Knee Injuries Idan Ilsar, MD Arthroscopy and Sport Injury Unit Department of Orthopaedic Surgery Hadassah – Hebrew University Medical Center

Today’s Menu Meniscal tears Anterior Cruciate Ligament (ACL) tears Stress fractures

Meniscal injuries Prevalence …… (under-reported) Surgical incidence is 60-70/100,000/y

Meniscal anatomy

Meniscal anatomy

Meniscal fibers orientation Most of the collagen fibers aligned longitudinally Some fibers aligned radially - to hold the longitudinal fibers together These longitudinally oriented fibers allow for dissipation of compressive forces via hoop stresses

Meniscus In the past: “vestigial remnants of a muscle within the knee” Meniscal tear “Cut it out”

Meniscus - functions In the present: Load sharers Shock absorber Secondary knee stabilizers Proprioception Joint lubrication Nutrition of articular cartilage

Tears of medial meniscus > lateral meniscus Meniscal motion in ROM Tears of medial meniscus > lateral meniscus LM>MM

Meniscal blood supply Peripheral 20-30% of MM Peripheral 10-25% of LM Periphery White Red Peripheral 20-30% of MM Peripheral 10-25% of LM

Meniscal tears

Patient’s history (traumatic) Twisting injury Swelling – after several hours-days (synovitis) Pain Limp Locking

Physical examination Swelling Intra-articular fluid Joint-line tenderness Locked knee (Quadriceps atrophy if prolonged)

McMurry Test

Apley’s Test

Imaging X-Ray Ultrasound CT Bone scan SPECT MRI

Knee x-ray AP (standing) Tunnel Lat

Standing vs. Prone Rt Knee, 41y male

X- ray Knee alignment Osteoarthritis Osteonecrosis (AVN) Chondrocalcinosis LBs (fracture)

Ultrasound Effusion Baker’s cyst Meniscal excursion But: Operator – dependent Can’t visualize interior aspects

CT scan Fractures Dislocations

MRI

Treatment Analgesics NSAIDS Rest, Ice, Compression, Elevation Elastic bandage Physical therapy

Arthroscopy

Outside-In repair

Suture meniscus

PHLM tear

PHMM tear

Future Options

Meniscus implant

ACL tear

ACL Anatomy ACL = two-bundle ligament small anteromedial large posterolateral

ACL Mechanics The anteromedial band is tight in flexion, providing the primary restraint, whereas the posterolateral portion of this ligament is tight in extension.

ACL History and PE Incidence: 30 cases /100 000 people/ year Noncontact deceleration, jumping, or cutting action Valgus-external rotation (hyperextension) A “pop” is frequently heard or felt Rapid swelling = hemarthrosis

Physical examination Test LACHMAN Anterior drawer PIVOT SHIFT

X-Ray SEGOND fracture avulsion fracture of the lateral capsule pathognomonic of ACL tear

MRI Normal ACL

MRI ACL Tear

Treatment Non operative If a nonoperative approach is chosen, it should include an aggressive rehabilitation program and counseling about activity level Early Rehab: Reduce swelling ROM Quad/Hamstrings

Treatment Non operative The use of a functional knee brace is controversial and has not been shown to reduce the incidence of re-injury significantly if a patient returns to high-level sports

Treatment Operative Primary repair was advocated by some authors in the 1950s Although the short-term results were encouraging, long-term retrospective and prospective reviews showed that as many as 40% to 50% failed within 5 years.

Treatment : Operative ACL Reconstruction Extraarticular Intraarticular Autografts : Patellar tendon Hamstring ligament double loop Allograft

ACL reconstruction Normal ACL Complete ACL tear= “empty notch”

ACL reconstruction surgery

Stress fracture

Overload injury Stress fracture Etiology: More load More repeats Combination The emphasis is CHANGE

X Ray

Bone Scan

Pathophysiology Wolff’s Law: change in external stress leads to change in shape and strength of bone bone re-models in response to stress ABRUPT Increase in duration, intensity, frequency without adequate rest (re-modeling) Stress fracture: imbalance between bone resorption and formation Microfracture -> continued load -> stress fracture

Anatomic Location Tibia - 39.5% Metatarsals - 21.6% Fibula - 12.2% Navicular - 8.0% Femur - 6.4% Pelvis - 1.9%

Tibial stress fracture Local tenderness over middle – distal 1/3rd No swelling/redness

Treatment

IDF study Recruits Shoes, insoles, Biphosphonates – no reduction of SF incidence Good night sleep, length of marches – 60% reduction FINESTONE, A., and C. MILGROM. How Stress Fracture Incidence Was Lowered in the Israeli Army: A 25-yr Struggle. Med. Sci. Sports Exerc.2008. 40(11S):S623-S629

Treatment "Rest"

“Rest” = relative rest Stationary cycling Elyptical Swimming Avoid running/jumping

Return to sports סרגל מאמצים

“Cousin” of stress fractures Shin Splints Medial tibial stress syndrome (MTSS) / tibial periostitis Runners, flat feet Tibia Diffuse tenderness “Cousin” of stress fractures Similar treatment

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