Introduction

Knee replacement surgery is recommended for patients whose quality of life has declined because of degenerative joint issues disease¹. The percentage of patients dissatisfied with the outcomes of total knee arthroplasty (TKA) ranges from 8% to 27%². In recent years, a cultural shift within the medical, technological, technical-surgical, and evaluative fields has emphasized the importance of focusing the therapeutic strategy around the patient in knee arthroplasty procedures^3-13. The concept of “personalization” embodies this paradigm shift, aiming to improve both outcomes and patient satisfaction following TKA. A Personalized Diagnostic-Therapeutic Pathway (PDTP) is grounded in adherence to fast track/Enhanced Recovery After Surgery (ERAS) protocols, the application of new alignment philosophies respecting patient phenotypes¹⁴, the use of computer/robot-assisted technologies, and the assessment of outcomes using Patient-Reported Outcome Measures (PROMs). PROMs evaluate everyday life by directly involving patients, highlighting the significance of their perspectives^4,15-17.  Numerous PROMs are cited in the literature, each exploring clinical, functional, and psychosocial aspects in various ways. An analysis of the domains and questions included in commonly used PROMs reveals a certain level of complexity, difficulty in comprehension, and unintuitive methods for calculating results^18,19.

To simplify the approach to PROMs for collecting postoperative results, a straightforward questionnaire was prepared that included direct questions to assess patients’ satisfaction with the overall outcome of knee prosthesis surgery. This allowed for a percentage value to be assigned to the degree of satisfaction expressed directly by the patients. Therefore, since this was the main goal of the study, an examination was conducted to determine which clinical and functional parameters significantly influence the reported satisfaction and whether this could be affected by the type of surgical protocol used.

Subjects and Methods

The results of knee prosthesis surgeries performed between 2017 and 2020 were retrospectively evaluated after obtaining the approval of the CEROM (Ethical Committee of Romagna), with determination No. 1590 on May 22, 2023.
For this study, 88 patients were selected, including 29 males and 59 females, aged between 36 and 84 years (Table 1).

Table 1. Demographic data.

Inclusion criteria: all patients underwent surgery due to severe impairment of quality of life and near-constant pain with a Numeric Rating Scale (NRS) value greater than 8. A preoperative pathway was organized for all patients, which always included anesthetic consultation and weight-bearing radiographs of the lower limbs (X-ray of the pelvis and entire lower limbs under weight-bearing conditions; X-ray of the knees in Rosenberg view with bilateral weight-bearing) according to the protocol shared with the Radiology Department of G.B. Morgagni Hospital in Forlì. All surgeries were conducted by the same surgeon. Patients were selected if they were treated with the same model, posterior stabilized (PS), and all prostheses were cemented.

Exclusion criteria: during the study period, all patients operated on by the manuscript’s author received posterior-stabilized (PS) cemented knee prostheses, predominantly from a specific brand. Patients who received prostheses from other manufacturers – represented by a limited number of cases – were excluded from the evaluation. In the 2017-2018 period, 44 cemented PS prostheses were implanted without employing Fast Track/Enhanced Recovery After Surgery (ERAS) protocols or personalized surgical technique concepts, aiming for mechanical alignment. In the 2019-2020 period, another 44 cemented PS prostheses were implanted, following fast-track/ERAS protocols and personalized surgical techniques, targeting constitutional/functional alignment. A study protocol was developed to include not only the evaluation of clinical records but also an administered questionnaire designed to be easily comprehensible. The questionnaire included questions related to pain, function, and postoperative satisfaction. This protocol was approved by the CEROM Ethics Committee. The questionnaire consisted of 14 items divided into three main domains (Table 2):

Clinical outcomes: This domain included five questions that primarily retrospectively investigated the clinical parameter of pain. Patients were asked whether they experienced pain in other joints, if they continued to have pain in the operated knee, to quantify their pain using the NRS, and whether they experienced pain at rest and during the night.
Functional outcomes: This domain consisted of seven questions evaluating functional aspects. Patients were asked about difficulties in getting out of bed or a chair, their ability to climb stairs, ride a bicycle, assess the movement of the operated knee, perform usual daily activities, and whether they had regained strength in the operated limb.
Subjective outcomes: This domain included only two questions. One specifically investigated the patients’ satisfaction with the results obtained, while the second question asked if they would undergo the surgery again, indirectly confirming their satisfaction.

Table 2. Questionnaire: three main domains and 14 items.

Data Analysis

Descriptive statistical analysis was performed on all responses to the questionnaire items. Statistics were calculated overall and separately for each year, with all estimates accompanied by a 95% confidence interval. The association or correlation of various factors with outcomes (clinical, functional, and subjective) was assessed using the Chi-square test or non-parametric rank tests (Mann-Whitney test, Kruskal-Wallis test, Spearman’s test), depending on the nature of the variable under study. Overall satisfaction (a dichotomous variable) was utilized as the outcome (y) in a multivariate logistic regression model, incorporating factors (x) found to be significant in univariate analysis, in order to evaluate the adjusted weight of each factor. A significance threshold of 0.05 was applied for all tests. Analyses were conducted using STATA 17.0 software (College Station, TX, USA).

Results

Table 3 presents the percentages of positive responses to the questionnaire items. The percentage of satisfied patients who would undergo the procedure again was very high, with 94% positive responses to questions 13 and 14 of the questionnaire. Table 4 presents odds ratios indicating the association between patient dissatisfaction and the clinical and functional outcomes included in the questionnaire. Odds greater than 1 indicate that the outcome increases patient dissatisfaction with the prosthesis result of the surgery. Conversely, odds less than 1 suggest an improvement in patient dissatisfaction. Neutral odds equal to 1 do not affect patient dissatisfaction. The presence of other painful joints and nighttime pain in the operated knee was associated with lower patient satisfaction. Conversely, the ability to ride a bicycle, move the knee well, and regain strength positively influenced their satisfaction (Table 4).  No statistically significant correlations were observed between any of the clinical and functional parameters included in the questionnaire and a personalized surgical approach.

Table 3. Percentage of responses to the 14 questions of the questionnaire.

Discussion

Patients undergoing knee prosthesis surgery aim to improve their quality of life. Quality of life reflects personal well-being, shaped by physical health (good function, absence of symptoms), psychological well-being (emotional health, no anxiety or depression, full cognitive ability), and social factors (feeling autonomous and independent). These aspects are often interconnected. Patients suffering from chronic degenerative joint diseases experience a close correlation between inflammation, pain, and depression²⁰.  Patients primarily seek to enhance their quality of life and place high expectations on the surgical intervention. It is the surgeon’s responsibility to clarify that the final outcome should be compared to the preoperative psychological and physical status of the patient. Severe joint degeneration and alignment deviation, together with comorbidities such as obesity, diabetes, preoperative anemia, chronic pain managed with ongoing opioid use, and anxiety-depressive traits, are significant predictors of suboptimal clinical, functional, and subjective postoperative outcomes1. It would be beneficial to compile all these parameters into “predictive outcome scores” that could improve the information provided to patients who are candidates for knee prosthesis surgery. By comparing patient expectations with preoperative scores, it may be possible to reduce the high percentage of postoperative dissatisfaction reported in the literature. The subjective parameter of “satisfaction” needs to be contextualized more effectively during the collection of results using PROMs. Commonly used questionnaires analyze the topic of “postoperative recovery” in various ways and through multiple questions, detailing the subjective quantification of the physical, psychological, and social aspects involved. However, the parameter of “satisfaction” is rarely treated as a standalone item with a specific meaning and evaluative role regarding the quality of life of patients. Questions such as “Are you satisfied with the results of the surgery you underwent?” and “Would you have the surgery again?” directly and indirectly reflect the projected goals achieved by patients. Satisfaction is not a fixed parameter; instead, it tends to fluctuate over time. As psychological and physical conditions improve over time, the assessment of satisfaction will become more objective and reliable. Consequently, it is helpful to track this subjective parameter through serial evaluations over time.

Limitations

This study has several limitations. The first is the small number of patients, which precludes complete statistical analyses. This small sample of patients does not allow for a statistical validation of the high percentage of satisfied patients regarding the results of the knee prosthesis surgery they underwent. This limited patient group did not allow for statistically significant conclusions about the impact of clinical-surgical “personalization” on overall patient satisfaction. Another limitation, introducing potential bias, is that all patients – although at varying stages of follow-up – were interviewed simultaneously. This prevented the evaluation of the temporal curve of both objective and subjective recovery. As a result, the assessment elements of the results were considered “static,” even though they are known to change over time. Another limitation of the study relates to how the questionnaire was administered. Telephone interviews for data collection are susceptible to various biases. Despite this, all contacted patients acknowledged the purpose of the call, consented to proceed with the interview, and in many cases expressed pleasure at being re-contacted by the surgeon who reached out to them. The PROM prepared and utilized for the telephone interviews with patients may appear overly concise, and its application could be subject to understandable criticism. It has not been validated, which limits its reliability as a tool. It is important to clarify that this work is part of a clinical audit process within the Orthopedics and Traumatology Unit of the Forlì facility of the AUSL of Romagna. The analysis of responses from the selected patients has, however, confirmed that efforts are being made to optimize the patient pathway for knee prosthesis surgery, following protocols that are continually evolving in both conceptual and technical aspects of surgery.

Conclusions

A high percentage of satisfied patients was observed regarding the outcomes achieved after knee prosthesis surgery across all patients included in this study. Patients who report overall satisfaction are those who consider their postoperative condition acceptable, particularly in relation to their preoperative state, following a process of psychological or subjective re-evaluation. The direct yes-or-no question effectively captured whether the knee prosthesis met patients’ expectations satisfactorily.

Informed Consent

The informed consent form was read aloud to the patient and explained prior to the start of the questionnaire. However, since the questionnaire was conducted via telephone, the form was not shared with the patient in written format. The study only included the participants who accepted the conditions of the informed consent. The Ethical Committee of Romagna has approved the informed consent form adopted for the study.

Ethical Approval

The study was approved by the CEROM (Ethical Committee of Romagna), with determination No. 1590 on May 22, 2023.

ORCID ID

Marcello Lughi: 0000-0002-5052-1002

Conflict of Interest

The author has no conflict of interest to declare.

Funding

None.

Availability of Data and Materials

Data and materials are available from the corresponding author upon reasonable request.

AI Disclosure

No form of generative artificial intelligence was used to write the manuscript.

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