A prospective study of a titanium femoral component for cemented total hip arthroplasty

The Journal of Arthroplasty Vol . 9 No . 6 1994

A Prospective Study of a Titanium Femoral Component for Cemented Total Hip Arthroplasty Geoffrey S . Tompkins, MD, Paul F. Lachicwicz, MD, and Ralph DeMasi, MPH

Abstract : The authors studied the clinical and radiographic results of a modern titanium-alloy femoral stern with a cobalt-chrome-alloy head for use in cemented total trip arthroplasty . One hundred sixteen hips (102 patients) were operated on using modern cement techniques and prospectively followed using the Hospital for Special Surgery hip rating system and standard radiographic criteria . At a mean follow-up period of 4 .8 years (range, 2-8 years), 69 hips were rated excellent, 38 good, 4 fait, and 5 poor . A total of 13 Icmoral components (11%) were radiographically loose according to the criteria of Harris . In 1 I of these loose femoral components, debonding or separation at the cement-prosthesis interface, was the initial cause of failure, with bone-cement interface erosions occurring later in five hips . Revision of a loose femoral component has been performed in three hips and is pending in two other hips (4 .30/,,) . Significant calcar resorption was seen in only 1 7 hips (116'%), and serial measurements of distal femoral cortical widths showed no distal cortical hypertrophy except in one femur . The incidence of loosening with this cemented titanium-alloy femoral component (with a cobalt-chrome-alloy head) is much higher than published reports of similar cobalt-chrome-alloy stems . The authors have abandoned the use of titaniumalloy femoral components for cemented total hip arthroplasty . Key words : titanium alloy femoral component, cemented femoral component, cemented total hip arth roplasty .

vcrsial, and the optimal alloy for the THA femoral component remains unknown . In July 1983, the senior author (P . 1- . L .) began a prospective study of a cemented, titanium-alloy femoral stem, with a cobalt-chrome-alloy head for use in THA (Fig . 1) . The Triad (Johnson & Johnson, New Brunswick, NJ) total hip prosthesis was utilized for all primary, conversion, and revision cemented THAs during a 5 h-,,-year period . The Triad femoral component was designed to reduce stem stress through proximal bone loading . In addition, it was intended to reproduce the patient's normal hip anatomy more accurately by offering a large selection of stem sizes, neck lengths, and offsets, The purpose of this study is to report the clinical and radiographic results of thts unique prosthesis, with particular attention to radiographic loosening, as well as calcar resorption, cortical hypertrophy, and development of radiolucenl lines .

Cemented total hip arthroplasty (Tl1A) is one of the most frequently performed orthopedic surgical procedures . Although much current attention is focused on cemcntless bone-ingrowth arthroplasty, the need for cemented arthroplasty, particularly among osteoporotic and elderly patients, is likely to continue . Loosening of the prosthesis, particularly the femoral component, remains a significant long-term problem with cemented THA . Numerous factors have been implicated in early loosening, including the sex of the patient, body weight, activity level, surgeon's experience, and prosthetic design . Of these, prosthetic design is currently the most contro-

Car'etinaa

Frc n the Ptt'tsiml of 0rthopaedii .Surgery, The Onivrn,iv d/ Nortb chapel Fill, Nari1r ca, etina . Reprint requests : Paul F . Lachicwicz, MD, Division of Orthopae-

die Surgery, The university of North Carolina, 250 pernelt-Womack Building, _2 29-It . Chapel Hill, NC 27599-7055 .

623

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The Journal of Arthroplasty Vol . 9 No . 6 December 1994

Fig . 1 . The titanium-alloy stem, cobalt-chrome-alloy, 28 mm head femoral component (Triad) .

Materials and Methods Between July 1983 and February 1989, 142 cemented THAs utilizing the Triad femoral component were implanted in 126 patients . Sixteen hips in 14 patients who had died arid 3 hips in 3 patients who were lost during the follow-up period were excluded from analysis . In one hip (I patient), there was a late deep infection at 1 year that required component removal . This patient was excluded from analysis . Six hips (6 patients) were revisions of failed cemented femoral components and were excluded . Thus, 116 hips (102 patients) completed a minimum 2-year follow-up period and were studied in detailAll hips were functioning well in the patients that (lied or were lost . One hundred six hips were primary THAs and 10 were conversion arthroplasties (from noncemented henuarthroplasty) . Thirty-six hips were placed in men and 80 were placed in women . The mean patient age was 63 years (range, 18-88 years) and the mean weight was 73 kg (range, 38-118 kg) . The preoperative diagnoses were osteoarthritis in 70 patients, rheumatoid arthritis in 18, avascular necrosis in I I, failed noncemented hemiarthroplasty in 10, nonunion of femoral neck fracture in 6, and non-

union of an acetabular fracture in 1 . The mean follow-up period was 57 .6 Months (range . 24-96 months) . All surgeries were performed by or under the direction of the senior author in a standard operating room without laminar air flow . The mean operating time was 208 minutes, and the mean blood loss was 1,340 mL . The Triad femoral component has a smooth neck, collar, and stem made from a single piece of Ti6AI4V alloy bonded to a 28 mm diameter cobalt-chromealloy head . Stern sizes are available in 13 .0, 14 .5, 16 .0, and 175 mm ; neck lengths are low, medium, and high ; and offsets are 40 and 45 nun . All hips were templated before surgery with the center of rotation of the prosthetic head at the center of rotation of the normal femoral head . The stem was designed to fill 80% of the femoral canal . To facilitate this, specific conical hand reamers and rasps (broaches) corresponding to the stern sizes are provided . However, the conical-shaped reamers were not used in this series, as the senior author believed that these reamers removed excessive proximal bone . A polyethylene cement restrictor (Buck, Smith fr Nephew Richards, Memphis, TN) was placed at least I cm distal to the tip of the stem, unless a satisfactory boric plug already existed . The femoral canal was irrigated with pulsatile lavage, dried, and packed with gauze . Simplex P polyrnethyl methacrylate bone-cement (Howmedica, Rutherford, NJ) was injected using a cenrcut gun and manually pressurized several times using a rubber dam . Radiographs were obtained in (he recovery room, and at 6 weeks, 6 months, I year, and yearly thereafter. Occasionally this routine was not possible . Because recovery room radiographs were taken with portable equipment, their overall quality and magnification differed from the routine outpatient radiographs and were therefore nor evaluated in this study . The 6-week postoperative radiograph obtained in the hospital radiology suite was the initial one considered . Each patient was interviewed, examined, and assigned pre- and postoperative clinical ratings by the senior author . A modified Hospital for Special Surgery hip rating scale was used .' Ten points cacti were allotted for pain, ambulalion, motion-muscle power, and function . A total score of 32 points OF more arid a pain rating of 8 points or more was considered an excellent result . The modification precluded rating a hip with a score of 32 points or more as excellent if the pain rating was less than 8 points . A total score of 24- 31 points and a pain rating of 6 points or more was considered a good result ; 16-23 pointy ora pair score of 4-5 points was a lair result ; less than 15

The Journal of Arthroplasty Vol . 9 No . 6 1994 638

Titanium Femoral Components Tompkins et The Journal of Arthroplasty Vol Hydroxyapatite-augmented . 9 No . 6 December 1994 and Nonaugmented THA •e Ciccotti et al al. .

625 6 33

Table fem1 . Variables Studiedin human THA and that earlier unprotected unprotected weight-bearing does not jeopardize gration oral fixation . Patient Data weight bearing does Data not jeopardize femoral implant Radiographic The parameters traditionally used to assess prosfixation, regardless of coating design . The initially

Heterotopic Ossification Alignment : neutral, yams, valgus Following Uncemented Total Hip Arthroplasty Heterotopic weight that has heretofore been lacking of precision . Ac- ossification more of a reflection of bony ingrowth than true miAg

thetic implant fixation have remained, in large part, incidence of visual analog thigh pain with the Stem-canal fill ((%)lower : anteroposterior and lateral Sex rudimentary degreereconstruction hydroxyapatite-augmented stems, however, may be Height . The RSA, however, provides aAnatomic

Diagnosis Calcar resorption (significant if - 3 mm) gration and as such, adds some validity to the theoHospital for Special surgery hip score Subsidence (date seen) Effect thelin-Operative Approach RSA Stein havesize been determined as 0 .05-0 .1of mm Radiolucencies for retic advantages of .enhanced-surface prostheses . (stern-cement, bone-cement date recognized'widthtzone) Offset size and 0 .2° for rotation . In 1980, Cement fractures (location, date recognized) ear translation BaldWhile a plethora of literature exists attesting to the Neck length Femoral cortical nidlh Iproximal, rnidstern, distal stein) ursson et al ."' evaluated acetabular prosthetic migraadvantages of hydroxyapatite in the animal hip CmnpricaIion' Cement technique (I)orr criteria) tion in four patients with rheumatoid arthritis using model, few reports describe the effects of such surLeg-length difference Robert Bischoff, MD,* James Dunlap, MD,* Lawrence Carpenter, BS,* the RSA technique over a 24-month period . Revision No clini-(date performed) faces on human hip implants . This study utilizes the cording to the initial studies of Selvik, 10 the limits of

Edward DeMouy, MD,t and RSA Robert Barrack, MD* technique to better define

cal or plain radiographic signs of loosening were

the role of enhanced surfaces in human THA . The long-tern implications of these initial findings, however, await further clinical, plain and radiographic, and RSA follow-up probable, definite component looseningevaluwere ation . determined using the criteria of Harris and McGann . 4

noted, while all patients demonstrated gradual acetabular migration up to 1 .8 mm and rotation up to

5 .5° with Translation and rotation greatpoints or aRSA pain. rating of 3 points or less were was considest inpoor the. initial months after THA. M,joberg et al .,` ered inPatient 1986, and Snorrason and Karrholin," in of 1990, charts Abstract: and radiographs A consecutive were series reviewed 112 by primary Theuncemented corticaltotal width hipofarthroplasties the femur was measured in using the same type of prosthesis was reviewed for the incidence and of (Fig . 2) on each usedauthor the RSA technique to evaluate cemented and one (G . S T . . .) Variables studied are shown three medial and lateral severity locations Fig . 2 . Tantalum spheres measuring 0 .8 mm in diameter . References heterotopic ossification (HO) . Sixty-three of these patients underwent a posterior apuncentented THA . Their studies detected component in Table 1 . All data were entered and stored on an postoperative radiograph . technique The ratios. of the final Fig . 3 . Lesser trochanteric Spheres werefolimproach (group 1) and 49 underwent an anterolateral approach 2) .femoral The twocanal through migration in 35-50% of implants within 4-12 IBM PS2 computer (International Business Malow-up to (group the initial postoperative widths plantedwidths from the broached the groups were virtually identical risk factors, such as age, sex, estimated blood months after THA . These investigators identified RSA calcar 1 . Charnley . J : .Anchorage of thefill femoral prosthesis chines, Armonk, NY) using the Data Ease (Datawhen Ease were calculated Stern canal was head determined on loss, lengthforof detection surgery, and diagnosis were comparedto. the Patients in group 1 had a signifias the most precise methodCO) of prosthetic shaft of the femur . radiographs J Bone JointasSurg 428 :28, International, Trumble, database. The data were anteroposterior and lateral described All procedures were carried using and theseverity same surgicantly lower out incidence of HO than those1960 in group 2 . The overall incidence migration and, indirectly, fixation .Analysis Their findings then transferred the Statistical System Robinsonthat et uncemented al .' Leg-length discrepancies were cal technique byofto orclass under the direct supervision III or IV 110 was very lowof(8%), by indicating total hip 2 . Amstutz HC, Markolf Kl ., McNeice (,M et al Loosensuggest that this technique allowspackage more significant (SAS Institute Cary, NC) software forstatiscalculated by measuring the distances front the: lesser in itself is not predisposed to moderate orof severe of trochanteric HO . Patients the investigators arthroplasty . planted into thedegrees greater bed through the ing total hip components : cause and prevention interpretation of early follow-up data was for THA . Our analysis Irochanters to pelvic bony landmarks . Cement tech- . tical analysis undergoing total hip2)arthroplasty through an anterolateral approach had tantalum uncemented spheres (Fig .performed were Eight 0 .8 .mmSurvivorship cut surface (Fig . 4) . p . 102 . In the Flip : proceedings of the Fourth Open stereoradiographic data corroborate these results as using methoda of Armitage with failure defined wassurgery, considered iftreated the criteria dehigher incidence of 110 than those undergoing anique posterior approach in satisfactory this series . Society, Key placed the periprosthetically at the time of THA using a After all patients were intraScientific Meeting of the Flip CVwith Mosby . St . some degree of linear migration was detected in all as radiographic evidence : of hip, definite arthroplasty, loosening uncemented, of the heterotopic scribed ossification, by Dorr et operative al .' were approach met . This . requires that words hand-held implanter as described by Aronson et al ." Louis, 1976 venous antibiotics for 48 hours and received warfarin groups within 1 year of THA . These findings were component . of there be(Coumadin, a complete, intact mantle adjacent 3 . Beckenbaugh RD .DuPont, [[sit up cement DM : Total hip arthropiasly On completion the femoral broaching, but before sodium Wilmington, DE) as a: not reflected in our Charnley or plain radiographic to each femoral component. There must he a minia review of three hundred and thirty-three eases with insertion of the actual stem, three of the spheres were routine thromboembolic prophylaxis . All patients results, thereby implying that RSA may provide the mum of 3 mm of cement in the proximomedial third lung hullow-up . J Bone Joint Surg 6UA :306, 1978 Radiographic Review implanted via the canal through the calcar into the were enrolled in a standardized rehabilitation promost precise assessment of early implant migration . and mm accordance in the lateral third, andweight-bearcement had: 4 . 3Pilliar RM, distal Welsh RI), MacNab I : Surgical implants lesser trochanteric region (Fig . 3) . After the trochangram in with their specific Heterotopic (HO) haspossible reported to on the of HO porosity following strictly uncemented Measurements were made, using abeen hand-held Obtaining the ossification theoretic precision with mithe the incidence role of surface inthe fixation to bone and to extend at least I cmn distal to tip of the femoral ing has status beginning on the. first postoperative day . teric wires beencommon placedcomplications and the femoral prosbe onetechnique, of from thehadmost following THA be reported The of this study acrylic crometer, anteroposterior radiographs of time the RSA however, requires significant . JtoBone Joint Surg 53A purpose :9o3, 1971 stern . yet thesis inserted, the remaining five spheres were imClinical and plain radiographic evaluations were oba total hip (THA) .toWhereas the is5 .to(,alante report.1, theRostoker incidence and severity of HO in W, Lucck R et al : Sintered fiber pelvis andarthroplasty proximal femur extending distal toincidence the tip and extremely close attention detail, from imaging 1 .2 metal composites as a basis fur attachment of implants HO has varied from 5 to 90%, the presence of consecutive series of primary uncemented THA and of of prosthesis and fromeach frog-leg lateral radiothethe patient to digitizing stereoradiograph arid to bonethe . J effect Bone Joint Surgoperative 53A :101, approach 1971 determine of the (anaprocessing functionally significant amount of ectopic has theproximal data . graphs of the femur extending distalbone to the Results 6 . Jarcho M vs : Calcium phosphate ceramics as hardHOtissue terolateral posterior) on postoperative in a been found to range from I to 27% . 3 The etiology tipThis of the prosthesis Anatomic offset was considered evaluation of. hydroxvapatite-augiiietited arid prosthetics . Chinundergoing Orthop 157 :259 . 1981 THA using group of patients uncemented of this reproduced HO remains but predisto have ifunknown, theTHA offsetoffers of reported theseveral operated side nonaugmented porous suggesTechnical 7 . DcGroot K, DcPutter C . Silvans-Smut PAP : Transmuan anatomic stem with circumfe_rential porous posing factors include with osteoarthrosis, 4at7 (the .horizontal distancethose from the center of rotation tions Charnley evaluation and plain radiography cosal implants of dense hydroxyapatite . J Prosthet coating . hematoma formation," operative approach of thefollow-up femoral head to (lie line of significant the used,` femoral Ninety-eight femoral components were placed in early intervals docenter not show any Dent 49 :87, 1983 and those with diagnoses of ankylosing sponstem) was within 5 mm of thefemoral anatomic side .types Stern neutral alignment, 3 for in vans, and 15 system in valgus-The differences withthe the various implant 8 . Galante J : The need a standardized fur evaldylitis alignment and(neutral, diffuse idiopathic varus, valgus) skeletal was hyperostocollar wasresults placedofinside thesurgeryneck in(editorial) 16 hips and on or postoperative weight-bearing protocols .recorded This may. uating total hip J Bone Materials and Methods sis Heterotopic .' ossification It hydroxyapatite appears that was agraded mutifactorial using theetiology classifiis the Joint proximomedial neck in 100 hips . Only suggest that augmentation and 12 Surg 67A :51femoral I, 1985 Fig . .4. Greater trochanter 9 . Salvati Im VC, Aglictti P elmore al : Radiology of total likely cation of postoperative Brooker et at .' Calcarweight resorption wasdo mea12% of the EA, stems filled 80% or of the femoral weeks of partial bearing not technique . spheres were imhip replacements . Clio Orthop 121 :74, 1976 sured and the date of its appearance was recorded . medullary canal in either the anteroposterior or latprovide any discernable advantages . More probably, It has been recently suggested that the incidence Ninety-five patients who underwent 112: aprimary planted through the cut sur10. Selvik G : Roentgen srereophotogrammeriv method though, it indicates that clinical evaluation and plain Three and millimeters of HO or is greater higher following considered uncemented signifieral planes .THAs Femoral cement technique was study satisfacface severity after the stem and the tro- was uncemented included inttte this and. tot' the study ofwere the kinematics ofof skeletal system cant . Subsidence was measured and the date of its tory in 77% of the hips . In 87% the hips deemed radiography lack the precision required to reliably THA ." However, the effect of an operative approach chanteric wires had been reviewed in a retrospective Acta Orthop Scand Suppl 60 fashion :1 . 1989. The patients appearance recordedfixation . Subsidence than 3 unsatisfactory, the reason was the presence of less assess prosthetic . Thegreater stereoradioplaced . earlywas were dividedB,into two groups based the operative 11 . Mjoberg trancson LL Selvik G : on instability, nugramm was considered significant andprosthetic interpreted as than 3 mm of the cement mantle lateral to the distal graphic data most precisely reveal migration, and laxity of total hip prostheses : apatients roentgen sterapproach used . Group I consisted of 52 from tion inloosening all groups, but it should he notedradiolucent that migragross . Femoral component stemeophotogrammeiric . Eighty-nine of study the hips were 40 mm offset and hiam the Deparbrrervs of''Orlhopaedic .Surgery and tRadiclogv, Tu. Acta Orhop 55 : t41 . the US Naval Hospital (Oakland, CA)Scand who underlane lines University (stem-cement SdroeI of Medicine, and hone-cement) New Orleans. were. mea27 were 45 mm offset . Anatomic offset within 5 mm tion rates are unaltered by the Louisiana presence of 1984 went 63 noncemented THAs from 1987 to 1989 Reprint requests Dr . RobertofBarrack, Department of the Orthopacsured using the:augmentation method Gruen et al .,' and hydroxyapatite or earlier unprotected date was reproduced in 57 C,ofHansson 81 hipsLI(70%) which it 12 . Mjoberg B, Selvik al in : Mechanical dics-SL32, 1430 Tulane Avenue, New Orleans . LA 70112 . using the LSF hip system (Implant10et Technology, See. This suggests that enof their appearance recorded . The presence and could be assessed, within in Joint 70 of 77 postoperative weightwas hearing loosening of total and hip prostheses. Jmm Bone Surg locationsurfaces of cement recorded . Possible, hips68B_770, (91"/o) .1986 There were 92 low neck, 23 medium hanced do fractures not alter were femoral component mi-

641

The Journal of Arthroplasty Vol . 9 No . 6 1994 Titanium Femoral Components Tompkins et 626 638 The The Journal Journal of of Arthroplasty Arthroplasty Vol Vol Hydroxyapatite-augmented .. 99 NoNo.. 66 December December 1994 1994 and Nonaugmented THA •e Ciccotti et al al. . 625 6 33 Table fem1 . Variables ofgration 4Studied unprotected weight-bearing does not jeopardize .0 points in human to a postoperative THA and that 6 .6earlier points .unprotected Moderate oral fixation . Patient Data improvement weight bearing in does mean not ambulation jeopardize and femoral hip motion implant Radiographic Data The parameters traditionally used to assess prosscores was seen, increasing from 4 fixation, regardless of coating design .8 to 8..1The points initially and

Heterotopic Ossification Alignment : neutral, yams, valgus Following Uncemented Total Hip Arthroplasty Heterotopic weight that has heretofore been lacking of precision . Ac- ossification more of a reflection of bony ingrowth than true miAg

5 .5 to 8incidence thetic implant fixation have remained, in large part, .7 points,ofrespectively visual analog . Overall, thigh pain the patients with the Stem-canal fill ((%)lower : anteroposterior and lateral Sex rudimentary degreereconstruction seemed quite satisfied with their results hydroxyapatite-augmented stems, however, . may be Height . The RSA, however, provides aAnatomic

Diagnosis Calcar resorption Radiographic (significant if - 3 Results mm) gration and as such, adds some validity to the theoHospital for Special surgery hip score Subsidence (date seen) Effect thelin-Operative Approach RSA Stein havesize been determined as 0 .05-0 .1of mm Radiolucencies for retic advantages of .enhanced-surface prostheses . (stern-cement, bone-cement date recognized'widthtzone) There were no obvious cement fractures seen on Offset size and 0 .2° for rotation . In 1980, Cement fractures (location, date recognized) ear translation BaldWhile a plethora of literature exists attesting to the any radiograph . Two hips one patient with chronic Neck length Femoral cortical nidlh Iproximal, rnidstern, distalinstein) ursson et al ."' evaluated acetabular prosthetic migraadvantages of hydroxyapatite in the animal hip CmnpricaIion' Cement technique renal (I)orr criteria) failure and severe metabolic bone disease had tion in four patients with rheumatoid arthritis using difference model, few reports describe the effects of such surLeg-length Robert Bischoff, MD,* James Dunlap,complete MD,* Lawrence Carpenter, BS,* bone-cement radiolucent lines around the RSA technique over a 24-month period . Revision No clini-(date performed) faces on human hip implants . This study utilizes the both components and bilateral femoral subsidence at Edward DeMouy, MD,t and Robert Barrack, MD* cal or plain radiographic signs of loosening were RSA technique to better define the role of enhanced 3 years, which progressed at 5 years . The patient's noted, while all patients demonstrated gradual acesurfaces in human THA . The long-tern implications overall medical condition precluded revision . Five tabular migration up to 1 .8 mm and rotation up to of these initial findings, however, await further clinihips showed a femoral stem-cement radiolucenl line 5 .5° with Translation and rotation greatcal, plain and radiographic, and RSA follow-up evalupoints or aRSA pain. rating of 3 points or less were was considprobable, definite loosening (dehonding) in Gruen zone component 1 that progressed to were cysest inpoor the. initial months after THA. M,joberg et al .,` ation . ered determined using the criteria of Harris and McGann tic cortical erosion at the bone-cetnent interface in. 4 inPatient 1986, and Snorrason and Karrholin," in of 1990, charts Abstract: and radiographs A consecutive were series reviewed 112 by primary Theuncemented corticaltotal width hipofarthroplasties the femur was measured in the midfcmoral zones (Fig . 3) . Six femoral compousing the same type of prosthesis was reviewed for the incidence and of (Fig . 2) on each usedauthor the RSA technique to evaluate cemented and one (G . S T . . .) Variables studied are shown three medial lateral severity locations Fig . 2 . Tantalum spheres measuring 0 .8 mm in diameter . nents showedand isolated stem-cement radiolucenl References heterotopic ossification (HO) . Sixty-three of these patients underwent a posterior apuncentented THA . Their studies detected component in Table 1 . All data were entered and stored on an postoperative radiograph . technique The ratios.inof the final Fig . 3less . Lesser trochanteric Spheres werefolimlines than or equal to I runt Gruen zone 1proach (group 1) and 49 underwent an anterolateral approach 2) .femoral The twocanal through migration in 35-50% of implants within 4-12 IBM PS2 computer (International Business Malow-up widths to (group the initial postoperative widths planted from the broached the Thus, such a total of sex, 13 femoral components (11%) were groups were virtually identical risk factors, as age, estimated blood months after THA . These investigators identified RSA calcar 1 . Charnley . J : .Anchorage of thefill femoral head prosthesis chines, Armonk, NY) using the Data Ease (Datawhen Ease were calculated Stern canal was determined on judged to be definitely loose the criteria of Harris loss, lengthforof detection surgery, and diagnosis were compared . Patients in group 1 had by as the most precise methodCO) of prosthetic to the shaft of the femur .aradiographs JsignifiBone JointasSurg 428 :28, International, Trumble, database. The data were anteroposterior and lateral described All procedures were carried using and theseverity same surgiMcGann .'2 No femoral cantly lower out incidence of HO thanand those in group . The overall component incidence showed prob1960 migration and, indirectly, fixation .Analysis Their findings then transferred the Statistical System by Robinson et uncemented al .' Leg-length discrepancies were cal technique byofto orclass under the direct supervision or possible loosening III or IV 110 was very lowof(8%), able indicating that total hip . 2 . Amstutz HC, Markolf Kl ., McNeice (,M et al : lesser Loosensuggest that this technique allowspackage more significant (SAS Institute Cary, NC) software forstatiscalculated by measuring the distances front the in itself is not predisposed to moderate orof severe degrees of trochanteric HO . Patients the investigators arthroplasty . planted Theing six into hips the with greater isolated Gruen Zone bed I through stem-cethe total hip components : cause and prevention interpretation of early follow-up data was for THA . Our analysis Irochanters to pelvic bony landmarks . Cement tech- . tical analysis undergoing total hip2)arthroplasty through an anterolateral approach had tantalum uncemented spheres (Fig .performed were Eight 0 .8 .mmSurvivorship cut surface (Fig . 4) . ment radiolucent lines were rated as good or excelp . 102 . In the Flip : proceedings of the Fourth Open stereoradiographic data corroborate these results as using methoda of Armitage with failure defined considered if the criteria dehigher incidence of 110 than those undergoing anique posterior approach in satisfactory this series . Society, Key placed the periprosthetically at the time of THA using a After surgery, all patients were treated intralent Scientific atwas the mostMeeting recent offollow-up the Flip evaluation CVwith Mosby (range, . St . some degree of linear migration was detected in all as radiographic evidence : of hip, definite arthroplasty, loosening uncemented, of the heterotopic scribed ossification, by Dorr et operative al .' were approach met . This . requires that words hand-held implanter as described by Aronson et al ." Louis, 1976 . The 60-72 venous months) antibiotics for 48 seven hourships and received with femoral warfarin groups within 1 year of THA . These findings were component . of there be(Coumadin, a complete, intact mantle adjacent 3 . Beckenbaugh RD .DuPont, [[sit up cement DM : Total hip arthropiasly On completion the femoral broaching, but before sodium Wilmington, DE) as a: bone-cement erosions or radiolucent lines and/or not reflected in our Charnley or plain radiographic to each femoral component. There must he a minia review of three hundred and thirty-three eases with insertion of the actual stem, three of the spheres were femoral routinecomponent thromboembolic subsidenceprophylaxis had fair or. poor All patients cliniresults, thereby implying that RSA may provide the mum of 3 mm of cement in the proximomedial third lung hullow-up . J Bone Joint Surg 6UA :306, 1978 Radiographic Review implanted via the canal through the calcar into the cal were hipenrolled scores at in their a standardized most recentrehabilitation follow-up evaluapromost precise assessment of early implant migration . and mm accordance in the distal lateral third, andweight-bearcement had: 4 . 3Pilliar RM, Welsh RI), MacNab I : Surgical implants lesser trochanteric region (Fig . 3) . After the trochantion gram (range, in 24-60 with months) their specific . There were two addiHeterotopic (HO) haspossible reported to on the of HO porosity following strictly uncemented Measurements were made, using abeen hand-held Obtaining the ossification theoretic precision with mithe the incidence role of surface inthe fixation to bone and to extend at least I cmn distal to tip of the femoral ing has status beginning on the. first postoperative day . teric wires hadmost beencommon placedcomplications and the femoral prostional hips with fair clinical scores in patients be oneFig. of 2from the following THA be reported The of this with study acrylic crometer, anteroposterior radiographs of time the RSA technique, however, requires . JtoBone Joint Surg 53A purpose :9o3, 1971 stern . yet . Cortical widths measured atsignificant six sites, thesis inserted, the remaining five spheres were imrheumatoid Clinical and arthritis plain radiographic and severe functional evaluations impairwere oba total hip (THA) .toWhereas the is5 .to(,alante report.1, theRostoker incidence and severity of HO in W, Lucck R et al : Sintered fiber pelvis andarthroplasty proximal femur extending distal toincidence the tip and extremely close attention detail, from imaging ment 1 .2 . The 45 unit offset stem was associated with metal composites as a basis fur attachment of implants HO has varied from 5 to 90%, the presence of consecutive series of primary uncemented THA and of of prosthesis and fromeach frog-leg lateral radiothethe patient to digitizing stereoradiograph arid significantly loosening than:101, the approach 40 turn stem to bonethe . greater J effect Bone Joint Surgoperative 53A 1971 determine of the (anaprocessing functionally significant amount of ectopic has theproximal data . graphs of the femur extending distalbone to the Results neck, and I high neck prostheses used . There were (P < .02) . Jarcho . 6 M vs : Calcium phosphate ceramics as hardHOtissue terolateral posterior) on postoperative in a been found to range from I to 27% . 3 The etiology tip of the prosthesis . hydroxvapatite-augiiietited Anatomic offset was considered arid 13 This 13 .0evaluation mm, 22 14of .5 mm, 38 16 .0 mm, and 43 17 .5 Significant prosthetics calcar . Chinundergoing Orthop resorption 157 :259 was . 1981 seen in only 17 group of patients uncemented THA using of this reproduced HO remains but predisto have ifunknown, theTHA offsetoffers of reported theseveral operated side nonaugmented porous suggesTechnical mm stems used- The incidence of heterotopic ossifihips 7 . (14 DcGroot K,range, DcPutter C10 . Silvans-Smut PAP .6% ; 3mm) . Serial measurement : Transmuan anatomic stem with circumfe_rential porous posing factors include with osteoarthrosis, 4 7 (the .horizontal distancethose from the center of rotation tions Charnley and radiography cosal implants dense hydroxyapatite J Prosthet cation was none inevaluation 66`Z,, grade Iplain in 15%, grade II inat of cortical andofevaluation of cortical. hypertrocoating . width femoral hematoma formation," operative approach of thefollow-up femoral head to (lie center line of significant the used,` femoral Ninety-eight components were placed in early not show Dent 49 :87, 1983 7%, grade It in intervals 1]%, and do grade IV inany 1% . Sevcntyphy showed no trend toward distal cortical hypertroand those with diagnoses of ankylosing sponstem) was within 5 mm of thefemoral anatomic side .types Stern neutral alignment, 3 in vans, and 15 in valgus-The differences withthe the various implant 8 . Galante The need a standardized evalfive percent of the hips had equal leg lengths 10 phy, with theJ :medial andfor lateral corticessystem at thefurprosdylitis alignment and(neutral, diffuse idiopathic varus, valgus) skeletal was hyperostocollar wasresults placedofinside thesurgeryneck in(editorial) 16 hips and on or postoperative weight-bearing protocols .recorded This may. uating total hip J Bone within I cin . thesis tip remaining stable after surgery . Only one Materials and Methods sis Heterotopic .' ossification It hydroxyapatite appears that was agraded mutifactorial using theetiology classifiis the Joint proximomedial neck in 100 hips . Only suggest that augmentation and 12 Surg 67A :51femoral I, 1985 hip9 .showed significant calcar resorption (6 turn) and Fig . .4. Greater trochanter Im VC, Aglictti P elmore al : Radiology of total likely cation of postoperative Brooker et at .' Calcarweight resorption wasdo mea12% Salvati of the EA, stems filled 80% or of the femoral weeks of partial bearing not Clinical Ratings distal cortical hypertrophy, thus behaving more like technique . spheres were imhip replacements . Clio the Orthop 121 :74, 1976 or latsured and the date of its appearance was recorded medullary canal in either anteroposterior provide any discernable advantages . More It has been recently suggested that the probably, incidence. Ninety-five patients planted through the cut sura10.high modulus implantsrereophotogrammeriv . who underwent 112: aprimary Selvik G : Roentgen method though, Using it the indicates Hospital that for clinical Special Surgery evaluation hip and score, plain Three and millimeters of HO or is greater higher following considered uncemented signifieral planes .THAs Femoral cement technique was study satisfacface severity after the stem and the tro- was uncemented were included inttte this and tot' the study of the kinematics of skeletal system 69 hips were rated as excellent, 38 were rated as cant .."Subsidence was measured andoperative the date of its tory in 77% of the hips . In 87% of the hips deemed. radiography lack the the precision required to reliably THA However, approach chanteric wires hadeffect been of an Survivorship reviewed in aAnalysis retrospective fashion . The patients Acta Orthop Scand Suppl 60 :1 . 1989 good, were was rated as fair, 5 were as than poor 3. appearance recorded . and Subsidence greater unsatisfactory, the reason was the presence of less assess prosthetic fixation . Therated stereoradioplaced4. early were dividedB,into two groups based the operative 11 . Mjoberg trancson LL Selvik G : on instability, nugraThe hip scores improved from a preoperative mean ofas mm was considered significant andprosthetic interpreted than 3 mm of the mantle lateral lengths to the distal graphic data most precisely reveal migraBecause oflaxity the cement variable follow-up retion, and of total hip prostheses : apatients roentgen sterapproach used . Group I consisted of 52 from 17 tion .8 in points all groups, (range, but 10-29 it points) should he to noted a postoperative that migraported, survivorship analysis was performed (Fig . 4) . gross loosening . Femoral component radiolucent stem . Eighty-nine of the hips were 40 mm offset and study hiam the Deparbrrervs of''Orlhopaedic .Surgery and tRadiclogv, Tu. Acta Orhop 55 : t41 . the eophotogrammeiric US Naval Hospital (Oakland, CA)Scand who undermean of 32 .7SdroeI points or and an excellent result . were Pain. relief Failures weremmdefined radiographic lane lines University (stem-cement of Medicine, hone-cement) New Orleans. Louisiana mea27 were 45 offset .asAnatomic offsetevidence within 5ofmm tion rates are unaltered by the presence of 1984 went 63 noncemented THAs from 1987 to 1989 Reprint requests Dr . Robert Department of Orthopacsured using the:augmentation method Gruen et al .,' and was hydroxyapatite also excellent, withofaBarrack, mean or earlier follow-up unprotected score of definite femoral loosening . Survivorship this cethe date was reproduced in 57 C,ofHansson 81 hipsLI(70%) in which it 12 . Mjoberg B, Selvik et al for : Mechanical 1430 Tulane Avenue, New Orleans . LA 70112 . using the LSF hipfemoral system (Implant See9dics-SL32, .2 their compared toweight a preoperative . This mean suggests ofpresence 3 .5 that . Funcenmented titanium component was of appearance was recorded . The and could be assessed, and within 10Technology, in89 70-of 77 postoperative hearing 3% loosening of total hip prostheses. Jmm Bone Joint Surg tion improved thedoleast, fromwere a preoperative mean at 4 68B_770, years (95(% confidence interval) location of cement fractures recorded . Possible, hips (91"/o) .1986 There were 92 low neck, 23 medium hanced surfaces not alter femoral component mi. cording to the initial studies of Selvik, 10 the limits of

641

The Journal of Arthroplasty Vol . 9 No . 6 1994 Titanium Titanium Femoral Components Components Tompkins et et al 625 626 638 The The Journal Journal of of Arthroplasty Arthroplasty Vol Vol Hydroxyapatite-augmented .. 99 NoNo.. 66 December December 1994 1994 Femoral and Nonaugmented THA ••e Tompkins Ciccotti et al al. . . 627 6 33

Table fem1 . Variables ofgration 4Studied unprotected weight-bearing does not jeopardize .0 points in human to a postoperative THA and that 6 .6earlier points .unprotected Moderate oral fixation . Patient Data improvement weight bearing in does mean not ambulation jeopardize and femoral hip motion implant Radiographic Data The parameters traditionally used to assess prosscores was seen, increasing from 4 fixation, regardless of coating design .8 to 8..1The points initially and

Heterotopic Ossification Alignment : neutral, yams, valgus Following Uncemented Total Hip Arthroplasty Heterotopic weight that has heretofore been lacking of precision . Ac- ossification more of a reflection of bony ingrowth than true miAg

5 .5 to 8incidence thetic implant fixation have remained, in large part, .7 points,ofrespectively visual analog . Overall, thigh pain the patients with the Stem-canal fill ((%)lower : anteroposterior and lateral Sex rudimentary degreereconstruction seemed quite satisfied with their results hydroxyapatite-augmented stems, however, . may be Height . The RSA, however, provides aAnatomic

Diagnosis Calcar resorption Radiographic (significant if - 3 Results mm) gration and as such, adds some validity to the theoHospital for Special surgery hip score Subsidence (date seen) Effect thelin-Operative Approach RSA Stein havesize been determined as 0 .05-0 .1of mm Radiolucencies for retic advantages of .enhanced-surface prostheses . (stern-cement, bone-cement date recognized'widthtzone) There were no obvious cement fractures seen on Offset size and 0 .2° for rotation . In 1980, Cement fractures (location, date recognized) ear translation BaldWhile a plethora of literature exists attesting to the any radiograph . Two hips one patient with chronic Neck length Femoral cortical nidlh Iproximal, rnidstern, distalinstein) ursson et al ."' evaluated acetabular prosthetic migraadvantages of hydroxyapatite in the animal hip CmnpricaIion' Cement technique renal (I)orr criteria) failure and severe metabolic bone disease had tion in four patients with rheumatoid arthritis using difference model, few reports describe the effects of such surLeg-length Robert Bischoff, MD,* James Dunlap,complete MD,* Lawrence Carpenter, BS,* bone-cement radiolucent lines around the RSA technique over a 24-month period . Revision No clini-(date performed) faces on human hip implants . This study utilizes the both components and bilateral femoral subsidence at Edward DeMouy, MD,t and Robert Barrack, MD* cal or plain radiographic signs of loosening were RSA technique to better define the role of enhanced 3 years, which progressed at 5 years . The patient's noted, while all patients demonstrated gradual acesurfaces in human THA . The long-tern implications overall medical condition precluded revision . Five tabular migration up to 1 .8 mm and rotation up to of these initial findings, however, await further clinihips showed a femoral stem-cement radiolucenl line 5 .5° with Translation and rotation greatcal, plain and radiographic, and RSA follow-up evalupoints or aRSA pain. rating of 3 points or less were was considprobable, definite loosening (dehonding) in Gruen zone component 1 that progressed to were cysest inpoor the. initial months after THA. M,joberg et al .,` ation . ered determined using the criteria of Harris and McGann tic cortical erosion at the bone-cetnent interface in. 4 inPatient 1986, and Snorrason and Karrholin," in of 1990, charts Abstract: and radiographs A consecutive were series reviewed 112 by primary Theuncemented corticaltotal width hipofarthroplasties the femur was measured in the midfcmoral zones (Fig . 3) . Six femoral compousing the same type of prosthesis was reviewed for the incidence and of (Fig . 2) on each usedauthor the RSA technique to evaluate cemented and one (G . S T . . .) Variables studied are shown three medial lateral severity locations Fig . 2 . Tantalum spheres measuring 0 .8 mm in diameter . nents showedand isolated stem-cement radiolucenl References heterotopic ossification (HO) . Sixty-three of these patients underwent a posterior apuncentented THA . Their studies detected component in Table 1 . All data were entered and stored on an postoperative radiograph . technique The ratios.inof the final Fig . 3less . Lesser trochanteric Spheres werefolimlines than or equal to I runt Gruen zone 1proach (group 1) and 49 underwent an anterolateral approach 2) .femoral The twocanal through migration in 35-50% of implants within 4-12 IBM PS2 computer (International Business Malow-up widths to (group the initial postoperative widths planted from the broached the Thus, such a total of sex, 13 femoral components (11%) were groups were virtually identical risk factors, as age, estimated blood months after THA . These investigators identified RSA calcar 1 . Charnley . J : .Anchorage of thefill femoral head prosthesis chines, Armonk, NY) using the Data Ease (Datawhen Ease were calculated Stern canal was determined on judged to be definitely loose the criteria of Harris loss, lengthforof detection surgery, and diagnosis were compared . Patients in group 1 had by as the most precise methodCO) of prosthetic to the shaft of the femur .aradiographs JsignifiBone JointasSurg 428 :28, International, Trumble, database. The data were anteroposterior and lateral described All procedures were carried using and theseverity same surgiMcGann .'2 No femoral cantly lower out incidence of HO thanand those in group . The overall component incidence showed prob1960 migration and, indirectly, fixation .Analysis Their findings then transferred the Statistical System by Robinson et uncemented al .' Leg-length discrepancies were cal technique byofto orclass under the direct supervision or possible loosening III or IV 110 was very lowof(8%), able indicating that total hip . 2 . Amstutz HC, Markolf Kl ., McNeice (,M et al : lesser Loosensuggest that this technique allowspackage more significant (SAS Institute Cary, NC) software forstatiscalculated by measuring the distances front the in itself is not predisposed to moderate orof severe degrees of trochanteric HO . Patients the investigators arthroplasty . planted Theing six into hips the with greater isolated Gruen Zone bed I through stem-cethe total hip components : cause and prevention interpretation of early follow-up data was for THA . Our analysis Irochanters to pelvic bony landmarks . Cement tech- . tical analysis undergoing total hip2)arthroplasty through an anterolateral approach had tantalum uncemented spheres (Fig .performed were Eight 0 .8 .mmSurvivorship cut surface (Fig . 4) . ment radiolucent lines were rated as good or excelp . 102 . In the Flip : proceedings of the Fourth Open stereoradiographic data corroborate these results as using methoda of Armitage with failure defined considered if the criteria dehigher incidence of 110 than those undergoing anique posterior approach in satisfactory this series . Society, Key placed the periprosthetically at the time of THA using a After surgery, all patients were treated intralent Scientific atwas the mostMeeting recent offollow-up the Flip evaluation CVwith Mosby (range, . St . some degree of linear migration was detected in all as radiographic evidence : of hip, definite arthroplasty, loosening uncemented, of the heterotopic scribed ossification, by Dorr et operative al .' were approach met . This . requires that words hand-held implanter as described by Aronson et al ." Louis, 1976 . The 60-72 venous months) antibiotics for 48 seven hourships and received with femoral warfarin groups within 1 year of THA . These findings were component . of there be(Coumadin, a complete, intact mantle adjacent 3 . Beckenbaugh RD .DuPont, [[sit up cement DM : Total hip arthropiasly On completion the femoral broaching, but before sodium Wilmington, DE) as a: bone-cement erosions or radiolucent lines and/or not reflected in our Charnley or plain radiographic to each femoral component. There must he a minia review of three hundred and thirty-three eases with insertion of the actual stem, three of the spheres were femoral routinecomponent thromboembolic subsidenceprophylaxis had fair or. poor All patients cliniresults, thereby implying that RSA may provide the mum of 3 mm of cement in the proximomedial third lung hullow-up . J Bone Joint Surg 6UA :306, 1978 Radiographic Review implanted via the canal through the calcar into the cal were hipenrolled scores at in their a standardized most recentrehabilitation follow-up evaluapromost precise assessment of early implant migration . and mm accordance in the distal lateral third, andweight-bearcement had: 4 . 3Pilliar RM, Welsh RI), MacNab I : Surgical implants lesser trochanteric region (Fig . 3) . After the trochantion gram (range, in 24-60 with months) their specific . There were two addiHeterotopic (HO) haspossible reported to on the of HO porosity following strictly uncemented Measurements were made, using abeen hand-held Obtaining the ossification theoretic precision with mithe the incidence role of surface inthe fixation to bone and to extend at least I cmn distal to tip of the femoral ing has status beginning on the. first postoperative day . teric wires hadmost beencommon placedcomplications and the femoral prostional hips with fair clinical scores in patients be oneFig. of 2from the following THA be reported The of this with study acrylic crometer, anteroposterior radiographs of time the RSA technique, however, requires . JtoBone Joint Surg 53A purpose :9o3, 1971 stern . yet . Cortical widths measured atsignificant six sites, thesis inserted, the remaining five spheres were imrheumatoid Clinical and arthritis plain radiographic and severe functional evaluations impairwere oba total hip (THA) .toWhereas the is5 .to(,alante report.1, theRostoker incidence and severity of HO in W, Lucck R et al : Sintered fiber pelvis andarthroplasty proximal femur extending distal toincidence the tip and extremely close attention detail, from imaging ment 1 .2 . The 45 unit offset stem was associated with metal composites as a basis fur attachment of implants HO has varied from 5 to 90%, the presence of consecutive series of primary uncemented THA and of of prosthesis and fromeach frog-leg lateral radiothethe patient to digitizing stereoradiograph arid significantly loosening than:101, the approach 40 turn stem to bonethe . greater J effect Bone Joint Surgoperative 53A 1971 determine of the (anaprocessing functionally significant amount of ectopic has theproximal data . graphs of the femur extending distalbone to the Results neck, and I high neck prostheses used . There were (P < .02) . Jarcho . 6 M vs : Calcium phosphate ceramics as hardHOtissue terolateral posterior) on postoperative in a been found to range from I to 27% . 3 The etiology tip of the prosthesis . hydroxvapatite-augiiietited Anatomic offset was considered arid 13 This 13 .0evaluation mm, 22 14of .5 mm, 38 16 .0 mm, and 43 17 .5 Significant prosthetics calcar . Chinundergoing Orthop resorption 157 :259 was . 1981 seen in only 17 group of patients uncemented THA using of this reproduced HO remains but predisto have ifunknown, theTHA offsetoffers of reported theseveral operated side nonaugmented porous suggesTechnical mm stems used- The incidence of heterotopic ossifihips 7 . (14 DcGroot K,range, DcPutter C10 . Silvans-Smut PAP .6% ; 3mm) . Serial measurement : Transmuan anatomic stem with circumfe_rential porous posing factors include with osteoarthrosis, 4 7 (the .horizontal distancethose from the center of rotation tions Charnley and radiography cosal implants dense hydroxyapatite J Prosthet cation was none inevaluation 66`Z,, grade Iplain in 15%, grade II inat of cortical andofevaluation of cortical. hypertrocoating . width femoral hematoma formation," operative approach of thefollow-up femoral head to (lie center line of significant the used,` femoral Ninety-eight components were placed in early not show Dent 49 :87, 1983 7%, grade It in intervals 1]%, and do grade IV inany 1% . Sevcntyphy showed no trend toward distal cortical hypertroand those with diagnoses of ankylosing sponstem) was within 5 mm of thefemoral anatomic side .types Stern neutral alignment, 3 in vans, and 15 in valgus-The differences withthe the various implant 8 . Galante The need a standardized evalfive percent of the hips had equal leg lengths 10 phy, with theJ :medial andfor lateral corticessystem at thefurprosdylitis alignment and(neutral, diffuse idiopathic varus, valgus) skeletal was hyperostocollar wasresults placedofinside thesurgeryneck in(editorial) 16 hips and on or postoperative weight-bearing protocols .recorded This may. uating total hip J Bone within I cin . thesis tip remaining stable after surgery . Only one Materials and Methods sis Heterotopic .' ossification It hydroxyapatite appears that was agraded mutifactorial using theetiology classifiis the Joint proximomedial neck in 100 hips . Only suggest that augmentation and 12 Surg 67A :51femoral I, 1985 hip9 .showed significant calcar resorption (6 turn) and Fig . .4. Greater trochanter Im VC, Aglictti P elmore al : Radiology of total likely cation of postoperative Brooker et at .' Calcarweight resorption wasdo mea12% Salvati of the EA, stems filled 80% or of the femoral weeks of partial bearing not Clinical Ratings distal cortical hypertrophy, thus behaving more like technique . spheres were imhip replacements . Clio the Orthop 121 :74, 1976 or latsured and the date of its appearance was recorded medullary canal in either anteroposterior provide any discernable advantages . More It has been recently suggested that the probably, incidence. Ninety-five patients planted through the cut sura10.high modulus implantsrereophotogrammeriv . who underwent 112: aprimary Selvik G : Roentgen method though, Using it the indicates Hospital that for clinical Special Surgery evaluation hip and score, plain Three and millimeters of HO or is greater higher following considered uncemented signifieral planes .THAs Femoral cement technique was study satisfacface severity after the stem and the tro- was uncemented were included inttte this and tot' the study of the kinematics of skeletal system 69 hips were rated as excellent, 38 were rated as cant .."Subsidence was measured andoperative the date of its tory in 77% of the hips . In 87% of the hips deemed. radiography lack the the precision required to reliably THA However, approach chanteric wires hadeffect been of an Survivorship reviewed in aAnalysis retrospective fashion . The patients Acta Orthop Scand Suppl 60 :1 . 1989 good, were was rated as fair, 5 were as than poor 3. appearance recorded . and Subsidence greater unsatisfactory, the reason was the presence of less assess prosthetic fixation . Therated stereoradioplaced4. early were dividedB,into two groups based the operative 11 . Mjoberg trancson LL Selvik G : on instability, nugraThe hip scores improved from a preoperative mean mm was considered significant andradiograph interpreted as than 3stern mm of the cement mantle lateral tostem-cement the distal graphic data most precisely reveal prosthetic migraBecause ofin the variable follow-up reFig. 3 . (A) Two-month anieroposterior of aof titanium-alloy a 67-year-old woman . (B?: lengths tion, and laxity of total hip prostheses roentgen sterapproach used . Group I consisted of 52 Aapatients from 17 tion .8 in points all line groups, (range, but 10-29 it points) should he to noted a postoperative that migraported, survivorship analysis was performed (Fig . 4)At. radiolucent gross loosening (dehonding) . Femoral has component developed radiolucent in zone I at 44 months stem after . Eighty-nine surgery . The of patient the hips was were asymptomatic 40 mm offset . (C) and eophotogrammeiric study hiam the Deparbrrervs of''Orlhopaedic .Surgery and tRadiclogv, Tu. Acta Orhop Scand 55 : t41 . the US Naval Hospital (Oakland, CA) who under60 months alter surgery, The stem-cement radiolucent line increased iu width.asand cystic offset cortical erosion 5is mean of 32 .7SdroeI points or and an excellent result . were Pain. relief Failures weremmdefined radiographic evidence ofmm lane lines University (stem-cement of Medicine, hone-cement) New Orleans. Louisiana mea27I has were 45 offset Anatomic within tion rates are unaltered by the presence ofin zone 1984 went 63 noncemented THAs fromrevised 1987 atto7 years 1989. noted Reprint . using Therequests patient Dr has . Robert moderate thigh Department pain of Orthopacnonsteroidal antiinflammatory medication and sured the:augmentation method ofaBarrack, Gruen et al .,'requiring was hydroxyapatite also excellent, with mean or earlier follow-up unprotected score of definite femoral loosening . Survivorship this ceand the date was reproduced in 57 C,ofHansson 81 hipswas in which it 12 . Mjoberg B, Selvik LI(70%) et al for : Mechanical 1430 Tulane Avenue, New Orleans . LA 70112 . using the LSF hipfemoral system within (Implant See9dics-SL32, .2 their compared toweight a preoperative . This mean suggests ofpresence 3 .5 that . Funcenmented titanium component was of appearance was recorded . The and could be assessed, 10Technology, in89 70-of 77 postoperative hearing 3% loosening of total and hip prostheses. Jmm Bone Joint Surg tion improved thedoleast, fromwere a preoperative mean at 4 68B_770, years (95(% confidence interval) location of cement fractures recorded . Possible, hips (91"/o) .1986 There were 92 low neck, 23 medium hanced surfaces not alter femoral component mi. cording to the initial studies of Selvik, 10 the limits of

641



628

The Journal of Arthroplasty Vol . 9 No . 6 December 1994 1 0.95 0.9 0.85

P R 0 B A 8

0.8 0.75 0.7

L T Y

0 .65 0 .6 0

12

24

36

48

60

72

54

99

MONTHS OF FOLLOW UP

Fig . 4 . Survivorship curve to 4 years showing 95% confidence intervals .

Revisions Three revisions were performed for aseptic femoral loosening with cystic conical resorption at 3 .5, 7, and 7 .5 years, respectively . ht addition, revision is pending in two patients with component loosening and cystic cortical erosion . In the patient with chronic renal failure and metabolic bone disease who had bilateral extensive bone-cement radiolucent lines and component migration, severe medical problems precluded revision. Overall, revision was performed or is pending in 4 .3% of the hips studied .

Complications Postoperative complications occurred in 18 patients . A postoperative myocardial infarction developed in three patients, but they recovered without further sequela . Deep venous thrombosis occurred in three patients and asymptomatic and symptomatic pulmonary embolism occurred in five patients . One patient developed a metastatic deep infection at 12 months after surgery and the implants were removed . In two hips, there were wound hematomas that required evacuation . A nerve palsy occurred in two hips (1 ipsilateral saphenous, I contralateral peroneal) . The peroneal nerve palsy partially recovered ; the saphenous nerve injury completely recovered . Prosthesis dislocation occurred in two hips, which were treated with closed reduction and immobilization .

Discussion Modern femoral components are fabricated of either cobalt-chrome or titanium (Ti6A14V) alloys . Of these two super alloys, cobalt-chrome has a higher clastic modulus . With a cobalt-chronic-alloy

femoral component, the greatest proportion of load is transferred from the prosthesis to bone at the distal end of the prosthesis .' 3 Thus, distal cement stresses are greatest . Proponents of high-modulus femoral components believe that distal stress transfer is tinponant because proximal cement overload represents the greatest threat to prosthesis fixation. Distal stress transfer with high-modulus prostheses has been demonstrated both in laboratory and clinical studies .' .1° A result of distal stress transfer is proximal stress shielding of the femur, which may be the cause of progressive calcar resorption . Some investigators report that calcar resorption is the result of vascular disruption or thermal necrosis of bone at the time of surgery, or a foreign body response to polyethylene debris ." '','2 Many investigators report that significant (?3 mm) calcar resorption is the result of remodeling of stress-shielded bone . Thomas et a] 10 reported a 42% incidence of significant calcar resorption with the high-modulus CAD femoral component (Howmedica, Rutherford, NJ) . Lower modulus titanium-alloy femoral components have been shown to increase stress transfer to both the proximal femur and bone-cement . The addition of a collar, which contacts the calcar, results in proximal bone stresses measuring 80% of normal .v " Proximal load transfer is anticipated to load the calcar and prevent stress shielding, thus minimizing calcar resorption . With retention of the calcar, it is hoped that better support for the proximal cement is provided . Distal cement stresses, which are the greatest stresses encountered,',' .14 should be lessened with titanium-alloy sterns . The clinical results of a cemented titanium-alloy femoral component were first reported by Sarmiento and Gruen .'s With the STH prosthesis (Zimmer, Warsaw, IN), significant calcar resorption was seen in only 4.3% and distal cortical hypertrophy in only 2 .2% of the hips studied . Radiolucent lines were seen in 17 .3% of the hips, primarily in the proximal third of the stem ." Recently, Robinson et al .' reported a 48 .9% incidence of radio] ucent lines and a 2 3 .4% incidence of femoral subsidence at an average of 8 .8 months after implantation of the DF-80 prosthesis, which is a titaniumalloy femoral component with a titanium-alloy femoral head . Radiolucent lines were primarily located in the proximal femoral zones and were correlated with male sex and larger (45 mm) offset stems . No discussion of calcar resorption or distal cortical hypertrophy was included in that study . The results of this cemented titanium femoral component are better than those reported for the similar DP-80 titanium-alloy prosthesis (Zimmerl . However, the results are inferior to those reported for cemented cobalt-chrome-alloy stems . 4 . ' 6 . "The DF-80 demon-

Titanium Femoral Components • Tompkins et al . strafed early and progressive bone-cement radiolucent lines and subsidence . Robinson ct al .' postulated that the use of conical reamers, not used by the senior author in this series, resulted in a large proximal medullary opening with loss of bone support for the prosthesis . This is suboptimal in a lowmodulus prosthesis designed for proximal stress transfer . In addition, titanium wear products from the articulating surface of the DF-80 may have infiltrated into the bone-cement interface and adversely affected fixation . The usual mechanism of failure for the Triad femoral component was different than that described for the DF-80 femoral component. With the exception of two hips, which developed extensive bone-cement radiolucent lines in a patient with renal failure and severe metabolic bone disease, all loose femoral components in this study initially failed by debonding (separation of the prosthesis from the cement) with development of a stem-cement radiolucent line in Gruen zone 1 . Five of the 11 components that debonded eventually developed cystic cortical erosion of the femur. Recent studies have suggested that debonding is the initial step in loosening of cemented femoral components .'"'" Cystic conical erosion of the femur may be the result of stem motion, wear debris, or both . It was not possible to predict which loosened stems would ultimately develop cortical erosion . The results of the Triad femoral component (loosening rate of 11% with a mean follow-up period of 4 .8 years) are inferior to the results published by others using a cobalt-chrome-alloy prosthesis (1 .3-1 .7% loosening rate with a mean follow-up period of 5-6 years) .' . "There are several possible reasons for the higher rate of failure of this cemented titanium-alloy femoral component . One may be a problem with the design and insertion of the Triad femoral component . Although this prosthesis is intended to provide greater than 80% canal fill in the anleroposterior and lateral planes, this was achieved in less than 13% ofthe cases, despite careful tcrnplating and reaming . Robinson et al .' reported satisfactory canal fill in less than 50% of their hips studied using the DF-80 prosthesis . The inability to achieve a satisfactory fill of the medullary canal could cause an irregular cement till and a greater incidence of femoral component loosening . A more likely explanation may he fatigue fracture of the proximomedial cement mantle that is loaded more with the lower modulus titanium-alloy stem . The appearance of a radiolucent line at the stem-cement interlace in Gruen zone I of the femur indicates debonding of the cement from the implant arid implies fracture of the medial cement ." A femoral stern that is rough-

629

surfaced or precoated at the proximolateral aspect may have prevented this occurrence 2" The observation of greater loosening with the 45 mm offset stem also suggests overload of the proximal cement mantle . The greater bending moment of the larger offset stem would be expected to generate higher proximal cement stresses than the 40 mm component . Robinson et al .' also found an association of the 45 mm offset stem with early loosening of the DF-80 femoral component . Finally, the polymethyl methacrylate cement used in this series was not centrifuged or vacuum-mixed as is currently recommended-" It is possible that this improvement could have strengthened the proximomedial cement arid stem-cement interface arid decreased the overall rate of failure . The desired tight stem-canal fit conflicts with the thick distal-lateral cement mantle suggested by Dorr et al .' as a criterion of satisfactory cement technique . Thus, the stems likely to fill 80% or more of the femoral canal are not likely to have the minimum 3 mm distal-lateral cement mantle and vice versa . This was our experience, in which 23% of the hips were considered to have unsatisfactory cement technique ; but of these hips, the distal-lateral cement mantle was less than 3 mm in 87% . One of the advantages of the Triad femoral component is its versatility with multiple offsets, neck lengths, and stem sizes . With this wide inventory of prostheses, the goal of anatomic restoration within 5 and 10 tom was achieved in 70 and 91%, respectively, of the hips that could be measured . Proximal load transfer appeared to have been ohtained with the titaniuin-alloy femoral component Significant calcar resorption was seen in only 19% of the hips . This is much lower than the 42% incidence seen with the CAD prosthesis .'" Despite the relatively low incidence of significant calcar resorption, it is clear that the proximal sites ; transfer is not normal . Lewis el al ." have reported that even under optimal conditions (collared titanium-alloy prosthesis with perfect collar-calcar contact), a low-niodtilus prosthesis will restore only 80% of normal calcar Stress . The results of this study show an I I'„ incidence of loosening at a mean follow-up period of 4 .8 years with the cemented titanium-alloy stem and cobaltchrome-alloy head femoral components . Radiographic analysis demonstrated that the lower modules femoral stem behaved in viva similar to what was predicted in finite element analysis and experimental laboratory studies . The proximal boric is loaded more normally than with a cobalt-chrome stem, and calcar resorption and distal cortical hypertrophy are unusual . The disadvantage is that proximal cement stress is greater . The result of excessive proximal cement

The Journal of Arthroplasty Vol . 9 No . 6 1994 630 ..999No Titanium Titanium 1994 Femoral Components Components Tompkins et et al 625 626 638 The The The Journal Journal Journal of of of Arthroplasty Arthroplasty Arthroplasty Vol Vol Vol Hydroxyapatite-augmented NoNo.. 66 December December December 1994 1994 Femoral and Nonaugmented THA ••e Tompkins Ciccotti et al al. . . 627 6 33 Table ce1 . Variables mum inin femoral prostheses . 6Clin Orthop 158 :270, stress is proximolateral medial ofgration 4Studied unprotected weight-bearingdebonding does not and jeopardize fem.0 points human to a postoperative THA and that .6earlier points .unprotected Moderate 1981 bearing ; in some cases, cystic erosion of ment oral fragmentation fixation . Patient improvement weight in does mean not ambulation jeopardize and femoral hip motion implant Data Radiographic Data 9fixation, . Lewis ., Askew MJ,ofWixson RL et al : The influence theThe femur may develop, probably used due to parameters traditionally to particulate assess prosscores wasJ1 regardless seen, increasing from 4 coating design .8 to 8..1The points initially and Ag Alignment : neutral, of yams, prosthetic valgus stiffness and of a .calcar collarthe on patients stresses 5lower cement thetic debris implant. fixation have remained, in large part, .5 to 8 incidence .7 points, ofrespectively visual analog Overall, thigh pain with the Stem-canal fill ((%) : anteroposterior and lateral Sex in the proximal end of the femur with a [emented We have the use of titaniurn-alloy fem- reconstruction rudimentary . The RSA, however, provides a degree seemed quite satisfied with their results hydroxyapatite-augmented however, . :280,may Heightabandoned Anatomic femoral component J Bone stems, Joint Surg66A 1984be Heterotopic oral components weight that forhascemented THA been . If titanium-alloy of precision heretofore lacking . Ac- ossification more of a reflection of bony ingrowth than true mi10 . ThomasifBJ, Salvati EA, Small RD : The CAD hip Diagnosis Calcarthe resorption (significant - 3 Results mm) stems areto to used for cemented arthroplasty, cording thebeinitial studies of Selvik, 10 the limits of Radiographic gration and as such, adds some validity to the theoHospital for Special surgery hip score Subsidence (date seen)arthroplasty . .) Bone Joint Surg 68A :640, 1986 stern-cement interface strength must .1 be mm improved . RSA Stein havesize been determined as 0 .05-0 for linadvantages of .enhanced-surface prostheses . Radiolucencies (stern-cement, bone-cement 11retic .There Blacker G .1, Charnley Jdate recognized'widthtzone) :cement Changes in the upper lemur were no obvious fractures seen on The Offset size andstem have a. rough Cement surface fractures (location, date recognized) ear proximolateral translation 0 .2°should for rotation In 1980, BaldWhile a plethora of literature exists attesting to the low friction Chn Orlhop :15, any after radiograph . Two ardrroplasty hips one. patient with 137 chronic length with polymethyl Femoraltocortical nidlh Iproximal, rnidstern, distalinstein) or be Neck precoated ursson et al ."' evaluated acetabular methacrylate prosthetic migra1978 advantages of hydroxyapatite in the animal hip CmnpricaIion' Cement technique renal (I)orr criteria) failure andAmstutz severeHC, metabolic bone DL disease had prevent cement should probably be cen12model, . Markolf ., Flied surof tion in debonding, four patients with rheumatoid arthritis using difference few ICI reports describe Hirscliowitz the effects of: such Leg-length Robert Bischoff, MD,* James Dunlap, MD,* Lawrence Carpenter, BS,* complete bone-cement radiolucent lines around trifuged or vacuum-mixed, and theperiod 45 mm. Revision offset cafcar contact onimplants femoral .component mieromovethe RSA technique over a 24-month No clini-(date performed) faces on human hip This study utilizes the components and bilateral subsidence at DeMouy, MD,t and both Robert MD* wenl . JBarrack, Boneto Joint Surg 62A femoral :131 1980 stern should avoided .Edward Unless modifications cal or plainberadiographic signsthese of loosening were RSA technique better define the5,role of enhanced 3 years, which progressed at 5 years . I3surfaces . Tarr RR,inClarke Gruen TA .long-tern SarmientoThe A : patient's Comparican be met, of cobalt-chrome-alloy femoral noted, whilethe alluse patients demonstrated gradual acehumanIf, . The THA implications overall medical condition precluded revision . Five son of loading behavior of femoral stems of Ti-6A Icomponents for cemented THA tabular migration up to 1 .8 mmis andrecommended rotation up. to of these initial findings, however, await further clinihips a femoral stem-cement line 4Vshowed and cobalt-chromium alloys : aradiolucenl three-din tensional 5 .5° with Translation and rotation greatcal, plain and radiographic, and RSA follow-up evalupoints or aRSA pain. rating of 3 points or less were was considprobable, definite loosening were finite element analysis . pcomponent .1 88 . Illprogressed Luckey HA .to Kubli (dehonding) in Gruen zone that cys-F est inpoor the. initial months after THA. M,joberg et al .,` ation . ered determined using the criteria of Harris and McGann Jr (eds) : Titanium alloys its surgical implants tic cortical erosion at the bone-cetnent interface in.: 4 References inPatient 1986, and Snorrason and Karrholin," in of 1990, charts Abstract: and radiographs A consecutive were series reviewed 112 by primary Theuncemented cortical total width hip of arthroplasties the femur was measured in . American for femoral Testing and Mathe ASTMSTP796 midfcmoral zones (FigSociety . 3) . Six compousing the same type of prosthesis was reviewed for the incidence and severity of usedauthor the RSA technique to evaluate cemented and one (G . S T . . .) Variables shown . three terials, medial Philadelphia, and lateral 1983 locations (Fig . 2) on each spheres 0studied .8 mm al in:are diameter Fig 2 . TantalumAmstutz nents showed isolated stem-cement radiolucenl 1 . .Wilson BC,measuring A et Total References heterotopic ossification . component Sixty-three these patients underwent a posterior ap-distribution uncentented THAdata . Their studies in Table 1 PD, . All wereCzernescki entereddetected and(HO) stored on hip an of 14, postoperative Oh I, Harris radiograph WH : Proximal . The strain ratios of the in folthe Fig . 3 . Lesser trochanteric technique . Spheres were imlines lessapproach than or(group equal 2) to IThe runt in Gruenfinal zone 1replacement with fixation by acrylic cement . J Bone proach (group 1) and 49 underwent an anterolateral two loaded femur. Boneinitial loin[.femoral Surg 61)4 :75, through 1978widths migration in 35-50% of implants within 4-12 IBM PS2 computer (International Business Malow-up widths to Jbroached the postoperative planted from the canal the Thus, a total ofGruen 13 femoral components (11%) were Joint Sing 54Agroups :207, were 1972 virtually identical when risk factors, such as age, sex, estimated blood 15 .1 .Sarmiento TAcanal :ofRadiographic analysis of lowon months after THA . These investigators identified RSA calcar Charnley . JA, : .Anchorage thefill femoral head prosthesis chines, Armonk, NY) using the Data Ease (Data Ease were calculated Stern was determined 2 . Brooker AF, Bowerman JW,ofRobinson Riley LH were compared judged to be titanium definitely loose bysignifithe criteria of Harris. loss, length surgery, RA, and diagnosis . Patients inof group 1 had modulus alloy femoral total hipasSurg components as the most precise methodCO) fordatabase. detection The prosthetic to the shaft femur .aradiographs J Bone Joint 428 :28, International, Trumble, data were anteroposterior andthe lateral described : Ectopic ossification following total hip replaceAll Jrprocedures were carried out using theof same surgiMcGann .' No femoral component showed probcantly lower incidence and severity of HO thanand those in group 2 . The overall incidence J Bone Joint Surg 67A :48, 1985 1960 migration and, indirectly, fixation .Analysis Their findings then transferred the Statistical by Robinson et uncemented al .' Leg-length discrepancies were ment : incidence and a method classification . System J Bone cal technique byofto or under the direct supervision or possible loosening class III orofIV 110 was very lowof(8%), able indicating that total hip 16RD, WHKl:. ., TheMcNeice eflert of et improved ce2 . Mulroy Amstutz HC,Harris Markolf (,M al : lesser Loosensuggest that this technique allowspackage more significant (SAS Institute Cary, NC) software forstatiscalculated by measuring the distances front the Joint Surg 55A :1629, 1973 in itself is not predisposed to moderate orof severe degrees ofcomponent HO . Patients the investigators arthroplasty . planted The six into hips the with greater isolated trochanteric Gruen Zone bed I through stem-cethe mented techniques on loosening In total ing total hip components : cause and prevention interpretation of earlyGM, follow-up data for . Our Survivorship analysis performed Irochanters to pelvic bony landmarks . Cement tech- . tical 3 .Eight Green analysis McNicce Amstutz HC total :was Modes failundergoing uncemented hipof through an anterolateral approach had .8 .mm tantalum spheres (Fig .THA 2)arthroplasty were 0TA, cut surface (Fig . 4) . hip replacement. J Bone Joint Surg 7213 . 1990 ment radiolucent lines were rated as good or excelp . 102 . In the Flip : proceedings of the:757 Fourth Open stereoradiographic data corroborate these results tirethe of method cemented stein-type components : a undergoing ra-asa using Armitage with failure defined considered if the dea of higher incidence of 110 than those anique approach in satisfactory this series . Society, Key 17 .posterior Russottl GM,Meeting Coventry MB, Flip Slanffer RN criteria placed periprosthetically at femoral the time of THA using After surgery, all patients were treated intra:CVwith Cemented lent Scientific atwas the most recent offollow-up the evaluation Mosby (range, . St . diographic analysis of loosening . Clin Orihop 141 :17, some degree of linear migration was detected in all as radiographic evidence : of hip, definite arthroplasty, loosening uncemented, of the heterotopic scribed ossification, by Dorr et operative al .' were approach met . This . requires that words total hip1976 arthroplasty with conlemporay techniques : hand-held implanter as described by Aronson et al ." Louis, 60-72 venous months) antibiotics . The for 48 seven hours hips and received with femoral warfarin 1979within groups 1 year of THA . These findings were component . of there be(Coumadin, a complete, intact cement mantle adjacent a five-year mnnlmum IOIIOw-up study, Clin Orthop 3 . Beckenbaugh RD . [[sit up DM : Total hip arthropiasly On completion the femoral broaching, but before sodium DuPont, Wilmington, DE) as bone-cement erosions or radiolucent lines and/ora: 4 . Harris WH,inMcGann WA : Loosening of radiographic the femoral not reflected our Charnley or plain to 235 each :141, femoral 1988 component. heeases apatients minia review of three hundredprophylaxis and thirty-three with insertion of the actual stem, three of the spheres were femoral routine component thromboembolic subsidence hadThere fairmust or. poor All clinicomponent alterimplying use of the medullary plugprovide technique . results, thereby that RSA may the 18 . Jasty M, Maloney WT Bragdan CR et6UA al:306, : Histomormum of 3 mm of cement in the proximomedial third lung hullow-up . J Bone Joint Surg 1978 Radiographic Review implanted via the canal through the calcar into the cal were hipenrolled scores at in their a standardized most recentrehabilitation follow-up evaluaproJ Bone Joint Surg 64A : 1064, 1982 studies of RI), the long-term responses most precise assessment of early implant migration . and 3Pilliar mm accordance in the distal lateral third, andweight-bearcement had: 4 .phological RM, Welsh MacNab I :skeletal Surgical implants lesser trochanteric region . 3) . After the trochantion gram (range, in 24-60 with months) their specific . There were two addi5 .Heterotopic Robinson RR,ossification Level] PL,(Fig Green TM, Bailey GA : Early (HO) haspossible reported to on to the well incidence fixed cemented of HO porosity following femoral strictly components uncemented .bone J Bone Measurements were made, using abeen hand-held Obtaining the theoretic precision with mithe the role of surface inthe fixation to and to extend at least I cmn distal to tip of the femoral ingJoint status beginning on the. first postoperative day . component Loosening DF-80 total hip teric wires hadmost beencommon placedcomplications andinthe femoral prostional hipsSurg with fair clinical scores in patients :1220, be femoral oneFig. of 2from the following THA has be reported of this with study acrylic crometer, anteroposterior radiographs of time the RSA technique, however, requires significant . Jto72A Bone Joint 1990 Surg The 53A purpose :9o3, 1971 stern . yet . Cortical widths measured six sites, arthroplasty . J the Arthroplasty 4 :55 . at 1989 thesis inserted, remaining five spheres were imrheumatoid Clinical and arthritis plain radiographic and severe functional evaluations impairwere ob19 . Jasty M : Why cemented femoral components become a total hip arthroplasty (THA) . Whereas the is5 .to(,alante report.1, theRostoker incidence and severity of HO in W, Lucck R et al : Sintered fiber pelvis and extending distal toincidence the tip and extremely close detail, from imaging 6 . Don LD, proximal Takei GK attention .femur Conaty JPto : Total hip arthroplasties ment 1 .2 loose . American Academy of Orthopedic Surgeons In. The 45 unit offset stem was associated with metal composites as a basis fur attachment of implants HO has varied from 5 to 90%, the presence of consecutive series of primary uncemented THA and of of prosthesis andforty-five fromeach frog-leg thethe toless digitizing stereoradiograph arid inpatient patients than years oldlateral . 1 BoneradioJoint structional Course Lecture XL 53A :than 151, 1991approach significantly loosening the 40 turn stem to bonethe . greater J effect Bone Joint Surgoperative :101, 1971 determine of the (anaprocessing functionally significant amount of ectopic has the data . graphs of65A the proximal femur extending distalbone to the Results Surg :474, 1983 20 . Ahmed AM, Raab S, Millet JF : Metill/cenient interface neck, and I high neck prostheses used . There were (P < .02) . Jarcho . 6 M vs : Calcium phosphate ceramics as hard tissue terolateral posterior) on postoperative HO in a been found to range from I to 27% . 3 The etiology tip of the prosthesis Anatomic offset wasRC, considered of. hydroxvapatite-augiiietited arid 7 .This Crowninshield Milroy strength in calcar cemented stem 157 fixation J Orthop Res 217: 13 13 .0evaluation mm, 22 14RD, .5 Brand mm, 38RA,16Johnston .0 mm, and 43 17 .5 Significant prosthetics . Chinundergoing Orthop resorption :259 was ..1981 seen in only group of patients uncemented THA using of this HOanalysis remains but predisto have : An reproduced of ifunknown, femoral theTHA offset component of reported thestein operated design side in nonaugmented porous several suggesJC . .6% 1984;K,range, Technical mm stems used- The incidence ofoffers heterotopic ossifihips 7 .105 (14 DcGroot DcPutter Silvans-Smut 3- C10. circumfe_rential mm) . Serial PAP measurement : Transmuanatomic with porous posing factors include those with osteoarthrosis, 4at7 hip arthroplasty . .[ Hone Joint Smrgradiography 62Aof:68, 1980 21an . Wilson RI ., stem (thetotal distance from the center rotation I autenschlager ED . Novak MA.:J Vacuum tions .horizontal Charnley evaluation and plain cosal implants ofevaluation dense hydroxyapatite Prosthet cation was none in 66`Z,, grade I in 15%, grade II in of cortical width and of cortical hypertrocoating . 8 . the Crowninshield . Brand RAnot . Johnston mixing of acrylic bores eeurett hematoma formation," operative approach used,` . J Arthroplasty 2 :141in . of femoral headRDto (lie center line ofRC, thePedersen femoral Ninety-eight femoral components were placed early follow-up show any significant Dent 49no:87, 1983 7%, grade It in intervals 1]%, and do grade IV inthe 1%use . Sevcntyphy 1987 showed trend toward distal cortical hypertro:was An analysis of5 collar of .titaandDR those with diagnoses ofand ankylosing sponstem) within mm of function thefemoral anatomic side Stern neutral alignment, 3 in vans, and 15 in valgus-The differences withthe the various implant types

Heterotopic Ossification Following Uncemented Total Hip Arthroplasty Effect of the Operative Approach

8 . Galante The need a standardized evalfive percent of the hips had equal leg lengths 10 phy, with theJ :medial andfor lateral corticessystem at thefurprosdylitis alignment and(neutral, diffuse idiopathic varus, valgus) skeletal was hyperostocollar wasresults placedofinside thesurgeryneck in(editorial) 16 hips and on or postoperative weight-bearing protocols .recorded This may. uating total hip J Bone within I cin . thesis tip remaining stable after surgery . Only one Materials and Methods sis Heterotopic .' ossification It hydroxyapatite appears that was agraded mutifactorial using theetiology classifiis the Joint proximomedial neck in 100 hips . Only suggest that augmentation and 12 Surg 67A :51femoral I, 1985 hip9 .showed significant calcar resorption (6 turn) and Fig . .4. Greater trochanter Im VC, Aglictti P elmore al : Radiology of total likely cation of postoperative Brooker et at .' Calcarweight resorption wasdo mea12% Salvati of the EA, stems filled 80% or of the femoral weeks of partial bearing not Clinical Ratings distal cortical hypertrophy, thus behaving more like technique . spheres were imhip replacements . Clio the Orthop 121 :74, 1976 or latsured and the date of its appearance was recorded medullary canal in either anteroposterior provide any discernable advantages . More It has been recently suggested that the probably, incidence. Ninety-five patients planted through the cut sura10.high modulus implantsrereophotogrammeriv . who underwent 112: aprimary Selvik G : Roentgen method though, Using it the indicates Hospital that for clinical Special Surgery evaluation hip and score, plain Three and millimeters of HO or is greater higher following considered uncemented signifieral planes .THAs Femoral cement technique was study satisfacface severity after the stem and the tro- was uncemented were included inttte this and tot' the study of the kinematics of skeletal system 69 hips were rated as excellent, 38 were rated as cant .."Subsidence was measured andoperative the date of its tory in 77% of the hips . In 87% of the hips deemed. radiography lack the the precision required to reliably THA However, approach chanteric wires hadeffect been of an Survivorship reviewed in aAnalysis retrospective fashion . The patients Acta Orthop Scand Suppl 60 :1 . 1989 good, were was rated as fair, 5 were as than poor 3. appearance recorded . and Subsidence greater unsatisfactory, the reason was the presence of less assess prosthetic fixation . Therated stereoradioplaced4. early were dividedB,into two groups based the operative 11 . Mjoberg trancson LL Selvik G : on instability, nugraThe hip scores improved from a preoperative mean mm was considered significant andradiograph interpreted as than 3stern mm of the cement mantle lateral tostem-cement the distal graphic data most precisely reveal prosthetic migraBecause ofin the variable follow-up reFig. 3 . (A) Two-month anieroposterior of aof titanium-alloy a 67-year-old woman . (B?: lengths tion, and laxity of total hip prostheses roentgen sterapproach used . Group I consisted of 52 Aapatients from 17 tion .8 in points all line groups, (range, but 10-29 it points) should he to noted a postoperative that migraported, survivorship analysis was performed (Fig . 4)At. radiolucent gross loosening (dehonding) . Femoral has component developed radiolucent in zone I at 44 months stem after . Eighty-nine surgery . The of patient the hips was were asymptomatic 40 mm offset . (C) and eophotogrammeiric study hiam the Deparbrrervs of''Orlhopaedic .Surgery and tRadiclogv, Tu. Acta Orhop Scand 55 : t41 . the US Naval Hospital (Oakland, CA) who under60 months alter surgery, The stem-cement radiolucent line increased iu width.asand cystic offset cortical erosion 5is mean of 32 .7SdroeI points or and an excellent result . were Pain. relief Failures weremmdefined radiographic evidence ofmm lane lines University (stem-cement of Medicine, hone-cement) New Orleans. Louisiana mea27I has were 45 offset Anatomic within tion rates are unaltered by the presence ofin zone 1984 went 63 noncemented THAs fromrevised 1987 atto7 years 1989. noted Reprint . using Therequests patient Dr has . Robert moderate thigh Department pain of Orthopacnonsteroidal antiinflammatory medication and sured the:augmentation method ofaBarrack, Gruen et al .,'requiring was hydroxyapatite also excellent, with mean or earlier follow-up unprotected score of definite femoral loosening . Survivorship this ceand the date was reproduced in 57 C,ofHansson 81 hipswas in which it 12 . Mjoberg B, Selvik LI(70%) et al for : Mechanical 1430 Tulane Avenue, New Orleans . LA 70112 . using the LSF hipfemoral system within (Implant See9dics-SL32, .2 their compared toweight a preoperative . This mean suggests ofpresence 3 .5 that . Funcenmented titanium component was of appearance was recorded . The and could be assessed, 10Technology, in89 70-of 77 postoperative hearing 3% loosening of total and hip prostheses. Jmm Bone Joint Surg tion improved thedoleast, fromwere a preoperative mean at 4 68B_770, years (95(% confidence interval) location of cement fractures recorded . Possible, hips (91"/o) .1986 There were 92 low neck, 23 medium hanced surfaces not alter femoral component mi.

641