Reconstruction Flashcards
1
Q
Define the following:
Osteoconduction
Osteoinduction
Osteogenesis
A
Osteoconduction: Graft acts as a scaffold for vascular tissue and mesenchymal cells
Osteoinduction: Stimulation of osteoprogenitor cells to differentiate into new bone forming cells
Osteogenesis: Transfer of vital osteoblasts to contribute to the growth of new bone
2
Q
Define allograft.
A
Graft from same species. Can provide osteoconduction and osteoinduction
3
Q
Define autograft.
A
Graft from same individual. Provides osteoconduction, osteoinduction and osteogenesis
4
Q
Define xenograft
A
Graft from non-human. Provides osteoconduction
5
Q
Define alloplastic graft
A
Graft from a synthetic material
6
Q
What is creeping substitution?
A
Process by which osteoclastic activity creates new vascular channels, with osteoblastic bone formation resulting in new haversian systems and osteogenesis from the graft
7
Q
What are the contraindications to a tibial bone graft?
A
-History of surgery in area or hardware
-Acute infection over soft tissue
Relative: History of metabolic bone disease
8
Q
How much bone can be harvested from a tibia?
A
-25 mL of cancellous bone
9
Q
What is the surgical technique of a tibia bone graft?
A
-Knee partially flexed and medially rotated, prepped
-Inject local with epi
-2 cm incision directly over palpable ridge of Gerdy’s tubercle. Parallel to tibial plateau and oblique to long axis of tibia
-Layers: Skin, subcutaneous tissue, periosteum
-Small portion of anterior tibialis and fascia lata stripped to allow acces to the cortex
-Fissure burr to make a corticotomy
-Curette inserted and rotated to harvest cancellous bone
-Avoid risk of perforation at superior edge
-More fat in this bone, need to compact it
-Pack bovine microfibrillar collagen (platelet aggregator matrix) or gelatin sponge (blood clot matrix)
-Layered closure
10
Q
What are complications associated with a tibia?
A
-Infection, gait disturbance, osteomyelitis, hematoma, seroma, fracture, violation of joint space.
11
Q
How is ecchymosis/swelling of the lower leg/ankle treated post-op with tibia graft?
A
-Decreased by keeping limb elevated
-Normal weight-bearing permitted but avoid strenuous activity
-Resolves on own
12
Q
How is a violation of the joint space or fracture of the tibia treated with a tibia graft?
A
-Non-weight bearing therapy
-Splinting
-Orthopedic surgery consult
13
Q
How is post-op osteomyelitis treated s/p tibia graft?
A
-MRI to eval depth of invasion/true osteomyelitis
-Orthopedic surgery consult
-Infectious disease and wound therapy consult
-Possible hyperbaric oxygen, long term antibiotic therapy
14
Q
How much bone can be obtained from an AICBG?
A
-50 cc (5 cm defect)
15
Q
What is the harvest site of an AICBG?
A
-Anterior superior iliac spine and tubercle of ilium
16
Q
What attaches to the ASIS?
A
-external oblique muscles
-tensor fascia lata
17
Q
What is most common nerve encountered during AICBG?
A
-Lateral cutaneous branch of iliohypogastic nerve L1, L2
18
Q
What is meralgia paresthetica and how is it caused?
A
-Dysesthesia and anesthesia of lateral thigh
-Damage to lateral femoral cutaneous nerve
-In 2.5% of patients this nerve comes within 1 cm of ASIS placing it at risk (usually most inferior nerve)
19
Q
What is the blood supply for the AICBG?
A
-Deep circumflex iliac artery
-Most common bleeding is from superior gluteal artery
20
Q
Describe the surgical technique for an anterior iliac crest bone graft.
A
-Retract skin medially
-4-6 cm incision placed 1-2 cm anterior to tubercle of ilium and 1 cm posterior to ASIS
-Infiltrate local w/ epi
-Incision is oblique along the cres
-Layers: Skin, subcutaneous tissue, scarpa’s fascia, muscular aponeurosis, periosteum
-Plan between TFL (laterally) and external oblique/transverse abdominus muscle (avascular plane)
-Medial approach (dissect iliacus)
-5 cm depth (cortical plate fuses), corticotomies
-Leave 3 cm bone to ASIS
-Bone wax or microfibrillar bovine collagen for hemostasis, may place drain
-Closure in layers
21
Q
How is post-op hematoma managed with an AICBG?
A
-If non expanding, pressure packing may be applied
-If expanding, require surgical exploration
22
Q
How is a massive hemorrhage managed during an AICBG?
A
-Likely from superior gluteal artery
-Caused by harvesting proximal to and or retracting too aggresively near the greater sciatic notch
-Tx: Exploration, ligation, embolization by IR
-Don’t blindly clip, can risk damage to sciatic nerve or superior gluteal nerve
23
Q
How is post-op seroma managed s/p AICBG?
A
Needle aspiration vs pressure dressing
24
Q
How is gait disturbance managed s/p AICBG?
A
-Usually self resolving. From excessive stripping of TFL
-Consult Physical therapy
25
How is a bony fracture managed from an AICBG?
-Caused by harvest too close to ASIS (stay at least 2 cm away)
-Pain management, bed rest
-Consult orthopedic surgery
26
How is an intra-abdominal injury managed from an AICBG?
-Surgical emergency, requires ex-lap
27
How is a post-op ileus managed from an AICBG?
-This is cessation of mechanical peristalsis of the bowel
-Tx: Bowel rest, electrolyte correction, NG tube for decompression, limit narcotics
-Consider pre-motility medicine like Reglan
-Usually self resolves, may obtain imaging to rule out bowel injury
28
How is sacroiliac instability managed s/p AICBG?
-Pain in lower back or pubis
-May need fusion if persistent pain
29
How is an abdominal wall hernia managed s/p AICBG?
-Risk factors: >4cm block harvest, female gender, obesity
-General surgery consultation
30
How much bone can be obtained from a posterior iliac crest?
100 cc (10 cm defect)
31
What is the blood supply to the posterior iliac crest?
-Subgluteal artery
32
Describe the surgical technique for a posterior iliac crest.
-Prone position, 210 degree reverse hip flexion
-6-10 curvilinear incision following course of posterior iliac crest
-Superior and inferior boundaries defined by superior L1-L3 and middle cluneal nerves S1-S3
-Incision ends (infeirorly), 3 cm lateral to gluteal crease
-Layers: Skin, subcutaneous, lumbodorsal fascia (seperates abdominal and gluteal musculature), and periosteum
-Gluteus maximus muscle stripped from tubercle
-5x5 cm osteotomy of lateral cortical plate
-Stay 4 cm from PSIS (avoid violation of sacroiliac joint)
-Hemostasis (avetene/bone wax)
-Layered closure, drain if needed
33
Where would bleeding be encountered during a posterior iliac crest graft, how is this managed?
-Superior gluteal artery
-Can cause post-op gluteal compartment syndrome
-Tx with ligation. may need ex lap or retroperitoneal approach
-May need IR embolization
34
How is a post-op urethral injury managed during a posterior iliac crest graft?
-Post-op hematuria, abdominal distention, ileus
-From excessive electrocautery near greater sciatic notch
-Urology consult indicated
-May need ureteral stent or surgical repair
35
What nerve injury can occur from a posterior iliac crest graft and how does it present?
-Cluneal nerves (posterior pelvic pain radiating to buttocks)
36
What type of graft is an anterolateral thigh flap, what is the artery/vein supply, how large of a graft/pedicle can be obtained?
-Fasciocutaneous (skin, muscle, fascia)
-Descending branch of lateral circumflex femoral artery
-5-7 cm pedicle (1.5-3 mm diameter vessel), very large flap 10-25 cm
37
Describe the surgical technique of an ALT flap.
-Draw line from anterior-superior iliac crest to lateral aspect of patella
-Draw a 5 cm circle at midpoint of line (likely where perforators can be identified)
-Center flap over perforators
-Make skin incision along medial margin of flap (skin, subcutaneous tissue, fascia over rectus femoris muscle)
-In subfascial plane, carry laterally until perforating vessels are identified
-Dissect the septum between the vastus lateralis and rectus femoris muscles to identify the pedicle
-Trace back pedicle to the lateral circumflex femoral artery. Incise flap around the lateral aspect
-Completely dissect the fasciocutaneous portion
-When ready, back cut on flap to desired size
-Vessels are clamped proximally and ligated
-Deliver flap to donor site
-Can usually close primarily, may require skin graft
38
How is muscle herniation managed s/p ALT flap?
-From vastus lateral and rectus femoris
-Requires exploration and repair. May require mesh
39
How is rectus femoris muscle necrosis managed s/p ALT flap?
-Uncommon
-From ligation of lateral circumflex artery proximal to take-off of the descending branch
-Preventative management: Place vessel loop at planned harvest spot and evaluate prior to definitive ligation
40
How is compartment syndrome managed s/p ALT flap?
-Release of deep fascia
-Debridement with VAC therapy
41
What type of flap, pedicle length/caliber, and vasculature is a radial forearm free flap?
-Fasciocutaneous flap
-Radial artery, venae comitantes or cephalic vein
-Long pedicle, 2-4 cm caliber
42
What are pre-op considerations for a radial forearm free flap?
-Allen test to determine acceptable ulnar collateralization
43
Describe the radial forearm harvest technique.
-Radial artery palpated and marked
-Flap drawn on skin. Distal aspect 1 cm from wrist crease
-Tourniquet utilized and inflated to 250 mmHg5
44
How is post-op tendon exposure, necrotic tissue treated s/p radial forearm harvest?
-Debride tissue, attempt second skin graft
-Allow to heal secondarily depending on size
45
How is post-op hand ischemia treated s/p radial forearm harvest?
-Normally avoided with Allen test or color flow doppler
-Can occur if radial artery is major blood supply of the hand, damage to ulnar artery, insufficient collateral blood flow
-Treat with interpositional vein graft to the divided stump from either the saphenous or cephalic vein
46
What is the typical size of a bone graft obtained from a fibular free flap.
Bony height: 9-15 mm
Length: 25 cm
47
What is the vascular supply of the fibula free flap?
Peroneal artery
Venous comitantes
48
What is the caliber and length of the pedicle for a fibula free flap?
1.5-2.5 mm caliber
2-6 cm length
49
How are the fasical components of the fibula classified?
-Anterior and posterior (separated by tibia and fibula with their interosseous septum)
-Anterior has an anterior and lateral subdivision (separated by the anterior intermuscular septum)
-Posterior divided into deep and superficial components by the transverse intermuscular septum
-Lateral and posterior are separated by the posterior intermuscular septum
50
What fascial plane/septum is the skin perforators located (for a skin paddle harvest)?
Posterior intermuscular septum
51
What medical co-morbidities would affect a fibular free flap harvest?
-CAD
-Peripheral vascular disease
-Smoking
-History of claudication
-History of edema
-History of venous thrombosis
-Prior trauma
52
What arteries should you palpate on pre-op exam for a fibula free flap harvest?
Palpate dorsalis pedis and posterior tibial pulses
-Modified allen test (apply pressure to dorsalis pedis artery and palpate for posterior tibial pulse and vice versa)
53
What imaging is relevant with a fibular free flap harvest?
-Magnetic resonance angiography
-Computed tomographic angiography
-Conventional angiogram
-Color flow dopler imaging
54
What are findings in arterial supply that would affect FFF?
-Kim-Lippert Classification:
-Type III: Hypoplastic/aplastic branching of infra-popliteal artery (10%). 3 subgroups either 2 vessel runoff or single vessel peronia arteria magna)
-Type IV: Hypoplastic (relative), aplastic (absolute): Perioneal artery caliber
55
Describe the fibular free flap technique.
-Tourniquet inflated 250-350 mmHg
-Place a long anterior curvilinear incision to transverse intermuscular septum, along anticipated skin paddle.
-Incise skin and soft tissue to the fascia overlying the peroneus muscle
-Identify intermuscular septum and located perforators to the skin (typically located in middle and distal thirds of fibula)
-Dissect along the length of the anterior aspect of the fibula (peroneus longus, peroneus brevis, extensor hallucius longus)
-Continue dissection along the bone to the medial aspect (interosseous membrane)
-Proximal and distal fibula bone cuts (save 6-8 cm on both ends to maintain ankle and knee stability)
-Make posterior skin buts down to subfascial plane
-Retract fibula laterally, transect interosseous membrane to separate fibula from tibia
-Distal peroneal artery and veins are identified. Ligate and transect distal pedicle
-Disect pedicle from distal to proximal
-Preserve cuff of muscle along fibula (saves nutrient branches to fibula bone)
-Transect hallucis longus and ligate pedicle proximally (more proximally, the longer and greater diameter the pedicle)
-Flap harvested and prepared
-Insertion and anastomosis
-Re-approximate lateral compartment, close in layered fashion in tension free. Skin graft likely required
56
Where is the best location to obtain a calvarial bone graft?
-Parietal area.
-2 cm away from midline and 2 cm away from squamous portion of temporal bone
-Accessed via coronal incision
57
Describe how the vessels exit and where the skin paddle is for a right and left mandibular defect?
Right mandibular defect: If obtaining a right fibula, vessels come out anteriorly if skin covers mucosal defect and posteriorly if skin paddle covers neck/external defect
Left fibular: Vessels come out anteriorly for external defect or posteriorly for mucosal coverage
Think hand on fibula. Fingers represent vessels and palm is the pedicle.
58
What are common recipient vessels for oral cavity and lower facial reconstruction?
-Facial artery/veing
-External jugular vein
59
What arteries are used if the facial artery is not sufficient as a recipient vessel?
-Lingual or superior thyroid artery
-Transverse cervical artery
60
What veins can be used if the external jugular cannot be used as a recipient?
-Internal jugular
-Should avoid anterior jugular (due to tracheostomy)
61
How are vessels handled during a neck dissection to best preserve if needed for reconstruction?
-Gently tied with silk ties or vascular clips and dissected sharply
-Avoid electrocautery
-Avoid excessive handling
62
What is the most common type of anastomosis?
-End to end
63
What are techniques to overcome vessel discrepancy?
-Trimming smaller vessel back
-Dilating smaller vessel gently
-Spatulation (Cut longitudinally of smaller vessel and suture to end of anastamosis)
-Bevel edge of smaller vessel up to 30 degrees
-End to side anastomosis
64
What type of suture is used for anastomoses?
-9/0 nylon with tapered point needle
65
How are veins vs arteries anastomosed microvascular surgery?
-Arteries: Hand sutured
-Veins: Venous couplers (best when vessels are same size
66
What is the most common causes of vascular failure of a flap?
-Venous congestion (4x more likely). Most likely occurs in first 48h
-Arterial thrombosis
67
How does aspirin work and how long should a patient be on it s/p microvascular surgery?
-Blocks thromboxane A2 production (blocks vasoconstrictor activity) and aids in platelet binding
-Usually started post-op and on for 30-90 days
68
How does heparin work and how is it used in microvascular surgery?
-Binds to antithrombin III. Prevents activation of factors 2, 12, 9, 10.
-Not used much due to risk of bleeding and hematoma formation
-Heparin irrigation utilized as a vessel irrigant. Helps with antithrombotic effects in vessel walls
69
How does dextran work and how is it used in microvascular surgery?
-Electrochemical and rheological effect on vessel wall and red blood cells
-Improve vascular patency
-Must test for antigenicity (or can cause pulmonary edema, respiratory distress, renal damage, cardiac overload)
70
What are the common causes of flap issues and how is it treated?
-Structural: Pedicle/perforator twisted, stretched or kinked, hematoma causing compression
-Treat by taking back to OR and exploring the flap
71
How is a pinprick test done?
-Medium gauge needle used to pierce flap
-Arterial occlusion will have minimal to no bleeding. Decreased turgor of tissue
-Venous occlusion will cause rapid bleed of dark blood. Increased tissue turgor
72
How is a tracheostomy preformed?
-Identify the thyroid notch, cricoid cartilage, SCM muscles, and sternal notch
-Half-way between sternal notch and cricoid cartilage, a transverse incision is marked (SCM Lateral most point)
-Local anesthetic to incisino
-Incision through skin, into subcutaneous tissue
-Blunt dissection until superficial layer of deep cervical fascia seen. Vertical incision through this to avoid damage to anterior jugular veins
-Strap muscles are next. The median raphe between the infrahyoid strap muscles are divided and retracted. Laterall retract sternohyoid and sternothyroid muscles
-Thyroid isthmus retracted superiorly
-Treachea visualized, divide pretracheal fascia
-Anesthesia deflates ETT
-Transverse incision made through membranous trachea between 2nd and 3rd rings. (T incision or Bjork flap)
-Anesthesia slowly removes ETT just superior to trach site
-Lubricated trach tube inserted
-Confirm end-tidal CO2
-Secure trach, remove previous ETT
73
Where is most common post-op bleeding from a trach, how is it managed?
-Usually from anterior jugular vein or inadequate control of vascular thyroid
-Avoid electrocautery intra-op due to recurrent laryngeal nerve
-Use bipolar cautery
-Use Surgicel if post-op bleeding
74
How is a tracheoesophageal fistula managed?
-Muscle flap to repair esophagus with prolonged bypass of esophagus with NG tube
75
What is the blood supply to a pectoralis major flap?
-Pectoral branch of thoracoacromial artery, lateral thoracic artery, superior thoracic artery and intercostal artery
-Venae comitantes of accompanying arteries, drain to axillary vein
76
What is the blood supply to the temporoparietal fascia flap?
-Superficial temporal artery and vein
-Auriculotemporal nerve
77
How is the facial nerve mapped with a temporoparietal fascia flap?
-Runds deep to the temporal fascia
-Line drawn from the tragus to a line 3 cm above and 2 cm lateral to the supraorbital rim surgically
-Frontal branch is 1.5 cm lateral and superior to the eyebrow
78
How is a temporoparietal fascia flap harvested?
-Doppler Superficial temporal artery
-Incision marked through preauricular crease in front of tragus. Extends superficially inta a hemicoronal incision
-Dissection through subcutaneous fat
-Release fascia with the desired pedicle from the underlying temporalis muscle
-Separate galea from temporoparietal fascia
-Release is completed in subgaleal areolar tissue (Merkel's space) down to zygomatic arch
-Subcutaneous tunnel should be formed to allow extension of flap to defect
79
How is alopecia avoided during temporoparietal fascia harvest?
-Deeper dissection deep to hair follicles
80
How is temporal hollowing treated s/p temporoparietal fasica harvest?
-Can volumize bone with hydroxyapatite. Fat grafting, custom implants
81
What are the components of the buccal fat pad, what is the blood supply?
-3 lobes: Anterior, intermediate and posterior
-Posterior has four extensions: Buccal, pterygoid, pterygopalatine, temporal
-Buccal artery, deep temporal branch of maxillary artery, superficial temporal artery
82
What is the limit of upper lip primary closure? What are techniques of primary closure?
-Defects up to 1/4 upper lip
-V incision
83
What is the limit of lower lip primary closure? What are the techniques?
-Defects up to 1/3 lower lip
-V or wedge resection
84
Describe an Abbe flap?
-For upper lip 1/3-2/3.
-Based on inferior labial artery
-Triangular wedge from lower lip is designed.
-Flap raised and transposed 180 degress and inset. Donor site closed directly
-Division occurs 21 days later
85
Describe a Karapandzic flap.
-Rotational advancement flap
-Remove lesion in rectangular full thickness fashion
-Semicircular partial thickness incisions in skin and mucosa are performed from the edge of the skind efect towards the nasolabial and labiomental folds bilaterally
-Vascular and nerves are identified and released to allow strech
-Incisions are not full thickness so facial nerves and branches are preserved
86
Describe an estlander Flap.
-For pericommissural defects
-Apex of flap made into the nasolabial or labiomental crease
-Flap transposed 180 degrees
-Results in smaller oral stoma and indistinct commisure which may require more surgery
87
Describe the classification for maxillary defects.
Brown Classification
Vertical:
-Class I: Defect of the mid-face or maxillary alveolus
-Class II: Defect includes oral-antral communication
-Class III: Includes inferior orbital rim
-Class IV: Includes exenteration of orbital contents
-Class V: Orbitomaxillary defects
-Class VI: Nasomaxillary defects
Horizontal:
-Class A: Central palatal defect
-Class B: 1/2 or less of unilateral palate/alveolous
-Class C: Anterior maxillary defect
-Class D: Greater than 1/2 palatal or alveolar defect
88
Which fibula laterality is best for maxillary defect?
-Contralateral fibula
-Skin paddle will be towards oral cavity
-Pedicle coming off posterior of flap (best for tunneling to neck for anastomosis)
89
How much bone can you obtain from a fibula?
-About 25-35 cm (depending on height of patient)
-Bone height varies from 9-15 mm
90
What is a normal three vessel runoff?
-Show the popliteal artery branches into the anterior tibial artery, posterior tibial artery and peroneal artery
-Commonly the peroneal artery branches from the posterior tibial artery
91
What is a double barrel fibular flap?
-Involves removal of a 1 cm segment of the fibular bony segment and the bone flap is folded upon itself to increase the height or reconstruction
92
What is an equinovarus deformity and how is it prevented? What nerve controls sensation to the atnerior and lateral calf and dorsum of the foot?
-Equinovarus deformity: Club food
-Injury to common peroneal nerve
-Iatrogenic dissection or excessive traction (Wraps posterolaterally around neck of fibula
-Leave 6-7 cm segment of bone attached to the knee, identify nerve early
93
How do you manage a positive margin with an ameloblastoma when re-constructed with a fibula?
-Requires re-resection
-Allow 6 weeks of healing (pedicle should have enough healing)
-Careful dissection
-Can graft gap with non-vascularized graft
94
What do you do if SCCa had a positive margin?
-Re-excision when feasible
-Adjuvant chemotherapy and radiation are recommended
95
What are the contraindications to a fibula free flap?-
-Peronea arteria magna (one dominant peroneal artery perfuses whole foot
-Two vessel runoff
-Open wound of the leg
96
What is the difference between hypoglobus and orbital dystopia?
-Hypoglobus is the inferior displacement of the globe due to lack of bony orbital support. Usually seen in trauma and midface reconstruction
-Orbital dystopia is the displacement of the entire orbit. Commonly seen in craniofacial patients. Can see horizontal hypertelorism or vertical discrepancy
97
What is the difference of hypernasality and hyponasality?
-Hypernasality: Airflow escapes into the nasal cavity. Often from velopharyngeal dysfunction, associated with multiple syndromes
-Hyponasality: Air passage into the nasal cavity is restricted as seen with enlarged tonsils, inflammation and swelling from any number of etiologies (common cold, deviated septum, tumors)
