Patellofemoral Joint Replacement Research Articles

Patellofemoral joint replacement—better than its reputation?

Patellofemoral joint replacement—better than its reputation?

OUTCOME AFTER AVON PATELLOFEMORAL JOINT REPLACEMENT IN PATIENTS UNDER 55 YEARS OLD: LOW REVISION RATE AT MID-TERM FOLLOW-UP FROM AN INDEPENDENT CENTRE

AbstractIntroductionIsolated patellofemoral osteoarthritis accounts for 10% of knee osteoarthritis. Many of these will not require arthroplasty solutions, but for those who are sufficiently symptomatic, patellofemoral joint (PFJ) replacement has been shown to be an effective procedure. The National Joint Registry (NJR) has shown a higher revision rate for this operation, particularly in younger patients (males <55 years 13.3% failure at 5 years, females 9.6%). The aim of this study is to report on the medium-term outcome of the Avon patellofemoral joint arthroplasty in patients under 55 from a non-design centre. There is no other published case series on this young patient cohort.Methodology50 Avon PFJ replacements (Stryker, Kalamazoo USA) were undertaken in 46 patients under 55 years old (range 35 – 54, mean 48.8) between 2010 and 2022 for end-stage isolated PFJ arthritis shown on Xray and MRI scan. The outcome measure was all-cause revision rate. This was assessed by review of clinical notes, imaging and NJR data.ResultsThe mean follow up was 5.8 years (range 6 months to 12.9 years). Only one patient had a revision procedure (for progressive osteoarthritis) which was 3 years after the primary procedure. This patient has had no further surgery. The implant survival rate was 97.2% at 5 years and 97.2% at 10 years.ConclusionThis study shows that patellofemoral joint replacement with the Avon prosthesis can give a satisfactory revision rate in the medium term in patients under 55 if carefully selected.

OUTCOME OF REVISION PATELLOFEMORAL JOINT REPLACEMENT TO TOTAL KNEE ARTHROPLASTY WHEN COMPARED WITH A MATCHED GROUP OF TOTAL KNEE ARTHROPLASTY OF SAME TOTAL ARTHROPLASTY LIFESPAN

AbstractINTRODUCTION10% of patients with knee osteoarthritis (OA) have disease confined to the patellofemoral joint (PFJ). The main surgical options are total knee replacement (TKR) and PFJ replacement (PFJR). PFJR has advantages over TKR, including being less invasive, bone preserving, allowing faster recovery and better function and more ‘straight forward’ revision surgery. We aim to compare the clinical results of revised PFJR with primary TKR taking into consideration the survival length of the PFJR.METHODOLOGYTwenty-five patients (21 female) were retrospectively identified from our arthroplasty database who had undergone revision from PFJR to TKR (2006–2019). These patients were then matched with regards to their age at their primary procedure, sex and total arthroplasty life (primary PFJ survival + Revision PFJ time to follow up) up to point of follow-up with a group of primary TKRs implanted at the same point as the primary PFJR.RESULTSMean survival of the PFJs revised were 4.2 years. In the PFJR revision group (mean arthroplasty life 7.8 years) mean Oxford knee score (OKS) at latest follow up was 27.8. In the primary knee group (mean arthroplasty life 7.5 years) mean OKS was 32.4. This difference was not statistically significant. All PFJR revisions were performed using primary prostheses.CONCLUSIONPFJR provides comparable clinical outcome even after revision surgery to TKR as primary TKRs at midterm follow up and should be considered in all patients meeting the selection criteria. Given comparable proms and straight forward revisions, staged arthroplasty to preserve bone-stock is a reasonable choice.

International primary knee arthroplasty registry review: findings from current reports.

International joint registries provide high volumes of information in relation to the performance of total knee arthroplasty on a global scale. Distillation of this data can be challenging, particularly with the establishment of more arthroplasty registries on a yearly basis. We therefore aim to present key information from these registries in relation to primary total knee arthroplasty. The specific questions of interest include: Which fixation type is superior in TKA? Does the level of constraint impact on clinical performance? How do partial knee replacements perform in the registries? Does patellar resurfacing lead to superior results? Are there any specific implants which perform particularly well or poorly? A comprehensive review of the major English-speaking knee arthroplasty registries across the globe was performed. Given the expanding large number of registries worldwide, it was not possible to perform a comprehensive review of all registries and so, a detailed review of the major English-speaking knee arthroplasty registries was included. Key trends and developments in implant performance were identified and presented in the current article. Total knee replacements have lower revision rates than both unicompartmental and patellofemoral joint replacement procedures. Patellofemoral joint replacements have the highest failure rate of all knee replacement procedures. Cruciate-Retaining (CR) TKR designs have superior outcomes to Posterior-Stabilized (PS) designs across all registries. Patellar resurfacing appears to confer an advantage over non-resurfaced patellas in primary TKR. We present current global trends in the utility and performance of TKA based on data from English-speaking arthroplasty registries.

Robotic Assisted Patellofemoral Joint Replacement: Surgical Technique, Tips and Tricks.

In this article we wish to provide MAKO robotic knee users a surgical guide including tips and tricks on performing MAKO robotic-assisted patellofemoral joint replacements. The senior authors in this paper from the Exeter Knee Reconstruction Unit, United Kingdom are highly experienced MAKO users who have been performing MAKO assisted Patellofemoral joint replacements since 2017.

Treatment of Unicompartmental Cartilage Defects of the Knee with Unicompartmental Knee Arthroplasty, Patellofemoral Partial Knee Arthroplasty or Focal Resurfacing

Focal chondral defects are common lesions of the articular cartilage. They are predominantly found on the medial femoral condyle and often progress to osteoarthritis of the knee. Various conservative treatment options are available. The conservative treatment might reduce pain and delay the progress of degenerative processes. However, restoration of the articular cartilage cannot be accomplished. If the conservative treatment fails unicompartmental arthroplasty, patellofemoral joint replacement or focal resurfacing are reasonable options to postpone total knee arthroplasty. A careful patient selection before surgery is crucial for all three treatment options. The following overview reports indications and outcomes of medial partial knee replacement, patellofemoral partial knee replacement, and focal resurfacing treatment options for focal chondral defects.

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

PurposeCombined 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 methodsThis 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.ResultsSignificant 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.ConclusionThe 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.

Patellofemoral arthroplasty for the treatment of patellofemoral arthritis

To explore the clinical effect of patellofemoral joint replacement in the treatment of patellofemoral arthritis. From July 2013 to June 2017, 35 patients with 42 knees underwent patellofemoral arthroplasty, including 34 females and 1 male, aged 45 to 70 (55.0±8.2) years old, with a course of 6 to 36 (13.7±2.5) months. Before and at the end of the follow-up, the patients were assessed with Oxford knee score, satisfaction with the operation was assessed at the end of the follow-up. In addition, X-ray films of the front and side of the knee joint and axial films of the patella were taken to assess whether the prosthesis was loose, and complications such as hematoma and joint infection were recorded. Forty-two knees of 35 patients were followed up for 18 to 65 (35.0±7.2) months, and the operation time was (56.2±8.7) min. Oxford knee joint score increased from preoperative 28.14±0.36 to 37.19±0.47 at the end of the follow-up (P<0.05) . The score of pain items increased from preoperative 10.12±0.26 to 15.83±0.30 at the end of the follow-up, and the score of functional items increased from preoperative 18.02±0.13 to 21.36±0.23 at the end of the follow-up (P<0.05) , there was statistical significance (P <0.05) . In one case, there was wound suture reaction in the early postoperative period, which was improved after debridement; in the other case, there was swelling around the wound 5 weeks after operation, which was improved after antibiotic treatment; in one case, there was tear at the suture of quadriceps femoris muscle at 1 month after operation, which was improved after re suture; no loosening of prosthesis was found. The second generation of patellofemoral arthroplasty for the treatment of simple severe patellofemoral arthritis has satisfactory early clinical effect and few complications, but the indication of operation should be strictly grasped. For severe cases, CT scan of knee joint can be used to customize the patellofemoral prosthesis, so as to reduce postoperative complications and improve the clinical effect.

Risk factors for early revision after total hip and knee arthroplasty: National observational study from a surgeon and population perspective.

AimsTo identify predictors of early revision (within 3 years of the index operation) for hip and knee replacement (HR, KR) from both surgeon and population perspectives.Patients and methodsHierarchical logistic regression on national administrative data for England for index procedures between April 2009 and March 2014.ResultsThere were 315,273 index HR procedures and 374,530 index KR procedures for analysis. Three-year revision rates were 2.1% for HR and 2.2% for KR. The highest odds ratios for HR were for 3+ previous emergency admissions, drug abuse, Parkinson’s disease, resurfacing and ages under 60; for KR these were patellofemoral or partial joint replacement, 3+ previous emergency admissions, paralysis and ages under 60. Smaller effects were found for other comorbidities such as obesity (HR) and diabetes (KR). From a population perspective, the only population attributable fractions over 5% were for male gender, uncemented total hip replacements and partial knee or patellofemoral replacements.ConclusionsMeeting the rising demand for revision surgery is a challenge for healthcare leaders and policymakers. Our findings suggest optimising patients pre-operatively and improving patient selection for primary arthroplasty may reduce the burden of early revision of arthroplasty. Our study gives useful information on the additional risks of various comorbidities and procedures, which enables a more informed consent process.Clinical relevanceSurgeons should make patients with certain risk factors such as age and procedure type aware of their higher revision risk as part of shared decision-making.

Patellar tendon shortening following patellofemoral joint replacement.

Patellar tendon shortening may occur following patellofemoral joint replacement (PFJR). We hypothesized that patellar tendon shortening results in unfavourable patient-reported outcomes (PROs). The aim of this study was to determine the effect of patellar tendon shortening following PFJR on PROs. In this substudy of a prospective cohort study, a total of 108 patients with isolated patellofemoral osteoarthritis underwent 124 patellofemoral joint replacements. We measured both patellar tendon length and length of the patella on pre-operative radiographs, and on radiographs acquired at eight weeks and at one year post-operative. More than 10% decrease in patellar tendon length relative to the pre-operative patellar tendon length was defined as patellar tendon shortening. Clinical outcomes were assessed using the knee-specific KOOS questionnaire (Knee Injury and Osteoarthritis Outcome Score). Repeated measures ANOVA was used to analyze for differences in change from baseline KOOS subscales between patients with and patients without patellar tendon shortening. A complete series of standardized pre-operative, eight weeks and one year post-operative radiographs was available for 87 knees in 82 patients. At eightweeks, 16 of 87 knees (18%) showed patellar tendon length shortening, and 27 of 87 knees (31%) at one year. We found no statistically significant relation between patellar tendon length shortening and change from baseline KOOS subscales at one year follow-up (pain p = 0.29, symptoms p = 0.56, ADL p = 0.23, sport or recreation p = 0.22, knee-related quality of life (QOL) p = 0.15). Patellar tendon length shortening following PFJR occurs in 31% of knees at one year, and does not result in inferior PROs.

Patellofemoral joint replacement — Mean five year follow-up

BackgroundThe Femoro Patella Vialli FPV is a second-generation patellofemoral arthroplasty implant. It is the second most commonly used patellofemoral implant in the National Joint Registry of England and Wales. This is the first published mid-term outcome series for this prosthesis. MethodsWe reviewed the outcomes for all patients who had patellofemoral arthroplasty. Primary outcome was the intention to revise the implant; secondary outcome measures were Oxford and Kujala outcome scores. ResultsA total of 43 FPV patellofemoral joint prostheses were implanted in 32 patients at our institution between April 2004 and December 2012. Mean follow-up was 65 (30–119) months. Only one patient was lost to follow-up. At final follow-up the mean flexion was 110° (85°–130°). Five of 43 knees required revision to a total knee replacement because of progressive tibiofemoral osteoarthritis. Revisionswere carried out after amean of 56 months (30–109). There was no radiographic loosening in any case. The most recent functional assessment showed that the mean Oxford Knee score (OKS) has improved from 18 (five to 35) preoperatively to 29 (nine to 45) and the Kujala score from 35 (five to 74) preoperatively to 58 (18–91). ConclusionsMidterm results with FPV prosthesis demonstrate that moderate outcomes can be achieved. Patellofemoral arthroplasty may be used to delay total knee replacement but judicious patient selection to identify truly isolated patellofemoral osteoarthritis is necessary. Chondral lesion in weight bearing area can lead to early implant failure. The main cause of failure was progressive tibiofemoral osteoarthritis.

Progress on treatment for patellofemoral arthritis

As a common disease of knee joint disease, the diagnosis and treatment of patellofemoral arthritis has not clear clinical consensus at present, conservative treatment only has a certain value for the disease with early stage and single disease. With the continuous improvement of understanding of pathogenesis and advancement of surgical techniques, minimally invasive and joint replacement technology has been rapid development, more and more alternative treatment options could be chosen. Technique of osteotomy of tibial tuberosity and removal of patella at the early stage were seldom used. According to development stage of disease, and combined with age, economic capacity, patients considering knee joint functional requirements and other factors, the balance of soft tissue under arthroscopy and denervation for cartilage injury in elderly patients with grade I to III surgery is more appropriate, and joint replacement is effective for cartilage injury in elderly patients with grade IV. Early debate is focus on total knee arthroplasty whether exist excessive medical treatment, patellofemoral joint replacement meet to demand for replacement of single patellofemoral degeneration with improvement of prosthesis design. Due to technical difficulties of cartilage transplantation and anatomical characteristics of patellofemoral joint, report of application of cartilage transplantation for patellofemoral arthritis is less, but with continuous improvement of technology, cartilage transplantation will be a good method for improving clinical symptoms, reducing medical costs, putting off joint replacement time.

Advances in Patellofemoral Arthroplasty.

To describe current indications, implants, economic benefits, comparison to TKA, and functional and patient-reported outcomes of patellofemoral arthroplasty. Modern onlay implants and improved patient selection have allowed for recent improvements in short- and long-term outcomes after patellofemoral joint replacement surgery. Patellofemoral arthroplasty has become an increasingly utilized technique for the successful treatment of isolated patellofemoral arthritis. Advances in patient selection, implant design, and surgical technique have resulted in improved performance and longevity of these implants. Although short- and mid-term data for modern patellofemoral arthroplasties appear promising, further long-term clinical studies are needed to evaluate how new designs and technologies will affect patient outcomes and long-term implant performance.

Femoral component rotation in patellofemoral joint replacement

BackgroundClinical outcomes in patellofemoral joint replacement may be related to femoral component rotation. Assessment of rotational alignment is however difficult as patients with isolated patellofemoral osteoarthritis often have trochlear dysplasia. The use of the medial malleolus as a landmark to guide rotation has been suggested. The purpose of our study was to evaluate this technique with regard to femoral component rotation, and to correlate rotation with clinical outcomes at one-year follow-up. MethodsForty-one knees in 39 patients had patellofemoral joint replacement using the Zimmer Gender-Solutions patellofemoral prosthesis. Intraoperatively, we determined femoral component rotational alignment using an extramedullary rod aimed at the inferior tip of the medial malleolus. Postoperatively, we measured the angle between the femoral component and the anatomical transepicondylar axis using CT. The amount of rotation was correlated with clinical outcomes at one-year follow-up. ResultsForty knees in 38 patients were available for one-year follow-up. Mean femoral component rotation relative to the anatomical transepicondylar axis was 1.4° external rotation (range, −3.8 to 5.7°). We found no statistically significant correlation between femoral component rotation and change from baseline KOOS subscales at one-year follow-up. ConclusionsOur findings show that when using the medial malleolus as a landmark to guide rotation, the femoral component of the patellofemoral prosthesis was oriented in external rotation relative to the anatomical transepicondylar axis in 80% of knees. Our study did not show a relation between the amount of external rotation and clinical outcomes. Level of evidenceLevel III.

Mid-term survivorship and clinical outcomes of the Avon patellofemoral joint replacement

BackgroundWe present the largest series of Avon patellofemoral joint (PFJ) replacements outside of the design centre. There is discussion over its efficacy and usefulness. We report an independent opinion of its indications, survivorship and outcomes. MethodsWe prospectively collected demographic data and patient reported outcome measures (PROM's) on our cohort of Avon Patellofemoral replacements since its adoption in our unit in 2003 until 2014. We performed a retrospective review of radiographs. ResultsWe performed 103 PFJ replacements in 85 patients, 36 were male (mean age 61 - range 34 to 78) and 67 female (mean age 60 - range 38 to 82), mean follow up time was 5.6years (range 2.9 to 14.2years) with 93 implants still in situ. Their mean post-operative Oxford Knee Score was 36 (range seven to 48). There were nine conversions to TKR for disease progression and one revision of a femoral component for trochlear malpositioning. Mean time to revision was 2.9years (1.0 to 6.0years). Radiographic evidence of progression on Kellgren and Lawrence score in the un-replaced compartments was demonstrated in 23% of cases with imaging available.The Avon PFJ replacement delivers reproducible and effective pain relief and function to patients with isolated patellofemoral osteoarthritis. We believe PFJ replacement has an important role to play, and we will continue to perform this procedure for a carefully selected group of patients. Conversion to TKR does not and should not be regarded as failure of the index operation.

Patellofemoral Joint Arthroplasty: Early Results and Functional Outcome of the Zimmer Gender Solutions Patello-Femoral Joint System.

BackgroundImproved knee prosthesis designs have led to an increase in the use of patellofemoral arthroplasty as a primary treatment option in recent times. We report the early results and outcomes of the Zimmer Gender Solutions Patello-Femoral Joint (PFJ) system used to treat isolated patellofemoral osteoarthritis (PFA).MethodsWe retrospectively reviewed and analysed data of patients who underwent PFJ replacement (PFJR) at our institution with a minimum follow-up of 2 years.ResultsMedian Oxford Knee score (OKS) was 38 (interquartile range, 28 to 42) at the latest follow-up with a significant improvement from preoperative scores (p < 0.0005). Median OKS was 40 for unilateral PFJRs and 39 for nonobese patients (body mass index [BMI] < 30 kg/m2). There was no significant difference in OKS between unilateral and bilateral procedures (p = 0.462). Likewise, there was no significant difference in OKS between obese and nonobese patients (p = 0.272). Two knees (4%) were revised for progression of osteoarthritis. No complications were reported related to infectious or thromboembolic causes.ConclusionsOur study showed good early results of the PFJ system, at least equal to those of other leading brands in the National Joint Registry for England, Wales and Northern Ireland (NJR). There have been no complications related to either the implantation technique or prosthetic design for this new implant. Progression of tibiofemoral arthritis remains a major concern. Our study also suggests that PFJR in obese patients and bilateral procedures can have good results.

Our Experience with Patello femoral joint replacement

Background:Ten to fifteen percent of knee arthritis is reported to be isolated patellofemoral arthritis. Total knee arthroplasty is not recommended for isolated patella femoral arthritis particularly in young patients. We present the retrospective review our series in 7 years.Objectives:The aim of this presentation is to describe our experience in the management of patellofemoral osteoarthritis with the use of the partial patellofemoral arthroplasty, as well as to delineate the pitfalls and causes of revision in our initial series of 153 cases.Methods:between 2009 and 2016, our group performed 157 patellofemoral arthroplasties (PFA) 74% being in women, and 26% in men, the mean age for women was 58 yrs. And 38 yrs. for men, our initial 13 cases were managed with the Avon prosthesis (Stryker Corporation Kalamazoo, Michigan), and then we switched to the Vanguard PF (Zimmer-Biomet Warsaw In), both systems are an On-Lay design that is more flexible for addressing dysplastic trochleas that are more common in our population.Results:We performed a Knee Osteoarthritis Outcome Score (KOOS) for the assessment of the success of the procedure and obtained 87% of patients with excellent results (95 to 100), 10% with fair results (70 to 90) and 3% with poor outcomes (50), we performed a total of 3 revisions due to pain or progress to global arthritis.Conclusion:The PFA is a successful, safe and reproducible surgery that can be used in the group of patients that have isolated patellofemoral osteoarthritis. It requires a thorough knowledge of the patello femoral joint biomechanics, and physiopathology.

Mid-term Results of Isolated Patello-femoral Joint Replacement for Patello-Femoral Joint Arthritis: A United Kingdom District General Hospital Experience

Mid-term Results of Isolated Patello-femoral Joint Replacement for Patello-Femoral Joint Arthritis: A United Kingdom District General Hospital Experience

Femoro Patella Vialla patellofemoral arthroplasty: An independent assessment of outcomes at minimum 2-year follow-up

To determine outcomes using the Femoro-Patella Vialla (FPV) arthroplasty and if there is an ideal patient for this implant. A total of 41 FPV patellofemoral joint replacements were performed in 31 patients (22 females, 9 males, mean age 65 years). Mean follow-up was 3.2 years (minimum 2 years). Radiographs were reviewed preoperatively and postoperatively. We assessed whether gender, age, previous surgery, patella atla or trochlear dysplasia influenced patient satisfaction or patient functional outcome. The median Oxford Knee Score was 40 and the median Melbourne Patellofemoral Score was 21 postoperatively. Seventy-six percent of patients were satisfied, 10% unsure and 14% dissatisfied postoperatively. There was no radiological progression of tibiofemoral joint arthritis, using the Ahlback grading, in any patient. One patient, who was diagnosed with rheumatoid arthritis postoperatively, underwent revision to total knee replacement. There were no intraoperative lateral releases and no implant failures. Gender, age, the presence of trochlear dysplasia, patella alta or bilateral surgery did not influence patient outcome. Previous surgery did not correlate with outcome. In contrast to the current literature, the FPV shows promising early results. However, we cannot identify a subgroup of patients with superior outcomes.

Femoral component rotation in patellofemoral joint replacement: a study protocol for a prospective observational study.

Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. The short and mid-term outcomes are related to malposition and unexplained pain. Whether external rotation of the femoral component in isolated patellofemoral joint replacement is required is unclear. The primary aim of this study is to determine the CT-measured femoral component rotation of patellofemoral joint replacement relative to the transepicondylar axis. The secondary aim is to correlate the CT-measured femoral component rotation with the clinical outcomes at 1-year follow-up as assessed with the KOOS questionnaire.We designed a prospective observational study with medical research ethics committee and institutional review board approval. A total of 40 patients who will be treated with patellofemoral joint replacement for isolated patellofemoral osteoarthritis will be included. Intra-operatively, rotation of the femoral component will be assessed using anatomical landmarks including the epicondylar axis, Whiteside’s line, and lower leg axis. The aim is to insert the femoral component between 3 and 6 degrees external rotation relative to the transepicondylar axis. Two experienced musculoskeletal radiologists will measure the angle between the transepicondylar axis and the femoral component, two to three days after surgery. The primary outcome is the CT-based femoral component rotation of the prosthesis relative to the transepicondylar axis. The secondary outcome is the patient reported KOOS questionnaire at 1-year follow-up.Successful completion of this study will provide data on the actual amount of femoral component rotation in patellofemoral joint replacement, and its relationship with clinical results. (Netherlands Trial Register NTR4175).