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.

Repair of gluteus medius tears with bioinductive collagen patch augmentation: initial evaluation of safety and imaging.

The purpose of this study was to perform an initial, prospective evaluation of imaging findings and outcomes after open surgical repair of gluteus medius tendon tears with bioinductive collagen patch augmentation. A prospective study was performed of patients with clinical and magnetic resonance imaging (MRI) evidence of symptomatic gluteus medius tears who underwent open, double-row suture anchor repair with bioinductive bovine collagen patch augmentation. Preoperative and 6-month postoperative MRIs were reviewed by a fellowship-trained musculoskeletal radiologist, and outcome scores were recorded preoperatively and 6 months postoperatively [Hip Outcome Score (HOS) Sport; HOS Activities of Daily Living (HOS ADL); Modified Harris Hip Score (mHHS) and International Hip Outcomes Tool (iHOT-33)]. Nine patients, four high-grade tears (≥50% tendon thickness) and five low-grade tears (<50% thickness) underwent surgical repair. At 6 months, 7/9 (77.8%) of tendons were qualitatively classified as completely healed on MRI, with no complications. Mean tendon thickness increased significantly: mediolateral dimension by 5.8 mm (P < 0.001), anteroposterior dimension by 4.1 mm (P = 0.02) and cross-sectional area (CSA) by 48.4 mm2 (P = 0.001). Gluteus medius and minimus CSA did not change significantly (P > 0.05). Patients demonstrated improvements in mean scores for HOS ADL, mHHS and iHOT that met defined minimum clinically important differences (P < 0.05). Open surgical repair of gluteus medius tendon tears with bioinductive collagen patch augmentation is safe and associated with increased tendon thickness on postoperative MRI. Early outcome scores are encouraging and should be evaluated after patients have completed postoperative rehabilitation to measure the whole effect of treatment.

The predictive value of self-reported allergies for reoperation after index hip arthroscopy.

The purpose of this study is to compare the rate of reoperation after index hip arthroscopy for symptomatic femoroacetabular impingement in patients with, and without, at least one self-reported allergy. Data were collected prospectively in 1468 patients whose records were retrospectively reviewed. After the application of inclusion and exclusion criteria, two cohorts were formed: (i) a study cohort (n = 261) composed of patients with a self-reported allergy and (ii) a control cohort. (n = 666). The allergy cohort had a significantly larger [P < 0.001] reoperation rate (24.1% [63/261]) compared to the control cohort (9.6% [64/66]). Univariate analysis (UVA) and multivariate analysis (MVA) were then performed to better understand the implications of allergy status on the arthroscopic outcome. On UVA the presence of an allergy increased the odds of reoperation after index hip arthroscopy by 2.99 [OR (95% CI): 2.99 (2.04, 4.39); P < 0.001] and for each additional allergy a patient reported, their odds of subsequent surgery increased by 1.27 per allergy [OR (95% CI): 1.27 (1.15, 1.39); P < 0.001]. However, on the MVA, allergy status was not an independent risk factor for reoperation. These findings suggest that allergy status is associated with a higher reoperation rate, however, allergy status alone cannot prognosticate the risk of subsequent surgery. Therefore, allergy status and its association with future surgery after hip arthroscopy should be considered in the context of multiple patient-specific factors that influence the surgical outcome. An understanding of this association enables patient-centered care and will strengthen the physician-patient relationship.

Extreme Hinge Axis Positions Are Necessary to Achieve Posterior Tibial Slope Reduction With Small Coronal-Plane Corrections in Medial Opening Wedge High Tibial Osteotomy.

Background: Both coronal- and sagittal-plane knee malalignment can increase the risk of ligamentous injuries and the progression of degenerative joint disease. High tibial osteotomy can achieve multiplanar correction, but determining the precise hinge axis position for osteotomy is technically challenging. Purpose: To create computed tomography (CT)-based patient-specific models to identify the ideal hinge axis position angle and the amount of maximum opening in medial opening wedge high tibial osteotomy (MOWHTO) required to achieve the desired multiplanar correction. Study Design: Descriptive laboratory study. Methods: A total of 10 patients with lower extremity CT scans were included. Baseline measurements including the mechanical tibiofemoral angle (mTFA) and the posterior tibial slope (PTS) were calculated. Virtual osteotomy was performed to achieve (1) a specified degree of PTS correction and (2) a planned degree of mTFA correction. The mean hinge axis position angle for MOWHTO to maintain an anatomic PTS (no slope correction) was 102.6° ± 8.3° relative to the posterior condylar axis (PCA). Using this as the baseline correction, the resultant hinge axis position and maximum opening were then calculated for each subsequent osteotomy procedure. Results: For 5.0° of mTFA correction, the hinge axis position was decreased by 6.8°, and the maximum opening was increased by 0.49 mm for every 1° of PTS correction. For 10.0° of mTFA correction, the hinge axis position was decreased by 5.2°, and the maximum opening was increased by 0.37 mm for every 1° of PTS correction. There was a significant difference in the trend-line slopes for hinge axis position versus PTS correction (P = .013) and a significant difference in the trend-line intercepts for maximum opening versus PTS correction (P < .0001). Conclusion: The mean hinge axis position for slope-neutral osteotomy was 102.6° ± 8.3° relative to the PCA. For smaller corrections in the coronal plane, more extreme hinge axis positions were necessary to achieve higher magnitudes of PTS reduction. Clinical Relevance: Extreme hinge axis positions are technically challenging and can lead to unstable osteotomy. Patient-specific instrumentation may allow for precise correction to be more readily achieved.

Failure to Achieve Threshold Scores on Patient-Reported Outcome Measures Within 1 Year Has a Predictive Risk of Subsequent Hip Surgery Within 5 Years of Primary Hip Arthroscopy: A Case-Control Study.

BACKGROUND: Research has identified factors that influence achievement rates of threshold scores on patient-reported outcome measures (PROMs) after hip arthroscopy. However, little data exist on whether failure to achieve a threshold score (minimal clinically important difference [MCID] or substantial clinical benefit [SCB]) in the short term after hip arthroscopy predicts the risk of future hip surgery. PURPOSE/HYPOTHESIS: The purpose of this study was to determine if failure to achieve the MCID or SCB on PROMs within 1 year of hip arthroscopy can be considered a risk factor for repeat surgery within 5 years of primary hip arthroscopy. It was hypothesized that failure to achieve threshold scores would increase the risk of subsequent hip surgery. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A retrospective review of prospectively collected data was completed. Four PROMs were collected preoperatively and within 1 year of hip arthroscopy: modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports, and the 33-Item International Hip Outcome Tool. RESULTS: Two cohorts were formed: (1) a study cohort (n = 88) composed of patients who underwent repeat hip surgery within 5 years of hip arthroscopy and (2) a control cohort (n = 288) composed of patients who did not require repeat hip surgery. The study cohort had significantly (P < .001) lower scores on all postoperative PROMs, and a significantly (P < .001) smaller percentage of the study cohort met the MCID and SCB. Multivariable regression analysis demonstrated that not achieving the MCID or SCB on each of the PROMs is an independent risk factor for repeat hip surgery. For every PROM in which a patient failed to achieve the MCID, the odds of subsequent surgery increased by 1.68 (95% CI, 1.42-1.98; P < .001). For every PROM in which a patient failed to achieve the SCB, the odds of subsequent surgery increased by 1.63 (95% CI, 1.35-1.97; P < .001). CONCLUSION: Failure to meet threshold scores on PROMs after hip arthroscopy was an independent risk factor for subsequent hip surgery. This study establishes a novel utility of PROMs and confirms the importance of these metrics in the orthopaedic literature.

The Ideal Hinge Axis Position to Reduce Tibial Slope in Opening-Wedge High Tibial Osteotomy Includes Proximalization-Extension and Internal Rotation.

PURPOSE: To evaluate the effect of the hinge axis position on the posterior tibial slope (PTS) in medial opening-wedge high tibial osteotomy. METHODS: This study included adults with medial-compartment osteoarthritis who had computed tomography (CT) scans available that were amenable to Bodycad Osteotomy software analysis. Virtual osteotomies modeling a 10-mm medial opening-wedge gap were performed. The hinge axis was rotated internally and externally and was proximalized-extended and distalized-flexed with respect to the anterior tibial cortex for 5°, 10°, 15°, and 20°. Each resultant PTS was recorded and compared with the results obtained from the true lateral hinge position and with the preoperative PTS. RESULTS: Computed tomography scans from 10 patients were used. Strong linear correlations were found with each hinge axis position change and the resultant PTS. The trend-line differences were statistically significant by single-factor analysis of variance (P < .001). The PTS decreased for an anterolateral hinge, whereas it increased for a posterolateral hinge. Linear regression analysis showed that rotating the hinge axis by 9.0° externally or angulating the hinge axis by 21.8° of distalization-flexion would result in increasing the tibial slope by 1° whereas rotating the hinge axis by 8.7° internally or angulating the hinge axis by 21.6° of proximalization-extension would decrease the tibial slope by 1°. CONCLUSIONS: Distalization-flexion and external rotation of the hinge axis position led to stepwise increases in the PTS, whereas proximalization-extension and internal rotation led to decreases in the PTS. CLINICAL RELEVANCE: Our findings suggest that when performing medial opening-wedge high tibial osteotomy and aiming to decrease the PTS, the surgeon should aim to achieve maximal internal rotation (producing an anterolateral hinge), as well as proximalization-extension, of the hinge axis. This study quantifies and provides a model for the effect of the hinge axis position for a predetermined angular correction on the PTS.

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

BACKGROUND: While the association between spinal disease and hip arthroplasty outcomes has been well studied, there is less known about the effect of spinal pathology in hip arthroscopy (HA) outcomes. Lumbosacral transitional vertebrae (LSTV) are anatomic variations where caudal vertebrae articulate or fuse with the sacrum or ilium. HYPOTHESIS: LSTV can lead to inferior outcomes after HA for treatment of femoroacetabular impingement. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We retrospectively reviewed the prospectively collected Hip Arthroscopy Database at our institution for patients with LSTV who underwent HA between 2010 and 2017. A total of 62 patients with LSTV were identified and then matched to controls. Patient-reported outcome measures (PROMs) were collected, including the modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports, and the 33-item International Hip Outcome Tool. They were collected at 4 time points: preoperatively and 5 to 11 months, 12 to 23 months, and 24 to 35 months postoperatively. Longitudinal analysis of the PROMs was done using generalized estimating equation modeling. Additionally, alpha angles were measured from preoperative radiographic data. RESULTS: Preoperatively, there was no significant difference between patients with and without LSTV on 3 of the 4 PROMs; however, patients with LSTV did have significantly lower preoperative scores than controls for the Hip Outcome Score-Activities of Daily Living (P = .029). Patients with LSTV reported significantly lower scores on all 4 PROMs at each postoperative time point. Radiographic data showed no significant difference in alpha angles across cohorts. When LSTV were compared by Castellvi type, types 3 and 4 tended to have lower scores than types 1 and 2; however, these comparisons were not significant. CONCLUSION: The data support our hypothesis that HA has less benefit in patients with LSTV as compared with patients without LSTV. In patients with LSTV, careful evaluation of the anomaly is recommended to help guide surgical counseling and manage expectations.

Self-reported allergies correlate with a worse patient-reported outcome after hip arthroscopy: a matched control study.

Patient-reported outcome measures (PROMs) in patients with and without at least one self-reported allergy undergoing hip arthroscopy were compared. Data on 1434 cases were retrospectively reviewed, and 267 patients were identified with at least one self-reported allergy and randomly matched to a control group on a 1:2 ratio. Four PROMs [Modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports (HOS-Sport) and 33-item International Hip Outcome Tool (iHOT-33)] were collected preoperatively, and at 5-11, 12-23 and 24-35 months postoperatively. Significant PROM differences were found 5-11 months postoperative on mHHS (P < 0.001), HOS-ADL (P = 0.002), HOS-Sport (P < 0.001) and iHOT-33 (P < 0.001). At 12-23 months postoperative, the allergy cohort had significantly worse scores on mHHS (P = 0.002), HOS-ADL (P = 0.001), HOS-Sport (P < 0.001) and iHOT-33 (P < 0.001). They also had significantly worse measures 24-35 months postoperative on mHHS (P = 0.019), HOS-Sport (P = 0.006) and iHOT-33 (P < 0.001). Multivariable logistic regression showed that each additional allergy reported significantly increased the risk of failing to meet the minimal clinically important difference 5-11 months after surgery on mHHS by 1.15 [OR (95% CI): 1.15 (1.03, 1.30), P = 0.014], on HOS-ADL by 1.16 [OR (95% CI): 1.16 (1.02, 1.31), P = 0.021] and on iHOT-33 by 1.20 [OR (95% CI): 1.20 (1.07, 1.36), P = 0.002]. Results suggest self-reported allergies increase the likelihood of a patient-perceived worse outcome after hip arthroscopy. An understanding of this association by the physician is essential during presurgical planning and in the management of postoperative care.

Editorial Commentary: Safe Insertion of Acetabular Labral Anchors-Preventing and Detecting Subchondral and Far Cortical Perforations.

Hip arthroscopy is a rapidly expanding and extremely technically challenging field used to manage mechanical hip derangement. Subchondral and far cortical perforations during anchor insertion are known complications of labral fixation, and evidence-based guidelines on anchor insertion are lacking. The use of curved drill guides 1 to 1.5 mm off the acetabular rim through a distal anterolateral accessory portal gives the lowest chance of both subchondral and far cortical perforations. We always use a flexible wire for portals anterior to the 1-o'clock position; this allows the detection of far cortical perforation prior to anchor insertion. We have found that the routine use of these guidelines minimizes the risk of inserting anchors into the subchondral area or through the far cortex.

A history of spine surgery predicts a poor outcome after hip arthroscopy.

This study compared patient reported outcomes scores (PROMs) between patients undergoing hip arthroscopy who have and have not had previous lumbar spine surgery. We aimed to determine if prior spine surgery impacts the outcome of hip arthroscopy. Data were prospectively collected and retrospectively reviewed in patients who underwent hip arthroscopy between 2010 and 2017. Twenty cases were identified for analysis and matched to a control group. Four PROMs were collected pre-operatively and between 6 months and 2 years post-operatively (mean 16.2 months): Modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports (HOS-Sports) and the 33-item International Hip Outcome Tool (iHOT-33). Patients with previous spine surgery reported significantly worse (P-value <0.001) post-operative scores on all PROMs and smaller net changes on all PROMs with the difference on the mHHS (P-value 0.007), HOS-Sport (P-value 0.009) and iHOT-33 (P-value 0.007) being significant. Subsequent analyses revealed that the type of spine surgery matters. Patients with a spine fusion reported worse post-operative scores on all PROMs compared with patients with a spine decompression surgery with the difference on the mHHS (P-value 0.001), HOS-ADL (P-value 0.011) and HOS-Sport (P-value 0.035) being significant. Overall, patients with prior decompression surgery experienced considerable improvements from hip arthroscopy whereas patients with a prior spine fusion reported poor post-operative outcomes. Given these results, it is vital that hip preservation surgeons understand the impact of the lumbar spine on the outcome of hip arthroscopy.

In vitro measurement of the permeability of endovascular coils deployed in cerebral aneurysms.

BACKGROUND AND PURPOSE: Aneurysm recurrence is the primary limitation of endovascular coiling treatment for cerebral aneurysms. Coiling is currently quantified by a volumetric porosity measure called packing density (pd). Blood flow through a coil mass depends on the permeability of the coil mass, and not just its pd. The permeability of coil masses has not yet been quantified. Here we measure coil permeability with a traditional falling-head permeameter modified to incorporate idealized aneurysms. METHODS: Silicone replicas of idealized aneurysms were manufactured with three different aneurysm diameters (4, 5, and 8 mm). Four different coil types (Codman Trufill Orbit, Covidien Axium, Microvention Microplex 10, and Penumbra 400) were deployed into the aneurysms with a target pd of 35%. Coiled replicas were installed on a falling-head permeameter setup and the time taken for a column of fluid above the aneurysm to drop a certain height was recorded. Permeability of the samples was calculated based on a simple modification of the traditional permeameter equation to incorporate a spherical aneurysm. RESULTS: The targeted 35% pd was achieved for all samples (35%±1%, P=0.91). Coil permeabilities were significantly different from each other (P<0.001) at constant pd. Microplex 10 coils had the lowest permeability of all coil types. Data suggest a trend of increasing permeability with thicker coil wire diameter (not statistically significant). CONCLUSIONS: A simple in vitro setup was developed to measure the permeabilities of coil masses based on traditional permeametry. Coil permeability should be considered when evaluating the hemodynamic efficacy of coiling instead of just packing density. Coils made of thicker wires may be more permeable, and thus less effective, than coils made from thinner wires. Whether aneurysm recurrence is affected by coil wire diameter or permeability needs to be confirmed with clinical trials.