Aims. Endoprosthetic reconstruction with a distal femoral arthroplasty (DFA) can be used to treat distal femoral bone loss from oncological and non-oncological causes. This study reports the short-term implant survivorship, complications, and risk factors for patients who underwent DFA for non-neoplastic indications. Methods. We performed a retrospective review of 75 patients from a single institution who underwent DFA for non-neoplastic indications, including aseptic loosening or mechanical failure of a previous prosthesis (n = 25), periprosthetic joint infection (PJI) (n = 23), and native or periprosthetic distal femur fracture or nonunion (n = 27). Patients with less than 24 months’ follow-up were excluded. We collected patient demographic data, complications, and reoperations. Reoperation for implant failure was used to calculate implant survivorship. Results. Overall one- and five-year implant survivorship was 87% and 76%, respectively. By indication for DFA, mechanical failure had one- and five-year implant survivorship of 92% and 68%, PJI of 91% and 72%, and distal femur fracture/nonunion of 78% and 70% (p = 0.618). A total of 37 patients (49%) experienced complications and 27 patients (36%) required one or more reoperation. PJI (n = 16, 21%), aseptic loosening (n = 9, 12%), and wound complications (n = 8, 11%) were the most common complications. Component revision (n = 10, 13.3%) and single-stage exchange for PJI (n = 9, 12.0 %) were the most common reoperations. Only younger age was significantly associated with increased complications (mean 67 years (SD 9.1)) with complication vs 71 years (SD 9.9) without complication; p = 0.048). Conclusion. DFA is a viable option for distal femoral bone loss from a range of non-oncological causes, demonstrating acceptable short-term survivorship but with high overall complication rates. Cite this article: Bone Jt Open 2022;3(3):173–181

Aims. The purpose of this study was to assess mid-term survivorship following primary total knee arthroplasty (TKA) with Optetrak Logic components and identify the most common revision indications at a single institution. Methods. We identified a retrospective cohort of 7,941 Optetrak primary TKAs performed from January 2010 to December 2018. We reviewed the intraoperative findings of 369 TKAs that required revision TKA from January 2010 to December 2021 and the details of the revision implants used. Kaplan-Meier analysis was used to determine survivorship. Cox regression analysis was used to examine the impact of patient variables and year of implantation on survival time. Results. The estimated survivorship free of all-cause revision was 98% (95% confidence interval (CI) 97% to 98%), 95% (95% CI 95% to 96%), and 86% (95% CI 83% to 88%) at two, five, and ten years, respectively. In 209/369 revisions there was a consistent constellation of findings with varying severity that included polyethylene wear and associated synovitis, osteolysis, and component loosening. This failure mode, which we refer to as aseptic mechanical failure, was the most common revision indication. The mean time from primary TKA to revision for aseptic mechanical failure was five years (5 months to 11 years). Conclusion. In this series of nearly 8,000 primary TKAs performed with a specific implant, we identified a lower-than-expected mid-term survivorship and a high number of revisions with a unique presentation. This study, along with the recent recall of the implant, confirms the need for frequent monitoring of patients with Optetrak TKAs given the incidence of polyethylene failure, osteolysis, and component loosening. Cite this article: Bone Joint J 2023;105-B(3):277–283

Aims. Periprosthetic joint infection (PJI) is a challenging complication of any arthroplasty procedure. We reviewed our use of static antibiotic-loaded cement spacers (ABLCSs) for staged management of PJI where segmental bone loss, ligamentous instability, or soft-tissue defects necessitate a static construct. We reviewed factors contributing to their failure and techniques to avoid these complications when using ABLCSs in this context. Methods. A retrospective analysis was conducted of 94 patients undergoing first-stage revision of an infected knee prosthesis between September 2007 and January 2020 at a single institution. Radiographs and clinical records were used to assess and classify the incidence and causes of static spacer failure. Of the 94 cases, there were 19 primary total knee arthroplasties (TKAs), ten revision TKAs (varus-valgus constraint), 20 hinged TKAs, one arthrodesis (nail), one failed spacer (performed elsewhere), 21 distal femoral endoprosthetic arthroplasties, and 22 proximal tibial arthroplasties. Results. A total of 35/94 patients (37.2%) had spacer-related complications, of which 26/35 complications (74.3%) were because of mechanical failure of the spacer construct, while 9/35 (25.7%) were due to recurrence of infection. Risk factors for internal failure were a construct where the total intramedullary spacer length was less than twice the length of the central osseous defect (p = 0.009), where proximal or distal intraosseous spacer contact was < 10%, and after tibial tubercle osteotomy (p = 0.005). The incidence of spacer complications significantly increased the time to second stage: mean 157 days (42 to 458) in those without complications versus 227 days (11 to 528) with complications (p = 0.014). Conclusion. The failure rate of static antibiotic-loaded cement spacers is much higher than anticipated. Complications of the spacer significantly increased the time to second-stage revision. The risk of mechanical failure is significantly increased if the spacer is less than double the size of the segmental defect, or if inadequate reinforcement is inserted into the residual bone. These findings serve as a guide for surgeons to avoid mechanical complications with static spacers. Cite this article: Bone Joint J 2024;106-B(10):1067–1073

Abstract. INTRODUCTION. The most frequent mode of aseptic failure of primary total knee replacements is tibial baseplate loosening. This is influenced by stresses across the implant-bone interface which can be increased in obese patients leading to potentially higher rates of early failure. The evidence is mixed as to the true effect of elevated BMI (body mass index) on revision rates. We present the experience of early tibial failures in our department and how our implant choices have evolved. METHODOLOGY. We retrospectively reviewed our unit's arthroplasty database and identified all patients who had sustained mechanical tibial failure. Data were collected on patient demographics, operative details of primary and revision operations, components used, alignment pre and post operatively and indication. Complications and further surgery performed were recorded. RESULTS. 12 patients were identified who had been revised for mechanical tibial failure. All were female, mean age 60 years (46–76). Mean BMI was 11/12 had significant comorbidities and 6/12 had risk factors for reduced bone density (inflammatory arthritis, diabetes, hypothyroid). CONCLUSION. In our consecutive series of 12 patients who presented with tibial mechanical failure, all were female and had a high BMI with the majority over 40. We recommend that a stemmed tibia construct should be used in female patients with an elevated BMI, particularly if it is over 40

Aims. Debate continues regarding the optimum management of periprosthetic distal femoral fractures (PDFFs). This study aims to determine which operative treatment is associated with the lowest perioperative morbidity and mortality when treating low (Su type II and III) PDFFs comparing lateral locking plate fixation (LLP-ORIF) or distal femoral arthroplasty (DFA). Methods. This was a retrospective cohort study of 60 consecutive unilateral (PDFFs) of Su types II (40/60) and III (20/60) in patients aged ≥ 60 years: 33 underwent LLP-ORIF (mean age 81.3 years (SD 10.5), BMI 26.7 (SD 5.5); 29/33 female); and 27 underwent DFA (mean age 78.8 years (SD 8.3); BMI 26.7 (SD 6.6); 19/27 female). The primary outcome measure was reoperation. Secondary outcomes included perioperative complications, calculated blood loss, transfusion requirements, functional mobility status, length of acute hospital stay, discharge destination and mortality. Kaplan-Meier survival analysis was performed. Cox multivariate regression analysis was performed to identify risk factors for reoperation after LLP-ORIF. Results. Follow-up was at mean 3.8 years (1.0 to 10.4). One-year mortality was 13% (8/60). Reoperation was more common following LLP-ORIF: 7/33 versus 0/27 (p = 0.008). Five-year survival for reoperation was significantly better following DFA; 100% compared to 70.8% (95% confidence interval (CI) 51.8% to 89.8%, p = 0.006). There was no difference for the endpoint mechanical failure (including radiological loosening); ORIF 74.5% (56.3 to 92.7), and DFA 78.2% (52.3 to 100, p = 0.182). Reoperation following LLP-ORIF was independently associated with medial comminution; hazard ratio (HR) 10.7 (1.45 to 79.5, p = 0.020). Anatomical reduction was protective against reoperation; HR 0.11 (0.013 to 0.96, p = 0.046). When inadequately fixed fractures were excluded, there was no difference in five-year survival for either reoperation (p = 0.156) or mechanical failure (p = 0.453). Conclusion. Absolute reoperation rates are higher following LLP fixation of low PDFFs compared to DFA. Where LLP-ORIF was well performed with augmentation of medial comminution, there was no difference in survival compared to DFA. Though necessary in very low fractures, DFA should be used with caution in patients with greater life expectancies due to the risk of longer term aseptic loosening. Cite this article: Bone Joint J 2021;103-B(4):635–643

Background. The purpose of this study was to evaluate the clinical and radiographic outcomes of the rotating-platform, posterior-stabilized PFC Sigma at fifteen-year follow-up. Methods. Between January 2000 and November 2001, two hundred consecutive patients underwent TKA with a rotating-platform, posterior stabilized total knee arthroplasty with cement. All patients have been followed prospectively and all patients with minimum 12 year follow up were included in this analysis. Forty-nine TKAs were available for our final analysis with a mean follow up of 16.0 years. Results. The improvements in Knee Society pain and function scores were 44 to 83. The 15-year Koos Jr interval scores for cohort was 76.2. The range of motion improved from 111° to 115°. The prevalence of residual pain was 32.5%, painless crepitation was 15% and 5% reporting painful crepitation at 15-year follow up via PROMs. Kaplan-Meier analysis revealed that the survivorship was 100% due to mechanical failure as an endpoint, and 95% as reoperation as an end-point. Conclusions. At fifteen-year follow up, the rotating-platform, posterior stabilized arthroplasty demonstrated excellent survivorship and radiographic results. Peripatellar crepitation, occasionally requiring excision, remains an issue. For figures, tables, or references, please contact authors directly

Aims

The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes.

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The aim of this study was to investigate the distribution of phenotypes in Asian patients with end-stage osteoarthritis (OA) and assess whether the phenotype affected the clinical outcome and survival of mechanically aligned total knee arthroplasty (TKA). We also compared the survival of the group in which the phenotype unintentionally remained unchanged with those in which it was corrected to neutral.

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With up to 40% of patients having patellofemoral joint osteoarthritis (PFJ OA), the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee via total knee arthroplasty (TKA). The aim of this study was to assess postoperative success of second-generation PFAs compared to TKAs for patients treated for PFJ OA using patient-reported outcome measures (PROMs) and domains deemed important by patients following a patient and public involvement meeting.

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The primary objective of this study was to compare the five-year tibial component migration and wear between highly crosslinked polyethylene (HXLPE) inserts and conventional polyethylene (PE) inserts of the uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary objectives included clinical outcomes and patient-reported outcome measures (PROMs).

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The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs).

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Both the femoral and tibial component are usually cemented at revision total knee arthroplasty (rTKA), while stems can be added with either cemented or press-fit (hybrid) fixation. The aim of this study was to compare the long-term stability of rTKA with cemented and press-fitted stems, using radiostereometric analysis (RSA).

This study describes 146 primary total knee replacements, either fully or partially coated with hydroxyapatite of which 74 knees in 68 patients were available for clinical and radiological assessment at a mean of 11.2 years (10 to 15). The global failure rate was 1.37% and survival rate with mechanical failure as the end-point was 98.14%. Radiological assessment indicated intimate contact between bone and the hydroxyapatite coating. Over time the hydroxyapatite coating appears to encourage filling of interface gaps remaining after surgery. Our results compare favourably with those of series describing cemented or porous-coated knee replacements, and suggest that fixation with hydroxyapatite is a reliable option in primary total knee replacement

Aims

Wear of the polyethylene (PE) tibial insert of total knee arthroplasty (TKA) increases the risk of revision surgery with a significant cost burden on the healthcare system. This study quantifies wear performance of tibial inserts in a large and diverse series of retrieved TKAs to evaluate the effect of factors related to the patient, knee design, and bearing material on tibial insert wear performance.

Limb alignment in total knee arthroplasty (TKA) influences periarticular soft-tissue tension, biomechanics through knee flexion, and implant survival. Despite this, there is no uniform consensus on the optimal alignment technique for TKA. Neutral mechanical alignment facilitates knee flexion and symmetrical component wear but forces the limb into an unnatural position that alters native knee kinematics through the arc of knee flexion. Kinematic alignment aims to restore native limb alignment, but the safe ranges with this technique remain uncertain and the effects of this alignment technique on component survivorship remain unknown. Anatomical alignment aims to restore predisease limb alignment and knee geometry, but existing studies using this technique are based on cadaveric specimens or clinical trials with limited follow-up times. Functional alignment aims to restore the native plane and obliquity of the joint by manipulating implant positioning while limiting soft tissue releases, but the results of high-quality studies with long-term outcomes are still awaited. The drawbacks of existing studies on alignment include the use of surgical techniques with limited accuracy and reproducibility of achieving the planned alignment, poor correlation of intraoperative data to long-term functional outcomes and implant survivorship, and a paucity of studies on the safe ranges of limb alignment. Further studies on alignment in TKA should use surgical adjuncts (e.g. robotic technology) to help execute the planned alignment with improved accuracy, include intraoperative assessments of knee biomechanics and periarticular soft-tissue tension, and correlate alignment to long-term functional outcomes and survivorship.

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The aim of this study was to measure the effect of hospital case volume on the survival of revision total knee arthroplasty (RTKA).

Mechanical failure because of wear or fracture of the polyethylene tibial post in posteriorly-stabilised total knee replacements has been extensively described. In this study of 12 patients with a clinically and radiologically successful NexGen LPS posteriorly-stabilised prosthesis impingement of the anterior tibial post was evaluated in vivo in three dimensions during gait using radiologically-based image-matching techniques. Impingement was observed in all images of the patients during the stance phase, although the NexGen LPS was designed to accommodate 14° of hyperextension of the component before impingement occurred. Impingement arises as a result of posterior translation of the femur during the stance phase. Further attention must therefore be given to the configuration of the anterior portion of the femoral component and the polyethylene post when designing posteriorly-stabilised total knee replacements

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The primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs).

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Varus-valgus constrained (VVC) implants are often used during revision total knee arthroplasty (TKA) to gain coronal plane stability. However, the increased mechanical torque applied to the bone-cement interface theoretically increases the risk of aseptic loosening. We assessed mid-term survivorship, complications, and clinical outcomes of a fixed-bearing VVC device in revision TKAs.

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It has been suggested that mobile-bearing total knee arthroplasty (TKA) might lead to better outcomes by accommodating some femorotibial rotational mismatch, thereby reducing contact stresses and polyethylene wear. The aim of this study was to determine whether there is a difference between fixed- and mobile-bearing versions of a contemporary TKA with respect to durability, range of movement (ROM) and function, ten years postoperatively.