The Influence of Radiological Severity and Symptom Duration of Osteoarthritis on Postoperative Outcome After Total Hip Arthroplasty: A Prospective Cohort Study

Duration of Symptoms Does Not Significantly Influence Short-term Outcomes for Patients Undergoing Periacetabular Osteotomy

Factors influencing the clinical outcomes after periacetabular osteotomy (PAO) have not been well explored. This study evaluated the influence of symptom duration in developmental dysplasia of the hip on short-term patient-reported outcomes after PAO. A retrospective review of prospectively collected data identified PAOs performed on 139 patients. Sixty-five patients were then stratified into two groups based on preoperative symptom duration: 2 years or less (n=22) vs more than 2 years (n=43). We compared the results of hip-specific patient-reported outcome surveys collected preoperatively and postoperatively. When comparing the two groups, we found no significant differences in clinical outcome scores except for the UCLA Activity Scale. The shorter duration group achieved improvement 6 months postoperatively on the visual analog scale average pain score (from 4.5 to 2.167; P=.0017), International Hip Outcome Tool-12 (from 42.95 to 59.19; P=.0176), and Harris Hip Score (from 53.88 to 69.88; P=.049). The longer duration group also achieved postoperative improvement across multiple surveys. Nevertheless, a multivariate analysis controlling for age, sex, and body mass index and found that symptom duration did not independently affect the change in clinical outcomes. Although PAO leads to improvements in functional status and pain, preoperative symptom duration does not significantly affect these clinical outcomes. [Orthopedics. 2023;46(6):365-372.].

Supraspinatus pathology on MRI is associated with degree of weakness on dynamic clinical strength testing

OBJECTIVE

To analyze shoulder strength and function in patients presenting with possible supraspinatus pathology and to ascertain if these clinical findings are associated with severity of supraspinatus pathology on MRI.

MATERIALS AND METHODS

In total, 171 patients with presumptive rotator cuff pathology and with preserved strength on standard rotator cuff examination were prospectively recruited. Patients were subjected to bilateral shoulder strength testing employing dynamometry; this included isometric strength testing at 90° of abduction, followed by eccentric assessment of isotonic strength from full abduction through the full range of motion until the arm rested at the patient's side. We calculated absolute strength and symptomatic-to-asymptomatic arm (S/A) strength ratios. On subsequent shoulder MRI, supraspinatus pathology was designated into one of seven categories. The association between strength measurements and MRI findings was analyzed.

RESULTS

Increasing lesion severity on MRI was associated with both decreasing absolute strength (no tear [59.9 N] to full-thickness tear [44.2 N]; P = 0.036) and decreasing S/A strength ratios during isotonic testing (no tear [91.9%] to full-thickness tear [65.3%]; P = 0.022). In contrast, there were no significant relationships between imaging severity and absolute strength or S/A strength ratios on isometric testing.

CONCLUSION

Severity of supraspinatus pathology on MRI was associated with dynamic clinical function. These results validate the clinical correlation between MRI designations of supraspinatus pathology and function and suggest the need for future work to investigate utility of dynamic (versus isometric) rotator cuff physical examination maneuvers.

What Preoperative Factors are Associated With Not Achieving a Minimum Clinically Important Difference After THA? Findings from an International Multicenter Study

BACKGROUND

Despite innovations in THA, there remains a subgroup of patients who experience only modest pain relief and/or functional improvement after the procedure. Although several studies have previously sought to identify factors before surgery that were associated with achieving or not achieving a meaningful improvement after THA, there is no consensus on which factors are most associated; many studies have relied on single-center or single-country multicenter studies for their cohorts.

QUESTIONS/PURPOSES

We sought to identify (1) the proportion of patients who do not achieve a minimum clinically important difference (MCID) in pain and function 1 year after THA, and (2) the preoperative factors that were associated with not achieving MCIDs in pain and function 1 year after THA.

METHODS

This retrospective study analyzed data gathered from a prospective international, multicenter study examining the long-term clinical outcomes of two different polyethylene liners and two different acetabular shells. A total of 814 patients from 12 centers across four countries were enrolled in the study, with the final cohort consisting of 594 patients (73%) who all had complete preoperative and 1-year PROMs as well as a valid preoperative radiograph used to measure minimum joint space width. The outcomes in this study were achieving evidence-derived MCIDs in (1) pain, defined as a reduction of two points on an 11-point (0 = very little, 10 = worst imaginable) numerical rating scale (NRS) for hip-related pain or reporting a 1 year NRS-pain score of 0, and (2) function, defined as an increase equal to or greater than 8.3 on the SF-36 Physical Function subscore (range: 0 to 100; 0 = maximum disability, 100 = no disability) or reporting a 1-year SF-36 Physical Function subscore within the 95th percentile of scores in our cohort. All demographic variables, such as age, sex, country; surgical factors, including body mass index (BMI), surgical approach, acetabular liner type, and preoperative PROMs, were included as covariates in a binary logistic regression model. We used a backwards stepwise elimination algorithm to reach the simplest, best-fit model.

RESULTS

In the final analysis cohort of 594 patients, 54 patients (9%) did not achieve the MCID in pain and 146 (25%) patients did not achieve the MCID in physical function after THA. After controlling for potential confounding variables such as age, BMI, and preoperative PROMs, we found that higher joint space width (odds ratio (OR) = 2.19; 95% confidence interval (CI) = 1.49-3.22; p < 0.001), lower preoperative SF-36 Mental Component Summary (MCS) (OR = 0.95; 95% CI = 0.93-0.98; p = 0.001), and female sex (OR = 2.04; 95% CI = 1.08-3.82; p = 0.027) were associated with failing to achieve a MCID in pain. It is important to note that the effect size of having a higher preoperative SF-36 MCS is small, with a 1- or 10-point increase in SF-36 MCS decreasing the odds of a patient not achieving the pain MCID by 5% or 63%, respectively.In a separate multivariable model, after controlling for potential confounding variables such as age, BMI, and preoperative PROMs, we found that higher joint space width (OR = 1.54; 95% CI = 1.18-2.02; p = 0.002), higher preoperative Harris hip score (HHS) (OR = 1.01; 95% CI = 1.00-1.03; p = 0.019) and undergoing surgery in Scandinavia (OR = 1.73; 95% CI = 1.17-2.55; p = 0.006) were associated with failing to achieve a MCID in physical function. It is important to note that the effect size of having a higher preoperative HHS is very small, with a 1- or t10-point increase in HHS increasing the odds of not achieving the physical function MCID by only 1% or 15%, respectively.

CONCLUSIONS

These findings suggest that surgeons should counsel patients with high joint space width, female patients, and patients undergoing surgery in Scandinavia that they may be much less likely to experience meaningful pain relief or functional improvement after THA, and in light of that, determine whether indeed surgery should be postponed or avoided in those patients. Lower SF-36 MCS score and higher HHS before surgery were also found to be associated with not achieving MCIDs in pain and physical function, respectively, after surgery, but both had relatively small effect sizes. Future prospective studies may consider exploring the relationship between less pain relief or functional improvement and the risk factors identified in this study, such as high joint space width, to validate our findings and determine if the variables we identified are truly predictive of worse postoperative outcomes. Future retrospective studies of regional or national registry data should use the analysis methods presented within this study to both identify the portion of the THA patients who do not achieve a MCID in pain or physical function after surgery and confirm if the preoperative risk factors for poor improvement identified within our international, multicenter cohort are also found in a larger patient population with more diverse implants and comorbidities.

LEVEL OF EVIDENCE

Level III, therapeutic study.