Skin Lesions

Description of a skin lesion

When describing a skin lesion, it is important to note the following features:

• Size
• Type
• Shape and symmetry
• Colour and pigmentation
• Surface features (smooth; rough)
• Distribution over the body (extensor surfaces; flexor surfaces)

Lesions may be further subdivided into primary and secondary lesions:

Primary lesion

 An area of tissue with impaired function due to damage by trauma or disease.

Secondary lesion

 A lesion arising as a consequence of any primary lesion.

1) Types of skin lesions

Lesions can be classified as primary or secondary lesions. Primary lesions can be classified into the following types:

• Macule
• Patch
• Papule
• Nodule
• Plaque 
• Vesicle
• Bulla
• Pustule
• Abscess

Secondary lesions can be classified into the following types:

• Scale
• Crust
• Ulcer
• Fissure
• Atrophy
• Lichenification

Flat lesions

Macule

A flat lesion, less than 0.5cm in diameter with an area of colour change. 

Conditions in which macules appear:

• Small pox
• Purpura
• Roseola

Patch

A lesion which is more than 0.5cm in diameter with an area of colour change. 

Examples of a patch:

• Measles
• Flat moles
• Freckles

Raised lesions

Papule

A palpable lesion which is less than 0.5cm in diameter.

Examples of papules:

• Actinic jeratosis
• Senile sebaceous hyperplasia
• Dermatofibroma

Nodule

 A papule with a diameter of more than 0.5cm.

Examples of nodules:

• Herpes simplex virus 
• Rheumatoid arthritis 

Plaque

 A papule with a diameter of more than 0.5cm. 

Examples of plaques:

• Psoriasis typically present with a plaque-like lesion

Fluid-filled lesions

Vesicles

 Fluid-filled lesions with a diameter less than 0.5cm.

Examples of vesicles:

• Impetigo
• Contact dermatitis
• Insect bites

Bulla

 A fluid-filled lesion with a diameter more than 0.5cm.

Examples of bullae:

• Bullous pemphigoid 
• Pemphigus 
• Dermatitis herpetiformis 
• Chronic bullous dermatosis 
• Cutaneous radiation syndrome
• Epidermolysis Bullosa

Pustule

 A fluid-filled vesicle containing neutrophils (ie pus).

Examples of causes of pustules-

• Acne vulgaris
• Rosacea
• Folliculitis

Abscess

A fluid-filled lesion containing neutrophils and is more than 0.5cm in diameter. Bacterial infections of skin such as Staphylococcus Aureus can cause abscesses on the skin. 

Secondary lesions

Scales

 Epidermal cells produced by abnormal keratinisation of the skin which have died and then been shed.

Crust

 A dried collection of serum and cellular exudates.

Ulcer

 A discontinuation of an epithelial lining extending into the epidermis/dermis.

Example of ulcers-

• Arterial ulcer- caused by ischaemia and are usually located on the lateral aspect of the ankle or distal ends of the digits of the lower limbs
• Venous ulcer- due to valvular insufficiency of the veins 
• Neuropathic ulcer- related to sensory loss in the lower limbs, most common in diabetes

Fissure

 A linear discontinuation of the epithelial lining with a sharply demarcated margin, which can extend in to the dermis.

Fissures may occur as a consequence of the primary lesions mentioned or may also occur in response to-

• Scratching
• Trauma
• Infection.

Atrophy

 A thinning in the epidermis/dermis which in turn leads to depression of the skin. 

Lichenification

Thickening of the epidermis which may be caused by scratching.

Examples of lichenification-

• Eczema
• Contact dermatitis.

2) Colour-

Examples of colour changes in lesions:

Red/purple

Erythema- redness due to increased blood flow to blood vessels (vasodilatation) in that area.

Purpura- red/purple discolouration due to extravasation of blood into the skin from a blood vessel.

Brown

Melanin- a pigment found in the skin which gives a brown discolouration.

Haemosiderin- the breakdown product of haemoglobin so can follow on from purpura and appears as a brown discolouration.

Yellow

Lipid deposition- xanthelasma (cholesterol deposits around the eyelids) and xanthomata (cholesterol deposits in the tendons) can occur in hyperlipidaemia disorders.

Bilirubin- yellow discolouration due to jaundice (which is defined as bilirubin >35µmol)

3) Describe the surface features

Normal- lesion lies below skin surface

Or-There may be evidence at the skin surface such as-

Break in epithelial surface- exudate, crust, ulcer or a fissure.

Change in the size of epidermis/dermis-lichenificationor epidermal/dermal atrophy.

Change in the stratum corneum (the outermost layer of the epithelium composed of dead cells)-

Hyperkeratinosis- thickening of the stratum corneum due to increased keratin deposition in these cells.

Scales

4) Define the area involving the lesion-

Is the border well or poorly defined?

Look at the centre of the lesion- is it continuous with the rest of the lesion or is it raised/depressed?

5) Desribe the shape of the lesion-

The shape of the area on the skin surface- is it round, oval or irregular?

Overall shape of the lesion- spherical, domed, pedunculated (lesion attached to skin by a narrow stalk), flat-topped.

6) Findings on palpation-

Consistency-

is it soft, firm, hard or indurated (can feel thickening within the lesion)?     

or the lesion could have the consistency of normal skin.

Conclusion-

When describing a skin lesion consider the six points covered-

1) type of lesion,

2) colour of lesion,

3) surface features,

4) area involved,

5) shape of lesion,

6) findings of palpation.

OSCE example-

Example OSCE station:

"Please describe the lesion on the right."

In order to describe the lesion follow the 6 steps detailed above-

1) Type-

• This is a primary lesion as it is a pathology in its own right rather than a consequence of an existing pathology, thus you can rule out secondary lesions such as scale, crust, ulcer etc.
• It is a non-raised lesion- thus you can rule out raised lesion types such as papule, nodule and plaque
• There is no fluid so you can rule out fluid-filled lesions such as pustule and abscess, vesicle and bulla
• Thus the remaining two are macule and patch depending on the size of lesion, if it is >0.5cm it is a patch and <0.5cm it is a macule

2) Colour- the lesion is dark, a potential cause of this colour could be the pigment melannin

3) Describe the surface features- this is a non-raised lesion which lies below the skin surface

4) Define the area involving the lesion- the lesion has a poorly defined border

5) Describe the shape of the lesion- the lesion has an irregular shape

6) Findings on palpation- is it hard vs. soft?

  firm vs. moveable?

Thus a summary of the description of this lesion could be something along the lines of:

"This is a dark, non-raised macular lesion with a poorly defined border and an irregular shape. Given the dark discolouration and the nature of the shape and the lesion's border, a possible cause could be melanoma."

Tibia Shaft Fractures

Author: Joshua Blomberg

Topic updated on 12/20/13 7:26pm

Introduction

Epidemiology most common long bone fx Mechanism low energy fx pattern result of torsional injury indirect trauma fibula fx at different level Tscherne grade 0 / I soft tissue injury high energy fx pattern direct forces significant comminution fibula fx at same level severe soft tissue injury Tscherne II / III open fx Associated conditions soft tissue injury critical to outcome

Classification

Gustilo-Anderson Classification of Open Tibia Fxs Type I Limited periosteal stripping, wound < 1 cm Type II Mild to moderate periosteal stripping, wound 1-10 cm in length Type IIIA Significant soft tissue injury (often evidenced by a segmental fracture or comminution), significant periosteal stripping, no flap required    Type IIIB Significant periosteal stripping and soft tissue injury, flap required due to inadequate soft tissue coverage (STSG doesn't count). Treat proximal 1/3 fxs with gastrocnemius rotation flap, middle 1/3 fxs with soleus rotation flap, distal 1/3 fxs with free flap. Type IIIC Significant soft tissue injury (often evidenced by a segmental fracture or comminution), vascular injury requiring repair to maintain limb viability  For prognostic reasons, contaminated barnyard injuries, close range shotgun/high velocity gunshot injuries, and open fractures presenting over 24 hours from injury have all been later included in the grade III group.

Presentation

Symptoms pain, inability to bear weight Physical exam evaluate and document neurovascular status evaulate status of compartments palpation passive motion of toes intracompartmental pressure measurement if indicated pulse, sensation inspect soft tissue envelope for contusions, blisters, open wounds

Imaging

Radiographs recommended views full length AP and lateral views of affected tibia AP and lateral views of ipsilateral knee and ankle CT indications obtain when there is intra-articular fracture extension or suspicion of joint invovlement

Treatment of Closed Tibia Fractures

Nonoperative closed reduction / cast immobilization  indications closed low energy fxs with acceptable alignment < 5 degrees varus-valgus angulation < 10 degrees anterior/posterior angulation > 50% cortical apposition < 1 cm shortening < 10 degrees rotational alignment if displaced perform closed reduction under general anesthesia technique place in long leg cast and convert to functional brace at 4 weeks outcomes high success rate if acceptable alignment maintained risk of shortening with oblique fracture patterns  Operative external fixation indications can be useful for proximal or distal metaphyseal fxs complications pin tract infections common outcomes higher incidence of malalignment compared to IM nailing IM Nailing indications unacceptable alignment with casting soft tissue injury that will not tolerate casting segmental fx ipsilateral limb injury polytrauma bilateral tibia fx morbid obesity outcomes IM nailing leads to (verses external fixation)  decreased malalignment IM nailing leads to (versus closed treatment)  decrease time to union decreased time to weight bearing reamed vs. unreamed nails  reamed now proven superior to unreamed nails for treatment of both open and closed tibia fxs recent studies show no adverse effects of reaming (infection, nonunion) reamed nails associated with decreased hardware failure superior union rate decrease time to union percutaneous locking plate  indications proximal tibia fractures with inadequate proximal fixation from IM nailing distal tibia fractures with inadequate distal fixation from IM nail complications long plates may place superficial peroneal nerve at risk

Treatment of Open Tibia Fractures

Operative antibiotics, I&D indications all open fractures require an emergent I&D timing of I&D surgical debridement 6-8 hours after time of injury is preferred  grossly contaminated wounds are irrigated in emergency department antibiotics standard abx for open fractures (institution dependant) cephalosporin given for 24-48 hours in Grade I,II, and IIIA open fractures aminoglycoside added in Grade IIIB injuries  penicillin administered in farm injuries tetanus prophylaxis outcomes emergent and thorough surgical debridement is an important factor in determining outcome must remove all devitalized tissue including coritcal bone external fixation indications provisional external fixation an option for open fractures with staged IM nailing or plating falling out of favor in last decade indicated in children with open physis IM Nailing indications most open fx can be treated with IM nail within 24 hours contraindicated in children with open physis (use flexible nail or external fixation instead) outcomes for open fxs IM nailing vs. external fixation no difference with respect to infection rate union rate time to union IM nailing superior with respect to decreased malalignment decreased secondary surgeries shorter time to weight bearing reamed nails vs. unreamed nails reaming does not negatively affect union, infection, or need for additional surgeries in open tibia fractures  gapping at the fracture site is greatest risk for non-union  rhBMP-2 use in open tibial shaft fractures shown to   accelerate early fracture healing decrease need for subsequent bone-grafting decrease need for secondary invasive procedures decrease infection rate amputation indications no current scoring system to determine if an amputation should be performed relative indications for amputation include significant soft tissue trauma warm ischemia > 6 hrs severe ipsilateral foot trauma outcomes LEAP study most important predictor of eventual amputation is the severity of ipsilateral extremity soft tissue injury  most important predictor of infection is transfer to definitive trauma center  study shows no significant difference in functional outcomes between amputation and salvage loss of plantar sensation is not an absolute indication for amputation

Technique

IM nailing of shaft fractures preparation anesthesia general anesthesia recommended positioning patient positioned supine on radiolucent table bring fluoro in from opposite, non-injured, side bump placed under ipsilateral hip leave full access to foot and ankle to help judge intraoperative length, rotation, and alignment of extremity tourniquet tourniquet placed on proximal thigh not typically inflated use in patients with vascular injury or significant bleeding associated with extensive soft tissue injuries NEVER inflate during reaming or nail insertion approach options include medial parapatellar most common starting point can lead to valgus malalignment when used to treat proximal fractures lateral parapatellar helps maintain reduction when nailing proximal 1/3 fractures requires mobile patella patellar tendon splitting gives direct access to start point can damage patellar tendon or lead to patella baja semiextended medial or lateral parapatellar used for proximal tibial fractures suprapatellar (transquadriceps tendon) requires special instruments can damage trochlea  starting point medial parapatellar tendon approach with knee flexed incision from inferior pole of patella to just above tibial tubercle identify medial edge of patellar tendon, incise peel fat pad off back of patellar tendon starting guidewire is place in line with medial aspect of lateral tibial spine on AP radiograph, just below articular margin on lateral view insert starting guide wire, ream semiextended lateral or medial parapatellar approach skin incision made along medial or lateral border of patella from superior pole of patella to upper 1/3 of patellar tendon knee should in be 5-30 degrees of flexion choice to go medial or lateral is based of mobility of patella in either direction open retinaculum and joint capsule to level of synovium free retropatellar fat pad from posterior surface of patellar tendon identify starting point as mentioned previously fracture reduction techniques spanning external fixation clamps femoral distractor small fragment plates/screws reaming reamed nails superior to unreamed nails in closed fractures  be sure tourniquet is released advance reamers slowly at high speed overream by 1.0mm to facilitate nail insertion confirm guide wire is appropriately placed prior to reaming nail insertion insert nail in slight external rotation to move distal interlocking screws anteriorly decreasing risk of NVS injury if nail does not pass, remove and ream 0.5-1.0mm more locking screws statically lock proximal and distally for rotational stability no indication for dynamic locking acutely number of interlocking screws is controversial two proximal and two distal screws in presence of <50% coritcal contact consider 3 interlock screws in short segment of distal or proximal shaft fracture IM nailing of proximal third fractures proximal third fractures technique high incidence of valgus and procurvatum malalignment    techniques to prevent malalignment include      consider blocking screws to hold reduction while passing nail  use screws posterior to the nail in the proximal segment to prevent procurvatum   use screws lateral to the nail in the proximal segment to prevent valgus blocking screws increase construct stiffness  use a more lateral than usual starting point to prevent valgus insertion technique critically important must be parallel to both lateral and anterior cortex tibial nailing in semi-extended knee position prevents apex anterior or procurvatum deformity  application of a provisional anterior unicortical plate useful to prevent procurvatum and anterior translation of the proximal fragment

Complications

Knee pain >50% anterior knee pain with IM nailing  occurs with patellar tendon splitting and paratendon approach  pain relief unpredictable with nail removal lateral radiograph is best radiographic views to make sure nail is not too proud proximally  Malunion  high incidence of valgus and procurvatum (apex anterior) malalignment in proximal third fractures varus malunion leads to ipsilateral ankle pain and stiffness  chronic angular deformity is defined by the proximal and distal anatomical/mechanical axis of each segment center of rotation of angulation is intersection of proximal and distal axes Nonunion definition delayed union if union at 6-9 mos. nonunion if no healing after 9 mos. treatment nail dynamization if axially stable exchange nailing if not axially stable   reamed exchange nailing most appropriate for aseptic, diaphyseal tibial nonunions with less than 30% cortical bone loss.   posterolateral bone grafting if significant bone loss non-invasive techniques (electrical stimulation, US) BMP-7 (OP-1) has been shown equivalent to autograft  compression plating has been shown to have 92-96% union rate after open tibial fractures initially treated with external fixation  Malrotation most commonly occurs after IM nailing of distal 1/3 fractures  can assess tibial rotation by obtaining perfect lateral fluoroscopic image of knee, then rotating c-arm 105-110 degrees to obtain mortise view of ipsilateral ankle Compartment syndrome incidence 1-9% can occur in both closed and open tibia shaft fxs diagnosis high incidence of clinical suspicion pain out of proportion pain with passive stretch compartment pressure within 30mm Hg of diastolic BP is most sensitive diagnostic test treatment emergent four compartment fasciotomy outcome failure to recognize and treat compartment syndrome is most common reason for successful malpractice litigation against orthopaedic surgeons prevention increased compartment pressure found with traction (calcaneal)  leg positioning Nerve injury LISS plate application without opening for distal screw fixation near plate holes 11-13 putsuperficial peroneal nerve at risk of injury due to close proximity  transient peroneal nerve palsy can be seen after closed nailing  EHL weakness and 1st dorsal webspace decreased sensation treated nonoperatively; variable recovery is expected