Cotyloid Fossa Coverage Percentages May Be Associated With Alpha Angle, Labral Tear, and Clinical Outcomes in Patients With Femoroacetabular Impingement

Background: Within the hip joint, the anatomy of the acetabulum and cotyloid fossa is well established. There is little literature describing the association between the size of the cotyloid fossa relative to the acetabulum and characteristics of patients with femoroacetabular impingement (FAI). Purpose/Hypothesis: The purpose was to calculate the cotyloid fossa coverage percentage in the acetabulum and determine its association with patient characteristics, radiographic parameters, intra-articular findings, and preoperative patient-reported outcomes in patients with FAI. We hypothesized there is an association between the cotyloid fossa coverage percentage of the acetabulum and characteristics of patients with FAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients were included who underwent standard clinical 3-T magnetic resonance imaging of the hip and primary arthroscopic FAI correction surgery during 2015 and 2016. Exclusion criteria were age <18 or >40 years, osteoarthritis, labral reconstruction, previous ipsilateral hip surgery, and hip dysplasia. Measurements of the cotyloid fossa and surrounding lunate cartilage were performed to calculate cotyloid fossa width (CFW) and cotyloid fossa height (CFH) coverage percentages. The relationships between coverage percentages and patient characteristics and intraoperative findings were assessed using independent t tests or Pearson correlations. Results: An overall 146 patients were included. Alpha angle negatively correlated with CFH coverage percentage ( r = −0.19; P = .03) and positively correlated with labral tear size ( r = 0.28; P < .01). CFH coverage percentage was negatively correlated with labral tear size ( r = −0.24; P < .01). Among patients with degenerative tears, CFH was negatively correlated with labral tear size ( r = −0.31; P < .01). However, this association was no longer significant after adjusting for sex (partial r = −0.10; P = .39). Cotyloid fossa coverage was not associated with the condition of the cotyloid fossa synovium (synovitis vs no synovitis). CFW coverage percentage was negatively correlated with the 12-Item Short Form Health Survey (SF-12) physical component summary score ( r = −0.23; P < .01). Conclusion: The CFW and CFH coverage percentages may be associated with alpha angle, labral tear size, and SF-12 physical component summary score in patients with FAI. We may be able to predict the labral condition based on preoperative measurements of CFH and CFW coverage percentages.

Equality in Hip Arthroscopy Outcomes Can Be Achieved Regardless of Patient Socioeconomic Status

Background: Access to quality health care and treatment outcomes can be affected by patients’ socioeconomic status (SES). Purpose: To evaluate the effect of patient SES on patient-reported outcome measures (PROMs) after arthroscopic hip surgery. Study Design: Cohort study; Level of evidence, 3. Methods: Demographic, radiographic, and intraoperative data were prospectively collected and retrospectively reviewed on all patients who underwent hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and labral tear between February 2008 and September 2017 at one institution. Patients were divided into 4 cohorts based on the Social Deprivation Index (SDI) of their zip code. SDI is a composite measure that quantifies the level of disadvantage in certain geographical areas. Patients had a minimum 2-year follow-up for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), International Hip Outcome Tool—12, and visual analog scale (VAS) for both pain and satisfaction. Rates of achieving the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were calculated for the mHHS, NAHS, and VAS pain score. Rates of secondary surgery were also recorded. Results: A total of 680 hips (616 patients) were included. The mean follow-up time for the entire cohort was 30.25 months. Division of the cohort into quartiles based on the SDI national averages yielded 254 hips (37.4%) in group 1, 184 (27.1%) in group 2, 148 (21.8%) in group 3, and 94 (13.8%) in group 4. Group 1 contained the most affluent patients. There were significantly more men in group 4 than in group 2, and the mean body mass index was greater in group 4 than in groups 1 and 2. There were no differences in preoperative radiographic measurements, intraoperative findings, or rates of concomitant procedures performed. All preoperative and postoperative PROMs were similar between the groups, as well as in the rates of achieving the MCID or PASS. No differences in the rate of secondary surgeries were reported. Conclusion: Regardless of SES, patients were able to achieve significant improvements in several PROMs after hip arthroscopy for FAIS and labral tear at the minimum 2-year follow-up. Additionally, patients from all SES groups achieved clinically meaningful improvement at similar rates.

Arthroscopic Repair of a Posterior Midcapsular Rupture Causing Posterior Shoulder Instability

Background: Gross posterior instability is rare and when found likely has an injury or deficiency to the posterior static restraints of shoulder associated with it. Traditionally, injuries to the posterior capsule have been difficult to diagnose and visualize with magnetic resonance imaging preoperatively, and very little literature regarding arthroscopic repair of posterior capsular tears exists currently. Indications: We present a repair of a posterior midcapsular and posterior labral tear in a 26-year-old man with recurrent left posterior shoulder instability using a novel all–arthroscopic technique. Technique Description: We performed a shoulder arthroscopy in a lateral decubitus position with the arm at 45° of abduction using standard posterior viewing and anterior working portals. Diagnostic arthroscopy revealed a large posterior midcapsular rupture approximately 2 cm lateral to the glenoid with an associated posterior labral tear. We created an accessory posterolateral portal with needle localization that was outside the capsular defect yet allowed access to the posterior labrum. Anatomic closure of the capsular tear was achieved arthroscopically with 3 interrupted No. 2 nonabsorbable sutures in a side–to–side fashion. Posterior labral repair and capsular shift were done to further address the instability using 2 knotless all–suture anchors percutaneously placed at the 7 o'clock and 9 o'clock position. We closed the posterior portal with a combination of curved and penetrating suture passers. Incisions were closed with interrupted 4-0 nylon. Postoperatively, the patient was placed in an ultra–sling for 4 weeks before physical therapy. We allowed light strengthening at 8 weeks, full strengthening at 12 weeks, and estimated return to sport at 4 months. Results: At 6 months postoperatively, the patient has regained symmetric motion, full strength, and has no residual pain or instability. Conclusion: Gross posterior instability is a rare and difficult condition to diagnose and manage. If no significant labral injuries are identified, injury to the posterior capsule must be considered and full assessment should be done when visualizing from the anterior portal. Repair of the posterior capsule is necessary and can be achieved all arthroscopically with this technique.

The Influence of Glenoid Retroversion on Posterior Shoulder Instability: A Cadaveric Study (214)

Objectives: Increased glenoid retroversion has been associated with an increased risk of posterior glenohumeral instability. Normal mean glenoid version is between 0-7° of retroversion depending on the population and measurement method. Retroversion can range above 20°, notably in patients with glenoid dysplasia. Increased glenoid retroversion has also been proposed as a risk factor for failure after primary soft tissue repair. Arthroscopic repair is the most common surgical treatment; however, this does not address cases of increased glenoid retroversion. What has not been identified is the degree of glenoid retroversion associated with recurrent instability or failed repair. The goal of our work is to (1) measure how resistance to posterior translation changes as retroversion increases, (2) examine if labral tear results in a greater decrease to resistance at increasing degrees of retroversion, and (3) to determine the degree of retroversion at which labral repair fails to restore the resistance of the intact, neutral version state. Methods: Eight fresh frozen cadaveric shoulder specimens (age 50-64, 4 male) were prepared, maintaining bone and capsulolabral tissue. The scapula and humerus were potted using quick-set polyurethane. CT scans were obtained to establish a scapular 3D coordinate system relative to the potting. Specimens were mounted on a 6 degree of freedom musculoskeletal simulation robotic arm (KUKA KR 6 R700, Augsburg, Germany) and referenced to the coordinate system. The humeral head was centered on the glenoid using a 50N compressive force, and the humerus was translated posterior-inferiorly (30° inferior to the midline) at 1mm/sec in neutral rotation for 10mm. The shoulder was positioned in 30° of abduction and 30° of flexion, based on prior protocol. Custom simVITRO (Cleveland Clinic, Ohio, US) labview-based control software measured peak resistance at 0° of version and then in 5° increments of retroversion until the specimen dislocated, up to 30° of retroversion. Version was adjusted through use of a multiplanar vice. A posterior labral tear was created from the 2 to 6 o’clock position on a left shoulder, and the same testing parameters were performed. Vertical mattress sutures using 4 independent bone tunnels were used to repair the labrum and the same version iterations were tested. Generalized estimating equations were used to compare the peak resistance to translation for each degree of version in the intact, cut and repaired states. The maximum likelihood estimators of the model were adjusted for any model misspecification using classical sandwich estimation. Post hoc pairwise comparisons between conditions were conducted via orthogonal contrasts. The Holm-test was used to calculate adjusted p-values and confidence intervals. Statistical significance was established at the P<0.05 level and all interval estimates were calculated for 95% confidence. Results: The mean peak resistance for the intact labral state decreased significantly for each interval increase in retroversion when the humerus was translated posterior-inferiorly (Figure 1). On average, a 1° increase in retroversion correlated with a 3.5% decrease in resistance to translation. Dislocation with an intact labrum without any posterior force occurred at a mean of 22.7° (range 15-30°) of retroversion. After labral tear, resistance forces to posterior-inferior translation decreased but not significantly from the intact state. However, the percent change of resistance force decreased 41% at 25° of retroversion; this was notably higher than the percent change at 0-15° of retroversion (range 2.7-6.5% decrease) but was not statistically significant (Figure 2). Compared to the intact state at 0° version, there was a 45% and 81% decrease in resistance after labral repair at 20° and 25° of retroversion, respectively (p=0.04 and p=0.004). Conclusions: Glenoid retroversion has a significant effect on resistance to posterior humeral head translation, with each degree increase accounting for 3.5% of resistance to translation. Cutting the labrum at 0-15° of retroversion does not have a significant effect on resistance to posterior inferior humeral translation; however, at 25° of retroversion cutting the labrum results in a 41% decrease in resistance. Similarly, labral repair at 20-25° of retroversion does not recreate peak resistance values of the intact state at 0-5° of retroversion. These findings point to the bony anatomy (retroversion) playing a larger role in preventing posterior instability than the labrum. It also provides evidence that the labrum plays a more significant role in stability at higher degrees of retroversion, and labral repair in patients with >20° of retroversion may be subjected to a relatively greater percentage of force than those at lesser degrees of retroversion.

The correlation between the labrum size and the labral tear in asymptomatic volunteers and symptomatic patients

Background Some studies have proved that labrum size is associated with symptoms in patients with hip labral tear. The correlation between the labrum size and the labral tear in asymptomatic volunteers and symptomatic patients is still uncertain. Methods The volunteers with no history of pain, injury, or surgery were recruited from the community. Patients who were diagnosed with labral tear and underwent hip arthroscopic surgery in this period in our hospital were also included. The length and height of the acetabular hip labrum were measured at three separate anatomic sites through magnetic resonance imaging (MRI) along the acetabular rim: lateral, anterior, and anteroinferior. Results A total of 70 volunteers (125 hips) and 70 patients (70 hips) were included in this study. Sixty-six (52.8%) hips had labral tears in all 125 hips of volunteers. The lateral labral length of volunteers with labral tears was significantly larger than those without labral tears (P < .05). In 14 volunteers with unilateral labral tears, length of lateral, anterior, and anteroinferior labrum in the side with tear were significantly larger than normal on the other side. The anterior labral height of volunteers was significantly larger than that of patients (P < .05). Conclusions In conclusion, asymptomatic volunteers with larger length of lateral, anterior, and anteroinferior labrum are more prone to present with labral tears. Symptomatic patients with labral tears exhibited thinner anterior labrum. Further studies are warranted to explore the mechanisms of labral tears in asymptomatic people and validate the use of labral size as a guide to differential diagnosis and treatment.

Multicenter Outcomes After Hip Arthroscopy: Comparative Analysis of Patients Undergoing Concomitant Labral Repair and Ligamentum Teres Debridement Versus Isolated Labral Repair

Background: Increased attention has been directed toward the ligamentum teres (LT) and its association with acetabular coverage, labral pathology, and hip microinstability; however, few studies have evaluated whether LT pathology influences the rate of clinically significant outcome improvement after hip arthroscopy. Purpose: To determine if patients with femoroacetabular impingement syndrome (FAIS) undergoing labral repair and concomitant LT debridement achieve outcomes similar to patients without LT pathology undergoing labral repair. Study Design: Cohort study; Level of evidence, 3. Methods: We conducted a retrospective review of a prospectively maintained multicenter database for hip arthroscopy. Included were patients with FAIS who underwent primary labral repair and who had preoperative and minimum 2-year postoperative outcome scores. Patients diagnosed with concomitant partial LT tear were identified and matched 1:3 according to age, sex, and body mass index (BMI) to patients without LT pathology. The following clinical outcomes were compared between groups: modified Harris Hip Score, Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sport Subscale, International Hip Outcome Tool, and visual analog scale for pain and satisfaction. Achievement of the minimal clinically important difference and patient acceptable symptomatic state was also compared between groups. Results: This study included 124 patients with FAIS with labral tear and concomitant partial LT tear and 372 patients with labral tear and no LT pathology. The age, BMI, and sex of the matched cohort were 38.0 ± 12.0 years (mean ± SD), 24.3 ± 3.6 kg/m2, and 62.0% female, respectively. No significant difference in age, BMI, sex, workers’ compensation status, or duration of pain was observed at baseline. Analysis of radiographic parameters indicated that patients who underwent isolated labral repair had a lower preoperative Tönnis angle (4.8° ± 4.4° vs 6.3° ± 5.4°; P = .006). There were no significant differences between groups on any pre- or postoperative outcome measure, and there were no significant differences in the proportion of patients who achieved the minimal clinically important difference or patient acceptable symptomatic state on any outcome measure. Conclusion: Patients with labral tear and concomitant partial LT tear experienced similar preoperative scores and achieved similar outcomes as patients with isolated labral tears after hip arthroscopy.