Radiološka analiza nestabilnih femoralnih komponenti Zweymuller tipa tvrtke Instrumentaria d.d.

master's thesis

• Title (english): Radiologic analysis of unstable components of Zweymuller-type hip endoprothesis by the Instrumentaria manufacturer
• Author: Dario Smirnjak
• Mentor: Tomislav Smoljanović (mentor)
• Committee member: Domagoj Delimar (predsjednik povjerenstva)
• Committee member: Tomislav Đapić (član povjerenstva)
• Committee member: Tomislav Smoljanović (član povjerenstva)
• Granter: University of Zagreb; School of Medicine; (Department of Orthopedics); Zagreb
• Defense date and country: 2024-09-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Clinical Medical Sciences; Orthopedics

Abstract

U Klinici za ortopediju Kliničkog bolničkog centra Zagreb ugrađeno je tijekom četverogodišnjeg razdoblja od kolovoza 2014. godine do srpnja 2018. godine u 979 pacijenata ukupno 1051 Zweymuller-tip femoralne komponente bescementne endoproteze kuka tvrtke Instrumentaria d.d. Analiza preživljenja tih endoproteza učinjena 2023. godine pokazala je kako je u 8,4 % pacijenata dostupnih praćenju femoralni stem bio operacijski revidiran. Cilj ovog rada je analizirati radiološke promjene revidiranih femoralnih stemova do početka 2024. godine. U analizi su korištene rendgenske snimke kukova snimljene prije i neposredno nakon operacijskog zahvata ugradnje endoproteze kuka te kasnije tijekom praćenja. Od 74 revidirana femoralna stema radiološka dokumentacija potrebna za analizu bila je dostupna za 56 pacijenata (75,7 %). Femoralni stem nije bio primarno postavljen u idealni položaj u četiri pacijenta (7,1 %). Tijekom praćenja gubitak gustoće proksimalne kortikalne kosti (engl. stress shielding) uočen je u 49 pacijenata (87,5 %). Kortikalna hipertrofija na distalnom dijelu femoralnog stema uočena je u 21 pacijenta (37,5 %). Radiolucentne linije na kontaktnoj površini između kortikalne kosti i femoralnog stema bile su prisutne u 50 pacijenata (89,3 %). Radiolucencije širine veće od 2 milimetra opisane su u 27 (48,2 %) pacijenata. Utonuće stema u femoralni kanal nađeno je u 44 pacijenta (78,6 %). Prosječno utonuće iznosilo je 6,7 milimetara (raspon 1-21 milimetar). Utonuće stema više od 5 milimetara zabilježeno je u 25 pacijenata (44,6 %). Pomak femoralnog stema s obzirom na uzdužnu os femura uočen je u 24 pacijenta (42,9 %). Ukupno 12 revidiranih pacijenata nije imalo radioloških znakova razlabavljenja femoralne komponente. Radiološki znakovi nestabilnosti femoralnog stema tvrtke Instrumentaria d.d. bili su prisutni u 78,6 % pacijenata. Najučestaliji radiološki znakovi nestabilnosti femoralnog stema su utonuće stema i pojava progresivne radiolucentne linije.

Abstract (english)

A total of 1,051 Zweymuller-type femoral components of cementless hip endoprostheses from the Instrumentaria manufacturer were implanted in 979 patients in the Orthopedic Clinic of the Zagreb Clinical Hospital Center during the four-year period from August 2014 to July 2018. The survival analysis of these endoprostheses performed in 2023 showed that the femoral stem was surgically revised in 8.4% of patients available for follow-up. This study aims to analyze the radiological changes of the revised femoral stems until the beginning of 2024. X-rays of the hips taken before and immediately after surgery as well as later during follow-up were used in the analysis. Of the 74 revised femoral stems, radiological documentation required for the analysis was available for 56 patients (75.7 %). The femoral stem was not primarily placed in the ideal position in four patients (7.1 %). During follow-up, loss of proximal cortical bone density (stress shielding) was observed in 49 patients (87.5 %). Cortical hypertrophy on the distal part of the femoral stem was observed in 21 patients (37.5 %). Radiolucent lines on the contact surface between the cortical bone and the femoral stem were present in 50 patients (89.3 %). Lucencies wider than 2 millimeters were found in 27 (48.2 %) patients. Subsidence of the stem into the femoral canal was found in 44 patients (78.6 %). The average subsidence was 6.7 millimeters (range 1-21 millimeters). Subsidence of more than 5 millimeters was recorded in 25 patients (44.6 %). Stem migration regarding the longitudinal axis of the femur was observed in 24 patients (42.9 %). A total of 12 revised patients had no radiological signs of femoral component loosening. Radiological signs of instability of the femoral stem of Instrumentaria manufacturer were present in 78.6 % of patients. The most common radiological signs of femoral stem instability are the subsidence of the stem and the appearance of a progressive radiolucent line.

• Keywords: artroplastika; endoproteza; razlabavljenje; stem
• Keywords (english): arthroplasty; implant; loosening; stem
• Language: croatian
• URN:NBN: urn:nbn:hr:105:112363
• Study programme: Title: Medicine; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: doktor/doktorica medicine (doktor/doktorica medicine)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-09-04 11:03:02