Functional impact and quality of life after total hip arthroplasty for hip osteoarthritis. A retrospective study of 200 cases.

Study design

Approval was obtained from the Institutional Review Board (IRB) of Fattouma Bourguiba Hospital (CEM-2018-12-15) for the conduct of this retrospective study performed on patients who underwent primary THA for hip osteoarthritis from January 2019 to December 2020 at Fattouma Bourguiba Hospital. The design and reporting were performed in accordance to the Declaration of Helsinki. The written informed consent was waived by the IRB due to the retrospective nature of the study. Patient confidentiality was maintained through anonymized data collection and analysis.

The inclusion criteria for the patient’s analysis were: (1) patients undergoing THA for hip osteoarthritis, whether degenerative or secondary to a systemic disease; (2) patients capable of providing written or verbal responses to questionnaires; and (3) those with minimum follow-up duration of two years postoperatively.

The following patients were excluded: (1) post-traumatic THA cases; (2) patients with active infections or acute exacerbations of chronic medical conditions; (3) patients unable to complete self-reported questionnaires due to cognitive impairment; and (4) patients with significant neuromuscular or vascular comorbidities affecting lower limb function.

Data collection protocol

We systematically collected data from electronic medical records using a standardized case report form that included (1) demographic and epidemiological data (age, sex, body mass index (BMI), occupational status, comorbidities, preoperative functional status), (2) clinical parameters (affected side and symptom duration, gait perimeter assessment, surgical approach, implant characteristics) and (3) postoperative evolution (immediate and late complications, rehabilitation protocol details). The scoring was based on a direct interview with the patient (190 cases) during follow-up and in rare cases (10 patients) it was based on a telephone interview with clarification of contentious issues.

Functional evaluation

We assessed hip function using the validated Postel-Merle d’Aubigné (PMA) score preoperatively and at the final follow-up. This 18-point scale evaluates pain (0-6 points), mobility (0-6 points), and walking ability (0-6 points).⁵ Scores were categorized as Very good (≥12 points), Good (10-11 points), Average (9 points), Low (8 points) and Poor (≤7 points).

Quality of life assessment

We employed four validated instruments:

Statistical analysis

We performed all analyses using SPSS version 26 (IBM Corp.). Descriptive statistics included means for normally distributed continuous variables, medians for non-normal distributions, and frequencies for categorical variables. For inferential analysis, we used Student’s t-test for normally distributed continuous variables, Pearson’s chi-square or Fisher’s exact test for categorical variables, and Pearson correlation for continuous variable associations. All tests were two-tailed with a p = 0.05 significance threshold.

Study population and baseline characteristics

This study included 200 eligible patients. The cohort had a male predominance (59% male, 41% female), with a male-to-female ratio of 1.43. The mean age was 49 ± 15.59 years (range: 35–78), with most patients (62.5%) aged between 40 and 65 years. The right hip was operated on 120 patients and the left hip on 80. THA was bilateral in 30 patients ( Table 1).

BMI distribution revealed that 20% of patients were obese, 39% overweight, and 41% had a normal BMI. Occupational status varied: 51% were employees, 24% were housewives, and 25% were retired. Metabolic syndrome was present in 30% of the cohort.

The average duration of symptoms was four years, with extremes ranging from two to six years. Primary hip joint involvement was observed in 52.5% of cases, while 47.5% were secondary to systemic disease mainly rheumatoid arthritis and ankylosing spondylitis. All patients presented with a reduced gait perimeter, with a median walking distance of 200 ± 158 meters preoperatively.

In all cases, the surgical approach used was the posterolateral Moore technique. Ceramic on-ceramic articulation was used in 60% of cases. Metal on highly cross-linked polyethylene was used in 40% of cases. Regarding prosthesis fixation, femoral stems were cemented in 37% of cases, while 63% were uncemented. These ratios are similar for acetabular components (38% cemented and 62% uncemented).

Five cases of prosthesis dislocation occurred within two months of surgery, with no recurrence. There were also ten cases of early sepsis, which were managed through repeat surgery involving debridement and lavage, as well as appropriate antibiotic therapy. The outcome was good. No late complications were reported at the last follow-up.

Postoperatively, all patients stood up on the day of the operation, and 75% began ambulating immediately the day after. Rehabilitation protocol applied to all patients included muscle strengthening, analgesic physiotherapy, and patient education to prevent dislocating movements of the prosthesis.

After a mean follow-up of three years (range: two to four years), 82.5% walked independently, 13.7% used a single cane, and only 3.8% required two canes, demonstrating significant functional improvement (p = 0.017).

Functional and quality of life outcomes

THA led to significant functional improvements ( Table 2), as demonstrated by the PMA scale (p = 0.008). The mean PMA score more than doubled, increasing from 7/18 (±2) preoperatively to 14/18 (±4) postoperatively. Clinically, this translated to a dramatic decline in patients with “poor” function (53.8% preoperatively vs. postoperatively) and a substantial rise in those achieving “very good” scores (87.2%).

Patients also experienced marked enhancements in quality of life, measured by the SF-12 survey. The PCS improved from 29.76 to 48.71 (p < 0.001), while the MCS rose from 49.24 to 54.49 (p < 0.001), indicating better physical and psychological well-being.

Hip-specific function, assessed via the HOOS, showed significant gains (p < 0.001), with the global score improving from 35 to 76. Preoperatively, the greatest limitations were in Sports/Leisure activities, while the Symptoms domain was the least severe among the HOOS subscales. Postoperatively, Activity domains improved the most, though Sports/Leisure remained challenging.

Sleep quality, evaluated using the PSQI, also improved significantly, with scores dropping from 7/21 (±2.75) to 3/21 (±2.07) (p < 0.001). The proportion of “good sleepers” (PSQI ≤5) increased from 24.4% to 87.2%.

Psychological assessments using the HADS revealed reduced depression from 6.8/21 ±2.86 to 3.8/21 ±2.21 (p < 0.001) and anxiety from 8.4/21 ±3.06 to 4.8/21 ±2.66) (p < 0.001). Preoperatively, 12.8% had “definite depression” and 28.2% had “definite anxiety”; postoperatively, these rates fell to 9% and 5.1%, respectively.

Factors influencing postoperative quality of life after total hip arthroplasty

This study identified several significant factors associated with improved quality of life following THA ( Table 3). Physical health outcomes (SF-12 PCS) showed positive correlations with a history of rheumatic diseases (p = 0.017), post-operative walking autonomy (p = 0.011), shorter hospital stay (p = 0.048), and earlier mobilization (p = 0.046). Mental health (SF-12 MCS) was significantly linked to walking autonomy (p = 0.011), greater walking distance (p = 0.003), and BMI (p = 0.043).

Hip function, assessed by the HOOS, improved with ceramic on ceramic articulation (p = 0.03), younger age (p = 0.002), earlier post-operative mobilization (p = 0.027), and higher post-operative PMA scores (p = 0.01). Sleep quality was positively associated with walking distance (p = 0.018), while depression scores decreased with increased walking distance (p = 0.037) and higher BMI (p = 0.043). No significant associations were found between anxiety and any of the studied variables (p > 0.05).