Patient injuries in primary total hip replacement: Nationwide analysis in Finland

Ac a O hopaedica 2016; 87 (3): 209–217 Pa ien inju ies in p ima y o al hip eplacemen Na ionwide analysis in Finland Teemu HELKAMAA 1, Ee o HIRVENSALO 1, 2, Heini HUHTALA 3, and Ville REMES 4 1 Depa men o O hopedics and T auma ology, Helsinki Uni e si y Cen al Hospi al; 2 Pa ien Insu ance Cen e , Helsinki; 3 School o Heal h Sciences, Uni e si y o Tampe e, Tampe e; 4 Pihlajalinna G oup, Helsinki, Finland. Co espondence: [email p o ec ed] Submi ed 2015-03-03. Accep ed 2015-11-09. © 2016 The Au ho (s). Published by Taylo & F ancis on behal o he No dic O hopedic Fede a ion. This is an Open Access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion-Non-Comme cial License (h ps://c ea i ecommons.o g/licenses/by-nc/3.0) DOI 10.3109/17453674.2015.1135662 Backg ound and pu pose — Al hough he esul s o p ima y o al hip eplacemen s (THRs) a e gene ally excellen , some imes se i- ous complica ions a ise. Some o hese se e e complica ions a e conside ed o be pa ien inju ies. We analyzed p ima y THR- ela ed pa ien inju ies in a na ionwide se ing. Pa ien s and me hods — We e alua ed all he p ima y THR- ela ed pa ien inju y claims in Finland be ween 2008 and 2010. We used he o iginal medical eco ds and 2 na ionwide egis ies, he Ca e Regis e o Social Wel a e and Heal h Ca e and he Pa ien Inju y Claim Regis e . Resul s — We iden i i ed 563 claims, 44% o which we e com- pensa ed (n = 250). O hese 250 compensa ed claims, 79% we e conside ed o be a oidable ( ea men inju ies) and 21% we e se e e unexpec ed in ec ions (wi h a p eope a i e in ec ion isk o less han 2%). The mos common ype o echnical e o was cup malposi ion (31%). High- olume hospi als (wi h an annual p ima y THR olume ≥ 400) had a lowe pa ien inju y a e. In lowe - olume hospi als (wi h an annual p ima y THR olume o < 400), he ela i e isks (RRs) o pa ien inju y o any eason, due o echnical e o s, o because o cup malposi ion we e 2- old (95% CI: 1.6–3.1), 4- old (95% CI: 2.3–6.2), and 9- old (95% CI: 3–28), espec i ely, compa ed o high- olume hospi als. In e p e a ion — Ou s udy p o ides he i s comp ehensi e na ionwide da a on THR- ela ed pa ien inju y ypes. Hospi al olume was associa ed wi h he quali y and quan i y o e o s de ec ed. An annual hospi al olume o ≥ 400 p ima y THRs was es ablished as a p o ec i e ac o agains pa ien inju ies. ■ Al hough o al hip eplacemen (THR) is conside ed o be a sa e p ocedu e, ea ly complica ions and e-admission a es om 8% o 10% ha e been epo ed a e p ima y THR (DeHa and Riley 1999, Kha od e al. 2006, Feh inge e al. 2010, Namba e al. 2012, Wol e al. 2012). Mos o hese ea ly complica ions canno be a oided; no do hey lead o sig- ni i can ha m o he pa ien , e.g. supe i cial wound in ec ions (Walmsley e al. 2005). Howe e , some imes se ious and e en a al complica ions a ise (Pa izi e al. 2001, 2007) and some o hese can be conside ed o be pa ien inju ies. Lea ning om acciden s is a widely used co ne s one o sa e y analysis, and in medicine, complica ions a e an impo - an sou ce o in o ma ion. Pa ien inju ies ha e been shown o occu mainly du ing ou ine p ocedu es (Regenbogen e al. 2007) and hey ep esen he mo e se e e end o he spec um o complica ions (May and S engel 1990, Sloan and Hsieh 1995, S udde e al. 2000, Bisma k e al. 2006, Dunba and Sab y 2007). Fo a complica ion o be conside ed a pa ien inju y in he Finnish “no- aul ” insu ance sys em, i mus ul i ll 1 o he 7 compensa ion c i e ia de i ned in he Pa ien Inju y Ac , and he consequences o he claiman mus be su - i cien ly se e e (Table 1). The e o e, only a oidable o su - i cien ly se e e complica ions may quali y as pa ien inju ies. P ima y THR has been he leading cause o pa ien insu - ance claims in Finland o yea s (S a is ics o Finnish Pa ien Insu ance Cen e , 2015). In Finland, pa ien s i le a claim a e THR up o 26 imes mo e a idly han a e hospi aliza ion in gene al (Jä elin e al. 2012). P e ious s udies ha e indica ed ha high- olume hospi als and su geons, con inuous ad ances in in aope a i e ca e, and imp o ed su gical echniques may educe pos ope a i e complica ions, mo bidi y, and mo ali y a e p ima y THR (Pa izi e al. 1999, Ka z e al. 2001, Yasu- gana e al. 2009, Ra i e al., 2014). The pu pose o his s udy was o in es iga e he ypes o inju y, he mechanisms, and he ac o s ha lead o pa ien inju ies a e p ima y THR in a na ionwide se ing. Pa ien s and me hods The pa ien insu ance scheme in Finland (“no- aul ”) No dic coun ies including Finland ha e adop ed a “no- aul ” pa ien insu ance sys em (Mikkonen 2004) based on he con- cep s o “p e en abili y” and “ ole abili y” a he han “neg- Un i led-12.indd 1Un i led-12.indd 1 1/19/2016 7:21:19 PM1/19/2016 7:21:19 PM 209 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 Ac a O hopaedica 2016; 87 (3): 209–217 ligence”, as in he o insu ance sys ems used in he UK and he USA. In Finland, pa ien inju y claims a e esol ed by he Pa ien Insu ance Cen e , and only a ely do hey ad ance o he legal sys em and he cou s. Claims a e handled i less han 3 yea s ha e passed om he momen he pa ien became awa e o he inju y. In i s decision making, he cen e uses ex e nal medical expe s and all a ailable in o ma ion abou he case. Copies o all pa ien documen s a e eques ed om he heal h- ca e ins i u ions in ol ed in he ea men o he claiman . The Pa ien Insu ance Cen e accep s o ejec s claims based on he c i e ia de i ned in he Pa ien Inju y Ac (Jä elin 2012). The main compensa ion c i e ia o ypical THR- ela ed complica- ions a e shown in Table 1. S udy pe iod and egis y sou ces Pa ien inju y claims we e collec ed om he Pa ien Insu - ance Cen e Claim Regis e (see below). The Ca e Regis e o Social Wel a e and Heal hca e (HILMO) was used as a sou ce o pa ien cha ac e is ics o all THR ecipien s (Table 2), and o hospi al p ima y THR olumes (Table 3). The da a we e collec ed om he HILMO be ween 2005 and 2010. The ime pe iod was chosen o ensu e ha he con ol THR ecipien s (“non-claiman s”, Table 2A–C) we e ope a ed on du ing he same ime pe iod as he claiman s due o he allowed 3-yea delay in claim i ling (see abo e). Al oge he , 93% o pa ien inju y claiman s who i led a claim in he pe iod 2008–2010 had hei p ima y ope a ion be ween 2005 and 2010. The 3-yea a e age hospi al olumes we e used in he RR analy- ses, as he pa ien inju ies we e also collec ed om he 3-yea ime pe iod. Pa ien Insu ance Cen e da a collec ion Da a on all pa ien s who had i led a claim ela ing o p i- ma y THR su ge y in Finland be ween Janua y 1, 2008 and Decembe 31, 2010 we e collec ed om he claim egis e o he Pa ien Insu ance Cen e . Claims ela ed o p ima y THR wi h su gical p ocedu es NFB30–62 acco ding o he No dic Medico-S a is ical Commi ee’s classi i ca ion o su gical p o- cedu es (NCSP) we e included in he s udy. Pa ien s who had hip ac u e as a cause o THR we e excluded (Figu e 1). The o iginal pa ien documen s, adiog aphs, and claim decisions we e e iewed (by TH) and analyzed. The in o ma ion and a iables collec ed included pa ien cha ac e is ics (age, sex, diagnoses), he hospi al, and de ailed cha ac e is ics o he ope a ions (ope a ed side, su gical app oach, su geon’s expe- ience, and ype o implan (cemen ed s. cemen less)). Ca ego iza ion o hospi al olume Hospi als pe o ming p ima y THRs in Finland we e ca ego- ized in o 4 g oups acco ding o he a e age annual olume o each hospi al be ween 2005 and 2010. O e all, 67 hospi als we e g ouped based on olume as ollows: < 100 (g oup 1), 100–199 (g oup 2), 200–399 (g oup 3), and ≥ 400 (g oup 4). G oup 4 hospi als (la e e e ed o as “high- olume cen e s”) we e used as he e e ence g oup in he ela i e isk (RR) anal- yses in Table 3, o in es iga e he e ec o hospi al olume on ypes o pa ien inju y. O he hospi al g oups we e also com- pa ed wi h each o he (Table 3). No uni o m ca ego iza ion o hospi al olume exis s in he li e a u e. The high- olume g oup 4 hospi als we e all uni e si y eaching hospi als. Analysis o associa ed ac o s We in es iga ed how di e en ac o s (age, sex, p ima y diag- nosis, ope a ion ype, and annual p ima y THR olume o he ope a ing hospi al) we e associa ed wi h claim i ling and claim Table 1. Compensa ion c i e ia Main c i e ia a: Compensa able i : T ea men inju y An expe ienced clinician would ha e ac ed di e en ly and hus a oided he se e e ha m and/o inju y o he pa ien . In ec ion inju y Based on pa ien ’s como bidi ies and medica ions, he p eope a i e in ec ion isk is below 2% and he consequences o he pa ien a e su i cien ly se e e. Un easonable inju y A se e e inju y ha led o pe manen ha m o dea h and was unp edic able judging by he illness and heal h s a us in gene al and he heal hca e o medical ca e gi en. Speci i c ea men inju y e en s: Compensa able i b: Pos ope a i e in ec ion The pa ien has su e ed a DSSI ha has led o se e e consequences e.g. (1–) 2 subsequen eope a ions/ e isions o pe manen emo al o he implan (Gi dle- s one p ocedu e) and p olonged a e ca e. Cup o s em malposi ion Componen malposi ioning leading o sig- ni i can clinical symp oms/ad e se e en leading o eope a ion(s). Could ha e been a oided wi h mo e ca e ul su gical execu- ion. Cup o s em ins abili y Componen ins abili y could ha e been a oided wi h mo e ca e ul su gical execu- ion, and has led o a eope a ion. Leg leng h disc epancy Unplanned pos ope a i e leg leng h dis- c epancy o mo e han 1.5 cm. F ac u e The ac u e has been o e looked du ing he ope a ion o he os eosyn hesis has been inadequa e. Ne e o ascula inju y Inabili y o p o ec he su ounding ne es o ascula u e du ing he ope a ion (e.g. documen ed di ec inju y, inabili y o loca e and p o ec he ischias ne e when using pos e ola e al app oach, unin en ional leg leng h disc epancy leading o pa esis, se e e ascula inju y). Delay in ea men A delay ha has led o he se e e ha m/ inju y o he pa ien . Insu i cien diagnos ics Some signi i can clinical o adiological i ndings ha e been o e looked o misdiag- nosed, leading o se e e ha m/inju y o he pa ien . a De i ned in de ail in he Pa ien Inju y Ac (Jä elin e al. 2012). b Each claim is e alua ed indi idually; hus, he c i e ia he e a e di ec ional. DSSI: deep su gical si e in ec ion. Un i led-12.indd 2Un i led-12.indd 2 1/19/2016 7:21:19 PM1/19/2016 7:21:19 PM 210 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 decisions. We also de e mined whe he pa ien s ope a ed on in a ious olume hospi als di e ed ega ding hese ac o s. Classi i ca ion o compensa ed ea men inju ies The Pa ien Inju y Ac ca ego izes all compensa ed claims in o 7 classes. We di ided he ea men inju ies in o 6 sub- classes, which we e u he analyzed and di ided acco ding o he ype o e o o he inju y mechanism. The classi i ca ion o compensa ed pa ien inju ies is shown in Figu e 2. S a is ics Unless o he wise s a ed, analyses we e conduc ed using he chi-squa e es . Logis ic mul i a ia e eg ession models we e used when pa ien -speci i c a iables we e a ailable, and hey we e es ed using STATA 12 so wa e. S a is ical signi i cance was se a an alpha le el 0.05. Rela i e isk and 95% con i - dence in e als (CIs) we e calcula ed acco ding o Ga dne and Al man (1994). G oup 4 hospi als we e used as he e e ence g oup in RR calcula ions. The numbe o ea men s needed o cause a compensa able echnical e o o lowe - olume hos- Common p oblems aised by claiman s we e pain and/o dis- sa is ac ion wi h he unc ion o he a i i cial hip join . One o bo h we e add essed in he majo i y o he claims associa ed wi h ea men inju ies. Some o he speci i c clinical p oblems epo ed by claiman s in hei claims included in ec ions (n = 121), ne e damage (n = 111), leg leng h disc epancy (n = 85), ac u e ea men (n = 55), disloca ion (n = 41), and delay in ea men (n = 17). The compensa ion a es o hese we e as ollows: in ec ions 44%, ne e damage 36%, leg leng h dis- c epancy 28%, ac u e ea men 20%, disloca ions 71%, and delays in ea men 35%. Pa ien - ela ed and ope a ion- ela ed a iables asso- cia ed wi h pa ien inju ies THR ecipien s we e mo e inclined o i le a claim i hey we e unde 65 yea s o age, i hey we e ope a ed wi h ully cemen less implan s, o i hey we e ope a ed in hospi als ha pe o med less han 400 p ima y THRs annually (Table 2A–C). In ec ion claiman s we e also mo e o en males and mo e o en ope a ed in g oup 1–3 hospi als (Table 2B). Com- pi als (g oups 1–3) was calcula ed based on absolu e isk educ ion (Cook and Sacke 1995, Bende 2001). E hics Pe mission o ca y ou he s udy was ob ained om he Finnish Minis y o Social A ai s and Heal h (STM/4724/2011). The s udy was conduc ed acco ding o he Dec- la a ion o Helsinki. Da a handling was pe - o med acco ding o Finnish da a p o ec ion legisla ion. Resul s Du ing he s udy pe iod, 563 THR- ela ed claims we e esol ed by he Pa ien Insu - ance Cen e (Figu e 1). The incidences o all i led claims and o i led in ec ion claims du ing he s udy pe iod we e 2.6% and 0.6%, espec i ely. O all he claims i led, 44% we e compensa ed (Figu e 2). O all he compensa ed claims, 79% we e ea - men inju ies and 21% we e in ec ion inju- ies (Figu e 2). The incidences o compen- sa ed claims and o compensa ed in ec ions we e 1.2% and 0.2%, espec i ely. The o e all isk o pa ien inju ies was lowe o pa ien s who we e ope a ed on in high- olume hospi als (G oup 4) (Table 3). Pa ien - epo ed easons o i ling a claim Figu e 1. Flow cha o da a collec ion. NFB: any p ima y hip a h oplas y ope a ion; NFC: any hip e ision ope a ion; NFJ: any hip ac u e ope a ion; NGB: any p ima y knee a h oplas y; NGC: any e ision knee a h oplas y. a 2 claims o 10 we e om high- olume hospi als (g oup 4). 9 claims we e ea men inju y claims, and 1 was an in ec ion claim (g oup 3). Insu ance claims eco ded as p ima y THA (NFB30–62) n = 590 Compensa ed p ima y THR claims n = 264 Non-compensa ed claims n = 326 Excluded (n = 39): – Ope a ion because o hip ac u e (n = 20) – Regis y e o s (n = 9) – O iginal pa ien eco ds una ailable o decision pending (n = 10) b Included compensa ed p ima y THR claims n = 250 T ea men inju ies n = 197 In ec ion inju ies n = 53 Included ( egis y e o s) n = 12 All pa ien inju y claims in Finland associa ed wi h hip su ge y (NFB a , NFC a , NFJ a ) be ween yea s 2008 and 2010 n = 934 O he han NFB30–62 n = 344 Non-compensa ed pa ien inju y claims n = 313 n = 26 Reco ded as compensa ed n = 141 Claims egis e ed wi h su gical codes NGB a o NGC a (n = 641) n = 13 Un i led-12.indd 3Un i led-12.indd 3 1/19/2016 7:21:19 PM1/19/2016 7:21:19 PM 211 Ac a O hopaedica 2016; 87 (3): 209–217 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 Compensa ed pa ien inju ies (n = 250) T ea men inju ies (n = 197) In ec ions (n = 53) Unjus ified ope a ion (n = 5) Pe iope a i e echnical e o s (n = 189) Cup side e o s (n = 80) O he e o s (n = 28) Inadequa e ac u e ea men (n = 22) Mul iple e o s (n = 36) d • Ins able implan • Malposi ion Classifica ion o compensa ion c i e ia based on Pa ien Inju y Ac (n = pa ien s) De ailed g ounds o compensa ions (n = pa ien s) T ea men delay o insu icien a e ca e (n = 9) Technical e o ype (n = pa ien s) • Missed ac u e in aope a i ely • Inadequa e os eosyn hesis • Di ec inju y e.g. cu , su u e, blun auma • Ne e no iden ified using pos e ola e al app oach • Dis ension e.g. leg leng h disc epancy • Unclea mechanism 21% 79% 96% 3% 5% 42% 12% 15% Mul iple g ounds (n = 10) 5% • Cemen ing p oblems • Inadequa e closu e •Incompa ible componen s S em side e o s (n = 54) 29% 10 % b Leg leng h disc epancy (n = 19) c • Ins able implan • Malposi ion 19% 2% Insu icien diagnos ics (n = 4) 23% De ailed mechanisms o inju ies Failu e o p o ec he su ounding s uc u es (n = 43) a Figu e 2. Types o pa ien inju y. a Ne e o ascula lesions/inju ies. b Pe cen age (%) o all pe iope a i e echnical e o s. c Unplanned leg leng h di e ence o > 2 cm due o s em malposi ion. d Two pa ien s had 3 e o s. Table 2. Pa ien and ope a ion cha ac e is ics (exp essed as %) Age Sex Diagnosis Ope a ion Hospi al olume n ≥ 65 < 65 Men Women POA a O he NFB30 b O he ≥ 400 < 400 A Non-claiman s 42,579 58 42 44 56 86 14 52 48 33 67 All claiman s 563 52 48 43 57 86 14 58 42 21 79 p- alue 0.005 c 0.6 0.6 0.005 c < 0.001 c B Non-claiman s 43,021 58 42 44 56 86 14 52 48 33 67 In ec ions 121 57 43 61 39 89 11 54 46 23 77 p- alue 0.9 < 0.001 c 0.4 0.8 0.03 c C Non-claiman s 42,700 58 42 44 56 86 14 52 48 33 67 T ea men inju ies 442 47 53 38 62 85 15 60 40 21 79 p- alue < 0.001 c 0.01 c 0.3 0.002 c 0.001 c D Denied 313 50 50 41 59 84 16 58 42 24 76 Compensa ed 250 48 52 45 55 87 13 58 42 18 82 p- alue 0.2 0.3 0.3 1.0 0.05 E < 400 (g oup 1–3) 443 52 48 44 56 88 12 58 42 … … ≥ 400 (g oup 4) 120 50 50 40 60 76 24 58 42 … … p- alue 0.4 0.4 < 0.001 c 0.5 The pa ien and ope a ion cha ac e is ics o o al hip eplacemen (THR) ecipien s in Finland be ween 2005 and 2010 a e p esen ed as pe cen ages o all in he g oup. Pa ien s we e cha ac e ized based on age, sex, and diagnosis. Ope a ions we e cha ac e ized based on ope a ion ype and hospi al olume. Lines A, B, and C show he compa ison o a iables associa ed wi h claim i ling among all claiman s, in ec ion claiman s, and ea men inju y claiman s compa ed o all THR ecipien s who did no i le a claim (“non-claiman s”). Rows ma ked D show a compa ison o he cha ac e is ics o denied and compensa ed claiman s. Rows ma ked E show he cha ac e is ics o pa ien s who we e ope a ed in high- olume hospi als (g oup 4) and lowe - olume hospi als (g oups 1–3). a P ima y os eoa h osis (POA). b Cemen less THR based on NOMESCO classi i ca ion o su gical codes. c S a is ically signi i can . Calcula ed using chi-squa e es . Any p- alues < 0.05 we e conside ed s a is ically signi i can . Un i led-12.indd 4Un i led-12.indd 4 1/19/2016 7:21:20 PM1/19/2016 7:21:20 PM 212 Ac a O hopaedica 2016; 87 (3): 209–217 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 pa ed o g oup 4 hospi als, o THR ecipien s who we e ope - a ed in g oup 1–3 hospi als, he RRs o i ling a claim o any eason—due o in ec ion o due o ea men inju y—we e 1.8 (CI: 1.5–2.2), 1.6 (CI: 1.1–2.4), and 1.8 (CI: 1.5–2.3), espec- i ely (Table 3). None o he a iables we e associa ed wi h Pa ien Insu ance Cen e claim decisions (Table 2D). Since a highe p opo ion o denied claims in g oup 4 hospi als was no ed (p = 0.05), a mul i a ia e logis ic eg ession model anal- ysis was also conduc ed. Analysis showed only a end (odds a io (OR) = 1.5, CI: 0.97–2.3; p = 0.07). Pa ien s ope a ed in high- olume cen e s (g oup 4) we e o he wise simila o THR ecipien s ope a ed in lowe - olume hospi als (g oups 1–3) o all pa ien - ela ed and ope a ion- ela ed cha ac e is- ics, bu s a is ically signi i can ly mo e pa ien s wi h second- a y causes o os eoa h i is we e ope a ed on in high- olume cen e s (g oup 4) han in g oup 1–3 hospi als (Table 2E). Types o inju y Compensa ed THR- ela ed pa ien inju ies we e di ided in o 2 ca ego ies: ea men inju ies and in ec ion inju ies (Figu e 2 and Table 3). T ea men inju ies and echnical e o s On a e age, e e y 109 h and 140 h THR esul ed in compen- sa ed ea men inju y and compensa ed in aope a i e echni- cal e o , espec i ely. In aope a i e echnical e o s we e he single mos equen ly compensa ed ype o ea men inju y de ec ed. Malposi ion o he cup was he mos common ype o in aope a i e echnical e o (31%) based on he Insu ance Cen e expe e alua ions. Almos hal (47%) o pa ien s wi h cup malposi ion had disloca ion a e hei p ima y ope a- ion and 85% o compensa ed claiman s wi h disloca ion had a malposi ioned cup. Malposi ion o he s em was he mos common compensa ed e o on he emo al side. I accoun ed o 61% o s em-side echnical e o s, 58% o which esul ed in leg leng h disc epancy. Inabili y o p o ec he su ound- ing ne es and blood essels was a eason o compensa ion in 43 echnical e o claims (22%). 3 o hese we e ascula inju ies, all o which we e ope a ed on using he an e ola e al (Ha ding) app oach. O all ne e inju ies, a di ec inju y was de ec ed in one- hi d o cases. O all claiman s compensa ed o ne e inju ies, wo- hi ds had been ope a ed on ia he pos e ola e al app oach. Table 3. The ela i e isks (RRs) o claims, pa ien inju ies, and speci i c echnical e o ypes in G oups 1–3 wi h G oup 4 as e e ence g oup Hospi al g oup (annual olume) a All G oup 4 (≥ 400) G oup 3 (200–399) G oup 2 (100–199) G oup 1 (< 100) n = 21,571 b n = 7,032 b n = 3,525 b n = 6,326 b n = 4,688 b n n n RR (95% CI) n RR (95% CI) n RR (95% CI) Risks o i led claims: All 563 120 98 1.6 (1.3–2.1) d 205 1.9 (1.5–2.4) d 140 1.8 (1.4–2.2) d In ec ion 121 28 18 1.3 (0.7–2.3) 47 1.9 (1.1–3.0) d 28 1.5 (0.9–2.5) T ea men inju y 442 92 80 1.7 (1.3–2.3) d 158 1.9 (1.5–2.5) d 112 1.8 (1.4–2.4) d Risks o compensa ed claims: All 250 44 40 1.8 (1.2–2.8) d 106 2.7 (1.9–3.8) d,e 60 2.1 (1.4–2.4) d In ec ion (in ole able inju y) 53 12 6 1.0 (0.4–2.7) 23 2.1 (1.1–4.3) d 12 1.5 (0.7–3.3) T ea men inju y (a oidable inju y) 197 32 34 2.1 (1.3–3.4) d 83 2.9 (1.9–4.3) d 48 2.3 (1.4–3.5) d Risks o speci i c a oidable inju ies: Any echnical e o 189 30 31 2.1 (1.3-3.4) d 83 3.1 (2.0-4.7) d 45 2.3 (1.4-3.6) d Any cup-side e o 80 6 14 4.7 (1.8–12) d 40 7.4 (3.1–18) d 20 5.0 (2.0–12) Cup malposi ion 58 3 9 6.0 (1.6–22) d 29 11 (3.3–35) d 17 8.5 (2.5–29) d Any s em-side e o 54 10 7 1.4 (0.5–3.7) d 23 2.6 (1.2–5.4) d 14 2.1 (0.9–4.7) d S em malposi ion 33 6 3 1.0 (0.3–4.0) 15 2.8 (1.1–7.2) d 9 2.3 (0.8–6.3) d Ins able implan 44 7 9 2.6 (1.0–6.9) 19 3.0 (1.3–7.2) d 9 1.9 (0.7–5.2) Implan malposi ion 99 11 12 2.2 (1.0–4.9) 47 4.8 (2.5–9.2) d, 29 4.0 (2.0–7.9) d Ne e and ascula inju ies 43 13 7 1.1 (0.4–2.7) 16 1.4 (0.7–2.8) 7 0.8 (0.3–2.0) Leg leng h disc epancy 19 6 3 1.0 (0.3–4.0) 8 1.5 (0.5–4.3) 2 0.5 (0.1–2.5) F ac u e ea men 22 2 4 4.0 (0.7–23) 8 4.5 (0.9–21) 8 6.0 (1.3–28) d O he su gical e o s c 29 1 5 10 (1.2–85) d 9 10 (1.3–79) d 14 21 (2.8–160) d Mul iple echnical e o s 34 1 5 10 (1.2–85) d 12 12 (1.6–95) d 16 22 (3.0–170) d Table shows he ela i e isks (RRs) and 95% con i dence in e als (CIs) when g oup 4 hospi als we e he e e ence g oup (RR = 1.00). No signi i can di e ences be ween g oup 1 and g oup 3 hospi als o be ween g oup 1 and g oup 2 hospi als we e de ec ed. a A e age annual p ima y THR olume o each hospi al in he g oup. b 3-yea a e age olume o all hospi als in he g oup calcula ed be ween he yea s 2005 and 2010. c Compensa ed e o s associa ed wi h closu e, cemen ing, d ain pipe emo al, ailu e o emo e os eophy es, un ounded use o special implan s, o use o non-compa ible componen s. d S a is ically signi i can alues compa ed o ≥ 400 hospi als. e and show he s a is ically signi i can alues compa ed o g oup 3 hospi als (RR o g oup 3 = 1.00). e RR = 1.5 (95% CI: 1.0–2.1). RR = 2.2 (95% CI: 1.2–4.1). Un i led-12.indd 5Un i led-12.indd 5 1/19/2016 7:21:20 PM1/19/2016 7:21:20 PM 213 Ac a O hopaedica 2016; 87 (3): 209–217 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 In ec ion inju ies All compensa ed in ec ion inju ies (n = 53) we e deep su gical si e in ec ions. The RR o i ling a claim because o in ec ion was highe in males (RR = 1.6, CI: 1.0–2.4) (Table 2) and in pa ien s who we e ope a ed on in g oup 1–3 hospi als (Table 3). Compa ed o high- olume cen e s, he isk o in ec ion inju ies ha we e compensa ed was s a is ically signi i can ly highe in g oup 2 hospi als only (Table 3). Fac o s associa ed wi h pa ien inju ies Hospi al olume. An annual hospi al olume abo e 400 p i- ma y THRs was associa ed wi h ewe i led claims, ewe compensa ed claims, and ewe compensa ed echnical e o s (Figu e 3 and Table 3). High- olume cen e s (g oup 4) pe o med 34% o all THRs in Finland. E en so, hese hospi als accoun ed o only 21% o he i led claims and o 18% o he compensa ed pa ien inju- ies (Figu e 3A). Fo pa ien s who we e ope a ed on in g oup 1–3 hospi als, he RR o compensa ions o any eason we e inc eased o e 2- old (RR = 2.3, CI: 1.6–3.1), and o ech- nical e o s almos 3- old (RR = 2.6, CI: 1.7–3.8) (Table 3). The numbe needed o ea o cause an unnecessa y compen- sa able in aope a i e echnical e o o lowe - olume hospi- als (g oups 1–3) was 150 (CI: 112–228), meaning ha e e y 150 h THR pe o med in lowe - olume hospi als esul ed in a pa ien inju y ha could ha e been a oided by ope a ing he pa ien in a high- olume join cen e (g oup 4). The quali y o echnical e o s was also di e en depend- ing on he hospi al olume (Table 3). Pos ope a i e leg leng h disc epancy and in aope a i e ne e damage we e he only a oidable e o ypes de ec ed a a simila a e in all hospi als. In g oup 4 hospi als, howe e , hese 2 e o ypes accoun ed o 60% o all compensa ed echnical e o s, whe eas in g oup 1–3 hospi als he co esponding pe cen age was 23%. Ins ead, he isk o echnical e o s classi i ed as “o he e o s” was 13 (CI: 2–96) imes highe o pa ien s who we e ope a ed on in g oup 1–3 hospi als a he han g oup 4 hospi als (Table 3). Su geons Compensa ed in aope a i e echnical e o s (n = 189) we e dis ibu ed among 112 su geons. 2 su geons wi h he mos pa ien inju ies had ope a ed on 8% o all pa ien s who we e compensa ed due o echnical e o s. Only 9 su geons had mo e han 1 compensa ed echnical e o pe yea . These 9 su geons had ope a ed on 24% o all claiman s who we e compensa ed due o echnical e o s, and hey p oduced 53% mo e compensa ed echnical e o s han all g oup 4 hospi als oge he . Some o hese 9 su geons ope a ed in se e al di e - en hospi als. The indi idual THR olumes o Finnish o ho- pedic su geons a e no a ailable in any egis e . Thus, o mini- mize he possibili y ha a small numbe o su geons migh explain he associa ion de ec ed be ween hospi al olume and pa ien inju ies, we excluded all 9 su geons wi h mo e han one echnical e o pe yea om he hospi al olume e ec calcula ions. A e his exclusion, he isk o compensa ion in g oup 1–3 hospi als o any eason was s ill o e 2- old (RR = 2.2, CI: 1.5–3.3), and o echnical e o s almos 3- old (RR = 2.9, CI: 1.7–4.9), compa ed o ha o high- olume join cen e s (Table 3). Figu e 3. Hospi al olume and pa ien inju ies. A. The associa ion be ween high THR olume and lowe incidence o claims i led, compensa ed claims, and pe iope a i e echnical e o s. B. The numbe o compensa ed claiman s wi h a oidable ech- nical e o s in each indi idual hospi al pe o ming o al hip eplacemen s (THRs) ela i e o hospi al olume. Hospi als wi h o e 50 p ima y THRs pe yea we e included. The hick ed line ep esen s he a e age a e o compensa ed claiman s wi h pe iope a i e echnical e o s in Finnish hospi als. Hospi als below he line pe o med be e han he na ional a e age. 0 10 20 30 40 50 60 THRs pe o med a (n = 43,142) (n = 563) Claims filed Compensa ed claims (n = 250) Pe iope a i e echnical e o s (n = 189) Pe cen age o o al o each a iable <100 (G oup 1) 100–199 (G oup 2) 200–399 (G oup 3) ≥400 (G oup 4) AB 0 5 10 15 20 25 30 35 0 200 400 600 800 1000 1200 Numbe o claiman s wi h compensa ed pe iope a i e echnical e o s A e age annual numbe o p ima y THRs pe o med A e age e o a e Un i led-12.indd 6Un i led-12.indd 6 1/19/2016 7:21:20 PM1/19/2016 7:21:20 PM 214 Ac a O hopaedica 2016; 87 (3): 209–217 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 Discussion Complica ions a e impo an ou come measu es o he quali y o medical ca e. Pa ien inju ies a e usually a oidable compli- ca ions due o echnical e o s o unexpec ed in ec ions, and be e ep esen he mo e se e e end o he spec um o com- plica ions. To ou knowledge, he p esen s udy is he i s o p o ide a comp ehensi e na ionwide analysis o THR- ela ed pa ien inju ies, using he o iginal pa ien eco ds. Almos 80% o he pa ien inju ies in Finland we e caused by a oidable e o s ( ea men inju ies). The a e age inci- dence o compensa ed ea men inju ies was 1 inju y pe 109 THRs. The as majo i y o hese we e in aope a i e echni- cal e o s, o which cup malposi ion was he mos common ype o e o . Acco ding o a egis y analysis o almos 180,000 e isions, disloca ions and echnical e o s a e mainly ela ed o inco ec o ien a ion o he implan and he second leading cause o e isions in Sweden (a e asep ic loosening) (Malchau e al. 2002). Ano he s udy moni o ing he quali y o THR ound ha app oxima ely 25% o all THRs ailed due o ac o s ela ed o echnical e o s (Biau e al. 2011). The ypes o inju y and hei equencies ound in he p esen s udy we e also e y simila o hose epo ed ea lie o closed mal- p ac ice claims o THR ecipien s in he USA (Ma sen e al. 2013). Ace abula -side e o s ha e p e iously been shown o accoun o hal o all echnical e o s in THRs (Biau e al. 2009, 2011), and up o 60% o ace abula componen s ha e been shown o be in a subop imal posi ion, depending on he a ge anges used (Ba ack e al. 2013, Lee e al. 2014). Ou esul s a e in line wi h he li e a u e. Wha ou s udy adds o his knowledge is ha echnical e o s a e a clinically impo - an sou ce o se e e complica ions (pa ien inju ies) and ha hey a e associa ed wi h he THR olume o he hospi al. The o e all isk o pa ien inju y a e THR was lowe in hospi als wi h an annual olume abo e 400 THRs despi e he ac ha pa ien s ope a ed in hese hospi als mo e o en had seconda y causes o os eoa h i is and he e o e a highe deg ee o su gical complexi y. The e was also a di e ence in he quali y o he e o s de ec ed be ween high- olume hos- pi als and lowe - olume hospi als. I has been epo ed p e- iously ha high- olume su geons and hospi als ha e less complica ions in p ima y THR su ge y (La e nia and Guzman 1995, K ede e al. 1997, 1998, No on e al. 1998, Ba aglia e al. 2006, Ra i e al. 2014). One explana ion o his migh be he be e ou ines o highly specialized su geons and s a in high- olume cen e s. The e we e also hospi als o g oups 1–3 wi h a low incidence o pa ien inju ies. The ela i ely sho s udy pe iod and also chance may pa ly explain his. I migh also be ha he quali y o pe o mance in some o hese hospi als is a same le el as in he high- olume cen e s. A small g oup o o hopedic su geons (n = 9) pe o med 24% o all he THRs wi h epo ed compensa ed echnical e o s in Finland, and p oduced o e 50% mo e echnical e o s han he 4 la ges join cen e s pu oge he . Al hough we we e no able o analyze he indi idual su geon olumes, his g oup o su geons wi h he mos echnical e o s does no explain he associa ion be ween lowe hospi al olume and highe inci- dence o pa ien inju ies. When hese 9 su geons we e ana- lyzed mo e closely, i was no ed ha some ope a ed in di e - en hospi als and ha some we e he heads o hei o hopedic depa men s. Bo h o hese i ndings highligh essen ial l aws in he cu en supe iso y p ocess. When sel -e alua ion is p ac iced o when heads o o hopedic depa men s who a e esponsible o supe ision a e only awa e o wha happens in hei own hospi al, i is i ually impossible o con ol and elimina e hese isk ac o s. Be e coo dina ion and co ec i e measu es in he hospi als by he hospi al adminis a ion—o es ablishmen o a na ionwide supe ision body ocusing on benchma ked pe o mance s anda ds—would he e o e be bene i cial. A public egis e and open epo ing o hospi al- and su geon-le el pe o mance in a way ha he Na ional Ins i u e o Heal h and Ca e Excellence (NICE) in he UK ope a es would be a aluable ool o his kind o supe iso y body, enhancing sa e y and imp o ing pa ien ca e in endo- p os he ic su ge y. When conclusions a e being d awn om s udies in es i- ga ing pa ien inju ies, one has o ake in o accoun ha he spec um o complica ions de ec ed is somewha skewed, since a la ge p opo ion o ad e se e en s a e nei he com- pensa able no a oidable, e.g. supe i cial in ec ions (Walms- ley e al. 2005). Fu he mo e, only some o all he complica- ions quali y as pa ien inju ies—and hese ep esen he mo e se e e end o he spec um o complica ions. Ou s udy he e- o e highligh s wha kinds o a oidable se e e complica ions occu a e THR. Also, epo ing bias has o be accoun ed o . I has been sugges ed ha only 3% o all pa ien s who a e eli- gible o compensa ion (se e e complica ions) e e i le claims (S udde e al. 2000, Bisma k e al. 2006, Jä elin 2012). The a e age a e o pa ien inju y claims a e hospi aliza- ion a ies be ween 0.1% and 0.3% (Pukk e al. 2003, Jä elin 2012). In he p esen s udy, 2.6% o all THR ecipien s i led a pa ien inju y claim and 1.2% we e compensa ed. The inci- dences we e simila o hose no ed ea lie in Finland, be ween 1998 and 2003 (Jä elin e al. 2012). This shows ha THR ecipien s i le pa ien inju y claims up o 26 imes mo e o en han pa ien s in gene al a e hospi aliza ion. A he same ime, he claim ejec ion a e among THR ecipien s is simila o he a e age claim ejec ion a e in he Pa ien Insu ance Cen e . I is he e o e clea ha he THR- ela ed pa ien inju ies ha a e compensa ed (1.2%) ep esen mo e han 3% o se e e com- plica ions, because se e e complica ions ha a e eligible o compensa ion a e no expe ienced by 40% o THR ecipien s. This be e co e age is mos likely due o he subs an ially highe claim a e de ec ed among THR ecipien s. Al hough many complica ions a e no epo ed, he mechanisms behind he ad e se e en s epo ed a e mos likely simila o hose behind complica ions in gene al (Jä elin 2012). S udies in es iga ing pa ien inju ies a e he e o e an impo an sou ce Un i led-12.indd 7Un i led-12.indd 7 1/19/2016 7:21:21 PM1/19/2016 7:21:21 PM 215 Ac a O hopaedica 2016; 87 (3): 209–217 Downloaded by [Tampe e Uni e si y] a 02:28 23 May 2016 o in o ma ion abou he ac o s and mechanisms behind he se e e complica ions in THR. S eng hs and limi a ions The s eng hs o ou s udy included he la ge pa ien coho and he p ospec i ely collec ed egis y da a. We used 2 com- p ehensi e na ionwide egis e s in he da a collec ion and in he analyses. Pa ien inju y claims we e collec ed om he egis y da a o he Pa ien Insu ance Cen e , which manages all pa ien inju y claims in Finland. Each pa ien inju y claim and decision (including pa ien eco ds and adiog aphs) was indi idually assessed by a specialis in he i eld o endop os- he ic su ge y (TH). In Finland, ope a i e ea men s in hospi- als a e hea ily subsidized, wi h ew socioeconomic ba ie s, esul ing in na ional egis y da a ha is highly gene alizable. The no- aul insu ance sys em also limi s socioeconomic ba - ie s, as claim i ling and handling a e always ee o cha ge o claiman s. We combined se e al di e en da a sou ces, which has been sugges ed o u he s eng hen he gene alizabili y o pa ien inju y s udies (Jä elin 2012). Al hough Finland and o he No dic coun ies use he no- aul insu ance sys em, many o he coun ies ely on o sys ems. This migh a ec he gene alizabili y o hese esul s beyond No dic coun ies. Howe e , a ecen s udy om he USA (Ma sen e al. 2013) ound simila echnical e o ypes and a es in THR o hose in ou s udy. High- olume hospi als (g oup 4) had less pa ien inju ies. Se e al di e en a iables such as pa ien awa eness, age, sex, and socioeconomic s a us may a ec he likelihood ha a pa ien will i le a claim a e an ad e se e en (S ud- de e al. 2000, Bisma k e al. 2006, Dunba and Sab y 2007). None o he a iables in es iga ed explained he be e pe o - mance o high- olume cen e s. I has also been sugges ed ha hospi al cul u e (ac i e in o ma ion on pa ien insu ance) and pa ien awa eness ha e an in l uence on he likelihood ha a pa ien will i le a claim. This is undoub edly ue; howe e , he di e ences be ween indi idual hospi als will mos likely be e ened ou in a na ionwide s udy. The e was a end ha claims by THR ecipien s om lowe - olume hospi als (g oups 1–3) we e mo e o en accep ed. This migh be explained by he di e ence in he quali y o e o s be ween high- olume join cen e s and o he hospi als. Finally, we lack in o ma ion on he su ge y olumes o indi idual su geons, which has been associa ed wi h complica ion a es a e THR. Un o una ely, hese da a we e no a ailable in any egis ies. Thus, we could no de e mine how su geon olume ela es o pa ien inju ies in THR. In con as , in Finland hospi al olumes gi e an indi- ca ion o he olumes o su geons ope a ing in hose hospi als because, as a ule, su geons a ely ope a e in mo e han one hospi al. Conclusion This is he i s na ionwide s udy o in es iga e THR- ela ed pa ien inju ies in de ail. We ha e p esen ed he ypes and e- quencies o se e al complica ions, ad e se e en s, and ypical a oidable echnical e o s leading o pa ien inju ies. We ha e also shown ha a high annual hospi al olume (abo e 400 THRs) is associa ed wi h a lowe incidence o i led claims, pa ien inju ies, and a oidable echnical e o s. In Finland, all high- olume hospi als a e uni e si y hospi als. Indi idual su - geons play a key ole in educing a oidable pa ien inju ies in THR. These i ndings p o ide impo an new in o ma ion o conside ing p e en i e measu es agains he complica ions and pa ien inju ies in p ima y THR su ge y. In some coun- ies, he THR pe o mance o hospi als is epo ed and pub- lished so ha anyone can ollow he pe o mance o one hos- pi al and compa e i wi h ha o o he hospi als. These kinds o well-main ained egis y could also gi e in o ma ion abou he indi idual su geon’s pe o mance, a leas o su geons hemsel es, and migh imp o e pa ien ca e. Awa eness o he usual e o s ela ed o THR and he causes o pa ien inju ies should lead o imp o ed pa ien sa e y h ough imp o ed sys- ems o ca e. All he au ho s con ibu ed o he concep ion and design o he s udy, o c i i- cal analysis o he da a, o in e p e a ion o he i ndings, and o c i ical e i- sion o he manusc ip . The au ho s w o e he manusc ip oge he . HH and TH pe o med he s a is ical analysis. We hank Reima Palonen and Saija Leh inen o he Pa ien Insu ance Cen e o hei in aluable assis ance and help. 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