Preoperative Factors Associated With Low Back Pain Improvement After Total Hip Arthroplasty in a Japanese Population

Optimal surgery sequence in the treatment of degenerative hip-spine syndrome: a propensity score-based inverse probability of treatment weighting analysis

BACKGROUND

The coexistence of spinal degenerative diseases and hip joint degeneration is common among middle-aged and elderly individuals, causing significant suffering and economic burden for patients. Total hip arthroplasty (THA) and lumbar fusion (LF) are primary treatment options for this combined condition, but the impact of the surgical sequence on patient outcomes remains unclear. Hence, this study aims to evaluate the effects of the surgical sequence of THA and LF on symptom recovery, changes in sagittal spine-pelvis parameters, and the incidence of long-term complications in patients.

METHODS

A retrospective analysis was conducted on 104 patients diagnosed with hip-spine syndrome (HSS) who underwent THA and LF at the Chinese PLA General Hospital. IPTW was implemented to control potential confounding factors. The impact of surgical sequence on clinical function scores, radiological parameters, and long-term complications was evaluated before and after conducting IPTW. Patients who underwent THA surgery first, followed by LF surgery, were categorized as the THA→LF group; conversely, those who underwent LF surgery first, followed by THA surgery, were categorized as the LF→THA group. Clinical function scores included the Oswestry Disability Index (ODI), Japanese Orthopedic Association (JOA) score, and Harris Hip Score for both groups. Long-term complications assessed in this study included instances of Proximal Junctional Kyphosis (PJK), internal fixation loosening or failure, as well as hip prosthesis dislocation. Radiological parameters included Pelvic Tilt (PT), Pelvic Incidence (PI), Pelvic Incidence minus Lumbar Lordosis (PI-LL), Sacral Slope (SS), and Lumbar Lordosis (LL).

RESULTS

Before conducting IPTW, there were significant differences between the two groups across multiple variables, including age (P = 0.035), fixation stage (P = 0.042), preoperative PT (P = 0.005), preoperative PI-LL (P = 0.004), and preoperative LL (P = 0.040). After conducting IPTW, all baseline data variables had P-values greater than 0.50, indicating that the baseline characteristics between the two groups were comparable. Following IPTW, the study found significant improvements in postoperative ODI, JOA score, and Harris Hip Score for both groups (P < 0.001), indicating that both surgical sequences were effective in enhancing clinical functional activity. However, there were no significant differences between the groups. Additionally, there was no significant difference in the long-term complication rates between the two groups. Regarding radiological parameters, the PT in the THA→LF group was significantly lower than that in the LF→THA group (P = 0.043), while the SS was significantly higher (P = 0.028) at the last follow up after conducting IPTW.

CONCLUSION

Compared to preoperative assessments, both surgical sequences significantly improve postoperative clinical function scores and radiological parameters for patients. When comparing between the two groups, the surgical sequence exhibits equivalent effects on functional improvement and complication rates. The radiological outcomes indicate that the THA→LF group shows more pronounced effects on PT and SS, suggesting a more favorable impact on pelvic alignment in patients undergoing this sequence. The use of the IPTW method successfully eliminates differences in baseline characteristics, enhancing the reliability of the results. Future research is warranted to further explore these findings and their implications for surgical decision-making in HSS patients.

Preoperative radiographical degenerative lumbar spondylolisthesis does not affect clinical outcomes of total hip arthroplasty

INTRODUCTION

Degenerative lumbar spondylolisthesis (DLS) is sometimes found in preoperative spine radiographs before total hip arthroplasty (THA). However, whether DLS affects the clinical outcomes of THA and whether the slip is improved by THA remain unclear. This study investigated the clinical outcomes of THA in patients with DLS and change in the slip percentage of DLS after THA.

MATERIALS AND METHODS

We included 369 patients who underwent primary THA due to hip osteoarthritis between December 2015 and February 2022. The patients were classified into the DLS or non-DLS group by evaluating preoperative whole-spine radiographs in the standing position. Preoperative sagittal spinal parameters, preoperative and 1-year postoperative Harris hip score, Oxford hip score, and slip percentage of DLS were evaluated. Multiple regression analysis was performed to identify the factors associated with DLS.

RESULTS

Of the 369 patients, 101 (27.4%) were classified into the DLS group. Multivariate analysis revealed that age (odds ratio (OR) per unit: 1.04, p < 0.01) and pelvic incidence (PI) (OR per unit: 1.04, p < 0.01) were significantly associated with DLS. Preoperative and postoperative clinical outcomes between the DLS and non-DLS groups were not significantly different. The preoperative and postoperative percentages of slip in the DLS group did not change significantly from 16.9% ± 6.2% to 16.7% ± 6.7% (p = 0.47). Patients with slip progression ≥ 2.5% of slip percentage were 19 (18.8%), who were younger (p = 0.02) and had higher PI (p = 0.01) and sacral slope (p = 0.03) than those with slip improvement.

CONCLUSIONS

Age and PI were significantly associated factors for DLS. The slip was not improved after THA. The clinical outcomes of THA in the DLS group were not affected. Longer-term follow-up studies are essential to elucidate the hip-spine relationship.

Spinopelvic interactions in total hip arthroplasty: 295 patients followed for a minimum follow-up of 10 years

BACKGROUND

Concurrent spinal pathology is frequent in patients undergoing total hip arthroplasty (THA). In this study we examined whether spinopelvic interactions affect THA outcomes at a minimum follow-up of 10 years.

PATIENTS AND METHODS

295 patients with a mean age of 63.3 (range 56‒80) years receiving a THA between 2006 and 2009 were assessed. Of these, 195 had mild lumbar disc degeneration and 100 had advanced lumbar spondylosis. We analysed the changes in the Harris Hip Score (HHS) and the survival rate for postoperative low back pain (LBP) and dislocation. Changes in acetabular component position, sacro-femoral-pubic (SFP) and pelvic obliquity (PO) angles were assessed with radiological images.

RESULTS

The mean HHS was lower in female patients (p = 0.009), patients >65 years of age (p < 0.001) and those with advanced lumbar spondylosis (p = 0.002). 52 (71.2%) of the patients reporting preoperative LBP experienced improvement after THA while 47 (21.1%) of those without preoperative LBP postoperatively reported new onset LBP. Female patients (p = 0.025; hazard ratio [HR]: 1.831; 95% CI, 1.081-3.101) and those with preoperative LBP (p = 0.007; HR 2.068; 95% CI, 1.221-3.504) were at a higher risk of developing postoperative LBP at 10 years. 4 out of 9 THA dislocations were late and had shown decreasing SFP angle values over time. Acetabular component inclination and anteversion angles increased over time, whereas the SFP angle was associated with sex and age and the PO angle with age and the severity of any preoperative lumbar degeneration.

CONCLUSIONS

Concurrent spinal pathology influences THA outcomes at a minimum follow-up of 10 years. Sex, age, and associated lumbar degeneration can affect clinical and radiological changes over time. A decrease in SFP angle values over time was found in patients sustaining late dislocation.

Association between physical measures of spinopelvic alignment and physical functioning with patient reported outcome measures (PROMs) after total hip arthroplasty: Protocol for systematic review and meta-analysis

INTRODUCTION

Prevalence of total hip arthroplasty (THA) has trended upwards over past decades and is projected to increase further. Optimizing outcomes after surgery is essential to avoid surgical revision and maximize outcomes. Low back pain is reported as a problem post THA. Patient-reported outcome measures (PROMs) are commonly used to evaluate THA outcomes but have limitations (e.g., ceiling effects). It is therefore important to assess a comprehensive range of outcomes. Physical outcome measures of spinopelvic alignment and physical functioning demonstrate potential value, but no evidence synthesis has investigated their association with PROMs. The objectives of this systematic review are to evaluate the association between spinopelvic alignment and physical outcome measures of physical functioning with PROMs and characteristics of low back pain after THA.

METHODS AND ANALYSIS

This protocol is aligned with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Cross-sectional and longitudinal cohort studies evaluating the association between the physical outcome measures and PROMs (any outcome measures reported) following THA by any approach/implant will be included except surface replacement and revision THA. Studies investigating THA for developmental pathology and inflammatory conditions will be excluded. A systematic search in MEDLINE (Ovid), Embase (Ovid), Scopus, Web of Science, CINAHL, and the grey literature will be carried out from inception to July 31, 2023. Two independent reviewers will evaluate eligibility of retrieved articles, extract data and assess risk of bias (NIH quality assessment tool) of included studies. A third reviewer will mediate disagreements. Random-effects meta-analyses will be conducted if studies are sufficiently homogeneous in design, population, physical measures and PROMs; reporting odds ratios and 95% confidence intervals. Where meta-analyses are not possible, a narrative synthesis will be conducted. Confidence in cumulative evidence will be assessed using a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation).

PROSPERO REGISTRATION NUMBER

PROSPERO Registration number CRD42023412744.

Association between cup orientation and low back pain after total hip arthroplasty in patients with osteonecrosis of the femoral head

BACKGROUND

Postoperative low back pain (LBP) following total hip arthroplasty (THA) is classified as secondary hip-spine syndrome. The purpose of this study was to explore the correlations between cup orientation of THA and postoperative LBP in patients with osteonecrosis of the femoral head (ONFH).

METHODS

A retrospective cohort study included 364 ONFH patients who underwent bilateral THA between January 2011 and December 2020. Among them, 53 patients (14.6%) experienced postoperative LBP at the end of follow-up and were designated as pain group (PG). A control group (CG) consisting of 106 patients with similar age, sex, and body mass index (BMI) to those in the PG was selected. Postoperative LBP in the PG was assessed using the visual analogue scale (VAS). Demographic data, clinical information, and radiographic criteria were evaluated as potential predictors of LBP.

RESULTS

Patients in PG (mean age, 47.3 years [range, 27 to 75 years]; 42 [79%] male) had a mean VAS score of 4.6 (range, 1 to 9) compared with 0 for the patients in CG (mean age, 47.6 years [range, 19 to 77 years]; 84 [79%] male). There were no significant differences in clinical data between the two groups (p > 0.05). Preoperative radiographic variables also showed no significant differences between the PG and CG (p > 0.05). However, the postoperative inclination, anteversion, and standing ante-inclination (AI) were significantly lower in the PG compared to the CG, whereas the sitting and standing sacral slope (SS) were significantly higher (p < 0.05). Moreover, the variations in standing AI, standing and sitting pelvic tilt (PT) were significantly lower in the PG compared to the CG, while the variations in standing and sitting SS and lumbar lordosis (LL) were significantly higher (p < 0.05). The variation in standing AI in the PG showed a significantly correlation with the variation of standing SS, standing PT, and LL (p < 0.05).

CONCLUSION

Postoperative LBP in ONFH patients after bilateral THA is significantly associated with the intraoperative cup orientation. The variation in standing AI is correlated with the variations in standing SS, standing PT, and LL, potentially contributing to the development of postoperative LBP.

How Do Spinal Parameters Change in Patients Who Have Improvement of Low Back Pain After Total Hip Arthroplasty? A Propensity Score-Matched Cohort Study

BACKGROUND

Many studies have demonstrated that low back pain (LBP) improves after total hip arthroplasty (THA). However, the mechanism underlying this improvement remains unclear. We aimed to investigate changes in the spinal parameters of patients who had LBP improvement after THA to elucidate the mechanism of LBP improvement.

METHODS

We included 261 patients who underwent primary THA between December 2015 and June 2021 and had a preoperative visual analog scale score of ≥ 2 for LBP. The patients were classified into the LBP-improved or LBP-continued groups based on the visual analog scale for LBP at 1 year after THA. Preoperative and postoperative changes in the coronal and sagittal spinal parameters were compared between the 2 groups after propensity score matching for age, sex, body mass index, and preoperative spinal parameters.

RESULTS

A total of 161 patients (61.7%) were classified into the LBP-improved group. After 85 patients in both groups were matched, the LBP-improved group showed significant differences in spinal parameter changes, which were a higher lumbar lordosis (LL) (P = .04) and lower sagittal vertical axis (SVA) (P = .02) and pelvic incidence (PI) minus LL (PI-LL) (P = .01) postoperatively, whereas the LBP-continued group showed worsened changes in LL and SVA and PI-LL mismatch.

CONCLUSION

Patients who had LBP improvement after THA had significant differences in spinal parameter changes in LL, SVA, and PI-LL. These spinal parameters may be the key factors in the mechanism of LBP improvement after THA.

Clinical significance of relative pelvic version measurement as a predictor of low back pain after total hip arthroplasty

PURPOSE

To evaluate the association between the preoperative global alignment and proportion (GAP) score and low back pain (LBP) after total hip arthroplasty (THA).

METHODS

This was a retrospective case-control study of 200 patients who underwent primary unilateral THA for hip osteoarthritis. The following variables were compared between individuals with (n = 76) and without (n = 124) LBP after THA over a mean follow-up of 2 years: age, sex, GAP score, and patient-reported outcome measures. Logistic regression and receiver operating characteristic curve analyses were used to detect predictive factors.

RESULTS

The following parameters were predictive of post-THA LBP: relative pelvic version (RPV) <-7° (odds ratio, 1.43; 95% confidence interval, 1.10-1.72; P = 0.032) and relative lumbar lordosis <-15° (odds ratio, 1.13; 95% confidence interval, 1.04-2.13; P = 0.041) preoperatively. Using an RPV cutoff value of - 7° (specificity 61/64 = 0.953; sensitivity 121/136 = 0.890), there were significant between-group differences in LBP visual analog scale (P = 0.020), Oswestry Disability Index (ODI, P = 0.014), EuroQol 5-Dimension (P = 0.027), Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR, P = 0.012), patient satisfaction (P = 0.024). There was clinically meaningful improvement for LBP visual analog scale (P = 0.001), ODI (P = 0.004), and HOOS JR (P < 0.001). The RPV before THA was correlated with HOOS JR (r = 0.773, P = 0.012) and ODI (r = - 0.602, P = 0.032) postoperatively.

CONCLUSION

Among the GAP score, a moderate-to-severe pelvic retroversion was significantly associated with LBP post-THA. The RPV measurement may be a useful predictor of THA outcome, which may influence patient satisfaction.

Total hip arthroplasty in patients with vertebral compression fracture is associated with poor clinical outcomes - retrospective analysis on 453 cases

PURPOSE

Total hip arthroplasty (THA) is increasingly performed in older adults, and the prevalence of vertebral compression fracture (VCF) increases with age. We aimed to investigate the clinical outcomes of THA in patients with VCF.

METHODS

We reviewed the records of 453 patients who underwent THA at our institution between 2015 and 2021. We classified patients into those with and without VCF. VCF was identified using preoperative upright whole-spine radiographs. Spinal parameters, preoperative and 1-year postoperative clinical outcomes of the Harris hip score (HHS), Oxford hip score (OHS), and visual analog scale (VAS) for low back pain (LBP) were assessed. Furthermore, propensity score-matched cohorts for age, sex, body mass index, and spinal parameters were created, and the clinical outcomes were compared between the two groups.

RESULTS

Among the 453 patients, 51 (11.3%) with VCF and 402 without VCF were identified. Before matching, patients with VCF were older (p < 0.01), had sagittal spinal imbalance (p < 0.01), and had worse clinical outcomes pre- and postoperatively. After matching 47 patients in both groups, patients with VCF had worse HHS (p < 0.05), especially regarding support and distance walked, and worse VAS scores for LBP (p < 0.05) pre- and postoperatively. However, the improvements in scores were not significantly different between the groups.

CONCLUSIONS

HHS, especially regarding support and distance walked, and VAS scores for LBP were poorer in patients with VCF preoperatively and 1-year postoperatively. Our findings suggest that hip surgeons should evaluate not only spinal alignment but also the presence of VCF before performing THA.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

Mid-term low back pain improvement after total hip arthroplasty in 306 patients with developmental dysplasia of the hip

BACKGROUND

Low back pain (LBP) from hip and spinal disorders has been one of the main reasons for visiting physicians in patients with developmental dysplasia of the hip (DDH). It is essential to identify the LBP improvement among all grades of DDH patients treated with total hip arthroplasty (THA) at 5-year follow-up.

METHODS

The study included 407 hips of 306 patients (38 males, 268 females) who underwent THA between July 2007 and December 2016. There were 65 hips in Crowe I, 61 hips in Crowe II, 69 hips in Crowe III, and 212 hips in Crowe IV. One hundred and fourteen hips received subtrochanteric shortening. Patients included 101 bilateral THA (BTHA) and 205 unilateral THA (UTHA). The evaluation was performed through Back Pain Function Scale (BPFS), Harris hip score, Visual Analogue Scale (VAS), operative data and radiographic examinations.

RESULTS

The BPFS in patients of unilateral Crowe III and IV relieved significantly more (p < 0.05). However, the BPFS in patients with bilateral symmetry DDH hips relieved significantly less than other groups of DDH hips (p < 0.05). Harris in hips of Crowe II improved significantly more (p < 0.05). The VAS in hips of Crowe II and III improved significantly more (p < 0.05). The unilateral THA surgical time, blood loss, blood transfusion, and osteotomy number and length in Crowe IV were significantly more (p < 0.05).

CONCLUSION

THA is reliable to relieve LBP in DDH patients of unilateral Crowe III and IV; however, in patients with unilateral Crowe I, Crowe II, and bilateral DDH hips, the LBP improvements were limited. This should assist shared decision-making between orthopedic surgeons and patients.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Hip replacement improves lumbar flexibility and intervertebral disc height - a prospective observational investigation with standing and sitting assessment of patients undergoing total hip arthroplasty

PURPOSE

The pathogenic mechanism of the hip-spine syndrome is still poorly elucidated. Some studies have reported a reduction in low back pain after total hip arthroplasty (THA). However, the biomechanical mechanisms of THA acting on the lumbar spine are not well understood. The aim of the study is to evaluate the influence of THA on (1) the lumbar lordosis and the lumbar flexibility and (2) the lumbar intervertebral disc height.

METHODS

A total of 197 primary THA patients were prospectively enrolled. Pre- and post-operative biplanar stereoradiography was performed in standing and sitting positions. Spinopelvic parameters (lumbar lordosis (LL), pelvic tilt, sacral slope, pelvic incidence), sagittal spinal alignment (sagittal vertical axis, PI-LL mismatch (PI-LL)) and lumbar disc height index (DHI) for each segment (L1/2 to L5/S1) were evaluated. The difference between standing and sitting LL (∆LL = LL_standing - LL_sitting) was determined as lumbar flexibility. Osteochondrosis intervertebralis was graded according to Kellgren and Lawrence (0-4), and patients were assigned to subgroups (mild: 0-2; severe: 3-4).

RESULTS

Lumbar flexibility increased significantly after THA (pre: 22.04 ± 12.26°; post: 25.87 ± 12.26°; p < 0.001), due to significant alterations in LL in standing (pre: 51.3 ± 14.3°; post: 52.4 ± 13.8°; p < 0.001) and sitting (pre: 29.4 ± 15.4°; post: 26.7 ± 15.4°; p = 0.01). ∆LL increased significantly in both subgroups stratified by osteochondrosis (pre/post: ΔLL_mild: 25.4 (± 11.8)/29.4 ± 12.0°; p < 0.001; ΔLL_severe: 17.5 (± 11.4)/21.0 ± 10.9°; p = 0.003). The DHI increased significantly from pre-operatively to post-operatively in each lumbar segment. PI-LL mismatch decreased significantly after THA (pre: 3.5°; post: 1.4°; p < 0.001).

CONCLUSION

The impact of THA on the spinopelvic complex was demonstrated by significantly improved lumbar flexibility and a gain in post-operative disc height. These results illustrate the close interaction between the pelvis and the vertebral column. The investigation provides new insights into the biomechanical patterns influencing the hip-spine syndrome.

Spinopelvic alignment and low back pain after total hip arthroplasty: a scoping review

OBJECTIVE

Spinopelvic alignment is increasingly considered as an essential factor for maintaining an energy-efficient posture in individuals with normal or pathological status. Although several previous studies have shown that changes in the sagittal spinopelvic alignment may occur in patients undergoing total hip arthroplasty (THA), no review of this area has been completed so far. Thus, the objective of this scoping review was to summarize the evidence investigating changes in spinopelvic alignment and low back pain (LBP) following THA.

DATA SOURCES

We adhered to the established methodology for scoping reviews. Four electronic databases were systematically searched from inception-December 31, 2021.

STUDY SELECTION

We selected prospective or retrospective observational or intervention studies that included patients with THA.

DATA EXTRACTION

Data extraction and levels of evidence were independently performed using standardized checklists.

DATA SYNTHESIS

A total of 45 papers were included in this scoping review, involving 5185 participants with THA. Pelvic tilt was the most common parameter measured in the eligible studies (n = 26). The results were not consistent across all studies; however, it was demonstrated that the distribution of pelvic tilt following THA had a range of 25° posterior to 20° anterior. Moreover, decreased sacral slope and lower pelvic incidence were associated with increased risk of dislocation in patients with THA. Lumbar spine scoliosis did not change significantly after THA in patients with bilateral hip osteoarthritis (5.50°(1.16°) vs. 3.73°(1.16°); P-value = 0.29). Finally, one study indicated that LBP improvement was not correlated with postoperative changes in spinopelvic alignment parameters. Several methodological issues were addressed in this study, including no sample size calculation and no type-I error adjustment for outcome multiplicity.

CONCLUSIONS

Changes in spinopelvic alignment may occur after THA and may improve with time. Patients with a THA dislocation usually show abnormal spinopelvic alignment compared to patients without a THA dislocation. LBP usually improves markedly over time following THA.