Techniques and Technologies in Revision Knee Arthroplasty

The purpose of this study was to investigate if the type of approach [medial parapatellar approach (MPA) versus lateral parapatellar approach with tibial tubercle osteotomy (LPA)] influences rotation of femoral and/or tibial component and leg axis in total knee arthroplasty (TKA). It was the hypothesis that MPA leads to an internally rotated tibial TKA component. This study included 200 consecutive patients in whom TKA was performed using either a parapatellar medial (n=162, MPA) or parapatellar lateral approach with tibial tubercle osteotomy (n=38, LPA). All patients underwent clinical follow-up, standardized radiographs and computed radiography (CT). TKA components' position and the whole leg axis were assessed on 3D reconstructed CT scans (sagittal, coronal and rotational). Mean values of TKA component position and the whole leg alignment of both groups were compared using a t test. The tibial component was graded as internally rotated (<3° of external rotation (ER)), neutral rotation (equal or between 3° and 6° of ER) and externally rotated (>6° ER). The femoral component was graded as internally rotated [>3° of internal rotation (IR)], neutral rotation (equal or between -3° IR and 3° of ER) and externally rotated (>3° ER). There was no significant difference in terms of whole leg axis after TKA between both groups (MPA: 0.2° valgus±3.4; LPA: 0.0° valgus±3.5). Means of tibial component rotation were 2.7° ER±6.1 (MPA) and 7.6° ER±5.4 (LPA). Patients of group LPA presented a significantly less internally rotated (LPA: 18.4%; MPA: 48.8%) and more externally rotated (LPA: 52.6%; MPA: 22.8%) tibial component (p<0.001). No significant differences were seen for the femoral component position, tibial valgus/varus and tibial slope. The type of approach (medial versus lateral) significantly influenced tibial TKA component rotation. It appears that a MPA tends to internally rotate the tibial TKA component and a LPA tends to externally rotate the tibial TKA. The anterior cortex should not be used as landmark for tibial TKA component placement when using the lateral approach with tibial tubercle osteotomy. Retrospective comparative study, Level III.

Introduction The management of periprosthetic fractures is challenging and is guided by the configuration of the fracture, stability of implants and quality of the patient’s bone. This case report discusses the long-term fate of femoral allograft for periprosthetic fracture around a revision knee arthroplasty. Case report We present the operative technique and long-term fate of a bivalved femoral allograft used for the treatment of a periprosthetic fracture around a stemmed femoral component of a revision total knee arthroplasty (TKA) in a patient with rheumatoid arthritis and osteoporosis. Regular radiographic follow-up confirmed incorporation and docking of the allograft. A subsequent ipsilateral femoral neck fracture 4 years after allograft implantation was treated with routine total hip replacement. Conclusion The use of femoral allograft for augmenting fixation of periprosthetic fractures above a TKA is not widely reported, and, at 11 years, this case represents the longest published follow-up above a revision TKA. Our case supports the use of a bivalved total femoral allograft in the treatment of long-bone periprosthetic fractures with poor bone stock. Introduction Data from joint registries indicate an increase in the number of primary and revision knee arthroplasties being performed each year internationally, and the volume of revision knee arthroplasty being performed in the USA alone is expected to increase by 601% between 2005 and 20301. Periprosthetic supracondylar femoral fractures can occur intraoperatively and postoperatively, with an overall incidence of 0.3–2.5% above primary total knee arthroplasties (TKAs)2–7. Estimates of the incidence after revision knee arthroplasty vary greatly from 1.7% to 38%3,6–8, with most reports quoting closer to 2%. Periprosthetic femoral fractures above TKA and revision TKA have historically been associated with high complication rates when treated nonoperatively or with internal fixation4,5,9. Periprosthetic fractures are more common in the elderly population and in females7. Additional risk factors include rheumatoid arthritis, chronic steroid treatment, reduced bone stock, neurological disorders, revision surgery, notching of the anterior cortex of the femur, and in particular poor bone stock3,9–11. Primary osteopenia or secondary to stress shielding around a stemmed revision femoral component further increases the difficulty of achieving good fracture fixation by traditional methods. Whilst the introduction of locked plate technology has revolutionized surgery in the presence of osteoporotic bone12, the use of a combination of cortical femoral allograft and compression plate13 or a bivalved total femoral allograft5,14 may be indicated when a periprosthetic fracture around a well-fixed implant is complicated by deficient bone stock or significant comminution. Unfortunately, there remains insufficient evidence to strongly support the use of a single method of surgical treatment in this complex fracture group. In this case report, we aim to provide further evidence that a bivalved total femoral allograft can be successfully used in the treatment of periprosthetic femoral fractures above/around a well-fixed stemmed revision TKA and that incorporation of the graft with the host femur is possible thereby increasing the patient’s bone stock. This technique can provide a reliable long-term solution in this complex fracture group. Case report One month after primary TKA for valgus arthritis, a 60-year-old lady with polyarticular rheumatoid arthritis and severe osteoporosis re-presented with a sintering fracture of the lateral femoral condyle after a simple stumble. The femoral component was revised to an uncemented stemmed implant, and the lateral femoral condyle was reconstructed with femoral head structural allograft. Three months after discharge, she fell and sustained a spiral periprosthetic fracture around the femoral stem (Figure 1). * Corresponding author Email: gavin.macpherson@nhs.net 1 Department of Orthopaedic Surgery, The Royal Infirmary of Edinburgh, 51 Little France Crescent, Old Dalkeith Road, Edinburgh, EH16 4SA, UK 2 Stiftung Orthopadische Universitatsklinik, Schlierbacher Landstrase 200a, 69118 Heidelberg, Germany 3 Orthopadischen Klinik Paulinenhilfe, Diakonie Klinikum Stuttgart, Rosenbergstrasse 38, D-70176 Stuttgart, Germany 4 Endoklinik Hamburg, Holstenstr. 2, 22767 Hamburg, Germany

To Editor: A number of recent articles, including In Vivo Deterioration of Tibial Baseplate Locking Mechanisms in Contemporary Modular Total Knee Components (2001;83-A:1660-5), by Engh et al., and The Effectiveness of Isolated Tibial Insert Exchange in Revision Total Knee Arthroplasty (2002;84-A:64-8), by Babis et al., have discussed modularity of tibial components in total knee arthroplasty. Both of these studies mentioned the potential advantage of a reduction of implant inventory with use of modular components. We have not experienced these perceived benefits of modular tibial components in total knee arthroplasty. We currently have an inventory of both modular and nonmodular total knee arthroplasty systems. nonmodular system that we use is the AGC (Anatomic Graduated Components) Total Knee System (Biomet, Warsaw, Indiana). To have an adequate inventory for use in primary total knee arthroplasty, we maintain three patellar sizes; five tibial component sizes, each with seven corresponding polyethylene thicknesses; and five universal femoral components, which …

Outcome of prosthesis matched and unmatched patella components in primary and revision total knee replacement

The accuracy of computed tomography for determining femoral and tibial total knee arthroplasty component rotation

Introduction: The use of modular components provides several advantages in total knee arthroplasty (TKA), including exchange of the polyethylene insert while retaining the stable components in the revision TKA. Compared to full, non-modular component revision TKA, isolated polyethylene exchange (IPE) has the advantage of decreased morbidity, faster rehabilitation, and acceptable outcomes. Methods: A review of published literature on revision TKA was conducted, with a specific focus on studies evaluating the use of IPE for managing complications such as stiffness, instability, and periprosthetic joint infection (PJI). Results: IPE with downsizing may be considered for patients with mild stiffness and stable, well-positioned implants that have increased polyethylene thickness, though expectations for motion gain should be cautious. There is no clear consensus on IPE for instability. Some studies report high re-revision rates, while others show clinical and functional improvement when the TKA is well-aligned, well-fixed, and intraoperative gap balance is achieved. Additionally, irrigation and debridement with polyethylene exchange (IDPE) may be effective for acute TKA PJI management, particularly within the first two weeks of symptom onset. Conclusions: Based on current literature, IPE in aseptic TKA revisions may be effective for stiffness or instability when implants are well-fixed and well-aligned—particularly if polyethylene constraint can be adjusted for instability or downsized for stiffness. The role of IDPE in acute TKA PJI is better defined in the literature, with strong emphasis on its time-sensitive effectiveness—most notably within the first two weeks of symptom onset.

PurposeAnatomical rotational mismatch (ARM) refers to postoperative malrotation between the femur and tibia, and component rotational mismatch (CRM) refers to malrotation between the femoral and tibial components in total knee arthroplasty (TKA). This study aimed to quantify ARM and CRM and assess their individual and combined effects on postoperative outcomes.MethodsThis retrospective study analysed 224 knees that underwent primary TKA. Postoperative axial rotational angles between the femoral and tibial components (component rotational angle [CRA]) and between the femur and tibia (anatomical rotational angle [ARA]) were measured using computed tomography. Internal tibial or tibial component rotation relative to the femur or femoral component was assigned a positive value. Rotational mismatch was defined as CRA and ARA over ±10°. Clinical outcomes were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) 1 year postoperatively. Hierarchical cluster analysis categorised knees into two groups based on CRA and ARA (Groups 1 and 2).ResultsThe mean ± standard deviation (SD) postoperative ARA was 5.2° ± 5.3°, with ARM present in 16.1% of cases (36 knees). Knees with ARM showed significantly worse improvement in the KOOS pain subscale than those without ARM (p = 0.02). Postoperative CRA was 1.5° ± 4.5°, with CRM observed in 2.7% of cases (6 knees), but CRM alone did not significantly affect postoperative outcomes. Cluster analysis identified two groups (Group 1: 185 knees; Group 2: 39 knees), with Group 2 exhibiting greater CRAs and ARAs compared to Group 1 (both p < 0.01). Group 2 also had significantly worse KOOS pain and activities of daily living improvement relative to Group 1 (p < 0.01, 0.04).ConclusionsBoth CRM and ARM were observed following TKA. ARM negatively impacted postoperative outcomes, and the combined presence of CRM and ARM further worsened clinical results.Level of EvidenceLevel IV.

Outcomes in revision knee arthroplasty: Preventing reoperation for infection Keynote lecture - BASK annual congress 2023

Introduction Accuracy in the placement of components in revision total knee arthroplasty (R-TKA) surgery is sometimes challenging. The applicability of patient‑specific instruments (PSI) in knee surgery has progressively expanded to types of surgery other than primary arthroplasty. Could this assistive technology be used to facilitate accurate R-TKA surgery? The aim of the current manuscript is to describe this new application of PSI for revision of TKA-to-TKA and to provide a step-by-step technical guideline for use. Areas covered We will describe the application and a detailed description of PSI technology to TKA revision surgery, step-by-step, from CT images acquisition for preoperative planning and PSI blocks production to the surgery. Expert commentary The system can facilitate the accomplishment of the bony cuts for optimal implant placement and that can be useful in minimally altering the femoral and the tibial joint line. It is obvious that technology alone will not replace surgical skill and that accuracy of the system will also depend on the quality of the CT images and the ability of the software to prevent metal artifacts. Despite that, our initial results are promising and prove that the concept of applying PSI technology to the R-TKA surgery is feasible.

Rotational alignment of prosthetic components after total knee arthroplasty (TKA) is predominantly monitored with computer tomography (CT), for example by relating the anatomical transepicondylar axis (a-TEA) of the native femur to the posterior bicondylar axis of the prosthetic component (PBCA). The purpose of the present study was to portray a reliable, novel plain radiographic method that likewise enables the evaluation of rotational positioning of prosthetic components in TKA. Furthermore, it was intended to evaluate the prosthetic femoro-tibial functional behavior under loaded conditions. Modified plain axial radiographs under partial weight bearing (20kg) were performed in 63 patients (63 knees) after TKA. On the obtained radiographs, all established, relevant anatomic, and prosthetic axis and angles reflecting the rotational position of the femoral (i.e., a-TEA/PBCA angle) and tibial component were detected twice by two independent examiners with an interval of one month. Additionally, in 14 cases with anterior knee pain after surgery, radiographic results were compared to obtained computer tomography images; intraclass coefficients (ICC's) for intra- and inter-rater reliability were calculated. All pre-assigned axis and angles could be identified doubtlessly by both examiners in all investigated knees. For all measurements, ICC's for intra-rater and inter-rater reliability ranged from 0.75 to 0.96. The comparison of the radiographic measurements with corresponding CT results (n = 14) revealed no significant differences (p > 0.05). Rotational alignment of the tibial tray in relation to the native tibial bone was not measurable due to display overlaying. Femoro-tibial behaviour of the prosthetic components under partial loading showed a high variability. We were able to establish a new reliable radiographic technique that is able to show the most established and relevant anatomic landmarks and prosthetic axis after TKA to assess the rotational alignment of the prosthetic components in TKA in relation to the distal femur. The evaluation of the femoro-tibal behaviour instead shows a high variability and so far does not allow valid explanatory conclusions.

ObjectivesThe design of tibial trays for total knee arthroplasty (TKA) has been a topic of research for several decades. Although all-polyethylene trays were developed to address issues such as osteolysis and to enhance the longevity of the prosthesis, as well as knee range of motion, metal-backed designs have remained the most commonly used type of prosthesis. This meta-analysis aimed to compare the clinical, radiological, and survival outcomes of both designs.MethodsFive databases were searched from inception until October 1, 2020, for randomized controlled trials (RCTs) that compared the outcomes of all-polyethylene and metal-backed tibial components in TKA. The outcomes of interest included range of motion, knee society score, stairs climbing scores, radiostereographic analysis, survivorship and complication. This review was conducted in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Risk of bias was assessed using the Newcastle–Ottawa tool.ResultsA total of 14 RCTs with 1367 TKA were included with a mean age of – years and – years for all-polyethylene and metal-backed tibial components groups, respectively. All-polyethylene group demonstrated statistically significant differences in five-year survivorship (OR 0.27; 95% CI 0.10–0.75; p value 0.01) and stairs climbing score (OR − 2.07; 95% CI − 3.27–0.87; p value 0.0007) when compared to the metal-backed group. The metal-backed design was significantly more radiographically stable in anterior–posterior, varus–valgus, and internal–external rotations at the 2-year follow-up compared to all-polyethylene tibias (OR − 0.09; 95% CI − 0.16 to − 0.02; p value 0.02) as per the pooled radiostereographic analysis. However, ten-year survivorship (OR 0.92; 95% CI 0.53–1.60; p value 0.78), range of motion (OR − 0.57; 95% CI − 2.00–0.85, p value 0.43), knee society scores (OR 1.38; 95% CI − 0.47–3.23, p value 0.14), and complications (OR 0.83; 95% CI 0.5–1.39, p value 0.48) were comparable between both groups.ConclusionsWhile this meta-analysis suggests that all-polyethylene tibial components in total knee arthroplasty may offer advantages over metal-backed components in terms of five-year survivorship, and stairs climbing score, this finding should be considered in the context of potential confounding factors. Nonetheless, based on the results, the all-polyethylene implant should be considered a viable choice for primary knee replacement.Level of evidenceI.

Porous tantalum represents a relatively new solution for primary and revision total knee arthroplasty, offering several unmatched properties. Tantalum is a transition metal, with excellent biocompatibility and bioactivity due to its intrinsic physical and structural characteristics. A widespread clinical use of porous tantalum tibial components for primary total knee arthroplasty has been partly hindered by the difficulty in removing this type of implant after bone in growth, often leading to a significant bone defect. On the contrary, in the case here reported, removal of the trabecular metal tibial component was unexpectedly easy at a 7-month follow-up due to the absence of bone ingrowth but with a complete preservation of the tibial plate bone stock. Causes for the lack of bone ingrowth are discussed.

BackgroudIntravenous tranexamic acid (TXA) has been shown to reduce blood loss in patients undergoing total joint arthroplasty without systemic complications. There is limited evidence of its effectiveness in revision procedures. This study evaluated intravenous TXA effect on blood loss, transfusion rates, and length of hospital stay in revision joint replacement.MethodsOne-hundred revision total joint arthroplasty patients were retrospectively reviewed [44 revision total hip arthroplasty (THA) and 54 revision total knee arthroplasty (TKA)] who underwent surgery from 2013 to 2016. Fifty-four revision joint patients (23 THA and 31 TKA) received intravenous TXA intra-operatively, while 46 revision joint patients (23 THA/TKA) did not. Primary outcome measures were blood loss, transfusion rates, and length of hospital stay.ResultsThe mean blood loss difference between revision THA patients who received TXA vs. not receiving TXA was 180ml in revision THA patients (p < .005). Mean length of hospital stay was 6 days in non-TXA vs. 3 days in TXA patients (p < .001). Eighteen patients received transfusions in the non-TXA revision TKA group compared to nine patients in the TXA revision TKA group (p < .001). Average length of hospital stay was 5 days in the non-TXA revision TKA group compared to 3 days in the TXA revision TKA group (p < .003). There was no increased risk of thromboembolic complications in TXA groups for either procedure.ConclusionsIntravenous TXA reduced length of hospital stay in both revision cohorts, decreased blood loss in revision THA and decreased the rate of transfusion in revision TKA without an increase in thromboembolic complications.Level of EvidenceLevel III (Case-control study)

Thresholds of acceptable early migration of the components in total knee arthroplasty (TKA) have traditionally ignored the effects of patient and implant factors that may influence migration. The aim of this study was to determine which of these factors are associated with overall longitudinal migration of well-fixed tibial components following TKA. Radiostereometric analysis (RSA) data over a two-year period were available for 419 successful primary TKAs (267 cemented and 152 uncemented in 257 female and 162 male patients). Longitudinal analysis of data using marginal models was performed to examine the associations of patient factors (age, sex, BMI, smoking status) and implant factors (cemented or uncemented, the size of the implant) with maximum total point motion (MTPM) migration. Analyses were also performed on subgroups based on sex and fixation. In the overall group, only fixation was significantly associated with migration (p < 0.001). For uncemented tibial components in males, smoking was significantly associated with lower migration (p = 0.030) and BMI approached significance (p = 0.061). For females with uncemented components, smoking (p = 0.081) and age (p = 0.063) approached significance and were both associated with increased migration. The small number of self-reported smokers in this study warrants cautious interpretation and further investigation. For cemented components in females, larger sizes of tibial component were significantly associated with increased migration (p = 0.004). No factors were significant for cemented components in males. The migration of uncemented tibial components was more sensitive to patient factors than cemented implants. These differences were not consistent by sex, suggesting that it may be of value to evaluate female and male patients separately following TKA. Cite this article: Bone Joint J2022;104-B(4):444-451.

The aim of this retrospective cohort study was to investigate the reasons for total knee arthroplasty (TKA) revisions at a tertiary hospital over a four-year period. The study aimed to identify the primary causes of TKA revisions and shed light on the implications for patient care and outcomes.The study included 31 patients who underwent revisions after primary knee arthroplasty between January 2017 and December 2020. A retrospective approach was employed, utilizing medical records and radiological findings to identify the reasons for TKA revisions. The study excluded oncology patients to focus on non-oncologic indications for revision surgeries. Patient demographics, including age and gender, were recorded. Data analysis involved categorizing the reasons for revision based on clinical assessments and radiological evidence.Among the 31 patients included in the study, 9 were males and 22 were females. The age of the patients ranged from 43 to 81, with a median age of 65 and an interquartile range of 18.5. The primary reasons for TKA revisions were identified as aseptic loosening (10 cases) and prosthetic joint infection (PJI) (13 cases). Additional reasons included revision from surgitech hemicap (1 case), patella osteoarthritis (1 case), stiffness (2 cases), patella maltracking (2 cases), periprosthetic fracture (1 case), and patella resurfacing (1 case). The findings of this retrospective cohort study highlight aseptic loosening and PJI as the leading causes of TKA revisions in the examined patient population.These results emphasize the importance of optimizing surgical techniques, implant selection, and infection control measures to reduce the incidence of TKA revisions. Future research efforts should focus on preventive strategies to enhance patient outcomes and mitigate the need for revision surgeries in TKA procedures.