Metaphyseal Sleeves Research Articles

Clinical outcomes of primary total knee arthroplasty in non-syphilitic neuroarthropathy of the knee.

Total knee arthroplasty (TKA) in syphilitic neuroarthropathy using earlier implant designs was associated with poorer outcomes. Literature on TKA for non-syphilitic neuroarthropathy using modern contemporary prosthesis is scarce. We aim to analyse the clinical and radiological outcomes of TKA in neuropathic joints. A final cohort of 17 patients (21 knees) with the diagnosis of neuropathic joint undergoing primary TKA between January 2013 to January 2019 were included in the study. The preoperative ambulatory status, range of motion, type of prosthesis, level of constraint and any augmentation used were retrieved from medical records. Radiological evaluation includes Koshino's staging, the magnitude of deformity defined by the Hip-Knee-Ankle (HKA) angle, and any progressive loosening. Pre and postoperative functional scores were obtained by the Knee Society (KSS) and Knee Society Functional Score (KSS-F). Any complications or reoperation were noted till the final follow-up. Preoperative and follow-up functional scores, HKA and range of motion were compared using the paired Samples test. The mean follow-up was 40.2 months (range, 15 to 75 months). Preoperatively, according to the Koshino staging, five knees were in stage 3 (23.8%). The mean HKA angle in valgus knees was 23.60 (range, 11.10 to 42.50) and for the varus knees was 19.30 (range, 4.90 to 39.60). The prosthesis used were posterior stabilized in 7 knees (33.3%), varus-valgus constrained in five knees (23.8%) and a rotating hinge was required in nine knees (42.8%). Metaphyseal sleeves were used along with hinge prosthesis in six knees (28.6%). The mean arc of motion improved from 102.4 ± 22.7 degrees to 105.7 ± 15.5 degrees postoperatively (p = 0.27). The knee society and knee society functional scores improved from 23.3 ± 9.3 and 28.3 ± 12.2 preoperatively to 81.1 ± 5.4 and 80.4 ± 8.5 during the follow up respectively (p < 0.001). There were no progressive radiolucent lines in any knees at the final follow-up. One patient had intraoperative bony medial collateral ligament injury, one patient had deep vein thrombosis after five days from the index surgery and another had postoperative periprosthetic tibial shaft fracture. According to our study, the clinical outcomes of TKA for neuroarthropathy show significant improvement with the diagnosis of non-syphilitic neuroarthropathy, utilization of modern constrained prostheses, and early rehabilitation, at medium-term follow-up. Tibial and femoral stems are preferred for equal stress distribution and to prevent early loosening.

Mid-term Survivorship and Functional Outcomes of Metaphyseal Sleeves for Addressing Anderson Orthopaedic Research Institute (AORI) Type 2 and 3 Bone Defects in Revision Total Knee Arthroplasty.

Introduction Revision Total Knee Arthroplasty (RTKA) is a complex procedure challenged by significant bone loss, necessitating effective restoration techniques. This study investigates the clinical outcomes and complications of metaphyseal sleeves in RTKA with severe metaphyseal bone loss, aiming to evaluate their efficacy over a minimum four-year follow-up. Methods This was a retrospective observational study on 29 patients who underwent RTKA with Anderson Orthopaedic Research Institute (AORI) type II or III bone defects using porous coated tibial and/or femoral metaphyseal sleeves from December 2016 and January 2019. Data collection included demographic information, etiology for revision, and functional outcomes assessed by the Knee Society Score (KSS) and Oxford Knee Score (OKS). Statistical analysis and Kaplan-Meier survival analysis were performed. Results The cohort comprised patients with a mean age of 62.6 years (SD=7.8), predominantly female (N=21, 71.4%). The primary indication for RTKA was aseptic loosening (N=18, 62.1%) followed by Prosthetic Joint Infection (PJI). Significant improvements were noted in the range of motion. Both KSS (Pre-op:57.97 vs. Post-op:73.59) and OKS (Pre-op:15.86 vs. Post-op:30.66) showed highly significant improvement (p<0.0001). Radiographic assessments indicated stable component position and signs of osseous integration without any osteolysis. No sleeve-related complications were observed. Survival analysis demonstrated a high cumulative survival probability over the study period. Conclusion Metaphyseal sleeves offer a viable solution for managing severe bone loss in RTKA, providing stable fixation, restoring joint line kinematics, and facilitating stress distribution to the metaphyseal region. This study corroborates the effectiveness of metaphyseal sleeves in challenging revision scenarios, aligning with previous research.

Comparison of Novel 3D-printed Stepped Porous Metal Cones and Metaphyseal Sleeves for Reconstruction of Severe Knee Bone Defects: Short-term Clinical Outcomes.

Both porous metal cones and metaphyseal sleeves are excellent implants for reconstructing severe bone defects in the knee joint, but they both exhibit design limitations. The porous metal cone, especially, has significant room for improvement in its shape design. The existing porous metal cones often feature a conical external surface with a relatively small taper, potentially compromising both rotational and axial stability. To improve both axial and rotational stability in porous metal cones, we developed a 3D-printed stepped porous metal cone. This study aimed to assess the short-term clinical outcome of the 3D-printed stepped porous metal cone and to compare it with the clinical outcome of patients who underwent revision total knee arthroplasty (rTKA) with the metaphyseal sleeves during the same period. Patients who underwent total knee arthroplasty revision with metaphyseal bone defect reconstruction from 2019 to 2021 were retrospectively analyzed. A total of 61 patients were enrolled in the study, including 15 patients using 3D-printed stepped porous metal cones and 46 patients using metaphyseal metal sleeves. Thirty patients using metaphyseal sleeves were screened by propensity score matching method and compared with those using stepped cones. Analysis included the American Knee Society Score, the Hospital for Special Surgery knee score, the Western Ontario and McMaster Universities Arthritis index, the Short Form 12 (SF-12) health survey, and radiographic assessment with a mean follow-up of 28.5 ± 8.3 months. To conduct comparative analyses, unpaired Student's t-tests were employed for continuous variables, while categorical variables were analyzed using the appropriate Fisher exact or chi-squared test. In this study, the survival rates of both the stepped cone and metaphyseal sleeve were 100%. There was no statistically significant difference in postoperative knee function scores between the two groups (p > 0.05). However, patients in the cone group had significantly higher mental component summary scores on the SF-12 scale (p < 0.05) and higher increases in mean postoperative physical component summary scores than patients in the sleeve group (p < 0.05). In addition, patients in the cone group experienced fewer intraoperative and postoperative complications compared to the sleeve group. The 3D-printed stepped porous metal cone can effectively reconstruct bone defects in complex rTKA and provide satisfactory early clinical and radiographic results. The 3D-printed stepped cone provides a more stable structure similar to the sleeve while maintaining the original benefits of the cone making it a promising choice for rTKA.

Mid-term survivorship and clinical outcomes of revision knee arthroplasty using a mobile bearing tibial tray: A single-center registry review

BackgroundRevision total knee arthroplasty can successfully restore function and relieve pain for patients with failed knee replacements. Mobile-bearing implants were designed to provide greater congruency between the implant and the polyethylene insert. The goal of this study was to review the clinical outcomes and survivorship for a revision mobile-bearing tibial design. MethodsA retrospective outcomes review was conducted to assess survivorship and clinical outcomes for a mobile bearing tibial tray, used with metaphyseal sleeves, in revision total knee arthroplasty. ResultsAt time of furthest follow-up, KM estimates (95% CI; n with further follow-up) for all-cause revision were 82.5% (75.8%; 87.5%; 42) at 7 years for the clinical assumption (CA), and 88.5% (84.4%,91.6%; 53) at 13 years for the registry assumption (RA). For revision of the tray as the endpoint, survivorship estimates were 93.4% (87.0%,96.7%; 42) at 7 years for CA, and 96.2% (93.2%,97.9%; 53) at 13 years for RA. ConclusionIn this single-center registry evaluation, we found excellent mid-term survivorship and clinical outcomes for a mobile-bearing tibial tray used with metaphyseal sleeves in revision total knee arthroplasty.

Metaphyseal Fixation Using Cones and Sleeves for Severe Proximal Tibial Bone Loss

BackgroundTibial bone defects are commonly encountered in revision total knee arthroplasty (rTKA) and can be managed with metaphyseal cones or sleeves. Few studies have directly compared tibial cones and sleeves in rTKA, and none have limited this comparison to the most severe tibial defects. The purpose of this study was to evaluate and compare the outcomes of metaphyseal cones and sleeves for tibial reconstruction in rTKA regarding implant fixation and clinical outcomes. MethodsA retrospective review was conducted on patients undergoing rTKA in which metaphyseal cones or sleeves were utilized for addressing metaphyseal bone loss (34 cones and 18 sleeves). Tibial bone loss was classified according to the Anderson Orthopaedic Research Institute bone defect classification, with types 2B and 3 being included. Patient-reported outcomes and postoperative complications were collected, and a radiographic evaluation of osseointegration or loosening was performed. ResultsThere were 52 knees included (34 cones, 18 sleeves), with a median follow-up of 41.0 months. All-cause implant survival was 100% at 2 years and 96% (95% confidence interval: 76 to 99%) at 4 years, with 98% of tibial components demonstrating osseointegration at the final follow-up. During follow-up, there were a total 11 revisions, of which 1 sleeve was revised secondary to implant loosening. Tibial sleeves had a higher risk of revision compared to tibial cones (P < .01), and sleeves fixed with a hybrid technique were more likely to need revision than cones fixed by the same method (P = .01). ConclusionsPorous metaphyseal tibial cones and tibial metaphyseal sleeves both performed well at a 41-month median follow-up with no difference in aseptic survivorship between the 2 constructs. Both demonstrate high rates of osseointegration, low rates of aseptic failure, and significant improvement in Knee Society Scores in patients with severe tibial defects in rTKA.

Arthrodesis following persistent periprosthetic knee infection using femoral condyle allograft: a case report and review of literature

Periprosthetic joint infections (PJI) of the knee are difficult to treat and can require costly and prolonged hospital stays, weeks or months of antibiotic therapy, and multiple surgical procedures. Knee arthrodesis is considered a last resort for persistent knee joint infections and provides stability and pain relief by fusing the knee joint. The authors describe a case of a persistent and difficult to treat periprosthetic total knee arthroplasty (TKA) infection, subjected to multiple surgeries and revisions, where an arthrodesis was performed as a last resort. The arthrodesis was performed using a femoral-tibial endomedullary nail with interposed femoral condyle allograft. Complete graft integration and consolidation was achieved without complications. The patient performed well post-operatively and is currently ambulatory with walking aids and has no knee pain. The removal of well-fixed metaphyseal sleeves in TKA can be challenging and associated with complications such as damage to the surrounding bone and soft tissue during the removal process. Taking special care and not rushing this step can present an extremely meaningful difference in the final outcome. In cases with large bone defects, especially after sleeve removal, allograft usage can be extremely useful for managing dead space and limb-length discrepancies while promoting faster bone healing. When successful, as was the case described, arthrodesis using allografts can have beneficial outcomes with high patient satisfaction and deliver function to previously very unhealthy joints and limbs.

How to remove a well-fixed metaphyseal sleeve in revision knee arthroplasty: A step-by-step surgical procedure

BackgroundThe rising incidence and complexity of revision knee arthroplasty has led to an increase in the use of metaphyseal reconstruction systems. One of the most widely used systems are metaphyseal sleeves as they have demonstrated excellent long-term survival. However, there is concern about the possible difficulty of extracting a sleeve if it were necessary, as no known procedures have yet been validated. MethodsWe examined the outcomes of removing 23 well-integrated metaphyseal sleeves using the same systematized technique. ResultsAll sleeves were extracted without any intraoperative complications. Four subjects required an osteotomy to complete the extraction, while 62% of the sample were found to have an AORI IIB defect. All cases were successfully reconstructed with a new metaphyseal fixation, implanting a new sleeve in 38% of subjects compared with cones in the remaining 62%. ConclusionsThe technique described here produced successful, reproducible outcomes for the removal of integrated metaphyseal sleeves with minimal bone loss and no intraoperative complications.

BORS/BJR TRAVELLING FELLOWSHIP ABSTRACT: THE EFFECT OF INCREASING BONE LOSS ON THE PRIMARY STABILITY OF METAPHYSEAL SLEEVES IN THE PROXIMAL TIBIA. AN EXPERIMENTAL STUDY USING SAWBONE TIBIAS

AbstractApproximately 20% of primary and revision Total Knee Arthroplasty (TKA) patients require multiple revisions, which are associated with poor survivorship, with worsening outcomes for subsequent revisions. For revision surgery, either endoprosthetic replacements or metaphyseal sleeves can be used for the repair, however, in cases of severe defects that are deemed “too severe” for reconstruction, endoprosthetic replacement of the affected area is recommended. However, endoprosthetic replacements have been associated with high complication rates (high incidence rates of prosthetic joint infection), while metaphyseal sleeves have a more acceptable complication profile and are therefore preferred. Despite this, no guidance exists as to the maximal limit of bone loss, which is acceptable for the use of metaphyseal sleeves to ensure sufficient axial and rotational stability. Therefore, this study assessed the effect of increasing bone loss on the primary stability of the metaphyseal sleeve in the proximal tibia to determine the maximal bone loss that retains axial and rotational stability comparable to a no defect control.Methodsto determine the pattern of bone loss and the average defect size that corresponds to the clinically defined defect sizes of small, medium and large defects, a series of pre-operative x-rays of patients with who underwent revision TKA were retrospectively analysed. Ten tibiae sawbones were used for the experiment. To prepare the bones, the joint surface was resected the typical resection depth required during a primary TKA (10mm). Each tibia was secured distally in a metal pot with perpendicular screws to ensure rotational and axial fixation to the testing machine. Based on X-ray findings, a fine guide wire was placed 5mm below the cut joint surface in the most medial region of the plateau. Core drills (15mm, 25mm and 35mm) corresponding to small, medium and large defects were passed over the guide wire allowing to act at the centre point, before the bone defect was created. The test was carried out on a control specimen with no defect, and subsequently on a Sawbone with a small, medium or large defect. Sleeves were inserted using the published operative technique, by trained individual using standard instruments supplied by the manufacturers. Standard axial pull-out (0 – 10mm) force and torque (0 – 30°) tests were carried out, recording the force (N) vs. displacement (mm) curves.ResultsA circular defect pattern was identified across all defects, with the centre of the defect located 5mm below the medial tibial base plate, and as medial as possible. Unlike with large defects, small and medium sized defects reduced the pull-out force and torque at the bone-implant interface, however, these reductions were not statistically significant when compared to no bony defect.ConclusionsThis experimental study demonstrated that up to 35mm radial defects may be an acceptable “critical limit” for bone loss below which metaphyseal sleeve use may still be appropriate. Further clinical assessment may help to confirm the findings of this experimental study. This study is the first in the literature to aim to quantify “critical bone loss” limit in the tibia for revision knee arthroplasty.Declaration of Interest(a) fully declare any financial or other potential conflict of interest

Metaphyseal Metal Sleeves for Reconstruction of Severe Knee Bone Defects: Excellent Survival Rate at a Mean Follow-Up of 6.4 Years.

Management of bone loss in complex primary and revision total knee arthroplasty is key to the surgeries. Metaphyseal metal sleeves have been increasingly used recently to reconstruct severe knee metaphyseal bone defects. This study aimed to investigate the outcomes of the metaphyseal sleeve reconstructing Anderson Orthopedic Research Institute (AORI) type II and type III bone defects of knee joint. From 2014 to 2019, a total of 44 knees were enrolled in this clinical retrospective study after the screening, including seven cases of primary TKA and 37 cases of revision TKA. The types of bone defects involved in this study were AORI types II and III, and did not involve AORI type I bone defects. Patients' knee function preoperatively and postoperatively as well as quality of life were recorded and analyzed. Analysis included the American Knee Society Score (KSS), hospital for special surgery knee score (HSS), the Western Ontario and McMaster Universities (WOMAC) index, the Short Form 12 (SF-12) health survey, visual analogue scale score, and radiographic assessment with a mean follow-up of 6.4 years. Paired t-tests were used to determine the significance of changes in clinical scores and knee mobility. A mean follow-up of 77.2 (±17.6, standard deviation [SD]) months was performed, and none of the patients underwent knee revision for infection or aseptic loosening. At the last follow-up, the KSS knee score changed statistically from 37.1 (±19.7) preoperatively to 86.5 (±13.6, SD, p < 0.001) postoperatively and the KSS function score from 32.7 (±24.0) preoperatively to 78.3 (±15.6, SD, p < 0.001) postoperatively. The knee mobility improved from a mean of preoperative 72.61° (±33.42°, SD) to 108.52° (±24.15°, SD, p < 0.001). Postoperative radiographs showed that the host bone was tightly integrated with the metaphyseal metal sleeve, and there was no obvious translucent line formation around the sleeve. Of the patients, 86.4% had a postoperative satisfaction score ≥8 (10-point scale). At the mean follow-up of 6.4 years, the survival rate of the metaphyseal sleeves was 100%. Metaphyseal sleeves combined with cementless stems is an excellent and viable option for reconstruction of AORI type II and type III bone defects of the knee.

1244 Wound Dehiscence and Infection of a Total Knee Replacement Secondary to Postoperative ‘Dorsal Fin’ Intra-Articular Vertical Patella Dislocation

Abstract A 75-year-old man presented to our emergency department with a bleeding wound 19 days following a primary hinged left total knee replacement, performed elsewhere, for lateral tibiofemoral osteoarthritis. Examination revealed a knee held in fixed flexion of 30°, with partial dehiscence of the wound, implant exposure and a visible patella. Radiographs revealed an abnormally raised joint line with a vertical appearance of the patella on the lateral image. The decision was made to proceed with a two-stage revision. At operation, the patella was confirmed to be vertically positioned in the trochlea groove of the femoral component and identified as the likely cause for the wound dehiscence. There was evidence of a large lateral release having been performed during the primary surgery. A joint orthoplastic wound debridement was performed, together with implant removal, and static cement spacer insertion. Following an eight-week interval of IV antibiotics, the second stage was performed. A new hinged implant was implanted, with metaphyseal sleeves and stems. A tibial tubercle osteotomy was required to address the lateral tracking patella and a gastrocnemius flap was necessary to address a distal soft tissue defect. This case study highlights an unusual cause for wound dehiscence following total knee arthroplasty. Patella dislocation with vertical axis rotation has been described in the native knee1, but to our knowledge, this is the first report of this phenomenon following arthroplasty. This was almost certainly secondary to component malpositioning and emphasizes the significance of restoring the native joint line and correct implant rotation during knee replacement surgery.

Revision of total knee arthroplasty with press-fit condylar SIGMA TC3-mobile bearing system and porous metaphyseal sleeves in type AORI type II and III bone defects. A long-term follow-up study.

Revision total knee arthroplasty(rTKA) is a challenging and expensive treatment for orthopedic surgeons who have to deal with poor bone quality and bone loss. This study aims to retrospectively evaluate the clinical and radiological results of patients undergoing rTKA and porous metaphyseal sleeves in AORI type II and III bone defects. We conducted a retrospective series of continuous patients treated for mechanical failure of TKA. All patients with aseptic loosening of TKR underwent revision arthroplasty. We included only patients with AORI type IIa/b and III bone defects. The Septic revision or other grades of bone defect or patients lost at follow-up or with less than 2 years follow-up were excluded. We evaluated knee function with Oxford Knee Score (OKS) pain with Visual Analogue Scale (VAS) and range of motion (flex-ext), while radiological evaluation was performed to evaluate any sign of loosening. The mean preoperative OKS was 13.85 +/- 5.39 (range 5 -22), and it improved to 33.89 +/- 3.98 (range 20 - 40) (p<0.00001). The mean preoperative VAS was 7.77 +/- 1.33 (range 5 - 9), and it improved to 1.89 +/- 0.92 (range 0 - 4) (p<0.00001). ROM improved from 62.23° +/- 13.71° (range 40° - 90°) to 100.53° +/- 6.93° (range 90° - 120°) (p<0.00001). No signs of loosening or implant migration were reported. Metaphyseal sleeves made knee revision in large bone defects reliable and effective with good results. Good implant stability was reached in all the cases treated with metaphyseal sleeves.

Custom-Made Metaphyseal Sleeves in "Beyond" AORI III Defects for Revision Knee Arthroplasty-Proof of Concept and Short-Term Results of a New Technique.

While off-the-shelf cones and sleeves yield good results in AORI type 2 and 3 defects in revision knee surgery, massive longitudinal defects may require a proximal tibia replacement. To achieve the best anatomical as well as biomechanical reconstruction and preserve the tibial tuberosity, we developed custom-made metaphyseal sleeves (CMSs) to reconstruct massive defects with a hinge knee replacement. Between 2019 and 2022, 10 patients were treated in a single-center study. The indication for revision was aseptic loosening in five cases and periprosthetic joint infection in five cases. The mean number of previous revisions after the index operations was 7 (SD: 2; 4-12). A postoperative analysis was conducted to evaluate the functional outcome as well as the osteointegrative potential. Implantation of the CMS in rTKA was carried out in all cases, with a mean operation time of 155 ± 48 (108-256) min. During the follow-up of 23 ± 7 (7-31) months, no CMS was revised and revisions due to other causes were conducted in five cases. Early radiographic evidence of osseointegration was recorded using a validated method. The postoperative OKS showed a significant increase (p < 0.001), with a mean score of 24 (SD: 4; range: 14-31). Custom-made metaphyseal sleeves show acceptable results in extreme cases. As custom-made components become more and more common, this treatment algorithm presents a viable alternative in complex rTKA.

Comparative evaluation of bone defect substitution in revision knee arthroplasty

Objective: to evaluate the immediate and long-term outcomes of revision knee replacement using porous metaphysical sleeves and cones. Material and methods. The research involved 134 patients who underwent revision arthroplasty of their knee joints. The patients were divided into two groups according to the type of metaphyseal fixator: sleeves (Group 1) — 97 patients, and cones (Group 2) — 37 patients. The evaluation of the surgical outcomes was carried out at discharge from the hospital (in 7-12 days) as well as 6, 12, and 24 months after their surgeries. The survival rate of the implants was analyzed by the Kaplan — Meyer method. A revision with total replacement of the implant or its components was considered to be a critical event. Results. The analysis of the survival rate of the implants using various metaphysical fixators showed that the groups with metaphyseal sleeves and cones do not differ statistically (Log Rank criterion (Mantel — Cox) p=0.108). Conclusion. The medium term follow-up revealed no difference in clinical, functional or radiological outcomes of revision knee arthroplasty using porous cones or metaphyseal sleeves in 2A, 2B, and 3 (by Anderson Orthopaedic Research Institute classification) bone loss replacements.

Comparative evaluation of bone defect replacement methods in revision total knee arthroplasty

Objective: to evaluate the immediate and long-term outcomes of revision total knee arthroplasty using porous metaphyseal sleeves and cones. Materials and Methods. The study included 134 patients who underwent revision total knee arthroplasty. The patients were distributed among two groups based on the type of metaphyseal fixator: sleeves (Group I, n=97 patients) and cones (Group II, n=37 patients). Surgical outcomes were assessed upon discharge from the hospital (after the hospital stay of 7-12 days), as well as after 6, 12 and 24 months after surgery. The survival rate of endoprostheses was analyzed using the Kaplan–Meier method. A revision with total replacement of the endoprosthesis or its components was considered a critical event. Results. The analysis of the survival rate of endoprostheses in the form of various metaphyseal fixators showed that the groups of sleeves and cones did not differ statistically significantly as suggested by the logrank test (Mantel–Cox): p=0.108. Conclusion. The midterm follow-up revealed no difference in clinical, functional, or radiological outcomes of revision total knee arthroplasty performed for types 2A, 2B, and 3 of bone defect replacement (sensu Anderson Orthopaedic Research Institute classification) using trabecular metal metaphyseal cones vs. sleeves.

Замещение дефектов бедренной и большеберцовой костей при ревизионном эндопротезировании коленного сустава с применением не биодеградируемых материалов: обзор литературы.

In order to restore the function of the knee joint in the terminal stages of arthrosis, primary total knee arthroplasty is used. Primary total knee arthroplasty consists in replacing the femoral and tibial (in some cases, patellar) components of the knee joint with metal and polyethylene (ceramics are used in some types of endoprostheses). This operation has established itself as a method that improves the function of the knee joint in the later stages of gonarthrosis. But in cases of development of aseptic instability of the endoprosthesis components or septic instability of the endoprosthesis components due to periprosthetic infection, it is necessary to resort to revision arthroplasty. During revision arthroplasty, there are frequent cases of the formation of defects in the femur and tibia, which can become an obstacle to stabilization and return of knee joint function. To replace such defects at the present stage, the following methods are used, which relate to non-biodegradable materials: cementing, cementing with screw reinforcement, factory cement spacers with augments, modular metal augments, metaphyseal bushings with pressed porous titanium coating and structural cones made of porous tantalum, megaendoprostheses or individual endoprostheses. This review article analyzes sources describing methods for replacing defects in the bones forming the knee joint during revision knee arthroplasty and consisting of non-biodegradable materials from the PubMed, Google Scholar, SCOPUS, Web of Science databases. The analyzed methods of bone defect replacement are widely used in everyday practice, but also have a number of disadvantages. The use of thick layers of bone cement increases the risk of thermal necrosis and worsens the pressure of bone cement. Factory cement spacers with augment allow only the full defect of the plateau to be replaced. Modular metal augments are associated with corrosion and the development of instability. Metaphyseal bushings and structural cones can cause bone fracture upon insertion and are difficult to remove during revision. Mega endoprostheses or individual endoprostheses are associated with a high risk of infection. Modular metal augments, metaphyseal sleeves, structural cones, mega endoprostheses or individual endoprostheses also have a high cost. At this time, there is a need to develop new methods of defect replacement that will improve the function of the knee joint, improve the quality of life of patients, will be widely available and cost-effective.

Замещение дефектов бедренной и большеберцовой костей при ревизионном эндопротезировании коленного сустава с применением не биодеградируемых материалов

In order to restore the function of the knee joint in the terminal stages of arthrosis, primary total knee arthroplasty is used. Primary total knee arthroplasty consists in replacing the femoral and tibial (in some cases, patellar) components of the knee joint with metal and polyethylene (ceramics are used in some types of endoprostheses). This operation has established itself as a method that improves the function of the knee joint in the later stages of gonarthrosis. But in cases of development of aseptic instability of the endoprosthesis components or septic instability of the endoprosthesis components due to periprosthetic infection, it is necessary to resort to revision arthroplasty. During revision arthroplasty, there are frequent cases of the formation of defects in the femur and tibia, which can become an obstacle to stabilization and return of knee joint function. To replace such defects at the present stage, the following methods are used, which relate to non-biodegradable materials: cementing, cementing with screw reinforcement, factory cement spacers with augments, modular metal augments, metaphyseal bushings with pressed porous titanium coating and structural cones made of porous tantalum, megaendoprostheses or individual endoprostheses. This review article analyzes sources describing methods for replacing defects in the bones forming the knee joint during revision knee arthroplasty and consisting of non-biodegradable materials from the PubMed, Google Scholar, SCOPUS, Web of Science databases. The analyzed methods of bone defect replacement are widely used in everyday practice, but also have a number of disadvantages. The use of thick layers of bone cement increases the risk of thermal necrosis and worsens the pressure of bone cement. Factory cement spacers with augment allow only the full defect of the plateau to be replaced. Modular metal augments are associated with corrosion and the development of instability. Metaphyseal bushings and structural cones can cause bone fracture upon insertion and are difficult to remove during revision. Mega endoprostheses or individual endoprostheses are associated with a high risk of infection. Modular metal augments, metaphyseal sleeves, structural cones, mega endoprostheses or individual endoprostheses also have a high cost. At this time, there is a need to develop new methods of defect replacement that will improve the function of the knee joint, improve the quality of life of patients, will be widely available and cost-effective

Cementless Porous-Coated Metaphyseal Sleeves Used for Bone Defects in Revision Total Knee Arthroplasty: Short- to Mid-Term Outcomes.

While many studies have presented excellent short-term outcomes of the metaphyseal sleeves used in revision total knee arthroplasty (TKA), currently published mid-term results remain limited and some controversial issues remain unresolved. The purpose of this study was to investigate clinical and radiographic mid-term outcomes of the sleeves for the management of metaphyseal bone defects in revision TKAs. From 2015 to 2019, 44 patients (45 knees) who were operated with cementless porous-coated metaphyseal sleeve in revision TKA were included in this study. Bone defects were assessed according to Anderson Orthopaedic Research Institute Classification. On the tibial side, there were 37 type II and six type III, and with regards to the femur, 15 were type II, and four were type III. Through reviewing electronic records, data were collected, including baseline demographics, operative details, information of prothesis, and complications. Clinical and radiographic evaluations were performed, including Knee Society Scores (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), range of motion (ROM), the radiolucent line, level of joint line, and implant survival rate. Statistical analysis was performed by paired t-test for clinical and radiographic indexes. The mean follow-up time was 4.4 ± 1.4 years. During surgery, sleeve-related fractures were encountered in four (8.9%) knees, including incomplete tibial fracture of lateral cortex in one knee and of medial cortex in two knees, and longitudinal femoral metaphyseal fracture in one knee. Unions were achieved in all cases at the final follow-up. Significant improvements in KSS and WOMAC scores were found at the final follow-up, respectively, from 83.8 ± 29.1 to 152.9 ± 31.0 (t=-12.146, p < 0.001) and from 148.4 ± 42.3 to 88.1 ± 52.5 (t=6.025, p < 0.001). The mean ROM improved from 88.7 ± 31.9° to 113.7 ± 13.7° (t=-5.370, p < 0.001). A 75 mm length of cementless stem was used in all patients and only one patient was identified as tibial end-of-stem pain. No sleeve-related revision occurred, and one patient was diagnosed with early postoperative infection and was treated with irrigation and debridement, polyethylene liner exchange, and appropriate antibiotic treatment. The overall implant survival was 97.8% with the endpoint reoperation and 100% with the endpoint revision. Osseointegration at the bone-sleeve interface was found in all patients and no loosening happened. Satisfactory alignment between 3° varus and 3° valgus was achieved in all but not in three patients. The use of metaphyseal sleeves in the treatment of bone defects in rTKAs can provide stable fixation and significantly improve the clinical scores at the midterm follow-up. In addition, the rare occurrence of end-of-stem pain suggests routine use of cementless stems. Although there are chances of intraoperative fractures, it has no negative effect on outcome when managed properly.

Metaphyseal fixation in revision knee arthroplasty: a systematic review of the literature and meta-analysis of mid-long-term outcomes of metaphyseal sleeves and cones.

Metaphyseal augmentation has in recent years formed a key strategy in management of bone loss in revision knee arthroplasty. There are studies reporting excellent short-term results, however long- term data is lacking. There is also a paucity of studies comparing the most frequently utilised augments, metaphyseal sleeves, and cones. We conducted a systematic review and meta-analysis to evaluate and compare the mid to long term outcomes of metaphyseal cones and sleeves. We conducted systematic search of 4 databases (Medline, Embase, CINALH and PubMed). Seventeen studies were found to be eligible for inclusion of which ten investigated metaphyseal sleeves and the remaining seven investigated cones. Mean follow up across all studies was 6.2 years. The total number of patients included in the studies was 1319 and the number of knees operated on was 1431. We noted a higher revision rate of metaphyseal cones when compared to sleeves 10.85% vs 6.31 (p=0.007). Reoperation rates were also higher in cones compared to sleeves, 13.78% vs 3.68% (p<0.001). Prosthetic joint infection was the most common reason for revision. The difference in conversion rates, based on augment location was statistically significant p=0.019. When undertaking further sub-analysis; there was no statistically significant difference when comparing revision rates of; tibial vs femoral augments p=0.108, tibial vs tibial & femur p=0.54 but a difference was seen between femoral vs tibial & femoral augments p=0.007. Based on our data, metaphyseal sleeves demonstrate significantly lower revision rates compared to metaphyseal cones. However overall, both demonstrate reliable mid to long-term outcomes.

Modular Augmentation in Varus-Valgus–Constrained Knee Arthroplasty—Do We Need Sleeves to Avoid Femoral Loosening After Excessive Distal Augmentation?

BackgroundIn revision total knee arthroplasty, zonal fixation methods with a combination of augments, press-fit stems, and sleeves are popular. We hypothesized that high distal femoral augmentation with diaphyseal press-fit stems leads to an increased rate of early aseptic loosening and that femoral metaphyseal sleeves improve implant survival. Therefore, we retrospectively investigated implant survival in relation to augment heights and sleeves. MethodsA total of 136 patients with mean clinical follow-up of 50 months (range, 28-85) who underwent modular total knee arthroplasty and revision total knee arthroplasty with semiconstrained implants between January 2012 and July 2018 were retrospectively evaluated. Implant survival with 4, 8, and 12 mm distal femoral augments was compared to no distal augmentation. Subsequently, a subgroup analysis was performed for femoral sleeve implantation. ResultsWe observed an implant survival rate of 97.0%, 87.5%, and 69.2% for 4, 8, and 12 mm distal femoral augmentation, respectively (P = .73; P = .19; P = .008). The implant survival rate with femoral sleeves was 95.8% for the 8 mm augments and 85.7% for the 12 mm augments (P = .42; P = .96). Without femoral sleeves, the implant survival rate was 78.3% with the 8 mm augments and 50.0% with the 12 mm augments (P = .02; P < .001). ConclusionHigher rates of aseptic femoral loosening were identified for distal femoral augmentation of 8 mm or more without metaphyseal sleeve fixation in semiconstrained implants. Thus, in cases with femoral metaphyseal bone damage requiring high distal femoral augmentation, metaphyseal sleeves should be used to avoid early aseptic femoral loosening.

Metaphyseal sleeves in revision total knee arthroplasties: Computational analysis of bone remodeling

BackgroundMetaphyseal sleeves help maintain long term stability and reduce revision rate for aseptic loosening in total knee arthroplasty (TKA) revision. However, their performance regarding bone remodeling is still poorly known for the long term. This study aimed to investigate the impact of metaphyseal sleeves on the bone remodeling of the tibia. MethodsFive finite element models of a female tibia with different implant configurations (regarding stem length and metaphyseal sleeve application) were developed. Loading conditions included joint reaction force, muscle, and tibia-fibula loads from 6 instances of the gait cycle. The bone remodeling model applied was adapted to the subject under analysis by selecting the bone remodeling parameters that best replicated the bone density distribution of the tibia estimated from the CT data. Changes in bone density after TKA were evaluated in 8 regions of interest. ResultsGlobal bone loss ranged from −31.16%, in 115 mm stemmed configurations, to −20.93%, in 75 mm stemmed configurations. Apart from the lateral and posterior regions in the proximal tibia, whose bone loss reduced and increased, respectively, due to the incorporation of a metaphyseal sleeve, changes in bone density were similar with and without a metaphyseal sleeve for each stem length. ConclusionThe results suggest that bone remodeling of the tibia is not critically affected by the incorporation of metaphyseal sleeves. Considering that sleeves are believed to present a favorable clinical outcome in stability and osseointegration, reducing the revision rate for aseptic loosening, their advantages seem to outweigh their disadvantages regarding bone remodeling.