Preoperative risk factors in hip arthroscopy

Radiological predictors of outcomes in hip arthroscopy for femoroacetabular impingement

Aims

Hip arthroscopy has gained prominence as a primary surgical intervention for symptomatic femoroacetabular impingement (FAI). This study aimed to identify radiological features, and their combinations, that predict the outcome of hip arthroscopy for FAI.

Methods

A prognostic cross-sectional cohort study was conducted involving patients from a single centre who underwent hip arthroscopy between January 2013 and April 2021. Radiological metrics measured on conventional radiographs and magnetic resonance arthrography were systematically assessed. The study analyzed the relationship between these metrics and complication rates, revision rates, and patient-reported outcomes.

Results

Out of 810 identified hip arthroscopies, 359 hips were included in the study. Radiological risk factors associated with unsatisfactory outcomes after cam resection included a dysplastic posterior wall, Tönnis grade 2 or higher, and over-correction of the α angle. The presence of acetabular retroversion and dysplasia were also significant predictors for worse surgical outcomes. Notably, over-correction of both cam and pincer deformities resulted in poorer outcomes than under-correction.

Conclusion

We recommend caution in performing hip arthroscopy in patients who have three positive acetabular retroversion signs. Acetabular dysplasia with a lateral centre-edge angle of less than 20° should not be treated with isolated hip arthroscopy. Acetabular rim-trimming should be avoided in patients with borderline dysplasia, and care should be taken to avoid over-correction of a cam deformity and/or pincer deformity.

Outcomes After Hip Arthroscopy Show No Differences Between Sexes: A Systematic Review

PURPOSE

To assess differences in postoperative outcomes between male and female patients following hip arthroscopy.

METHODS

A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Medline, Embase, Cochrane, and PubMed databases were searched. Key words included "hip," "arthroscopy," "outcome," "gender difference," "sex difference," "gender," and "patient-reported outcome." Studies were included that reported sex-specific analysis of outcomes following primary hip arthroscopy with minimum 2-year follow-up. Methodological Index for Non-Randomized Studies criteria were applied to each study. Data collected included patient-reported outcome measures (PROMs), complications, rates of revision arthroscopy (RA), and conversion to total hip arthroplasty (THA). Forest plots were generated for the most frequently reported PROMs, RA, and THA rates.

RESULTS

In total, 38 studies met the inclusion criteria, with 40,194 (57% female) hips included. The most common indications for hip arthroscopy were femoroacetabular impingement and labral tears. Eighteen studies reported PROMs, with no clear trend towards sex differences. Eleven studies reported on RA rates, with 4 showing a significantly greater rate of RA in female patients. Seventeen studies reported on conversion to THA, with an overall conversion rate of 9.64%. There were no clear sex differences in conversion to THA.

CONCLUSIONS

There was no difference between sexes for postoperative PROM scores. Male patients were less likely to reach the MCID for the HOS-SSS than female patients in the majority of studies, and there were no sex differences for PASS rates. There were no significant differences between sexes in revision arthroscopy rates and conversion to total hip arthroplasty.

LEVEL OF EVIDENCE

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

The HAR-index: a reliable method for evaluating the risk of total hip arthroplasty conversion after hip arthroscopy for femoroacetabular impingement

PURPOSE

Hip arthroscopy is a growing technique in the treatment of femoroacetabular impingement (FAI), but can sometimes lead to unsatisfactory results such as the early conversion to total hip arthroplasty (THA). The purpose of this study is to describe a new tool for assessing the preoperative risk of THA conversion after hip arthroscopy in patients with FAI.

METHODS

This study is a retrospective analysis of a prospective cohort of 584 patients with FAI who underwent hip arthroscopy at a single centre with a minimum 2 years follow-up. The preoperative variables of these patients were analysed to calculate the risk of each variable for THA. By selecting variables with an area under the receiver operating characteristic (ROC) curve greater than 0.7, a calculator was created to provide a risk index for each patient.

RESULTS

Four variables (age, body mass index, Tönnis score and ALAD) were associated with an increased risk of THA conversion. The optimal cut-off points for each variable were determined, and a risk index was created. The Hip-Arthroplasty-Risk Index (HAR-Index) is a 0-4 points scale obtained from four binary scores of 0 or 1 depending on whether the cut-off point for each variable was reached or not. The increased risk of THA for each HAR-Index value was 1.1%, 6.2%, 17.9%, 55.1% and 79.3% respectively. The HAR-Index showed a very good predictive capacity with an area under the ROC curve of 0.89.

CONCLUSION

The HAR-Index is a simple and practical tool for practitioners to make more informed decisions about performing hip arthroscopy in patients with FAI. With a very good predictive capacity, the HAR-Index can help to reduce the rate of conversion to THA.

LEVEL OF EVIDENCE

Level III.

Associating Outcomes After Hip Arthroscopy With Patient Resilience

Background

Higher patient resilience has been shown to be associated with improved patient-reported outcome measures (PROMs) at 6 months after hip arthroscopy.

Purpose

To examine the relationship between patient resilience and PROMs at minimum 2 years after hip arthroscopy.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Included were 89 patients (mean age, 36.9 years; mean follow-up, 4.6 years). Patient demographics, surgical details, and preoperative International Hip Outcome Tool-12 (iHOT-12) and visual analog scale (VAS) pain scores were collected retrospectively. Postoperative variables were collected via a survey and included the Brief Resilience Scale (BRS), Patient Activation Measure-13 (PAM-13), Pain Self-efficacy Questionnaire-2 (PSEQ-2), VAS satisfaction, and postoperative iHOT-12, and VAS pain scores. Based on the number of standard deviations from the mean BRS score, patients were stratified as having low resilience (LR; n = 18), normal resilience (NR; n = 48), and high resilience (HR; n = 23). Differences in PROMs were compared between the groups, and a multivariate regression analysis was performed to assess the relationship between pre- to postoperative change (Δ) in PROMs and patient resilience.

Results

There were significantly more smokers in the LR group compared with the NR and HR groups (P = .033). Compared with the NR and HR groups, patients in the LR group had significantly more labral repairs (P = .006), significantly worse postoperative iHOT-12, VAS pain, VAS satisfaction, PAM-13, and PSEQ-2 scores (P < .001 for all), and significantly lower ΔVAS pain and ΔiHOT-12 scores (P = .01 and .032, respectively). Regression analysis showed significant associations between ΔVAS pain and NR (β = -22.50 [95% CI, -38.81 to -6.19]; P = .008) as well as HR (β = -28.31 [95% CI, -46.96 to -9.67; P = .004) and between ΔiHOT-12 and NR (β = 18.94 [95% CI, 6.33 to 31.55]; P = .004) as well as HR (β = 20.63 [95% CI, 6.21 to 35.05]; P = .006). Male sex was a significant predictor of ΔiHOT-12 (β = -15.05 [95% CI, -25.42 to -4.69]; P = .006).

Conclusion

The study results indicate that lower postoperative resilience scores were associated with significantly worse PROM scores, including pain and satisfaction, at 2 years after hip arthroscopy.

Arthroscopy Confers Excellent Clinical Outcomes in Femoroacetabular Impingement Syndrome (FAIS) Patients Aged 50 Years and Above

OBJECTIVE

Hip preservation surgery has expanded to include treatment of hip pathology in elderly patients. Most data on efficacy of arthroscopy treatment in patients with femoroacetabular impingement syndrome (FAIS) has been generated from Western populations, while studies in the older Asian FAIS population are lacking. Here, we report efficacy of hip arthroscopy for treatment of Asian patients aged 50 years and above.

METHODS

We retrospectively reviewed data from 775 hips that were treated arthroscopically for FAIS between 2016 and 2019. Patients with a history of hip surgery, contralateral surgery during the follow-up period, lateral center-edge angle (LCEA) <25°, Tӧnnis grade ≥2, and incomplete records were excluded. Patient-reported outcomes (PROs), such as modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), International Hip Outcome Tool 12-component form (iHOT-12), and Visual Analog Scale (VAS) were compared pre- and post-operation. We also recorded radiographic measures, intraoperative findings, procedures, complications, and subsequent surgical revisions. Finally, we correlated demographics with PRO improvement among the study group.

RESULTS

A total of 57 hips met the inclusion and exclusion requirements and were therefore included in the final analysis. After the follow-up period (3.3 years), most patients exhibited significantly higher PROs than preoperative values, HOS-ADL (65.0-81.7), iHOT-12 (44.3-69.1), mHHS (58.9-81.7), and VAS (5.8-2.2; all p < 0.001). Shorter symptom duration was significantly correlated with improved HOS-ADL (p = 0.015), and mHHS score (p = 0.022). The overall rate of complications and rate of revisions were 5.3% and 7.0%, respectively, and none of the patients required total hip arthroplasty (THA).

CONCLUSIONS

Arthroscopic surgery confers significant clinical outcomes in most FAIS patients in the Asian population who are aged 50 years and above. These benefits are accompanied by either a low revision rate or conversion to THA, while shorter symptom duration is positively correlated with improved HOS-ADL and mHHS scores.

The traction force of the pulled limb in hip arthroscopic surgery is determined by stiffness coefficient which is significantly related to muscle volume

PURPOSE

To verify the relationship between muscle volume, lateral centre-edge angle (LCEA), alpha angle (AA), body mass index (BMI) and Beighton score with stiffness coefficient (SC). To analyse the difference of traction force at different physical states of hip joint capsule.

METHODS

Thirty-six patients who underwent hip arthroscopy operation were included. The volumes of some related muscles were measured in MRI images by 3D Slicer. We recorded and tested differences in traction force of five joint capsule physical states, including before (State 1) and after joint capsule puncture (State 2), after the establishment of anterolateral and mid-anterior approaches (State 3) and after incision of the joint capsule through these two approaches (States 4, 5). The correlation between muscle volume, BMI, LCEA, AA and SC was verified by Spearman test. Poisson regression was used to explain confounding variables.

RESULTS

The average force at State 1 was 531.8 N. There were significant differences in traction force between these five states (p < 0.001). There was a significant positive correlation between muscle volumes and SC (p < 0.001). BMI had no correlation with SC (n.s.). The preoperative LCEA of the affected side was correlated with SC (p = 0.043). AA and SC were not correlated (n.s.).

CONCLUSION

The physical states of the hip joint capsule affected traction force. Muscle volume rather than BMI is an ideal index to estimate preoperative traction force. LCEA affected traction force, whilst AA and Beighton score did not. Measuring the muscle volume can help estimate the most suitable traction force for the patient.

LEVELS OF EVIDENCE

IV.

Acetabular Cartilage Lesions Predict Inferior Mid-Term Outcomes for Arthroscopic Labral Repair and Treatment of Femoroacetabular Impingement Syndrome

PURPOSE

To analyze the effect of acetabular chondrosis at a minimum of 2 years following hip arthroscopy in patients undergoing labral repair and treatment of femoroacetabular impingement.

METHODS

From 2014 to 2017, patients undergoing arthroscopic labral repair were prospectively enrolled in a multicenter hip arthroscopy registry. The registry was retrospectively queried for primary labral repair patients with complete 2-year outcomes and a Tonnis grade of less than 2. Patients were grouped according to severity of articular cartilage damage noted intraoperatively using the Beck classification system: none, low-grade (Grade 1 or 2), or high-grade (Grade 3 or 4) damage. A Kruskal-Wallis test and post hoc Dunn's test with Holm correction compared 2-year postoperative outcome scores of the iHOT-12 scale between groups. The proportion of patients in each cohort who achieved the clinically significant thresholds of the minimum clinically important difference (MCID), patient-acceptable symptom scale, and substantial clinical benefit (SCB) were analyzed. Multivariate logistic regression models identified predictors of achieving clinical thresholds while controlling for demographic variation.

RESULTS

422 patients met inclusion criteria, from which 347 completed 2-year outcomes. All groups experienced improvement in iHOT-12 scores from baseline to follow-up (P < .001). iHOT-12 scores at follow-up were inferior for Low-Grade Damage and High-Grade Damage Groups relative to the No Damage Group (P = .04; P = .03). When accounting for age, body mass index, gender, and preoperative iHOT-12 scores in logistic regression models, the presence of high-grade lesions was a negative predictor for achieving SCB (OR [95% CI], 0.54 [0.29-0.96]) and low-grade lesions a negative predictor for achieving MCID (0.50 [0.27-0.92]. Among patients with high-grade lesions, there was no significant difference in 2-year iHOT-12 scores between those undergoing chondroplasty (n = 50) and those undergoing microfracture (n = 14) (P = .14).

CONCLUSIONS

Acetabular cartilage damage portends inferior patient-reported outcomes 2 years after primary labral repair and treatment of femoroacetabular impingement. The presence of cartilage lesions was a negative predictor of individual achievement of several clinical thresholds.

LEVEL OF EVIDENCE

III, Retrospective comparative cohort.

Hyperlipidemia does not influence clinical outcome in arthroscopic treatment of femoroacetabular impingement syndrome

Background

Cholesterol can trigger degenerative processes in the chondrocytes. The internal layer of the hip labral consists of cartilage-specific type II collagen-positive fibrocartilage. The purpose of this study was to compare outcomes after arthroscopy labral repair in FAIS patients with preoperative hyperlipidemia to a control group with no hyperlipidemia.

Methods

Data were prospectively collected and retrospectively reviewed for FAIS patients who had arthroscopy 2019. Patients with hyperlipidemia were 1:1 propensity-score matched to patients without hyperlipidemia. Patient-reported outcomes (HOS-ADL, iHOT-12, mHHS), VAS scores, radiographic measures, performed procedures, complications, and revision surgery were compared and analyzed for both groups.

Results

A total of 41 patients with hyperlipidemia and 41 patients without hyperlipidemia were found using propensity-score matching. When compared to preoperative levels, both groups demonstrated significant improvements in PROs and VAS scores at the final follow-up. Besides, there were no significant differences in preoperative scores and final outcome scores between the groups. Besides, there were no other differences in revision rate and the rate of meeting the PASS and MCID between the study and the control groups.

Conclusion

It was demonstrated in this study that FAIS patients with hyperlipidemia can expect to experience similar good short-term patient-reported outcomes as compared with patients without hyperlipidemia.

Level of evidence

Case-series study; Level of Evidence: Level III.

Self-Reported Cannabis Use Is Not Associated With Increased Opioid Use or Costs After Hip Arthroscopy

PURPOSE

Our purpose is to determine the difference in cost, opioid use, and complication rates following hip arthroscopy with or without perioperative cannabis use.

METHODS

Data were collected from a large commercial insurance database (PearlDiver) between the years 2010 and 2019. Patients who underwent hip arthroscopy with reported cannabis use were identified using Common Procedural Terminology codes and the appropriate International Classification of Diseases codes. This group was then matched by age, procedure, gender, Charleston Comorbidity Index, Elixhauser Comorbidity Index), obesity, tobacco use, diabetes to a group of similar patients without self-reported cannabis use. Opioid use over the episode of care, evaluated by morphine milligram equivalents (MME), and 30-day cost were compared between groups using unequal variance t-test.

RESULTS

Of queried patients, 360 (.71%) had a diagnosis of preoperative cannabis use, abuse, or dependence within 5 years prior to their hip arthroscopy. A total of 300 patients (172 female, 128 male) were matched into each hip arthroscopy group, with and without cannabis. Of those patients, 171 without cannabis use and 174 with cannabis use had full financial and opioid use data for analysis. Prescription opioid use was not significantly different over the episode of care in patients with reported cannabis use (1,840 ± 2,743 MME) than those without reported cannabis use (2,129 ± 3,383 MME) (P = .3848). Additionally, episode of care reimbursement cost following hip arthroscopy did not differ significantly between patients with cannabis use ($2957 ± $4428) and those without reported cannabis use ($2,651 ± $3,762) (P = .3620).

CONCLUSIONS

Following hip arthroscopy, patients with reported cannabis use do not appear to have significantly different postoperative opioid use or cost of hip arthroscopy episode of care compared with patients without reported cannabis use.

LEVEL OF EVIDENCE

III, cohort study.

Machine Learning Model Identifies Increased Operative Time and Greater BMI as Predictors for Overnight Admission After Outpatient Hip Arthroscopy

Purpose

The purposes of this study were to identify patient characteristics and risk factors for overnight admission following outpatient hip arthroscopy and to develop a machine learning algorithm that can effectively identify patients requiring admission following elective hip arthroscopy.

Methods

A retrospective review of a prospectively collected national surgical outcomes database was performed to identify patients who underwent elective outpatient hip arthroscopy from 2006 to 2018. Patients admitted overnight postoperatively were identified as those with length of stay of 1 or more days. Models were generated using random forest (RF), extreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), elastic net penalized logistic regression, and an additional model was produced as a weighted ensemble of the four final algorithms.

Results

Overall, 1,276 patients were included. The median age was 43 years, and 64.2% (819) were female. Of the included patients, 109 (8.5%) required an overnight stay following elective outpatient hip arthroscopy. The most important factors for inpatient admission were increasing operative time, general anesthesia, age extremes, male gender, greater body mass index (BMI), American Society of Anesthesiologists classification >1, and the following preoperative lab values outside of normal ranges: sodium, platelet count, hematocrit, and leukocyte count. The ensemble model achieved the best performance based on discrimination assessed via internal validation (area under the curve = .71), calibration, and decision curve analysis. The model was integrated into a Web-based open-access application able to provide both personalized predictions and explanations.

Conclusion

A machine learning algorithm developed based on preoperative features identified increasing operative time, age extremes, greater BMI, sodium, hematocrit, platelets, and leukocyte count as the most important variables associated with inpatient admission with fair validity.