Senior Report 5.23

 

Case Presentation by Dr. Brandon Cheppa

Chief Complaint: “My foot hurts”

History of Present Illness:  This is a 40 year old male with a one day history of sudden right foot pain.  He states that last night he jumped over a fence and upon landing he had sudden onset of pain in his foot.  He states that he has barely been able to put weight on his foot and that walking is difficult.  The pain is constant, worsening, and he has never had pain in his foot like this before.  He denies any knee, hip, or back pain.  He denies any history of pain in any of his other joints.  He denies any head trauma, loss of consciousness, or numbness in any of his extremities.  He has not tried any medications and nothing seems to make it better or worse.

Review of Systems:  As per HPI

Past Medical, Family, and (or) social history:

Past Medical History:  Negative for Hypertension, Negative for diabetes

Past Surgical History: Denies any surgeries

Medications: None

Allergies: No known drug allergies

Social History:  Smokes cigarettes, denies alcohol, drugs, or intravenous drug use.

Family History: Unknown

Examination of organ system and body areas:

Vital signs: BP: 136/97, HR: 88, RR: 18, Temp 36.7 orally

Constitutional:  Patient appears comfortable, sitting in a wheelchair

HEENT:  Head is normocephalic, atraumatic, no tenderness to palpation, PERRLA, EOMI,

Neck:  Soft, supple, no masses, no cervical midlinetenderness

Cardiovascular:  Normal heart sounds

Respiratory:  Normal breathsounds

Gastrointestinal:  Soft, non-tender, non-distended, no palpable masses

Skin: No lacerations, no open lesions, no rashes seen

Neurological:  Patient is AOx3, acting appropriately, No sensory deficits,  grossly moving all extremities well, normal facial symmetry.  He has a hobbling gait favoring his left side and is unable to put weight on his right leg.

Back: No midline tenderness of entire spine

Skin:  No ecchymosis or breaks in skin seen

Musculoskeletal:  Upper extremities and Left lower extremities have full range of motion at all joints with 5/5 strength to flexion and extension and have no swelling or deformities to palpation.  Focused exam of left lower extremity:  Full range of motion of hip and knee with 5/5 strength to flexion and extension.  Patient has no calf tenderness, no Achilles tendon tenderness.  Right ankle has no malleolar tenderness.  He has tenderness of his midfoot, it is red, swollen with no crepetus or fluctuence.  He has good symmetrical pules of both feet with good capillary refill and he is neurovascularly intact.

Labs: None

Images: Complete x-ray of the foot was obtained

Questions:

1) The x-ray obtained is concerning for which type of fracture?

A. Boxer’s fracture

B. Jones’ fracture

C. Lisfranc’s fracture

D. Maisonneuve fracture

E. Salter-Harris type IV fracture

2) What is the appropriate disposition for the patient?

A.  Ace wrap, crutches, non-weight baring, follow-up with orthopedic clinic in 1 week

B.  Ace wrap, “ortho shoe”, weight bare as tolerated, follow-up with orthopedic clinic in 1 week

C.  Immediate orthopedic consultation in the emergency department

D.  Posterior mold splint, crutches, non-weight baring, follow-up with orthopedic clinic the next day

3) What is the most common complication this patient will experience if this injury is not appropriately treated?

A.  Compartment syndrome

B.  Deep Venous Thrombosis

C.  Degenerative Arthritis

D.  Osteomyelitis

E.   Regional Pain Syndrome

Answers:

1)    C

2)    C

3)    C

Discussion:

A Lisfranc fracture is one part of the collective term Lisfranc Injury.  A Lisfranc injury can very in radiographic presentations, but are all centered around any injury to the tarsometatarsal joints, also known as Lisfranc’s joint.

The Lisfranc’s Joint is made up of the five metatarsals and their articulations with the three cuneiforms, the navicular bone, and the cuboid bone.  The biomechanical structure of the foot allows for passage of neurovascular bundles and connective tissues through the foot without being crushed by a person’s weight.  The metatarsal bones have a trapezoid shape and are arranged in an arch configuration using the second metatarsal as the “keystone”.  Under normal physiologic conditions the second metatarsal has very little motion compared to the other four metatarsal bones.

The Lisfranc ligament is the strongest of the tarsometarsal ligaments and connects the lateral surface of the medial cuneiform to the medial base of the fifth metatarsal.  There are no proximal ligaments between the bases of the first and second metatarsals, most likely due to the evolution of the foot from a primitive hand structure where the first metatarsal evolved from a primitive thumb.  There are ligamentous connections between the second through fifth metatarsal bones and all five have distal ligamentous connections.  One to two mm of dorsolateral displacement of the affected base of the second metatarsal can lead to 13-25% reduction of contact at the joint.  The dorsalis pedis artery and deep peroneal nerve can be compromised with this injury due to their locations in the foot.

Patients can injure this structure by many mechanisms and it usually results in a closed fracture.  Motor vehicle collisions, falls, and even pedestrians tripping on curbs can produce this injury.  It stems from forceful abduction of the forefoot of a plantar-flexed foot.  Windsurfers, motorcyclists, and people who get thrown off horses have been historically at risk for this injury.  Patients typically will present with pain, swelling to the midfoot, and difficulty placing weight on the injured extremity.  They may present with ecchymosis to the plantar surface of the midfoot, although not specific, it is suggestive of an injury.  A detailed history and physical exam with attention to other associated injuries such as at the knees, hips, and lower back will guide your work-up.

Complete x-rays of the foot will pick up a Lisfranc injury 90% of the time.  With high clinical suspicion, and a presumptive negative x-ray, you can elect to get “stress” views of the foot which requires the patient to place weight on the injured foot.  Often times this is difficult to accomplish due to significant pain, or lack of ability to interpret a “stressed-view” of a foot x-ray, therefore a CT scan will aid in diagnosis.

With the knowledge of the anatomy combined with the mechanism of force, on radiograph, a fracture at the base of the second metatarsal is pathognomonic of a disruption of the Lisfranc ligamentous complex.  The diagnosis is made radiographically on the anteriorposterior view when there is a gap greater than 1 mm between the bases of the first and second metatarsals.  Other radiographic findings may be present or can lend to the diagnosis such as loss of alignment of the medial edge of the base of the second metatarsal with the medial edge of the middle cuneiform; loss of alignment of the lateral border of the third metatarsal shift with the lateral border of the lateral cuneiform; or loss of alignment of the medial border of the fourth metatarsal with the medial border of the cuboid.  If radiographs are unequivocal, and suspicion is still high, there is a chance of a spontaneously reduced dislocation.

Patient who sustain a Lisfranc injury require an emergency room orthopedic consultation and are to be made non-weight baring until their evaluation.  This is due to the large degree of instability of the joint that could lead to significant disability, and the potential for compartment syndrome and/or neurovascular injury.  Patients typically need to go to the operating room and undergo open or closed reduction with application of hardware.  Patients who have a Lisfranc sprain, will require below-knee casting, crutches, “RICE” therapy, and close orthopedic follow-up due to their potential for operative fixation.

The most common complication of an untreated Lisfranc injury is degenerative arthritis in the form of posttraumatic arthrosis.  Other less common complications include: compartment syndrome in the acute injury setting, deep venous thrombosis due to the amount of immobility, regional pain syndrome.

With early diagnosis and proper orthopedic intervention, 95% of patients at 3.5 years will have an excellent outcome.

The case revisited:

This gentlemen raised our suspicion for a midfoot injury based on his mechanism and physical exam.  We obtained foot radiographs and it showed a fracture of the base of the second metatarsal (circled in green), widening between the bases of the first and second metatarsal (measurement in blue), and a “fleck sign” (circled in red) which is a ligamentous disruption from the base of the second metatarsal.  This radiograph raised our suspicion for a Lisfranc injury and the orthopedic service was consulted.

They requested a CT scan due to the high potential for other associated fractures and it also showed a comminuted fracture of the medial cuneiform bone.

 

They opted to not take him for emergent surgery due to him having an ongoing underlying infection which was unknown during the initial patient encounter.  On reassessment, the patient had been experiencing painless, white discharge from his penis for the last two months.  The orthopedic service felt his infection could complicate his healing due to the chance that hardware will need to be applied during surgery.  They placed him in a cast, made him non-weight baring, and wanted him to follow-up in their clinic when his infection had resolved.  He was swabbed for Gonorrhea and Chlamydia, and treated for both of those infections including Trichomonas.  The results of his cultures were negative making Trichomonas the most likely cause of his infection.  At a follow-up visit in the orthopedic clinic, they felt there was not significant boney displacement and took him to the operating room to achieve “stressed” views of the foot under anesthesia.  They were satisfied with the stability of the joint and did not undergo any surgical intervention.  He was placed him in a non-weight baring cast and will continue to follow-up in the orthopedic clinic.

References:

Rosen’s, 7th edition, pp 681-695

Tintinalli’s, 6th edition, pp 1742-1746

Browner: Skeletal Trauma, 4th edition, 2008, Foot Trauma chapter

Ouzounian T.J., Shereff M.J.: In vitro determination of midfoot motion.  Foot Ankle  1989; 10:140-146.

Lu J., Ebraheim N.A., Skie M., et al: Radiographic and computed tomographic evaluation of Lisfranc dislocation: A cadaver study.  Foot Ankle Int  1997; 18:351-355.

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