Internal Fracture Fixation in Patient with OsteoporosisPresenter: dr. Nicko PerdanaModerator: Dr. dr. Ismail, SpOT

Osteoporosis

• A systemic disease.• Primary or secondary• Primary occurs in an individual who has no

endocrinopathy or other disease state that would account for the changes in bone mass.

• Characterized by:– Decreased bone mass.– Deteriorated bone microarchitecture.

• In the elderly (≥ 65 years): the most contributing factor (75%) fractures caused by low energy fall.**Lucas TS, Einhorn TA: Osteoporosis: The role of the orthopaedist. J Am Acad Orthop Surg 1993;1:48-56

Site of Fracture• Generally involves the metaphyseal region of

skeleton.• Why metaphyseal?

– Composed mostly of cancellous bone.– Greater surface for bone turnover rate (compared with

cortical bone).

• Proximal femur, distal femur, proximal tibia, distal radius, proximal humerus.

Principles of Fx Management

• The goal of definitive fracture care in elderly patients: early restoration of function.

• Timely treatment (best condition < 48 hr).*• Evaluation of concurrent illness.• Preoperative management to optimize the

condition.• Procedure should be simple & minimal.• Early weight bearing.

*Aharonoff GB, Koval KJ, Skovron ML, Zuckerman JD: Hip fractures in the elderly: Predictors of one year mortality. J Orthop Trauma 1997;11:162-165

Principles of Fx Management

• The principles of biologic fracture repair should be applied whenever possible:– Careful handling of the soft tissue.– Avoiding unnecessary stripping.–Minimizing exposure of fracture site.– Preservation of fracture hematoma.

Principles of Fx Management

• Decline in capacity of fracture repair is age related.*

• Disturbance of the development of strength within fracture callus:

*Silver JJ, Einhorn TA: Osteoporosis and aging: Current update. Clin Orthop 1995;316:10-20

Problems in Fx Management

• Bone failure NOT implant breakage.

• Bone mineral density correlates with holding power of screws.

• Osteoporotic bone lacks the strength to hold screw / plate securely. *

• Loosening of the screw & implant.

* Sjostedt A, Zetterberg C, Hansson T, Hult E, Ekstrom L: Bone mineral content and fixation strength of femoral neck fractures: A cadaver study. Acta Orthop Scand 1994;65:161-165

Solution for Fx Management

• Traditional internal fixation techniques must be modified.

• IF devices that allow load sharing is used to minimize stress at the bone-implant interface.– Sliding nail plate devices, – intramedullary nails, – antiglides plates, and – tension band constructs BETTER than more rigid techniques.

Implant Fixation

• Screws • Plates• Intramedullary nails• Tension band wiring• Augmentation

ScrewsResistance to

pullout depends on:• Length of the screw• Thread diameter• Quality of the bone

– Density – Trabecular orientation

• Direction of insertion*– Parallel BETTER than

perpendicular to the trabecular pattern.

*An YH, Young FA, Kang Q, Williams KR: Effects of cancellous bone structure on screw pullout strength. Medical University of South Carolina Orthopedic Journal 2000;3:22-26

Screws• Bone quality prime determinant of

screw holding.• When bone mineral content falls

below 0.4 gram/cm2, the effect of varying thread diameter is lost.*

• To prevent loosening:– Place it as parralel as possible.– Use the largest thread diameter

compatible with the fracture scale.*Turner IG, Rice GN: Comparison of bone screw holding strength in healthy bovine and osteoporotic human cancellous bone. Clin Mater 1992;9:105-107

Screws

• In cases of severe osteoporosis screw fixation may be augmented with Polymethylmethacrylate (PMMA).*

• (1)Once the cement components are mixed (2)injected into the stripped screw holes (3)place the screw but incompletely tightened (4)after the cement has set (5)the screw is fully tightened.

*Motzkin NE, Chao EYS, An K-N, Wikenheiser MA, Lewallen DG: Pullout strength of screws from polymethylmethacrylate cement. J Bone Joint Surg Br 1994;76:320-323

Plates• The strength of plate fixation is affected

by the degree of comminution & the resulting size of any gap at fracture site.

• The most important factor reducing strain in plated fracture is cortical contact.

• Screw spacing is more important than the number of screws used for fixation.**Törnkvist H, Hearn TC, Schatzker J: The strength of plate fixation in relation to the number and spacing of bone screws. J Orthop Trauma 1996;10:204-208

Plates • Ellis et al * concluded: three screws

should be placed adjacent in either side of fracture gap.

• Cortical contact at the fracture site is paramount.

• In certain conditions (e.g. moderate comminution) the fracture should be shortened to achieve contact. *** Ellis T, Bourgeault CA, Kyle RF: Screw position affects dynamic compression plate strain in an in vitro fracture model. J Orthop Trauma 2001;15:333-337** Blatter G, König H, Janssen M, Magerl F: Primary femoral shortening osteosynthesis in the management of comminuted supracondylar femoral fractures. Arch Orthop Trauma Surg 1994;113:134-137

Plates

• Plates act as tension band NOT as bridge.

• When comminution is extensive consider double-plating.

• In oblique or spiral plates act as antiglide.

Intramedullary nails• Treatment of choice for diaphyseal

fractures in osteoporotic bone (femur & tibia). *

• The advantages of nailing: **

– Providing broad area of purchase.– Allowing load sharing.– Sufficiently secure fixation to allow

immediate weight bearing.

* McConnell T, Court-Brown C, Sarmiento A: Isolated tibial shaft fracture. J Orthop Trauma 2000;14:306-308** Rodriguez Alvarez J, Casteleiro Gonzolez R, Laguna Aranda R, Ferrer Blanco M, Cuervo Dehesa M: Indications for use of the long Gamma nail. Clin Orthop 1998;350:62-66

Intramedullary nails• IM positioned closer to mechanical axis

smaller bending forces than plate (external surface).

• Less fatigue failure compared with plate.• Greater strength in axial loading but less

stable during bending & torsion. *• Better suited for fixation of severely

comminuted osteoporotic bone fracture.

* Ito K, Grass R, Zwipp H: Internal fixation of supracondylar femoral fractures:Comparative biomechanical performance of the 95-degree blade plate and two retrograde nails. J Orthop Trauma 1998;12:259-266

Intramedullary nails• Major weakness of interlocking medullary

nails loosening of locking screws.• It is likely in distal femur rotational

fragment varus / valgus deformity.• Locking screw fixation can be improved:– By using different planes of screw orientation

(anteroposterior & transverse placement).– By using cement.

Tension band wiring

• TBW is usually applied to transverse fractures, which are distracted.

• It provides strong & secure fixation early mobilization of involved joint.

• Fractures: patella, olecranon, medial malleolus, proximal humerus.

Augmentation

• Bone grafting– Autograft: iliac crest (most common).– Allograft: allograft bone, demineralized

allograft bone, synthetic osteoconductive materials. *

• Bone cement– PMMA (polymethylmetacrylate)– Calcium phosphate.

* Gazdag AR, Lane JM, Glaser D, Forster RA: Alternatives to autogenous bone graft: Efficacy and indications. J Am Acad Orthop Surg 1995;3:1-8

Augmentation

Bone autograft (using cancellous bone)• (+)

– Cancellous bone can encourage rapid fracture healing osteoinductive, osteoconductive, osteogenic. 30

– Osteoporotic bone is NOT an inferior graft material.

• (-)– There is morbidity associated with the harvest of

autogenous bone.– Requiring larger exposure to get more bone graft.

Bone Cement• PMAA (Polymethylmethacrylate)

– Replacement of severely comminuted areas.– Successfully used in femur supracondylar fx &

intertrochanteric fx.– But, it is NOT ideal material permanent, foreign body,

generating heat. – Can be used to augment screw fixation.

• Calcium phosphate– Adhere better to bone.– Capable of being resorbed & replaced by host bone.– Successfully used in intertrochanteric fx & distal radius fx.– Used to fill the voids, not for augmentation of screw

fixation.

Fracture Types• Intertrochanteric fractures• Supracondyler fractures of the distal

femur• Lateral tibial plateu fractures• Ankle fractures & the distal fibula• Proximal humerus fractures

Intertrochanteric fractures

Supracondyler Fx of distal femur

Lateral tibial plateu fx

Ankle fx & Distal fibula

Proximal humerus fx

Postoperative Care

• Physical rehabilitation & psychososial treatment.• Preinjury functional compromise + additional disability

associated with recovery + depression/hopelessness multidisciplinary service.

• Malnourished state Clinical evaluation of nutritional status.

• Any patient past middle age with low-energy metaphyseal fx:– Undergo BMD testing– Placed on regiment to combat further bone loss.

• Calcium 1000-1500 mg/day• Vitamin D• Biphosphonate therapy

THANK YOUfor your attention