[The bicompartmental knee joint prosthesis Journey Deuce: failure analysis and optimization strategies]

Journey-Deuce bicompartmental knee arthroplasty with the addition of computer navigation achieves good clinical outcomes and implant survival at 10 years

PURPOSE

To report 10-year outcomes and survivorship in patients undergoing bicompartmental knee arthroplasty (BCKA) using the Journey-Deuce prosthesis in a consecutive prospective case series.

METHODS

Between November 2006 and November 2009, 41 patients with a mean age of 69.6 years (range 51-86) underwent 51 bicompartmental knee arthroplasties with the Journey-Deuce knee prosthesis. All patients presented with symptomatic medial and patellofemoral compartment osteoarthritis, with intact cruciate ligaments and a preserved lateral compartment on plain radiographs and Magnetic Resonance Imaging. Clinical assessment was undertaken pre-surgery and at 1, 2, 5 and 10 years post-surgery using the Oxford Knee Score (OKS), EuroQol Group 5-Dimension self-reported questionnaire (EQ-5D) and maximal active range of motion (ROM).

RESULTS

30 patients (37 knees) were followed-up at a mean time of 11.4 years (SD 1.1; range 10.5-14.0). Eight patients (ten knees) were deceased and three could not be contacted at final review. No major component revision was performed. Pre-operative OKS 25.4 (SD 5.2; range 15-40), knee flexion 116.4° (SD 10.3°; range 100°-140°) and EQ-5D 70.5 (SD 19.9; range 25-95). 10-year OKS 43.5 (SD 4.1; range 32-48), knee flexion 127.3° (SD 11.1°; range 105°-144°) and EQ-5D 77.4 (SD 9.3; range 60-100). The OKS (p < 0.0001), EQ-5D (p = 0.024) and active knee flexion ROM (p < 0.0001) all significantly improved from pre-surgery to 1-year post-surgery, with no further significant changes in these scores between any post-operative time period up until 10 years. 32% (7/22) of tibial and 45% (10/22) of femoral components showed progressive radiolucencies between 2 and 5-year and 10-year follow-up.

CONCLUSIONS

This is the largest cohort of patients having undergone BCKA (with the Journey-Deuce prosthesis) with longest follow-up described in the literature. At 10 years, patients presented with significantly improved clinical outcomes, comparable to other surgical arthroplasty options. No major component revision was performed. Progressive radiolucencies were noted in 32% of tibial and 45% of femoral components without corresponding clinical signs of loosening.

LEVEL OF EVIDENCE

Level III.

Bicompartmental, medial and patellofemoral knee replacement might be able to maintain unloaded knee kinematics

INTRODUCTION

Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are standard procedures for treating knee joint arthritis. Neither UKA nor TKA seems to be optimally suited for patients with bicompartmental osteoarthritis that affects only the medial and patellofemoral compartments. A bicompartmental knee arthroplasty (BKA) was designed for this patient group. This study aimed to compare the effectiveness of a BKA and TKA in restoring the kinematics of the knee joint.

MATERIALS AND METHODS

In this in vitro study, three types of knee arthroplasties (BKA, posterior cruciate ligament-retaining, and posterior cruciate ligament-resecting TKA) were biomechanically tested in six freshly frozen human cadaveric specimens. Complete three-dimensional kinematics was analyzed for each knee arthroplasty during both passive and loaded conditions in a validated knee kinematics rig. Infrared motion capture cameras and retroreflective markers were used for recording data.

RESULTS

No significant differences could be found between the three types of arthroplasties. However, similar kinematic changes between BKA and a native knee joint were documented under passive conditions. However, in a weight-bearing mode, a significant decrease in femoral rotation during the range of motion was found in arthroplasties compared to the native knee, probably caused by contraction of the quadriceps femoris muscle, which leads to a decrease in the anterior translation of the tibia.

CONCLUSIONS

Kinematics similar to that of the natural knee can be achieved by BKA under passive conditions. However, no functional advantage of BKA over TKA was detected, which suggests that natural knee kinematics cannot be fully imitated by an arthroplasty yet. Further prospective studies are required to determine the anatomic and design factors that might affect the physiologic kinematics.

Relevant changes of leg alignment after customised individually made bicompartmental knee arthroplasty due to overstuffing

PURPOSE

The purpose of this study is to analyse the change in knee alignment after customised individually made (CIM) bicompartmental knee arthroplasty (BKA) and the subsequent consequences for patellar tracking.

METHODS

Medical records of 23 patients who received 26 CIM BKA (ConforMIS iDuo G2) at our clinic between November 2015 and July 2018 were reviewed. The objective part of the Knee Society Score (KSS), the hip-knee-ankle angle (HKA), the tibial mechanical angle (TMA) and femoral mechanical angle (FMA) were recorded preoperative and four months postoperative. Leg alignment was classified as neutral (HKA = 180° ± 3°), varus (HKA < 177°) or valgus (HKA > 183°). Furthermore, patellar tracking was determined on skyline view radiographs and adverse events were recorded. Implant survival rate was determined with the Kaplan-Meier method. Patient-reported outcome measures (PROMs) were pain, satisfaction, overall improvement and if the patient would undergo the surgery again.

RESULTS

The mean KSS improved from 61 points preoperative [standard deviation (SD) 14] to 90 points postoperative (SD 7, p < 0.001). The mean change for HKA was 6.3° (SD 3.5), for TMA 1.5° (SD 1.2) and for FMA 3.8° (SD 2.3). Postoperative leg alignment was neutral in 13 CIM BKA (50%), varus in two (8%) and valgus in 11 (42%) and patella tracking was central in 19 CIM BKA (73%) and lateral in seven (27%), respectively. Adverse events occurred in five CIM BKA: three patients required a patella resurfacing and one patient with bilateral CIM BKA needed a revision to a total knee arthroplasty. Implant survival rate was 92.3% at a follow-up of 3.2 years (SD 0.8). PROMs for CIM BKA without revision surgery were available at a mean follow-up of 3.2 years (SD 0.8). Mean pain with level walking decreased to 0.8 points (SD 1.4, p < 0.001) and mean pain with stairs or inclines to 1.6 points (SD 1.3, p < 0.001). Patient satisfaction was very satisfied or satisfied (78%), neutral (17%) or unsatisfied (4%). Overall improvement was much better or considerably better for 91% of all patients; 87% would undergo the surgery again.

CONCLUSION

A relevant change of the leg axis away from the treated femorotibial compartment due to overstuffing was observed. Although, neutral leg alignment was not restored in every case, clinical and patient-reported outcomes improved significantly. Further studies with long-term clinical and patient-reported outcomes are required to evaluate whether patients with bicompartmental knee osteoarthritis benefit from CIM BKA.

LEVEL OF EVIDENCE

IV, case series.

Contemporary knee arthroplasty: one fits all or time for diversity?

INTRODUCTION

Total knee arthroplasty (TKA) has historically been the preferred solution for any type of knee osteoarthritis, independently of the number of compartments involved. In these days of patient-specific medicine, mono-compartmental disease could also be approached with a more individualized treatment, such as partial knee arthroplasty (PKA). Off-the-shelf (OTS) implants are often the compromise of averages and means of a limited series of anatomical parameters retrieved from patients and the pressure of cost control by limited inventory. Personalized medicine requires respect and interest for the individual shape and alignment of each patient.

MATERIALS AND METHODS

A Pubmed and Google Scholar search were performed with the following terms: "patient-specific knee" and "arthroplasty" and "custom implant" and "total knee replacement" and "partial knee replacement" and "patellofemoral knee replacement" and "bicompartmental knee replacement". The full text of 90 articles was used to write this narrative review.

RESULTS

Unicondylar, patellofemoral and bicompartmental knee arthroplasty are successful treatment options, which can be considered over TKA for their bone and ligament sparing character and the superior functional outcome that can be obtained with resurfacing procedures. For TKA, where compromises dominate our choices, especially in patients with individual variations of their personal anatomy outside of the standard, a customized implant could be a preferable solution.

CONCLUSION

TKA might not be the only solution for every patient with knee osteoarthritis, if personalized medicine wants to be offered. Patient-specific mono-compartmental resurfacing solutions, such as partial knee arthroplasty, can be part of the treatment options proposed by the expert surgeon. Customized implants and personalized alignment options have the potential to further improve clinical outcome by identifying the individual morphotype and respecting the diversity of the surgical population.

Unicompartmental vs. segmental bicompartmental vs. total knee replacement: comparison of clinical outcomes

Purpose

Combined medial tibiofemoral and symptomatic patellofemoral osteoarthritis is not amenable to unicompartmental knee replacement (UKR). Total knee replacement (TKR) is an invasive option in younger adults with high functional demands. The aim of this study was to compare the clinical outcome of patients who have undergone UKR, bicompartmental knee replacement (BKR) and TKR up to 2 years post-operatively.

Materials and methods

This prospective study comprised 133 subjects including 30 patients in the medial UKR group, 53 patients in the BKR group (combined medial UKR with patellofemoral joint replacement) and 50 patients in the TKR group. All subjects were evaluated using the Oxford Knee Score (OKS) and the Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC). Patients in each group were assessed using both scoring systems pre-operatively and 6 months, 1 year and 2 years post-operatively.

Results

Significant improvement of OKS was found at 6 months compared to baseline for UKR (22.7 to 38.1, p = 0.046), BKR (22.6 to 36.8, p < 0.001) and TKR (16.6 to 34.5, p < 0.001). Significant improvement was also found for the WOMAC sub-scores for all three groups during this time period. After 6 months, there was no further statistically significant improvement in either outcome score in any of the groups up to the 2-year follow-up results. There was no significant difference in either outcome score post-operatively between the three groups.

Conclusion

The magnitude of clinical improvement following knee replacement is greatest at 6 months; thereafter, only modest improvements continue to occur. This study also found no significant differences of outcomes at 2 years after surgery among UKR, BKR and TKR. BKR is a good alternative option for combined symptomatic medial and patellofemoral arthritis of the knee.

Customised bi-compartmental knee arthroplasty shows encouraging 3-year results: findings of a prospective, multicenter study

PURPOSE

The purpose of this study was to assess the clinical and patient-reported outcomes of a customised, individually made (CIM) bi-compartmental knee arthroplasty (BKA).

METHODS

A prospectively recruited cohort of 79 patients was implanted with a CIM-BKA (patello-femoral plus either medial or lateral tibio-femoral, iDuo G2 system, Conformis, Billerica MA) at eight centres in the US and Germany. Patients were assessed for the 2011 KSS, KOOS, and ROM pre-operatively and at 2 weeks, 6 weeks, 12 weeks, 1 year, and 2 years post-operatively.

RESULTS

The objective KSS score significantly improved from 69 at the pre-operative visit, to 94 at the 2-year post-operative time-point. Similar improvements were observed for the KSS function and satisfaction domains. Significant improvements from pre-operative levels were observed across all five domains of the KOOS. Two patients have undergone surgery to revise their CIM-BKA implant to total knees, resulting in a survivorship rate of 97.5% at an average follow-up of 2.6 years.

CONCLUSIONS

CIM-BKA compares favourably to published scores as well as revision rates for previously available monolithic OTS-BKA implants. CIM-BKA implants provide surgeons with a viable and patient-specific monolithic implant solution as an option for patients presenting with bi-compartmental disease, who might, otherwise, be treated by performing uni-condylar + patello-femoral joint or bicruciate sparing TKA surgeries. Longer follow-up and higher numbers have to be awaited for further validation of these encouraging early results.

LEVEL OF EVIDENCE

3b (individual case-controlled study).

Evaluation of the application value of a three-dimensional digital model of the knee in clinical practice

Objective

To compare the knee shape and bone parameters between knee prosthesis products from overseas companies and a Chinese patient’s knee, and to apply the anatomical basis for Chinese knee prosthesis design.

Methods

Three-dimensional digital models were built, including prosthesis products for a normal adult. The relevant anatomy index was measured, and physical parameter, radiographic, geometric, knee kinematic, and distal geometry data were collected on the femur and tibia.

Results

The width of the femoral condyle (WFC), width of the medial femoral condyle (WMFC), width of the lateral femoral condyle (WLFC), depth of the intercondylar fossa (DICF), sagittal length of the medial femoral condyle (SLMFC), sagittal length of the lateral femoral condyle (SLLFC), angle of the medial femoral condyle (AMFC), and angle of the lateral femoral condyle (ALFC) in the femur and the transverse diameter (ML) and anteroposterior diameter (AP) of the tibial bone were measured. These parameters were significantly lower in the normal group compared with the prosthesis product model group.

Conclusion

When using an imported knee prosthesis, the osteotomy angle may not fit perfectly. Use of an imported prosthesis may be an important factor in the increasing failure of knee arthroplasty in China.

Adoption of New Medical Technologies: The Case of Customized Individually Made Knee Implants

OBJECTIVES

To investigate the impact of insurance coverage on the adoption of customized individually made (CIM) knee implants and to compare patient outcomes and cost effectiveness of off-the-shelf and CIM implants.

METHODS

A system dynamics simulation model was developed to study adoption dynamics of CIM and meet the research objectives. The model reproduced the historical data on primary and revision knee replacement implants obtained from the literature and the Nationwide Inpatient Sample. Then the dynamics of adoption of CIM implants were simulated from 2018 to 2026. The rate of 90-day readmission, 3-year revision surgery, recovery period, time savings in operating rooms, and the associated cost within 3 years of primary knee replacement implants were used as performance metrics.

RESULTS

The simulation results indicate that by 2026, an adoption rate of 90% for CIM implants can reduce the number of readmissions and revision surgeries by 62% and 39%, respectively, and can save hospitals and surgeons 6% on procedure time and cut down cumulative healthcare costs by approximately $38 billion.

CONCLUSIONS

CIM implants have the potential to deliver high-quality care while decreasing overall healthcare costs, but their adoption requires the expansion of current insurance coverage. This work presents the first systematic study to understand the dynamics of adoption of CIM knee implants and instrumentation. More broadly, the current modeling approach and systems thinking perspective could be used to consider the adoption of any emerging customized therapies for personalized medicine.

Evaluation of implant fit and frontal plane alignment after bi-compartmental knee arthroplasty using patient-specific instruments and implants

INTRODUCTION

The goals of successful bi-compartmental knee arthroplasty are to achieve correct fit and positioning of the implant, while appropriately correcting the mechanical alignment of the leg after surgery. As these requirements are not always reliably fulfilled using off-the-shelf implant systems, newer approaches for bi-compartmental resurfacing have been explored.

MATERIAL AND METHODS

In this article we report the radiographic results of 30 patients with anteromedial osteoarthritis (OA) who were treated with a novel patient-specific fixed-bearing bi-compartmental knee resurfacing system using custom-made implants and instruments. Utilizing standardized pre- and postoperative radiographic analyses (based on anterior-posterior and lateral, anterior-posterior weight-bearing full-length radiographs, patella skyline views and preoperative computed tomography (CT) scanning) implant fit and positioning as well as correction of the mechanical axis (hip-knee-ankle angle, HKA) were determined.

RESULTS

On average, HKA was corrected from 173.4 ±3.47° preoperatively to 179.4 ±2.85° postoperatively. The coronal femoro-tibial angle was corrected on average 5.61°. The preoperative tibial slope measured on lateral views was 6.38 ±2.4°, while the average slope in the CT-based planning protocol (iView) was 6.14 ±2.40°. Postoperative lateral tibial slope was determined to be 5.77 ±1.97°. The thickness of the posterior femoral cuts was measured intraoperatively and, in all cases, corresponded well to the targeted thickness of the cuts provided by the iView. The joint line was preserved in all cases and the average Insall-Salvati index was 1.078 ±0.11 pre- and 1.072 ±0.11 postoperatively. The fit of the implant components measured by over- or underhang was excellent throughout (< 1.01 mm).

CONCLUSIONS

Custom-made bicompartmental knee arthroplasty can ensure optimized fitting and positioning of the implant with restoration of the leg axis. These implants could be considered as an alternative primary solution for knee surgeons treating bi-compartmental disease.

Bicompartmental individualized knee replacement : Use of patient-specific implants and instruments (iDuo™)

OBJECTIVE

Bicompartmental knee replacement in patients with combined osteoarthritis (OA) of the medial or lateral and patellofemoral compartment. Patient-specific instruments and implants (ConforMIS iDuo™) with a planning protocol for optimal implant fit.

INDICATIONS

Bicompartmental OA of the knee (Kellgren & Lawrence stage IV) affecting both the medial or lateral and patellofemoral compartment after unsuccessful conservative or joint-preserving surgery.

CONTRAINDICATIONS

Tricompartmental OA, knee ligament instabilities, knee deformities >15° (varus, valgus, extension deficit). Relative contraindication: body mass index >40; prior unicompartmental knee replacement or osteotomies.

SURGICAL TECHNIQUE

Midline or parapatellar medial skin incision, medial arthrotomy; identify mechanical contact zone of the intact femoral condyle (linea terminalis); remove remaining cartilage and all osteophytes that may interfere with the correct placement of the individually designed instruments. Balance knee in extension with patient-specific balancing chips. Resection of proximal tibia with an individual cutting block; confirm axial alignment using an extramedullary alignment guide, balance flexion gap using spacer blocks in 90° flexion. Final femur preparation with resection of the anterior trochlea. After balancing and identification of insert heights, final tibial preparation is performed. Implant is cemented in 45° of knee flexion. Remove excess cement and final irrigation, followed by closure.

POSTOPERATIVE MANAGEMENT

Sterile wound dressing; compressive bandage. No limitation of active/passive range of motion (ROM). Partial weight bearing the first 2 weeks, then transition to full weight bearing. Follow-up directly after surgery, at 12 and 52 weeks, then every 1-2 years.

RESULTS

In all, 44 patients with bicompartmental OA of the medial and patellofemoral compartment were treated. Mean age 59 years. Minimum follow-up 12 months. Implant converted to TKA due to tibial loosening (1 patient); patella resurfacing (3 patients). No further revisions or complications. Radiographic analyses demonstrated ideal fit of the implant with less than 2 mm subsidence or overhang. KSS pain scores improved from preoperatively 5.7 to 1.7 postoperatively with level walking, and from 7.3 preoperatively to 2.8 postoperatively with climbing stairs or inclines. The WOMAC score improved from preoperatively 43 to 79 postoperatively.

Navigated "small implants" in knee reconstruction

PURPOSE

At the beginning of this century, unprecedented interest in the concept of using less invasive approaches for the treatment of knee degenerative diseases was ignited. Initial interest in this approach was about navigated and non-navigated knee reconstruction using small implants and conventional total knee arthroplasty.

METHODS

To this end, a review of the published literature relating to less invasive compartmental arthroplasty of the knee using computer-based alignment techniques and on soft tissue-dedicated small implants is presented. The authors present and compare their personal results using these techniques with those reported in the current literature. These involved the use of a shorter incision and an emphasis sparing. However, nowadays most surgeons look at compartmental knee resurfacing with the use of small implants as the new customized approach for younger and higher-demand patients. The aim of this paper is to stimulate further debate.

RESULTS

Since the beginning of 2000, computer-assisted surgery has been applied to total knee arthroplasty (TKA) and later to compartmental knee arthroplasty. Recent studies in the literature have reported better implant survivorship for younger patients using navigation in TKA at longer-term follow-up. Only one published report was identified showing superior clinical outcomes at short-term follow-up using computer-assisted technology compared with conventional alignment techniques in small implant surgery. No studies were found in the literature that demonstrated similar clinical advantages with navigated small implants at long-term follow-up. Two published meta-analyses were identified reporting better implant and limb alignment and no increase in complications using a navigated unicompartmental knee arthroplasty. However, neither meta-analysis showed superior clinical outcomes or survivorship with the navigated techniques.

CONCLUSION

In conclusion, we can assert that replacing just the damaged compartment and preserving the normal biomechanics will require not only new implant designs but also new technologies allowing the surgeon to make extremely precise adjustments to implant alignment and providing continuous feedback during surgery.

LEVEL OF EVIDENCE

IV.

Early failure with the Journey-Deuce bicompartmental knee arthroplasty

The aim of this study was to evaluate the early functional outcome and survivorship of a bicompartmental knee arthroplasty implant (Journey-Deuce) in a cohort of patients with combined medial and patellofemoral degenerative osteoarthritis. Fifteen patients with a mean age of 57 years were followed up prospectively and evaluated with clinical examination, Oxford knee score and radiology imaging. Poor pain scores, concerns about the tibial fixation, early aseptic loosening of the tibial component and a revision rate of 60 % at a minimum follow-up of 54 months are reported. Implantation of this prosthesis was stopped at our institution well before the first revision due to an unfavourable early clinical response. This was further endorsed by an unacceptable revision rate. The outcome of the Journey-Deuce bicompartmental knee replacement was considerably worse than the published outcome of total knee replacement.

Fracture of the Tibial Baseplate in Bicompartmental Knee Arthroplasty

Introduction. Bicompartmental knee arthroplasty (BKA) addresses combined medial and patellofemoral compartment osteoarthritis, which is relatively common, and has been proposed as a bridge between unicompartmental and total knee arthroplasty (TKA). Case Presentation. We present the case report of a young active man treated with BKA after unsuccessful conservative therapy. Four years later, loosening with fracture of the tibial baseplate was identified and the patient was revised to TKA. Discussion. Although our case is only the second fractured tibial baseplate to be reported, we believe that the modular titanium design, with two fixation pegs, is too thin to withstand daily cyclic loading powers. Light daily routine use, rather than high-impact sports, is therefore advised. Failures may also be related to the implant being an early generation and known to be technically complex, with too few implant sizes. We currently use TKA for the treatment of medial and patellofemoral compartment osteoarthritis.

Functional Outcomes of a New Mobile-Bearing Ultra-Congruent TKA System: Comparison With the Posterior Stabilized System

We determined whether a new mobile-bearing ultra-congruent (UC) TKA system provides better functional outcomes than an established posterior-stabilized (PS) prosthesis. The functional outcomes (motion arc, AKS scores, WOMAC Index, and SForm-36 scores evaluated at 1 and 2 years postoperatively), satisfaction and incidences of adverse events were compared between the knees implanted with mobile-bearing UC prosthesis (n=103) and the mobile-bearing PS prosthesis (n=99). At 2 years, mobile-bearing UC TKAs showed similar functional outcomes and satisfaction, but smaller motion arc compared to mobile-bearing PS TKAs (126° vs. 131°). There were no differences in the incidence of adverse events. Mobile-bearing UC prosthesis can be considered a safe and viable alternative to the PS design, with an expectation of smaller postoperative maximum flexion.

Kinematics of monoblock bicompartmental knee arthroplasty during weight-bearing activities

PURPOSE

There is an increased interest in treating arthritis of the medial and patellofemoral compartments without using a total knee arthroplasty. The purpose of this study was to measure kinematics in knees with a monoblock bicompartmental arthroplasty to see whether maintaining the cruciate ligaments and lateral compartment resulted in consistent kinematics more similar to healthy knees than those observed in replaced knees.

METHODS

The kinematics of ten knees with monoblock bicompartmental arthroplasty were observed using fluoroscopy during three weight-bearing activities. Model-image registration techniques were used to quantify the three-dimensional motions of the knee joints.

RESULTS

During kneeling, lunging, and stair-step activities, the medial condyle remained relatively close to the centre of the tibial plateau, while the lateral condyle typically moved posteriorly with flexion. Knees generally exhibited motion patterns consistent with retained cruciate ligament function, but individual patterns varied significantly.

CONCLUSIONS

Bicompartmental knee arthroplasty has the potential to retain more natural knee function. Improved tools for aligning the implants and increased implant sizing options may be required to achieve highly consistent results and realize the clinical benefit of a knee arthroplasty with intact cruciate ligaments.

LEVEL OF EVIDENCE

III.