A case-driven hypothesis for multi-stage crack growth mechanism in fourth-generation ceramic head fracture

Abstract

Background Ceramic bearings are used in total hip arthroplasty due to their excellent wear behaviour and biocompatibility. The major concern related to their use is material brittleness, which significantly impacts on the risk of fracture of ceramic components. Fracture toughness improvement has contributed to the decrease in fracture rate, at least of the prosthetic head. However, the root cause behind these rare events is not fully understood. This study evaluated head fracture occurrence in a sizeable cohort of patients with fourth-generation ceramic-on-ceramic implants and described the circumstances reported by patients in the rare cases of head fracture. Methods The clinical survivorship of 29,495 hip prostheses, with fourth-generation ceramic bearings, was determined using data from a joint replacement registry. The average follow-up period was 5.2 years (range 0.1–15.6). Retrieval analysis was performed in one case for which the ceramic components were available. Results Clinical outcomes confirmed the extremely low fracture rate of fourth-generation ceramic heads: only two out of 29,495 heads fractured. The two fractures, both involving 36 mm heads, occurred without a concurrent or previous remarkable trauma. Considering the feature of the fractured head, a multi-stage crack growth mechanism has been hypothesized to occur following damage at the head–neck taper interface. Conclusions Surgeons must continue to pay attention to the assembly of the femoral head: achieving a proper head seating on a clean taper is a prerequisite to decrease the risk of occurrence of any damage process within head–neck junction, which may cause high stress concentration at the contact surface, promoting crack nucleation and propagation even in toughened ceramics.

Global mapping of institutional and hospital-based (Level II–IV) arthroplasty registries: a scoping review

“…Postoperative complications, short and long-term clinical outcomes, PROMs and QALYs, the efficacy of specific implants, comparison of different surgical techniques and survival analyses were among the main outcome of the published studies. The “Register of Orthopaedic Prosthetic Implant (RIPO) of Emilia-Romagna region” published 30 papers from 2002 to 2022 [ 24 , 645 ]. Among them, twenty-eight were cohort studies [ 24 , 26 , 39 , 43 , 57 , 145 , 164 , 189 , 231 , 288 , 297 , 482 , 491 , 502 , 506 , 508 , 527 , 540 , 562 , 563 , 569 , 585 , 592 , 597 , 599 , 624 , 630 , 645 ], one was RCT [ 476 ] and one registry protocol [ 468 ].…”

“…The “Register of Orthopaedic Prosthetic Implant (RIPO) of Emilia-Romagna region” published 30 papers from 2002 to 2022 [ 24 , 645 ]. Among them, twenty-eight were cohort studies [ 24 , 26 , 39 , 43 , 57 , 145 , 164 , 189 , 231 , 288 , 297 , 482 , 491 , 502 , 506 , 508 , 527 , 540 , 562 , 563 , 569 , 585 , 592 , 597 , 599 , 624 , 630 , 645 ], one was RCT [ 476 ] and one registry protocol [ 468 ]. Of these 30 studies, 16 were survival [ 26 , 164 , 189 , 231 , 288 , 482 , 491 , 502 , 508 , 527 , 540 , 563 , 569 , 585 , 592 , 599 ], six analysed implant types [ 24 , 43 , 297 , 506 , 624 , 645 ], and two studied postoperative complications [ 597 , 630 ].…”

“…Among them, twenty-eight were cohort studies [ 24 , 26 , 39 , 43 , 57 , 145 , 164 , 189 , 231 , 288 , 297 , 482 , 491 , 502 , 506 , 508 , 527 , 540 , 562 , 563 , 569 , 585 , 592 , 597 , 599 , 624 , 630 , 645 ], one was RCT [ 476 ] and one registry protocol [ 468 ]. Of these 30 studies, 16 were survival [ 26 , 164 , 189 , 231 , 288 , 482 , 491 , 502 , 508 , 527 , 540 , 563 , 569 , 585 , 592 , 599 ], six analysed implant types [ 24 , 43 , 297 , 506 , 624 , 645 ], and two studied postoperative complications [ 597 , 630 ]. Long-term postoperative outcomes [ 562 ], cost [ 57 ] and risk factors analysis [ 39 ], genetic studies [ 476 ], a protocol for registry study [ 468 ] and comparison of different surgical techniques [ 145 ] were among the primary outcomes of other study types.…”

Ceramic fragmentation after total hip arthroplasty: two case reports and literature review

“…Improper impaction of the femoral head prosthesis during surgery has also been identified as a potential risk factor for ceramic head fracture ( 43 ). Although the use of fourth-generation ceramics significantly improves the material's resilience, making it less prone to brittle fracture, orthopedic surgeons still need to pay attention to obtaining proper head seating on a clean taper during femoral head assembly as a prerequisite to reduce the risk of any damage occurring at the head-taper junction ( 44 ). The surgeon's clinical experience and expertise play a crucial role in ensuring the success of the surgery and the safety of the patient.…”

“…Our second patient had experienced sudden-onset pain without an obvious trigger or trauma. Lucchini et al ( 44 ) demonstrated that ceramic head fracture can occur even without complications or significant previous trauma. Slight micromotion can lead to interface damage, leading to the loosening of the ceramic head and ultimately resulting in ceramic femoral head fracture.…”