Patients return to work sooner after unicompartmental knee arthroplasty than after total knee arthroplasty

Patient Satisfaction Following Unicompartmental Knee Arthroplasty: Current Concepts

Unicompartmental knee arthroplasty (UKA) has gained progressive popularity in recent decades, currently comprising approximately 10% of knee arthroplasties in the United States. Nonetheless, UKA has not yet solidified its position as the superior treatment for isolated compartment osteoarthritis, as initial reported implant survivorship was subpar, leading to hesitation in its utilization and stricter patient indications compared to total knee arthroplasty. Patient satisfaction following knee arthroplasty has emerged as a critical metric to gauge patient acceptance and contentment with surgical interventions. Currently, a variety of UKA types exist, differing in bearing design, fixation techniques such as cementless or cemented fixation, and robotic-assisted systems, each with its own merits and drawbacks. Multiple studies have demonstrated the contributions of these innovations to improve clinical outcomes and implant survivorship. However, the abundance of studies has made it challenging to establish a clear overview. This paper provides an overview of the current concepts of UKA, evaluating various aspects of UKA referencing to patient satisfaction and providing a recap of its historical development. Available research demonstrated no significantly universal superior variant of UKA.

Improvements in Noise Symptoms, Forgotten Joint Scores, and Functional Outcomes With Greater Time Following Total Knee Arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is an impactful procedure with goals that include pain reduction and improved function, with low levels of prosthesis awareness. The purpose of this study was to determine if patients reported prosthetic noise and noise-related symptoms diminished over the course of time after TKA.

METHODS

This study was a single institutional, retrospective study of patients who underwent primary unilateral TKA from 2018 to 2021. The TKAs were performed by four high-volume, fellowship-trained arthroplasty surgeons. Patients had similar baseline characteristics. Patients completed a survey consisting of four Likert scale questions related to prosthetic noise generation, the Forgotten Joint Score, and the Knee Injury and Osteoarthritis Outcome Score-Joint Replacement. Data were compared between patients who had undergone TKA one to two years earlier (N = 305) and those who had TKA three to four years prior to evaluation (N = 177).

RESULTS

After more time with TKA, patients had significantly lower reports of hearing noise (31.1 versus 43.6%; P = 0.009) and feeling prosthetic noise-related symptoms (28.2 versus 40.3%; P = 0.010). Furthermore, after more time from TKA, patients had significantly higher satisfaction regarding noise-generation (65.5 versus 50.2%; P = 0.012), postoperative Knee Injury and Osteoarthritis Outcome Score-Joint Replacement scores (80.9 versus 75.9; P = 0.005), and Forgotten Joint Scores (65.4 versus 53.8; P < 0.001).

CONCLUSIONS

As more time passes after TKA, patients observe less prosthetic noise generation and have lower levels of prosthesis awareness and greater satisfaction than those who had surgery more recently. It is unclear whether these differences represent real improvement or acclimation to noise over time.

The Needs and Experiences of Patients Returning to Work After Total Knee Arthroplasty and Total Hip Arthroplasty: A Systematic Review and Meta-Synthesis

OBJECTIVE

The objective of this study was to conduct a systematic and comprehensive review of qualitative research to examine the physical and psychological needs, as well as work experiences, of patients undergoing total knee replacement and total hip replacement surgeries during their process of returning to work.

METHODS

A systematic review and meta-synthesis of qualitative literature was conducted. A systematic search was conducted across 8 databases to identify qualitative or mixed-methods research on the needs and experiences of individuals with total knee replacement and total hip replacement who have returned to work. The search period extended from the inception of each database to March 2023. Two researchers independently utilized a predetermined search strategy to retrieve relevant English-language studies published in any year. The included studies were assessed for quality using the Critical Appraisal Skills Program appraisal tool. Findings from the studies were then summarized and integrated using the pooled integration method.

RESULTS

There were 10 studies in total. Three key themes were identified from the original research: needs during the return to work process and rehabilitation training, faith and support to return to work, and constraints and challenges at work.

CONCLUSION

Health care professionals and employers should conscientiously consider the physical and psychological requirements of patients who have undergone total knee replacement and total hip replacement when they are resuming work, taking into account the specific constraints and challenges that may arise in the workplace. To ensure a seamless transition back to work, it is essential to develop tailored occupational interventions, implement comprehensive return to work programs, and offer patients sufficient understanding and support.

IMPACT

The findings of this study offer valuable insights into the physical and psychological needs, as well as the work experiences, of patients who have undergone total knee replacement and total hip replacement during their reintegration into the workforce. These findings have the potential to assist health care professionals and employers in providing enhanced support to facilitate successful return-to-work outcomes for patients.

Analysis of the causes of primary revision after unicompartmental knee arthroplasty: A case series

BACKGROUND

Unicompartmental knee arthroplasty (UKA) has great advantages in the treatment of unicompartmental knee osteoarthritis, but its revision rate is higher than that of total knee arthroplasty.

AIM

To summarize and analyse the causes of revision after UKA.

METHODS

This is a retrospective case series study in which the reasons for the first revision after UKA are summarized. We analysed the clinical symptoms, medical histories, laboratory test results, imaging examination results and treatment processes of the patients who underwent revision and summarized the reasons for primary revision after UKA.

RESULTS

A total of 13 patients, including 3 males and 10 females, underwent revision surgery after UKA. The average age of the included patients was 67.62 years. The prosthesis was used for 3 d to 72 months. The main reasons for revision after UKA were improper suturing of the surgical opening (1 patient), osteophytes (2 patients), intra-articular loose bodies (2 patients), tibial prosthesis loosening (2 patients), rheumatoid arthritis (1 patient), gasket dislocation (3 patients), anterior cruciate ligament injury (1 patient), and medial collateral ligament injury with residual bone cement (1 patient).

CONCLUSION

The causes of primary revision after UKA were gasket dislocation, osteophytes, intra-articular loose bodies and tibial prosthesis loosening. Avoidance of these factors may greatly reduce the rate of revision after UKA, improve patient satisfaction and reduce medical burden.

[Functional outcomes and return to sports, work, and daily activities after revision UKA compared to primary UKA and TKA]

BACKGROUND

Unicompartmental knee arthroplasty (UKA), in addition to total knee arthroplasty (TKA), has been shown to be effective in the surgical treatment of knee osteoarthritis with appropriate patient selection. In clinical studies, it has demonstrated superior functional results with lower complication rates. In clinical practice, these advantages must be weighed against the disadvantage of an increased revision rate, especially in younger patients with sports and work activities.

OBJECTIVES

The aim of this study was to compare the functional outcome as well as the time to return to daily activities, work, and sports after revision of UKA to TKA with those of primary UKA and primary TKA using a matched-pair analysis.

MATERIALS AND METHODS

The study was based on a matched-pair analysis at two defined time points, always comparing 28 patients who underwent either revision of a UKA to a TKA, primary UKA, or primary TKA. Patients completed the Oxford Knee Score, UCLA score, Knee Society score, and WOMAC score during standardized follow-up. In addition, postoperative patient satisfaction and return to activities of daily living, work, and sports were recorded in a standardized manner, and a clinical examination was performed.

RESULTS

The four functional scores studied showed a common trend in favor of UKA, followed by primary TKA and revision TKA. The differences between converted UKA and primary TKA were not significant. However, at 3.2 years after the last surgery, the results of the converted UKA were significantly lower than those of the primary UKA. Return to work and sports tended to occur the earliest after UKA, followed by TKA and the revision group. All groups showed a tendency to engage in low-impact sports.

CONCLUSION

The functional results of revised UKA were significantly inferior to those of primary UKA based on a 3-year follow-up. Return to work, sports, and activities of daily living tended to take longer after revision than after primary implantation of either a UKA or a TKA.

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.

Return to work and employment retention after uni-compartmental and total knee replacement: findings from the Clinical Outcomes in Arthroplasty study

BACKGROUND

Little is known about ability to work after unicompartmental knee replacement (UKR) and total knee replacement (TKR), especially in physically-demanding occupations. This study described rates of return-to-work (RTW) and ability to sustain work by job after arthroplasty.

METHOD

Participants from The Clinical Outcomes in Arthroplasty Study (COASt) aged 18-65 were eligible if they underwent UKR or TKR and had at least 5 years' follow-up post-operation. We posted a survey asking about pre-operative occupation, post-operative occupations and associated physical demands, and whether they had quit a job post-surgery due to difficulties with the operated knee (knee-related job loss (KRJL)). We fitted Cox Proportional Hazard Models to investigate the role of demanding physical activities on KRJL.

RESULTS

251 people (143 UKR, 108 TKR) returned a questionnaire, of whom 101 UKR and 57 TKR worked post-operatively. Rates of RTW were highest amongst those in managerial and professional or technical roles, whichever operation they received. RTW was poorest amongst those in elementary occupations. In associate professional/technical occupations, RTW rates were better amongst UKR recipients. Amongst participants who returned to work, 17 reported KRJL (8.5% UKR and 16.7% TKR). Respondents were more likely to have KRJL if their job involved carrying/lifting ≥10 kg (HR:4.81, 95%CI 1.55-14.93) or climbing >30 flights of stairs (HR:4.03, 95%CI 1.36-11.98).

CONCLUSIONS

Knee arthroplasty recipients working pre-operatively mostly RTW. RTW may be more difficult after TKR than UKR. Jobs which involve lifting and climbing stairs may be particularly challenging. Surgeons offering knee arthroplasty should counsel patients about workability as well as risk of revision.

Return to Sport and Work after Randomization for Knee Distraction versus High Tibial Osteotomy: Is There a Difference?

Knee joint distraction (KJD) is a novel technique for relatively young knee osteoarthritis (OA) patients. With KJD, an external distraction device creates temporary total absence of contact between cartilage surfaces, which results in pain relief and possibly limits the progression of knee OA. Recently, KJD showed similar clinical outcomes compared with high tibial osteotomy (HTO). Yet, no comparative data exist regarding return to sport (RTS) and return to work (RTW) after KJD. Therefore, our aim was to compare RTS and RTW between KJD and HTO. We performed a cross-sectional follow-up study in patients <65 years who previously participated in a randomized controlled trial comparing KJD and HTO. Out of 62 eligible patients, 55 patients responded and 51 completed the questionnaire (16 KJDs and 35 HTOs) at 5-year follow-up. The primary outcome measures were the percentages of RTS and RTW. Secondary outcome measures included time to RTS/RTW, and pre- and postoperative Tegner's (higher is more active), and Work Osteoarthritis or Joint-Replacement Questionnaire (WORQ) scores (higher is better work ability). Patients' baseline characteristics did not differ. Total 1 year after KJD, 79% returned to sport versus 80% after HTO (not significant [n.s.]). RTS <6 months was 73 and 75%, respectively (n.s.). RTW 1 year after KJD was 94 versus 97% after HTO (n.s.), and 91 versus 87% <6 months (n.s.). The median Tegner's score decreased from 5.0 to 3.5 after KJD, and from 5.0 to 3.0 after HTO (n.s.). The mean WORQ score improvement was higher after HTO (16 ± 16) than after KJD (6 ± 13; p = 0.04). Thus, no differences were found for sport and work participation between KJD and HTO in our small, though first ever, cohort. Overall, these findings may support further investigation into KJD as a possible joint-preserving option for challenging "young" knee OA patients. The level of evidence is III.

Impact of keel saw blade design and thickness on the incidence of tibial plateau fracture and tibial implant-loosening in cementless medial UKR

BACKGROUND

Tibial plateau fractures and tibial implant- loosening are severe complications in cementless unicompartmental knee replacement (UKR). The tibial keel preparation is particularly demanding and different saw blades can be used. It was hypothesized that different blade designs and thickness have an influence on the frequency of tibial plateau fractures and implant-loosening in cementless medial UKR.

METHODS

1258 patients with cementless medial UKR were included in this retrospective study between 2013 and 2020. The tibial keel cut was performed either with a double keel saw blade (DKS; 2.8 mm) and added hand guided pick or a mono reciprocating saw blade (RKB) of different thickness (2.5 mm; 2.65 mm; 2.75 mm). Tibial plateau fracture and loosening were demonstrated by standard two-plane radiographs. Tibial implant-loosening was defined as complete radiolucency and implant migration. Fracture and loosening were combined with pain and loss of function.

RESULTS

In 126 patients (10%) the tibial keel was prepared with DKS, in 407 patients (32.4%) with RKB 2.5 mm, in 330 patients (26.2%) with RKB 2.65 mm and in 395 patients (31.4%) with 2.75 mm. In 4 patients (3.17%) with DKS tibial plateau fracture occurred, in 4 patients (0.99%) with 2.5 mm RKB, in 3 patients (0.92%) with 2.65 mm RKB and in 1 patient (0.25%) with 2.75 mm RKB. Significantly fewer fractures occurred with a RKB design (p = 0.007). A negative correlation between fracture incidence and RKB saw blade thickness was found (Spearman-r = - 0.93). No difference for tibial implant-loosening was shown (p = 0.51).

CONCLUSION

Different blade designs and thickness have a significant influence on the incidence of tibial plateau fractures and aseptic tibial implant-loosening. The incidence of tibial plateau fractures in cementless medial UKR can be reduced by changing the design and thickness of the tibial keel saw blade. Greater thickness of RKB leads to significantly fewer tibial plateau fractures while the incidence of implant-loosening is not increasing.

TRIAL REGISTRATION

This study was retrospectively registered and ethical approval was waived by the local ethical committee (No. 2020-1174).

Large variability in recommendations for return to daily life activities after knee arthroplasty among Dutch hospitals and clinics: a cross-sectional study

BACKGROUND AND PURPOSE

Recommendations concerning the return to daily life activities, including work and sport, after knee arthroplasty (KA) are essential for setting realistic patient expectations. Fulfillment of these expectations contributes to more satisfaction and enhanced recovery after KA. However, scientific evidence for such recommendations is limited, and recommendations are often based only on healthcare professionals' expert opinions. We summarized the current recommendations regarding return to daily life activities provided by Dutch hospitals and clinics to KA patients.

MATERIAL AND METHODS

Recommendations of 43 Dutch hospitals and clinics were identified, representing the advice provided to 70% of the total Dutch KA patients. Recommendations were retrieved from content from websites (n = 8), brochures (n = 40), and mobile phone applications (n = 9).

RESULTS

Recommendations for 24 daily life activities were identified. Individual hospitals and clinics provided recommendations for, on average, 9 (0-15) of these activities. Recommendations varied greatly. For example, recommendations regarding when to resume cycling after KA were provided by 36 of the 43 hospitals and clinics and varied from 3 weeks to 3 months.

INTERPRETATION

Recommendations for return to daily life activities are often missing and vary considerably between Dutch hospitals and clinics. These findings show the need for more uniformity across healthcare providers regarding recommendations for postoperative return to daily life activities.

A Comparative Study of Total Knee Arthroplasty and Unicondylar Knee Arthroplasty in the Treatment of Knee Osteoarthritis

Objective

To compare the clinical efficacy of total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA) in the treatment of knee osteoarthritis (KOA).

Methods

A retrospective analysis was conducted on 30 patients admitted to the Department of Orthopaedics of Yijishan Hospital from 2020 to 2021. The patients were divided into UKA group (n = 15) and TKA group (control, n = 15). The intraoperative situation and postoperative clinical indicators of patients in the two groups were collected and compared, such as operation time, intraoperative blood loss, length of hospital stay, postoperative complications, and postoperative functional recovery. Postoperative functional recovery was investigated by the visual analogue pain scale (VAS), knee score scale (HSS), and knee range of motion (ROM) scores 5 days after surgery.

Results

Perioperative indexes in the UKA group were significantly lower than those in the TKA group, including operation time, intraoperative blood loss, first time going to the ground, and length of hospital stay. VAS, HSS, and ROM scores in the two groups were significantly improved after surgery compared with those before surgery. However, ROM scores in the UKA group were significantly better than in the TKA group. In terms of early postoperative complications, there was one case of venous thrombosis of lower limbs in the UKA group, while in the TKA group there was one case of delayed wound healing due to diabetes, and one case of deep infection.

Conclusion

Both UKA and TKA are very successful options for the treatment of KOA, but the use of UKA can promote the recovery of postoperative knee function, reduce postoperative complications, and achieve more satisfactory than expected results.

Health screening questionnaires used in the management of mental distress acquired during an injured worker’s return to work: A scoping review

BACKGROUND: Mental distress is often endured by injured workers participating in the rehabilitation or return to work process following a physical injury. Delays in detecting the onset and treating mental distress can lead to a diverse range of cognitive and behavioural changes that may precipitate psychological distress such as anxiety, depression, and posttraumatic stress. OBJECTIVE: The objective of this scoping review was to provide an overview of existing health questionnaires utilised by health care providers and affiliated researchers. It reviewed their effectiveness and suitability to detect mental distress endured by injured workers engaged in the return to work process. METHODS: A scoping review methodology was conducted using the Arksey and O’Malley framework which examined peer-reviewed articles published between 2000 and March 2020 comprising health questionnaires. Database searches included Medline, CINAHL, EMBASE and PsycINFO combining specific MeSH terms and key words. RESULTS: The full search identified 3168 articles. Following full screening a total of 164 articles reviewed the use of health questionnaires and specific criteria to determine their suitability. Most of the health questionnaires reviewed were used as screening measures for identifying both work and non-work-related psychological hazards. However, they were found to be limited in their application when considering all potential predictors of delayed return to work such as poor or stressful interactions with stakeholders, financial stress and the injured workers experience of the RTW process. CONCLUSION: Earlier identification of mental distress using an optimal MHSQ followed by appropriate intervention will reduce the risk of psychological injury becoming cumulative on a physical workplace injury. Without such complications, early return to work can be achieved with significant cost saving to the economy.

Knee Scores of Patients with Non-Lateral Compartmental Knee Osteoarthritis Undergoing Mobile, Fixed-Bearing Unicompartmental Knee and Total Knee Arthroplasties: A Randomized Controlled Trial

Objective

To evaluate knee scores and clinical efficacies of patients with non‐lateral unicompartmental knee osteoarthritis (OA) who randomly underwent mobile‐bearing (MB) unicompartmental knee arthroplasty (UKA), fixed‐bearing (FB) UKA, and total knee arthroplasty (TKA).

Methods

From September 2015 to February 2017, a prospective, randomized, parallel, single‐center trial of 180 patients (78 males and 102 females; 63.3 ± 6.9 years) with non‐lateral compartmental knee OA was performed in the first author‐affiliated hospital. The patients were randomly divided into three groups (each group included 60 patients) and received medial cemented Oxford phase 3 MB UKA, medial cemented Link FB UKA, or cemented DePuy Sigma PFC TKA, respectively. A similar perioperative management and fast‐track surgery program was carried out for all patients. The knee scores at 3‐year follow‐up after operation and clinical efficacies of these three groups of patients were recorded, investigated, and compared.

Results

Primarily, compared to the TKA group, the UKA groups (MB UKA and FB UKA) had shorter operative time (median 63.2 < 67.1 min), less bleeding (8.6 < 30.0 mL), earlier resumption of walking without crutches (3.0 < 8.0 days) and walking up and down the stairs (5.0 < 10.0 days) (P < 0.001), higher FJS scores (78.0 > 74.5) (P = 0.007), better results in all knee scores (except VAS and KSS function scores) (P < 0.05), and a larger maximum flexion angle of the knee at the 3‐year follow‐up (123.0° > 96.0°) (P = 0.001). Secondarily, compared to the TKA group, the MB UKA group showed better results in the Western Ontario and McMaster Universities index (WOMAC) stiffness (83.6 > 79.6), WOMAC total (86.3 > 83.2), Oxford knee score (OKS) (20.0 < 23.0), Forgotten Joint Score (FJS) (78.5 > 74.5), and a larger maximum flexion angle of the knee (123.0 > 96.0) (P < 0.05). Moreover, the FB UKA group showed higher Hospital for Special Surgery Knee Score (HSS) (91.0 > 88.5), WOMAC stiffness (84.3 > 79.6), WOMAC function (85.2 > 81.7), WOMAC total scores (87.6 > 83.2), and a larger maximum flexion angle of the knee (119.0° > 96.0°) than the TKA group (P < 0.05). Overall, there was no significant difference in all knee scores and maximum flexion angles of the knee for the MB UKA and FB UKA groups (P > 0.05). There was one case with original bearing dislocation in MB UKA group. One patient with displacement of the femoral component caused by a fall injury, and another patient, who lost his life in a car accident, were involved in the FB UKA group. There was an infection case and an intermuscular vein thrombosis case in TKA group.

Conclusion

UKA showed more advantages than TKA; however, there was no significant difference between the MB UKA and FB UKA groups for treatment of non‐lateral compartmental knee OA.

A Weighted Scoring System Based on Preoperative and Long-Term Patient-Reported Outcome Measures to Guide Timing of Knee Arthroplasty

BACKGROUND

There is currently no existing consensus regarding timing of knee arthroplasty. This study aimed to develop a weighted scoring system from patient-reported outcome measures (PROMs) to guide timing of knee arthroplasty based on preoperative severity and long-term effectiveness.

METHODS

Prospectively collected data of 766 total knee arthroplasties (TKAs) and 382 unicompartmental knee arthroplasties (UKAs) at a single institution were analyzed. PROMs were assessed preoperatively and at 10 years using the Knee Society Score (KSS), Oxford Knee Score (OKS), and Short Form-36 physical component score (SF-36 PCS). Receiver operating characteristic analysis identified thresholds where preoperative PROMs predicted 10-year clinically meaningful improvements (minimal clinically important difference [MCID]). Threshold weights were assigned to PROMs based on their ability to predict MCID in isolation or in combination.

RESULTS

Poorer baseline PROMs predicted 10-year MCID attainments. The threshold of 49.5 points for the KSS, 30.5 points for the OKS, and 40.7 points for the SF-36 PCS and 55.5 points for the KSS, 33.5 points for the OKS, and 40.5 points for the SF-36 PCS was weighted 1 point for predicting MCID in 1 PROM for TKA and UKA, respectively. The threshold of 33.4 and 33.9 points for the SF-36 PCS was weighted 2 points for predicting MCID in 2 PROMs, whereas 29.3 and 31.3 points for the SF-36 PCS were weighted 3 points for predicting MCID in 3 PROMs for TKA and UKA, respectively. The sum of weighted components from 0 (lowest) to 5 (highest) represented likelihood for long-term benefits at 10 years.

CONCLUSION

This scoring system is a useful clinical adjunct for deciding timing of knee arthroplasty and prioritizing patients in institutions with long waitlists.

LEVEL OF EVIDENCE

II.

Total and unicondylar knee arthroplasty are equivalent treatment options in end-stage spontaneous osteonecrosis of the knee, and the size of the lesion has no influence on the results

PURPOSE

The purpose of the present study was to compare total (TKA) and unicondylar (UKA) knee arthroplasty for spontaneous osteonecrosis of the knee (SONK), and to investigate potential correlations to radiographic parameters.

METHODS

All consecutive patients with a magnetic resonance imaging (MRI) proven SONK treated with either TKA or UKA between 2002 and 2018 were analysed. The primary outcomes were postoperative complications and failure rates. Functional assessment included Knee Society Score (KSS), WOMAC Score, and range of motion. A novel three-dimensional measurement method was established to determine the size of the osteonecrotic lesion. All outcome parameters were correlated to the size of the necrotic lesion using Spearman's rank correlation.

RESULTS

The two treatment groups (34 TKAs, 37 UKAs) did not differ regarding age, body mass index, and ratio of the volume of the necrotic lesion to the volume of the femoral condyle (n.s.). At a mean follow-up of 6.6 years, patients with UKA had better functional outcomes compared to patients with a TKA (WOMAC Score 1.0 vs. 1.6, p = 0.04; KSS pain 86 vs. 83, n.s), with a similar complication rate. No correlation was found between necrotic lesion size and failure rate (n.s.).

CONCLUSION

UKA is a valuable treatment option for SONK leading to good functional results and a low failure rate. In case of a surgeon's concern regarding implant anchorage, TKA represents an equivalent solution. The MR-tomographic size of the osteonecrotic lesions seems to have no influence on the results.

LEVEL OF EVIDENCE

III.

Return to physical activity and change in body mass index after hypoallergenic medial mobile-bearing unicompartmental knee arthroplasty

Background

The primary purpose of the present prospective study was to consecutively analyse the outcomes of the return to sports activity of patients with positive patch tests undergoing a medial mobile-bearing titanium niobium nitride (TiNbN) unicompartmental knee arthroplasty (UKA). The secondary purpose was to ascertain if a higher grade of physical activity leads to a reduction in the body mass index (BMI) of the patients.

Material and methods

Forty-one patients with positive skin patch tests were included in this prospective study. The clinical evaluation consisted of the University of California, Los Angeles (UCLA) activity scale and the High-Activity Arthroplasty Score (HAAS). Each patient was evaluated the day before surgery (T₀), after 12.37 ± 0.70 months (T₁), and on the day of the final follow-up, after 67.03 ± 18.2 months (T₂). Furthermore, the BMI of each patient was analysed before surgery and during the final follow-up.

Results

The UCLA and HAAS mean preoperative values ranged from 3.68 ± 1.1.7 and 6.15 ± 0.76 to 6.1 ± 0.76 and 10.34 ± 1.3, respectively, at T₁ (p < 0.0001) and to the final values of 6.34 ± 0.62 and 11.0 ± 8.9, respectively, at T₂ (UCLA: T₂ versus T₁: p = 0.132; T₂ versus T₀: p < 0.0001; HAAS: T₂ versus T₁: p = 0.0027; T₂ versus T₀: p < 0.001). BMI ranged from a preoperative value of 27.97 ± 3.63 to a final value of 26.84 ± 3.11 (p < 0.0001). The only differences within the subgroups concerned patients with BMI ≥ 28, showing a superior HAAS at each follow-up (p < 0.05). A positive correlation was found between BMI and HAAS at T₀ and T₂ (p < 0.05).

Conclusions

This is the first study to evaluate the rate of the return to sports activities and change in BMI following hypoallergenic UKA. The majority of patients reduced their weight following UKA and improved their physical activity, showing outcomes that were comparable to the standard cobalt–chrome (CoCr) prostheses, regardless of gender, age, BMI and implant size.

Level of evidence

IV – Prospective Cohort Study.

Trial registration researchregistry5978—Research Registry www.researchregistry.com

Supplementary Information

The online version contains supplementary material available at 10.1186/s10195-021-00598-4.

Costs of unicompartmental compared with total knee arthroplasty : a matched cohort study over ten years

AIMS

The aim of this study was to compare ten-year longitudinal healthcare costs and revision rates for patients undergoing unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA).

METHODS

The Humana database was used to compare 2,383 patients undergoing UKA between 2007 and 2009, who were matched 1:1 from a cohort of 63,036 patients undergoing primary TKA based on age, sex, and Elixhauser Comorbidity Index. Medical and surgical complications were tracked longitudinally for one year following surgery. Rates of revision surgery and cumulative mean healthcare costs were recorded for this period of time and compared between the cohorts.

RESULTS

Patients undergoing TKA had significantly higher rates of manipulation under anaesthesia (3.9% vs 0.9%; p < 0.001), deep vein thrombosis (5.0% vs 3.1%; p < 0.001), pulmonary embolism (1.5% vs 0.8%; p = 0.001), and renal failure (4.2% vs 2.2%; p < 0.001). Revision rates, however, were significantly higher for UKA at five years (6.0% vs 4.2%; p = 0.007) and ten years postoperatively (6.5% vs 4.4%; p = 0.002). Longitudinal-related healthcare costs for patients undergoing TKA were greater than for those undergoing UKA at one year ($24,771 vs $22,071; p < 0.001) and five years following surgery ($26,549 vs $25,730; p < 0.001); however, the mean costs of TKA were comparable to UKA at ten years ($26,877 vs $26,891; p = 0.425).

CONCLUSION

Despite higher revision rates, patients undergoing UKA had lower mean healthcare costs than those undergoing TKA up to ten years following the procedure, at which time costs were comparable. In the era of value-based care, surgeons and policymakers should be aware of the costs involved with these procedures. UKA was associated with fewer complications at one year postoperatively but higher revision rates at five and ten years. While UKA was significantly less costly than TKA at one and five years, costs at ten years were comparable with a mean difference of only $14. Lowering the risk of revision surgery should be targeted as a source of cost savings for both UKA and TKA as the mean related healthcare costs were 2.5-fold higher in patients requiring revision surgery. Cite this article: Bone Joint J 2021;103-B(6 Supple A):23-31.

Return to work after medial unicompartmental knee arthroplasty: A systematic review

INTRODUCTION

This study aims to evaluate the current literature with regard to the average time to and overall rate of return to work (RTW) following medial unicompartmental knee arthroplasty (UKA).

METHODS

A systematic search was conducted on MEDLINE (Ovid), Embase, Pubmed, CINAHL, Web of Science, Scopus, and the Cochrane Library to identify studies reporting RTW after UKA. Primary outcomes were the rate and time to RTW after UKA. Secondary outcomes were postoperative changes in work intensity, functional scores, and factors affecting RTW. Methodological quality was evaluated using the the Methodological Index for Non-Randomized Studies (MINORS) criteria.

RESULTS

Seven studies met inclusion criteria. Results were summarized qualitatively. The overall methodological quality of the studies was moderate based on the MINORS score. These studies included 636 patients with 46.5% male. Mean age was 63.1 years. The average rate of RTW was 81.7%. The average time to RTW was 5.4 ± 3.9 weeks (range 1-32 weeks). 81.8% of patients in one study returned to an equally or more physically demanding job, while 83.5% were able to work the same or longer hours postoperatively in another study. Functional scores improved after surgery (n = 6 studies). Factors affecting RTW were postoperative rehabilitation, retirement, and the effects of surgery.

CONCLUSION

Limited evidence from the included studies with moderate quality suggests that UKA allows patients to RTW faster, with a high rate of RTW and improved functional outcomes. However, consensus definitions and methods of work status analysis are needed for future studies.

Return to sports after medial unicompartmental knee arthroplasty in patients with concomitant patella-femoral osteoarthritis: multicenter retrospective cohort study with minimum 5-year follow-up

PURPOSE

The purpose of our study was to evaluate clinical outcomes and return to sports after medial unicompartmental knee arthroplasty (UKA) in middle-aged active patients with concomitant patella-femoral joint (PFJ) osteoarthritis at time of surgery.

METHODS

One-hundred and fifty-one patients who underwent medial fixed-bearing cemented UKA, between 2012 and 2015, for medial unicompartmental osteoarthritis of the knee, were retrospectively reviewed with a minimum 5-year follow-up. The mean age at surgery was 54.3 years (range 47 to 60 years). Radiological evaluation of patella-femoral joint (PFJ) osteoarthritis was performed according to Sperner classification to select a control-group (< grade III) and case-group (≥ grade III). The visual analog scale (VAS) for pain and Knee Society score (KSS) was used to evaluate preoperative and final outcomes. Physical activity level before and after the surgery was assessed by the use of UCLA score.

RESULTS

One-hundred and thirty-seven patients (89 males and 48 females) were available at last follow-up. The mean follow-up was 6.2 years (range 5.2 to 7.5 years). At last follow-up improvements of VAS and KSS scores revealed not significant correlation with PFJ osteoarthritis. The majority of patients (87.7%) returned to their sports activity after UKA surgery.

CONCLUSIONS

Improved quality of life and sports activity level resulted in middle-aged, active patients after UKAs. PFJ osteoarthritis showed no significant correlation with poorer outcomes at 5-year follow-up.

LEVEL OF EVIDENCE

III, multicenter retrospective cohort study.

The projected volume of primary and revision total knee arthroplasty will place an immense burden on future health care systems over the next 30 years

PURPOSE

Total knee arthroplasty (TKA) rates have increased substantially in the recent decades worldwide, with Germany being one of the leading countries in the prevalence of TKA. The aim of this study was to provide an overview of treatment changes during the last decade and to project the expected burden of primary and revision TKA (rTKA) for the next 30 years.

METHODS

Comprehensive nationwide data from Germany was used to quantify primary and revision TKA rates as a function of age and gender. Projections were performed with use of a Poisson regression models and a combination of exponential smoothing and autoregressive integrated moving average models on historical procedure rates in relation to official population projections from 2020 to 2050.

RESULTS

The incidence rate of primary TKAs is projected to increase by around 43% to 299 per 100,000 inhabitants [95% CI 231-368], leading to a projected total number of 225,957 primary TKAs in 2050 (95% CI 178,804-276,442). This increase has been related to a growing number of TKA performed in male patients, with the highest increase modelled in patients between 50 and 65 years of age. At the same time, the annual total number of revision procedures is forecast to increase even more rapidly by almost 90%, accounting for 47,313 (95% CI 15,741-78,885; IR = 62.7 per 100,000, 95% CI 20.8-104.5) procedures by 2050. Those numbers are primarily associated with a rising number of rTKAs secondary to periprosthetic joint infection (PJI).

CONCLUSIONS

Using this country- specific forecast approach, a rising number of primary TKA and an even more rapidly growing number of rTKA, especially for PJI, has been projected until 2050, which will inevitably provide a huge challenge for the future health care system. As many other industrialized nations will face similar demographic and procedure-specific developments, these forecasts should be alarming for many health care systems worldwide and emphasize the tremendous need for an appropriate financial and human resource management in the future.

LEVEL OF EVIDENCE

Level III, prognostic study, economic and decision analysis.

Lifetime revision risk for medial unicompartmental knee replacement is lower than expected

PURPOSE

Unicompartmental knee replacement (UKR) is widely considered to be a pre-total knee replacement (TKR) particularly in the young. The implication of this is that it is sensible to do a UKR, even though it will be revised at some stage, as it will delay the need for a TKR. The chance of a UKR being revised during a patient's life time has not previously been calculated. The aim of this study was to estimate this lifetime revision risks for patients of different ages undergoing UKR.

METHODS

Calculations were based on data from a designer series of 1000 medial Oxford UKR with mean 10-year follow up. These UKR were implanted for the recommended indications using the recommended surgical technique. Parametric survival models were developed for patients of different ages based on observed data, and were extrapolated using a Markov model to estimate lifetime revision risk.

RESULTS

The estimated lifetime revision risk reduced with increasing age at surgery. Lifetime revision risk at age 55 was 15% (95% CI 12-19), at 65 it was 11% (8-13), at 75 it was 7% (5-9), and at 85 it was 4% (3-5).

CONCLUSION

Provided UKR is used appropriately, the lifetime revision risk is markedly lower than expected. UKR should be considered to be a definitive knee replacement rather than a Pre-TKR even in the young. These lifetime estimates, alongside established benefits for UKR in speed of recovery, morbidity, mortality and function, can be discussed with appropriate patients when considering whether to implant a UKR or TKR.

LEVEL OF EVIDENCE

III.

Development of a Personalized m/eHealth Algorithm for the Resumption of Activities of Daily Life Including Work and Sport after Total and Unicompartmental Knee Arthroplasty: A Multidisciplinary Delphi Study

Evidence for recommendations concerning the resumption of activities of daily life, including work and sport, after knee arthroplasty is lacking. Therefore, recommendations vary considerably between hospitals and healthcare professionals. We aimed to obtain multidisciplinary consensus for such recommendations. Using a Delphi procedure, we strived to reach consensus among a multidisciplinary expert panel of six orthopaedic surgeons, three physical therapists, five occupational physicians and one physician assistant on recommendations regarding the resumption of 27 activities of daily life. The Delphi procedure involved three online questionnaire rounds and one face-to-face consensus meeting. In each of these four rounds, experts independently decided at what time daily life activities could feasibly and safely be resumed after knee arthroplasty. We distinguished patients with a fast, average and slow recovery. After four Delphi rounds, the expert panel reached consensus for all 27 activities. For example, experts agreed that total knee arthroplasty patients with a fast recovery could resume cycling six weeks after the surgery, while those with an average and slow recovery could resume this activity after nine and twelve weeks, respectively. The consensus recommendations will subsequently be integrated into an algorithm of a personalized m/eHealth portal to enhance recovery among knee arthroplasty patients.