ABSTRACT
PURPOSE: Autologous matrix-induced chondrogenesis (AMIC) showed promising short-term results comparable to microfracture. This study aims to assess the 19-year outcomes of AMIC, addressing the lack of long-term data. METHODS: Retrospective cohort of 34 knees treated with AMIC underwent a 19-year follow-up. The primary outcome was AMIC survival, considering total knee arthroplasty as a failure event. Survival analysis for factors that were associated with longer survival of the AMIC was also performed. Clinical and radiological outcome scores were analysed for the AMIC group. RESULTS: Twenty-three knees were available for follow-up analysis. Of these, 14 (61%) underwent revision surgery for total knee arthroplasty (TKA). The mean time was 13.3 ± 2.5 years (range: 9-17 years). Secondary outcomes showed that increased age at surgery (hazard ratio [HR]: 1.05; p = 0.021) and larger defect size (HR: 1.95; p = 0.018) were risk factors for failure. Concomitant proximal tibial osteotomy (HR: 0.22; p = 0.019) was associated with longer survival. The remaining nine knees (39%) were analysed as a single group. The mean clinical score at follow-up of 18.6 ± 0.9 SD years was 79.5 ± 19.7 SD for the Lysholm score, 1.8 ± 1.5 SD for the visual analog scale score, 74.2 ± 22.4 SD for the KOOS score and a median of 3 (range: 3-4) for the Tegner activity scale. CONCLUSIONS: The mean survival time of 13.3 years indicates the durability of AMIC in properly aligned knees. Nonetheless, despite a 61% conversion to TKA, the knees that persisted until the 19-year follow-up remained stable, underscoring the procedure's longevity and consistent clinical outcomes. LEVEL OF EVIDENCE: Level IV.
ABSTRACT
Background: Acetabular protrusion is an acetabular defect caused by the shift of the femoral head through the pelvic bone. Because of bone loss, usual anatomical landmarks may be confusing or absent, leading to a particularly high demanding surgical reconstruction in case of total hip arthroplasty (THA) implantation, without adequate support of the acetabulum due to major acetabular defect. To our knowledge, no article has dealt with acetabular defects to this extent and associated femoral osteolysis, which we will attempt to do in this case report. That's why we would like to share this case in order to propose an interesting alternative for the management of these challenging pathologies. Case Description: We hereby present the case of a rare pattern of severe acetabular prosthetic protrusion through the pelvic ring on a 77-year-old patient without any trauma. He was surgically treated with acetabular metal augment and a wide femoral modular reconstruction prosthesis. An instability was revealed after 6 weeks, so he underwent an early surgical revision with a constraint cup, overwhelming the absence of abductor apparatus. After this, his recovery was complete and uneventful, with effective function of the reconstructed hip joint and adequate stability of the prosthesis. Conclusions: Although acetabular protrusion is a rare complication in total hip replacement patients, we would like to draw attention to the challenging nature of this complication, both in terms of initial assessment and surgical management. The described strategy showed effective function of the reconstructed hip joint and final adequate stability of the prosthesis despite the absence of a competent abductor apparatus.