The Otto Aufranc Award: Does Hip Arthroscopy at the Time of Periacetabular Osteotomy Improve the Clinical Outcome for the Treatment of Hip Dysplasia? A Multi-Center Randomized Clinical Trial.

BACKGROUND: A periacetabular osteotomy (PAO) is often sufficient to treat the symptoms and improve quality of life for symptomatic hip dysplasia. However, acetabular cartilage and labral pathologies are very commonly present, and there is a lack of evidence examining the benefits of adjunct arthroscopy to treat these. The goal of this study was to compare the clinical outcome of patients undergoing PAO with and without arthroscopy, with the primary endpoint being the International Hip Outcome Tool-33 (iHOT-33) at one year. METHODS: In a multi-center study, two hundred and three patients who had symptomatic hip dysplasia were randomized: 97 patients undergoing an isolated PAO (mean age 27 years (range, 16 to 44); mean Body Mass Index (BMI) of 25.1 (range, 18.3 to 37.2); 86% women) and 91 patients undergoing PAO who had an arthroscopy [mean age 27 years (range, 16 to 49); mean BMI of 25.1 (17.5 to 25.1); 90% women]. RESULTS: At a mean follow up of 2.3 years (range, 1 to 5), all patients exhibited significant improvements in their functional score, with no significant differences between PAO plus arthroscopy versus PAO alone at 12 months post-surgery on all scores: pre-operative iHot-33 score of 31.2 (SD [standard deviation] 16.0) versus 36.4 (SD 15.9), and 12 months post-operative score of 72.4 (SD 23.4) versus 73.7 (SD 22.6)]. The pre-operative Hip disability and Osteoarthritis Outcome (HOOS)-pain score was 60.3 (SD 19.6) versus 66.1 (SD 20.0)] and 12 months post-operative [88.2 (SD 15.8) versus 88.4 (SD 18.3)]. The mean pre-operative physical health Patient-Reported Outcomes Measurement Information System (PROMIS) score was 42.5 (SD 8.0) versus 44.2 (SD 8.8) and 12 months post-operative [48.7 (SD 8.5) versus 52.0 (SD 10.6)]. There were four patients with PAO without arthroscopy who required an arthroscopy later to resolve persistent symptoms, and one patient from the PAO plus arthroscopy group required an additional arthroscopy. CONCLUSION: This Randomized Controlled Trial (RCT) has failed to show any significant clinical benefit in performing hip arthroscopy at the time of the PAO at one-year follow-up. Longer follow-up will be required to determine if hip arthroscopy provides added value to a PAO for symptomatic hip dysplasia.

Risk Factors for Suboptimal Outcome of FAI Surgery in the Adolescent Patient.

BACKGROUND: Surgical treatment for adolescent patients with femoroacetabular impingement (FAI) is increasing. The purpose of this study was to determine the clinical outcomes of FAI surgery in a multicenter cohort of adolescent patients and to identify predictors of suboptimal outcomes. METHODS: One hundred twenty-six adolescent hips (114 patients < 18 years of age) undergoing surgery for symptomatic FAI were studied from a larger multicenter cohort. The group included 74 (58.7%) female and 52 male hips (41.3%) with a mean age of 16.1 (range 11.3 to 17.8). Clinical outcomes included the modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (5 domains), and University of California Los Angeles activity score. Failure was defined as revision surgery or clinical failure (inability to reach minimally clinical important differences or patient acceptable symptoms state for the mHHS). Statistical analysis was used to identify factors significantly associated with failure. RESULTS: There was clinically important improvement in all patient-reported outcomes for the overall group, but an 18.3% failure rate. This included a revision rate of 8.7%. Females were significantly more likely than males to be classified as a failure (25.7 vs. 7.7%, P =0.01), in part because of lower preoperative mHHS (59.1 vs. 67.0, P < 0.001). Mild cam deformity (alpha angle <55 degrees) was present in 42.5% of female hips compared with 17.3% male hips. Higher alpha angles were inversely correlated with failure. Alpha angles >63 have a failure rate of 8.3%, between 55 and 63 degrees, 12.0% failure rate, and <55 degrees (mild cam) failure rate of 37.5%. Patients who participated in athletics had a 10.3% failure rate compared with nonathletes at 25.0% ( P =0.03, RR (relative risk) 2.4). CONCLUSIONS: Adolescent patients undergoing surgical treatment for FAI generally demonstrate significant improvement. However, female sex, mild cam deformities, and lack of sports participation are independently associated with higher failure rates. These factors should be considered in surgical decision-making and during patient counseling. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

The Impact of Age on Clinical Outcomes of Acetabular Microfracture During FAI Surgery.

BACKGROUND: Full-thickness acetabular cartilage lesions are common findings during primary surgical treatment of femoroacetabular impingement (FAI). PURPOSE: To evaluate clinical outcomes after acetabular microfracture performed during FAI surgery in a prospective, multicenter cohort. STUDY DESIGN: Cohort Study; Level of evidence, 3. METHODS: Patients with FAI who had failed nonoperative management were prospectively enrolled in a multicenter cohort. Preoperative and postoperative (mean follow-up, 4.3 years) patient-reported outcome measures were obtained with a follow-up rate of 81.6% (621/761 hips), including 54 patients who underwent acetabular microfracture. Patient characteristics, radiographic parameters, intraoperative disease severity, and operative procedures were analyzed. Propensity matching using linear regression was used to match 54 hips with microfracture to 162 control hips (1:3) to control for confounding variables. Subanalyses of hips ≤35 and >35 years of age with propensity matching were also performed. RESULTS: Patients who underwent acetabular microfracture were more likely to be male (81.8% vs 40.9%; P < .001), be older in age (35.0 vs 29.9 years; P = .001), have a higher body mass index (27.2 vs 25.0; P = .001), and have a greater alpha angle (69.6° vs 62.3°; P < .001) compared with the nonmicrofracture cohort (n = 533). After propensity matching to control for covariates, patients treated with microfracture displayed no differences in the modified Harris Hip Score or Hip Disability and Osteoarthritis Outcome Score (P = .22-.95) but were more likely to undergo total hip arthroplasty (THA) (13% [7/54] compared with 4% [6/162] in the control group; P = .002), and age >35 years was associated with conversion to THA after microfracture. Microfracture performed at or before 35 years of age portended good outcomes with no significant risk of conversion to THA at the most recent follow-up. CONCLUSION: Microfracture of acetabular cartilage defects appears to be safe and associated with reliably improved short- to mid-term results in younger patients; modified expectations should be realized when full-thickness chondral lesions are identified in patients >35 years of age.

Langerhans Cell Histiocytosis in the Pediatric Spine Requiring Stabilization: A Literature Review and Report of 3 Cases.

CASE: This report describes 3 cases of Langerhans cell histiocytosis (LCH) of the cervical and thoracic spine in patients aged 4 to 10 years. Each patient had painful lytic spinal lesions with vertebral body collapse and posterior involvement suggesting instability requiring corpectomy, grafting, and fusion. All 3 patients were doing well at their most recent follow-up without pain or recurrence. CONCLUSION: Although LCH of the pediatric spine is usually successfully treated non-operatively, we recommend corpectomy and fusion when there is instability of the spinal column and/or severe stenosis. Posterior element involvement occurred in all 3 cases and may lead to instability.

The Effects of Physical Activity on Physeal and Skeletal Development.

¼: There is increasing evidence in the literature regarding the important health impact of and risk factors for injury in youth sport. ¼: Increasing pediatric and adolescent activity intensity, such as is seen in earlier single-sport focus and specialization, may be associated with morphological changes in the growing skeleton. ¼: Chronic subacute injury to the developing physes in the active child can lead to stress on the growth plate and surrounding tissues that induces developmental morphological changes in the joint. ¼: There is evidence to suggest that frequent participation in sports that place particular stress across the physes of the proximal humerus, the proximal femur, and the distal radius can be associated with an increased risk of inducing developmental and morphological changes that could lead to future joint dysfunction and premature degeneration. ¼: Additional research is necessary to better define the pathoetiology of activity-mediated morphological changes, as well as to create and validate parameters for safe involvement in competitive physical activities.

Can the Femoro-Epiphyseal Acetabular Roof (FEAR) Index Be Used to Distinguish Dysplasia from Impingement?

BACKGROUND: Classifying hips with structural deformity on the spectrum from impingement to dysplasia is often subjective and frequently inexact. Currently used radiographic measures may inaccurately predict a hip's morphological stability in borderline hips. A recently described radiographic measure, the Femoro-Epiphyseal Acetabular Roof (FEAR) index, has demonstrated an ability to predict stability in the borderline hip. This measure is attractive to clinicians because procedures can be used on the basis of a hip's pathomechanics. This study was designed to further validate and characterize the FEAR index in a skeletally immature population, in hips with dysplasia/femoroacetabular impingement (FAI), and in asymptomatic hips. QUESTIONS/PURPOSES: (1) What are the characteristics of the FEAR index in children and how does the index change with skeletal maturation? (2) How does the FEAR index correlate with clinical diagnosis and surgical treatment in a large cohort of symptomatic hips and asymptomatic controls? (3) How does the FEAR index correlate with clinical diagnosis in the borderline hip (lateral center-edge angle [LCEA] 20°-25°) group? METHODS: A total of 220 participants with symptomatic investigational hips with a clinical diagnosis of dysplasia or FAI between January 2008 and January 2018 were retrospectively collected from the senior author's practice. Investigational hips were excluded if they had any femoral head abnormalities preventing LCEA measurement (for example, Perthes disease), Tönnis osteoarthritis grade greater than 1, prior hip surgery, or prior femoral osteotomy. In the 220 participants, 395 hips met inclusion criteria. Once exclusion criteria were applied, 15 hips were excluded due to prior hip surgery or prior femoral osteotomy, and 12 hips were excluded due to femoral head deformity. A single hip was then randomly selected from each participant, resulting in 206 investigational hips with a mean age of 13 ± 3 years. Between January 2017 and December 2017, 70 asymptomatic control participants were retrospectively collected from the senior author's institutional trauma database. Control hips were included if the AP pelvis film had the coccyx centered over the pubic symphysis and within 1 to 3 cm of the superior aspect of the symphysis. Control hips were excluded if there was any fracture to the pelvis or ipsilateral femur or the participant had prior hip/pelvis surgery. After exclusion criteria were applied, 16 hips were excluded due to fracture. One hip was then randomly selected from each participant, resulting in 65 control hips with a mean age of 16 ± 8 years. Standardized standing AP pelvis radiographs were used to measure the FEAR index, LCEA, and Tönnis angle in the investigational cohort. Standardized false-profile radiographs were used to measure the anterior center-edge angle (ACEA) in the investigational cohort. Two blinded investigators measured the FEAR index with an intraclass correlation coefficient of 0.92 [95% CI 0.84 to 0.96]. Question 1 was answered by comparing the above radiographic measures in age subgroups (childhood: younger than 10 years; adolescence: 10 to 14 years old; maturity: older than 14 years) of dysplastic, FAI, and control hips. Question 2 was answered by comparing the radiographic measures in all dysplastic, FAI, control hips, and a subgroup of operatively or nonoperatively managed dysplasia and FAI hips. Question 3 was answered by comparing the radiographic measures in borderline (LCEA 20°-25°) dysplastic, FAI, and control hips. RESULTS: The FEAR index was lower in older dysplastic of hips (younger than 10 years, 6° ± 9°; 10 to 14 years, 4° ± 10°; older than 14 years, 5° ± 9°; p < 0.001) and control hips (younger than 10 years, -6° ± 5°; 10 to 14 years, -15° ± 4°; older than 14 years, -16° ± 7°; p < 0.001). The diagnosis and age groups were independently correlated with the FEAR index (p < 0.001). The relationship between the FEAR index and diagnosis remained consistent in each age group (p = 0.11). The FEAR index was higher in all dysplastic hips (mean 5° ± 10°) than in asymptomatic controls (mean -13° ± 7°; p < 0.001) and FAI hips (mean -10° ± 11°; p < 0.001). Using -1.3° as a cutoff for FAI/control hips and dysplastic hips, 81% (112 of 139) of hips with values below this threshold were FAI/control, and 89% (117 of 132) of hips with values above -1.3° were dysplastic. The receiver operator characteristics area under the curve (ROC-AUC) was 0.91. Similarly, the FEAR index was higher in borderline dysplastic hips than in both asymptomatic borderline controls (p < 0.001) and borderline FAI hips (p < 0.001). Eighty-nine percent (33 of 37) of hips with values below this threshold were FAI/control, and 90% (37 of 41) of hips with values above -1.3° were dysplastic. The ROC-AUC for borderline hips was 0.86. CONCLUSION: The FEAR index was associated with the diagnosis of hip dysplasia and FAI in a patient cohort with a wide age range and with varying degrees of acetabular deformity. Specifically, a FEAR index greater than -1.3° is associated with a dysplastic hip and a FEAR index less than -1.3° is associated with a hip displaying FAI. Using this reliable, developmentally based radiographic measure may help hip preservation surgeons establish a correct diagnosis and more appropriately guide treatment. LEVEL OF EVIDENCE LEVEL: III, diagnostic study.

Sex Differences in Clinical Outcomes Following Surgical Treatment of Femoroacetabular Impingement.

BACKGROUND: Sex-based differences in clinical outcomes following surgical treatment of femoroacetabular impingement remain largely uncharacterized; this prospective, multicenter study evaluated these differences both directly and adjusted for covariates. METHODS: Hips undergoing surgical treatment of symptomatic femoroacetabular impingement were prospectively enrolled in a multicenter cohort. Patient demographics, radiographic parameters, intraoperatively assessed disease severity, and history of surgical procedures, as well as patient-reported outcome measures, were collected preoperatively and at a mean follow-up of 4.3 years. A total of 621 (81.6%) of 761 enrolled hips met the minimum 1 year of follow-up and were included in the analysis; 56.7% of analyzed hips were female. Univariate and multivariable statistics were utilized to assess the direct and adjusted differences in outcomes, respectively. RESULTS: Male hips had greater body mass index and larger α angles. Female hips had significantly lower preoperative and postoperative scores across most patient-reported outcome measures, but also had greater improvement from preoperatively to postoperatively. The preoperative differences between sexes exceeded the threshold for the minimal clinically important difference of the modified Harris hip score (mHHS) and all Hip disability and Osteoarthritis Outcome Score (HOOS) domains except quality of life. Preoperative sex differences in mHHS, all HOOS domains, and Short Form-12 Health Survey physical function component score were greater than the postoperative differences. A greater proportion of female hips achieved the minimal clinically important difference for the mHHS, but male hips were more likely to meet the patient acceptable symptom state for this outcome. After adjusting for relevant covariates with use of multiple regression analysis, sex was not identified as an independent predictor of any outcome. Preoperative patient-reported outcome scores were a strong and highly significant predictor of all outcomes. CONCLUSIONS: Significant differences in clinical outcomes were observed between sexes in a large cohort of hips undergoing surgical treatment of femoroacetabular impingement. Despite female hips exhibiting lower baseline scores, sex was not an independent predictor of outcome or reoperation. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Why Does Hip Arthroscopy Fail? Indications and PEARLS for Revision Success.

The surgical treatment of femoroacetabular impingement has been shown to have successful early and mid-term clinical outcomes. Despite these favorable clinical outcomes that have been published in the literature, there is a subgroup of patients that present with continued or recurrent symptoms after surgical treatment. Not only has there been an increase in the number of hip arthroscopy procedures, but also there has been a corresponding increase in the number of revision hip arthroscopy and hip preservation surgeries. Previous studies have reported residual deformity to be the most common reason for revision hip arthroscopy. However, chondral, labral, and capsular considerations also are important when addressing patients not only in the primary but also, the revision setting. In this review, we outline the evaluation and treatment of the patient that presents with continued hip and groin pain after undergoing a hip.

Outcomes of periacetabular osteotomy for borderline hip dysplasia in adolescent patients.

Treatment of borderline acetabular dysplasia (lateral center edge angle ≥18°) remains controversial, and there is a paucity of literature focusing on outcomes in adolescent patients. The purpose of this study was to evaluate the outcomes of a periacetabular osteotomy (PAO) as surgical management of borderline acetabular dysplasia in adolescent patients. We performed a retrospective review of prospectively collected data and included patients ≤ 21 years of age that underwent PAO for borderline acetabular dysplasia. All patients had a minimum of 1-year follow-up. Outcomes were assessed using modified Harris Hip Scores (mHHS), Hip Outcome Scores (HOS) and international Hip Outcome Tool (iHOT-33). Descriptive and univariate statistical analyses were performed. This study included 33 adolescent patients (35 hips) with symptomatic, borderline acetabular dysplasia. The majority of patients was female (32 patients, 97%); half of all patients reported a history of hip pain for over 1 year; and seven patients had previous hip arthroscopy. In addition to PAO, seven hips (20%) underwent a concurrent hip arthroscopy at the time of surgery. There were significant improvements in mean mHHS, HOS-activities of daily living (ADL), HOS-Sport and iHOT-33 scores after surgery (P < 0.01). Minimal clinically important difference in outcome scores was achieved for over 90% of patients at a minimum of 1-year follow-up. Borderline acetabular dysplasia is a major cause of hip pain in adolescent patients. Patients with symptomatic borderline acetabular dysplasia report a significant benefit after a PAO to correct structural hip instability.

Morscher Osteotomy Through Surgical Dislocation Approach for True Femoral Neck Lengthening with Greater Trochanter Transposition.

BACKGROUND: Young adults presenting with hip pain can be affected by proximal femoral growth disturbances as seen in Legg-Calvé-Perthes disease (LCPD) or as a complication of surgical treatment of developmental dysplasia of the hip (DDH). In 1988, Morscher proposed a novel femoral neck lengthening osteotomy to address these issues. The purpose of this study was to evaluate the effectiveness and safety of the Morscher osteotomy as a procedure to complement the well-documented surgical hip dislocation, to increase femoral offset, to distalize the greater trochanter, and to increase the overall limb length. METHODS: This study was a retrospective case series from 3 hip-preservation-expert surgeons. Morscher osteotomies performed through a surgical dislocation approach by 3 surgeons between January 2008 and September 2019 were reviewed. Fifteen patients with a median age at surgery of 17 years (range, 13 to 28 years) and a minimum follow-up of 3 months (until union) were included. Surgical indications, clinical findings, comparative radiographic analyses including the change in horizontal femoral offset and the position of the greater trochanter, and complications were assessed. RESULTS: Surgical indications included DDH and LCPD. The horizontal femoral offset improved in all patients, to a median of 32.5 mm (range, 4 to 46.4 mm). The articular-trochanteric distance increased to >5 mm in all patients. Limb length improved by a median of 11.5 mm (range, 3 to 30 mm). Complementary periacetabular osteotomy was performed in 14 patients. The lateral center-edge angle and the acetabular index improved in patients with an associated periacetabular osteotomy, to a median of 28.2° (range, 9° to 37.7°) and 7.9° (range, 0° to 20°), respectively. Two patients demonstrated osteoarthritis progression from Tönnis stage 0 to stage 1, and 6 patients had a decrease of the joint space. Complications included 1 pulmonary embolism, 1 case of asymptomatic fibrous union of the greater trochanter, and 1 transient sciatic nerve palsy. CONCLUSIONS: The time-tested Morscher osteotomy indicated for complex proximal femoral reconstruction is effective in increasing horizontal femoral offset, distalization of the greater trochanter, and limb length. Combining the Morscher osteotomy with the versatility of surgical hip dislocation and the improved coverage capacity of periacetabular osteotomy proved complementary in the arsenal of hip preservation. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Surgical Treatment of Femoroacetabular Impingement: Hip Arthroscopy Versus Surgical Hip Dislocation: A Propensity-Matched Analysis.

BACKGROUND: Surgical treatment of femoroacetabular impingement (FAI) continues to evolve and is most commonly approached with either hip arthroscopy (HA) or surgical dislocation (SD) of the hip. The purpose of this study was to compare the outcomes of similar patients undergoing surgical treatment of FAI with either HA or SD. METHODS: A prospective multicenter cohort study of patients undergoing primary surgical treatment of FAI was performed. Follow-up at a minimum of 1 year (mean, 4.3 years) was available for 621 hips (81.7%), including 399 procedures with HA and 222 procedures with SD. Propensity scores were calculated and reflect the likelihood of surgical treatment with HA versus SD for a given set of covariates. Propensity scores allowed 1:1 matching to identify similar patients at baseline. After propensity matching, 128 matched pairs of patients who underwent HA and 128 matched pairs of those who underwent SD were included in the study. The primary outcome was the postoperative modified Harris hip score (mHHS); secondary outcomes included the Hip disability and Osteoarthritis Outcome Score (HOOS), the University of California Los Angeles (UCLA) activity score, and the Short Form-12 (SF-12) physical and mental subscores, as well as the rate of persistent symptoms, revision surgery, and total hip arthroplasty (THA). RESULTS: After propensity matching, the 2 groups exhibited similar distributions of all of the covariates that were included in the model. Both groups demonstrated significant improvements in all patient-reported outcomes (PROs). The final mHHS was not significantly different between the 2 matched groups (81.3 for the HA group versus 80.2 for the SD group, p = 0.67). Likewise, the HOOS pain subscale was similar at the time of final follow-up (77.6 versus 80.5, respectively, p = 0.32). No difference between the HA group and the SD group was identified in the rate of THA (0% and 3.1%, respectively, p = 0.41) and revision surgery (7.8% and 10.9%, respectively, p = 0.35); overall rates of persistent symptoms were 21.9% for the HA group and 24.4% for the SD group (p = 0.55). CONCLUSIONS: In a propensity-matched analysis of patients who were treated with either approach, patients undergoing HA or SD demonstrated similar outcomes at a mean of 4 years postoperatively. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Periacetabular osteotomy with or without arthroscopic management in patients with hip dysplasia: study protocol for a multicenter randomized controlled trial.

BACKGROUND: Hip dysplasia is one of the most common causes of hip arthritis. Its incidence is estimated to be between 3.6 and 12.8% (Canadian Institute for Health Information, Hip and knee replacements in Canada, 2017-2018: Canadian joint replacement registry annual report, 2019; Jacobsen and Sonne-Holm, Rheumatology 44:211-8, 2004). The Periacetabular Osteotomy (PAO) has been used successfully for over 30 years (Gosvig et al., J Bone Joint Surg Am 92:1162-9, 2010), but some patients continue to exhibit symptoms post-surgery (Wyles et al., Clin Orthop Relat Res 475:336-50, 2017). A hip arthroscopy, performed using a small camera, allows surgeons to address torn cartilage inside the hip joint. Although both procedures are considered standard of care treatment options, it is unknown whether the addition of hip arthroscopy improves patient outcomes compared to a PAO alone. To delay or prevent future joint replacement surgeries, joint preservation surgery is recommended for eligible patients. While previous studies found an added cost to perform hip arthroscopies, the cost-effectiveness to Canadian Health care system is not known. METHODS: Patients randomized to the experimental group will undergo central compartment hip arthroscopy prior to completion of the PAO. Patients randomized to the control group will undergo isolated PAO. Patient-reported quality of life will be the primary outcome used for comparison between the two treatment groups as measured by The International Hip Outcome Tool (iHOT-33) (Saberi Hosnijeh et al., Arthritis Rheum 69:86-93, 2017). Secondary outcomes will include the four-square step test and sit-to-stand (validated in patients with pre-arthritic hip pain) and hip-specific symptoms and impairment using the HOOS; global health assessment will be compared using the PROMIS Global 10 Score; health status will be assessed using the EQ-5D-5L and EQ VAS questionnaires (Ganz et al., Clin Orthop Relat Res 466:264-72, 2008) pre- and post-operatively. In addition, operative time, hospital length of stay, adverse events, and health services utilization will be collected. A sub-group of patients (26 in each group) will receive a T1rho MRI before and after surgery to study changes in cartilage quality over time. A cost-utility analysis will be performed to compare costs and quality-adjusted life years (QALYs) associated with the intervention. DISCUSSION: We hypothesize that (1) concomitant hip arthroscopy at the time of PAO to address central compartment pathology will result in clinically important improvements in patient-reported outcome measures (PROMs) versus PAO alone, that (2) additional costs associated with hip arthroscopy will be offset by greater clinical improvements in this group, and that (3) combined hip arthroscopy and PAO will prove to be a cost-effective procedure. TRIAL REGISTRATION: ClinicalTrials.gov NCT03481010 . Registered on 6 March 2020. Protocol version: version 3.

Single-incision Extraperiosteal Triple Innominate Osteotomy: Outcomes of an Updated Technique.

BACKGROUND: Since its original description, the triple pelvic osteotomy has undergone several modifications and refinements most often utilizing 3 or 2 incisions. Recently, a single-incision extraperiosteal technique has been described; however, little data exist on the outcomes of this procedure. METHODS: All patients undergoing single-incision triple osteotomy from 2 centers were retrospectively reviewed. Demographic data, underlying diagnosis, and preoperative radiographic data were recorded. Intraoperative details including estimated blood loss and type of postoperative immobilization were noted. Over the follow-up period, complications were recorded as were radiographic outcomes including lateral center edge angle, acetabular index, migration percentage, continuity of Shenton's line, and time to union. RESULTS: Twenty-eight hips (in 24 patients) underwent surgery at a mean age of 9.3 years (range, 6.5 to 13.8 y). Diagnoses included Trisomy 21 (9), developmental dysplasia of the hip (5), Charcot-Marie-Tooth (3), and neuromuscular disease (9) among others. The mean estimated blood loss was 135 mL (±98 mL) and most patients were immobilized in an abduction brace or single-leg spica cast for an average of 7.6±2.2 weeks after surgery before weight-bearing was advanced. At a mean follow-up of 3.0±2.2 years, the lateral center edge angle improved from an average of 1±14 degrees preoperatively to 35±7 degrees, the acetabular index from 27±11 degrees to 2±5 degrees, and the migration percentage from 44%±21% to 3%±5%. Fourteen hips had frank instability before surgery and 20 had a break in Shenton's line >5 mm. At most recent follow-up, all but 1 hip was stable (93%) and all had restoration of Shenton's line (100%). Radiographic union occurred at a mean of 14 weeks (±11 wk). One patient developed an ischial nonunion that underwent further surgery, 1 had premature closure of the triradiate cartilage, and 1 patient with transverse myelitis developed Charcot arthropathy. There were no other complications in this series. CONCLUSIONS: In this dual-center retrospective series, the single-incision triple innominate osteotomy was extremely effective for improving acetabular coverage and stabilizing unstable hips in a variety of underlying diagnoses with an acceptably low rate of complications. LEVEL OF EVIDENCE: Level IV-case series.

Lateral Center-Edge Angle Is Not Predictive of Acetabular Articular Cartilage Surface Area: Anatomic Variation of the Lunate Fossa.

BACKGROUND: Surgical treatment of symptomatic femoroacetabular impingement (FAI) and dysplasia requires careful characterization of acetabular morphology. The lateral center-edge angle (LCEA) is often used to assess lateral acetabular anatomy. Previous work has questioned the LCEA as a surrogate for acetabular contact/articular cartilage surface area because of the variable morphology of the lunate fossa. HYPOTHESIS: We hypothesized that weightbearing articular cartilage of the acetabulum would poorly correlate with LCEA secondary to significant variation in the size of the lunate fossa. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: Patients with 3D CT imaging undergoing either hip arthroscopy or periacetabular osteotomy for FAI or symptomatic hip instability were retrospectively identified. The LCEA and femoral head diameter were measured on an anteroposterior pelvis radiograph. Patients were grouped according to their lateral acetabular coverage as undercoverage (LCEA, <25°), normal coverage (LCEA, 25°-40°), or overcoverage (LCEA, >40°). Patients were randomly identified until each group contained 20 patients. The articular surface area was measured from preoperative 3D CT data. Linear regression analysis was performed to examine the relationship between articular surface area and LCEA. Continuous and categorical data were analyzed utilizing analysis of variance and chi-square analysis. Statistical significance was set at P < .05. RESULTS: No difference in age (P = .52), body mass index (BMI) (P = .75), or femoral head diameter (P = .66) was noted between groups. A significant difference in articular surface area was observed between patients with undercoverage and those with overcoverage (20.4 cm2 vs 24.5 cm2; P = .01). No significant difference was identified between the undercoverage and normal groups (20.4 cm2 vs 23.3 cm2; P = .09) or the normal and overcoverage groups (23.3 cm2 vs 24.5 cm2; P = .63). A moderate positive correlation was observed between LCEA and articular surface area across all patients (r = 0.38; P = .002) but not when patients with undercoverage were excluded (r = 0.02; P = .88). Significant variation in surface area was observed within each group such that no patient in any group was outside of 2 SDs of the means of the other groups. When patients were categorized into quartiles established by the articular surface area for the entire population, 40% of patients with overcoverage were observed in the first or second quartile (lower area). CONCLUSION: Lateral acetabular undercoverage based on the LCEA (<25°) correlates with decreased acetabular surface area. Normal or increased acetabular coverage (LCEA, >25°), however, is not predictive of increased, normal, or decreased acetabular surface area.

Impingement-Free Hip Flexion in Asymptomatic Young Adult Women.

BACKGROUND: Ultrasound-assisted measurement of hip flexion has demonstrated that hip flexion has been historically overestimated in men. To our knowledge, assessment of hip flexion in women using similar methods has not been reported. Establishing normative values for hip flexion is vital to aid diagnosis, management, and future research. Therefore, we asked 2 questions: (1) At what range of midsagittal hip flexion do soft-tissue impingement and femoroacetabular abutment occur in asymptomatic young adult women? (2) Do radiographic findings on a supine anteroposterior pelvic radiograph correlate with ultrasound-assisted measurements of hip flexion? METHODS: Fifty-five asymptomatic adult women volunteers (107 hips) underwent ultrasound-assisted assessment of hip flexion. Hip flexion was recorded at the initiation of labral contact and at bone-on-bone contact. Recorded motion was correlated with common radiographic measurements of hip morphology as observed on a supine anteroposterior pelvic radiograph. RESULTS: The mean age of the subjects was 26 ± 3 years (range, 21 to 35 years), and the mean body mass index was 23 ± 3 kg/m (range, 17 to 31.6 kg/m). Mean impingement-free and maximum midsagittal passive flexion were 72° ± 8° (95% confidence interval [CI], 70° to 74°) and 101° ± 11° (95% CI, 99° to 103°), respectively. There were no significant correlations between radiographic measurements of hip morphology and ultrasound-measured hip range of motion. CONCLUSIONS: Observed hip flexion in the asymptomatic hips of young women is substantially less than has been historically reported. Morphologic features that are measurable on anteroposterior pelvic radiographs do not correlate with ultrasound-measured hip flexion. Diagnosis of hip disorders and treatments that are designed to alter hip range of motion should be based on normative data. Future studies regarding surgical restoration and/or preservation of hip flexion should be based on an understanding of normal hip range of motion. CLINICAL RELEVANCE: Ultrasound-assisted hip flexion measurement established normative values to guide surgical restoration and/or preservation of hip flexion.

Does Compensatory Anterior Pelvic Tilt Decrease After Bilateral Periacetabular Osteotomy?

BACKGROUND: The kinetic link among the lumbar spine, pelvic tilt, and the hip has been hypothesized, but this relationship requires further study in acetabular dysplasia. Anecdotal reports suggest that patients may compensate for acetabular dysplasia with an involuntary increase in anterior pelvic tilt; it is not known if this relationship is affected by acetabular reorientation. QUESTIONS/PURPOSES: (1) Does compensatory pelvic tilt decrease on preoperatively obtained standing AP pelvis radiographs compared with those obtained at a minimum of 6 months after bilateral periacetabular osteotomy (PAO)? (2) Does a modified surrogate measurement of pelvic tilt, the pubic symphysis to sacroiliac (PS-SI) index, correlate with a physical synthetic bones model in which pelvic tilt can be directly measured? (3) Can the PS-SI index demonstrate high interrater reliability? METHODS: We assessed the surgical records of one surgeon, who participates in the longitudinally maintained Academic Network of Conservational Hip Outcomes Research (ANCHOR) registry, for patients who had undergone the second side of a staged bilateral PAO between 2007 and 2016; there were 113 such patients. Of those, 70 (62%) were lost to followup within 6 months of the second PAO or did not have adequate imaging studies, and another three (3%) were excluded for prespecified reasons, leaving 40 (35%) for evaluation in this retrospective study. Standing preoperative and most recent postoperative AP pelvis radiographs were used to measure the Tönnis angle, anterior wall index, posterior wall index, lateral center-edge angle, pubis symphysis-to-sacrococcygeal junction distance, and the PS-SI index. The most recent radiographs were obtained at a mean of 16 ± 6 months after the second PAO. We chose 6 months as the minimum because at this time point, the majority of patients have reached their maximum clinical improvement and are no longer limited by postoperative muscle dysfunction. Statistical analysis was performed using the intraclass correlation coefficient (ICC) for interrater reliability and paired t-tests for assessing change in measurements from pre- to postoperative. Additionally, a model was created using a physical synthetic bones model in which pelvic tilt could be directly measured. This model was secured through bilateral acetabuli on a mount and rotated through 5° increases in pelvic tilt. AP pelvis radiographs were obtained at each point, the PS-SI index was measured, and a regression analysis performed to evaluate for trend. RESULTS: Overall, 37 of 40 patients (93%) had a decrease in pelvic tilt, as measured by the PS-SI index. The mean amount of pelvic tilt as measured by the PS-SI index decreased after surgery when comparing the preoperative with latest radiographs on this parameter (97 ± 14 mm versus 89 ± 13 mm, mean difference 8 ± 9 mm; 95% confidence interval, -11 to -5; range 17 increase to 24 decrease, p < 0.001). A linear relationship between pelvic tilt and PS-SI index (PS-SI index = 5.0° + 3.6° tilt, R = 0.99) was identified in the synthetic bones validation model. Finally, the interrater reliability was found to be excellent for the PS-SI index preoperatively (ICC = 0.986) and postoperatively (ICC = 0.988). CONCLUSIONS: We found a modest reduction in anterior pelvic tilt after bilateral PAO. This finding suggests that acetabular reorientation affects pelvic position. In clinical practice, patients with acetabular dysplasia may compensate with dynamic and reversible changes in pelvic tilt. The PS-SI index is a reproducible tool to measure the height of the pelvic inlet as an assessment of pelvic tilt. In the future, clinical studies should evaluate the clinical implications of these radiographic findings, including the assessment of back pain, which although multifactorial may be influenced by pelvic tilt. LEVEL OF EVIDENCE: Level III, therapeutic study.

Determining Hinge Abduction in Legg-Calvé-Perthes Disease: Can We Reliably Make the Diagnosis?

BACKGROUND: Although hinge abduction is recognized as an important finding in children with Legg-Calvé-Perthes disease, variable diagnostic criteria exist. The purpose of this study was (1) to test the interobserver and intraobserver agreement of the current definition of hinge abduction and (2) to develop consensus regarding key diagnostic features that could be used to improve our diagnostic criteria. METHODS: Four orthopaedic surgeons with subspecialty pediatric hip interest independently assessed 30 randomly ordered cases of Legg-Calvé-Perthes disease. Each case included 2 fluoroscopic images of hip arthrograms (anteroposterior and abduction views). Surgeons graded the cases in a binary manner (hinge/no-hinge) on 2 separate occasions separated by a 4-week interval. Following reliability testing and comprehensive review of the literature, consensus-building sessions were conducted to identify key diagnostic features. Surgeons then regraded a new series of cases. Interobserver and intraobserver agreement between first/second and third/fourth readings were assessed using the Fleiss κ. RESULTS: Interobserver κ for hinge abduction between the first and second surveys was 0.52 (with 0.41 to 0.60 considered moderate agreement), compared with 0.56 for the third and fourth surveys. First and second reading intraobserver agreement ranged from 0.59 to 0.83 compared with 0.75 to 1.00 for third and fourth reading. Consensus sessions identified several key diagnostic factors including: adequate visualization of the labral contour and ability of the lateral epiphysis to slip below the chondrolabral complex in abduction. Medial dye pooling, often due to asphericity of the femoral head, was not found to be a useful diagnostic criterion. CONCLUSIONS: Despite a combined experience of over 70 years among the reviewers, we found just slightly better than 50:50 agreement in what constitutes hinge abduction. Consensus discussions did improve our agreement but these modest changes emphasize how difficult it is to develop reliable diagnostic criteria for hinge abduction. As a result, we caution against using hinge abduction as an inclusion criteria or outcome measure for research purposes, as the diagnostic agreement can be inconsistent. LEVEL OF EVIDENCE: Level III-diagnostic study.

Evidence-based Recommendations for Pediatric Orthopaedic Practice.

BACKGROUND: The evidence-based approach to guide clinical practice has gained great importance in the medical field. High-quality evidence is of paramount importance to inform clinical decision-making and optimize patient outcomes. The generation of high-quality evidence relies on sound methodology and study design to facilitate appropriate interpretation and subsequent application of the clinical findings. The purpose of this review is to objectively critique the methodological design and clinical findings of 2 pediatric orthopaedic studies on children with cerebral palsy (CP) to assess their potential to impact clinical practice. METHODS: This is the second in a series of evidence-based reviews in pediatric orthopaedics. The pediatric orthopaedic literature was reviewed for randomized controlled trials (RCTs) published in 2015 and 2016. One RCT was selected from the journal Pediatrics, and one RCT was selected from the journal Developmental Medicine and Child Neurology, both investigating the use of botulinum toxin for the treatment of spastic equinus in children with CP. These RCTs were subjected to in-depth methodological review by orthopaedic surgeons with advanced research degrees and a PhD researcher. Two clinical experts then reviewed the articles to rate the clinical impact or value of each study. Methodological and clinical reviews were compiled, and a final recommendation on impact to change clinical practice was made based on both review components at the consensus of the panel. RESULTS: The first study reviewed investigated the single-dose efficacy and safety of botulinum neurotoxin type-A (1BoNT-A) in children with CP-associated spasticity and equinus foot deformity. The reviewers deemed the placebo-controlled study to be of sound design, and conclusions appropriate for the methodology used and clinical findings. Although findings suggest 1BoNT-A may provide benefit in treating equinus foot deformity, the optimal dose for achieving maximal impact on functional improvement remains undetermined. The second study reviewed investigated the impact of multiple dosing schedules on spastic equinus in CP. Although of relatively sound design, this study was limited by a small sample size and lack of justification for the chosen effect size. Without further study, no recommendation to change clinical practice could be made. CONCLUSIONS: Both RCTs reviewed were superiority studies, the first demonstrating efficacy of botulinum toxin over placebo, the second showing no significant difference in 4- and 12-monthly botulinum toxin injections. SIGNIFICANCE: Despite a positive result demonstrating an effect of botulinum toxin treatment on spastic equinus in CP, the long-term functional impact and optimal dose remains to be determined. In addition, the negative result in the second study demonstrates the need for a noninferiority trial design to appropriately demonstrate no difference between 2 treatment options.

Analysis of Femoral Version in Patients Undergoing Periacetabular Osteotomy for Symptomatic Acetabular Dysplasia.

INTRODUCTION: A paucity of information exists on the range of femoral version, its effect on hip stability, clinical examination, and presentation in patients with symptomatic acetabular dysplasia. The purpose of this study was to describe the range of version in symptomatic acetabular dysplasia, the association between femoral version and proximal femoral morphology and degree of dysplasia, and the effect of version on clinically measured hip range of motion and on preoperatively measured hip outcome scores. METHODS: We reviewed 314 patients prospectively enrolled in a longitudinal clinical study on periacetabular osteotomy between January 2014 and August 2015 and measured femoral version, morphologic characteristics of the upper femur and acetabulum, and preoperative clinical outcome scores. RESULTS: The average femoral version was 19.7° ± 11.2° (range, -20° to 50°). Femoral version correlated strongly with clinically measured hip range of motion but did not correlate linearly with either radiographic severity of acetabular dysplasia or preoperative symptomatology. DISCUSSION: Despite concerns that transverse plane femoral anatomy influences the stability of the hip joint after skeletal maturity, we did not find a statistical association between femoral version and severity of dysplasia or presenting symptomatology. This finding suggests that femoral version is not a major influence on the clinical presentation of acetabular dysplasia. LEVEL OF EVIDENCE: Level IIIb.