Varus-valgus Constrained Research Articles

The impact of posterior-stabilized vs. constrained polyethylene liners in revision total knee arthroplasty.

Posterior stabilized (PS) and varus valgus constrained (VVC) knee polyethylene liners have been shown to confer excellent long-term functional results following revision total knee arthroplasty (rTKA). The purpose of this study was to compare outcomes of patients who underwent rTKA using either a PS or VVC liner. A retrospective comparative study of 314 rTKA with either PS or VVC liner and a minimum follow-up time of two years was conducted. Patient demographics, complications, readmissions, and re-revision etiology and rates were compared between groups. Kaplan-Meier survivorship analysis was performed to estimate freedom from all-cause revision. Hospital LOS (3.41 ± 2.49 vs. 3.34 ± 1.93days, p = 0.793) and discharge disposition (p = 0.418) did not significantly differ between groups. At a mean follow-up of 3.55 ± 1.60years, the proportion of patients undergoing re-revision did not significantly differ (19.1% vs. 18.7%, p = 0.929). In subgroup analysis of re-revision causes, the VVC cohort had superior survival from re-revision due to instability compared to the PS cohort (97.8% vs. 89.4%, p = 0.003). Freedom from re-revision due to aseptic loosening did not significantly differ between groups (85.2% vs. 78.8%, p = 0.436). Improvements in range of motion (ROM) from preoperative to latest follow-up were similar as well. PS and VVC liners confer similar survivorship, complication rates, and overall knee ROM in rTKA. VVC liners were not associated with increased postoperative aseptic loosening and demonstrated superior freedom from re-revision due to instability. Future studies with longer follow-up are warranted to better determine significant differences in clinical outcomes between the two bearing options. Retrospective Cohort Study.

High survival rate at mid-term follow up of porous tantalum cones for bone defects in revision total knee replacement: A 3–11 years follow up report

BackgroundLarge metaphyseal bone losses are commonly encountered in revision total knee arthroplasty (rTKA). Anderson Orthopaedic Research Institute (AORI) type 2 and 3 defects generally require some metaphyseal fixation or augmentation.This study evaluates the midterm results of Porous Tantalum Trabecular Metal™ (TM) cones in revision TKA addressing severe bone loss. MethodsPatients who underwent revision TKA using metaphyseal cones and a varus–valgus constrained (VVC) implant from January 2010 to January 2018 at our institution were identified from a prospective research database. Pre-operative patient characteristics and operative data were reviewed. Postoperative outcomes were compared with pre-operative values. Primary study aims were to evaluate outcomes, including complications and re-operations, radiographic assessment of cones osteointegration, and survivorship. ResultsA total of 101 knees (101 patients) underwent revision TKA with 139 metaphyseal cones (80 tibial, 59 femoral). AORI defect classification was assessed intraoperatively. All patients were available for a minimum of 2 years of clinical and radiographic follow up. Mean follow up was 7.5 years (range 3–11 years).All patients showed significant improvement of clinical outcomes. Fifteen knees required re-operation and nine required revision of the implants, most commonly for recurrent infection (six of nine revisions) with cones removal.Kaplan–Meier survival analysis show a survival rate of 93.9% at 2 years and a survival rate of 90.2% at 5 and 11 years. ConclusionsThis large series illustrates the utility of porous metaphyseal cones in revision TKA with promising clinical and radiographic results and a high survival rate at mid-term follow up.

Varus-valgus constrained insert with posterior-stabilized femoral components in complex primary total knee arthroplasties.

AimsVarus-valgus constrained (VVC) devices are typically used in revision settings, often with stems to mitigate the risk of aseptic loosening. However, in at least one system, the VVC insert is compatible with the primary posterior-stabilized (PS) femoral component, which may be an option in complex primary situations. We sought to determine the implant survivorship, radiological and clinical outcomes, and complications when this VVC insert was coupled with a PS femur without stems in complex primary total knee arthroplasties (TKAs).MethodsThrough our institution’s total joint registry, we identified 113 primary TKAs (103 patients) performed between 2007 and 2017 in which a VVC insert was coupled with a standard cemented PS femur without stems. Mean age was 68 years (SD 10), mean BMI was 32 kg/m2 (SD 7), and 59 patients (50%) were male. Mean follow-up was four years (2 to 10).ResultsThe five-year survivorship free from aseptic loosening was 100%. The five-year survivorship free from any revision was 99%, with the only revision performed for infection. The five-year survivorship free from reoperation was 93%. The most common reoperation was treatment for infection (n = 4; 4%), followed by manipulation under anaesthesia (MUA; n = 2; 2%). Survivorship free from any complication at five years was 90%, with superficial wound infection as the most frequent (n = 4; 4%). At most recent follow-up, two TKAs had non-progressive radiolucent lines about both the tibial and femoral components. Knee Society Scores improved from 53 preoperatively to 88 at latest follow-up (p < 0.001).ConclusionFor complex primary TKA in occasional situations, coupling a VVC insert with a standard PS femur without stems proved reliable and durable at five years. Longer-term follow-up is required before recommending this technique more broadly.Cite this article: Bone Jt Open 2021;2(11):921–925.

Midterm Survival of a Varus-Valgus Constrained Implant following One-Stage Revision for Periprosthetic Joint Infection: A Single-Center Study.

Revision total knee arthroplasty (TKA) is challenging to perform in patients with periprosthetic joint infection (PJI) due to the difficulty of eradicating the infection and potential for bone and ligamentous deficits. The current study aimed to evaluate the midterm survival of varus-valgus constrained (VVC) implants used in one-stage revision TKA for chronic PJI at our institution. This retrospective analysis included 132 patients with chronic PJI who underwent one-stage revision using a VVC implant. The average follow-up was 51.6 months (range: 24-85 months). Five-year survival analysis was performed to set recurrent infection and mechanical failure as the end point. Hospital for special surgery (HSS) as functional outcomes was evaluated preoperatively and at the latest follow-up. A total of 12 patients (9.1%) underwent retreatment for reinfection (nine patients) and mechanical failure (three patients). The overall 5-year revision-free survival was 82.7%, the infection-free survival was 91.1%, and the mechanical failure-free survival was 98.3%. The preoperative HSS knee score improved from 35.6 points (range: 24.3-47.7 points) preoperatively to 76.8 points (range: 57.2-87.6 points) at the latest follow-up. Complications were identified in 20 patients (15.2%) which included aseptic osteolysis in 4 cases, acceptable flexion instability in 3 cases, arthrofibrosis in 2 patients, hematomas in 2 cases, calf intermuscular venous thrombosis in 6 patients, and femoral stem tip pain in 3 cases. This is the first study to report the outcomes of one-stage revision using VVC implants for knee PJI. Improved functional outcomes and good midterm survival are demonstrated at an average follow-up of 51.6 months.

Outcomes of Stemmed versus Un-Stemmed Varus-Valgus Constrained Components in Primary Total Knee Arthroplasty.

PurposeThe necessity of stemmed components when performing a varus-valgus constrained (VVC) primary total knee arthroplasty (TKA) is unclear. The purpose of this study is to compare the outcomes of primary VVC TKA with and without stems at a minimum of two years.MethodsPatients in our prospectively collected database with primary VVC TKAs were identified. Patient demographics, prosthesis data, time in vivo, characteristics of revision, and radiographs and PROMs were compared between the stemmed and un-stemmed cohorts.ResultsSixty-five patients with 69 primary VVC TKAs were identified; 17 were implanted with stems and 52 without stems. Five of the stemmed TKAs (5/17) required revision at 15.1 years, while only one of the un-stemmed TKA (1/52) required a revision at 21.6 years (p=0.003) for aseptic loosening. Of the 5 stemmed TKAs requiring revision, 3 were for aseptic loosening and 2 were for PPJI. The un-stemmed cohort had a significantly higher final total KSS (p=0.048).ConclusionThere was no increase in aseptic loosening or revision surgery in patients with non-stemmed primary VVC TKA compared to those with stemmed VVC TKA at mid-term follow-up. Utilizing non-stemmed TKA with VVC in appropriate cases is safe and may reduce cost, shorten operative time, and preserve bone-stock.

Varus-Valgus Constrained Implants in Revision Total Knee Arthroplasty: Mean Clinical Follow-Up of Six Years

BackgroundThere is scant literature evaluating varus-valgus constrained (VVC) prostheses in contemporary revision total knee arthroplasty (TKA). Therefore, we aimed to evaluate the durability of VVC revision TKA with selective use of cones. MethodsA retrospective review of 194 revision TKAs with VVC was performed from August 2005 through February 2018 at a single institution. The final cohort consisted of 168 TKAs with a mean follow-up of 6 years. Stems were used in all but 1 TKA, tibial cones in 48%, and femoral cones in 19%. Anderson Orthopaedic Research Institute classification in femurs was 1 in 57, 2A in 33, 2B in 62, 3 in 16, and in tibias, 1 in 42, 2A in 29, 2B in 81, and 3 in 16. ResultsSurvival analysis showed that 93% were free of revision for aseptic component loosening, 76% were free of revision for any reason, and 74% were free of reoperation at 6 years. Anderson Orthopaedic Research Institute 3 femur or tibia, age <65 years, and progressive radiographic changes were associated with an increased risk of revision for aseptic loosening (P < .05). Progressive radiographic changes were seen in 19% of femoral and 16% of tibial constructs. The most common reason for re-revision was periprosthetic joint infection (65%). ConclusionVVC revision TKA with selective use of cones provided a reasonable outcome as 93% were free of revision for aseptic loosening at 6 years. However, given the rate of patients with progressive radiographic changes and survivorship free of reoperation of 74% at 6 years, long-term follow-up will help assess the durability of these constructs.

L’épaisseur de la surface articulaire d’une arthroplastie unicompartimentale du genou permet-t-elle de prédire l’importance de la perte osseuse tibiale en cas de révision au profit d’une prothèse tricompartmentale ?

BackgroundBone defects during revision procedures for failed UKA represent a challenge even for the most experienced surgeons; therefore, an accurate preoperative planning remains essential to prevent dramatic scenarios in the surgical theatre. HypothesisOur hypothesis is that bearing thickness used in original UKA represents a reliable predictor of severe tibial bone loss, requiring a metallic augment or constrained implant, during revision to TKA. Patients and methodsForty-two patients who underwent a total knee arthroplasty from failed UKA were identified from our institutional database and evaluated clinically using the Knee Society Score (KSS). A multivariate logistic regression analysis was performed using the presence of tibial augments or the need of varus-valgus constrained (VVC) prosthesis as depend variables, and patients’ gender, age at revision procedure, side (medial or lateral), UKA tibial tray (all-polyethylene or metal back), bearing thickness (composite thicknesses of the metal-backed tray and insert or all-polyethylene tibial component≤8mm or more than 8mm) and cause of failed UKA as independent variables. ResultsA posterior-stabilized prosthesis was used in 27 cases (64.3%). An augment was necessary in 12 patients (28.6%). Initial bearing thickness greater than 8mm was associated with greater likelihood of a VVC implant (OR=11.78, 95% CI: 1.6583 to 83.6484, p=0.0137) and a tibial augment (OR=9.59, 95% CI: 1.327 to 69.395, p=0.0251). Tibial tray design, patients’ gender or age during revision surgery, side or cause of failure were not associated to increased risk of augmentation or constrained implants. DiscussionSurgeons should be aware of the particular challenges that the conversion of a UKA to a TKA presents and be prepared to address them intraoperatively, with particular care to proper bone loss manage. Satisfying results can be achieved at mid-to-long-term follow-up, if these procedures are planned accurately, and a precise analysis of failed UKA components, in particular bearing thickness, represents a helpful support in this context. Level of evidenceIV, retrospective case series.

Bearing thickness of unicompartmental knee arthroplasty is a reliable predictor of tibial bone loss during revision to total knee arthroplasty

BackgroundBone defects during revision procedures for failed UKA represent a challenge even for the most experienced surgeons; therefore, an accurate preoperative planning remains essential to prevent dramatic scenarios in the surgical theatre. HypothesisOur hypothesis is that bearing thickness used in original UKA represents a reliable predictor of severe tibial bone loss, requiring a metallic augment or constrained implant, during revision to TKA. Patients and methodsForty-two patients who underwent a total knee arthroplasty from failed UKA were identified from our institutional database and evaluated clinically using the Knee Society Score (KSS). A multivariate logistic regression analysis was performed using the presence of tibial augments or the need of varus-valgus constrained (VVC) prosthesis as depend variables, and patients’ gender, age at revision procedure, side (medial or lateral), UKA tibial tray (all-polyethylene or metal back), bearing thickness (composite thicknesses of the metal-backed tray and insert or all-polyethylene tibial component ≤8mm or more than 8mm) and cause of failed UKA as independent variables. ResultsA posterior-stabilized prosthesis was used in 27 cases (64.3%). An augment was necessary in 12 patients (28.6%). Initial bearing thickness greater than 8mm was associated with greater likelihood of a VVC implant (OR=11.78, 95% CI, 1.6583 to 83.6484, p=0.0137) and a tibial augment (OR=9.59, 95% CI, 1.327 to 69.395, p=0.0251). Tibial tray design, patients’ gender or age during revision surgery, side or cause of failure were not associated to increased risk of augmentation or constrained implants. DiscussionSurgeons should be aware of the particular challenges that the conversion of a UKA to a TKA presents and be prepared to address them intraoperatively, with particular care to proper bone loss manage. Satisfying results can be achieved at mid-to-long term follow-up, if these procedures are planned accurately, and a precise analysis of failed UKA components, in particular bearing thickness, represents a helpful support in this context. Level of evidenceIV, retrospective case series.

Similar outcomes with usage of varus valgus constrained and a rotating hinge knee: A review of 108 cases

ObjectiveConstraint is defined as the effect of elements knee implant designs that provide the stability needed in the presence of a deficient soft tissue envelope. The prosthesis with the minimal acceptable constraint generates maximal functional outcome is the general dictum. Varus valgus constrained (VVC) and rotating hinge knees(RHK) are implants which comprise the constraint group with later having higher constraint. However there are no clearcut guidelines of usage of each of the above implant group and literature is sparse in comparison of outcomes of the above 2 groups. This study was done with aim to better delineate indications and compare outcomes of the VVC and RHK implants. MethodsWe evaluated 56 varus valgus constrained and 52 rotating hinge total knee arthroplasties. The indication of usage and basic demographic data was collected. Clinical and functional outcomes were calculated and compared between the implant groups. ResultThe mean final range of motion (ROM) was 104.58° in RHK group and 108.75 in the VVC group. The final mean Oxford knee score (OKS) was 31.23 in the RHK group and 32 .44 in the VVC group. The final mean Knee society score (KSS) was 81.69 in RHK group and 83.79 in the VVC group. There was no statistically significant difference in the 2 groups when final mean ROM, OKS and KSS were compared. Thus the two implant groups gave similar clinical and functional outcomes. The number of revision were similar in RHK (4/52) and VVC (4/56) group. ConclusionThus similar outcomes were reported in our study when both implant groups were compared. We recommend usage of RHK in revision of infected Total knee arthroplasty, in cases with any amount of flexion extension mismatch and in cases where there is doubt regarding partial or full incompetence of collaterals. The use of VVC should be restricted to Osteoarthritis (OA) with gross deformities. However long term randomised clinical trial is needed to better define longevity and complications in the 2 implant groups.

Difficult primary total knee arthroplasty requiring a varus-valgus constrained implant is at higher risk of periprosthetic infection.

The goal of this study was to compare the risk of periprosthetic infection of a consecutive cohort of primary varus-valgus constrained (VVC) total knee arthroplasties (TKAs), with a matched 1:1 cohort of primary posterior-stabilized (PS) TKAs. 74 primary VVC TKAs performed in 66 patients were identified and matched 1:1 with a cohort of 74 primary PS TKAs performed in 73 patients. At last follow up, patients were clinically evaluated using the Knee Society Score (KSS). Kaplan-Meier survival curves were generated to analyze survivorship using as endpoints revision for any reason, revision for periprosthetic infection and revision for mechanical failure after excluding periprosthetic infection. A multivariate logistic regression analysis was constructed to determine whether revision surgery for periprosthetic infection was influenced by patients' gender, age, surgical time and reasons for TKA (primary vs secondary osteoarthritis). Demographic data were not significantly different between the two groups as regard patients' age, gender, body mass index, Charlson Comorbidity Index, reasons for replacement, and length of follow-up. Surgical time was greater in the VVC group (95.7 ± 22.5min vs 88.6 ± 17.1min, respectively, p = 0.032). Postoperative KSS, range of motion and radiographic data did not differ significantly between the two groups. Overall revision rate and revision rate for mechanical failure after 5years of follow-up was not statistically different between the two groups. Considering only the revision rate due to periprosthetic infection, the risk was higher in patients with primary VVC implants (p = 0.013). The surgical time was the only factor that significantly affected the risk of revision for periprosthetic infection (OR 1.0636, CI 95% 1.0209-1.1081, p = 0.0032), whereas patients' gender, age and reason for TKA had no influence. Patients and surgeons should be aware of the higher risk of periprosthetic knee infection using a VVC prosthesis. However, the present study supports the use of VVC implants in cases of difficult knee replacements, since comparable clinical outcomes and overall revision rate was found after at least 5years of follow up. Retrospective cohort study, Level III.

Does the severity or cause of preoperative stiffness affect the clinical results and range of motion after total knee arthroplasty?

The purpose of this study was to assess the overall clinical results and range of motion (ROM) after total knee arthroplasty (TKA) in patients with preoperative stiffness. We also aimed to determine whether the severity or cause of the stiffness can affect the clinical outcome after surgery. This retrospective study included 122 knees (117 patients) with follow-up of more than 2 years (mean age, 64.3 years). TKA was performed using posterior-stabilized, varus-valgus constrained (VVC), and hinged prostheses. To determine the effect of the severity of stiffness on the clinical outcome, the subjects were divided into two groups: the severe group (preoperative ROM ≤ 50°; 18 knees) and the moderate group (preoperative ROM, 50°–90°; 104 knees). Then, clinical results and ROM were compared according to the severity or cause of preoperative stiffness. After surgery, preoperative ROM (mean, 78°; range, 25°- 90°) was improved (mean, 107°; range, 70°- 130°). The severe group more frequently used the VVC or hinged prostheses (72% vs. 18%). Furthermore, the severe group had worse knee and function scores as well as more complications (33% vs. 13%), even though the severe group had a greater ROM increment (47° vs. 27°) after surgery. Patients with osteoarthritis and rheumatoid arthritis showed better ROM and clinical results compared to patients with infectious or traumatic arthritis. Although TKA in stiff knees can be successful, the results are inferior in knees with severe stiffness and knees with infectious or traumatic arthritis.

Metaphyseal sleeves as the primary implant for the management of bone defects in total knee arthroplasty after post-traumatic knee arthritis

BackgroundImplantation of a prosthesis after post-traumatic knee arthritis poses challenges derived from the bone defects and soft tissue damage. The objective of this study was to evaluate the clinical and radiological results of the use of metaphyseal sleeves in primary total knee arthroplasty surgery after post-traumatic arthritis. MethodsClinical and radiological results of 25 patients undergoing surgery for post-traumatic knee arthritis were prospectively evaluated. A semi-constrained, mobile platform prosthesis with metaphyseal sleeves was implanted. American Knee Society scales, Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Short Form 12 Health Survey were used. Patients were evaluated at the baseline and at postoperative months three, 12, and annually until final follow-up. ResultsThe mean follow-up was 79 months with a maximum of 10 years. Mean Knee Society Score (KSS) increased from 29 to 78, and functional KSS from 42 to 81.The average WOMAC pain index changed from 12 to three; average WOMAC stiffness improved from four to one, and WOMAC function score improved from 44 to 16.The mean physical SF12 varied from 30 to 46, while mental SF-12 varied from 45 to 55.Radiological osseointegration of the implants was considered optimal in all cases, with a survival of 100%. ConclusionsMetaphyseal sleeves in combination with varus–valgus constrained (VVC) components and a rotating platform, have shown good clinical and radiological results in patients with post-traumatic knee arthritis and constitute a reliable alternative for treatment of this disease when the epiphyseal zone is deteriorated and has bone defects.

A case of bilateral revision total knee arthroplasty using distal femoral allograft\u2013prosthesis composite and femoral head allografting at the tibial site with a varus-valgus constrained prosthesis: ten-year follow up

BackgroundWe report the successful use of allograft–prosthesis composite (APC) and structural femoral head allografting in the bilateral reconstruction of large femoral and tibial uncontained defects during revision total knee arthroplasty (RTKA).Case presentationA 67-year-old female with degenerative arthritis underwent bilateral total knee arthroplasty (TKA) using the Press Fit Condylar (PFC) modular knee system at our clinic in March, 1996. At 8 years postoperatively, the patient presented with painful, bilateral varus knees, with swelling, limited passive range of motion (ROM), and severe instability. We treated to reconstruct both knee using a femoral head allograft at the tibial site, a structural distal femoral allograft at the femoral site, and a varus-valgus constrained (VVC) prosthesis with cement. At the 10-year follow up, we found no infection, graft failure, loosening of implants, in spite of using massive bilateral structural femoral head allografts in RTKA.ConclusionThe use of APC enabled a stable and durable reconstruction in this uncommon presentation with large femoral bone deficiencies encountered during a RTKA.

Varus-valgus constrained implants in total knee arthroplasty: indications and technique.

Total knee arthroplasty is a successful operation that significantly improves patient's quality of life. However, studies demonstrated as only 82% to 89% of patients are satisfied with their surgery, being the other disappointed with regard to their expectations. Two to 5.7% of total knee arthroplasties (TKAs) require revision within 5 years. Both complex primary cases and revision TKA often necessitate for a higher degree of constrain than cruciate retaining or postero-stabilized implant design. In the 1970s varus-valgus constrained (VVC) or semi-constrained implants have been developed by Insall and associates from the PS design, which provide varus-valgus stability preserving a fair amount of host bone. VVC TKAs allows for a small amount of movement in the coronal, antero-posterior and axial planes. In this paper, the authors give an overview of the indications, outcomes and technique for varus-valgus constrained implants, both in the setting of primary and revision knee arthroplasty.

The Varus-Valgus Constrained Knee Implant: Survivorship and Outcomes.

The purpose of this study was to estimate the survivorship of the varus-valgus constrained (VVC) knee implants in primary, aseptic, and septic revision total knee arthroplasty (TKA); determine functional outcomes; main modes of failure; and variables associated with increased mechanical failures. In this study, 685 consecutive cases of primary (n = 247), aseptic (n = 315), and septic revision (n = 123) TKAs with VVC implants were performed between 1999 and 2008; 533 knees (78%) had a mean follow-up of 8.2 years (range, 2-15.1). Kaplan-Meier method was used to evaluate implant survival with mechanical failure as the end point. Clinical outcomes were measured with a modified Knee Society Score (mKSS) and modified Knee Function Score (mKFS) and modes of failure were determined. Cox proportional hazards models were performed to assess for factors associated with implant failure. Ten-year survival was 88.5% (95% confidence interval [CI]: 83.9-93.5%) for primary TKAs, 75.8% (95% CI: 70.4-81.7%) for aseptic, and 54.6% (95% CI: 43.7-68.2%) for septic revisions. Improvement in pre- to postoperative mKSS and mKFS were significant in all three groups (p < 0.05). The most common mode of failure overall was infection. Mechanical modes of failures included periprosthetic fracture (45%) for primary TKA and soft tissue instability (19%) for aseptic revisions. A longer period since the last surgery in affected knee was associated with lower mechanical failures (hazards ratio of 0.55 [95% CI: 0.31-0.95], p = 0.03). VVC implant showed reliable survivorship at 10 years although careful patient selection is warranted due to the risk of infection. The main mechanical modes of failure were instability and periprosthetic fracture.

The Fate of Allogeneic Femoral Head Bone Grafts Using Varus–Valgus Constrained Total Knee Arthroplasty in Neuropathic Joints

BackgroundThis study was conducted to assess the clinical and radiological results of total knee arthroplasty (TKA) with an allogeneic bone graft using varus–valgus constrained (VVC) prostheses in knees with severe bone defects and unstable neuropathy. MethodsThis study included 20 knees of 16 patients who underwent TKA between August 2001 and January 2006 due to unstable knees with severe bone destruction resulting from neuropathic arthritis. At the time of surgery, the mean age of the patients was 56 years. The mean length of the follow-up period was 10.7 years. A VVC condylar prosthesis was used with an allogeneic femoral head graft to reconstruct large bony defects. Clinical results were evaluated using the Hospital for Special Surgery, Knee Society function, and Western Ontario and McMaster Universities Osteoarthritis scores. Three-dimensional computed tomography was used to evaluate the radiological parameters, which included the tibiofemoral angle, loosening or osteolysis of components, and incorporation of the bone graft. ResultsThe preoperative mean Hospital for Special Surgery, Knee Society function, and Western Ontario and McMaster Universities Osteoarthritis scores were 40.5, 43.2, and 78.3, respectively, and these scores improved to 86.0, 64.6, and 33.8, respectively at the final follow-up. The mean postoperative alignment was 6.1° of valgus angulation. One knee had instability, another knee had partial bony absorption, which was confirmed using 3-dimensional computed tomography, and the other 18 cases (90%) had satisfactory results. No cases experienced radiolucency, fracture, or infection. ConclusionsTKA with an allogeneic bone graft using a VVC prosthesis provides a viable option for the treatment of severe bone defects with soft-tissue insufficiency in neuropathic knee arthropathy.