Osteoarthritis of the knee is one of the most common musculoskeletal conditions affecting the elderly population worldwide. With progressive aging and the increasing prevalence of obesity, the burden of knee osteoarthritis continues to rise, significantly impacting mobility, independence, and quality of life among older adults. In advanced stages of the disease, conservative measures such as medications, physical therapy, and intra-articular injections often fail to provide sustained relief, making surgical intervention the treatment of choice for many patients. Total knee arthroplasty (TKA) has long been established as an effective and reliable solution for end-stage knee osteoarthritis. Over the past few decades, the global demand for TKA has grown exponentially, with projections suggesting a substantial increase in both primary and revision procedures in the coming years to meet the needs of the aging population¹. While conventional TKA provides excellent pain relief and functional improvement, concerns regarding postoperative recovery, muscle weakness, and delayed return to daily activities remain significant, especially in elderly patients².  Following TKA, many individuals experience impairments such as quadriceps weakness, limited joint mobility, and functional restrictions that can persist for months after surgery³. Quadriceps muscle strength is a critical determinant of postoperative outcomes, as it influences gait, stability, and the ability to perform daily activities such as climbing stairs or rising from a chair⁴. However, conventional TKA approaches often require extensive soft tissue dissection, which can contribute to muscle trauma, pain, and delayed rehabilitation⁵. In recent years, the concept of Total knee arthroplasty (TKA) has gained popularity as an alternative surgical approach aimed at reducing postoperative morbidity and enhancing recovery. TKA techniques involve smaller incisions, reduced soft tissue trauma, and preservation of key anatomical structures, particularly the quadriceps mechanism. These modifications are intended to minimize pain, accelerate rehabilitation, and improve early functional outcomes compared to traditional methods⁶. Evidence suggests that early quadriceps strength loss following TKA is multifactorial, involving both muscle atrophy and impaired voluntary activation⁷. The midvastus and subvastus approaches, which are commonly utilized in TKA, are designed to preserve muscle integrity and reduce the extent of trauma to the extensor mechanism, thus potentially mitigating strength deficits and enhancing recovery⁸. Moreover, minimizing soft tissue disruption during surgery is particularly advantageous for elderly patients, who often have reduced physiological reserves and a higher risk of postoperative complications. While the theoretical benefits of TKA are promising, the literature reveals mixed results regarding its superiority over conventional techniques. Some studies have demonstrated improvements in early muscle strength, reduced pain, and faster rehabilitation with TKA, but others report no significant differences in long-term functional outcomes or performance-based measures⁹. This discrepancy highlights the need for further prospective studies to assess the true impact of TKA, particularly in elderly patients who may have unique anatomical and physiological considerations compared to younger populations. Additionally, although improvements in surgical technique and perioperative management have enhanced the safety profile of TKA, optimizing functional outcomes in elderly patients remains a challenge. Functional independence, quality of life, and patient satisfaction are critical goals of TKA, especially in older individuals for whom maximizing mobility is essential to maintain autonomy and prevent secondary complications such as falls, deconditioning, and social isolation¹⁰.Given the growing demand for TKA in elderly individuals and the evolving role of minimally invasive techniques, there is a clear need to evaluate the functional outcomes and safety of TKA in this specific population. Understanding the effectiveness of TKA in improving pain, joint mobility, muscle strength, and overall function is essential to guide clinical decision-making, optimize surgical approaches, and enhance patient outcomes.

This prospective study was conducted to evaluate the functional outcomes of Total knee arthroplasty (TKA) in elderly patients. A total of 70 patients diagnosed with end-stage knee osteoarthritis who were scheduled for primary total knee arthroplasty were enrolled in this study. All participants were aged 60 years or older, with inclusion criteria specifying patients with severe degenerative osteoarthritis of the knee joint, as classified by the Kellgren-Lawrence Grade III or IV, who were medically fit for surgery. Patients with inflammatory arthritis, post-traumatic arthritis, prior knee surgeries, or significant neuromuscular disorders were excluded.

Preoperative assessments included detailed clinical evaluation, radiographic analysis using standing anteroposterior, lateral, and skyline views of the knee, and documentation of baseline functional scores. The functional status was assessed using standardized tools, including the Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion (ROM) measurements.

All surgeries were performed by the same senior orthopedic surgeon experienced in techniques to reduce variability. A standard surgical approach was employed, utilizing a mid-vastus or sub-vastus technique with limited soft tissue dissection, thereby preserving the extensor mechanism. Cemented total knee prostheses of the same design and manufacturer were used for all cases to maintain uniformity. Intraoperative details such as tourniquet time, operative duration, and blood loss were recorded.

Postoperative rehabilitation followed a standardized protocol emphasizing early mobilization and weight-bearing as tolerated. Thromboprophylaxis and pain management were provided according to institutional guidelines. All patients were followed at regular intervals of 6 weeks, 3 months, 6 months, and 1 year postoperatively. During each follow-up visit, clinical assessments were performed, including evaluation of pain, range of motion, and functional status using KSS, WOMAC, and visual analog scale (VAS) scores.

The primary outcome measure was the improvement in functional scores postoperatively. Secondary outcomes included range of motion, pain relief, complication rates, and overall patient satisfaction. Statistical analysis was conducted using appropriate methods, with a significance level set at p < 0.05.

Table 1: Baseline Demographic and Clinical Characteristics

The study included a total of 70 elderly patients undergoing Total knee arthroplasty (TKA). The mean age of the study population was 67.45 ± 4.85 years, indicating that the cohort primarily consisted of elderly individuals as per the inclusion criteria. In terms of gender distribution, 28 patients (40.00%) were male, while 42 patients (60.00%) were female, showing a slightly higher representation of female patients, consistent with the known higher prevalence of osteoarthritis among elderly women.

The mean body mass index (BMI) was 27.68 ± 2.94 kg/m², which falls within the overweight category, a common risk factor for osteoarthritis progression. Regarding disease severity, 42.86% (30 patients) were classified as Kellgren-Lawrence Grade III, while 57.14% (40 patients) were Grade IV, suggesting that the majority of patients had advanced osteoarthritis.

Preoperative functional status assessments showed a mean Knee Society Score (KSS) of 45.32 ± 5.75, reflecting significant functional limitation. The mean preoperative WOMAC score was 68.25 ± 6.58, indicating a high degree of pain, stiffness, and functional disability. The mean preoperative range of motion (ROM) was 91.85 ± 7.45 degrees, highlighting the restricted joint mobility common in advanced knee osteoarthritis.

Table 2: Comparison of Functional Scores Preoperative vs. 1-Year Postoperative

There was a statistically significant improvement in all measured functional outcomes one year after TKA. The mean KSS increased from 45.32 ± 5.75 preoperatively to 85.68 ± 6.42 postoperatively (p < 0.001), demonstrating substantial improvement in knee function and stability. Similarly, the mean WOMAC score decreased markedly from 68.25 ± 6.58 to 22.45 ± 5.38 (p < 0.001), reflecting a significant reduction in pain, stiffness, and functional limitations.

The range of motion (ROM) showed considerable improvement, increasing from 91.85 ± 7.45 degrees preoperatively to 118.63 ± 6.27 degrees at 1-year follow-up (p < 0.001), indicating restored joint mobility. Pain levels, as measured by the Visual Analog Scale (VAS), significantly decreased from 7.15 ± 0.85 to 2.10 ± 0.72 (p < 0.001), highlighting the procedure's effectiveness in alleviating pain. These findings confirm that TKA leads to significant improvements in pain relief, joint function, and mobility in elderly patients.

Table 3: Postoperative Complications

Postoperative complications were minimal in this cohort. Superficial infections were reported in 2 patients (2.86%), all of which were managed successfully with standard wound care and antibiotics. There were no cases of deep infection (0.00%), reflecting the efficacy of surgical sterility and perioperative protocols. One patient (1.43%) developed deep vein thrombosis (DVT), which was treated conservatively with anticoagulation. Wound healing delays were observed in 3 patients (4.29%), but these did not progress to serious complications. Notably, 64 patients (91.43%) experienced no complications, underscoring the safety of minimally invasive TKA in this elderly population.

Table 4: Patient Satisfaction at 1 Year Postoperative

Patient satisfaction was notably high following TKA. At the 1-year follow-up, 48 patients (68.57%) reported being very satisfied with the outcome, while 16 patients (22.86%) were satisfied. Only 4 patients (5.71%) expressed a neutral opinion regarding their surgical results, and 2 patients (2.86%) reported dissatisfaction. The high satisfaction rates are consistent with the significant functional and pain improvements observed in this study, emphasizing the success of the minimally invasive approach in meeting patient expectations.

Table 5: Subgroup Analysis of Functional Improvement by Gender

Subgroup analysis based on gender revealed no statistically significant differences in functional improvements between male and female patients. The mean improvement in KSS was 39.82 ± 6.12 for males and 40.45 ± 6.58 for females (p = 0.582), showing similar functional gains across genders. The mean improvement in WOMAC scores was also comparable, with 45.15 ± 5.78 for males and 45.92 ± 6.04 for females (p = 0.415).

Range of motion improved by 27.85 ± 4.65 degrees in males and 27.30 ± 5.10 degrees in females (p = 0.648), while the reduction in VAS pain scores was nearly identical between the two groups (5.02 ± 0.85 for males vs. 5.05 ± 0.80 for females, p = 0.813). These results suggest that TKA offers consistent and effective functional improvements in both male and female elderly patients, with no gender-based differences in clinical outcomes.

Table 1: Baseline Demographic and Clinical Characteristics (n = 70)

Table 2: Comparison of Functional Scores Preoperative vs. 1-Year Postoperative

Table 3: Postoperative Complications (n = 70)

Table 4: Patient Satisfaction at 1 Year Postoperative (n = 70)

Table 5: Subgroup Analysis of Functional Improvement by Gender

The present study demonstrated significant improvements in functional outcomes among elderly patients undergoing total knee arthroplasty (TKA). The mean age of our cohort was 67.45 years, comparable to the study by Bonutti et al., where the average patient age was reported as 68.20 years for TKA procedures in an elderly population, highlighting the suitability of this technique for older adults with advanced osteoarthritis (Grade III and IV)¹¹. The mean preoperative ROM in our study was 91.85°, consistent with their reported preoperative ROM of 90.50°, indicating similar baseline joint limitations among elderly patients selected for surgery¹¹.

Our study reported a significant improvement in Knee Society Scores (KSS) from 45.32 preoperatively to 85.68 at one year postoperatively (p < 0.001). These findings align with the results of Tria et al., who observed an improvement in KSS from 44.10 to 86.40 following MI-TKA in their elderly cohort, confirming the efficacy of the minimally invasive approach in restoring joint stability and function¹². Such functional gains are vital, especially in elderly populations where mobility directly influences independence and quality of life.

The WOMAC score in our study decreased substantially from 68.25 to 22.45 postoperatively, indicating notable reductions in pain, stiffness, and disability. This result is comparable to the findings of Haas et al., who reported a decrease in WOMAC scores from 70.85 to 23.65 following TKA, demonstrating similar functional improvements across different patient groups¹³. These improvements further support the role of minimally invasive techniques in reducing the symptomatic burden of advanced knee osteoarthritis.

Postoperative range of motion (ROM) significantly increased from 91.85° to 118.63° in our cohort. This finding is in accordance with studies by Lombardi et al., where ROM improved from 92.10° to 119.50° post- TKA, supporting the effectiveness of limited  soft tissue dissection techniques in preserving extensor mechanisms and enhancing mobility outcomes¹⁴. Improved ROM is particularly relevant in elderly individuals where joint flexibility directly influences daily activities and fall prevention.

Our postoperative complication rate was low, with 91.43% of patients experiencing no complications, and only minor events such as superficial infections (2.86%), DVT (1.43%), and wound healing delays (4.29%) were reported. These outcomes compare favorably to the results by Dalury et al., who reported an overall complication rate of 9.85% in their TKA cohort, suggesting that with meticulous technique and standardized protocols, complication rates can be minimized in elderly patients¹⁵.

High patient satisfaction was observed in this study, with 68.57% of patients being very satisfied at the 1-year follow-up. These satisfaction rates are consistent with the findings of Bolognesi et al., who reported very satisfied patients accounting for 70.20% following TKA, reinforcing that patient expectations regarding pain relief and functional restoration can be successfully achieved using minimally invasive approaches¹⁶. Such high satisfaction rates are critical given the impact of TKA outcomes on quality of life among elderly individuals.

Total knee arthroplasty (TKA) in elderly patients provides significant improvements in functional outcomes, pain relief, and joint mobility with a low complication rate and high patient satisfaction. The technique demonstrated substantial gains in Knee Society Scores, WOMAC scores, range of motion, and pain reduction at one-year follow-up. Additionally, the outcomes were consistent across genders, confirming the procedure's safety and effectiveness in elderly populations with advanced knee osteoarthritis.

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