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BackgroundAcute TKA has been proposed as an alternative to open reduction and internal fixation for complex tibial plateau fractures in patients who are older and who have compromised bone quality. The alternative is a delayed TKA after primary fracture management with an unfavorable outcome. However, the long-term outcomes and risk for reoperation after acute TKA compared with delayed TKA for fracture sequelae remain unclear.Questions/purposesWhen comparing acute TKA (< 3 months after injury) for tibial plateau fracture with delayed TKA for fracture sequelae, we asked: (1) Do the risks of reoperation or revision for any cause differ? (2) Do the risks of reoperation or revision for infection differ? (3) Do the risks of reoperation or revision for loosening differ?MethodsData for all TKAs performed between 2014 and 2023 with the indication of acute tibial plateau fracture (n = 152) or fracture sequelae (n = 950) were extracted from the Swedish Arthroplasty Register. Patients who underwent TKA for acute tibial plateau fractures were older (73 versus 66 years), more often women (78% [118 of 152] versus 57% [539 of 950]), had lower BMI (26.7 versus 27.9 kg/m2), and received constrained or hinged implants more frequently (59% [89 of 152] versus 33% [311 of 950]). Reoperations were identified in the Swedish Arthroplasty Register through subsequent procedures on the index knee and classified as reoperations (where the implant remained in situ) or revisions (with exchange, addition, or removal of components). When bilateral procedures occurred within the study period, only the first TKA was retained to ensure independence of observations. Loss to follow-up because of emigration or incomplete revision reporting was expected to be minimal, as the Swedish Arthroplasty Register captures approximately 98% of primary TKAs and 94% of revisions nationally. We estimated the cumulative event probability of secondary procedures using the Kaplan-Meier method and used logistic regression models to estimate adjusted ORs for (1) any reoperation or revision, (2) infection-related procedures, and (3) loosening-related procedures, adjusting for age, gender, and BMI. Because implant type reflects the underlying clinical situation and cannot be reliably adjusted for, it was reported descriptively.ResultsDuring follow-up, 7% (78 of 1102) of patients underwent a reoperation and 5% (60 of 1102) of patients underwent a revision. At 5 years, the cumulative event probability of any revision was 8% (95% confidence interval [CI] 2% to 14%) for acute TKA and 5% (95% CI 4% to 7%) for delayed TKA (p = 0.41). For reoperations, the cumulative event probability at 5 years was 9% (95% CI 3% to 15%) for acute TKA and 7% (95% CI 5% to 9%) in the delayed TKA group (p = 0.26). After adjusting for age, gender, and BMI, there was no difference between groups in odds for any reoperation (OR 0.76 [95% CI 0.38 to 1.5]; p = 0.43) or any revision (OR 0.68 [95% CI 0.31 to 1.5]; p = 0.32). Infections accounted for 9% (1 of 11) of reoperations for acute TKAs and 40% (27 of 67) of delayed TKAs. At 5 years, the cumulative event probability of reoperation or revision due to infection was 2% (95% CI 0% to 5%) for acute TKA and 3% (95% CI 2% to 4%) for delayed TKA (p = 0.06). There was no difference in the adjusted odds of infection-related reoperation (OR 3.7 [95% CI 0.48 to 28]; p = 0.21) or infection-related revision (OR 3.0 [95% CI 0.40 to 23]; p = 0.28). Loosening accounted for 27% (3 of 11) of revisions after acute TKAs and 9% (6 of 67) after delayed TKAs. At 5 years, the cumulative event probability of loosening-related revision was 2.9% (95% CI 0% to 7.1%) for acute TKAs and 0.6% (95% CI 0.1% to 1.2%) for delayed TKAs (p = 0.50). The adjusted odds of loosening-related revision were lower for delayed TKAs (OR 0.21 [95% CI 0.05 to 0.97]; p = 0.045).ConclusionThe timing and pattern of revision differ between the two investigated groups, with delayed TKAs undergoing unplanned reoperation or revision earlier and with a higher proportion of infection-related revisions, whereas acute TKAs underwent reoperation or revision later and with a higher proportion of revisions for mechanical loosening. In the absence of large prospective trials, future observational work should include evaluation of pre- and postoperative radiographs and patient-reported outcomes, to determine which patients may benefit from acute TKA for tibial plateau fracture.

Proximal tibia fractures (PTF) account for similar to 1% of all adult fractures and show a bimodal age distribution, occurring after high-energy trauma in younger individuals and low-energy fragility fractures in the elderly. Contemporary nationwide data on incidence and management are lacking for Sweden. The aim of the present study was therefore to investigate the incidence and management of PTFs in Sweden using nationwide register data. Specifically, we sought to (1) determine the incidence of PTFs over time, (2) describe demographic characteristics of affected patients, and (3) analyse treatment patterns, including the use of acute arthroplasty. Using the Swedish National Patient Register, all patients >= 18 years of age, with a diagnosis of PTF (ICD-10 S82.1) between 2011 and 2023 were included. Incidence rates were calculated using national population data and reported per 100,000 person-years. Patient demographics and treatment patterns, including surgical methods, were analysed and compared between sex and age groups. A total of 38,053 patients with PTF were identified (60% women, mean age 57 years). The overall incidence increased from 36.7 per 100,000 person-years in 2011 to 40.1 in 2023 (+ 9.3%). Incidence remained stable in men (31.0 to 30.3), while it increased by 18.5% in women (42.2 to 50.0). The highest incidence-rate throughout the study period was observed among women aged >= 80 years, although rates in this group declined from 111.0 per 100,000 person-years 2011 to 90.3 in 2023 (-18%). The largest relative increase occurred in women aged 20-29 years (12.7 to 25.4; +100%). Between 2011 and 2023, 29% of patients underwent surgery, most commonly plate fixation (71.6%). The incidence of PTFs in Sweden has increased modestly over the past decade, driven primarily by a rise among young women. Up to the age of 50, the majority of PTFs were sustained by men (n = 7849, 57.6%), whereas above 50 the vast majority were sustained by women (n = 17249, 70.6%). Surgical treatment rate has been stable over the 13 years study period, with the large majority being treated with plate fixation.

Tibial plateau fractures (TPFs) encompass a broad spectrum of injuries, ranging from simple, undisplaced splits to complex intra-articular fracture patterns. These fractures are frequently associated with long-term sequelae, most notably post-traumatic osteoarthritis (PTOA) and eventual conversion to total knee arthroplasty (TKA). As the incidence of fragility fractures is projected to rise within expanding ageing populations, the burden of TPF-related knee degeneration is expected to increase substantially. Despite advances in internal fixation techniques, uncertainty persists regarding long-term clinical outcomes, the risk factors driving joint deterioration, and the potential role of primary arthroplasty for selected patients.

The overarching aim of this thesis was to investigate the long-term consequences of TPF, with focus on epidemiology, the progression to TKA, and the role of patient- and fracture-related characteristics in risk stratification for joint conversion. This objective was addressed through a series of longitudinal cohort studies, leveraging both single-centre clinical data and comprehensive national register-based datasets. First, national incidence patterns and mortality rates following TPF were evaluated using the National Patient Register (NPR). A single-centre cohort study linked to the Swedish Arthroplasty Register (SAR) was used to identify factors associated with subsequent TKA conversion. Subsequently, national data from the SFR were linked to the SAR to examine the association between fracture severity and TKA conversion within a large, population-based cohort. Finally, SAR data were analysed to evaluate clinical outcomes following acute TKA as a primary treatment for TPF, with these results compared against outcomes of delayed TKA performed for PTOA.

Findings from this thesis indicate that although most TPFs managed with ORIF have low TKA conversion rates, a distinct subset of patients faces an elevated risk of conversion. This high-risk group is characterised by severe fracture patterns, advanced age, and inadequate postoperative reduction. Moreover, TKA following TPF often resembles revision surgery rather than primary arthroplasty in terms of surgical complexity, implant selection, and clinical outcomes. Consequently, acute arthroplasty in carefully selected high-risk individuals may serve as a viable primary intervention with favourable results.

In conclusion, this thesis offers new insights into the trajectory from fracture to arthroplasty following TPF. The findings underscore the critical importance of achieving high-quality anatomical reduction, early stratification of patients at elevated risk of failure, and individualised decision-making regarding joint preservation versus primary arthroplasty. Collectively, these findings advance clinical understanding and provide a foundation for future research aimed at refining treatment strategies and improving long-term outcomes.

Background: Tibial plateau fractures (TPFs) can be associated with development of significant joint degeneration, which can lead to functional impairment and pain severe enough to necessitate conversion to total knee arthroplasty (TKA). The factors influencing the progression to TKA after TPF, including preoperative fracture and patient characteristics, remain unclear. This study aimed to assess the national conversion rate to TKA following TPF depending on fracture type.

Patients and methods: The cohort consisted of all patients aged 18 years and older at time of injury with a TPF registered in the Swedish Fracture Register (SFR) between 2012 and 2023. The SFR holds information on baseline patient characteristics including fracture classification according to the AO/OTA system. Conversion to TKA was identified through linkage with the Swedish Arthroplasty Register (SAR). Kaplan-Meier survival analyses investigated conversion rate. Cox regression was performed to assess association between fracture type and TKA conversion adjusted for age, sex, and injury energy level. The follow-up period ranged from 0 to 12 years, with a mean of 4.2 years.

Results: A total of 12,012 patients with a mean age of 57 years were included; 63% were women. The observed conversion rate after 5 years was 2.8% in all patients and 4.1% in surgically treated patients. The conversion rate at 5 years was highest in the 65-74 years age group with 5.2%. Fractures with comminuted fracture patterns, particularly AO/OTA 41B3, 41C2, and 41C3, were associated with significantly increased risks of conversion, with adjusted hazard ratios (aHRs) of 2.1 (95% CI 1.3-3.3), 2.3 (1.2-4.5), and 3.2 (95% CI 2.0-4.5), respectively. High-energy trauma did not increase the risk of conversion, nor did sex. Increasing age was associated with an increased risk of conversion up to the age of 84, while age over 85 was not.

Conclusions: Fractures with complex fracture patterns, particularly AO/OTA 41B3, 41C2, and 41C3, were associated with an increased TKA conversion rate following TPF. The conversion rate increased with increasing age, but sex and high-energy injury mechanisms did not affect conversion rate. On a national level, 3% of patients were converted to TKA within 5 years of sustaining a TPF, and 4% of patients treated surgically. This may help surgeons when counseling patients with TPFs.

Background and purpose: We aimed to assess joint failure rate, i.e., subsequent conversion to TKA after surgical treatment of a tibial plateau fracture (TPF). Secondary aims were to explore the association between joint failure and fracture type, and to determine the risk of failure associated with inadequate joint surface reduction.

Methods: We included all patients ≥ 18 years of age with a surgically treated TPF, treated at Uppsala University Hospital between 2002 and 2015. All fractures were classified according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Traumatology Association (AO/OTA) classification. Postoperative radiographs were evaluated to determine the quality of joint surface inadequate reduction, defined as an articular step-off ≥ 2 mm. The study cohort was linked with the Swedish Arthroplasty Register (SAR) for information on subsequent total knee arthroplasty (TKA).

Results: 439 patients (57% women) with a mean age of 55 years (SD 17) were included. According to the AO/OTA classification, the fracture distribution was B1: 4.8%, B2: 10%, B3: 47%, C1: 12%, C2: 6.4%, and C3: 19%. 23 patients (5.2%) were converted to a TKA within 2 years of initial surgery, and 34 patients (7.7%) had been converted by the end of follow-up (16 years). AO/OTA type B3 and C3 had a 6.8 (95% confidence interval [CI] 1.6–29) times greater risk of joint failure compared with B1–2 and C1–C2 at 2 years’ follow-up. Inadequate joint surface reduction led to an 8.4 (CI 3.6–20) times greater risk of conversion to TKA at 2 years’ follow-up.

Conclusion: Overall, 5.2% were converted to a TKA within 2 years. Fracture types AO/OTA B3 and C3 with a comminuted articular surface and inadequate joint surface reduction were strongly associated with joint failure.