Knee Injury – Distance Running

Dwan Perry, DO

Mary L. Ireland, MD

An Equal Opportunity University

History

• ID: 37 year-old male• Sport: Former collegiate cross country

athlete, current recreational runner• CC: Right Knee Pain

An Equal Opportunity University

History

• HPI: Insidious onset of intermittent, sharp right knee pain over the last month

An Equal Opportunity University

History

• Competes in several races per year• Reports a recent increase in mileage

averaging 12-13 mi/day• Onset of medial sided knee pain with

runs and prolonged walking• Has tried cryotherapy and over-the-

counter analgesics with mild relief

An Equal Opportunity University

History

• Denies recent trauma, swelling, or radiating symptoms

• No recent changes in shoes, running style or surface

An Equal Opportunity University

History

• Past Medical History: None• Past Surgical History: None• Social History: Employed full time as a

physician, non-smoker, no illicit drug use

• Medications: OTC NSAIDs PRN• Allergies: None

An Equal Opportunity University

Physical Exam

• Athletic white male in no acute distress• Tenderness to palpation over the medial

tibial plateau just proximal to the pes anserine tendon insertion

• No joint line tenderness or palpable effusion

• Full ROM at the knee

An Equal Opportunity University

Physical Exam

• No significant pain with resisted knee flexion or extension

• Neurovasularly intact distally • Negative Lachman’s, McMurray’s,

anterior and posterior drawer testing, Stable to varus and valgus stress (0°/30°)

• Otherwise, normal exam of the BLE

An Equal Opportunity University

Imaging• Radiographs of the Bilateral Knee:

1. No evidence of fracture or loose bodies.

• MRI of the Right Knee without Contrast:

1. Reactive bone marrow edema in the medial tibial plateau without overlying meniscal tear or significant cartilage loss.

2. Irregular edema within the fibular head indicative of early arthrosis affecting the

proximal tibiofibular articulation

An Equal Opportunity University

An Equal Opportunity University

T2 Axial A1

#19, 20,

21, 22

An Equal Opportunity University

T2 Coronal A2

#13, 14,

15, 16

An Equal Opportunity University

T2 Sagittal A4

#14, 15

16, 17

Discussion

An Equal Opportunity University

Differential Diagnosis

1. Medial Meniscus Injury

2. Tibial Stress Fracture

3. Articular Cartilage Defect of the Medial or Patellofemoral Compartment

4. Pes Anserine Bursitis

An Equal Opportunity University

Final Diagnosis

Anteromedial Proximal Tibial Plateau Stress Fracture

An Equal Opportunity University

Treatment and Outcomes

• Cessation of the painful activities• Gradual return to running once

asymptomatic• Upon return to running, pain returned• Another period of relative rest

An Equal Opportunity University

Treatment and Outcomes

• After resolution of pain, the patient was able to return to running with no recurrence of pain at one year after initial presentation.

An Equal Opportunity University

Discussion

An Equal Opportunity University

Stress Fractures

• Repetitive and excess stress• Acceleration of normal bone remodeling• Microfractures Stress Reaction

Stress Fractures • Imbalance of bone repair

– Caused by intrinsic and extrinsic factors•

An Equal Opportunity University

Risk Factors

• Intrinsic Factors– Metabolic state (Vit D, EA, etc)– Menstrual patterns – Fitness level– Anatomic alignment– Microscopic bone structure– Bone vascularity

An Equal Opportunity University

Risk Factors

• Extrinsic factors– Training regimen– Dietary habits– Equipment

An Equal Opportunity University

Location

• Tibia (23.6%)• Tarsal Navicular (17.6%)• Metatarsal (16.2%)• Fibula (15.5%)• Femur (6.6%)• Pelvis (1.6%)• Spine (0.6%)

An Equal Opportunity University

Who does this effect

• Repetitive, HIT (athletes, military recruits)

• Recreational Runners (25 mi/week)• W >M• Low Bone Mineral Density• Smokers• Greater than 10 EtOH drinks per week

An Equal Opportunity University

History

• Insidious onset of pain • Recent change in training habits or

equipment• Dietary hx (Ca, Vit D, Prot, ETOH,

caffeine)• PMH of endocrinopathies, autoimmune

d/o, eating d/o, depression, GERD

An Equal Opportunity University

Physical Exam

• Tenderness over the affected bone• Hop Test (Tibia)• Fulcrum Test (Femur)• Spinal Extension Test (Pars)• Bradycardia, orthostatic hypotension,

and stigmata of eating disorders

An Equal Opportunity University

Differential Dx

• Vary based on location• Tendinopathy• Compartment Syndrome• MTSS• Malignancy

An Equal Opportunity University

Imaging

• Plain XRs– Acuity of injury– Cortical bone involvement

• Early: subtle radiolucency or poor cortex definition

• Late (weeks to months): Sclerosis of endosteum and periosteal elevation

– Cancellous bone involvement• Band of sclerosis perpendicular to trabeculae

An Equal Opportunity University

Imaging

• Plain XRs– Findings lag by weeks– May repeat in 2 wks to see fracture

An Equal Opportunity University

Imaging

• MRI– Fluid sensitive sequences helpful– Show endosteal marrow and periosteal

edema• Bone Scan

– Increased uptake within days to weeks

An Equal Opportunity University

Imaging

• US– Good for relatively superficial bones– Step-off– Hypoechoic band– Periosteal reaction– Hyperechoic callus formation– Hypervascularity with PDI

An Equal Opportunity University

Lab Workup

• CBC/CMP• Vit D• TSH/PTH• ESR• UPT, Prolactin, Estradiol, FSH, LH

– If suspect Female Athlete Triad

An Equal Opportunity University

Treatment

• Nonsurgical– Rest and immobilization– Vit D/Ca supplement if necessary– Biphosphonates controversial

• Surgical – For high risk Fx (Fem neck, Ant Tib,

Navicular, Talus, Prox 2nd MT, Pars)

An Equal Opportunity University

Thank You

An Equal Opportunity University