Lumbosacral Transitional Vertebrae Predict Inferior Patient-Reported Outcomes After Hip Arthroscopy

Concomitant Ipsilateral Knee Pain Is Associated With Worse Preoperative Functional Status and Short-Term Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement Syndrome

PURPOSE

(1) To determine the effect of concomitant ipsilateral knee pain (IKP) on short-term outcomes after hip arthroscopic treatment of femoroacetabular impingement syndrome (FAIS) and (2) to determine whether IKP would improve with surgery.

METHODS

Data between September 2021 and May 2022 were reviewed. Patients with a diagnosis of FAIS who underwent hip arthroscopy with a minimum of 1-year follow-up were included. The exclusion criteria were prior ipsilateral hip or knee surgery, hip Tönnis grade greater than 1, knee Kellgren-Lawrence grade greater than 2, hip conditions (avascular necrosis, Legg-Calvé-Perthes disease, pigmented villonodular synovitis, osteoid osteoma, synovial chondromatosis, and developmental dysplasia of the hip), and spine diseases. All patients underwent knee magnetic resonance imaging preoperatively. Preoperative and short-term (1-year) patient-reported outcomes were collected, consisting of the Hip Sports Activity Scale score, weekly sports participation, modified Harris Hip Score (mHHS), 12-component International Hip Outcome Tool (iHOT-12) score, and visual analog pain scale (VAS) scores for the hip and the ipsilateral knee. The percentages of patients achieving the minimal clinically important difference and patient acceptable symptom state (PASS) for the mHHS and iHOT-12 score were calculated. Multivariate regression analysis was performed to determine the effect of IKP severity on postoperative outcomes. Subgroup analysis was performed between patients with IKP alleviation and those without IKP alleviation.

RESULTS

Among the 107 patients included, 47 presented with preoperative IKP. Compared with patients without IKP, the IKP cohort had comparable knee structural abnormalities (all with P > .05). Still, the IKP cohort showed inferior preoperative values for the mHHS (P = .003), iHOT-12 score (P = .016), hip VAS score (P = .001), and weekly sports participation (P = .039). Postoperatively, the IKP cohort had a lower mHHS (P = .046), lower iHOT-12 score (P = .037), and lower hip VAS score (P = .003) and were less likely to achieve the PASS for the mHHS (P = .021) and iHOT-12 score (P = .049). Patients with higher knee VAS scores were less likely to achieve the PASS for the mHHS (odds ratio, 0.61; P = .023). Within the IKP group, the knee VAS score improved from 2.3 to 1.0 (P < .001). Patients with alleviated IKP showed superior postoperative iHOT-12 scores (P = .038) compared with patients with persistent IKP.

CONCLUSIONS

Concomitant IKP at baseline negatively affected preoperative status and short-term clinical outcomes after arthroscopic treatment of FAIS. Patients with IKP were less likely to meet clinical thresholds. Most patients achieved IKP alleviation postoperatively, which was associated with superior clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Over 50% of Studies Report Low-Back Pain Is Associated With Worse Outcomes After Hip Arthroscopy When Compared With a Control Group: A Systematic Review

PURPOSE

To review outcomes of patients with low-back pathology undergoing primary hip arthroscopy for the treatment of femoroacetabular impingement (FAI) syndrome.

METHODS

The PubMed, Cochrane Trials, and Scopus databases were queried in June 2022 to conduct this systematic review using the following terms: ("hip" OR "femoroacetabular impingement") AND ("arthroscopy" OR "arthroscopic") AND ("spine" OR "lumbar" OR "sacral" OR "hip-spine" OR "back") AND ("outcomes"). Articles were included if they reported on patient-reported outcomes (PROs) and/or clinical benefit of patients undergoing hip arthroscopy with concomitant low-back pathology. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria. Case reports, opinion articles, review articles, and technique articles were excluded from this study. Forest plots were created to analyze preoperative and postoperative outcomes among patients with low-back pathology.

RESULTS

Fourteen studies were included in the review. There were 750 hips with low-back pathology and FAI (hip-spine syndrome) and 1,800 hips with only FAI (no hip-spine syndrome). All 14 studies reported PROs. In 4 studies in the group with hip-spine syndrome and 8 studies in the group with FAI without low-back pathology, the respective cohorts were reported to achieve the minimal clinically important difference in at least 1 PRO at a rate of 80%. Eight studies reported that patients with low-back pathology were associated with inferior outcomes or clinical benefit compared with patients without low-back pathology.

CONCLUSIONS

Patients undergoing primary hip arthroscopy with concomitant low-back pathology can expect favorable outcomes, but outcomes are superior in patients undergoing hip arthroscopy for FAI alone compared with FAI with concomitant low-back pathology.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to Level IV studies.

Editorial Commentary: Restrictions in Spinal Motion Result in Lower Outcome Scores After Hip Arthroscopy

The critical consideration in determining the efficacy of hip surgery is patient-reported outcomes, specifically the achievement of the clinical threshold. Several studies examined the achievement of the clinical threshold following hip arthroscopy (HA) in the presence of coexisting lumbar spine disease. The condition related to the spine receiving a lot of focus in recent research is the lumbosacral transitional vertebrae (LSTV). However, this condition could be just the tip of the iceberg. To forecast the outcomes of HA, it is far more important to comprehend spinopelvic motion. Since higher-grade LSTV is associated with less lumbar spine flexibility and reduces the ability to antevert acetabulum, it is possible that LSTV severity or grading could be one of the indicators of less effective operation "especially in "hip users"' (hip users are defined as patents who are more dependent on on hip motion than spinal motion). In light of this, lower-grade LSTV ought to have a less significant impact on surgical outcomes than higher-grade LSTV.

The Outcome of Hip Arthroscopy in the Setting of Lumbar Spine Disease Is Beneficial, Yet Limited: A Systematic Review of Existing Evidence

PURPOSE

To compare hip arthroscopy outcomes in femoroacetabular impingement (FAI) patients with concurrent symptomatic lumbar spine disease to the outcomes of arthroscopic FAI patients without spine disease.

METHODS

A systematic review was performed according to PRISMA guidelines via PubMed, Cochrane, Embase, and Google Scholar databases. Studies were valid for inclusion if they had an average follow-up ≥12 months and compared patient-reported outcome measures (PROMs) in hip arthroscopy patients with and without concurrent spinal disease. Data collected included study characteristics, patient demographics, follow-up intervals, surgical indications, spinal pathology, PROMs, and reoperation rates.

RESULTS

Twelve studies were included in this systematic review. 3,107 patients who underwent hip arthroscopy were evaluated: 1,056 with coexisting lumbar spine disease (spine cohort) and 2,051 control subjects without spine disease (control cohort). The average follow-up period was 24 months. Across included studies, there were 35 instances wherein postoperative PROM scores reported by each cohort were compared. In all 35 instances, the spine cohort reported inferior postoperative PROM scores with the difference being significant (P < .05) on 23 PROMs. Collectively, 23 cases were available contrasting the proportion of each cohort to achieve the minimal clinically important difference (MCID). In 22 (95.65%) of these cases, the spine cohort achieved the MCID at a lower rate than the control cohort. There were 14 PROMs, wherein intragroup analyses were reported that compared the preoperative and postoperative score reported by the spine cohort. On all 14 PROMs, the spine cohort reported significant (P < .05) improvement after arthroscopic intervention.

CONCLUSION

FAI patients with coexisting lumbar spine pathology experience significant improvement from baseline state after arthroscopic intervention. However, the postoperative outcomes reported are inferior, and the improvement from arthroscopy was limited when compared to surgical control subjects with FAI and normal spinal anatomy.

LEVEL OF EVIDENCE

Level IV: systematic review of Level II, III, and IV studies.

Relationship between Spinopelvic Parameters and Hip Function in Patients with Femoroacetabular Impingement at Diagnosis: A Cross-Sectional Study

Purpose

The aim of this study was to determine correlation between the spinopelvic parameters in sitting and standing positions (sacral slope [SS], lumbar lordosis [LL], spinopelvic tilt [SPT], pelvic incidence [PI], and pelvic femoral angle [PFA]), with hip function assessed using the modified Harris hip scores (mHHs) in patients with symptomatic femoroacetabular impingement (FAI) at diagnosis.

Materials and Methods

A retrospective study of 52 patients diagnosed with symptomatic FAI was conducted. Evaluation of the spinopelvic complex in terms of SS, LL, SPT, PI and PFA was performed using lateral radiographs of the pelvis and lumbosacral spine in standing and sitting positions. Assessment of hip function at diagnosis was performed using the mHHs. Calculation of spinopelvic mobility was based on the difference (Δ) between measurements performed in standing and sitting position.

Results

The median time of pain evolution was 11 months (interquartile range [IQR], 5-24 months) with a median mHHs of 66.0 points (IQR, 46.0-73.0) at diagnosis. The mean change of LL, SS, SPT, and PFA was 20.9±11.2°, 14.2±8.6°, 15.5±9.0°, and 70.7±9.5°, respectively. No statistically significant correlation was observed between spinopelvic parameters and the mHHs (P>0.05).

Conclusion

Radiological parameters of the spinopelvic complex did not show correlation with hip function at the time of diagnosis in patients with symptomatic FAI. Conduct of further studies will be required in the effort to understand the effect of the spinopelvic complex and its compensatory mechanics, primarily between the hip and spine, in patients with FAI before and after hip arthroscopy.

Patients With Low-Grade Lumbosacral Transitional Vertebrae Demonstrate No Difference in Achievement of Clinical Thresholds After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

PURPOSE

To compare clinical outcomes at 2 years following primary hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) between patients with and without low-grade lumbosacral transitional vertebra (LSTV).

METHODS

We performed a retrospective matched-cohort analysis of patients who underwent primary HA for FAIS from 2011 to 2018 with minimum 2-year follow-up. LSTV was graded on preoperative radiographs using the Castellvi classification. Patients with grades I and II LSTV were matched 1:1 with controls on age, sex, and body mass index. Radiographic markers of FAIS morphology were measured. Pre- to postoperative improvement in the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) as well as 2-year achievement rates for the minimum clinically-important difference, substantial clinical benefit, and patient acceptable symptom state were compared between patients with versus without LSTV. The Wilcoxon signed-rank test was used for intergroup mean comparisons and the Cochran-Mantel-Haenszel test for categorical variables.

RESULTS

In total, 58 patients with LSTV were matched to 58 controls. Among LSTV patients, 48 were Castellvi type 1 (82.8%) and 32 (55.2%) had bilateral findings. No significant differences were found between groups with respect to radiographic markers of FAIS, including alpha angle (P = .88), lateral center edge angle (P = .42), or crossover sign (P = .71). Although patients with LSTV had greater improvement in NAHS at 2-year follow-up compared with control patients (P = .04), there were no significant differences in modified Harris Hip Score improvement (P = .31) or achievement of the minimum clinically-important difference (P = .73), substantial clinical benefit (P = .61), or patient acceptable symptom state (P = .16).

CONCLUSIONS

Patients with low-grade LSTV had greater 2-year improvement in NAHS than controls, whereas no significant differences were observed in achievement of clinical thresholds at 2-year follow-up. There were no differences between groups with respect to any measured radiographic markers of FAIS morphology. Importantly, the findings of this study are underpowered and should be viewed with caution in the greater context of the LSTV literature.

LEVEL OF EVIDENCE

III; retrospective comparative study.

Prevalence of Lumbosacral Transitional Vertebral Anomalies Among Healthy Volunteers and Patients with Hip Pathology: Association with Spinopelvic Characteristics

A lumbosacral transitional vertebra (LSTV) has been reported to be prevalent among patients with hip dysplasia. The aims of this study were to determine the (1) prevalence of an LSTV in young patients presenting with hip pain and a group of asymptomatic volunteers, (2) effect of an LSTV on spinopelvic characteristics, and (3) presence of low back pain among patients with an LSTV.

Methods

This cross-sectional study included 102 patients with hip pathology and 51 asymptomatic volunteers (mean age, 33.9 ± 7.3 years; mean body mass index, 26.0 ± 5.0 kg/m2; 57.5% female). Participants underwent radiographic assessment of the lumbar spine and pelvis in standing and deep-seated positions. LSTV occurrence was classified according to the Castellvi system. Spinopelvic characteristics included lumbar lordosis (including segmental lumbar angles), pelvic tilt, and hip flexion (pelvic-femoral angle). Differences between standing and deep-seated values were calculated. Low back pain was assessed using the Oswestry Disability Index.

Results

The prevalence of LSTV type ≥II was 8.5%, with no difference between patients and volunteers (p = 0.386). Individuals with an LSTV had a greater standing L1-L5 angle (mean, 51.6° ± 11.7° versus 38.9° ± 9.3°; p < 0.001). The overall spinal flexion (change in L1-S1 angle between the standing and deep-seated positions) in individuals with an LSTV was similar to that in individuals without an LSTV; restricted L5-S1 mobility was compensated for at L1-L2 (10.2° ± 5.8° in those with versus 8.4° ± 4.1° in those without an LSTV; p = 0.070). No significant difference in the presence of low back pain was found (p = 0.250).

Conclusions

An LSTV was found in 8.5% of young adults, with no difference between patients with hip pathology and controls. Individuals with an LSTV have greater standing lumbar lordosis, with altered mechanics at the cephalad adjacent level, which may predispose these individuals to degenerative changes at this level.

Level of Evidence

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

Hip Spine Syndrome Negatively Impacts Arthroscopic Outcomes in the Management of Femoroacetabular Impingement Syndrome: A Systematic Review

To determine whether the presence of spine pathology affects clinical outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) in the setting of hip-spine syndrome (HSS) METHODS: A systematic review of PubMed and Cochrane was conducted. Primary research articles evaluating patient-reported outcomes (PRO) after hip arthroscopy for FAIS in the presence of concomitant spine pathology were considered RESULTS: Literature review identified 12 studies meeting criteria. In 2109 FAIS patients undergoing hip arthroscopy, 591 had concomitant spine pathology. Baseline PROs in the hip-spine (modified Harris Hip Score [mHHS]: 39.8-65.29 vs 56.9-78.8, 8 studies; non-arthritic hip score [NAHS]: 42.2-51.5 vs 68.2-75.2, 4 studies; hip outcome score-activities of daily living [HOS-ADL]: 45.9-71.1 vs 49.3-89.51, 9 studies; hip outcome score-Sport (HOS-Sport): 22.8-49.6 vs 50.6-73.1, 3 studies; international hip outcome tool-33 [iHOT-12]: 38.0 vs 66.0, 1 study; visual analog scale [VAS] Pain: 6.43-6.56 vs 1.18-3.60, 3 studies; VAS Satisfaction: 7.18-7.46 range at follow-up, 2 studies) and control (mHHS: 39.3-64.9 vs 70.2-92.6, 6 studies; NAHS: 42.8-54.2 vs 74.0-87.1, 4 studies; HOS-ADL: 59.0-76.4 vs 75.4-97.1, 4 studies; HOS-Sport: 38.1-55.1 vs 60.9-93.9, 3 studies; iHOT-12: 43.4 vs 89.8, 1 study; VAS Pain: 6.18-6.22 vs 1.82-3.44, 2 studies; VAS Satisfaction: 7.74-8.22 range at follow up, 2 studies). Minimal clinically important difference threshold rates achieved in the hip-spine (44.1-86.7, 4 studies) cohorts were significantly lower than control (79.4-88.2%; 4 studies) cohorts in 3 studies. Patient-acceptable symptomatic state threshold rates achieved in the hip-spine (42-63.5, 3 studies) cohorts were significantly lower than control (58.8-81.0, 3 studies) in 1 study. There was no statistical difference in complication and reoperation rates between cohorts CONCLUSION: FAIS patients with concomitant HSS have improved but inferior outcomes after hip arthroscopy compared to patients without HSS LEVEL OF EVIDENCE: IV, systematic review.

Evaluation of additional causes of hip pain in patients with femoroacetabular impingement syndrome

Femoroacetabular impingement syndrome (FAIS) is an increasingly prevalent pathology in young and active patients, that has contributing factors from both abnormal hip morphology as well as abnormal hip motion. Disease progression can be detrimental to patient quality of life in the short term, from limitations on sport and activity, as well as the long term through early onset of hip arthritis. However, several concurrent or contributing pathologies may exist that exacerbate hip pain and are not addressed by arthroscopic intervention of cam and pincer morphologies. Lumbopelvic stiffness, for instance, places increased stress on the hip to achieve necessary flexion. Pathology at the pubic symphysis and sacroiliac joint may exist concurrently to FAIS through aberrant muscle forces. Additionally, both femoral and acetabular retro- or anteversion may contribute to impingement not associated with traditional cam/pincer lesions. Finally, microinstability of the hip from either osseous or capsuloligamentous pathology is increasingly being recognized as a source of hip pain. The present review investigates the pathophysiology and evaluation of alternate causes of hip pain in FAIS that must be evaluated to optimize patient outcomes.

Limited lumbopelvic mobility does not influence short-term outcomes after primary hip arthroscopy: a propensity-matched controlled study

There is a paucity of literature investigating the effect of lumbopelvic mobility on patient-reported outcome scores (PROs) after primary hip arthroscopy. The purpose of this study was (i) to report minimum 1-year PROs in patients with limited lumbopelvic mobility (LM) who underwent primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and (ii) to compare clinical results with a propensity-matched control group of patients with normal lumbopelvic mobility (NM). Data were reviewed for surgeries performed between November 2019 and March 2020. Patients were considered eligible if they received a primary hip arthroscopy for FAIS in the setting of LM (seated to standing change in sacral slope ≤ 10°). LM patients were propensity-matched to a control group of patients with normal lumbopelvic motion (seated to standing change in sacral slope > 10°) for comparison. A total of 17 LM and 34 propensity-matched NM patients were included in the study. LM patients showed significant improvement in all outcome measures and achieved the minimum clinically important difference (MCID) and patient acceptable symptomatic state (PASS) at high rates for modified Harris Hip Score (MCID: 94% and PASS: 82%) and International Hip Outcome Tool-12 (iHOT-12; MCID: 94% and iHOT-12: 76%). When LM patients were compared to a propensity-matched control group of NM patients, they demonstrated similar postoperative PROs and rates of achieving MCID/PASS. LM patients who undergo primary hip arthroscopy may expect favorable short-term PROs at minimum 1-year follow-up. These results were comparable to a control group of NM patients.

Editorial Commentary: Lumbosacral Anatomy and Mechanics Influence Femoroacetabular Impingement Syndrome and Surgical Outcomes: The Hip Bone Is Connected to the Back Bone

The hip joint in general and femoroacetabular impingement (FAI) in particular do not exist in a vacuum. Impingement kinematics are very closely tied to the relationship between spinopelvic motion and posture, and that of the hip joint itself. While the relationship of lumbar degenerative disease, fusion, and sagittal balance to hip arthroplasty has been well studied, there is a paucity of data on the analogous relationship of the stiff spine with hip arthroscopy and FAI. While further studies are critical in advancing our understanding of this relationship in this unique population, surgeons still must consider the relationship of lumbosacral motion and posture, including the anatomic variant of lumbosacral transitional vertebrae, when evaluating and treating patients with FAI.