Orthopedics

The Great Plateau

Authors: Drs. Paul Cohen and Shihab Ali

Case 1:

A healthy 21-year-old female presents to the ED following a motor vehicle crash. She was the restrained passenger in a head-on collision at approximately 30 mph. Her only complaint is left knee pain. On exam, her left knee is tender over the anterior aspect with moderate swelling and ecchymosis. Her ligamentous exam is limited by pain, but there is no gross laxity.  Neurovascular exam is normal, and the remainder of her trauma survey is unremarkable. Plain films are obtained:  

What are the pertinent radiographic findings? 

Figure        SEQ Figure \* ARABIC     1: Illustrative image courtesy of Dr. Mark Holland. (Radiopaedia.org, rID: 19162)

Figure 1: Illustrative image courtesy of Dr. Mark Holland. (Radiopaedia.org, rID: 19162)

Answer:

Lipohemarthrosis is a layering of fat and blood that is indicative of an intra-articular fracture.  Blood and fat from bone marrow escape into the joint space and layer on a horizontal cross-table view because they are different densities. Close inspection also reveals a subtle depression of the lateral tibial condyle consistent with a tibial plateau fracture.    

Figure        SEQ Figure \* ARABIC     2: Radiographs demonstrating lipohemarthrosis (lateral view) and depressed lateral tibial plateau fracture (AP view).

Figure 2: Radiographs demonstrating lipohemarthrosis (lateral view) and depressed lateral tibial plateau fracture (AP view).

Case Outcome:

The diagnosis of a minimally depressed lateral tibial plateau fracture (type III) was made. The patient was evaluated by orthopedics in the ED and discharged home in a knee immobilizer with orthopedic follow-up in 2 days.

Case 2:

An active, independent 72-year-old female presents with left leg pain after a mechanical fall at home. She fell down multiple stairs onto a wooden floor. Her exam is notable for swelling and tenderness of the left knee with a normal neurovascular exam. An AP radiograph of the knee is shown below.

Figure 3. Illustrative image (Gentili A, Tibial Plateau Fracture Imaging, Emedicine)

Figure 3. Illustrative image (Gentili A, Tibial Plateau Fracture Imaging, Emedicine)

What is the diagnosis? How should this injury be managed?

Answer:

A minimally displaced lateral split tibial plateau fracture is depicted on radiographs. This injury is classified as a Schatzker type I fracture and is amenable to nonoperative treatment.

Case Outcome:

Orthopedic surgery was consulted. The patient was placed in a knee immobilizer and admitted. Given the minimal displacement of the fracture, she was managed nonoperatively. No weight-bearing was recommended and she was discharged to a skilled nursing facility with orthopedic follow-up in one week.

Overview of Tibial Plateau Fractures:

Epidemiology:

  • Most common mechanism = axial loading
  • Bimodal distribution:

o   Young adults → high-energy trauma (MVC, fall from height)

o   Elderly → low-energy compression force to osteoporotic bone

  • Majority involve lateral tibial plateau

Associated Injuries:

  • Popliteal artery injury (artery is tethered both proximally and distally at the knee) → any intra-articular disruption can cause vascular injury
  • Displacement of the lateral tibial condyle can cause peroneal nerve injury → assess for foot drop!
  • Concomitant soft tissue injuries are common (e.g., ligaments, meniscus)

o   Ligamentous injury occurs in up to 66% of patients → accurate exam limited on initial presentation due to pain, so follow-up examinations are essential

  • High risk for compartment syndrome!

Diagnostic Imaging:

  • AP and lateral radiographs for initial imaging

o   Lipohemarthrosis suggests occult fracture in the appropriate clinical setting

  • CT is useful for:

o   Diagnosing occult fracture not evident on plain radiographs

o   Improved characterization of fractures

o   Identification of articular depression which may alter management in up to 25% of cases

o   Operative planning

  • MRI shows concomitant soft tissue injury but is rarely indicated in the ED

Classification:

Figure 4: Schatzker Classification of Tibial Plateau Fractures. (Image from Zeltser et al, Classifications in Brief: Schatzker classification of tibial plateau fractures, Clinical Orthopedics and Related Research, 2013 Feb)

Figure 4: Schatzker Classification of Tibial Plateau Fractures. (Image from Zeltser et al, Classifications in Brief: Schatzker classification of tibial plateau fractures, Clinical Orthopedics and Related Research, 2013 Feb)

Management Considerations:

  • Ice and elevate!
  • Schatzker IV injuries are associated with high risk of popliteal injury → consider ABIs and/or vascular imaging (i.e. CTA)
  • Nonoperative management with a hinged knee brace and protected weight bearing is indicated for:

o   Minimally displaced split or depressed fractures

o   Nonambulatory patients

  • Surgical management is common for tibial plateau fractures, especially:

o   Segment depression > 5mm

o   Condylar widening > 6mm

o   Schatzker type ≥ IV

  • Orthopedic consultation is recommended
Figure 5: Algorithm for ED management and disposition. (Karadesh M, Tibial Plateau Fractures, Orthobullets)

Figure 5: Algorithm for ED management and disposition. (Karadesh M, Tibial Plateau Fractures, Orthobullets)

Take Home Points:

  • Tibial plateau fractures are often complex injuries with associated ligament and meniscal disruption
  • Clinical suspicion for occult tibial plateau fracture (i.e., mechanism, age, effusion) warrants CT imaging in the ED
  • Maintain vigilance for neurovascular injury and recognize risk for compartment syndrome
  • Patients with minimally displaced split or depressed fractures can often be discharged in a knee immobilizer as long with close orthopedic follow up assuming adherence to strict non-weight-bearing and adequate pain control
  • More complex fractures often require admission for operative management
  • Consult orthopedics

Faculty Reviewer: Jeffrey P. Feden, M.D.

References:

1. Chan PS, et al. Impact of CT scan on treatment plan and fracture classification of tibial plateau fractures. J Orthop Trauma 1997;11:484–489.

2. Egol KA, Tejwani NC, Capla EL, Wolinsky PL, Koval KJ. Staged management of high-energy proximal tibia fractures (OTA types 41): the results of a prospective, standardized protocol. J Orthop Trauma 2005;19:448–455.

3. Schatzker J, McBroom R, Bruce D. The tibial plateau fracture: the Toronto experience 1968-1975. Clinical Orthop Relat Res 1979;138:84-104.

4. Gentili, Amilcare. Tibial Plateau Fracture Imaging. Emedicine [Internet]. Available from: http://emedicine.medscape.com/article/396920-overview. Accessed 23 March 2017.

5. Karadsheh M.  Tibial Plateau Fractures.  Orthobullets [Internet].  Available from: http://www.orthobullets.com/trauma/1044/tibial-plateau-fractures.  Accessed 20 April 2017.

6. Pallin, Daniel J.  Tibial Plateau Fractures, Knee and Lower Leg, Chapter 57.  Rosen’s Emergency Medicine, 8th ed.  Philadelphia: Elsevier, 2014.  698-722 p.

7. Thomas Ch, Athanasiov A, Wullschleger M, Schuetz M. Current concepts in tibial plateau fractures. Acta Chir Orthop Traumatol Cech. 2009;76(5):363-73.

8. Tscherne H, Lobenhoffer P. Tibial plateau fractures. Management and expected results. Clin Orthop Relat Res 1993;292:87-100.

 

Approach to the Pediatric Limp

Case:

A 4 year old otherwise healthy boy presents to the ED with left leg pain and limp with decreased ability to bear weight. The symptoms started yesterday after watching a movie, with moderate improvement after Motrin. Mom denies any trauma or fall. Notably, he has been afebrile, but has had a mild coryzal illness over the past 3-5 days.

On presentation to the ED, his vital signs are recorded as: T 36.9 C, pulse 120, BP 100/60, RR 22, SpO2 100%. He is alert, active, and non-toxic in appearance. He is lying on the bed, with his hip flexed, abducted, and in external rotation. There is no overlying erythema of the hip, knee, or ankle. The left hip has mild restriction in abduction in comparison the right hip. With the left leg fully extended, the patient exhibits no involuntary muscle guarding or obvious discomfort with log-rolling of the left lower extremity. He additionally has a nontender lumbar spine and ipsilateral knee, ankle, and tibia/fibula. The patient is able to bear weight, but has an antalgic gait without exhibiting toe walking or circumduction. Plain radiographs of the pelvis and left hip are obtained which reveal medial joint space widening in comparison to the right hip.

What is the most likely cause of his symptoms?

A.   Toddler’s fracture

B.   Septic arthritis

C.   Transient synovitis

D.   Osteomyelitis

E.   Limb length discrepancy

C: Transient synovitis

Background:

Limp accounts for approximately 4/1000 visits to the Emergency Department, with the location of the pain not always reflecting the location of pathology. Problems in the hip can cause knee pain, and similarly, back problems can refer pain to the lateral thigh or posterior leg.

Differential:

Minor trauma is the most common etiology for a limp, with the median age being 4 years, boys outnumbering girls 2:1, and localization typically to the hip. In those that deny history of trauma, the most common diagnosis is transient synovitis, with 77% having a benign cause without requiring surgical intervention or hospital admission.

PEM Playbook has a great mnemonic: STOP LIMPING

S: Septic arthritis (hip>knee)

T: Toddler’s fracture (1-3 years, minor fall with rotational component)

O: Osteomyelitis (2% of those children presenting with limp)

P: Perthes disease (Legg-Calve-Perthes disease, an idiopathic AVN, affecting children 3-12 years old)

L: Limb length discrepancy

I: Inflammatory (transient synovitis, 3-6 years of age after viral illness)

M: Malignancy

P: Pyomyositis (possible viral cause such as influenza, often with tender calves)

I: Iliopsoas abscess

N: Neurologic (stroke, will often have underlying pathology such as cardiac lesion, sickle cell disease, metabolic history; ataxia can present with a reported ‘limp’)

G: Gastrointestinal (appendicitis), genitourinary (testicular/ovarian torsion)

One of the ‘can’t-misses’ is the pediatric septic hip, which typically results from three sources: hematogenous spread, local spread (osteomyelitis), direct inoculation (trauma, surgery). S. aureus is the most common causative organism in all age groups, with Salmonella considered in sick cell disease patients, and N. gonorrhea in sexually active patients.

Evaluation:

CBC, ESR, CRP are indicated in an acutely limping child in whom infectious etiology is a possible cause. Also consider Lyme if living in an endemic area, and there are no abnormalities on plain radiography.

If suspicion for septic arthritis remains high despite negative plain radiographs, recent studies have show utility in ultrasonography to identify effusions. Unfortunately, US cannot differentiate between septic arthritis and toxic/transient synovitis as both will result in effusions and mild widening of the joint space, as seen in this patient. MRI is favored over radionuclide scanning for osteomyelitis, stress fracture, and early avascular necrosis. MRI is also indicated if spinal pathology is suggested. Computed tomography (CT) is rarely useful in the patient with a limp, but can diagnose appendicitis, deep soft tissue infections of the paraspinal and retroperitoneal regions.

American College of Radiology Appropriateness Criteria

Traumatic – XR

Atraumatic, no signs of infection – XR, if negative then US hip

Atraumatic, signs of infection – US hip, if negative consider XR, if negative and still concerned for septic arthritis consider MRI

Disposition:

Patients with high concern for bone or joint infection require orthopedic consultation, emergent bone or joint aspiration, and early initiation of antibiotic therapy. A child with an oncologic process requires admission for staging workup and initiation of treatment. Most children have a benign etiology. Afebrile children with normal radiographs are suitable to followup with PCP, after discharging with NSAIDs. Ambulatory febrile children, with normal radiography and blood studies can also be followed up as an outpatient. If the patient remains febrile and unable to bear weight, have a low threshold to pursue joint aspiration. If the patient is afebrile, but unable to bear weight despite an adequate dose of analgesia, consider observation for MRI if early osteomyelitis, AVN, or spinal pathology is high on your differential.

Any unstable patient requires treatment as presumed sepsis, with fluid resuscitation and initiation of empiric antibiotics, orthopedics consultation for source control, and consideration of ultrasonography or MRI. One antibiotic regimen includes nafcillin 50 mg/kg, ceftriaxone 50 mg/kg; consider adding vancomycin 10 mg/kg if concerned for MRSA or sepsis.

Kocher’s criteria:

Our orthopedic colleagues utilize the Kocher criteria to determine the probability of whether the pediatric patient has a septic arthritis. The four elements include:

  • Erythrocyte sedimentation rate >40
  • WBC >12
  • Non-weight bearing on the affected joint
  • Fever >38.5 C

If elements are present, the probability of septic arthritis was determined to be:

  • 0/4 = 0%
  • 1/4 = 3%
  • 2/4 = 40%
  • 3/4 = 93%
  • 4/4 = >99%

HIGH pretest probability? – Kocher's criteria predictive value is HIGH

LOW pretest probability? – Kocher's criteria predictive value is LOW

A 2011 ACEP News Release confirms that Kocher’s criteria remains the best method for EM providers to differentiate transient synovitis and septic arthritis. If 2 or more criteria are present, talk with your orthopedic colleagues.

Takeaways:

  • Assume that any child with a fever who presents with refusal to walk has septic arthritis or osteomyelitis until proven otherwise. Transient synovitis is a diagnosis of exclusion!
  • 2 or more Kocher criteria should prompt orthopedic consultation for consideration of joint aspiration.
  • Discuss care with PCP for prompt re-evaluation if patient’s ED examination is improving and they are stable for discharge.

References:

Brady M. The child with a limp. J Pediatr Health Care. 1993:7:226.

Singer J. The cause of gait disturbance in 425 pediatric patients. Pediatr Emerg Care. 1985;1:7.

Chung S. Identifying the cause of acute limp in childhood. Clin Pediatr. 1974;13:769.

Fischer S, Beattie T. The limping child: epidemiology, assessment and outcome. J Bone Joint Surg Br. 1999;81:1029.

Pediatric Emergency Playbook. Please, just stop limping! Available at: http://pemplaybook.org/podcast/please-just-stop-limping/. Accessed April 3, 2017.

Leet A, Skaggs D. Evaluation of the acutely limping child. Am Fam Physician. 2000;61:1011.

Huttenlocher A, Newman T. Evaluation of the erythrocyte sedimentation rate in children presenting with limp, fever, or abdominal pain. Clin Pediatr. 1997;36:339.

American College of Radiology ACR Appropriateness Criteria. Limping child – ages 0-5 years. Available at: https://acsearch.acr.org/docs/69361/Narrative/. Accessed April 3, 2017.

ACEP News. Kocher criteria still the best way to ID septic arthritis in children. Available at: https://www.acep.org/MobileArticle.aspx?id=82236&coll_id=716&parentid=740. Accessed April 3, 2017.

Kocher M, Zurakoski D, Kasser J. Differentiating between septic arthritis and transient synovitis of the hip in children: an evidence-based clinical prediction algorithm. J Bone Joint Surg Am. 1999;81(12):1662.

Kocher M, Mandiga R, Zurakoski D, et al. Validation of a clinical prediction rule for the differentiation between septic arthritis and transient synovitis of the hip in children. J Bone Joint Surg Am. 2004;86:1629.

An Overlooked Cause of Hip Pain

Case:

A 28-year-old male presents to the Emergency Department with acute-on-chronic hip pain.  His past medical history includes sickle cell disease and poorly controlled asthma for which he takes daily prednisone. He has been ambulating with a cane for one year due to his hip pain. He immigrated one week ago from Puerto Rico and reports worsening hip pain since arriving.  He denies fevers, chills, weakness, or numbness.  No tobacco, alcohol, or drug use.  His radiographs are shown below.  Can you make the diagnosis? Click the answer box below. 

Figure 1. AP pelvis

Figure 1. AP pelvis

Figure 2: Lateral view of left hip 

Figure 2: Lateral view of left hip 

Figure 3: Lateral view of right hip

Figure 3: Lateral view of right hip

Avascular necrosis (AVN) of the bilateral femoral heads

This patient’s AVN is more advanced on the right hip compared to the left, with demonstrated right-sided cortical collapse, subchondral cyst formation, and remodeling of the femoral head and acetabulum. The left hip displays increased density and sclerosis. 

Definition and Epidemiology:

Avascular necrosis (AVN) of the femoral head refers to a decrease in blood flow to the femoral head that ultimately leads to cell death, fracture, and collapse of the articular surface.  The demographics of the disease vary based on the underlying cause of AVN. Across all causes, the average age at presentation ranges from 35-45 years, and males are affected up to three times more commonly than females (Kaushik, Das, & Cui, 2012).  

Pathophysiology and Risk Factors:

The exact underlying pathophysiology of AVN is controversial, but numerous traumatic and atraumatic causes have been identified that lead to interruption of the vascular supply to the femoral head and/or direct death of osteophytes and bone marrow. Risk factors for 75-90% of cases include hip trauma (injury to medial femoral circumflex artery), chronic steroid use, and alcoholism (Mont & Hungerford, 1995). Other risk factors include gout, sickle cell disease, Legg-Calve-Perthes disease, Caisson disease (aka “the bends”), myeloproliferative disorders, hypercoagulable states, hyperlipidemia, pregnancy, and smoking (Moya-Angeler, Gianakos, Villa, Ni, & Lane, 2015).   

Making the Diagnosis:

Typically, patients present with insidious onset of pain, pain with climbing stairs, and anterior hip pain. On physical exam, presentation may range from painless range of motion to severe hip pain with internal rotation. Plain radiographs are the first-line imaging modality of choice. MRI should be obtained when radiographs are negative but clinical suspicion for AVN remains high (Table 1). Multiple staging systems have been created to characterize the breadth of this disease. The modified Ficat Classification system is the most widely utilized, but it was invented prior to the advent of MRI and relies solely on x-ray imaging (Table 2) (Mont, et al., 2006)

Table        SEQ Table \* ARABIC     1      . Imaging studies for AVN of the femoral head (orthobullets.com)

Table 1. Imaging studies for AVN of the femoral head (orthobullets.com)

Table 2. Modified Ficat Staging System        CITATION Fic85 \l 1033     (Ficat, 1985)

Table 2. Modified Ficat Staging System (Ficat, 1985)

Why early diagnosis matters!

AVN ultimately leads to collapse of the femoral head and severe osteoarthritis requiring total hip arthroplasty. Early diagnosis allows for surgical procedures (core decompression, bone grafting) that preserve the femoral head and may delay the need for total arthroplasty. This is especially important for the young adults most affected by this disease who are likely to outlive their joint prosthesis and require revision at a later age. AVN is often multifocal, and clinical signs and symptoms are quite subtle in the early stages. Therefore, diagnosis of atraumatic AVN at one site should prompt evaluation of other high-risk sites, or a search underlying risk factors. In particular, greater than 80% of non-traumatic AVN in the femoral head is bilateral, so imaging of the full pelvis and contralateral hip should be obtained (Hauzeur, Pasteels, & Orloff, 1987)

Treatment:

For Ficat stages 0-II, bisphosphonates are used to prevent femoral head collapse. Alendronate has been shown to reduce pain, improve articular function, and slow collapse progression in adults with AVN in some trials, but other studies have shown no benefit (Luo, Lin, Zhong, Yan, & Wang, 2014). In these early stages, operative interventions such as core decompression and/or bone grafting are available to stimulate angiogenesis and promote healing.  For post-collapse stages (Ficat III-IV), operative interventions are required and include total hip replacement, hip resurfacing, or arthrodesis.

Case Resolution:

This patient was diagnosed with bilateral AVN at Ficat stage IV in his right hip and Ficat stage II in his left hip. His sickle cell disease and use of chronic oral steroids increased his risk for this condition. Ultimately, his hip pain did not require acute intervention or hospital admission, so he was referred to the orthopedic outpatient clinic for follow up and will require operative intervention.

Pearls:

  • Consider AVN in the differential diagnosis when patients present with insidious onset of pain, pain with climbing stairs, and/or anterior hip pain
  • Plain films are first-line imaging, but MRI (not CT) is gold standard for diagnosis
  • Early diagnosis may allow for surgical interventions that delay the need for total hip arthroplasty

    Faculty Reviewer: Dr. Jeff Feden
     

References:

Ficat, R. (1985). Idiopathic Bone Necrosis of the Femoral Head. Early Diagnosis and Treatment. J Bone Joint Surg Br, 3-9.

Hauzeur, J., Pasteels, J., & Orloff, S. (1987). Bilateral non-traumatic aseptic osteonecrosis in the femoral head. An experimental study of incidence. J Bone Joint Surg Am, 1221-5.

Kaushik, A., Das, A., & Cui, Q. (2012). Osteonecrosis of the femoral head: An update in year 2012. World J Orthop, 49-57.

Luo, R.-b., Lin, T., Zhong, H.-M., Yan, S.-G., & Wang, J.-A. (2014). Evidence for Using Alendronate to Treat Adult Avascular Necrosis of the Femoral Head: A Systematic Review. Med Sci Monit, 2439-2447.

Mont, M., & Hungerford, D. (1995). Non-traumatic avascular necrosis of the femoral head. J Bone Joint Surg Am, 459.

Mont, M., Marulanda, G., Jones, L., Saleh, K., Gordon, N., Hungerford, D., & Steinberg, M. (2006). Systematic analysis of classification systems for osteonecrosis of the femoral head. J Bone Joint Surg Am, 16-26.

Moya-Angeler, J., Gianakos, A., Villa, J., Ni, A., & Lane, J. (2015). Current concepts on osteonecrosis of the femoral head. World J Orthop, 590-601.