Tibial Fractures

Tibial fractures

Anatomy

Tibia—85% of weight bearing
Fibula—for muscle attachment and ankle stability, NWB bone

Tibial blood supply

Sources

nutrient artery
branch of posterior tibial artery, penetrates tibialis post
enters junction of upper and middle 1/3rd, traverses cortex over 5cm

metaphyseal vessels
periosteal vessels
derived fromvessels of limb and run perpendicular to long axis of bone—not interrupted in fractures if Periosteum intact

apophyseal – vessels from insertion of muscles/ligaments

nutrient artery and metaphyseal vessels are endosteal supply—linear pattern. These are interrupted in fractures .
Cortical blood supply
inner 2/3=endosteal supply
outer 1/3=periosteal supply
Medullary(endosteal) supply is dominant in all healing phases of undisplaced fractures
Periosteal vessels alone are sufficient to support normal fracture repair
All veins drain to the periosteal surface

Classification

Gustillo 1976, 1984

Type ILaceration: Less than 1 cm long.

Contamination: Clean puncture (Compound from within)

Soft-Tissue: Little damage. No crush

Fracture: Usually simple transverse or short oblique. V. little comminution.

Type IILaceration: More than 1 cm long.

Contamination: Moderate contamination.

Soft-Tissue: No extensive soft-tissue damage, flap or avulsion. Slight or moderate crushing.

Fracture: Moderate comminution.

Type IIILaceration: Extensive Skin damage

Contamination: High degree of contamination.

Soft-Tissue: Extensive soft-tissue damage to skin muscle and neurovascular structures.

Fracture: Great deal of comminution and instability.

Includes(regardless of wound size):

High Velocity Trauma.

Gunshot injuries.

Farm injury.

IIIAAdequate soft tissue coverage of a fractured bone despite extensive laceration or flaps. High Vel Trauma with segmental or severely comminuted fractures regardless of laceration size

IIIBExtensive soft tissue injury with periosteal stripping and bony exposure. This is usually associated with massive contamination.

IIICOpen fracture associated with arterial injury requiring repair.Regardless of wound size or soft tissue injury.

infection rates of: type I 0-2%, type II 2-7% and, type III 10-25% (Gustillo 1990)

Gustillo 1987 / Sepsis rate / Amputation rate
IIIA / 5% (7%) / 2.5%
IIIB / 28% (10-50%) / 5.6%
IIIC / 8% (25-50%) / 25%

criticism of this classification
interobserver variability - apart from the type IIIC injury, there are no absolute rules that dictate that a specific injury falls into a particular class (60% concordance rate)
To improve the accuracy of the classification of open fractures, the extent and severity of the injury should be assessed only during surgery, after wound exploration and débridement, and not at presentation in theemergency department.

Byrd 1985

In 1985, Byrd et al formulated a new and simplified classification of fractures, based on the mechanism of the trauma and bone and soft tissue lesion. They recognized the importance of both the direct and indirect traumatic forces responsible for the bony lesions. Their classification is as follows:

Type I
Low-energy fractures
oblique or spiral fracture
clean-cut laceration smaller than 2 cm
Type II
Medium-energy trauma
displaced or comminuted fracture
laceration larger than 2 cm
myocutaneous contusion
Type III
High-energy trauma
severely displaced or comminuted fracture; segmental fracture or bone defect
laceration larger than 2 cm
loss of skin and muscle substance
Type IV
High-energy bursting trauma
crushing or avulsion with arterial damage requiring microvascular repair

Mangled Extremity Severity Score Johansen, 1990

Skeletal / soft-tissue injury
Low energy (stab; simple fracture; pistol gunshot wound)1
Medium energy (open or multiple fractures, dislocation)2
High energy (high speed MVA or rifle GSW) 3
Very high energy (high speed trauma + gross contamination) 4
Limb ischemia
Pulse reduced or absent but perfusion normal1*
Pulseless; paresthesias, diminished capillary refill 2*
Cool, paralyzed, insensate, numb3*
Shock
Systolic BP always > 90 mm Hg0
Hypotensive transiently1
Persistent hypotension2
Age (years)
< 300
30-501
> 502
* Score doubled for ischemia > 6 hours

According to Johansen’s study - a MESS score of greater than or equal to 7 had a 100% predictable value for amputation.
A prospective evaluation of the MESS (and also Limb Salvage Index (LSI); the Predictive Salvage Index (PSI); the Nerve Injury, Ischemia, Soft-Tissue Injury, Skeletal Injury, Shock, and Age of Patient Score (NISSSA); and the Hannover Fracture Scale-97 (HFS-97)) by Bosse (J Bone Joint Surg Am 2001) did confirm that low scores could be used to predict limb-salvage potential but failed to support the validity of the scores as predictors of amputation.

Management

Early management considerations

patient
resuscitation
other injuries
injured limb
ischaemia – reduce fractures immediately
compartment
wound
priority is to prevent further contamination of the wound
avoid multiple dressing changes in ED - raises the ultimate infection rate by a factor of 3 to 4
Fracture
Position limb safely and splint fracture

Importance of antibiotics

Patzakis 1974 was the first to conclusively demonstrate the importance of antibiotics in open fracture. In a randomised prospective trial he looked at 310 patients with open fractures and divided them into three groups: The infection rate in Group I who received no antibiotics was 13.9%, in Group II who received penicillin and streptomycin was 9.7% and in Group III who received cephalothin was 2.3%. The difference between groups I and III was statistically significant.
The lowest reported infection rate with various systemic antibioticregimens occurred with combination therapy with a cephalosporin and an aminoglycoside.
Quinolones are a promising alternative to intravenous antibiotics because they offer broad-spectrum antimicrobial coverage, are bactericidal, can be administered orally with less frequent dosing than intravenous antibiotics, and are well toleratedclinically.
soon as possible after the injury occurs because a delay >3 hours increases the risk of infection.
duration of therapy should be limited to 3 days, with repeated 3-day administration of antibiotics at wound closure, bone grafting, or any major surgical procedure.
Local administration of gentamicin soaked PMMA (polymethylmethacrylate) beads reduces the infection risk further. Advantages:
a high local concentration of antibiotics, often10 to 20 times higher than thatwith systemic administration
alow systemic concentration, whichprotects from the adverse effects ofaminoglycosides
a decreasedneed for the use of systemic aminoglycosides;
sealing of the wound from the external environmentwith film dressing.

Cessation of Smoking

Clin Orthop Relat Res. 1999 Aug;(365):184-200.

146 closed and Grade I open tibia shaft fractures treated withcast immobilization, external fixation, or intramedullary rod fixation
Two of the 44 patients who smoked had nonunions at the 1-year followup,whereas none of the patients who did not smoke had nonunions.
median time to clinical healing for patients who smoked (269 days) was significantly greater than that of patients who did not smoke (136 days).
There was a 69% delay in radiographic union in the group that smoked as interpreted by a radiologist blinded to the two groups. Statistical differences in clinical and radiographic healing rates
The current data suggest that tibias of patients who smoke who require treatment with intramedullary nailing or external fixation require more time to heal than do those of patients who do not smoke.

Am J Orthop. 2002 Sep

retrospectively review of 105 patients with 110 open tibia fractures treated with external fixator or intramedullary nail
Smokers had a union rate of 84% (52/62), and nonsmokers had a union rate of 94% (45/48), P = .10. For smokers in one arm of the study, time to union was significantly longer (P = .01), and there were more complications (P = .04).
Smoking decreased unions, slowed healing, and increased complications.

External bony fixation

Because of the high risk of infection, Gustillo recommended external fixation against IM nailing or plating.
A recent meta-analysis of open tibial fracturesrevealed that nail fixation is associated with lower reoperation rates, lower malunion rates, and lowerinfection rates than external fixation. It must be noted that the data apply to all grades of open tibialfractures, not necessarily Gustilo III’s as a separategroup.

Early Flap coverage

Marko GodinaEarly microsurgical reconstruction of complex trauma of the extremities.PRS 1986

532 patients with lower extremity wounds divided into 3 groups
Group 1coverage within 72 hours of injury
Group 2coverage between 72 hours and 3 months
Group 3coverage after 6 months

Flap failure / Infection / Time to union / LOS / No. operations
Group 1 / 0.75% / 1.5% / 6.8months / 27 days / 1.3
Group 2 / 12% / 17.5% / 12.3months / 130days / 4.1
Group 3 / 9.5% / 6% / 29months / 256days / 7.8

In a prospective review of open tibial fractures, Byrd advocated radical debridement of bone and soft tissue with flap coverage in the first 5 to 6 days after injury (acute phase) for the most severe injuries. The complication rate for Byrd Type III wounds averaged 18%. Fractures not treated by early muscle flaps predictably entered a colonized subacute phase that extended from 1–6 weeks postinjury. Complications after treatment with flaps during this phaseaveraged 50%. Some 4 to 6 weeks after untreated severe injuries, a chronic phase begins that is characterized by a granulating wound, adherent soft tissue and decreasing areas of infection. After soft tissue coverage, the complication rate forthis chronic group was 40%.
Issue is probably adequate debridement, copious irrigation and early coverage rather than absolute time frame

Bony Reconstruction

main aims of treatment are skeletal stabilisation, restoration of length and alignment, and preservation of optimum function
Segmental defects of greater than 2 cm are unlikely to heal spontaneously following skeletal stabilisation alone.
Those involving more than 50% of the circumference can heal spontaneously but often require additional treatment to restore normal volume and strength.
Bone loss in certain anatomical locations has a more favourable prognosis due to better blood supply and corresponding osteogenic potential.
Ways to bridge a bony defect
BoneGraft
BoneShortening
Bone Transport
Vascularized bone
Alloplasts and growth factors

Bone Grafting

Cancellous bone graft for small defects - often complicated by stress fractures if used for larger defects
Cortical bone grafts indicated for larger defects
A long period for revascularization is required. A long incorporating and remodeling time, undergoing creeping substitution, is necessary. Spontaneous stress fractures may occur late (reported to occur as many as 3 y after surgery).
late stress fractures causes pseudoarthrosis at the fracture site in approximately 33% of these patients.
Early bone grafting recommended (<12/52 post injury and post flap coverage)—reduces time to union
Best forwell vascularised defects <6cm treated with IM nailing although larger defects have been grafted by some units
Helps if fibula is intact—acts as a strut

Bone shortening and staged reconstruction

For defects in excess of 6 cm, one option is to shorten the bone at the time of the initial surgery, apply a circular frame and create a corticotomy through a healthy area of bone away from the zone of injury.
The bone can then be lengthened at the same time as obtaining bony union.
Should be considered if the associated soft-tissue defect is shorter than that of the bone. Shortening the leg will reduce the size of the soft-tissue defect and may avoid the need for a free flap.
In the upper limb, shortening of 2 to 4 cm may be tolerated without significant functional impairment, obviating the need for subsequent lengthening.

Bone transport

use of a frame to carry out callotasis or bone transport to bridge a defect
Circular frames (Illazarov) are now more popular than uniaxial devices since they confer greater stability and there is more flexibility in the configuration of the frame.
Gap defects 16-20cm reported with success
During the second operation for removal of pins, bone grafting is recommended for around the docking site to prevent fractures
Disadvantages
Main problem is the lengthy external fixation time (1 month for each cm of reconstruction)
Pin site infections
Stiffness of adjacent joints
Pain, neuropraxia due to stretching
Docking site fractures

Vascularised bone graft

May be free or pedicled
Free bone graft
Fibula most commonly used
Wei FC (PRS 2005) - One-stage reconstruction of composite bone and soft-tissue defects in traumatic lower extremities using:
vascularized fibula osteoseptocutaneous flaps
vascularized iliac osteocutaneous flaps
vascularized rib transfers with serratus anterior muscle and/or latissimus dorsi muscle transfers
can be used to bridge defects of up to 20 cm
advantage is that soft tissue reconstruction achieved at same time
disadvantages

usually a mismatch in size when used in the lower limb to bridge femoral or tibial defects and the graft may fracture. Prolonged partial weight-bearing may be required to minimise the incidence of this complication.
limited application for metaphyseal defects due to constraints in shape
A recent comparison of this method with bone transport in the femur indicated that superior results were obtained with the latter method (J Orthop Trauma 2003)
Most useful for reconstruction of forearm defects, although creation of a one bone forearm is another option

Pedicled fibula (tibialisation of fibula)
large graft of ipsilateral fibula is raised on a pedicle of peroneal and anterior tibial muscles and peroneal vessels. It is aligned and fixed to the tibia along its posterior long axis providing a sound mechanical and biological basis for union.

Alloplasts and growth factors

as yet, there is no osteogenic or osteoinductive material of proven clinical value for the treatment of significant post-traumatic bone loss in humans.
Osteoconductive materials such as calcium phosphate cement have been used to fill small bone defects following fractures, notably in the distal radius, the proximal humerus, the tibial plateauand the calcaneum
these materials are only suitable for use in relatively small contained metaphyseal defects since they have poor resistance to torsional, shear or bending stresses. These physical limitations and the absence of any osteoinductivity or osteogenicity render them unsuitable for use in the presence of extensive bone loss.

Complications of Fractures

avascular necrosis
delayed union
Inadequate blood supply
Infection (and in any open fracture)
Insufficient splintage
Distraction of fragments (traction, intact fellow bone)
Non union
Excessive motion
Gap
Poor blood supply
Malunion
Primary – fracture never reduced
Secondary – reduction not held
Malunion in a child will remodel provided the fracture is near a bone end and not mal-rotated.

Articular Reconstruction

Small defects can probably be ignored if there is no instability of the joint.
Larger defects will require consideration of the use of an allograft or an arthroplasty, in small joints of the fingers, consider arthrodesis
Fresh articular allografts following trauma have mainly been described in the knee, usually for fractures of the tibial plateau (defects of more than 3 cm in diameter and 1 cm deep) - indications for allografts are limited to younger patients with significant defects
Arthroplasty is available for most joints and is indicated in older patients. For some joints, such as the ankle, wrist and interphalangeal joints, fusion is a reasonable alternative.

Soft Tissue reconstruction

Principles

Early soft tissue coverage (3-7 days) after adequate debridement and fixation
Muscle that is traumatized, crushed, or affected by a compartment syndrome should not be transferred; free muscle transfer should be used instead.
Fasciocutaneous flaps are useful when dead space is minimal, when the flaps are pliable, and when they facilitate tendon gliding. They may restore sensibility to the affected area if the flap remains innervated.
in the presence of severe osseous injury, use of rotational flaps was notably more likely to lead to wound complications compared with free flaps

Musculocuneous vs random flaps for risk of infection

Mathes PRS 1990 – canine model
bacterial counts were significantly lower in the musculocutaneous flap wound
phagocytic activity of the leukocytes within musculocutaneous flap wound was 1.5 times greater than the leukocytes in the random-pattern flap
intracellular bacterial killing ratio of the musculocutaneous flap leukocyte was 83 percent versus 26 percent in the random-pattern flap leukocyte, a significant difference.

Musculocuneous vs fasciocutaneous flaps for risk of infection

Mathes PRS 1986 - Canine model
Area of skin necrosis secondary to bacterial inoculation was similar in the two flap types.
In wound spaces formed by the deep surface of the two flap types, a greater degree of inhibition and elimination of bacterial growth and more collagen deposition was seen in the musculocutaneous wound space than in the fasciocutaneous flap.
Gosain PRS 1990 – canine model
Muscle flap showed superior tissue ingrowth, rapid early augmentation of blood flow during first 24 hours
most rapid decline in bacterial counts at the undersurface of both flaps occurred within 24 hours, dropping significantly lower within musculocutaneous flaps.

Musculocutaneous vs cutaneous flaps for bone revascularization

Fisher PRS 1987
muscle of the musculocutaneous flap had a blood flow three times that of the skin of the cutaneous flap.
muscle flap was superior to a cutaneous flap in revascularizing isolated bone segments at 4 weeks.

Tissue expansion

The primary application is to resurface areas of unstable soft tissue or unsightly scar.
Because of high infection rates (5-30%), TE is more difficult in the leg than elsewhere.
Good results can be expected in the buttocks or thigh, but below the knee, Manders reports a failure rate of 50%.
Expanders are usually placed subcutaneously (just above the fascia) and inflation pressures should not exceed 40 mmHg to avoid compartment syndrome.
Use as big an expander as possible.
Plan for transverse, not axial advancement of tissue.
The ankle and foot are not suitable for TE.

Thigh coverage

local transposition
muscle flaps - gracilis, vastus lateralis, TFL, rectus abdominis, rectus femoris
fasciocutaneous flaps – medial thigh, lateral posterior thigh, anterolateral

Proximal 1/3rd