Hip-spine Syndrome Research Articles

Preoperative Abnormal Posture Improves After Total Knee Arthroplasty: Knee–Hip–Spine Syndrome

BackgroundSpinal, pelvic, and lower extremity alignment is crucial for maintaining a healthy body posture. However, with aging, this posture becomes challenging to maintain due to muscle weakness and skeletal degeneration. Osteoarthritis (OA) of the hip and knee can also lead to abnormal posture, known as hip–spine and knee–spine syndrome. Total knee arthroplasty (TKA) can help relieve pain and improve lower extremity alignment. This may also improve abnormal posture, such as in knee–hip–spine syndrome. However, the condition of the contralateral knee may affect this improvement. This study evaluated the effects of TKA on clinical outcomes and radiographic body posture. MethodsPatients scheduled for primary one-sided TKA were divided into two groups: the unilateral group comprised patients who had contralateral knee OA conditions. The bilateral group included patients who had prior contralateral TKA. Knee range of motion (ROM), the Knee Injury and Osteoarthritis Outcome Score (KOOS), radiographic lateral femorotibial angle (FTA), hip and knee flexion angles, and sagittal vertical axis (SVA) while standing were measured 24 months after TKA. ResultsBoth groups showed improved knee extension, KOOS, and radiographical FTA and hip and knee flexion angles 24 months after TKA. The SVA also improved 6 months after TKA in both groups and was maintained in the bilateral group, while it deteriorated again in the unilateral group 24 months after TKA. ConclusionA TKA can improve abnormal body posture due to knee OA as in knee–hip–spine syndrome. However, the condition of a contralateral knee can affect TKA outcomes.

An alternative method for measuring patient’s sagittal balance parameters in sitting and standing positions

Introduction The understanding of the biomechanics of movements in the spinopelvic segment plays an important role in the successful treatment of patients with hip-spine syndrome. Analysis of the biomechanical processes occurring in the biokinematic chain of the spine–pelvis–hip during the transition from standing position to sitting position allows us to conclude that the acetabular axis of rotation of the pelvis in space is not the only one. Classical methods for measuring PI, PT, overhang S1 are applicable for patients in a standing position and use the hip joint as a starting point, since it is the point of rotation of the pelvis in space in a standing position. Previously, using mathematical modeling, we described spatial changes in the pelvis during a given change in the body position and showed the presence of a second point of pelvis rotation in space, which appears in a sitting position. We assumed that in a sitting position, it is necessary to use other methods for calculating indicators of spinopelvic relationships for their determination.Purpose of the study was to evaluate the parameters of patients’ sagittal balance using the proposed alternative method in standing and sitting positions.Materials and methods Medical documentation and the results of X-ray examination of 20 patients with unilateral idiopathic coxarthrosis who underwent total hip replacement surgery were analyzed. The radiographic parameters were calculated: PI, PT, overhang S1 in standing and sitting positions, anterior inclination of the acetabular component; parameters PI ischial, PT ischial, deviation of the ischial tuberosities in standing and sitting positions were proposed and calculated.Results The study shows that there is no statistical difference in the values of the angles PI standard for a standing position and PI ischial for a sitting position. It corresponds to objective data and is generally accepted. Examples of changes in radiographic parameters of the sacral slope and the deviation of the ischial tuberosities were shown reflecting the rotation of the pelvis in space through the second, ischial axis, that confirm the biaxial concept of pelvic rotation.Discussion The calculations demonstrated the possibility of using alternative indicators of spinopelvic relationships (PT, distance of overhang of the sacrum (overhang S1), deviation of the ischial tuberosities). They enabled assessment of the spatial transformation of the pelvis and the ability to predict the spatial position of the acetabulum, which is an important factor for successful treatment of patients with combined pathology of the hip joint and spine.Conclusion Our findings complement the biaxial concept of pelvic rotation. An alternative method for measuring sagittal balance parameters in a sitting position has been proposed. Further research is required to assess the practical significance of this method.

Hip-Spine and Knee-Spine Syndrome: Is Low Back Pain Improved After Total Hip and Knee Arthroplasty?

Hip and knee osteoarthritis (OA) and low back pain (LBP) are prevalent diseases that can negatively impact daily activities. The concurrent existence of lumbar spine disorders with hip or knee issues forms two syndromes: hip-spine syndrome (HSS) and knee-spine syndrome (KSS). The primary objective of this study is to evaluate the relationship between hip and knee OA and LBP, as well as the changes to LBP after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The secondary objective is to identify the cause of LBP among patients with hip and knee OA. The group of hip OA patients treated with THA consisted of 34 individuals, and the group of knee OA patients treated with TKA consisted of 45 individuals. In these two groups of patients, the LBP was assessed using the visual analog scale score preoperatively and four and 12 months postoperatively. To determine the cause of LBP, we compared preoperative and postoperative (12-month) pelvic obliquity and hip or knee pain in patients with and without preoperative LBP. For hip OA-THA, more than half (55.88%) of patients suffering from hip OA also experienced moderate to severe LBP. Improvement in LBP was noticed in 79% of these patients at both four and 12 months post-THA, with levels dropping from 6.84 to 2.58 and then 2.53, respectively. Moreover, improvements in hip pain and pelvic obliquity were observed in patient groups both with and without preoperative LBP following THA. This suggests that there's no obvious correlation between LBP and these parameters. For knee OA-TKA, most (62.22%) patients with knee OA experienced moderate to very severe LBP. In 50% of these patients, LBP showed improvement at four and 12 months post-TKA (6.39 → 4.79 → 4.04). Additionally, in both groups with and without preoperative LBP, knee pain and pelvic obliquity were improved after TKA, suggesting no clear association between LBP and these parameters. HSS and KSS were frequently observed in patients. A significant improvement in LBP was seen after THA or TKA, suggesting that total arthroplasty should be prioritized before spinal surgery. Furthermore, there is not a definitive link between LBP, joint pain, and pelvic obliquity.

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

BackgroundPostoperative 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).MethodsA 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.ResultsPatients 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).ConclusionPostoperative 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.

Hip-spine syndrome: Diagnostic difficulties

Introduction. Hip-spine syndrome (HSS) is a combination of coexisting hip osteoarthritis (OA) and degenerative lumbar spine stenosis (LSS). Main difficulties in treating patients with HSS are in early diagnostics and in choosing right surgery, because mistakes lead to pain maintenance. Existing diagnostic algorithms show right surgery choosing failure in 15–20%. We present results of examination patients with HSS in our survey.The aim – to present clinical and instrumental results of examination of patients with hip-spine syndrome.Materials and methods. We have examined 378 patients with typical pain pattern (buttocks, low back spine, groin and lateral hip) and difficulties in pain source definition. We performed hip X-rays and low back spine MRI.Due to results we divided patients into three groups – patients with HSS (n=100), with hip OA (n=172) and patients with LSS (n=106). We used Harris Hip Score, Oswestry Disability Index and Visual Analogue Score to determine hip and lumbar spine functional status and pain level.Results. Patients with HSS had higher (p&lt;0.05) pain levels (76.5±9.1 mm) than patients with hip (68.3±7.9 mm) or lumbar spine pathology (67.4±7.9 mm). Harris Hip Score in patients wirh HSS (52.7±8.1 points) was same as in patients with hip OA (55.5±9.1 points), Oswestry Disability Index in these patients (44.2±7.6%) was same as in patients with LSS (43.2±7.8%).Conclusion. High pain level and low Harris Hip Score and Oswestry index, along with clinical examination, on first visit can help suspect hip-spine syndrome and recommend both hip and lumbar spine imaging.

Change of Symptoms after Total Hip Arthroplasty in Patients with Hip-Spine Syndrome.

Elderly patients with degenerative diseases undergo treatment for the hip and spine; these patients present with various symptoms. This study focused on patients with residual symptoms, predominantly pain, even after receiving treatment for their spinal lesions. Patients who underwent total hip arthroplasty (THA) between 2016 and 2022 at a single tertiary hospital were included in the study. Of the 417 patients who underwent primary THA, a retrospective review of 40 patients with previous lesions of the spine was conducted. Patients were stratified to two cohorts: Patients with symptoms related to the spine (Group A), and those with hip-related symptoms (Group B). Pre- and postoperative comparisons of groups A and B were performed. Improvements in patients' symptoms were observed in groups A and B after THA. In Group A, the mean preoperative visual analog scale (VAS) score was 5.10±0.876, which showed a postoperative decrease to 2.70±1.767. In Group B, the mean preoperative VAS score was 5.10±1.539, which showed a postoperative decrease to 2.67±1.493. According to the findings, promising results were achieved with THA in treatment of debilitating diseases of the hip for both the prognosis of the disease, as well as the patients' symptoms. In addition, in some cases elderly patients with dual pathologies underwent treatment for spinal lesions without performance of any evaluation related to the hip. Thus, evaluation of a patient's hip must be performed and performance of THA in patients with symptoms even after treatment of spinal lesions is recommended.

Association Between Osteoarthritis Burden and Intervertebral Disk Degeneration in Patients Undergoing Lumbar Spine Surgery for Degenerative Lumbar Spondylolisthesis.

A retrospective analysis of prospectively collected data. To assess the association between intervertebral disk degeneration and hip and knee osteoarthritis (OA) in patients with degenerative lumbar spondylolisthesis. The co-occurrence of hip OA and degenerative spinal pathologies was first described as the "hip-spine syndrome" and has also been observed in knee OA. It remains unclear whether both pathologies share an underlying connection beyond demographic factors. Intervertebral disk degeneration was classified by the Pfirrmann Classification and intervertebral vacuum phenomenon. Intervertebral vacuum phenomenon was classified into mild (1 point), moderate (2 points), and severe (3 points) at each level and combined into a lumbar vacuum score (0-15 points). Similarly, a lumbar Pfirrmann grade was calculated (5-25 points). Patients with previous hip or knee replacement surgery were classified as having an OA burden. We used multivariable regression to assess the association between OA and disk degeneration, adjusted for age, body mass index, and sex. A total of 246 patients (58.9% female) were included in the final analysis. Of these, 22.3% had OA burden. The multivariable linear regression showed an independent association between OA burden and lumbar vacuum (β = 2.1, P <0.001) and Pfirrmann grade (β = 2.6, P <0.001). Representing a 2.1 points higher lumbar vacuum and 2.6 points higher lumbar Pfirrmann grade after accounting for demographic differences. Our study showed that OA burden was independently associated with the severity of the intervertebral disk degeneration of the lumbar spine. These findings give further weight to a shared pathology of OA of large joints and degenerative processes of the lumbar spine. 3.

Response to Letter to the Editor by Fukuda et al regarding Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

Response to Letter to the Editor by Fukuda et al regarding Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

Hip-spine syndrome in adult spinal deformity patients

With the increasing prevalence of hip-spine syndrome, it is crucial to appreciate the biomechanical interplay between hip and spine degeneration or deformity and the consequential compensatory changes. Adult spinal deformity (ASD) patients are uniquely affected as a concomitant hip osteoarthritis (HOA) may impact their baseline and postoperative sagittal alignment. Similarly, severe HOA patients undergoing total hip replacement with concomitant spinal deformity may require personalized surgical planning for the placement of their acetabular component. If surgical intervention is required in ASD patients, the authors’ preferred sequence is to perform spinal realignment first. If major realignment is not planned, we recommend treating the most symptomatic pathology. Further investigation is required to evaluate the impact of hip pathology on radiographic and patient-reported outcomes following ASD surgery and vice versa.

Study of the stress-strain state of the posterior lumbar fusion models in case of normal indicators of the sagittal balance of the spine and pelvis

Background. Patients suffering from hip-spine syndrome with significant changes in the hip joint complain of pain in the lumbar spine in 21.2–49.4 % of cases. After performing lumbar fusion, the mobility of the pelvis decreases, which leads to an increased risk of dislocations and the development of impingement after hip arthroplasty that is the cause for repeated surgical interventions. Goal: to study the stress distribution in the models of posterior lumbar fusion in case of normal values of the sagittal contour of the spine and lumbar lordosis. Materials and methods. A finite-element model has been developed reflecting the condition that occurs in the combined course of degenerative diseases of the lumbar spine and hip joint and is characterized by normal lordosis of 40º and forward body tilt due to flexion contracture in the hip joints. The following options were modeled: 1 — posterior fusion of the L4-L5 vertebrae using a transpedicular structure with 4 screws and an interbody support; 2 — posterior fusion of the L3-L4-L5 vertebrae using a transpedicular construction with 6 screws; 3 — posterior fusion of L1-L5 vertebrae using a transpedicular structure with 10 screws. When conducting the research, the values of stresses in the Th1-L5 vertebrae, on the screws and rods of the transpedicular structure were studied. Results. Posterior fusion with a transpedicular construction on two L4-L5 vertebrae leads to the occurrence of maximum stresses in vertebral bodies of the lumbar spine, especially L4-L5. The lowest stresses in the lumbar vertebral bodies can be obtained when the transpedicular structure is applied to all 5 vertebrae. The use of all options for posterior fusion, except for the 4-screw scheme, allows to reduce the stress in the vertebral arches of the lumbar spine below the level of the normal spine model, except for the L1 vertebra. This leads to an increase in the level of stress from the Th6 to Th12 vertebrae. The construction placed on all 5 vertebrae ensures the lowest level of stress in the arches of thoracic vertebrae. The construction placed on all the vertebrae of the lumbar spine provides a minimum level of stress in the bone tissue around the fixing screws. Reducing the length of fixation leads to a significant increase in stress in these zones. With all types of installation of the transpedicular construction, the values of the stresses on the screws in the L3-L5 vertebrae are comparable. When using the design for 5 vertebrae of the lumbar spine, the locking screws in the L1 and L2 vertebrae will experience significant loads, which, accordingly, will cause significant stress in them. The maximum level of stress in the rods occurs when two L4-L5 vertebrae are instrumented, the minimum is when the structure is placed on all five vertebrae of the lumbar spine. Conclusions. Given the stress distribution, the length of fixation plays an important role: the longer the length of fixation, the lower the stress level, both in the bone elements of the model and in the elements of metal structures.

Spinal fusion and total hip arthroplasty: why timing is important.

There is increasing debate among orthopaedic surgeons over the temporal relationship between lumbar spinal fusion (LSF) and total hip arthroplasty (THA) for patients with hip-spine syndrome. Few large studies have directly compared the results of patients who undergo LSF prior to THA (LSF-THA) to those who undergo LSF after THA (THA-LSF). The current study matched THA patients with a prior LSF to patients who underwent LSF after THA to assess: 90-day and 1-year (1) medical/surgical complications; and (2) revisions. We queried a national, all-payer database to identify all patients undergoing THA between 2010 and 2018 (n = 716,084). The LSF-THA patients and THA-LSF patients were then matched 1:1 on age, sex, Charleson Comorbidity Index, and obesity. Medical/surgical complications and revisions at 90 days and 1 year were recorded. Categorical and continuous variables were analysed utilising t-tests and chi-square, respectively. LSF-THA patients experienced significantly more postoperative dislocations at 90 days and 1 year compared to THA-LSF patients (p = 0.048 and p < 0.001). There were a similar number of revisions performed for LSF-THA and THA-LSF patients at both 90 days and 1 year (p = 0.183 and p = 0.426). Furthermore, at 1 year, LSF-THA patients experienced more pneumonia (p = 0.005) and joint infection (p = 0.020). Prior LSF has been demonstrated to increase the risk of postoperative dislocation in patients undergoing THA. The results of the present study demonstrate increased dislocations with LSF-THA compared to THA-LSF. For "hip spine syndrome" patients requiring both LSF and THA, it may be more beneficial to undergo THA prior to LSF. Arthroplasty surgeons may wish to collaborate with spinal surgeons to ensure optimal outcomes for this group of patients.

Letter to the Editor Concerning "Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients with Hip-Spine Syndrome," by Chen et al.

Letter to the Editor Concerning "Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients with Hip-Spine Syndrome," by Chen et al.

Poster 220: Outcomes of Hip Arthroscopy in Patients with Hip-Spine Syndrome: A Matched-Pair Controlled Study with Minimum Two-Year Follow-Up

Objectives: Hip–spine syndrome is a phenomenon commonly seen in the geriatric population presenting with concurrent hip osteoarthritis and lumbar spine degenerative disease. Secondary hip-spine syndrome can develop when compensatory stresses are placed on the lumbosacral spine due to pathologies that limit hip range of motion, such as femoroacetabular impingement (FAI). The literature remains conflicted on the impact of hip arthroscopy in hip-spine syndrome and there is a paucity of studies that report long term outcomes. The purpose of this study was to conduct a matched-pair analysis to assess the effects of lumbar spine pathology on minimum two-year clinical outcomes of patients undergoing hip arthroscopy for FAI. Methods: An institutional review board-approved retrospective review of a prospectively collected, single-surgeon database was performed to identify patients who underwent hip arthroscopy for FAI with evidence of concomitant lumbar spine pathology. Importantly, all patients participated in the same postoperative protocol and underwent capsular management via the previously published puncture capsulotomy technique. Additionally, included patients had failed conservative treatment, a minimum of two-year follow-up, and symptoms of low back pain with objective evidence of lumbar pathology (i.e., herniation, degenerative disc disease, stenosis, spondylosis, etc.) at the time of surgery. Patients were excluded if they had any previous hip surgery, evidence of hip dysplasia (lateral center edge angle ≤25°), or advanced osteoarthritis (Tönnis ≥2). Patients in the hip-spine (HS) cohort were matched 1:1 by age within 5 years, body mass index (BMI) within 5.0 kg/m2, and sex to a matched control (MC) cohort. The MC cohort lacked subjective or objective evidence of lumbar spine pathology. The following patient- reported outcomes (PROs) were recorded in each cohort: Modified Hip Harris Score (mHHS), International Hip Outcome Tool-33 (iHOT-33), Non-Arthritic Hip Score (NAHS), rates of revision arthroscopy, and conversion to total hip arthroplasty (THA). Results: A total of 60 patients with lumbar disease (HS; age = 39.5 ±10.2, BMI = 26.3 ±4.0, 48.3% Female) were matched with 60 control patients (MC; age = 39.4 ±11.6, BMI = 25.7 ±4.1, 48.3% Female). At baseline, all PROs were significantly lower in the HS cohort (all p&lt;0.05). At one-year follow-up, the HS cohort exhibited a greater magnitude of improvement in all PROs, with significant differences in the NAHS (p = 0.006). Additionally, a higher percentage of patients in the HS cohort achieved the minimal clinically important difference (MCID) threshold for all outcome measures at one-year, and a significant difference was identified in the NAHS (p = 0.026; Tables 1&amp;2). At two-year follow-up, all PROs were significantly lower in the HS cohort (all p&lt;0.05), however at three- and five-year follow-up no differences were identified between cohorts in mean PROs, magnitude of improvement, or percentage of patients achieving MCID thresholds (all p&gt;0.05). No significant differences in the rates of revision (0% vs. 0%) or conversion to THA (5.3% vs. 3.4%) were identified between cohorts (all p&gt;0.99). Conclusions: While patients with a history of lumbar spine pathology achieved lower short-term outcomes after hip arthroscopy, these differences were mitigated when follow-up was expanded to 3- and 5- years (Figure 1). While the HS cohort exhibited lower baseline PROs at the time of surgical intervention, these patients had an equal or greater magnitude of improvement across all time points. This study’s findings have implications for the shared decision-making process and managing patient expectations prior to undergoing hip arthroscopy for FAI. Although it may take greater than two years, patients with hip-spine syndrome can attain clinically meaningful improvement in hip function following hip arthroscopy for FAI. [Table: see text][Table: see text]

Outcomes of Hip Arthroscopy in Patients with Hip-Spine Syndrome: A Matched Control Study with Minimum 2-Year Follow-Up

Outcomes of Hip Arthroscopy in Patients with Hip-Spine Syndrome: A Matched Control Study with Minimum 2-Year Follow-Up

Seeking answers through the pain

This article tells the story of the history and outcome of a 64-year-old woman who had suffered pain and other symptoms for over a decade. The woman thought nothing could be done to help her condition. The procedure that was eventually undertaken brought about a huge transformation in pain reduction and helped with mobility and posture. This operation came into being in relatively recent times and has revolutionised the treatment of people with hip-spine syndrome. The technique called an in-situ arthroplasty operation allows accurate restoring of leg length, together with restoring the natural alignment of hip structures.

Does Order of Operation Matter in Patients Who Have Concomitant Hip and Spine Pathology?

BackgroundIn patients, who have coexisting lumbar spine and degenerative hip disease, there remains uncertainty regarding whether hip or spine surgery should be performed first. We hypothesized that undergoing total hip arthroplasty (THA) would protect against subsequent lumbar spine surgery (LSS) in patients who have ‘hip-spine syndrome.’ MethodsA retrospective cohort study was performed from 2013 to 2021 on patients who had radiographically–confirmed hip osteoarthritis and degenerative lumbar spine pathology, evaluated separately in spine and arthroplasty clinics prior to surgical intervention. Included patients ultimately underwent THA and/or LSS. The primary outcome was survivorship free of LSS or THA after the other was initially performed. ResultsOf 256 patients, 206 (80.5%) underwent THA first. Only 14 of 206 (6.8%) who underwent THA required subsequent LSS, while 31 of 50 (62%) who underwent LSS required subsequent THA, (P < .001). At 5 years, there was 93.9% survivorship-free of LSS in the THA first group, compared to 44.7% survivorship-free of subsequent THA in the LSS group. Multivariate analyses showed that patients who had THA first had lower odds of undergoing subsequent surgery (odds ratio [OR]: 0.61, CI: 0.52-0.70, P < .001) compared to those who underwent LSS first. Additionally, those who have higher initial Kellgren-Lawrence grade hip osteoarthritis had lower odds (OR: 0.94, CI: 0.89-0.99, P = .04), and those who have progressive neurologic deficits (OR: 2.64, CI: 1.89-3.7, P < .001) and neurogenic claudication (OR: 1.15, CI: 1.06-1.24, P = .001) had increased odds of undergoing subsequent LSS. ConclusionPatients with ‘hip-spine syndrome’ may receive more initial benefit from undergoing THA, potentially reducing the subsequent need for LSS. The exceptions were those patients who had lower-severity hip osteoarthritis and symptoms of major spinal stenosis.

Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

Prospective cohort. Determine if total hip arthroplasty (THA) changes lumbar spine kinematics during gait in a manner that explains the improvements in back pain seen in patients with hip-spine syndrome. For patients with hip-spine syndrome, improvements in both hip and back pain have been demonstrated after THA; however, the exact mechanism of improvement in back pain remains unknown, as no corresponding changes in lumbar spine static radiographic parameters have been identified. Thirteen patients with severe, unilateral hip osteoarthritis scheduled to undergo THA with concomitant back pain and disability were tested at baseline and 6 months after THA. Harris Hip Score (HHS) and Oswestry Disability Index questionnaires were completed; the static orientation of the spine and pelvis were measured on standing radiographs, and lumbar spine kinematics were measured during treadmill walking using a validated measurement system that matched subject-specific bone models created from CT scans to dynamic biplane radiographs. After THA, both the Oswestry Disability Index (36.3-11.3, P <0.001) and Harris Hip Score (55.7-77.9, P <0.001) improved; however, there were no changes in static intervertebral or pelvis orientation. During gait after THA, the overall lumbar spine (L1 to L5) was less lordotic from heel strike to contralateral toe off ( P <0.001), the L4 and L5 vertebra were less anteriorly tilted by 3.9° ( P =0.038) from midstance to contralateral heel strike and by 3.9° ( P =0.001) during stance, respectively. The decreased anterior tilt of the 2 lowest lumbar vertebrae and the corresponding loss of lumbar lordosis may reduce facet loading during the stance phase of gait after THA. This change in lumbar spine kinematics during gait is a potential mechanism to explain the observed improvements in back pain and disability after THA. 4.

Hip–Spine Syndrome: A Focus on the Pelvic Incidence in Hip Disorders

Since Offierski and MacNab reported a close association between the hip and spine as hip-spine syndrome in 1983, many studies on spinal alignment in hip disorders have been conducted. Notably, the pelvic incidence angle (PI) is the most important parameter and is determined by the anatomical variations in the sacroiliac joint and hip. Studies on the association of the PI with hip disorders can help in understanding the pathophysiology of hip-spine syndrome. A PI increase has been observed during the evolution of bipedal locomotion in humans and in the acquisition of gait during child development. Although the PI is a fixed parameter that is stable and unaffected by posture from adulthood onwards, it has become clear that it increases in the standing position in older people. While it may be associated with a greater risk of developing or progressing to spinal disorders, the association between the PI and hip disorders remains controversial because of the multifactorial nature of hip osteoarthritis (HOA) and the wide range of PIs in HOA (18-96°), making the interpretation of results difficult. However, several hip disorders (i.e., femoroacetabular impingement and rapid destructive coxarthrosis) have been shown to be associated with the PI. Further investigation on this topic is, therefore, warranted.

Hip-spine syndrome: A contemporaneous double surgery

Hip-spine syndrome: A contemporaneous double surgery

ASD with high pelvic retroversion develop changes in their acetabular orientation during walking

IntroductionIt was hypothesized that pelvic retroversion in Adult Spinal Deformity (ASD) can be related to an increased hip loading explaining the occurrence of hip-spine syndrome. Research questionHow pelvic retroversion can modify acetabular orientation in ASD during walking? Methods89 primary ASD and 37 controls underwent 3D gait analysis and full-body biplanar X-rays. Classic spinopelvic parameters were calculated from 3D skeletal reconstructions in addition to acetabular anteversion, abduction, tilt, and coverage. Then, 3D bones were registered on each gait frame to compute the dynamic value of the radiographic parameters during walking. ASD patients having a high PT were grouped as ASD-highPT, otherwise as ASD-normPT. Control group was divided in: C-aged and C-young, age matched to ASD-hightPT and ASD-normPT respectively. Results25/89 patients were classified as ASD-highPT having a radiographic PT of 31° (vs 12° in other groups, p ​< ​0.001). On static radiograph, ASD-highPT showed more severe postural malalignment than the other groups: ODHA ​= ​5°, L1L5 ​= ​17°, SVA ​= ​57.4 ​mm (vs 2°, 48° and 5 ​mm resp. in other groups,all p ​< ​0.001). During gait, ASD-highPT presented a higher dynamic pelvic retroversion of 30° (vs 15° in C-aged), along with a higher acetabular anteversion of 24° (vs 20°), external coverage of 38° (vs 29°) and a lower anterior coverage of 52° (vs 58°,all p ​< ​0.05). ConclusionASD patients with severe pelvic retroversion showed an increased acetabular anteversion, external coverage and lower anterior coverage during gait. These changes in acetabular orientation, computed during walking, were shown to be related to hip osteoarthritis.