Unicondylar knee replacement versus total knee replacement for the treatment of medial knee osteoarthritis: a systematic review and meta-analysis

Is unicompartmental knee arthroplasty a better choice than total knee arthroplasty for unicompartmental osteoarthritis? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The choice of unicompartmental knee arthroplasty (UKA) vs. total knee arthroplasty (TKA) in the surgical treatment of knee osteoarthritis (KOA) remains controversial. This study aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to compare the clinical results of UKA and TKA for treating unicompartmental KOA.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched for articles published up to January 2, 2023. The literature was rigorously screened to include only RCTs comparing UKA and TKA for unicompartmental KOA. A systematic review and meta-analysis were performed to calculate the mean difference (MD), relative risk (RR), and 95% confidence interval (CI) according to the Cochrane standards.

RESULTS

Thirteen publications involving 683 UKAs and 683 TKAs were analyzed. Except for one study with a follow-up period of 15 years, all outcome measures reported were within 5 years of follow-up. Meta-analysis showed better knee recovery (MD: 1.23; 95% CI: 1.01-1.45; P <0.00001), greater knee function (MD: 1.78; 95% CI: 0.34-3.22; P = 0.02), less pain (MD: 0.75; 95% CI: 0.43-1.06; P <0.00001), and better health status (MD: 3.75; 95% CI: 0.81-6.69; P = 0.01) after UKA than TKA. However, considering the minimal clinically important difference values for these variables, the findings were not clinically relevant. Moreover, UKA patients had fewer complications (RR: 0.59; 95% CI: 0.45-0.78; P = 0.0002) and shorter hospital stays (MD: -0.89; 95% CI: -1.57 to -0.22; P = 0.009) than did TKA patients. There were no statistically significant differences in terms of postoperative range of movement, revision, failure, operation time, and patient satisfaction.

CONCLUSIONS

In terms of clinical efficacy, there was no obvious advantage of UKA over TKA in the surgical treatment of knee OA when considering the minimal clinically important difference. The main advantage of UKA over TKA is that it leads to fewer complications and a shorter length of hospital stay. It is ideal to perform prospective studies with longer follow-up periods to fully evaluate the long-term efficacy and safety of the two procedures in the future.

Unicompartmental knee replacement: controversies and technical considerations

BACKGROUND

Unicompartmental knee replacement (UKR) is one of the effective interventions for the treatment of symptomatic knee osteoarthritis. Moreover, it has multiple advantages over total knee arthroplasty (TKA), including reduced intraoperative blood loss, decreased risk of transfusion, and faster recovery. This study aimed to discuss critical technical considerations regarding UKR and some of the controversies and updates.

METHODS

We conducted a review to provide an overview of the controversies and technical considerations about UKR in several aspects. Only peer-reviewed articles were included, up to December 2023 using PubMed, Google Scholar, ERIC, and Cochrane database for systematic reviews databases.

RESULT

UKR is associated with superior patient-reported clinical and functional outcomes, as well as shorter hospital stays, fewer postoperative complications, and revealed favorable outcomes in patients' return to sport. The choice between mobile- and fixed-bearing prostheses depends, in part, on the surgeon's preference. The mobile-bearing UKR is a less constrained prosthesis and can potentially result in less wear, but it is more technically demanding. While no significant difference between mobile-bearing versus fixed-bearing prostheses, cementless is superior to cemented design. Furthermore, UKR can be a good alternative for high tibial osteotomy (HTO) and still can be considered after a failed HTO. Lastly, recent reviews have shown a revision rate comparable to that of TKA. This is probably influenced by Improved comprehension of the best indications, patient selection criteria, as well as of the design, materials, and technological advances.

CONCLUSION

UKR treatment for unicompartmental knee osteoarthritis is secure and effective. Based on clinical and functional outcomes, decreased morbidity and mortality, and cost-effectiveness, long-term studies suggest that UKR is superior to TKA. Further investigation in this area is warranted.

Return to work following knee arthroplasty: a retrospective review in urban Asian population

BACKGROUND

An increasing number of working adults undergo knee arthroplasty in Singapore. There is limited data concerning Southeast Asian patients returning to work (RTW) following knee replacement surgery. Our aim was to identify and study factors influencing patients RTW following total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA).

METHODS

Patients who underwent TKA or UKA between August 2017 and March 2020 in our center were included in this study. Outcomes include RTW and duration prior to RTW.

RESULTS

441 patients underwent TKA (295 women, 146 men, mean age 67.3 years) and 69 underwent UKA (48 women, 21 men, mean age 61.1 years). Patients who underwent TKA returned to work earlier (mean 83.7 ± 27.1 days) compared to UKA (mean 94.4 ± 42.3 days). 90.0% of TKA patients RTW compared to 95.5% who underwent UKA. Of patients who RTW, 94.3% of the TKA group returned to employment of the same nature compared to 92.9% of UKA patients. Patients who RTW were of a younger age (p = 0.03), white collared workers (p = 0.04), and had independent preoperative ambulatory status (p < 0.01).

CONCLUSION

Younger and independently ambulating patients may have better capacity for rehabilitation and RTW post arthroplasty surgery.

Advantages of Simultaneous Cementless Bilateral Unicondylar Knee Arthroplasty Compared to Staged Surgery

Background

Unicondylar knee arthroplasty (UKA) is an effective procedure, which reduces pain, increases range of motion, and improves function. UKA could be performed simultaneously or in staged sessions. This study aimed to compare bilateral cementless UKA performed simultaneously and in staged sessions in terms of complications, hemoglobin levels, transfusions, and functional outcomes.

Methods

Patients undergoing bilateral UKA for symptomatic medial compartment osteoarthritis were retrospectively analyzed. Of the 73 patients who met the inclusion criteria, 40 underwent surgery simultaneously and 33 underwent surgery in separate sessions. Operative time, length of hospital stay, change in hemoglobin, need for blood transfusion, complications, and functional outcomes were assessed.

Results

There was no statistically significant difference between the two groups in demographic data. Simultaneously operated patients had a significantly shorter hospital stay and shorter operative time. Statistically significant improvements in clinical scores were noted in both groups. The degree of improvement in functional scores did not differ between the groups. There was no difference between the two groups in terms of complication rates, but the number of periprosthetic tibial fractures was higher in the simultaneous group.

Conclusions

Simultaneous bilateral cementless UKA was more advantageous in terms of cumulative hospital stay and total operation time with similar clinical results when compared to a staged procedure. While the overall complication rate was similar, the rate of periprosthetic fractures was 5% in the simultaneous group.

When are patients with osteoarthritis referred for surgery?

Current treatment strategies in hip and knee osteoarthritis (OA) involve a combined approach that includes not only modification of risk factors and conservative treatment but also joint-preserving surgical therapy in the early stages, or joint replacement in late OA. With the recent development of new etiological concepts (i.e. hip dysplasia and femoroacetabular impingement as major risk factors for hip OA), treatment alternatives for joint preservation could be extended significantly. Satisfactory results of osteotomies and other reconstructive procedures around hip and knee joints can only be expected in early OA (Kellgren/Lawrence grade 0-II). If patients with advanced radiographic OA grades III-IV do not respond to conservative treatment over at least 3 months and express a relevant burden of disease, joint replacement might be considered. Prior to surgery, potential contraindications must be excluded, patient expectations need to be discussed, and modifiable risk factors, which may negatively influence the outcome, should be optimized.

Combined unicompartmental knee arthroplasty and anterior cruciate ligament reconstruction in a young patient with post-traumatic arthritis

Post-traumatic arthritis can result in significant pain and difficulty in managing daily life activities. Multiple factors are weighed in selecting the proper surgical intervention, with patient age and level of activity being most important. Isolated osteoarthritis is a well-known indication for unicompartmental knee arthroplasty, where a better range of motion, preservation of natural knee kinematics and less invasive resection of knee joint bone are used. Moreover, the high improvement rate and long-term results after anterior cruciate ligament (ACL) reconstruction and restoration of knee stability can make the combined procedure favourable, particularly for young active patients.We report on an active man in his 30s presenting with isolated medial compartment advanced arthritis after sustaining distal femur intra-articular fracture. He was initially treated with partial unicompartmental knee replacement combined with ACL reconstruction, delivering a good short-term follow-up outcome.Though this case involves just a single patient, the positive outcome suggests that combined partial unicompartmental knee replacement with an ACL reconstruction should be considered for young and active patients diagnosed with isolated advanced medial compartment osteoarthritis.

Early post-operative physiotherapy rehabilitation after primary unilateral unicompartmental knee replacement: a systematic review

BACKGROUND

Unicompartmental Knee Replacement (UKR) is an established treatment for end stage arthritis affecting one compartment of the knee. UKR lends itself to rapid recovery and early discharge. The content, type, timing and dose of early post-operative physiotherapy treatment has yet to be reviewed.

OBJECTIVE

To review the content of early physiotherapy in the first eight weeks following unilateral UKR.

DATA SOURCES

A literature search of Medline, CINAHL, AMED and PubMed and the Physiotherapy Evidence Database (PEDRo) plus citation searching.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) and observational studies reporting a physiotherapy intervention for UKR involving a form of post-operative exercise/education/advice delivered within the first eight weeks of surgery and commencing as an in-patient. Two reviewers independently performed screening, data extraction and risk of bias assessment.

DATA SYNTHESIS

Narrative syntheses were undertaken due to the heterogeneity of the primary outcomes.

RESULTS

Eleven studies were included (n = 1293 participants), three RCTs and eight observational studies. The dose and content of post-operative physiotherapy was highly variable with a move in recent years to rapid recovery and same day discharge with more self-directed rehabilitation. No studies had a low risk of bias.

LIMITATIONS

Small sample sizes and high heterogeneity limit our findings CONCLUSIONS: This review highlights the range of post-operative physiotherapy provision following UKR with a recent move to minimal physiotherapy input. Further research is required to identify those patients who may need additional physiotherapy above that now routinely provided, along with the most effective timing, type, and dosage of the intervention.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42021243238. CONTRIBUTION OF THE PAPER.

Custom total knee arthroplasty combined with personalised alignment grants 94% patient satisfaction at minimum follow-up of 2 years

PURPOSE

The purpose was to report detailed patient-reported outcome measures (PROMs) and satisfaction rates for computed tomography (CT)-based custom TKA at minimum follow-up of 2 years. The hypothesis was that custom TKA combined with 'personalised alignment' would yield equivalent or better PROMs compared to values reported in systematic reviews and meta-analyses on off-the-shelf (OTS) TKA.

METHODS

Of an initial cohort of 150 custom TKAs, four died (unrelated to surgery), one required a revision, and five refused participation, leaving 140 patients for analysis. Patients completed pre- and post-operative PROMs (Oxford Knee Score (OKS), Forgotten Joint Score (FJS), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster osteoarthritis index (WOMAC)) as well as overall level of satisfaction. Proportions that attained a patient acceptable symptom state (PASS) were calculated for OKS and FJS. Clinical findings were compared to the average scores reported for PROMs in recent systematic reviews and/or meta-analyses on OTS TKA. Descriptive statistics were used to summarise the clinical findings as means, standard deviations (SD) and ranges, or numbers and percentages.

RESULTS

At mean follow-up 33.5 ± 4.5 months, 94% (135/143) were either satisfied or very satisfied. Proportions that achieved PASS were 89% for OKS (120/135), and 85% for FJS (118/139). Median OKS, WOMAC and KOOS Symptoms and Pain scores were all within the 4th quartile of medians reported in systematic reviews and/or meta-analyses.

CONCLUSIONS

At a minimum follow-up of two years following custom TKA combined with 'personalised alignment', 94% of patients were either satisfied or very satisfied, and the PASS criteria were achieved in 89% for OKS and 85% for FJS, all of which compare favourably to published outcomes of OTS TKA. Direct comparisons to the literature may not be appropriate, however, considering the heterogeneity of patient demographics and alignment techniques. Randomised controlled trials with sufficient statistical power are needed to corroborate these findings and generalise them to unselected TKA patients.

LEVEL OF EVIDENCE

IV, retrospective cohort study.

Effect of unicompartmental knee arthroplasty combined with arthroscopic debridement on knee osteoarthritis and analysis of risk factors of deep venous thrombosis

OBJECTIVE

To analyze the clinical effect of unicompartmental knee arthroplasty combined with arthroscopic debridement on knee osteoarthritis and the risk factors leading to deep venous thrombosis (DVT).

METHODS

Data of 110 patients with knee osteoarthritis admitted to The People's Hospital of Wenjiang Chengdu for surgical treatment from February 2019 to June 2021 were retrospectively analyzed. According to the surgical treatment methods, 58 patients treated with unicompartmental knee arthroplasty were included in the control group. The remaining 52 patients with combined treatment of unicompartmental knee arthroplasty and arthroscopic knee debridement were included in the observation group. The therapeutic effect, knee joint function score, Visual Analogue Scale (VAS) score, time required for knee flexion of 90°, length of hospital stay, and incidence of postoperative DVT were compared between the two groups 1 month after the operation. Risk factors leading to the development of DVT were analyzed.

RESULTS

One month after the operation, the overall response rate, knee joint function score, and VAS score in the observation group were significantly better than those in the control group. The time required for knee flexion of 90° and length of hospital stay were shorter and the incidence of DVT was lower in the observation group than those in the control group. According to the occurrence of DVT, patients were divided into a DVT group and a non-DVT group. The univariate analysis revealed that age, body mass index, history of diabetes, coagulation parameters, and surgical methods were related to the occurrence of DVT. The logistics regression analysis revealed that age, body mass index, coagulation parameters, and surgical methods were independent risk factors affecting the occurrence of postoperative DVT.

CONCLUSION

The combined treatment of unicompartmental knee arthroplasty and arthroscopic debridement can significantly improve knee joint function and bone metabolism and reduce the incidence of postoperative DVT of patients with knee osteoarthritis, achieving a more satisfactory therapeutic effect.

Unicompartmental Knee Arthroplasty Has Lower Infection, Conversion, and Complication Rates Compared to High Tibial Osteotomy

INTRODUCTION

 Isolated medial knee osteoarthritis can be surgically treated with either unicompartmental knee arthroplasty (UKA) or high tibial osteotomy (HTO). Proponents of UKA suggest superior survivorship, while HTO offers theoretically improved alignment and joint preservation delaying total knee arthroplasty (TKA). Therefore, we compared complications in a large population of patients undergoing UKAs or HTOs. We specifically assessed 90 days, 1 year, and 2 years: (1) periprosthetic joint infection (PJI) rates, (2) conversion to TKA rates, as well as (3) complication rates.

METHODS

 A review of an administrative claims database was used to identify patients undergoing primary UKA (n = 13,674) or HTO (n = 1,096) from January 1, 2010 to December 31, 2019. Complication rates at 90 days, 1 year, and 2 years were compared between groups using unadjusted odds ratios (ORs) with 95% confidence intervals. Subsequently, multivariate logistic regressions were performed for PJI and conversion to TKA rates.

RESULTS

 At all time points, patients who underwent UKA were associated with lower rates of infection compared with those who underwent HTOs (all OR ≤ 0.51, all p ≤ 0.010). After 1 year, patients who received UKAs were found to have lower risk of requiring a conversion to a TKA versus those who received HTOs (all OR ≤ 0.55, all p < 0.001). Complications such as dislocations, periprosthetic fractures, and surgical site infections were found at lower odds in UKA compared with HTO patients.

CONCLUSION

 This study provides large-scale analyses demonstrating that UKA is associated with lower infection rates and fewer conversions to TKA compared with patients who have undergone HTO. Dislocations, periprosthetic fractures, and surgical site infections were also found to be lower among UKA patients. However, with careful patient selection, good results and preservation of the native knee are achieved with HTOs. Therefore, UKA versus HTO may be an important discussion to have with patients in an effort to lower the incidence of postoperative infections and complications.

Safety and Efficacy of Single Condylar Knee Prosthesis When Treating Knee Single Compartment Osteoarthritis: A Prospective, Case-Randomized Controlled Study

Objective. The aim of this study is to explore the safety and efficacy of single condylar knee prosthesis when treating knee single compartment osteoarthritis by measuring the decrease of hemoglobin, total postoperative blood loss, maximum reduction of HCT, and knee joint activity. Methods. A total of 80 patients with knee joint single compartment osteoarthritis treated in our hospital from January 2020 to December 2021 were studied. They were randomly assigned to a study group (n = 40) and a control group (n = 40). The study group was treated with total knee prosthesis, while the control group was treated with simple knee prosthesis. The decrease rate of hemoglobin, the amount of bleeding, and the maximum decrease of hematocrit were compared after treatment. The range of motion of knee joint was evaluated by the Fugl-Meyer motor function scale (FM-B) and Berg balance scale (BBS). Results. The decrease of hemoglobin in the study group at 24 hours, 36 hours, and 48 hours after treatment was remarkably lower ( $P$  < 0.05). The total blood loss and the maximum reduction of hematocrit(HCT) in the study group were lower ( $P$  < 0.05). The range of motion (ROM) of the knee joint in the study group at 6 and 12 months after treatment was remarkably higher than that before treatment and remarkably higher compared to the control group ( $P$  < 0.05). The FM-B scale and BBS scale of the studied cohort at 6 and 12 months after treatment were remarkably higher than those before treatment and were remarkably higher compared to the control’s ( $P$  < 0.05). Conclusion. The unicondylar knee prosthesis is safer and more effective in the treatment of noncompartmental osteoarthritis of the knee, facilitating less trauma and perioperative blood loss and enhancing the patient’s motion and balance.

Minimally invasive Oxford medial unicompartmental knee replacement in patients 50 years of age or younger

INTRODUCTION

The aim of the present study was to assess clinical outcome and mid-term survivorship of mobile-bearing unicompartmental knee arthroplasty in patients 50 years of age or younger.

METHODS

This study reports the results of 119 patients (130 knees) following mobile-bearing medial UKA. Primary indication was advanced osteoarthritis or avascular necrosis of the femoral condyle. The anterior cruciate ligament (ACL) as well as the collateral ligaments were functionally intact, the varus deformity was manually correctable and there was no evidence of osteoarthritis in the lateral compartment. Survivorship analysis was performed with different endpoints and clinical outcome was measured using the Oxford Knee Score (OKS), American Knee Society Score and Functional Score (AKSS-O, AKSS-F), range of motion (ROM), Tegner activity score, University of California Los Angeles score (UCLA) and visual analogue scale for pain (VAS).

RESULTS

The survival rate was 96.6% at 6.5 years (95% CI 98.7-91.3%; number at risk: 56) and 91.7% (95% CI 96.7-80%; number at risk: 22) at 10 years for the endpoint device related revisions and 91.5% at 6.5 years (95% CI 95.4-84.5%; number at risk: 56) and 86.8% (95% CI 93-76.2%; number at risk: 22) at 10 years for the endpoint revision for any reason. Outcome scores, VAS and ROM showed significant improvements (p < 0.001). The mean OKS increased from 26.7 (standard deviation (sd): 7.2) preoperatively to 40.9 (sd: 7.6) at final follow-up, the mean AKSS-O from 48.3 (sd: 13.3) to 87.8 (sd: 14.4) and the mean ROM from 118° (sd: 16.7) to 125° (sd: 11.4). The radiological analysis revealed progression of degenerative changes in the lateral compartment in 39.6% of patients without affecting the functional outcome.

CONCLUSIONS

Medial mobile-bearing UKA is a viable surgical treatment option in young patients with significant improvements in knee function and pain. Further follow-up is necessary to evaluate the long-term efficacy.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

Sprifermin: Effects on Cartilage Homeostasis and Therapeutic Prospects in Cartilage-Related Diseases

When suffering from osteoarthritis (OA), articular cartilage homeostasis is out of balance and the living quality declines. The treatment of knee OA has always been an unsolved problem in the world. At present, symptomatic treatment is mainly adopted for OA. Drug therapy is mainly used to relieve pain symptoms, but often accompanied with adverse reactions; surgical treatment involves the problem of poor integration between the repaired or transplanted tissues and the natural cartilage, leading to the failure of repair. Biotherapy which aims to promote cartilage in situ regeneration and to restore endochondral homeostasis is expected to be an effective method for the prevention and treatment of OA. Disease-modifying osteoarthritis drugs (DMOADs) are intended for targeted treatment of OA. The DMOADs prevent excessive destruction of articular cartilage through anti-catabolism and stimulate tissue regeneration via excitoanabolic effects. Sprifermin (recombinant human FGF18, rhFGF18) is an effective DMOAD, which can not only promote the proliferation of articular chondrocyte and the synthesis of extracellular matrix, increase the thickness of cartilage in a dose-dependent manner, but also inhibit the activity of proteolytic enzymes and remarkedly slow down the degeneration of cartilage. This paper reviews the unique advantages of Sprifermin in repairing cartilage injury and improving cartilage homeostasis, aiming to provide an important strategy for the effective prevention and treatment of cartilage injury-related diseases.

Comparison of Pain, Muscle Strength, and Functional Status Following Unicompartmental Knee Arthroplasty, Total Knee Arthroplasty, and Conservative Management of Gonarthrosis

BACKGROUND

Treatment options and surgical decision for grade 3-4 gonarthrosis remains controversial. We aimed to compare the pain level, muscle strength, physical performance, lower extremity functions, and other physical activity levels between patients who underwent arthroplasty and those who received conservative management for grade 3-4 gonarthrosis.

METHODS

This prospective analytical observational study was conducted in a tertiary referral hospital. A total of 30 unicompartmental knee arthroplasty (UKA) and 30 total knee arthroplasty (TKA) patients as two different study groups and 30 patients were treated conservatively as the control group were included. The rehabilitation and complication rates were recorded. The values of the range of motion, quadriceps diameter, were measured and also the isokinetic muscle strength, pick-up, repeated sit-to-stand, stair ascending and descending, straight-line walking, timed up and go, and 20-m walk tests, the knee injury and osteoarthritis-outcome-score (KOOS), the hospital for special-surgery-knee-score (HSS), and Oxford-Knee-Score (OKS) were performed.

RESULTS

Postoperative rehabilitation and complication rates were significantly higher in the TKA group compared to the UKA group (p = 0.029 and p = 0.026, respectively). Six months after the treatment, the knee extension muscle strength value at 180°/s, knee flexion degree, total work flexion, stair ascending, VAS at night, all KOOS symptom, pain and daily function and total scores in the UKA group was significantly different than the TKA and the control groups (p < 0.001). Total work extension values, knee flexion degree, in the control group were found to be significantly higher than the TKA group (p = 0.033, p < 0.001, respectively).

CONCLUSIONS

The UKA was significantly superior to TKA and conservative treatment concerning pain, muscle strength, and quality of life.

LEVEL OF EVIDENCE

IIa.

Does bicompartmental knee arthroplasty hold an advantage over total knee arthroplasty? Systematic review and meta-analysis

INTRODUCTION

The role of bicompartmental knee arthroplasty (BKA) in the treatment of medial patellofemoral osteoarthritis (MPFOA) has been debated by orthopaedic surgeons for years. The BKA is a cruciate ligament retaining prosthesis designed to mimic the kinematics of the native knee that requires resurfacing of only two knee compartments. In this study, we aim to assess the patient recorded outcome measures (PROMs), range of motion (ROM), perioperative morbidity, and implant revision rate in patients undergoing BKA and compare them to those undergoing total knee arthroplasty (TKA) for bicompartmental knee osteoarthritis (OA).

PATIENTS AND METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement (PRISMA). Articles from any country and written in any language were considered. We included all randomized control trials and retrospective cohort studies examining BKA versus TKA for bicompartmental knee OA. The primary outcome measure was knee society score (KSS) at one year and the secondary outcome measures were Oxford knee score (OKS) and short-form survey (SF-)12 at six and twelve months.

RESULTS

We included five studies in our meta-analysis. In terms of OKS, KSS, and SF-12, our meta-analysis suggests better short-term results for the TKA compared with the BKA. TKA was also associated with a shorter operative time and a lower revision rate. The BKA implant did however result in marginally less intraoperative blood loss and slightly better post-operative ROM.

CONCLUSIONS

BKA did not prove to be an equivalent alternative to TKA in bicompartmental knee OA. It was associated with inferior KSS, OKS, and SF-12 at short-term follow-up and a higher revision rate.