Bearing-spesific complications of total hip arthroplasty: characterization and treatment

Hip resurfacing arthroplasty (HRA) and large head metal-on-metal total arthroplasty (LDH MoM THA) gained popularity during the last decade. Adverse reaction to metal debris (ARMD) is a unique complication of metal bearings. ARMD is a complex reaction caused by metal debris from metal-on- metal bearing surfaces and from trunnion corrosion of modular junctions. We analyzed survivorship of 8059 LDH MoM THAs based on data of the Finnish Arthroplasty Register. We found relatively high short-term survivorship for some LDH MoM THAs, but there were remarkable differences between the devices studied. After some alarming reports of failing MoM THAs, we studied the first 80 patients who had received a ReCap-M2a-Magnum implant at our institution and evaluated the prevalence of ARMD. We found a high prevalence of pseudotumors, and, because of this, we discontinued the use of MoM bearings and followed up all patients with a MoM THA. Bone loss due infection, osteolysis or fracture poses a great challenge for reconstructive and fracture surgery. Onlay allografting for both revision and fracture surgery provides mechanical stability and increases bone stock. Bone loss and implant stability must be assessed preoperatively and adequately classified; this provides guidelines for the operative treatment of periprosthetic fractures and revision THA. In our studies on structural allografts union rates were high, although the rates of infections and dislocations were marked. In summary, early results of the use of LDH MoM devices were encouraging. However, the survival of the LDH MoMs varied. The prevalence of adverse reaction to metal debris was high after application of the ReCap-Magnum THA. New implants should be introduced carefully and under close surveillance by University clinics and arthroplasty registers.Lonkan tekonivelen liukupinnalle tyypilliset komplikaatiot ja niiden hoito Lonkan pinnoitetekonivelen (HRA) ja isonuppisen metalli-metalli liukupintaisen tekonivelen (LDH MoM THA) käyttö yleistyi nopeasti viime vuosikymmenen aikana. Metalli--metalli liukupintoihin ja kartioliitoksiin liittyvä metallihierrekomplikaatio (adverse reaction to metal debris, ARMD) liityy lähes yksinomaan metalli-metalli liukupintoihin. Lisääntynyt tekonivelien modulaarisuus lisää metallihierrekomplikaatioiden riskiä . Tutkimuksessani analysoin 8059 LDH MoM -tekonivelen pysyvyyttä lyhyellä ja keskipitkällä aikavälillä Implanttirekisterin tietoihin perustuen. Pysyvyystulokset olivat hyviä, mutta ne vaihtelivat merkittävästi eri mallien välillä jo lyhyelläkin aikavälillä. Metalli-metalli liukupintaan liittyvien ongelmien raportoinnin yleistyessä teimme retrospektiivisen, 80 ensimmäistä implantoitua ReCap- M2a-Magnum–tekoniveltä koskevan tutkimuksen. Metallihierrekomplikaatio oli yleinen löydös, jonka seurauksena metalli-metalli liukupintaisten tekonivelten käyttö lopetettiin klinikassamme. Luukato tekonivelen ympärillä johtuu useimmiten infektiosta, osteolyysistä tai murtumasta. Periproteettisten murtumien hoito on vaativaa. Myös luunpuutos lonkan tekonivelen uusintaleikkauksissa aiheuttaa hoidollisia haasteita. Rakenteellisten luunsiirteiden paranemista koskevat tutkimustuloksemme olivat hyvät, mutta myös infektioiden ja sijoiltaanmenojen määrä oli varsin suuri. Kaiken kaikkiaan varhaiset LDH MoM tekonivelten käyttökokemukset olivat olleet rohkaisevia, mutta kaikki mallit eivät olleet pysyvyydeltään yhdenveroisia. Metalli- metalli liukupintaan ja kartioliitokseen liittyvä metallihierrekomplikaatio (ARMD) oli yleinen ReCap-Magnum-implanttia käytettäessä. Uudet implantit tulee maassamme ottaa käyttöön yliopistosairaaloiden tekonivelyksiköiden valvonnan alla. Tekonivelrekisteri on avainasemassa uusien tuotteiden arvioinnissa jo ennen kuin uusi tekonivelmalli vapautetaan laajaan käyttöön.Siirretty Doriast

Radiographic geometry and clinical glenohumeral range of motion after reverse shoulder athroplasty, a retrospective cohort study

BackgroundThe range of motion (ROM) in reverse shoulder arthroplasty (RSA), is mechanically limited by the surrounding bony obstacles especially in abduction and rotation planes. However, the clinical effect of implant positioning, prosthesis design, and individual differences in bone morphology, on ROM is obscure. The aim of this study was to investigate the correlation between radiographic geometry and clinical glenohumeral (GH) ROM after RSA.MethodsRSA patients operated at Turku University Hospital during 2007–2013 were called for radiological and clinical follow-up. Pre- and postoperative true anteroposterior radiographs were obtained and the positioning of the center of rotation (COR) in relation to the surrounding bony structures was measured. Active and passive shoulder and GH abduction, flexion, internal and external rotation ROM were measured with goniometer. The Constant score (CS) and pain visual analogue scale (VAS) were recorded. The correlation between the radiographically measured parameters and the active and passive ROM and clinical outcome was statistically analyzed.Results91 shoulders were available for analyses with a mean follow-up of 38.7 months ± SD 20 (range 12–83) months. 77% of the patients were female, the mean age was 73 (SD 9) years. The mean angle between the line of supraspinatus fossa, and the line between COR and lateral edge of the acromion (α-angle) was 127° (SD 14) and the mean angle between the lines from lateral edge of the acromion to COR, and from there to the superior edge of the greater tubercle (β-angle) was 54° (SD 11). The mean active shoulder flexion at follow-up was 118° (SD 26), abduction 104° (SD 32), external rotation 41° (SD 22), internal rotation 77° (SD 21). The mean passive GH flexion was 80° (SD 19), abduction 67° (SD 15), external rotation 31° (SD 16) and internal rotation 34° (SD 14). The mean Constant score at follow-up was 53 (SD 18) and pain VAS 2 (SD 3). The positioning of the radiographically measured COR did not statistically significantly correlate with the ROM or clinical outcome scores.ConclusionsPostoperative radiographically measured two-dimensional geometry and positioning of the COR does not significantly correlate with the glenohumeral range of motion or clinical results after RSA.</p

Radiographic geometry and clinical glenohumeral range of motion after reverse shoulder athroplasty, a retrospective cohort study

Background: The range of motion (ROM) in reverse shoulder arthroplasty (RSA), is mechanically limited by the surrounding bony obstacles especially in abduction and rotation planes. However, the clinical effect of implant positioning, prosthesis design, and individual differences in bone morphology, on ROM is obscure. The aim of this study was to investigate the correlation between radiographic geometry and clinical glenohumeral (GH) ROM after RSA. Methods: RSA patients operated at Turku University Hospital during 2007–2013 were called for radiological and clinical follow-up. Pre- and postoperative true anteroposterior radiographs were obtained and the positioning of the center of rotation (COR) in relation to the surrounding bony structures was measured. Active and passive shoulder and GH abduction, flexion, internal and external rotation ROM were measured with goniometer. The Constant score (CS) and pain visual analogue scale (VAS) were recorded. The correlation between the radiographically measured parameters and the active and passive ROM and clinical outcome was statistically analyzed. Results: 91 shoulders were available for analyses with a mean follow-up of 38.7 months ± SD 20 (range 12–83) months. 77% of the patients were female, the mean age was 73 (SD 9) years. The mean angle between the line of supraspinatus fossa, and the line between COR and lateral edge of the acromion (α-angle) was 127° (SD 14) and the mean angle between the lines from lateral edge of the acromion to COR, and from there to the superior edge of the greater tubercle (β-angle) was 54° (SD 11). The mean active shoulder flexion at follow-up was 118° (SD 26), abduction 104° (SD 32), external rotation 41° (SD 22), internal rotation 77° (SD 21). The mean passive GH flexion was 80° (SD 19), abduction 67° (SD 15), external rotation 31° (SD 16) and internal rotation 34° (SD 14). The mean Constant score at follow-up was 53 (SD 18) and pain VAS 2 (SD 3). The positioning of the radiographically measured COR did not statistically significantly correlate with the ROM or clinical outcome scores. Conclusions: Postoperative radiographically measured two-dimensional geometry and positioning of the COR does not significantly correlate with the glenohumeral range of motion or clinical results after RSA. Level of evidence: Level 3, retrospective cohort studypublishedVersionPeer reviewe