Traumatic Fractures: Problems And Solutions

From the Orthopedic Trauma Conference, presented by Cedars-Sinai Medical Center

Educational Objectives

The goal of this program is to improve management of traumatic fractures. After hearing and assimilating this program, the clinician will be better able to:

1.   Identify confounding factors that affect outcomes in fracture surgery.

2.   Describe the goals of initial and revision surgery for fractures.

3.   Classify types of failed fracture surgery.

4.   Avoid extensive stress shielding of host bone in managing periprosthetic hip fractures.

5.   Classify and manage periprosthetic knee fractures.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the plan­ning committee to disclose relevant financial relationships within the past 12 months that might create any personal con­flicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the following has been disclosed: Dr. Moon has been a consultant to Stryker Orthopaedics and Zimmer. Dr. Wiss, Dr. Solberg, and the planning committee reported nothing to disclose. In his lecture, Dr. Solberg presents information that is related to the off-label or investigational use of a therapy, product, or device

Acknowledgments

Drs. Wiss, Solberg, and Moon were recorded at Orthopedic Trauma Conference, which was presented in Los Angeles, CA, on May 9, 2009, by Cedars-Sinai Medical Center. The Audio-Digest Foundation thanks the speakers and Cedars-Sinai Medical Center for their cooperation in the production of this program.

Fractures Gone Wrong: Why Initial Management is so Important

Donald A. Wiss, MD, Orthopaedic Surgeon, Cedars-Sinai Orthopaedic Center, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA

Introduction: confounding factors in fracture fixation include obesity, smoking, poor nutrition, and use of corticoste­roids; failed internal fixation not uncommon; revision surgery often necessary; prognosis often worse with increased surgeries; however, failed fixation may not require surgery

Goals of fracture surgery: maintain adequate reduction throughout healing process; promote fracture healing through placement of implant; achieve stable internal fixation (not rigid fixation) to permit earlier recovery of range of motion and rehabilitation

Challenges in fracture surgery: surgical techniques difficult and challenging (long learning curve); pearl  —  key to fracture management is fracture reduction

Preoperative planning: any implant can break if fracture does not heal in timely fashion; time to healing depends on eg, type of implant, location of fracture; revision surgery usually elective (few emergencies); understand biome­chanics; remember “5 Ps” (perfect planning prevents poor performance)

Perioperative factors: controllable  —  method of fixation; type of implant; surgical technique; postoperative care; uncontrollable  —  bone quality; fracture location; type of fracture; status of soft tissue

Etiologies of treatment failure

Surgeon error: each case unique; challenges greater in revision surgery than initial surgery

Mechanical failure: causes  —  wrong implant, location, or size; technical errors; principles of successful treatment  —  careful soft-tissue handling; good reduction; stable internal fixation; wrong-sized implant  —  becoming more common because more surgeons using locked plates (affixes screw firmly to plate, but does not necessarily improve fracture bi­ology); technical errors  —  preventable; eg, poor reductions, fractures fixed in distraction, failure to compress stable fracture, failure to apply lag screws

Biologic failure: soft tissue stripping (case)  —  patient had mid-third femur fracture above total knee arthroplasty; treated postfailure with placement of antegrade nail and removal of broken hardware; impaired vascularity (case)  —  closed displaced distal tibial fracture; 12-cm incision; open nailing damaged periosteal and intramedullary blood supply to fracture (caused hypertrophic nonunion); treated by stable internal fixation with interfragmentary screw and neutralization plate (no bone graft); at 1 yr, bone solidly united

Classification of fracture failures

Potential criteria: early vs late (not very helpful); observation vs revision; type of implant; septic vs nonseptic (useful)

Rosen classification: right operation, wrong implant (case)  —nail used for displaced tibia; cerclage cable choking blood sup­ply at fracture site; wrong or unnecessary operation (case)  —  2-part fracture of proximal humerus due to isolated low-energy fall; after surgery, patient developed nonunion and stiff shoulder from Rush rod; sling and early range-of-motion therapy better options

How did fixation fail? pullout or breakage of screw; broken plate; cyclic loading; cantilever bending

When did it fail?

Early (ie, <6 wk postoperatively): case  —  skiing injury; inadequate unbalanced fixation (only 2 screws in metaphy­sis); questionable implant selection; treatment  —  fracture reduction without soft tissue stripping; different plate applied; articulated compression-distraction device fixed proximally; fracture pulled from varus into valgus; bal­anced fixation achieved with space screws

Intermediate failures (6 wk-6 mo): many due to combined mechanical and biologic failures; patients present with pro­gressive deformity leading to failure (dramatic change detected after series of x-rays); modern percutaneous tech­niques cannot substitute for well-planned carefully executed surgery

Late failures (>6 mo): nonunion protocols apply; typically, mechanical and biologic failure present; suspect infection; may relate to implant selection; case  —  ipsilateral fracture of humerus and forearm; fixation failing; after revision with allograft, patient developed radial nerve palsy; solution  —  dead allograft removed; using posterior approach, speaker cut cables, applied new bone graft, and loaded fracture using low-contact dynamic compression (LCDC) plate; at 4 mo, fracture nonunion site starting to heal; pearl  —  fracture site has potential to differentiate into bone in setting of stable fixation and good blood supply

Where did it fail? fewer weight-bearing considerations in upper extremity fractures than lower extremity fractures

What failed? main implant or ancillary support (eg, locking or syndesmotic screws); case  —  nonunion and failed fix­ation; bent nail present; deformity correction  —  3-point bend with hands and knee; closed exchange nailing without opening fracture site

Why did it fail? bone quality (less critical with use of locked plates); wrong implant type, size, or location; technical errors (eg, use of nonlag screw in fracture site); occasionally, poor patient compliance; case  —  teacher fell off step stool; tibial plate used to repair fracture in proximal humerus; at 9 mo, failure and nonunion; locked plate applied; 16 mo later, patient presents with painful shoulder; because head still viable, speaker elected to perform revision in­volving complex hardware removal with deformity correction (combined application of iliac crest bone graft and recombinant osteogenic protein [OP-1]); range of motion not perfect, but arm functional and patient happy

Conclusions: “there are no good or bad fractures” (only good or bad fracture care); surgeon must understand me­chanics and biology of fracture care; case  —  retired nurse presented with broken femur; patient history of osteo­genesis imperfecta overlooked; take-home points  —  vascularity is biologic basis and stability is mechanical basis for uncomplicated fracture healing; master reduction techniques; individualize treatments; be suspicious of failed fixation; obtain appropriate cultures; surgical revision after multiple failures particularly challenging; speaker grafts liberally; thorough preoperative planning, indirect reduction, and stable fixation usually effective

Periprosthetic Hip Fractures

Brian Solberg, MD, Orthopaedic Surgeon, Orthopaedic Trauma and Fracture Specialist, Los Angeles, CA

Introduction: incidence of insufficiency fracture 2% to 3% at 15 yr after total hip arthroplasty (THA; £1% iatro­genic; incidence 8%-20% after revision surgery); treatment hampered by 1) high infection rates and 2) loosening, failure, or refracture (rates as high as 20%); prevention possible

Problems in older patients include: poor bone quality; femoral stem locks proximal femoral fixation; no endosteal blood supply present if stem cemented; cable fixation alone inadequate in many cases

Classification of periprosthetic femur fractures

Fracture types: 1) osteolysis with pathologic fracture; 2) high-energy trauma; 3) fracture caused by stem failure

Vancouver classification

Type A fractures: greater trochanteric fractures  —  may not require surgery, but observation indicated; if frag­ment migrates >1.0 cm, fix with cable (usually, with bone graft); lesser trochanteric fractures  —  generally need surgical intervention; otherwise, stem will tilt into varus and fail

Type B fractures: occur in conjunction with stem; B1 (stable implant); B2 (loose implant); B3 (fracture in associ­ation with stem, plus associated bone loss)

Type C fractures: occur distal to stem (femoral shaft fractures in conjunction with stem, but higher up)

General management principles: first, do no harm; mobilize patients as quickly as possible; if stem loose  —  replacement probably necessary; may need to extend stem distally to achieve better intramedullary fixation; if stem stable  —  relative stability principles apply; need extramedullary fixation involving plate, cables, screws

“Relative stability” defined: stability allowing physiologic movement of limb without rigid fixation; secondary healing occurs with callus formation; avoid screws around proximal part of implant or in cement (can lead to fracture; use cer­clage wires in those areas where screws contraindicated)

Biomechanical principles: allograft struts  —  have received “bad rap” in fracture community; act as “biologic plates”; even though cadaveric bone used, elasticity similar to cortical bone (assuming no bone loss); advantage (prevents extensive stress shielding of host bone seen with locked implants); plates with distal screws and proximal cables  —biomechanically better than allograft struts and cables alone (need screw fixation proximally and distally); combination of alternating cerclage cables and locking unicortical screws most biomechanically sound construct; locked screws advantageous, especially in osteoparietal bone; stability of constructs  —  locked screws most stable, followed by unlocked screws, then by wires and cerclage cables; plates more rigid and stable than allograft struts; must balance biologic cost of using implants with mechanical benefit; with many periprosthetic fractures, must splint almost entire bone (failure to do so risks catastrophic failure later); use screws where possible, and maintain fracture environment that promotes healing

Vancouver classification revisited

Type A fractures: undisplaced fracture of greater trochanter  —follow weekly for first 3 wk, then every other week; dis­placed fracture  —  consider bone grafting; displacements that occur in THA have high risk for dislocation, especially if they migrate

Type B fractures: case  —  man with stable stem; some hardware already in place; want relative stability, but fairly long construct; use cables where necessary, screw fixation distally, and longer construct; case  —  elderly patient; American Society of Anesethsiologists (ASA) physical status category 4 (has severe systemic disease that is constant threat to life); addressing mechanical issues on medial side especially important with weak and osteoporotic bone; type B2 (implant loose)  —  goal relative stability; if stem unstable, replace it; measure length of stem, bypass whole area, and reconstruct tube; splint bone distally; managing long extension fractures distal to stem  —  consider use of intracortical screws; avoid screws that traverse from cortex to cortex without entering intramedullary cavity; 2.0-mm or 2.4-mm diameter screws helpful to provide provisional fixation that does not interfere with ability to put larger stem down; re­construct tube in conjunction with interference fit; need fairly large, long cable combination plates; allograft often needed if bone stock deficient or for proximal reconstruction if osteolysis present

Type C fractures: occur distal to stem (often posteriorly, in conjunction with arthroplasty); associated with osteopo­rotic bone; status of hip affects fixation options; most locking screw plates allow placement of cables and plates superiorly, and stem distally

Disaster cases: surgeon did not run cables high enough on femur; lack of adequate fixation led to failure; stem well-fixed, but large angular deformity and hypertrophic nonunion present; revision surgery  —  nonlocking implant worked fairly well; unicortical screws used superiorly; fractures that defy Vancouver classification  —  trochanteric involvement, loose stem, and extension to metadiaphyseal flare of distal femur; in intramedullary fixation, make sure stem long enough; if stem not large enough, it rotates and becomes dislocated (need good intramedullary and extramedullary fixation)

Summary: consider patient factors and balance early morbidity with effect of major surgery; if stem loose, exchange it in favor of long intramedullary fixation; many patients require augmentation with extramedullary fixation; best biomechanical results achieved by using hybrid plates that have unicortical lock screws and cables around upper part of implant, then locking screws distally; in extramedullary fixation, many patients need long construct that spans entire length of femur

Periprosthetic Knee Fractures

Charles N. Moon, MD, Associate Director, Orthopaedic Trauma Services, Cedars-Sinai Orthopaedic Center, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA

Epidemiology: 6-fold increase predicted in demand for total knee arthroplasty (TKA) by year 2030 (therefore, poten­tial 6-fold increase in periprosthetic fractures); problem most common in patients >60 yr of age (most commonly due to low-energy fall); morbidity and mortality worrisome

Classification of fractures after TKA: type 1 (proximal to flange); type 2 (extends to flange); type 3 (past flange)

Type 1 fractures: straightforward (relatively easy to treat); for open box implant, retrograde nails work well (if un­certain whether open or closed, consider open reduction, internal fixation (ORIF); case  —  if bone osteoporotic and cortices compromised, get ³2 cortical diameters past junction to avoid stress riser effect

Type 2 fractures: use of retrograde nails with implant one option; tendency for flexion/extension problem and an­teroposterior displacement; often, boxes not in line with shaft; fixed-angle device probably best choice (eg, fem­oral plate, delayed plate, or dynamic condylar screw [DCS] plate); caveat concerning use of retrograde nails  —  box not in line with shaft (retrograde nails tend to line up with shaft); result extension deformity or anterior/pos­terior displacement (best to reduce); study  —  use of tibial nails instead of retrograde femoral nails avoided prob­lem of anteroposterior displacement or extension deformity

Type 3 fractures: implant distal to flange often not stable (not much bone available) and needs revision; may not have enough bone for standard revision (consider distal femoral replacement); if not comfortable revising type 3 fracture, consider referral; case  —  92-yr-old woman with severe rheumatoid arthritis; cemented THA above type 3 fracture with TKA; patient not healthy (cardiologist reluctant to have patient undergo surgery); fracture clearly below flange; to revise, need stemmed implant; pulled out to length, reduction easy; cast risks skin problem; no femur to nail; speaker’s approach  —  polyaxial locking plate; screws aimed into corner where bone more abun­dant; at 6 wk postoperatively, repair holding together and shows evidence of healing

Suggested Reading

Boraiah S et al: Outcome following open reduction and internal fixation of open pilon fractures. J Bone Joint Surg Am 92:346, 2010; Corten K et al: An algorithm for the surgical treatment of periprosthetic fractures of the femur around a well-fixed femoral compo­nent. J Bone Joint Surg Br 91:1424, 2009; Otto RJ et al: Biomechanical comparison of polyaxial-type locking plates and a fixed-an­gle locking plate for internal fixation of distal femur fractures. J Orthop Trauma 23:645, 2009; Parvizi J et al: Periprosthetic knee fractures. J Orthop Trauma 22:663, 2008; Perry JJ et al: Managing bone deficiency and nonunions of the proximal femur. Orthop Clin North Am 41:105, 2010; Pike J et al: Principles of treatment for periprosthetic femoral shaft fractures around a well-fixed total hip arthroplasty. J Am Acad Orthop Surg 17:677, 2009; Van Flandern GJ: Periprosthetic fractures in total hip arthroplasty. Orthope­dics 28:s1089, 2005; Zustin J, Winter, E: Failed internal fixation due to osteonecrosis following periprosthetic fracture after hip re­surfacing arthroplasty. Acta Orthop 80:666, 2009.