Shoulder arthroplasty surgery has shown remarkable progress during the last few decades. A number of factors affect postoperative range of motion, pain and prosthetic durability. Among these factors, the length of the lever arm and joint stability is the ones that can be altered by the selected prosthetic component. It is uncertain how much of the normal anatomy needs to be re-established. Stemless prostheses with total reliance on metaphyseal fixation were introduced in France in 2004 (TESS, Zimmer Biomet). The goals were to avoid stem-related complications. Stemless implants have other potential benefits, including the ability to restore shoulder anatomy. Study I: This is a prospective cohort study of 49 patients with one of two versions of the TESS prosthesis (anatomical or reverse) with clinical and radiological follow-up ranging from 9–24 months. The TESS prosthesis showed short-term results that were comparable with other shoulder prosthetic systems. Study II: This is a prospective comparative non-randomised study of 37 patients (40 shoulders) who underwent TESS reverse shoulder arthroplasty (RSA) with a follow-up ranging from 15–66 months. We found a significant improvement in functional outcome and reduction of pain in both stemmed and stemless groups. Glenoid overhang influenced the occurrence of scapular notching (SN). Study III: This is a radiological study showing that CT had a good reliability and reproducibility in estimating LHO. Study IV: This is a prospective radiological study of 69 patients (70 shoulders) with primary osteoarthritis (OA) who had undergone stemless total anatomical shoulder arthroplasty (TSA). This study showed that stemless anatomical TSA could be useful in restoring shoulder anatomy. Study V: This is a prospective study of 44 patients with OA who had undergone stemless anatomical TSA with a clinical and radiological follow up ranging from 12 – 50 months. Our study showed that LHO reconstruction close to the anatomy of a healthy contralateral shoulder improved shoulder function. Stemless anatomical TSA help to restore LHO. Increasing LHO may have a negative effect on shoulder function at three months but had no effect at 12 months. The main conclusions of this thesis are: 1. TSA (anatomic and reverse) using stemless humeral components is reliable if bone quality is adequate. The complication rate is comparable with other shoulder prosthetic systems. 2. Glenoid overhang decreased complications in RSA. 3. LHO measurement on AP radiographs is less reliable and underestimates the distance when compared with CT. 4. Stemless TSA could be of help in reconstructing shoulder anatomy. 5. Shoulder reconstruction close to the anatomy of a healthy contralateral shoulder improves shoulder function. / Axelprotes kirurgi har visat avsevärd utveckling under de senaste decennierna. Ett antal faktorer påverkar postoperativt rörelseomfång, smärta och proteshållbarhet. Bland dessa faktorer utgör längden av hävarmen och ledstabilitet de faktorer som kan ändras genom val av proteskomponent. Det är osäkert om den normala anatomin måste återupprättas. Oskaftad protes med eliminering av humerusstamm och tillit till metafysär fixering introducerades i Frankrike år 2004 (TESS, Zimmer Biomet). Målen var att undvika stam relaterade komplikationer. Oskaftat implantat har andra potentiella fördelar, inklusive möjligheten att återställa axelnsanatomi. Syftet med denna avhandling var: (1) Att undersök radiologisk stabilitet av oskaftade axelproteser. (2) Att studera effekten av protes placering vid omvänd axelartroplastik både radiologiska och kliniskt utfall. (3) Att studera tillförlitlighet av mätningen av den laterala humeral offset (LHO), avståndet mellan processus coracoideus till laterala kanten av tuberkulum majus, med användning av CT eller röntgen. (4) Att studera oskaftad axelprotes förmåga att återställa axelnsanatomi. (5) Att studera den kliniska betydelsen av LHO återställning i för det funktionella resultatet efter axelartroplastik. Studie I: Detta är en prospektiv kohortstudie av 49 patienter med en av de två versionerna av TESS (anatomisk eller omvänd) med klinisk och radiologisk uppföljning från 9-24 månader. TESS protes visade lovande resultat på kort sikt med komplikationer som var jämförbar med andra axelprotessystem. Studie II: Detta är en prospektiv jämförande icke-randomiserad studie av 37 patienter (40 skuldror) som opererades med TESS omvänd axelartroplastik med en uppföljning från 15-66 månader. Vi fann en signifikant förbättring av funktion och minskning av smärta i både skaftad och oskaftad grupper. Glenoid overhang bedöms påverka risken för scapular notching (SN). Studie III: Detta är en radiologisk studie som visade att CT hade god tillförlitlighet och reproducerbarhet att mäta LHO. Studie IV: Detta är en prospektiv radiologisk studie av 69 patienter (70 skuldror) med primär artros som hade genomgått oskaftad total anatomisk axelprotes. Denna studie visade att oskaftad axelprotes kan vara till hjälp att återställa axelnsanatomi. Studie V: Detta är en prospektiv studie av 44 patienter med unilateral primär artros som hade genomgått oskaftad total axelprotes med en klinisk och radiologisk uppföljning från 12 - 50 månader. Vår studie visade att LHO rekonstruktion till den friska axeln förbättrar axelfunktion. Oskaftat implantat kan vara av hjälp till att återställa LHO. Ökad LHO kan ha en negativ effekt på axelnsfunktion vid tre månader, men denna effekt påvisade ej vid 12 månader. De viktigaste slutsatserna i denna avhandling är: 1. Oskaftad total axel artroplastik (anatomisk och omvänd) är tillförlitlig om benkvalitén är god med komplikationer som var jämförbar med andra axelprotessystem. 2. Glenoid overhang minskar komplikationer vid omvänd axelartroplastik. 3. LHO mätningen på röntgen är mindre tillförlitlig och underskattar avståndet jämfört med CT. 4. Oskaftad axelprotes skulle kunna vara till hjälp för att rekonstruera axelnsanatomi. 5. Axel rekonstruktion inom anatomi till att efterlikna anatomi på den friska kontralaterala axeln förbättrar axelfunktion.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg 1994. / This thesis presents an :investigation into the functional morphology and form of the skeletal elements of" the shoulder girdle of extant h0111inoids and extinct hO)ll.inids\~hich inhabited the Afr:i.c~n continent during the Late pliocene and Elarly \Ii Ii \Ii, ill Partic'l.l.lcu: emphasis is placed o\~\the \' i\. form of the scapula, clavicle and humerus. \Ii variation in the bony, arthrological and 41.yoloQif\;Lcal I" anatomy' Of this region in extant hominoids is I Pleistocene. examined. In light of biomechaniq~l models II reSUlting from this work, the bony,;anatomy of u hominid shoulder girdle elements examined and i. .1 r;:I~t>. ssil .1,1 . " biomechanical interpretations are made. The fossil shoulder girdle elements exan\ine~ in this study are grouped into four species samples. The first sample (Australopithecus a.:friCaIlUS) comprises Pliocene ,fossils from sterkfontein, South Africa. 'rhe second sampJ.e (A. afarelJ.si.s) i.s comprised of fossilo front Hadar, Ethiopia. The third (Homo habilis) and, fourth (ii. boisei) samples comprise fossils from C'lduvai GorgeI Ta:nzania, Koobi For~ll, Ke!nya and t.ne omo Valley ~ Ethiopia. When the t!;ossil homi.ndd. remains are scrt.ed into specf.ea, jl~heI:;houlder g;l.rdle elements InelYd:>e used to const.zuct; and contrast specd.es specijSiq '1· . ) bitOmechar1,ic::aml odelS of th~ shoulder. Th~~se models e:>fltP10re differernoes in form amon~,r.;tj;ossil hominid. species that may'be reJ,ated to dii.:;eetenc;:.es in behaviour. The models may also be appU.ed to the :~......,..~ interpretation of systemat.ic relationShips amongst early hominids. In o:(.~ierto construct models of early homi:p,ids it is first necessary to establish the,movement, myology and oste0logy of the extant hominoid shoulder. Chapters 4,5 and 6 sUl'l.1Il1ar~n,$eew data and available in,formation concel:"ning shoulder girdle mo.Jementand form. Chapter 7 presents detailed C';escriptiQns Of the fossil hominid ma.terial (u:::::19) available for study. 'rhis descriptive information, in conibination with all of the information derived from Chapters 4 through 6, is then used to inte1.pret, compaxe and contrast the fu.nctional morphology Of the shoulder girdle elements of each species of early hotninid. pa:q:ticuJ.ar emphasis is placed .on those features that cart be. directly related to specific :functiOl'l~ Model.s ,,.l the functional morphology of each of t1Je four species are then created. comparisons are made between indJ.vidual Shoulder girdle elements 'cg,fthe different homj.nid spacd.es as well as between the interpreted total morphology of each species' shoulder girdle. The study concludes that the functional m~>l':phologyof the shoulder girdle Qf A. afriaanus is unique ~unorJ.gstknown hominoic1~mode'l.s in that it poasesaes shoul<;ier girdle mo;t,'ph.oo.)gy adapted to bobh suspen ory behaviour and bipE~d;;d~i.srn. TIte suspensory adaptations are :Lndi9ated by the overall ape ..like morphology of the humeri, claviculae and heCid.of the scapulae, whilst bipedalism is mainly (J G indicated. by a broad, human-like inf.Ell:'ior'an9,'].eof " = the scapula. Several' RpparentlY prim.itive featu:r:es" are present in,..the A. africanus Ejcapl,1la,incl~dirtg a 0i,? ..... . _ .. '. \ shortened scapular 'n~ck, that ind:l.Cate'-\poss~ple ancestry f.roma quadru:pedal form. ~p.e functi<:>tJ.al. morphology of the A. afarens.ts shoulder is founa .to be more diffi.cult to interpret d'.le to poor f(i:; ,pre.~ervationt but the hypothesised znodel'~does not diffe):: substantially from th~t constructed for A. _c,~) . ..' .', 1) (; a£ricanus. The few robust aURtra.lopithecine,.,(A. boi.se:1) sho~~der girdle elements appear to possess ~,.. similar morpJ;lologi.esto A. a.:falyrnsis and )1- africanus. There ara .no'l:.SUfi:'lc:tently well preServedoH. habili.s shoulder girdle elements preserved to 'makemeffilningfulinterpreta.tions about the functional morphology of this, specie~:' .' n the lack of comparable elements amongst the two (I 1arger samples (...21.. a:faJ;'ensi.s and ,fl. arr:J;canus) I .it '..':::/ is not knownwhether the features found to be apparently unique to either species are useful as n taxonomic indicators.