
- This page describes stress fracture of the neck of the Femur
History
- Initially reported by the German Military as early as 1905[1]
Epidemiology
- Account for around 3% of all stress fractures seen in the athlete[2]
- Account for 4.1% of stress fractures in female athletes, only 1.8% in male athletes
- Represent 50% of all femoral stress fractures[3]
- Age range 16-56, more common in women[4]
Pathophysiology
- General: Stress Fractures (Main)
- Occur as a result of repetitive submaximal mechanical load across the femoral neck
- As with all stress fractures, this occurs when the bone absorption exceeds mechanical repair during remodeling
- Vast majority of cases occur in individuals with normal bone and excessive forces
- Starts with a "crack" but can propagate with inadequate healing time
- Femur can tolerate 3-5 times body weight during exercise
- Compression-type
- Occur due to compressive forces on the inferomedial neck
- Typically remains stable until it reaches 50% of the femoral neck width[5]
- More oblique then tension-type, considered more stable and less likely to displace
- Tension-type
- Occur due to tension forces on the superolateral neck
- Normally counterbalancd by Gluteus Medius, Gluteus Minimus
- However when these muscles become fatigued, tension forces develop on the superior neck
- This creates a fracture line at 90° to the broken cortex
- Results in a transverse fracture which is more unstable and likely to displace
- Early detection is important
- Increased awareness has been shown to improve early detection[6]
Pathoanatomy
- Muscle Insertions on the femoral neck
- Vascular Supply
Risk Factors
- Female Gender
- Mostly attributed to Relative Energy Deficiency In Sport
- Poor baseline physical conditioning[7]
- Decreased Bone Mineral Density[8]
- Sudden increase in training intensity
- Coxa Vera[9]
- Coxa Profunda
- Acetabular Retroversion
- Sports
- Marathon running
- Long-distance running
- Basketball
- Gymnastics
- Ballet dancing
- Military Recruits
Differential Diagnosis
- Fractures And Dislocations
- Arthropathies
- Muscle and Tendon Injuries
- Bursopathies
- Ligament Injuries
- Neuropathies
- Other
- Pediatric Pathology
- Transient Synovitis of the Hip
- Developmental Dysplasia of the Hip (DDH)
- Legg-Calve-Perthes Disease
- Slipped Capital Femoral Epiphysis (SCFE)
- Avulsion Fractures of the Ilium (Iliac Crest, ASIS, AIIS)
- Ischial Tuberostiy Avulsion Fracture
- Avulsion Fractures of the Trochanters (Greater, Lesser)
- Apophysitis of the Ilium (Iliac Crest, ASIS, AIIS)
Clinical Features
- History
- Gradual or insidious onset of poorly localized pain
- Worse with weight bearing or activity, improves with rest
- In one study, 87% of patients endorsed anterior groin pain[10]
- Typically involves a recent increase in training intensity
- Early in disease state, pain only arrives towards the later stages of exercise
- Later in the disease process, the pain arrives early in exercise
- Eventually pain can even occur at night or at rest
- If it goes on long enough, patients may endorse popping or cracking sensation as the fracture starts to displace
- Physical Exam: Physical Exam Hip
- Examination is often non-specific
- Painful at extreme arc of motion of hip, especially with internal rotation
- May be tender on anterior palpation of the hip
- Special Tests
- Fulcrum Test: Arm is placed under affected femur and used as a fulcrum to recreate pain
- Hop Test: Patient jumps up and down on affected limb to recreate pain
Evaluation
Radiographs
- Standard Radiographs Hip
- Views should include AP Pelvis, AP and lateral of hip
- Findings, when present, include:[11]
- Periosteal and endosteal callous formation
- Sclerotic linear region traversing the primary trabeculae of the femoral neck
- Radiolucent fracture line
- Up to 2/3 of patients will have normal radiographs
- 6-8 weeks often required for radiographic changes
- Around half of patients will never have radiographic changes[12]
MRI
- Generally considered second line imaging but is the gold standard for FNSF
- Strongly consider in all athletes with suspected stress fracture and negative XR
- Sensitivity, specificity and accuracy are 100%[13]
- Findings include:
- Diffuse, ill-defined, rounded hypo-intense area (T1-weighted images)
- Equivalent hyper-intense signal (on fat-suppressed T2-weighted images)
- When present, the fracture line is seen as a linear area of hypo-intense signal, extending at right angles from the affected cortex
Bone Scan
- Radionucleotide bone scan largely replaced by MRI
- Consider if MRI unavailable or patient unable to obtain
Laboratory Evaluation
- Typically only indicated if patient has had multiple stress fractures
- See: Stress Fractures - Laboratory Evaluation
Classification
Fullerton & Snowdy
- Type I: fractures occurred on the tension-side of the femoral neck[14]
- "Tension side" on the superolateral neck
- Type II: fractures on the compression-side
- "Compression side" on the inferomedial neck
- Type III: fractures were displaced
Shin & Gillingham
- Subdivides type II into fractures lines to greater or less than 50% of the femoral neck[12]
Management
Prognosis
- Early detection is important[15]
- Nondisplaced fractures are more easily treated with higher success rates, as high as 100%
- Undetected fractures that become displaced have a worse prognosis, success rates as low as 0%
- Displacd FNSF
- 50% of all athletes fail to return to previous sporting levels[18]
- Rates are closer to 60% in those who suffer a displaced fracture
- Prevention
- US Military: Introduction of prompt imaging of all suspected serviceman has lead to a reduction displacd FNSF
- Limit training volume increases to no more than 10% per week
- For beginners, total training volume should not exceed 160 km over a 12 week period
Nonoperative
- Indications
- Incomplete Compression-type (<50% femoral neck width)
- Atypical Tension
Operative
- Indications
- Incomplete Tension-type
- Complete Tension-type
- Complete Compression-type
- Displaced
- Technique
- Dynamic Hip Screw
- Cannulated Hip Screw
Rehab and Return to Play
Rehabilitation
- Post-operative
- Non-weight bearing or toe-touch for 6 weeks
- Followed by partial weight bearing for 6 weeks
- Upper Limb: Unrestricted post-operatively
- Hydrotherapy can start as early as 2 weeks
- Weight bearing should not commence until radiographic and clinical evidence of fracture union
- Graduated return to activity typically begins about week 12
- Physical Therapy: emphasis on hip strength, range of motion
- Gradual increase in running program during which patient can progress if pain free
- Non-operative
- Similar management to operative cases
- Athlete should be limited weight bearing on crutches until pain free, which typically takes 6-8 weeks
- Rehabilitation is similar to surgical where there should be clinical and radiographic evidence of fracture union
- Athlete should be pain free with full activity before return to sport, typically around 12 weeks
Return to Play
- General
- Typical full return to sport occurring around 3-6 months
- Athletes should be followed radiographically for up to 2 years to ensure adequate fixation, lack of pain and absence of AVN
- Running
- Ramey et al: mean time to return to running was 14 weeks in one study[19]
Complications
- Re-fracture
- Fracture propagation and displacement
- Surgical complications
- Avascular Necrosis (24-42%)
- Non-union (16-44%)
- Delayed union (8–50%)
- Malunion (5–33%)
- Failure of fixation (14%)
- Need for rvisional surgery (21–50%)
- Hip Osteoarthritis (68%)
See Also
- Internal
- External
- Sports Medicine Review Hip Pain: https://www.sportsmedreview.com/by-joint/hip/
References
- ↑ Belcher A. Ueber den Einfluss des Parademarches auf dieEntstehung der Fussgeschwulst. Med Klin. 1905;1:305–306.
- ↑ Hulkko A, Orava S. Stress fractures in athletes. Int J Sports Med. 1987;8:221–226.
- ↑ O’Brien J, Taunton J, Larsen J, Forster B B. 31-year-old female runner with 5-week history of hip pain. Br J Sports Med. 2011;45:136–139.
- ↑ Robertson, Greg A., and Alexander M. Wood. "Femoral neck stress fractures in sport: a current concepts review." Sports Medicine International Open 1.02 (2017): E58-E68.
- ↑ Egol K A, Koval K J, Kummer F, Frankel V H.Stress fractures of the femoral neck Clin Orthop Relat Res 1998. doi:http://www.ncbi.nlm.nih.gov/pubmed/955353672–78.
- ↑ Scott S J, Feltwell D N, Knapik J J, Barkley C B, Hauret K G, Bullock S H, Evans R K. A multiple intervention strategy for reducing femoral neck stress injuries and other serious overuse injuries in U.S. Army Basic Combat Training. Mil Med. 2012;177:1081–1089.
- ↑ Kupferer K R, Bush D M, Cornell J E, Lawrence V A, Alexander J L, Ramos R G, Curtis D. Femoral neck stress fracture in Air Force basic trainees. Mil Med. 2014;179:56–61.
- ↑ Pouilles J M, Bernard J, Tremollieres F, Louvet J P, Ribot C. Femoral bone density in young male adults with stress fractures. Bone. 1989;10:105–108.
- ↑ Carpintero P, Leon F, Zafra M, Serrano-Trenas J A, Roman M. Stress fractures of the femoral neck and coxa vara. Arch Orthop Trauma Surg. 2003;123:273–277.
- ↑ Neubauer T, Brand J, Lidder S, Krawany M.Stress fractures of the femoral neck in runners: a review. Res Sports Med 2016. doi:10.1080/15438627.2016.11914891–15.
- ↑ Spitz D J, Newberg A H. Imaging of stress fractures in the athlete. Radiol Clin North Am. 2002;40:313–331.
- ↑ 12.0 12.1 Shin A Y, Gillingham B L. Fatigue fractures of the femoral neck in athletes. J Am Acad Orthop Surg. 1997;5:293–302.
- ↑ Shin A Y, Morin W D, Gorman J D, Jones S B, Lapinsky A S. The superiority of magnetic resonance imaging in differentiating the cause of hip pain in endurance athletes. Am J Sports Med. 1996;24:168–176.
- ↑ Fullerton L R, Jr., Snowdy H A. Femoral neck stress fractures. Am J Sports Med. 1988;16:365–377.
- ↑ Pihlajamaki H K, Ruohola J P, Weckstrom M, Kiuru M J, Visuri T I. Long-term outcome of undisplaced fatigue fractures of the femoral neck in young male adults. J Bone Joint Surg Br. 2006;88:1574–1579.
- ↑ Pihlajamaki H K, Ruohola J P, Kiuru M J, Visuri T I. Displaced femoral neck fatigue fractures in military recruits. J Bone Joint Surg Am. 2006;88:1989–1997.
- ↑ Visuri T, Vara A, Meurman K O. Displaced stress fractures of the femoral neck in young male adults: a report of twelve operative cases. J Trauma. 1988;28:1562–1569.
- ↑ Johansson C, Ekenman I, Tornkvist H, Eriksson E. Stress fractures of the femoral neck in athletes. The consequence of a delay in diagnosis. Am J Sports Med. 1990;18:524–528.
- ↑ Ramey L N, McInnis K C, Palmer W E. Femoral neck stress fracture: can MRI grade help predict return-to-running time? Am J Sports Med. 2016 doi: 10.1177/0363546516648319.