Background: The clinical and radiographic features of iatrogenic hip instability following hip arthroscopy have been described. However, the prevalence of presenting symptoms and associated imaging findings in patients with hip instability has not been reported. Purpose: To detail the prevalence of clinical and magnetic resonance arthrogram (MRA) findings in a cohort of patients with isolated hip instability and to determine midterm patient-reported outcomes in this patient population. Study Design: Case series; Level of evidence, 4. Methods: We retrospectively reviewed patients from 2014 to 2016 who underwent an isolated capsular repair in the revision hip arthroscopy setting. Patients were excluded if they underwent any concomitant procedures, such as labral repair, reconstruction, femoral osteoplasty, or any other related procedure. Several clinical data points were reviewed, including painful activities, mechanical symptoms, subjective instability, Beighton scores, axial distraction testing (pain, toggle, and apprehension), and distractibility under anesthesia. Patient-reported outcomes—including modified Harris Hip Score, Hip Outcome Score–Sports Subscale, Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function Computer Adaptive Test, and a return patient hip questionnaire—were collected pre- and postoperatively. Pre-revision radiographs were obtained, and lateral center-edge angle and alpha angle were measured on anteroposterior and frog-leg lateral views, respectively. Pre-revision MRAs were reviewed and evaluated for capsular changes. Capsular changes were defined as follows: 0, normal; 1, capsular redundancy; 2, focal capsular rent; and 3, gross extravasation of fluid from the capsule. Results: A total of 31 patients met inclusion criteria (5 male, 26 female; 14 right and 17 left hips). The mean age of patients was 36 years (range, 20-58 years). Overall, 27 (87%) reported hip pain with activities of daily living, and 31 (100%) experienced pain with sports or exercise. In addition, 24 (77%) had at least 1 positive finding on axial distraction testing. All patients had evidence of capsular changes on review of pre-revision MRAs. Out of 31 patients, 23 (74%) were available for follow-up at a minimum of 3.3 years and a mean ± SD of 4.6 ± 0.8 years. On average, modified Harris Hip Score improved by 20.3, Hip Outcome Score–Sports Subscale by 25.1, and PROMIS Physical Function Computer Adaptive Test by 6.4. Additionally, 20 (87%) patients reported improved or much improved physical ability, and 18 (78%) reported improved or much improved pain. Conclusion: The current study suggests that patients with hip instability demonstrate high rates of pain with activities of daily living and exercise, positive findings on axial distraction testing, and evidence of capsular changes on magnetic resonance imaging. Furthermore, these patients improve with revision surgery for capsular repair at midterm follow-up.

No abstract

Background:Cadaveric models demonstrate that failure of hip capsular repair is dependent on the robustness of the repair construct. In vivo data on capsular repair construct efficacy are limited. We investigated the effect of a figure-of-8 capsular repair on hip distraction resistance relative to native and post-capsulotomy states. We hypothesized that an unrepaired capsulotomy would demonstrate increased axial distraction compared with the native state and that capsular repair would restore distraction resistance to native levels.Methods:Patients undergoing primary hip arthroscopy by a single surgeon were prospectively enrolled between March 2020 and June 2020. Prior to any instrumentation, fluoroscopic images of the operative hip were obtained at 12.5-lbs (5.7-kg) traction intervals, up to 100 lbs (45.4 kg). Anterolateral, modified anterior, and distal anterolateral portals were established. Following interportal capsulotomy, labral repair, and osteochondroplasty, fluoroscopic images were reobtained at each traction interval. Capsular repair was performed with use of a figure-of-8 suture configuration. Traction was reapplied and fluoroscopic images were again obtained. Joint distraction distance was measured at each traction interval for all 3 capsular states. Anteroposterior pelvic radiographs were utilized to scale fluoroscopic images to obtain joint space measurements in millimeters.Results:A total of 31 hips in 31 patients were included. Capsulotomy resulted in significant increases in distraction distance from 25 (11.3 kg) to 100 lbs of traction compared with both native and capsular repair states (all comparisons, p ≤ 0.017). Capsular repair yielded a significantly greater distraction distance compared with the native state at 37.5 lbs (17.0 kg; 5.49 versus 4.98 mm, respectively; p = 0.012) and 50 lbs (22.7 kg; 6.08 versus 5.35 mm; p < 0.001). The mean difference in distraction distance between native and capsular repair states from 25 to 100 lbs of traction was 0.01 mm.Conclusions:This in vivo model demonstrates that an unrepaired interportal capsulotomy significantly increases axial distraction distance compared with the native, intact hip capsule. Performing a complete capsular closure reconstitutes resistance to axial distraction intraoperatively. Future research should evaluate the in vivo effects and associated clinical outcomes of other published capsular repair techniques and assess the durability of capsular repairs over time.

No abstract

To evaluate short-to mid-term outcomes after arthroscopic operative fixation of tibial spine fractures in pediatric patients, to determine the incidence of further ipsilateral and contralateral knee injuries, and to describe associated meniscal pathology and intraoperative findings at the time of tibial spine repair. Methods: All patients under age 18 with a tibial spine fracture treated arthroscopically at 1 institution by 2 surgeons from 2008 through 2019 were identified by Current Procedural Terminology codes. Patients at least 1 year from their date of surgery were contacted to complete a questionnaire, which included the International Knee Documentation Committee (IKDC) form. Questions pertained to knee function, pain, and further injury or surgery on either knee. Patient charts, preoperative imaging, and operative reports were reviewed to determine demographic information, tibial spine fracture type, concomitant injuries, and intraoperative details. Results: Sixty-six of 97 eligible patients (68%) completed questionnaires. Average age at initial surgery was 10.7 years (range, 4-17). Mean follow-up was 5.8 years (range, 1.0-11.9). Average IKDC score at follow-up was 91.4 (range, 62.1-100). Patients reported their knee as 92% of "normal" (range, 40-100). Thirty-five (53%) currently participate in sport; 6 (9%) remain limited because of instability and residual pain. Regarding pain on a visual analog scale, 94%, 95%, and 83% of patients reported less than a 3 at rest, with daily activity, and with sport, respectively. Seven patients (11%) had subsequent ACL rupture. Six patients (9%) underwent ACL reconstruction 3.1 years (range, 0.9-7) after initial repair. Fourteen patients (21%) required at least 1 additional procedure. Regarding the contralateral knee, there were no ACL or tibial spine injuries. Sixty-one (92%) patients were both satisfied and would definitely undergo the procedure again. Conclusions: Although many pediatric patients demonstrate excellent results after tibial spine repair at mean 5.8 years follow-up, 10.6% sustained an ipsilateral ACL rupture, and 21% required an additional procedure. No patient had a contralateral tibial spine or ACL injury. This is helpful when counseling patients regarding injury risk when returning to activity after tibial spine repair. Level of Evidence: Level IV, therapeutic case series.