Case 1—Unhappy Triad
Medial Collateral Ligament + Medial Meniscus + ACL
Cause: a lateral blow to the extended knee or excessive twisting of a flexed knee
 The MCL is tightly stretched when knee is extended so force to it while it is taut can tear it.
This concomitantly tears the medial meniscus due to their attachment to one another.
 The ACL serves as a pivot for rotary movements of the knee and is taut during flexion, and
may also tear subsequent to the MCL tear. This is because once the MCL is torn, it makes
the ACL more vulnerable, weaker and once that joint space is opens on the medial side the
knee can twist further and break the ACL. It is 10x more likely to tear than the PCL.
GAIT CYCLE
Stance Phase starts as Heel Strike and ends with Push Off
1. Heel Strike—dorsiflexors put heel on ground
2. Loading Response—knee extensors accept weight
3. Midstance—hip abductors stabilize pelvis
4. Terminal Stance—plantarflexors push off
Swing Phase starts after Push Off and ends when the heel strikes the ground
1. Preswing—plantarflexors and digit flexors push toe off
2. Initial Swing & Midswing—hip flexors and dorsiflexors lift up thigh and foot
3. Terminal swing—dorsiflexors and knee extensors make leg reach out in front
Stiff Legged Gait: one leg is fully extended at the knee during terminal swing phase of the swing period
and throughout the first half of the stance period (Heel Strike and Loading Response). In this case it is
due to the swelling of the joint which impairs movement, so that the knee is fully extended throughout
walking.
o Terminal Swing—need dorsiflexors and knee extensors
o Heel strike—need dorsiflexors
o Loading response—need knee extensors
Explanation of Symptoms
 Widening of medial joint space—due to torn MCL
 Diminished muscle mass—due to diminished quadriceps femoris (he can’t flex the knee since
the joint is swollen so he is losing muscle mass in the extensors)
 Bruising and Swelling—are over the areas of the torn ligaments



Tenderness below medial epicondyle—due to medial meniscus tear
Effusion of fluid around the knee—ruptured synovial membrane causes fluid to leak out. The
body also makes more synovial fluid as a defense mechanism when there is trauma to the knee.
Pain—caused by structures that are innervated at the joint: capsule, synovial membrane, and
periosteum of bone. These are innervated by the Tibial and Femoral Nerves. Ligaments are not
innervated.
Drawer Tests
o Anterior drawer sign: tibia is able to slide anteriorly under the fixed femur—ACL torn
o Posterior drawer sign: tibia is able to slide posteriorly under fixed femur—PCL tear
*PCL tears can occur when there is a force to the tibial tuberosity with the knee flexed.
Other Possible Damage to Joint
Articular Cartilage
Bruise of fracture at Tibial Plateau
Case 2-L5 Spinal Root Compression from Herniated Disk
Exam Findings
 Abnormal gait—characteristic of trendelenburg gait
o compression of superior gluteal n. L4-S1 resulting in weak gluteus medius and minimus
 Pain upon sitting
o gluteus maximus used—inferior gluteal n. L5-S2
 Flattening of normal Lordosis of lower back
o Deep muscles of back may not be supporting the spine perhaps due to compression of
dorsal rami
o Could also be due to hyperactive intrinsic back muscles
 Slight deviation of lower spine to right
o Could be linked to congenital hypolordosis or scoliosis which is more prone to herniated
disks
 Pain restricting flexion of lumbosacral spine
 Normal bilateral symmetric patellar and calcaneal tendon reflexes
o Intact femoral n. (quadriceps femoris) and intact tibial n. (gastrocnemius, soleus)
o Patellar tendon = L2-L4 (femoral)
o Achilles tendon = S1-S2
o These do not have L5 contributions
 Normal Ankle flexes
o Rules out sacral disc herniation
 Bilateral paraspinal muscle spasms felt upon palpation
o Symptom of hypolordosis
o Or could be reflex to reduce movement around injury site
 Straight Leg Raising Test—exacerbates pain; pain relieved upon lowering but returns with
dorsiflexion
o Pain felt upon raising of straight leg is positive for herniated disk
o Pain returns with dorsiflexion because anterior compartment of leg innervated by deep
fibular nerve (L4-S1)
 Numbness on medial right foot and areas of 1st and 2nd toes
o This is the L5 dermatome and superficial fibular nerve sensory area (L5-S2)
 Weakness in right big toe extension
o Deficiency in deep fibular nerve
Straight Leg Raising Test—impacts L5; used to test the sciatic nerve
Stretching the legs stretches the dura mater—L5 root has a dural sleeve that is pulled during
stretching—this is where the pain comes from since the nerves themselves are not innervated (for
example if you sever a nerve you do not feel pain but will feel numbness). So when you stretch the leg, it
stretches the sciatic nerve which pulls all the way back to the cauda equina and spinal cord with the
dura mater. When you dorsiflex you stretch it even more.
Radiculopathy—when a nerve root is injured
Sciatica—when pain radiates down the back of the thigh following the course of the sciatic nerve;
common manifestation of lumbar radiculopathy
Case 3—Trendelenburg Gait from Gluteal Injections
Patient’s Superior Gluteal Nerve is injured from a gluteal antibiotic injection
Trendelenburg Gait—The dropping of the uninjured hip when the same-sided foot is lifted off the
ground is called Trendelenburg's sign. To compensate, the person lurches their trunk towards the
injured side (to keep body balanced and to left drooping pelvis). It occurs when the nerve supply to the
abductors of the thigh (gluteus medius, gluteus minimus, and tensor fasciae latae) is disrupted due to
injury or disease (i.e. poliomyelitis), or when conditions such as an unreduced or congenital dislocation
of the hip joint exist.
Other possible structures to damage from improperly placed injections
Inferior Gluteal Nerve
Posterior Femoral Cutaneous Nerve
Sciatic Nerve
Superior and Inferior Gluteal Arteries and Veins
Best Location for Injection—Superolateral quadrant of buttock, just posterior and inferior to ASIS
Case 4—Anterior Compartment Syndrome
 Shin splits—AKA MTSS—repetitive microtrauma to Tibialis Anterior leading to small tearing of
periosteum of tibia and subsequent inflammation of anterior compartment.
 In this case, shin splints progressed to chronic syndrome and severe compartment syndrome
 Other Causes of Compartment Syndrome
o Infection
o When muscle mass exceeds space compartment allows
 Example: gymnasts are found to have sudden cases of Anterior Compartment
Syndrome. They usually have short stature, short tibia, smaller anterior
compartments, but very muscular. Onset is sudden: could be after one work-out
and suddenly develops severe pain (straw that breaks camel’s back)

Deep Fibular Nerve Compression—inflammation compresses nerve
o Loss of sensory distribution at first dorsal web space of foot
o Gait exhibits “Foot Slap”



Cannot dorsiflex foot when bringing it to the ground for the heel strike, so they
must flex their hip a little more to get it off the ground and then the foot slaps the
ground. Also the toes draw a little bit during swing phase.
Anterior Tibial Artery Compression—results in weak dorsalis pedis artery pulse
Fasciotomy—surgery to relieve pressure of the compartment
Case 5—Plantar Fasciitis
Plantar Fasciitis—inflammation of plantar fascia often caused by an overuse mechanism. Pain is felt on
the plantar surface of the foot and heel. It is worse in the morning during the first steps after getting out
of bed. Pain usually diminishes after 30-45 minutes with walking. It can recur after strenuous exercise or
when standing again after sitting for a long time. This is because the pain is worse whenever the plantar
fascia is initially stretched. It is alleviated once the fascia has been completely stretched.
Causes
• Repeated microtrauma from prolonged walking/running leads to collagen degeneration
• Excessive pronation (eversion while running) during running
• Progressive atrophy of heel fat pad with age
• High or low foot arches (more susceptible)
• Poorly fitted shoes without adequate arch support
Treatment
• Rest or “Relative Rest”
• Heel and Foot Stretching Exercises
• Shoe change/Orthotics/Arch support
• Night Splints
• Anti-inflammatory Meds/Corticosteroid
• Plantar Fasciotomy
Longitudinal Arches
• Medial longitudinal arch—supported by spring ligament (from sustentaculum tali to navicular)
and FHL tendon
• Lateral longitudinal arch—supported by long and short plantar ligaments and the fibularis
longus tendon
• Running causes disappearance of medial arch, greater wear on inner soles and heel, and
straining of spring ligament and long and short plantar ligaments
Other Possible Diagnoses
• Tibial Nerve Entrapment/Tarsal Tunnel Syndrome –pain is severe and worsens throughout day
• Subcalcaneal Bursitis – The retrocalcaneal bursa is located in the back of the ankle by the heel
where the tendo calcaneus connects the gastrocnemius and soleus muscles to the calcaneus
bone. Excessive use of ankle can cause irritation or inflammation of bursa; pain is worse upon
plantarflexion
• Plantar Abscess – collection of pus in tissue planes seen mostly in diabetics; pain is constant with
swelling and palpable abscess.
Case 6—Hip Fracture—Intracapsular
Supporting Symptoms
• right lower limb was shorter than the left, and laterally rotated.
• Hip was painful with passive motion and tender to palpation.
• Right trochanter was higher than the left
• Contour of upper femur was not smooth and symmetric as compared to the left (normal).
Explanation of Symptoms
• The shortening of the limb, extreme pain, and lateral rotation of the hip could indicate a
possible hip fracture (proximal femur fracture) or a hip dislocation.
• 9/10 hip dislocations are posterior, which result in shortening of the leg (because femoral head
is more superior to acetabulum sitting behind it and above it) and medial rotation, which does
not explain the findings in our patient.
• Anterior dislocations result with the femoral head inferior to acetabulum (lengthen
limb)
Femoral Neck Fractures are most common—neck is weakest part of bone and deals with a lot of stress;
most vulnerable in older women; avascular necrosis of head and neck from rupturing circumflex femoral
arteries. Pain is often
Intertrochanteric and Transcervical Fractures—usually result from indirect trauma (stepping down hard
off a step). The impact makes the fragments move up to shorten limb as well as muscle spasms shorten
it.
Intracapsular Fractures—occurring within hip joint or capsule; complicated by degeneration of femoral
head in children from avascular necrosis (bc they still have the artery to the head of the femur).
Estrogen helps maintain bone density so these are more common in elderly women.
Patient has intracapsular fracture of the neck of the femur
3x more likely in elderly women than men
Pain is relieved when lying down whereas intertrochanteric feels pain all the time
Treatment:
1. internal fixation—metal screws into the neck reinforcing it
2. arthroplasty—total hip replacement (less common)
3. follow up treatment—treat osteoporosis
Case 7—LCL Sprain of Ankle
LCL ligaments—weaker than MCL ligaments
Anterior Talofibular Ligament—most vulnerable and most likely torn in event of sprain
Posterior Talofibular Ligament
Calcaneofibular ligament
Many times the lateral malleolus can be fractured
Shearing Fractures—breaking the malleolus superior to ankle joint
Avulsion Fracture—breaking it inferior to ankle joint—bone fragment pulled off by ligament
attachment
Most times an ankle sprain is due to extreme INVERSION
Hematoma and bruising due to the breaking of the lateral malleolar arteries and lateral talar arteries
Edema—due to leakage of fluid from damaged tissues surrounding the ligament